Internetworking technologies handbook [4th ed] 9781587051197, 1587051192

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

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The uIpdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of con s Used in Th is Book essentCom ial man an dd Sy cuntt taxingedg t ech nologies. Conv ente ions I n tr oduct ion Object Con ciseiv es ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Upd ates t hpert e Fourt nov ice t ot oex . h Edit ion Audience

New chaption er s include cov erag e of im por t ant t opics like VoI P and EAP Organizat Ack nowledgmen ts an d Con t ribut ors

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Thir d Edit ion Con t ribut ors First Edition t ribut ors Aut h ored byCon Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Part I . I nt rodu ction t o I nt ern et work ing

I n t ern et w orpter k in1. g Tech Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Cha I nt ernnologies et work ing Basics enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing What I s an I nt ernet work ? t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Open Sy st em I nt ercon nect ion Ref erence Model indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . n form ion Fo rmat Com plet e I w it h atnew an d us pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, I SO Hierarchy of ks plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all and speed, t h is book isNetwor a com ed and Conn ect ion of lessex Net workise. Serv ices net w or kinCon g pnect rofion-Orient essionals, r egar dless pert I n tern et wor k Addressing

Reader s wFlow ill obt a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Conain t rol Basics har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Er ror-Ch eck in g Basics a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Mu ltiplexing Basics t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Organiza tionns ot only t o new n et wor k ing concep t s, but also t o old er , legacy Cov erag e Stisandards also ext end ed mar in y g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich syst em s, Sum pr ovid Rev iew Qu est pr of essionals oper ation e. sTools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ovion e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient For More I nfo rmat decisionsCha for t h eir net w ork pter 2. I nt rod uct ion s. t o LAN Pr oto cols What I s a LAN? LAN Prot ocols and t he OSI Ref erence Model LAN Media- Access Met ho ds LAN Tran smissio n Meth ods

LAN Topologies LAN Dev ices Rev iew Qu est ion s For More I nfo rmat ion Cha pter 3. I nt rod uct ion t o WAN Techn olo gies What I s a WAN? Point - t o-Poin t Lin ks

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Circu it Swit ch ing

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Pack et Swit ching I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion WAN Virt u al Circu it s By Cisco Systems, Inc. WAN Dialup Services WAN Dev ices Pub lish er: Cisco Press Rev iew Qu est ion s Pub Dat e: Sep tem ber 1 1, 2 003 For More I nfo rmat ion I SBN: 1- 58 705 -1 19 -2 Cha pter 4. I nt rod uct ion t o Cisco I OS Soft ware Pages: 11 28 System Arch itect u re Cisco I OS CLI Deb ugging and Lo gging Reloading and Upgr ading Sum mar y

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Revdiew ionedg s essent ial an cuQu t test inge t ech nologies. For More I nfo rmat ion Cha pter 5. Bridging and Swit ch ing Basics

Con cise v iew sanofd Swit t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom What ov Ar eerBridges ches? nov ice t o ex pert . Lin k La yer Dev ice Ov er view

pes ofer Bridges New Tychapt s include cov erag e of im por t ant t opics like VoI P and EAP Ty pes of Swit ches

Cov erag e Qu of est cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Rev iew ion s For More I nfo rmat ion

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Cha pter 6. Rout ing Basics

ing? I n t ern et w What or k inI sg Rout Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Rou tin g Com pon ts enables net w or kin g p r en ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Rou tinMast g Algorit s t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t echnologies. er hm t he indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Net work Prot ocols Com plet e Rev w itiew h new ansd u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Qu est ion and speed, t h is7. book is a com plet an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Cha pter Net work Managem en t eBasics net w or kin g p rof essionals, r egar dless of ex pert ise. I n tr oduct ion

I s Net Reader s wWhat ill obt ainwork a gMan reatagemen er unt? der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Managem entser Arch har dw ar e,Net prwork ot ocols, and v itect icesu re inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on I SO Net work Model a b r oad r ang e of intManag egr alemsyent st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re Rev coniew cept comp Qu est ion s r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Part I I . LAN Prot ocols syst em s,Cha prpter ovid in g a e r ealist 8. Et hernm etor Techn ologiesic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Back groun d pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Et h er net —A Br ief Histo ry decisions for t h eir net w ork s. Et h er net Net work Element s Et h er net Net work Topologies an d St ructu res The I EEE 802 .3 Logical Relat ionsh ip t o t he I SO Ref er en ce Mo del The Et hern et MAC Su blayer The Et hern et Phy sical Lay ers

System Con siderat ions Sum mar y Rev iew Qu est ion s Cha pter 9. Fib er Dist ribut ed Dat a I nt erface I n tr oduct ion FDDI Tran smission Media FDDI Specif icat ions

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FDDI Stat ion -At t achm en t Ty pes

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FDDI Fault Toleran ce I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion FDDI Frame Fo rmat By Cisco Systems, Inc. Copper Dist ribu t ed Dat a I n t erf ace Sum mar y Pub lish er: Cisco Press Rev iew Qu est ion s Pub Dat e: Sep tem ber 1 1, 2 003 Part I I I . WAN Tech nologies I SBN: 1- 58 705 -1 19 -2 Cha pter 10 . Fram e Relay Pages: 11 28 I n tr oduct ion Fram e Relay Dev ices Fram e Relay Virt ual Circuit s Con gest ion -Con t rol Mech anism s Fram e Relay Local Man agemen t I nt erf ace

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Fram Relay Netedg workeI mplemen ta tion essent ial an d ecu t t ingt ech nologies. Fram e Relay Fram e Format s Sum mar y

Con cise ovQu erest v iew Rev iew ion ss of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Cha pter 11 . Hig h-Speed Serial I nt erface

tr oducter ion New I nchapt s include cov erag e of im por t ant t opics like VoI P and EAP HSSI I nt erface Basics

Cov erag of cut HSSI e Operat iont ing edge t echn ologies lik e opt ical n et wor k ing and st or age Sum mar y

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Rev iew Qu est ion s

Cha I n t egr at ed Ser vices Digit al Net I n t ern et w orpter k in12 g .Tech nologies Hand book , work Four t h Ed it ion , is a com pr ehensive refer ence t hat I n tr oduct ion enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing I SDN Mast Dev ices t echnologies. er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Ser vices Com plet e I w it hSpecif newication an d su pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, SDN and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Sum mar y net w or kin g p rof essionals, r egar dless of ex pert ise. Rev iew Qu est ion s

13ain . Poin o-Po in Reader sCha w illpterobt a tg-treat ert Pro untocol der st an ding

of LAN and WAN n et w or k ing, p ar t icu lar ly t h e tr oduct ion har dw ar e,I npr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on PPP Comp s al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions a b r oad r ang e of onent int egr t o en su re Gen coneral cept comp Operat ion r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e Phy is sical alsoLay ext n ot sonly t o new n et wor k ing concep t s, but also t o old er , legacy erend Requed irement syst em s, PPP pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Link Layer pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease PPP Link- Cont rol Prot ocol pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Sum mar y decisions for t h eir net w ork s. Rev iew Qu est ion s Cha pter 14 . Swit ched Mult imegabit Dat a Ser vice I n tr oduct ion SMDS Net work Co mpon en t s SMDS I n terf ace Pr oto col

Dist ribut ed Queue Du al Bus SMDS Access Classes SMDS Addressing Overv iew SMDS Reference: SI P Lev el 3 PDU Form at SMDS Reference: SI P Lev el 2 Cell Forma t Sum mar y Rev iew Qu est ion s

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Cha pter 15 . Dialup Techn olo gy

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I n tr oduct ion I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion A Shor t Dialu p Tech nology Backgr ound By Cisco Systems, Inc. Dialup Connect iv it y Techn ology Dialup Meth ods Pub lish er: Cisco Press Ben efit s and Dra wback s Pub Dat e: Sep tem ber 1 1, 2 003 Sum mar y I SBN: 1- 58 705 -1 19 -2 Rev iew Qu est ion s Pages: 11 28 For More I nfo rmat ion Cha pter 16 . Synch ronou s Dat a Link Cont rol and Deriv at ives I n tr oduct ion SDLC Ty pes and Topologies SDLC Fram e Form at

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Derd ivat Prot oco ls e t ech nologies. essent ial an cuive t t ingedg Sum mar y Rev iew Qu est ion s

ConCha cise iew pterov 17er . v X.2 5 s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . I n tr oduct ion

5 Dever ices an d Pro tocol New X.2 chapt s include covOperat eragion e of im por t ant t opics like VoI P and EAP The X. 25 Pr oto col Suit e

Cov erag of ecut t ing LAPB e Fram Form at edge t echn ologies lik e opt ical n et wor k ing and st or age X.1 21 Address For mat

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Sum mar y

est ionnologies s I n t ern et w Rev or kiew in gQuTech Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Cha pter 18 . Virt ual Priv at e Net work ( VPNs) enables net w or kin g p r ofessionals t os un derst and an d im plem en t cont em por ar y int er net w ork ing VPN Def init ion t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how VPN App lica tiont so incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e I w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, PSec and speed, t h is2 Tun book a com e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all La yer nelinis g Prot ocol plet ( L2 TP) net w or kin g p rof essionals, r egar dless of ex pert ise. MPLS VPNs

mar yain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Reader s wSum ill obt Qu est ionand s har dw ar e,Rev priew ot ocols, ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on For More ion sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions a b r oad r ang e of I nfo intrmat egr al t o en su con r eh Techn en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . PartreI V. Mucept lt iservcomp ice Access ologies Cov eragCha e ispter also ext end ed n ot only o newlognies et wor k ing concep t s, but also t o old er , legacy 19 . Voice/ Dat a I nt egrat ion tTechno syst em s, Ipr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich n tr oduct ion pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Advances in Applicat ions pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient New World Voice Tech nologies decisions for t h eir net w ork s. Voice Net work ing Voice ov er ATM Voice ov er Fram e Relay Voice over I P Qualit y of Serv ice for VoI P

Gen eral MGCP Overv iew Gen eral SI P Tut orial Skin ny Client Cont rol Prot ocol (SCCP) Com parison an d Con tr ast of t h e Various VoI P Signa lin g Alt er nat ives Evolu tion of Solut ion s f or Voice over Dat a Sum mar y Rev iew Qu est ion s

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For More I nfo rmat ion

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Cha pter 20 . Wireless Tech nologies I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Wireless Con cepts By Cisco Systems, Inc. Radio Fu ndam ent als NLOS Wireless: Ov ercomin g Mult ipat h Sign als in NLOS High Speed Pub lish er: Cisco Press Spread Spect rum Pub Dat e: Sep tem ber 1 1, 2 003 Elem en t s of a Tot al Netwo rk Solut ion I SBN: 1- 58 705 -1 19 -2 Wireless Local-Area Networ ks ( WLANs) Pages: 11 28 Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Glossary Term s Cha pter 21 . Digit al Subscriber Lin e

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of I n trdoduct essent ial an cu tion t ing- edg e t ech nologies. Asy mm etr ic Digita l Subscr iber Lin e Signaling and Modu lat ion

Con cise ov erDSL v iew s ofologies t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Addit io nal Techn nov ice t o ex pert . Sum mar y

iew Qu ion s New Rev chapt erest s include cov erag e of im por t ant t opics like VoI P and EAP For More I nfo rmat ion

CovCha erag of. cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age ptere22 Cable Access Techn ologies I n tr oduct ion

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Evolu tion f rom One-Way Br oadcast to Two- Way Hy brid Fiber Coax

at g io ns and nologies Specif icat ions of t he HFC, Plant I n t ern et w Lim or kitin Tech Hand book Four t h Ed it ion , is a com pr ehensive refer ence t hat DOCSI S St an dards, Signaling Prot ocols, and Applicat ionds im plem en t cont em por ar y int er net w ork ing enables net w or kin g p r ofessionals t o un derst and an DOCSIMast S Hardware t an dcep Result Service Capabilitan iesd devices used in t oday ' s net w ork ing t echnologies. er t heDeploy t er mms,en con t s,ing t echn ologies, indu st ry . Lear how St o incorions por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Fut ur enDOCSI Applicat Com plet e Sum w itmar h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, y and speed, t h is book Rev iew Qu est ionis s a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. For More I nfo rmat ion

23ain . I n taroduct ioner t o un Optder ical st Techno lo giesof Reader sCha w illpterobt g reat an ding

LAN and WAN n et w or k ing, p ar t icu lar ly t h e Opt ical and Net work har dw ar e,What pr otI socols, serinvg?ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Gen eralized lt ipralot ocol a b r oad r ang e of intMu egr sy stLabel em sSwitching and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re G.ASON con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e Opt is ical alsoCon ext n otNet only tr olend Planed e User workt o I n tnew er facen et wor k ing concep t s, but also t o old er , legacy syst em s, Opt pr ovid in g a m or e r ealist ic pict urNet e work of t he realical Con tr ol Plan e Op tical Net work -t oI n t er face w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Nex t -Generat ion Prot ect ion and Restor at ion pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Sum mar y decisions for t h eir net w ork s. Rev iew Qu est ion s For More I nfo rmat ion Cha pter 24 . VoI P H. 32 3 Net work Devices H. 32 3 Prot ocol Su it e

Session I nit iat ion Prot ocol ( SI P) Con nect ing VoI P Net work s with t h e SS7 Net work Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Glossary Term s Cha pter 25 . Dynam ic Packet Transpor t/ Spat ial Reuse Prot ocol

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DPT Arch itect u re

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SRP Ban dwidth Opt imiza tion I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion SRP Pa cket Priorit y By Cisco Systems, Inc. SRP Fairn ess Algorit hm DPT Resiliency Pub lish er: Cisco Press Topology Disco very Pub Dat e: Sep tem ber 1 1, 2 003 DPT/ SRP Pack et Forma ts I SBN: 1- 58 705 -1 19 -2 SRP Version 2 Gen eric Header Pages: 11 28 SRP Dat a Pack et SRP Con t rol Pa cket Mu ltica st Suppor t Sum mar y Rev iew Qu est ion s

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of For dMore rmat ione t ech nologies. essent ial an cu tItnfo ingedg Glossary Term s Cha pter 26 . Ext ensible Au t hent icat ion Prot ocol (EAP)

Con cise ov er v iew The EAP Prot ocol s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Usin g RADI US for EAP Au t hent icat ion

TypicalerAu icat ioncov Conv ersateion New Achapt s t hent include erag of im por t ant t opics like VoI P and EAP PKI Su pport wit h EAP

Cov erag e of EAP I mp lemcut enttating ionsedge t echn ologies lik e opt ical n et wor k ing and st or age Sum mar y

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Rev iew Qu est ion s

I nfo rmat ion I n t ern et w For or kMore in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Part V. Bridging and Swit ch ing enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Cha pter Mast 27 . Tra t Bridging t echnologies. er nsparen t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n howBr tidogin incor porion at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Tran sparent g Operat Com plet e Fram w it he Forma new tan d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, h is Qu book Revt iew est ionis s a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. For More I nfo rmat ion

28ain . MixaedMediaer Bridging Reader sCha w illpterobt g reat un der st an ding

of LAN and WAN n et w or k ing, p ar t icu lar ly t h e groun d har dw ar e,Back pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Tran slat Challenges a b r oad r ang e ofionint egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re Tran conslat cept comp r eh ional Bridgin g en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e Sourceis alsoRout ext end ed only t o new n et wor k ing concep t s, but also t o old er , legacy e Tr anspar n enot t Bridging syst em s, Rev pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich iew Qu est ion s pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease For More I nfo rmat ion pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Cha pter 29 . Sour ce- Rout e Bridg in g decisions for t h eir net w ork s. Back groun d SRB Algorit hm Fram e Forma t Rev iew Qu est ion s For More I nfo rmat ion

Cha pter 30 . LAN Swit chin g an d VLANs Hist ory LAN Switch Operat ion LAN Switch and th e OSI Model Rev iew Qu est ion s For More I nfo rmat ion Cha pter 31 . Asy nch ronou s Transf er Mode Swit ching

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St andards

I ndex

ATM Dev ices an d t h e Net work Env ironm ent I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion ATM Cell Header Form at By Cisco Systems, Inc. ATM Serv ices ATM Swit ch in g Operat ions Pub lish er: Cisco Press ATM Ref erence Model Pub Dat e: Sep tem ber 1 1, 2 003 ATM Add ressing I SBN: 1- 58 705 -1 19 -2 ATM Conn ect ion s Pages: 11 28 ATM and Mult icast ing ATM Qu ality of Serv ice ATM Sign aling and Conn ect ion Est ablishm en t ATM Conn ect ion -Ma nagemen t Messages PNNI

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of I n tegrat Localedg Man e agement I nt erfa ce essent ial an d cued t t ingt ech nologies. LAN Em ulat ion Mu ltipr oto col over ATM

Con cise ovQu erest v iew Rev iew ion ss of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . For More I nfo rmat ion

Chachapt pter 32er . s MPLS New include

cov erag e of im por t ant t opics like VoI P and EAP

MPLS Term inology

Cov erag of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age MPLS eOperat ions MPLS/ Tag- Swit ch ing Archit ectu re

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Hierarchical Ro ut ing

Virtnologies ual Priv at eHand Net work s I n t ern et w MPLS-Based or k in g Tech book , Four t h Ed it ion , is a com pr ehensive refer ence t hat MPLS Qualit y of Serv ice enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing MPLS Mast Traf ficer En gineering t echnologies. t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Sum mar y Com plet e Rev w itiew h new ansd u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Qu est ion and speed, t h is book is ion a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all For More I nfo rmat net w or kin g p rof essionals, r egar dless of ex pert ise. Cha pter 33 . Dat a-Link Swit chin g

groun d a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Reader s wBack ill obt ain t rast ed wit hser SourceRout e olv Bridging har dw ar e,DLSw pr otCon ocols, and v ices inv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on DLSwe SNA Su pport a b r oad r ang of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re DLSw con cept comp r eh sion Swit cht o-Swit ch en Prot ocol and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e DLSw is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Operat ion syst em s, DLSw pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Message Form at s pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Rev iew Qu est ion s pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Part VI . Net work Prot ocols decisions for t h eir net w ork s. Cha pter 34 . Open Sy st em I n terco nnect ion Prot ocols Back groun d OSI Net work ing Prot ocols Rev iew Qu est ion s Cha pter 35 . I n t er net Prot oco ls

Back groun d I n tern et Prot ocol Address Reso lu t ion Prot ocol Ov erv iew I n tern et Rout ing I n tern et Cont rol Message Prot ocol Tran smissio n Co nt rol Prot ocol User Dat agram Prot ocol

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I n tern et Prot ocols Application Layer Prot oco ls

I ndex

Sum mar y I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Rev iew Qu est ion s By Cisco Systems, Inc. Cha pter 36 . I Pv6 Descript ion of I Pv 6 Pack et Header Pub lish er: Cisco Press Hex adecimal "Hex " Pub Dat e: Sep tem ber 1 1, 2 003 Addressing Descript io n I SBN: 1- 58 705 -1 19 -2 Broadcast in g Met ho ds Pages: 11 28 Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Cha pter 37 . Net Ware Prot ocols Back groun d

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Netd Ware ia Access essent ial an cu tMed t ingedg e t ech nologies. I n tern et wor k Pack et Ex ch ange Ov erv iew I PX Encap sulat ion Types

Con cise ovAdv er vert iew s oft tProt echn Ser vice isemen ocololog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Net Ware Tr anspor t Lay er

Wareer Upper-Lay er Prot ocols and New Net chapt s include cov erag e Services of im por t ant t opics like VoI P and EAP I PX Pack et For mat

Cov erag e of Sum mar y cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Rev iew Qu est ion s

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Cha pter 38 . AppleTalk

n trkoduct I n t ern et w Ior in g ion Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat AppleTalk Com pon en t s t o un derst and an d im plem en t cont em por ar y int er net w ork ing enables net w or kinNet g work p r ofessionals AppleTalk Phy k Lay erst s, t echn ologies, an d devices used in t oday ' s net w ork ing t echnologies. Mast ersical t heand t erDa mtas,Lin con cep indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Net work Addr esses Com plet e AppleTalk w it h new an d Resolu u pdatt ion edPrchapt Address ot ocol er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Dat agram Deliv ery Pr oto col Ov erv iew net w or kin g p rof essionals, r egar dless of ex pert ise. AppleTalk Tran sport Lay er

Upperer er Protun ocols Reader s wAppleTalk ill obt ain a gLay reat der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Prot ocol it e v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on har dw ar e,AppleTalk pr ot ocols, andSuser Sum mar a b r oad r ang e ofy int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re Rev coniew cept comp Qu est ion s r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e For is also ext endion ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy More I nfo rmat syst em s,Cha prpter ovid in g a m or e sr ealist pict ur t he real- w or ld n et w or k ing en vir onm ent s in w hich 39 . I BM System Networ ic k Archit ecte ureofProt ocols pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Back groun d pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Tradit iona l SNA Environm ent s decisions for t h eir net w ork s. I BM Peer- Based Net work ing Basic I nf ormat ion Unit Form at Pat h I nf orm at ion Unit For mat Sum mar y Rev iew Qu est ion s

For More I nfo rmat ion Cha pter 40 . DECn et I n tr oduct ion DECn et Phase I V Digital Net work Arch itect u re DECn et / OSI Digit al Netwo rk Archit ect ure DECn et Media Access DECn et Rout ing

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DECn et End Com mu nicat ions Layer

I ndex

DECn et / OSI Transport Layer I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion DECn et Phase I V Upp er Lay ers By Cisco Systems, Inc. DECn et / OSI Upper Lay ers Sum mar y Pub lish er: Cisco Press Rev iew Qu est ion s Pub Dat e: Sep tem ber 1 1, 2 003 Part VI I . Rou t ing Prot ocols I SBN: 1- 58 705 -1 19 -2 Cha pter 41 . Border Gat eway Prot ocol Pages: 11 28 I n tr oduct ion BGP At tr ib ut es BGP Pat h Select ion Rev iew Qu est ion s For More I nfo rmat ion

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of 42t. t ingEnhaedg nced eI GRP essent ialCha anpter d cu t ech nologies. En han ced I GRP Capabilities and Att ribu t es Un derlyin g Pr ocesses an d Tech nologies

Con cise er vcept iewss of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Rou tinov g Con nov ice t o ex pert . En han ced I GRP Packet Ty pes

marer y s include cov erag e of im por t ant t opics like VoI P and EAP New Sum chapt Rev iew Qu est ion s

Cov erag e ofI nfo cut t ing For More rmat ionedge t echn ologies lik e opt ical n et wor k ing and st or age Cha pter 43 . I BM System s Networ k Archit ect ure Rout ing

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Back groun d

BMk in SNA Session Conn ect orHand s I n t ern et w Ior g Tech nologies book , Four t h Ed it ion , is a com pr ehensive refer ence t hat I BM SNA Tran smissio n Grou ps t o un derst and an d im plem en t cont em por ar y int er net w ork ing enables net w or kin g p r ofessionals I BM SNA Ex plicit an dt Virt uas, l Rout t echnologies. Mast er t he er m conescep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how o Ser incor I BM SNA Class tof vicepor at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e I w h new an dRout u pdat BMit SNA Subarea ing ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com e aning du p-tin t oI BM Ad van ced Peer-t o- Peerplet Net work Rou g d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Rev iew Qu est ion s

44ain . I n taer g io reat r Gat eway Protding ocol Reader sCha w illpterobt er unRout derinstg an

of LAN and WAN n et w or k ing, p ar t icu lar ly t h e groun d har dw ar e,Back pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on I GRPeProt Ch aract erist a b r oad r ang of ocol int egr al sy st ics em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re Sum conmar cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . y Cov erag e Rev is iew alsoQuext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy est ion s syst em s, For pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich More I nfo rmat ion pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Cha pter 45 . I n t er net Prot oco l Mu lticast pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Back groun d decisions for t h eir net w ork s. Mu ltica st Group Concept I P Mult icast Ad dresses I n tern et Group Man agem ent Prot ocol Mu ltica st in t he Lay er 2 Switching En viron men t Mu ltica st Dist ribut ion Trees

Mu ltica st Forwardin g Prot ocol- I ndepend en t Mu ltica st Mu ltipr oto col Border Gat eway Pr ot ocol Mu ltica st Source Discovery Prot ocol Rev iew Qu est ion s For More I nfo rmat ion Cha pter 46 . Net Ware Link - Serv ices Pr ot ocol

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Back groun d

I ndex

NLSP Hierar chical Rout ing I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion NLSP Operat ion By Cisco Systems, Inc. NLSP Hierar chical Addr essin g NLSP Hello Pack et s Pub lish er: Cisco Press Rev iew Qu est ion s Pub Dat e: Sep tem ber 1 1, 2 003 Cha pter 47 . Open Sh ort est Pat h First I SBN: 1- 58 705 -1 19 -2 Back groun d Pages: 11 28 Rou tin g Hierar chy SPF Algorit hm Packet Form at Addit io nal OSPF Feat ures Rev iew Qu est ion s

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of 48t.t ingOpenedg Sy steemt ech I n terco nnect ion Rout in g Prot ocols essent ialCha anpter d cu nologies. OSI Net work ing Term in ology Overv iew of OSI Rout ing Operat ion

Con cise ES- I Sov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . I S-I S

S LSP New I S-I chapt erProcessing s include cov erag e of im por t ant t opics like VoI P and EAP I DRP

Cov erag e of Sum mar y cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Rev iew Qu est ion s

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . For More I nfo rmat ion

Cha Rou tnologies in g I nf ormat ion Pro tocol , Four t h Ed it ion , is a com pr ehensive refer ence t hat I n t ern et w orpter k in49 g .Tech Hand book Back groun d enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Rou tinMast g Updat t echnologies. erest he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t oricincor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . RI P Rout ing Met Com plet e RIwPitStab h new an dures u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, ilit y Feat and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all RI P Timers net w or kin g p rof essionals, r egar dless of ex pert ise. Pack et Form at s

mar yain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Reader s wSum ill obt Qu est ionand s har dw ar e,Rev priew ot ocols, ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on For More ion sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions a b r oad r ang e of I nfo intrmat egr al t o en su re comprce r eh en sion r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Chacon ptercept 50 . Resou Reserv at ion and Prot ocol Cov erag e Back is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy groun d syst em s, RSVP pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Dat a Flows pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease RSVP Qualit y of Serv ice pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient RSVP Session St art u p decisions for t h eir net w ork s. RSVP Reserv at io n St y le RSVP Soft St at e I mplem en t at ion RSVP Operat ional Model RSVP Messag es RSVP Packet Form at

Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Cha pter 51 . Simp le Mult icast Rout ing Prot ocol I n tr oduct ion SMRP Mult icast Transport Serv ices SMRP Transact io n Example

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SMRP Pack et Forma t

I ndex

Rev iew Qu est ion s I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Part VI I I . Networ k Man agement By Cisco Systems, Inc. Cha pter 52 . Securit y Tech nologies Why I s Networ k Secu rit y I m port ant ? Pub lish er: Cisco Press Securit y Th reats Pub Dat e: Sep tem ber 1 1, 2 003 Securit y Policy I SBN: 1- 58 705 -1 19 -2 Def ense-in -Dept h Secu rity Solu t io n Pages: 11 28 Thr eat Mit igat ion Securit y Tools Sum mar y Rev iew Qu est ion s For More I nfo rmat ion

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Glossary essent ial an d cu tTerm t ing-s edg e t ech nologies. Cha pter 53 . Direct ory -Enabled Net wor kin g Object -Orient ed I nf orma tion Modelin g

Con cise ovI nt errod v iew s of echnories olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom A Brief uct ion t o tDirect nov ice t o ex pert . An Ov erv iew of DEN

DEN in Cisco ucte s of im por t ant t opics like VoI P and EAP New How chapt erI ss Used include covProd erag Sum mar y

Cov erag e Qu of est cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Rev iew ion s For More I nfo rmat ion

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Cha pter 54 . Net work Cachin g Tech nologies

n trkoduct I n t ern et w Ior in g ion Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Net work Caching enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing En surin g Fresh t m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t echnologies. Mast er Con t heten t er indu st ry . Lear n Qu how t os incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Rev iew est ion Com pletCha e wpter it h 55 new an d uNetwo pdatrkin edg chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, . St orage and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all What I s a SAN? net w or kin g p rof essionals, r egar dless of ex pert ise. Fibre Ch annel Prot ocol

iSCSIain Protaocol Reader s wThe ill obt g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e y har dw ar e,Sum pr mar ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Rev iew Qu int est ion a b r oad r ang e of egrs al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re For conMore ceptI nfo comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . rmat ion Cov eragCha e ispter also ext end ed ot only ent t o new n et wor k ing concep t s, but also t o old er , legacy 56 . I BM Net workn Managem syst em s, Back pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich groun d pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease I BM Net work -Ma nagemen t Fun ct ion al Areas pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient I BM Net work -Ma nagemen t Archit ect ures decisions for t h eir net w ork s. I BM Net work -Ma nagemen t Plat for ms Rev iew Qu est ion s Cha pter 57 . Rem ot e Mon itor in g Back groun d RMON Groups

Rev iew Qu est ion s Cha pter 58 . Simp le Net work Ma nagemen t Prot ocol SNMP Basic Co mpon en t s Basic SNMP Co mm ands SNMP Man agement I nf orm at ion Base SNMP and Dat a Represent at ion SNMP Ver sion 1

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SNMP Ver sion 2

I ndex

SNMP Ver sion 3 I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion SNMP Man agement By Cisco Systems, Inc. SNMP Reference: SNMP Message Form at s Sum mar y Pub lish er: Cisco Press Rev iew Qu est ion s Pub Dat e: Sep tem ber 1 1, 2 003 Cha pter 59 . Qualit y of Serv ice Net work ing I SBN: 1- 58 705 -1 19 -2 I n tr oduct ion Pages: 11 28 QoS Con cept s Basic QoS Arch it ect u re QoS I dent if icat io n a nd Marking QoS Wit hin a Sing le Net work Elem ent QoS Man agement

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of En d-t QoSedg Lev els essent ial an d ocuEnt tdinge t ech nologies. Modu lar QoS Comm and- Lin e I nt erf ace ( MQC) QoS Archit ect ures

Con cise ovion er -Ma v iew s of t echn Con gest nagemen t Toolsolog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Queue Managem ent ( Congest ion -Avo id ance To ols)

fic- Shaping and Policing Toolse of im por t ant t opics like VoI P and EAP New Traf chapt er s include cov erag Lin k Ef ficiency Mecha nism s

Cov erag e ofagement cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age QoS Man QoS on Et h er net

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Mu ltipr oto col Label Switch ing (MPLS): Allowing Flexible Traf fic En gineering

ToS I n t ern et w SNA or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat QoS f or kin Packet Voice enables net w or g pized r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing QoS f or St reamin g Video t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear Aut omnat how ed QoSt o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e Sum w itmar h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, y and speed, t h is book Rev iew Qu est ionis s a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. For More I nfo rmat ion

Part I X.ill Appendix Reader sw obt ain

a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e A. An swers Review est ion har dw arAppendix e, pr ot ocols, andt oser v icesQuinv olvs ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Cha pter a b r oad r ang e of1 int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re Cha conpter cept 2 comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e Cha is also pter 3 ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, Cha pr ovid pter in 4 g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Cha pter 5 pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Cha pter 6 decisions for t h eir net w ork s. Cha pter 7 Cha pter 8 Cha pter 9 Cha pter 10 Cha pter 11

Cha pter 12 Cha pter 13 Cha pter 14 Cha pter 15 Cha pter 16 Cha pter 17 Cha pter 18

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Cha pter 19

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Cha pter 20 I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Cha pter 21 By Cisco Systems, Inc. Cha pter 22 Cha pter 23 Pub lish er: Cisco Press Cha pter 24 Pub Dat e: Sep tem ber 1 1, 2 003 Cha pter 25 I SBN: 1- 58 705 -1 19 -2 Cha pter 26 Pages: 11 28 Cha pter 27 Cha pter 28 Cha pter 29 Cha pter 30 Cha pter 31

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Chadpter essent ial an cu 32 t t ing- edg e t ech nologies. Cha pter 33 Cha pter 34

Con cise ov er Cha pter 35 v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Cha pter 36

pter er 37s include cov erag e of im por t ant t opics like VoI P and EAP New Cha chapt Cha pter 38

Cov erag e of Cha pter 39 cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Cha pter 40

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Cha pter 41

I n t ern et w Cha or kpter in g 42 Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Cha pter 43 g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing enables net w or kin Cha pter 44 er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t echnologies. Mast indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Cha pter 45 Com plet e Cha w itpter h new 46 an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Chat h pter 47 net w or kin g p rof essionals, r egar dless of ex pert ise. Cha pter 48

49 a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Reader s wCha ill pter obt ain 50 har dw ar e,Cha prpter ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Cha pter a b r oad r ang e of51int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re Cha conpter cept 52 comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e Cha is also pter 53ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, Cha pr ovid pter in 54g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Cha pter 55 pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Cha pter 56 decisions for t h eir net w ork s. Cha pter 57 Cha pter 58 Cha pter 59 Appendix B. Early Tech nologies Token Ring/ I EEE 8 02 .5

Xer ox Net work Sy st ems Bany an VI NES I n dex

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Copyright Cop yr igh t © 200 4 Cisco Sy st ems, I n c. Cisco Pr ess log o is a t rad em ar k of Cisco Sy st em s, I nc. • Table of Content s •

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Four th Edit ion

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All rPub ightDat s e: reserv ed. No par t of t h is book m ay b e repr od uced or t r ansm it t ed in an y for m or b y any Sep tem ber 1 1, 2 003 m ean s, elect r onic or m ech anical, inclu ding ph ot ocopy in g or recor ding, or by an y inf orm at ion I SBN: 1- 58 705 -1 19 -2 st or age and r et r iev al syst em , w it hou t w r it t en p er m ission fr om t h e pu blish er , ex cept for t he Pages: 11 28 inclusion of b rief qu ot at ions in a r eview . Pr int ed in t h e Un it ed St at es of Am erica 1 2 3 4 5 6 7 8 9 0 First Prin t in g Sep t em ber 2 003 The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Lib rar yialofan Con gr tess Cat alogingin - Publicat ion Num ber: 61 947 205 1191 essent d cu t ingedg e t ech nologies.

Warning Con cise ovand er v iew sDisclaimer of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . This b ook is desig ned t o pr ov ide inf or mat ion ab out in t er net w or k in g t echn ologies. Ever y eff ort New m chapt cov eragas e of imppor and EAP has been ade er t o sminclude ake t his book com let et ant an dt opics accurlike at e VoI as pPossible, bu t n o w ar r ant y or fit n ess is im plied. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age The in for m at ion is p r ovided on an " as is" basis. The au t hor s, Cisco Pr ess, and Cisco Sy st em s, Aut h hored Sy st ldw ide leader in net w or king or it t he nh t err nespect et . I nc. shall ave by n eitCisco h er liab ilitems, y n orwror espon sib ilit y t o any person or fent y wI it t o any loss or d amag es arising fr om t h e inf orm at ion cont ained in t h is book or fr om t h e use of t he d iscs or I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat pr ogr am s t h at m ay accomp any it . enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing tThe echnologies. Mast er t heint er m s,b ook con cep t s, t echn ologies, d devices used in t oday 'tsh net ork ing op inions ex pr essed t his belong t o t he aut horan s and ar e not necessarily osewof Cisco indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Sy st em s, I nc. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

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Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e All er ms ed in t his ar eedkn owndam n t o be radt ech em ar k s or inf serv hav b eenon har tdw ar e,ment pr ot ion ocols, and serb vook icest hat inv olv . Fu enttal nology orice matmar ion kiss pr oveided app elyecapit Cisco Cisco em s, at t est t o ts,herev accur of ions t his a b rrop oadriat r ang of intalized. egr al sy st emPr s ess and or serv ices,Syst in clud ingI nc. detcannot ailed descr ipt ion iew acy quest inf a t errm in sion t h is book notand be ad regar ded as af fect in gf or t hefuvrtalid y udy of any t o orm en suatreion. conUse ceptofcomp eh en and r should et en t ion, dit ional r esou r ces heritst . tCov r adem ser vext iceend m ar eragark e isoralso edk .n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. At Cisco Press, our g oal is t o cr eat e in- d ep t h t echn ical book s of t he h ig hest qu alit y and v alu e. Each book is cr aft ed w it h car e an d p recision , und er g oin g r igor ous developm ent t hat in volv es t he un iq ue ex pert ise of m emb er s of t he pr of essional t echnical com m unit y .

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Cisco Repr esent at ive

Ant h ony Wolf en den

Cisco Pr ess Pr ogr am Man ager Pub lish er: Cisco Press

Sonia Torr es Ch avez

By Cisco Systems, Inc.

Pub Mar Dat e:k Sep Cisco et intem g ber 1 1, 2 003 I SBN: 158 705 Com m un icat ions -1 19 -2 Pages: 11 28 Man ager Scot t Miller

Cisco Mar k et in g Pr ogr am Man ager

Ed ie Quir oz

Ex ecu t ive Edit or Jim Schacht er le The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Man aging Edit or Pat r ick Kanouse essent ial an d cu t t ing- edg e t ech nologies. Dev elopm ent Edit or Jill Bat ist ick ConEdit ciseorov er v iew s of tMar echn Pr oject c olog Fow ies ler essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Cop y Edit or Gay le John son New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Aut h or Con t rib ut or s Tony Allen, Mat t Carling , Br adley Dun sm or e, Sach in Gupt a, Way ne Hick ey , Qiang Huan g, Mar celo Nobr ega, Tom Nosella, I v an Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Pepelnjak , D anny Rodr iguez, Mar cus Sit zm an, Srin iv as Vegesna h ored by Cisco Sy st w or ldw in net w orApcar king f ,orBrt he n t er n etor. e, Ven kat Tech Aut nical Ed it ors Brems, uce Alex andide er , leader Ton y Allen , Jeff ad IDunsm Kank ipat i, Saeed Sar d ar I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin unnet derst Team Coor dinat org p r ofessionals Tam m it oBar t and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Book Designer rod indu st ry . Lear n how t o incorGina por atRex e int erenet w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com e w itner h new an d u pdat Cov plet er Desig Loued isachapt Adairer s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Pr oduct ion Oct aldless Pu blish ingpert ise. net w or kin g pTeam rof essionals, r egar of ex I ndex er Tim Reader s w ill obt ain a g reat er unWr deright st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct at Corpor iv iteyHan e addqua im pr rt over e seff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions Cisco Sy stfor em ts, h eir I nc.net w ork s. 17 0 W est Tasm an Dr ive San Jose, CA 9 513 4- 17 06 USA w w w .cisco. com Tel: 40 8 526- 400 0

8 00 553 - NETS ( 638 7) Fax: 40 8 5 26- 4 100 Eur ope an H ea dq ua rt e rs Cisco Sy st em s I nt er nat ional BV Haar ler ber gpar k Haar ler ber gw eg 1 3- 19 11 01 CH Am st erd am • Table of Content s The Net h er lands • I ndex w w w - eu rop e. cisco. com I nt e rn et w or k ing Te chnologie s H a ndbook , Tel: 31 0 20 35 7 100 0 By Cisco Fax: 31Systems, 0 20 35Inc. 7 1 100

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Am Pub e rilish caer: s HCisco e adq ua rt e rs Press Cisco Sy st em s, I nc. Pub Dat e: Sep tem ber 1 1, 2 003 17 0 W est Tasm an Dr ive I SBN: 1- 58 705 -1 19 -2 San Jose, CA 9 513 4- 17 06 USA Pages: 11 28 w w w .cisco. com Tel: 40 8 526- 766 0 Fax: 40 8 5 27- 0 883 Asia ci fi H e adq e rs The u Pa pdat edc edit ion ua of rt t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Cisco em essentSy ialstan d s, cuItnc. t ing- edg e t ech nologies. Cap it al Tow er 16 8 Robinson Road Cont ocise # 22 - 01 # 2ov 9- er 01v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex Singap or e 068 912pert . w w w .cisco. com chapt er s 7include cov erag e of im por t ant t opics like VoI P and EAP Tel: +New 65 63 17 777 Fax: + 65 63 17 779 9 Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Cisco Sy st em s h as m ore t han 200 of fices in t h e follow ing cou nt r ies and r eg ion s. Addr esses, ored byan Cisco leader in net w or king ort et he ph oneAut nuhm bers, d f axSy nustmems, bers waroreldw listide ed on t h e Cisco.com W ebf si a t I n t er n et . w w w .cisco. com / go/ of fices. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net• wAu or kin g p r •ofessionals un derst an im plem cont em ar y int net w ork ing Ar gent ina st r alia Aust r ia • t oBelgiu m •and Br azil • dBulgar iaen • t Canad a por • Chile • erChina PRC • tColom echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork bia • Cost a Rica • Cr oat ia • Czech Repu blic D • en mar k • Dub ai, UAE • Fin lan d • Franing ce • indu st ry y. Lear n how • t oHong incor Kon por at int er or kin in t o•a ILAN/ WAN ir onm Ger man • Greece g eSAR • net Huwngar y g• t echn I ndia • olog I nd ies onesia r eland • Ienv sr ael • I tent aly. • Com plet w it h new d ubou pdat er s on secur it y•, est or age, opt ical w or k in g, scalabilit Japan • eKorea • Luan xem rged • chapt Malaysia • Mex ico Th Net h er land s • net New Zealand • Nor w y, ay • and speed, t h is book is a com plet e an d u pt od at e r ef er ence t o t he t op ics t hat are essen Peru • Philippines • Poland • Por t ug al • Puert o Ric o • Rom ania • Ru ssia • Saud i Ar abiat ial • t o all net wland or kin•g Sing p rof essionals, r egar of ex pert•ise. Scot apor e • Slov ak dless ia • Slov enia SoutAfr h ica • Spain • Sw eden • Sw it zerland • Taiw an • Thailand • Tur key • Uk r aine • Un it ed Kingd om • Un it ed St at es • Ven ezu ela • Viet nam • Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Zim babw e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r yr oad of 3int egr alSy syststems, em s Iand ices, cludving descrtipt s, rev Cop ighr tang © e200 Cisco n c. serv All lig ht s in r eser ed . det CCIailed P, CCSP, h eion Cisco Ariew row quest logo,ions the tCisco o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy Pow ered Net w or k m ar k, t he Cisco Sy st em s Ver ified log o, Cisco Un it y, Follow Me Brow .sing , Cov erag e is also extReadiness end ed n ot Scorecar only t o new n et k ingAcadem concepy, t s,and but Scr also o old , legacy Form Sh are, iQ Net d, Net w wor or king ipttSh ar eerare t r ademar k s syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm entest s inWw of Cisco Sy st em s, I nc. ; Ch angin g t h e Way We W ork , Live, Play , and Lear n, Th e Fast ayhich to pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease I ncr ease Your I n t ern et Quot ient , and iQuick St ud y ar e ser v ice m ar k s of Cisco Sy st em s, I nc.; and pr ct,ivASI it y ST, an dBPX, im pr Cat ov ealy effst iciency, ing tCCI he rE, eader m ake morCisco, e in t elligent , cost - eff icient Airodu onet , CCDA,help CCDP, CCNA, CCNP, t he Cisco Cer t ified decisions for t h eir net w ork s. I nt er net w ork Ex pert logo, Cisco I OS, t he Cisco I OS logo, Cisco Pr ess, Cisco Sy st ems, Cisco Sy st em s Cap it al, t he Cisco Sy st ems log o, Em p ower ing t he I nt er net Generat ion , En t er p rise/ Solv er , Et h er Ch annel, Et h er Sw it ch, Fast St ep, GigaSt ack , I nt er net Qu ot ien t , I OS, I P/ TV, iQ Ex pert ise, t he iQ logo, Light St ream , MGX, MI CA, t h e Net w ork ers log o, Net w ork Regist r ar, Packet , PI X, Post - Rout ing , Pr e- Rout ing , Rat eMUX, Regist r ar, Slid eCast , SMARTn et , St r at aView Plus, St r at m , Sw it chPr obe, TeleRou t er , Tran sPat h , and VCO ar e r eg ist er ed

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Icons Used in This Book Cisco uses t he follow in g st an dar d icons t o r epr esent diff erent net w or kin g d ev ices. You w ill encount er sever al of t h ese icons w it hin t h is book . •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Command Syntax Conventions The con vent ions used t o pr esent comm an d sy nt ax in t his b ook ar e t he sam e conv ent ions u sed in t he I OS Com m and Refer ence. The Com m and Ref er ence descr ibes t h ese conv en t ions as f ollow s: • •

Table of Content s I ndex

Vert ical b ars ( | ) separ at e alt er nat ive, m u t ually exclusive element s.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Squ Systems, are br ack Inc.et s

( [ ] ) ind icat e an op t ional element .

Br aces ( { } ) ind icat e a r eq uir ed choice.

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

Br aces w it hin br ack et s ( [ { } ] ) in dicat e a r equir ed ch oice w it hin an opt ional elem en t . I SBN: 1- 58 705 -1 19 -2

Bold Pages: in 11dicat 28 es com m ands and key w ord s t hat ar e ent er ed lit er ally as show n . I n conf ig ur at ion ex am ples and out p ut ( not general com m and syn t ax ) , bold indicat es com man ds t h at ar e m anu ally in put by t h e user ( such as a show com m and ) . I t alic in dicat es arg um en t s f or w hich y ou supply act u al v alu es. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction Net w ork ing and t h e I n t ern et hav e becom e one of t h e m ost inf lu en t ial f orces in our lives t od ay. They cont inu e t o ch ange t he w ay w e w or k, liv e, play , and lear n. I n less t h an t en y ear s, t h e ent ir e w or ld has e conn ect ed, mak ing it easy and inex pensiv e t o comm u nicat e arou nd t he • Tablebecom of Content s globe in st ant ly . Few wou ld ar g ue t hat t he I n t ern et has chan ged ev ery asp ect of our lives. I t ' s • I ndex im pr oved educat ion and m ade t h e ,wFour orld' infion or mat ion av ailable t o an y st udent any w her e, I nt e rn et w or k ing Te chnologie s H a ndbook th sEdit any t im e; it 's how w e com m unicat e w it h our r elat ives; it ' s how w e plan our v acat ions. We now By Cisco Systems, Inc. hav e t h e w orld and it s inf or m at ion at our f inger t ips—creat ing n ew oppor t un it ies f or ever y bu sin ess, gov ern ment , educat ional in st it u t ion, an d in divid ual. Pub lish er: Cisco Press

ThisPub b ook s to ou a f und am en t al un derst an ding of t he d iff er ent con cept s and Dat e:seek Sep tem berg1ive 1, 2y003 t echnologies in19t-2 h e field of n et wor k ing. This book is a comp r eh en siv e r ef erence t h at sur v ey s I SBN: 1- used 58 705 -1 a n umPages: ber of11dif fer en t n et w or k ing t ech nologies, pr ot ocols, an d p arad igm s; legacy t ech nologies 28 ar e included as w ell as t he m ost cu rr ent t ech nologies. I t is our hope at Cisco Pr ess t h at y ou w ill fin d t he f our t h ed it ion of t h is book cur r en t , r elev ant , an d u sef ul, w het her y ou ar e a n et w or k ing engineer or ot h er net w ork ing pr of essional or a bu siness decision - mak er . This book is also helpfu l if you sim ply w ant t o u nder st and m ore ab out t he I nt er net and t he t echnolog ies on w hich it r uns. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Objectives This b ook pr ov id es basic t ech nical infor m at ion about t he var ious t echn olog ies u sed in t he f ield of net w or kin g. I t is design ed f or use w it h ot her Cisco Pr ess book s and as a st an dalone r efer en ce t ool. •

Table of Content s

•This b ook is not I ndexint ended t o p r ovide all possib le in for m at ion on t he t echnologies cover ed; r at h er , Iitntseeks e rn et wtor ing chnologie s H a ndbook , Fourhth ion in g t he m ost r elev ant and im por t ant det ails of o kpr ovTeide a general over view ig Edit hlight each t echnolog y. By Cisco Systems, Inc. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Updates to the Fourth Edition For t he publicat ion of t he f our t h ed it ion of t h is book , w e hav e ad ded n ew ch apt er s on opt ical net w or kin g, Voice ov er I P ( VoI P) , DPT/ SRT, EAP, st or age n et w or k ing, QoS, and I OS. Th er e ar e also m any u pdat es t o exist ing chapt er s, and t he most relevan t an d cur r ent in for m at ion h as been •included w here Table of Content s appr opr iat e. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Audience The I n t er net w or k in g Techn olog ies Han dbook is wr it t en for an yon e w ho wan t s t o und er st and int er net w ork ing . We an t icipat e t hat t he inf or mat ion in t his b ook w ill help y ou assess t he app licabilit y of specif ic t ech nologies in you r net w or king env ir onm en t s and giv e y ou a basic •un derst an ding Table of tofheContent m an ys int ern et wor k ing t ech nologies. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Organization This b ook is or ganized in t o t he follow ing nine sect ions: P ar t I : Table I nt r oduct of Content ions t o I nt e rne t w ork i ng— Prov ides int r odu ct ory in for m at ion ab out t he basic concept I ndex s and t echnolog ies of n et w or k ing, in clu ding LAN and WAN t echnologies, Cisco t wTe are, b rid ging and sw, Four it ch in t echn I nt e rn IetOS w orsof k ing chnologie s H a ndbook th gEdit ion ologies, r out in g pr ot ocols, an d n et wor k m anagem ent . By Cisco Systems, Inc. • •

P ar t I I : LAN Prot ocols— Cov er s LAN pr ot ocols and t heir t echnolog ies. Pub lish er: Cisco Press Pub P Dat ar te:I Sep I I :tem W ber AN1 1, Technol 2 003 ogi es—

Discusses WAN t echnolog ies, includin g Fr am e Relay, HSSI I SDN, PPP, I SBN:, 158 705 -1 19 -2 SMD S, dialup , SDLC, X. 25, and VPNs. Pages: 11 28

P ar t I V : Mu lt i se rv i ce A cce ss Te chnol ogie s— Prov ides ov er v iew infor m at ion on access net w or kin g t echn olog ies, includ in g voice/ dat a in t eg r at ion , w ir eless, D SL, cable, opt ical, VoI P, DPT/ SRT, and EAP. P ar t V : Bri dgi ng an d Sw it chi ng— Discusses br idging an d sw it ching t ech nologies, The uincludin pdat ed g edit ionspof t he bbrest - selling allone net ork ing r ef erence cover age of t r an arent idgin g, m ix edin- media br w idging , sour ce- r outperov br ides idging , LAN essentsw ialit ch anin d gcuand t t ingedg e tATM, ech nologies. VLANs, MPLS, and d at a link sw it ching. P ar t V I : N e t w ork P rot ocol s— Cov er s n et w or k in g pr ot ocols, in clud ing OSI P, I P, I Pv6 , Con cisee,ovAppleTalk, er v iew s of ItBM echnSNA, olog ies t ial. t o n et wor k ing pr ofession als at all lev els, f rom Net War andessen DECnet nov ice t o ex pert . P ar t V I I : Rout i ng P rot ocols— Prov ides ov er v iew infor m at ion on rou t ing pr ot ocols, New chapt er s include cov erag e of imSNA, por t ant t opics VoI includin g BGP, Enh anced I GRP, I BM I GRP, I nt like er net PrPotand ocolEAP Mu lt icast , Net War e Lin kServ ices, OSPF, OSI RP, r out ing inf or mat ion , r esour ce r eser vat ion , and SMRP. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age P ar t V I I I : N e t w ork M a nag em e nt — Discusses secur it y t echnologies, dir ect or y - enabled Aut h ored st ems, wt or ldw ide leader w or orking t he. I n t er n et . net w or kin by g, nCisco et w orSy k caching ech nologies, andinstnet orag e king net w for I n t ernAp et w or kdix in geTech book Ed it ion com ehensive t hat of pen s: — nologies These ApHand pendix es ,prFour ov idteh answ er s, is t o ar ev iewprqu est ions refer and ence discu ssion enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing early t echn olog ies. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Acknowledgments and Contributors Cisco Pr ess w ou ld lik e t o ex pr ess it s deep est gr at it ude t o t h e t alen t ed p eop le wh o cont r ibu t ed t o t he four t h edit ion of t his book . W it h out t heir help and ex per t ise, w e w ou ld n ot h ave b een able t o pu it ion Than k sy ou t o all w ho helped w r it e and edit t he chap t er s in t h is new edit ion. • blish t h is ed Table of. Content I• n alp habet ical or der , t he cont rib ut or s ar e as f ollow s: I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Bru ce A le xa nd er is t he t echnical m ar ket ing m anag er for t h e Cisco Sy st em s Wir eless By Inc. NetCisco w orkSystems, ing Business Un it . He join ed Cisco as a r esult of Cisco' s acquisit ion of Air onet Wireless Com m un icat ions, w h er e he w as t he d ir ect or of t ech nical supp ort . He has w or k ed in t he RF t echnology Pub lish er: Cisco ar ea Press f or m or e t han 27 y ears, an d h e has w or k ed w it h RF WAN t ech nology f or 17 y earPub s. Dat Alexan has1 1,w 2or003 k ed ex t en siv ely wit h t h e RF eng in eer ing gr oup at Tex lon, in bot h e: Sepder tem ber har dw ar e an1-d58sof w19 are, I SBN: 705t-1 -2 w her e he was t he senior inst r uct or f or nat ional ed ucat ion cent er s. Add it ion ally , h e has h eld an am at eu r r adio licen se sin ce 1 978 . He is a cof ound er of Amer it r on Pages: 11 28 Am at eur Rad io Com pan y. Alex and er at t en ded Ak r on Un iv er sit y , w her e he m aj or ed in com pu t er pr ogr am m ing and business adm inist r at ion. Tony A ll en, CD ( Canadian Decorat ion ) , is a n et wor k consult in g eng ineer w or k ing for Cisco Sy st em s on t he Amer icas I n t er nat ion al Adv anced Ser v ices Team in Toron t o, Can ada. For t h e last Ther uypdat ion of t heser b est - selling all- inone ork ing r ef erence p rovent ides age eof t heir fou ear s,edheedit has helped v ice p rov ider cust omnet erswplan, d esign, imp lem , ancover d operat essent an dt ions. cu t t ingedgeej oin t ech nologies. net w orial k solu Befor ing Cisco, he spent 17 year s w it h t he Canadian Milit ar y, w or k ing in a v ar iet y of t elecom mu nicat ion s engineer in g and main t en ance posit ions. He cur r en t ly specializes in t he d esign, en gineering , and t est ing of VoI P, opt ical w ir eless t ech nologies, and br oadban d Con er va iew t echnah, olog t ial ten o :n et wor pr ofession els, f rom net w or ks.cise He ov has wifse,ofDebor anies d tessen wo childr Sar a, k5ing , and Alex andals er , at 3 . all Hislev hob bies nov ice t o ex pert . include keeping abr east of t he lat est t echn olog y, gar dening , ph ysical fit n ess, and spendin g qu alit y t ime wit h his fam ily . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Ma t t Ca rl in g is a net w or k consult ing engineer in t he Ad van ced Ser v ices Gr ou p at Cisco Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Sy st em s. Du ring t h e past t hr ee year s at Cisco, h e has w or k ed closely w it h man y ser v ice pr ovider cust om erhsored t o prby ov ide netSy w or kin g op t imizat ion solut ions, echnolog Aut Cisco st ems, w or ldw ide leader in nettw or king f yorand t he ser I n tverices n et .deploy m en t , and im plement at ion of Cisco b est pr act ices net w or kin g t echn iq ues. He has m or e t han 1 2 y ears of exp er ience wor knologies ing. He has bachelor eg ree in comp utrefer er engin ing and I n t ern et w orin k inngetTech Handa book , Fouroft hengineerin Ed it ion , isgad com pr ehensive enceeer t hat a g r aduat e d iplom a in m anagem en t scien ces, bot h f rom t he Univ er sit y of Can berr a, Au st r alia. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Bra u nsm or e tis a newpor p rod in net st r uct for h e Adv anced oup env at Cisco indudl stey ry . DLear n how o incor at euct int er w ororkin g ttechn olog ies inSer t o avices LAN/Gr WAN ir onm ent . Sy st em s in Resear ch Tr iang le Park , N. C. He holds t he Cisco CCNP, CCD P, CCSI , an CSS- 1 y, Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, dscalabilit cer t ifspeed, icat ions, asbook w ell is asaan MCSE+ nt er rom . I nt oh is rent h e desig and t h is com plet e Ian d unet p- tfod at Microsoft e r ef er ence t hecur t op ics posit t hat ion, are essen t ialns t o all net w or k t opolog ies f or new cour ses in h is gr oup and t r ains inst r uct or s t o t each t h e cou rses. net w or kin g p rof essionals, r egar dless of ex pert ise. Add it ion ally , h e desig ns n et w or k s t hat allow t he rem ot e and secu re dow nloading of t h ese cour ses. He in SS7 I nder t er st conn ect solut ion and s, WAN com nicat ions, Cisco Reader sw ill specializes obt ain a g reat er un an ding of LAN WAN n etmu w or k ing, p arand t icu lar ly t hsecu e rit y pr odu har dwct ars.e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Sa Gupt is acomp pr odu ct en m sion anager h et Cisco Catad alydit st ional 65 00.r esou He holds a CCI cerst t ifudy icat.ion in t o chin en su re conacept r eh andf or r ett en ion, and r ces f or fu rtEher Rou t ing and Sw it ch in g. Bef ore h is cur rent posit ion, h e w or ked for Cisco as a t echnical m Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacyar ket ing engineer t he Iinntgeranet ologicies d ur ivision, w hrealer e he OSonm sof tent w ars ein w hich syst em s, in pr ovid m orTechn e r ealist pict e of t he w orfocused ld n et won or kCisco ing enI vir tpr echnologies. Bef or e t hat , Gup t a w as a cu st omer sup por t eng ineer at Cisco. He has a mease ast er ' s of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr degr ee in elect rical eng in eer ing fr om St an for d Un iver sit y . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. W ay ne H i ck e y h as m or e t han 20 y ear s of t elecom m un icat ions and comp ut er dat a exp er ience, includin g SONET, SDH, D WDM, I P, ATM, Fram e, HFC, v oice, video, an d SSEM. He is a pr odu ct m anager f or t h e Opt ical Technical Business Unit at Cisco Sy st em s. Pr ev iously, he spent 19 y ear s w or king f or Aliant Telecom ( NBTel) , t he t h ir d - lar g est t elecomm u nicat ion s pr ov id er in Canada, w her e he f ocu sed on t r ansm ission n et wor k d esign and t h e ev aluat ion of emer ging access an d t r ansm ission t echn ologies. Hick ey h as coaut hor ed and aut h ored sev eral paper s on Polarizat ion

Mod e Disp er sion ( PMD) and long- h aul t r an sm ission syst em s. He has ap plied f or sev eral pat ent s on pr im ary an d secondar y p roj ect s for h yb rid fib er coax ial ( HFC) . Qi an g H u ang , CCI E No. 493 7, is a cu st omer sup por t eng in eer in t he Cisco VPN and Net w or k Secu rit y Gr oups. He h as ex t ensiv e kn ow ledg e in man y secur it y pr od uct s and t echnologies, and he h as ser v ed as t he t echnical lead f or h is gr oup for t he past sev er al year s. Huang has mu lt ip le CCI E cert if icat ion s, in clu ding I SP Dial, Rout ing and Sw it ching, and Secur it y . He h as a m ast er' s degr ee in elect rical an d com pu t er en gineer ing f rom Color ado St at e Un iv er sit y . •

Table of Content s

•Ve nk at Ka nk I ndex i pa t i h as been a soft w ar e dev elop ment m anager at Cisco Sy st em s f or six year s. IHis nt e rn et w k ingspans Te chnologie s H raang ndbook Edit ion exp erort ise a w ide e of, Four t echthnologies,

in clu ding SNA pr ot ocols and secu rit y and netCisco By w or kSystems, per for mInc. ance. Bef or e joinin g Cisco, h e w ork ed f or Bay Net w or ks. Kan kipat i has a m ast er ' s degr ee in com pu t er science fr om t h e Un iver sit y of Massachu set t s, a mast er 's d eg r ee in comPub put erer:apCisco plicat ion s fr om t h e Un iver sit y of Madr as, and a b ach elor of scien ce degr ee fr om t h e lish Press Univer sit y of Bomb ay, I n dia. Pub Dat e: Sep tem ber 1 1, 2 003 SBN: 1- 58 705 -1 19 -2 Ma r ce Ilo N obr eg a, CCI E No. 806 9, is a senior n et wor k consult in g eng ineer at Cisco Sy st em s in Pages: 11 28 t he Adv anced Serv ices Gr oup, wh ich supp or t s Am er icas I nt ern at ional Th eat er . He h as w ork ed w it h desig n d ep loy m ent , ad min ist r at ion, and t r oubleshoot ing of larg e ser v ice pr ovider n et w or k s since 199 4. He h as been w it h Cisco Sy st em s since 20 00. His focus h as been on cor e I P and r out ing pr ot ocols, net w or k m anagem en t , I P Telephon y, and, m ost recen t ly, I P call cent er s. Nobr ega h as a b achelor of science degr ee in elect r onic eng ineer ing and a mast er 's d eg ree in com er ed science f r om icia Univ ersidad Catnet olica Univer y in Riopde o, Brage azil.of The put u pdat edit ion of tPont he bifest - selling all- in-eone w ork ing rsit ef erence rovJaneir ides cover essent ial an d cu t t ing- edg e t ech nologies. Tom N ose ll a, CCI E No. 139 5, is senior m anager of t echnical m ar k et in g in t he St orag e Tech nology Grou p at Cisco Sy st em s. He and h is t eam cr eat e, v alid at e, and pr om ot e Cisco st or age Connet cise w or ovker in vgiew d esign s of st echn and olog soluties ions essen f or Cisco's t ial t o nent et wor er pr k ing ise and pr ofession ser v iceals p rov at all iderlev cust els,om f rom ers. Befor nov e j oin iceing t o Cisco, ex perth. e w as dir ect or of en gineering at Bell Canad a in Resid en t ial and Com m ercial I nt er net Ser v ices, w here he led a t eam of sen ior en gineers. He h as a b ach elor of Newinchapt s include cov e off rom im por t ant t opics like VoI engineer g anderman agem en t erag d eg ree McMast er Univ ersit yP in and Ont EAP ario, Canada.

of, cut edge echn ologies e opt n et wor k ing or age I v an Cov Peperag el njea k CCIt ing E No. 135t4, has mor e lik t han t enical y ears of ex per and iencestin designing , inst allin g, t r oub leshoot ing , and oper at ing lar ge ser v ice pr ovider an d en t er pr ise WAN an d LAN n et w or k s. He Autt echn h ored by Cisco st ems, w or ldw ide leader in ion nets.w or f orart he t erof n etNI . L' s Serv ice is chief ologies advSy isor at NI L Dat a Comm u nicat Heking is t he chitI n ect Pr ovid er Acad em y pr og ram , h e is one of t h e ar ch it ect s of t he Serv ice Pr ovider cur r icu lum at ICisco n t ernSy et wstor k in Techhe nologies Handdeveloper book , Four Ederal it ionser , isv a prider ehensive refer ence em s,gand is t he lead oft hsev icecom p rov cour ses t hat covt hat er MPLS, enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net orkCisco ing BGP, an d I P QoS. Pepelnj ak is one of t h e Cisco r out ing aut hor it ies in Eu rop e. He w rot e wt he tPr echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ess b ook EI GRP Net w ork D esign Solut ions and cow r ot e t he Cisco Pr ess b ook MPLS and VPNing indu ry . uLear Ar ch st it ect res. n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, h gue is book com e an it d yu eng p- t oat einr eft he er ence t op t hat essen t ial t o all D a nny Rodtri z is is aa net w orplet k secur indeer Securt oit yt he Con suics lt ing Serare v ices netganizat w or kinion g p at rof Cisco essionals, r egar dless pert or Syst em s, w hereofh eexper forise. m s secur it y p ost u re assessm ent s an d secur it y design rev iew s f or For t une 5 00 comp anies. He is also r espon sible f or t h e t r ain ing and Reader w ill obt reatsecur er unitder st an ding n et whor lar ly t hhee has dev elopsment of ain t he aotgher y engin eer s of in LAN his grand oupWAN . Du ring is kt ing, en ur pe ar w titicu h Cisco, har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion pr ov ided on been an edu cat ion specialist in t he Secur it y Tr aining depar t m ent in t h e Cisco I nt erisnet Lear ning a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions and Solut ion s Gr oup ( I LSG) . He aut hor ed t he Cisco I nt ru sion Det ect ion cour ses and con t r ib ut ed tt o reercon cept r eh en sion andit yr etcour en t ion, ad dit r esou r ces f or on fu rtsecur her st o en labsuex cises f orcomp Cisco' s cor e secur ses. and He also h ional as t aug ht cou rses it yudy t o . Cisco Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy engineer s, Cisco lear ning an d Chann el Part n er s, an d end user s. Rodr iguez w as also a k ey syst s, or pr ovid a m orcer e rt if ealist ic pict ur eam of . t He he realor ldt ificat n et wions or k ing vir onm in w hich contem r ibut t o t hine gCCSP icat ion pr ogr h old sw cer as aenCCDA anent d as CSS1. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr iv itrd y an im pr ovked e effas iciency, help ing r eader m ake e Speed in t elligent costg- eff icient Saodu e edctSa ar dh as w or a d ev elopm en tt he eng ineer in t h e mor Hig hSwit, chin Grou p at decisions for t h eir net w ork s. Cisco Sy st em s f or m ore t han t w o y ears. He has w or ked ext ensiv ely w it h t est in g and resolving cont r ol an d d at a p lan e issu es f or Cisco I OS on t he Cisco Cat aly st 6 000 ser ies r elat ing t o I Pv4 , I Pv6 , MPLS, QoS, an d m u lt icast r out in g and har dw ar e for w ar ding on a v ar iet y of LAN an d WAN m odules. Ma r cus Sit z m a n, CCI E No. 900 4, is a net w ork secur it y engineer w it h Cisco Syst em s. He has

m or e t han six year s of exp er ience in t he net w or kin g f ield . Since join in g Cisco in 20 00, he h as cont inu ed t o focus on secu rit y t echn ologies and pr oduct s. He cur r ent ly pr ov ides secur it y post u re assessment s and secur it y consult ing t o Cisco cu st omer s. He has t rain ed ot her Cisco eng ineer s in t he area of secur it y and w as t he t echn ical sp eak er at Cisco' s Net wor k ers Conv en t ion. Al an Trou p is a t echnical w r it er for t h e Cisco MDS 900 0 fam ily of st or ag e sw it ches. He w as pr eviou sly a t ech nical pub licat ions man ager in one of Cisco's op t ical sw it ch div isions. He h as a bachelor of ar t s degr ee in Eng lish fr om San Jose St at e Univ ersit y . •

Table of Content s

•Sr ini v as V e ge I ndex sna, CCI E No. 139 9, is m anag er of sof t w are developm ent in Cor e I P Eng in eer ing Iat nt eCisco rn et w or k ing Tes. chnologie H a ndbook th Edit Syst em Bef ores his cur r en, tFour posit ion,ion he

w as a con su lt ing en gineer and m anager of Cisco's By Cisco Systems, Ser vice Pr Inc. ov id er Consult ing Ser vices. His ex per t ise is in gener al I P n et wor k ing, wit h a special focus on I P an d I P QoS. I n his m or e t han eight y ear s at Cisco, Veg esna has w or k ed w it h a larPub gelishnum ber Press of serv ice pr ov id er and en t erp rise cust om er s, h elpin g t h em desig n, im plement , er: Cisco andPub t r oub leshoot larg e- scale I P net w or k s. He has a mast er of science d eg ree f r om Ar izon a St at e Dat e: Sep tem ber 1 1, 2 003 Univer sit y and an MBA f rom Sant a Clar a Univer sit y. I SBN: 1- 58 705 -1 19 -2

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Third Edition Contributors Con t rib ut or s t o t he Th ir d Ed it ion ( in alphab et ical or der ) ar e Marc Bresnik er , Ger r y Bur gess, Dav e Bust er , Kev in Ham ilt on , Br ian Ju nnila, An dr ew Kessler , William Lan e, Kev in Mahler, Er ick Mar , Kevin Mousseau, Jim O'Shea, W illiam Par k hur st , Ed ie Quir oz, Neil Reid, Fr ank Riv est , Mar k •Spor t ack , John Table Content St rofassn er , san d Nat alie Tim m s. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

First Edition Contributors Pr incip al aut hor s of t he f irst ed it ion of t h is book w er e Merilee Ford , H. Kim Lew , St ev e Span ier , and Tim St ev en son . •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Part I: Introduction to Internetworking Ch apt er 1 I n t er net w or k in g Basics • •

Ch apt er 2 I n t rod uct ion t o LAN Pr ot ocols Table of Content s

Ch apt er 3 I n t rod uct ion t o WAN Techn ologies I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ch apt er 4 I n t rod uct ion t o Cisco I OS Soft w ar e

By Cisco Systems, Inc.

Ch apt er 5 Br idg ing and Sw it ch in g Basics

Cher: aptCisco er 6Press Rout ing Pub lish

Basics

Pub Ch Datapt e: Sep ber 1w1,or 2k 003 er tem 7 Net Man agement

Basics

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 1. Internetworking Basics Obj e ct i ve s • •

Table of Content s

Lear n wh at m ak es up an int ern et wor k . I ndex

I nt e rn Lear et w ornk ing H a ndbook Four th Edit ion t heTebchnologie asics of st he OSI m,odel. By Cisco Systems, Inc.

Lear n t he d if fer en ces b et w een con nect ion - orient ed and connect ionless ser vices. Pub lish er: Cisco Press

Lear n about t he d iff er ent t yp es of addr esses used in an int er net w ork .

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 58 705 -1 19 -2con t rol and err or - check ing basics. Lear n 1about flow Pages: 11 28

This chap t er w ork s w it h t he next six ch apt ers t o act as a f ound at ion f or t h e t ech nology discussion s t hat follow . I n t his chapt er , som e fu ndam ent al con cept s and t erm s u sed in t he evolv ing langu age of int er net w or king ar e add r essed . I n t he sam e w ay t hat t his b ook pr ov id es a fou ndat ion f or un derst and ing m odern net w or k in g, t h is chapt er sum m ar izes som e com mon t hem es pr esent ed t hr oug hout t he rem ainder of t h is book . Topics include flow cont r ol, er ror The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of check ing , and m ult iplexin g, b ut t his chapt er f ocuses m ainly on m app in g t he Op en Sy st em essent ial an d cu t t ing- edg e t ech nologies. I nt er con nect ion ( OSI ) m odel t o n et wor k ing/ in t er n et w or k in g fun ct ion s, and also sum m arizing t h e gener al nat ur e of addr essing schemes w it hin t h e con t ext of t he OSI m odel. The OSI mod el r ep r esent s t h eovbuildin s f orolog int ies er net w orkt ial s. Under anding t hofession e concepals t ual h elpfsrom you Con cise er v iewgs boflock t echn essen t o n et st wor k ing pr at m allodel lev els, un derst an d t h e comp lex p ieces t hat m ake up an in t er n et w or k . nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

What Is an Internetwork? An int ern et wor k is a collect ion of in div id ual n et w or k s, con nect ed by in t erm ediat e n et w or k ing dev ices, t hat fu nct ions as a single lar ge n et w or k . I nt er net w ork ing r ef ers t o t h e indu st r y , pr odu ct s, and pr ocedu r es t hat m eet t h e challen ge of creat ing an d ad min ist er ing int ern et wor k s. •Figur e 1- 1 illust Table Content r atofes somes diff er ent kin ds of net w or k t echnologies t hat can be int er connect ed by •r out er s and ot I ndex her n et w or k ing devices t o cr eat e an int ern et wor k . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu e er:1 -Cisco 1 . Di ff e r en t N et w or k Tech nol ogie s Ca n Be Con ne ct ed t o Cr e at e Pubrlish Press a n I n t e r ne t w or k Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . History of Com plet e w it hInternetworking new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net wfor kinnet g pwrof The ir st or essionals, ks wer e t imr egar e- sh dless aring of n etex w pert or k sise. t hat used m ainf r ames an d at t ach ed t er m in als. Such en vir onm ent s wer e im plem ent ed by b ot h I BM's Sy st em s Net w or k Ar ch it ect ur e ( SNA) and Reader w illwobt a gitreat ere.un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Digit al' ss net or kain ar ch ect ur har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e wofork intsegr al sy st s and serv ices, ailed descr ipt ionm s, ult rev quest Localarea net ( LANs) evem olved ar ound t he in PCclud r eving olu tdet ion. LANs en abled ipiew le user s inions a tr oelat enivsuely re sm conall cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy g eog rap hical ar ea t o ex ch ange files and m essages, as w ell as access shar ed. Cov erag e is alsoasext end n ot only r esour ces such file seredv er s an d prt o in new t ers. n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Widearea netoper w orkat s e. ( WANs) in t ergu conn ect LANs w itim h geogr aphically dispersed t o creat pr of essionals Tools and id elines f or opt izing syst em per for m anceuser w ills incr ease e connect ivit Som e pr of ov t hee eff t ech nologies used or connect ing LANs e T1, T3 , ATM, I SDN, pr odu ct iv it y .an d im iciency, help ing tf he r eader m ake morin e clud in t elligent , cost - eff icient ADSL, Fr am , r adio decisions fore t Relay h eir net w ork link s. s, and ot h er s. New m et hods of conn ect ing d isper sed LANs are app ear ing ever y day . Today , h ig h- speed LANs and sw it ch ed int er net w ork s ar e b ecom ing w id ely u sed , larg ely b ecause t hey op er at e at v er y h ig h sp eeds an d su ppor t su ch hig h- ban dw idt h app licat ions as mu lt imedia and v ideocon fer en cing .

I nt er net w ork ing evolv ed as a solut ion t o t h r ee k ey pr oblem s: isolat ed LANs, du plicat ion of r esour ces, and a lack of net w or k m anagem en t . I solat ed LANs mad e elect r onic comm u nicat ion bet w een dif fer en t of fices or depar t m ent s im possible. Dup licat ion of resour ces m eant t hat t he sam e har dw ar e and soft w ar e had t o be sup plied t o each off ice or depar t m ent , as d id separ at e supp ort st aff . This lack of net w or k m anag em ent meant t hat no cen t ralized met h od of m anag ing and t r oub leshoot ing n et w or k s exist ed. •

Table of Content s

• Internetworking I ndex Challenges I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

I mCisco plemSystems, ent ing aInc. fu nct ional int er net w or k is no sim ple t ask . Man y challen ges m ust b e faced, By esp ecially in t he ar eas of con nect iv it y , r eliabilit y , net w or k m anagem ent , an d f lex ibilit y . Each ar eaPubislish k ey in estPress ablish ing an ef ficient and eff ect iv e int er net w or k. er: Cisco Pub Dat e: Sep tem ber 1 1, 2 003

The ch alleng e w hen conn ect ing v ar iou s syst em s is t o su ppor t com m un icat ion am ong dispar at e I SBN: 1- 58 705erent -1 19 -2 sit es, f or exam ple, m ay u se d iff er ent t yp es of media operat in g at v ar ying t echnologies. Diff Pages: 11ay 28 even inclu de d if fer ent t yp es of sy st em s t h at n eed t o com m unicat e. speed s, or m Becau se com pan ies r ely heav ily on d at a com mu nicat ion, int er net w or ks mu st pr ov ide a cer t ain level of r eliab ilit y . Th is is an u npr edict able w or ld, so m an y larg e int ern et wor k s include r ed und ancy t o allow for com m unicat ion ev en w h en pr oblem s occu r . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Fur t her mor e, net w or k m anag em ent mu st pr ov ide cent r alized supp ort and t r oub leshoot ing essent ial an d cu t t ing- edg e t ech nologies. capabilit ies in an int er net w or k. Conf igur at ion, secur it y, perf or man ce, an d ot her issues m ust be adequ at ely ad dr essed f or t h e int ern et wor k t o fu nct ion sm oot h ly . Secur it y w it hin an in t er n et w or k is essent y vpeople ink ofolog neties w oressen k secur rom t hek ing p er spect iv e ofals p rot he pr iv at e Conial. ciseMan ov er iew s oft ht echn t ialit tyof n et wor pr ofession atect alling levtels, f rom net w or k fr omt oou sid e .at t ack s. How ev er , it is ju st as im por t ant t o pr ot ect t he n et wor k f r om nov ice ext pert int er nal at t ack s, esp ecially because m ost secur it y br eaches come fr om inside. Net w ork s m ust also be secur ed er sos tinclude hat t he cov int er nalenof et wor k cann b e used ool t EAP o at t ack ot h er ex t ern al New chapt erag im por t ant ot t opics like as VoIaPt and sit es. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Ear ly in t he y ear 20 00, m an y m ajor w eb sit es w er e t he v ict im s of d ist r ibu t ed d en ial of ser v ice Autat h ored byThese Cisco at Syt acks st ems, ldw ide leader in net or king t eratneetn. et w or k s ( DD OS) t ack s. w erweorpossible because a gw r eat numf borert he of pI nr iv cur r en t ly con nect ed w it h t he I nt er net wer e not pr oper ly secur ed. Th ese pr iv at e net w or ks w er e I n t ernas et w or k infor g Tech nologies used t ools t he at t ack ers.Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast t hewtor erld m s, cep t s, echn ologies, devices in t oday net w ork ing Becau se not hing inert his is con st agnan t , tint er net w ork san m dust be f lexused ible enoug h t 'os chang ew it h indu st ry . and Lears.n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . new d em Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Open System Interconnection Reference Model The Op en Sy st em I nt er connect ion ( OSI ) refer ence m odel d escr ibes how in for m at ion f r om a soft w ar e app licat ion in one com put er m ov es t hr ough a net w ork mediu m t o a soft w ar e app licat ion in an ot her com put er . The OSI r ef erence m odel is a concep t ual m od el com posed of •sev en lay er s,Table Content s eachofsp ecify ing par t icular n et w or k f unct ions. Th e m odel w as dev elop ed by t he •I nt er nat ionalI ndex Or ganizat ion for St andar dizat ion ( I SO) in 1 984 , and it is n ow considered t he Ipr ntim e rnary et w or k ing ect Te chnologie s H a ndbook th Edit archit ur al m odel f or int ,erFour comp ut erioncom mu nicat ions. The OSI m odel div ides t he t ask s invCisco olvedSystems, w it h mInc. ov ing inf orm at ion bet w een net w or ked comp ut er s int o sev en sm aller , m or e By m anageable t ask g r oups. A t ask or gr oup of t ask s is t hen assign ed t o each of t he sev en OSI lay er s. Each layer is r eason ably self - cont ained so t hat t he t ask s assigned t o each lay er can b e Pub lish er: Cisco Press im plem ent ed independ en t ly. This enables t he solut ion s off ered by on e layer t o be u pdat ed Pub Dat e: Sep tem ber 1 1, 2 003 w it hout adv er sely aff ect in g t h e ot her lay ers. Th e follow ing list det ails t he seven layer s of t he I SBN: 1- 58 705 -1 19 -2 Op en Sy st em I n t er connect ion ( OSI ) r efer en ce m od el: Pages: 11 28

Lay er 7— Applicat ion Lay er 6— Presen t at ion The uLay pdat edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of ered5— Session essent ial an d cu t t ing- edg e t ech nologies. Lay er 4— Tran sp ort Con cise ovNet er vwiew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Lay er 3— or k nov ice t o ex pert . Lay er 2— Dat a link New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Lay er 1— Phy sical Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat NO TE enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t het ot er m s, con t echn ologies, devices t odayseem ' s nettwo ork ing A h andy way r emem bercep t h tes,sev en lay ers is an t hed sent enceused " All in people indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env onm need d at a p rocessing . " The beginnin g let t er of each w or d cor r esp onds t o a ir lay er . ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin gApplicat p rof essionals, All— ion lay err egar dless of ex pert ise. Reader s w ill obt ain a tgatreat People— Presen ionerlayun erder st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang of int egr alersy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Seem — eSession lay t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy To— Tran sp ext ort end lay er syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals Need — Net oper w or at k e. lay Tools er and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Dat a— a link ers. decisions for Dat t h eir net wlay ork Pr ocessin g— Phy sical lay er Figur e 1- 2 illust r at es t he sev en - layer OSI refer ence m odel.

Figu r e 1 - 2 . The O SI Ref e r en ce M ode l Con t ai ns Se ve n I n de pen de nt La ye r s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Characteristics of the New chapt er s include covOSI erag eLayers of im por t ant

t opics like VoI P and EAP

Cov cutt ht ing edge t echn e opt n et or age The sev enerag lay eerof s of e OSI r efer en ceologies m od ellik can be ical divid edwor intkoing t w oand catst egor ies: upp er lay er s and low er layer s. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The up per lay er s of t he OSI m od el deal w it h applicat ion issues and gener ally are im plem en t ed I n t ern w orwkar in g Hand , Four t hion Ed itlayer ion , , isisaclosest com pr ehensive only inetsoft e.Tech The nologies h ighest lay er , book t he app licat t o t he en drefer u serence . Botthhat users enables net wion or kin g p rpofessionals o un d eimapp plem enions t cont em por y int and app licat layer rocesses intt er actderst w it hand softan w ar licat t hat conar t ain a er net w ork ing t echnologies. Mast er ponent t he t er .mThe s, con t s, per t echn ologies, anetdim devices in t oday ' s net ing e com mu nicat ion s com t ercep m up layer is som es usedused t o r efer t o any laywerork abov indu st ry .layer Lear nin how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . anot h er t he OSI m odel. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and lower speed, a com plet eh an d u pt oe r ef ert ence t o tThe he tphy op ics t hat essen t ialdat t oaall The layt heriss book of t h eisOSI m odel andle d at a dt rat anspor issues. sical layare er and t he net wlay or kin p rof dless ise. link er g are imessionals, plem en t edr egar in har dw arofe ex anpert d sof t w are. Th e lowest lay er, t he p hy sical lay er , is closest t o t he p hy sical n et wor k m edium ( t he n et w or k cabling , for ex am ple) and is r esp onsible for Reader w ill obt ain reat untder ding. of LAN and WAN n et w or k ing, p ar t icu lar ly t h e act uallys placing inforamg at ioneron he st man edium har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad e ofr at int al division sy st em s bet andw een serv tices, in cludan ing deter ailed ipt ion s, rev iew quest ions Figur e 1-r 3ang illust esegr t he he u pper d low OSIdescr lay ers. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals operr at and f or ye optrim systUem ance w illerincr Figu e e.1 -Tools 3 . Tw o gu Seidtelines s of La s izing M a ke p tper heforOmSI Lay s ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Protocols

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The OSI m odel pr ov ides a concept u al fr am ewor k f or com mu nicat ion b et w een com pu t er s, b ut t he m odel it self is n ot a m et h od of com m unicat ion. Act u al comm u nicat ion is m ade possible b y using com mu nicat ocols. t heolog conties ex tessen of d at a nt o et n wet orwor k in g, a pr ocol is als a foratmall al lev set els, of r fules Con ciseion ov perrot v iew s of Itnechn t ial k ing prot ofession rom and conv ent ions h at .g over ns h ow com put er s exchan ge inf or mat ion ov er a net w or k m edium . A nov ice t o extpert pr ot ocol im plem en t s t he f un ct ion s of one or m or e of t h e OSI lay er s. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP A w ide var iet y of comm un icat ion pr ot ocols exist . Som e of t h ese p rot ocols includ e LAN p r ot ocols, WAN Cov p r oterag ocols, e of n et cut w or t ing k pr edge ot ocols, t echnand ologies r out ing lik epopt rot ocols. ical n etLAN worpr k ing ot ocols and op st or erage at e at t h e phy sical and dat a link lay er s of t h e OSI m odel an d define com m unicat ion over t h e v arious LAN m edia. Aut ored op byerCisco w ort hr ldw w ormod kingel f or I n t eercom n et . m un icat ion WAN pr othocols at e atSyt hsteems, lowest eeide layleader ers of in t henet OSI andt he defin ov er t he v ar iou s w ide- ar ea m ed ia. Rou t in g pr ot ocols ar e n et wor k lay er pr ot ocols t hat ar e t ern etsib w or in gex Tech nologies Hand Four t h Ed is at hat comt he pr ehensive refer ence tthe hatp rop er rI nespon le kfor ch angin g in for m atbook ion b, et w een rouittion er s, so r out er s can select enables p ric. ofessionals t owun an ar d im en t cont emerpor arer y int erocols net w ork ing pat h f or net netw wor orkin k t rgaff Finally , net orderst k pr otand ocols e tplem he v ariou s upp - lay pr ot t hat t echnologies. Mast erocol t he suit t er m conycep t s,ocols t echnr ely ologies, an ds devices t oday ' s net ork ing exist in a given pr ot e.s,Man pr ot on ot her f or operused at ion.inFor exam p le,w m any st rypr . Lear n how incor int er net w or kin gget echn olog t owaeen LAN/ WAN ir onm ent . rindu out ing ot ocols uset on et w orpor k pat roteocols t o ex chan inf orm at ies ion in bet r out er s.env This concept Com it h new d er u pdat ed chapt er ist s on secur st orndat age, opt w or in g, scalabilit y, of buplet ild inegwupon t hean lay s already in ex ence is tithye, fou ion ofical t henet OSI mkodel. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

OSI Model and Between Reader s w ill obt ain aCommunication g reat er un der st an ding of LAN andSystems WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a r oadatrion angbeing e of int al sy st em s and serv ices, in clud ailed descrutipt rev iew I nfborm t regr ansfer red fr om a soft w ar e app licating ion det in on e comp erion sy s, st em t o a quest sof t wions are tapp o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ion licat ion in an ot her m ust pass t hr oug h t he OSI lay ers. For ex am ple, if a soft w ar e app licat Cov erag e is extorm endat edion n ot o new worwkar ing concep s, but also t o old in Syst em A also has inf t oonly t ran tsmit t o naetsoft e app licattion in Sy st em B, er t h ,e legacy applicat ion syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm hich pr ogr am in Sy st em A w ill pass it s inf or mat ion t o t he ap plicat ion lay er ( Lay er 7) ofent Sy sstin emwA. Th e pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease app licat ion layer t h en passes t he in for m at ion t o t he pr esent at ion layer ( Layer 6 ) , w hich relay s pr ctaivtitoyt han im pr ovlay e eff help ing t heon r eader in t elligent cost t heodu dat e dsession er iciency, ( Lay er 5) , an d so d ow n m t oake t h emor phyesical lay er (, Lay er- eff 1) icient . At t h e decisions for t h eir net w ork s. ph ysical layer , t h e infor m at ion is placed on t he phy sical n et wor k m edium and is sent acr oss t he m ed ium t o Syst em B. The ph ysical layer of Sy st em B r emov es t he in for m at ion fr om t h e phy sical m ed ium , and t h en it s p hy sical lay er passes t h e infor m at ion up t o t he dat a link lay er ( Lay er 2) , w hich passes it t o t h e net w or k layer ( Layer 3 ) , and so on , unt il it r each es t he app licat ion layer ( Lay er 7) of Sy st em B. Finally , t he applicat ion lay er of Syst em B passes t h e inf orm at ion t o t he r ecipient applicat ion pr ogr am t o com plet e t h e comm un icat ion pr ocess.

Interaction Between OSI Model Layers A g iven layer in t he OSI m odel gener ally com m un icat es w it h t hr ee ot her OSI lay er s: t he lay er dir ect ly ab ove it , t he lay er dir ect ly b elow it , and it s peer layer in ot her n et wor k ed com put er syst em s. The d at a link lay er in Sy st em A, f or ex am ple, com mu nicat es wit h t h e net w or k layer of Sy st em A, t he p hy sical lay er of Syst em A, an d t he dat a link lay er in Sy st em B. Figur e 1- 4 • Table of Content s illust rat es t his exam ple. •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 1 - 4 . OSI M ode l Lay er s Com m un icat e w i t h O t h er Lay e r s Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

OSI Layer Services Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et wlay or kerin g Tech nologies Hand bookh,erFour h Ed a com refer enceby t hat On e OSI com m un icat es w it h anot lay ter t o it mion ak ,e is use of t hpre ehensive ser v ices pr ov ided t he enableslay neterw.or t o by un derst andt an t cont OSI em por int ermnet orkeing second Thkin eg serp vr ofessionals ices p rov ided adj acen layderim s hplem elp aengiven layar ery com unw icat wit h t echnologies. t er s, con t s, Th t echn an d devices used in tinoday s net ork ing it s peer lay er Mast in ot herert he com pumt er sy stcep ems. r ee ologies, b asic element s ar e inv olv ed lay 'er serw vices: st ryvice . Lear n how o incor atider, e int er nettwhe orser kin vice g t echn olog poin ies int t(oSAP) a LAN/ tindu he ser user , t he tser vice por pr ov and access . WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, speed, t h tis, tbook isvaicecom plet u p- lay t o- er d att e r efrer t he t op ics t hat essen tOSI ial t o all Iand n t his cont ex he ser u ser ise t an he dOSI hat eqence uest st oser v ices f rom an are ad jacent neter w or kinegser p rof essionals, lay . Th v ice p rov iderr egar is t hedless OSI of layex erpert t hatise. pr ov ides ser v ices t o ser v ice u ser s. OSI lay er s can pr ovide ser vices t o m u lt ip le ser v ice u ser s. The SAP is a concept ual locat ion at wh ich one OSI Reader s wrill aint he a gser reat er un st an LAN lay er can eqobt uest vices ofder anot h erding OSIoflay er . and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad e ofr at int al sy st emtshrand serv ices, in clud ingatdet ipt ion s, arev iewlayquest Figur e 1-r 5ang illust esegr how t hese ee elem en t s int er act t heailed n et wdescr or k and d at link ers. ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals and gu elines f or ropt izingSAPs syst emI nt perefor ance ease Figu r e 1 - 5oper . Seatre.viTools ce User s, idPr ovi de s, im a nd r amct at wt ill h eincr Ne t w or k pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient a nd Da t a Li nk Lay e r s decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

OSI Model Layers and Information Exchange Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The sev laypert ers .use v arious for m s of cont r ol inf orm at ion t o com m un icat e w it h t h eir p eer noveniceOSI t o ex lay er s in ot her com put er sy st em s. This cont r ol in for m at ion con sist s of specif ic r eq uest s and inst r uct ions t h aterars einclude ex ch anged betew of eenimpeer OSI t opics lay er s.like VoI P and EAP New chapt cov erag por t ant Con t rol pically t akt echn es one of t wo m s: h ead s and ailers. ar e Covinfor eragmeatofion cutt yt ing edge ologies lik for e opt ical n eter wor k ingt rand st orHeaders age pr epended t o d at a t hat h as been p assed dow n fr om u pper lay er s. Tr ailer s ar e ap pended t o d at a t hat has d own r om upp s. An OSI layer n otf or r equir o natett ach a h ead er or Aut hbeen ored passed by Cisco Sy stfems, w orer ldwlayer ide leader in net w oris king t he ed I n tter . a t railer t o dat a f r om up per layer s. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Headers, t r ailers, d at a ar e r elat concept dd epim enplem ding en ont tcont he lay t hat zeswt ork he ing enables net w or kinan g pdr ofessionals t o ive un derst ands,an emerpor ar y analy int er net inf orm at ion unMast it . Atert he layer , tf s, or texam ple, an inf at ion un it consist s of' sanet Lay t echnologies. t henet t erwmors,k con cep echn ologies, anorm d devices used in t oday wer ork3ing header d d at At t o heincor d at apor link howwev t he in for ies m atin ion dow nenv by irt honm e ent . indu st ryan . Lear n a. how at elay inter, er net orer kin, gallt echn olog t o passed a LAN/ WAN net wplet or k elayer t he Lay header and er t hseon datsecur a) isittyr eat as dat a.ical net w or k in g, scalabilit y, Com w it h ( new an deru 3pdat ed chapt , sted or age, opt and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Inet n ot herkinwgorpds, t he d at a p rort iondless of anofinf ion un it at a giv en OSI layer p ot en t ially can w or rof essionals, egar exorm pertatise. cont ain header s, t railer s, and dat a fr om all t h e high er lay er s. This is k now n as encapsulat ion . Figur e 16 illshobt ows h e header and at a f rom oneand lay WAN er aren en lat ed o tlar helyh tead Reader sw ainhow a gtreat er un der st and ding of LAN et wcap or ksuing, p arint t icu h e er of thar he dw next low lay er .and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on ar e, prest ot ocols, a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst Figu emrs,e pr 1 ovid - 6 . inHe g aade m orresr ealist a nd icDa pict t aur Can e of t he BerealEnwca orpsu ld n etla wtor ekding D ur en vir i ng onm I nf entor s in mwat hich ion pr of essionals oper at e. Tools and gu id elinesExcha f or optng im izing syst em per for m ance w ill incr ease e pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Information Exchange Process The in for m at ion ex change pr ocess occu r s bet w een peer OSI lay er s. Each lay er in t h e sou r ce The u pdat hemat b est all-and in- one w orkining erence p rovsy ides cover age ofan d syst em ad ed ds edit contion r ol of inf tor ion- selling t o dat a, eachnet layer t her efdest in at ion st em analyzes essent ial an d cu t t ingedg e t ech nologies. r em ov es t he cont rol in for m at ion fr om t h at dat a. I f Syst em A has dat a f rom a soft w ar e app licat ion t o send t o Syst em B, t h e dat a is passed t o t he Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom app licat ion layer . The applicat ion lay er in Sy st em A t h en com m unicat es any cont r ol in for m at ion nov ice t o ex pert . r eq uir ed by t he ap plicat ion lay er in Sy st em B by p r ep en ding a h ead er t o t h e dat a. Th e r esult in g inf orm at ion un it ( a header and t he dat a) is passed t o t he pr esen t at ion lay er, w hich p repend s it s New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP ow n header cont aining cont r ol in for m at ion in t en ded f or t h e pr esent at ion lay er in Sy st em B. The inf ormCov at ion une itofgrcut owt sing in edge size as each lay er p en ds owwor n header ( anstd, som e cases, a erag t echn ologies likr ep e opt icalit sn et k ing and or in age t r ailer ) t hat con t ains cont r ol in for m at ion t o be u sed by it s peer lay er in Syst em B. At t he p hy sical lay er ,Aut t h eh ored ent ir ebyinfor m at ion unit is placed ont o t h e in netnet w ork m. t he I n t er n et . Cisco Sy st ems, w or ldw ide leader w ormediu king f or The p hy sical lay in Sy st em BHand r eceiv es ,t he inftor d pprasses it t o refer t he dat a lin k layer . I n t ern et w or k in g er Tech nologies book Four h mat Ed it ion ion ,un is ita an com ehensive ence t hat The d at a link lay er in Syst em B t hen r eads t he cont r ol inf or mat ion cont ain ed in t he h ead er ing enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork pr epended by t h e dat a link lay er in Sy st em A. The h ead er is t hen r em oved, and t he r em ain t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w orkder ingof tindu he in for m at ion unit is passed t o t he net w or k lay er . Each lay er perf or ms t he sam e act ions: The st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . lay erplet r eads t he header ited s peer layer st rsecur ips it itof passes t he net r emainin for m at iony, Com e w it h new an df rom u pdat chapt er s ,on y ,f, stand or age, opt ical w or k ingg,inscalabilit un it t o t he n ex t highest lay er. Aft er t h e applicat ion lay er per for m s t hese act ions, t he dat at ial is t o all and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen passed t o t he r ecip ien t soft war e ap plicat ion in Syst em B, in exact ly t h e for m in w hich it w as net w or kin g p rof essionals, r egar dless of ex pert ise. t r ansm it t ed b y t he ap plicat ion in Syst em A. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e Physical of int egr al syLayer st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions OSI Model t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy The p hys,sical lay in ergdefines e elect ical,urmeechanical, al,w and f unct spent ecificat ions syst em pr ovid a m or et hr ealist icr pict of t he real-prwoced or ld ur n et or k ing enional vir onm s in w hichf or act ivat in g, m aint ainin g, an d d eact iv at ing t he p hy sical link b et ween com m un icat ing n et w or k pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease syst emcts.iv it Phy sical lay ecif icat ionshelp define eristmics such volt ag e lev of pr odu y an d im prer ov sp e eff iciency, ing tchar he ract eader ake moras e in t elligent , els, cost t- im effing icient vdecisions olt age chang es, p hy sical d at a r at es, m axim um t ran smission d ist an ces, and ph ysical connect or s. for t h eir net w ork s. Phy sical lay er im plement at ion s can b e cat eg or ized as eit her LAN or WAN specificat ions. Figur e 17 illust r at es some com m on LAN an d WAN ph ysical layer im plem en t at ions.

Figu r e 1 - 7 . Ph y si cal Lay er I m pl em e n t at ion s Ca n Be LAN or W AN

Specif ica t i ons

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

OSI Con Model Data Layer cise ov er v iewLink s of t echn olog ies essen t ial t o n et wor k ing

pr ofession als at all lev els, f rom nov ice t o ex pert . The d at a link lay er pr ov ides r eliable t r ansit of dat a acr oss a p hy sical n et w or k link . Dif fer en t d at a New chapt er s ions include cov d erag oft im P anderEAP link lay er sp ecificat d ef ine if fereen n etpor w ort ant k ant opics d p rotlike ocolVoI ch aract ist ics, including p hy sical add ressin g, n et w or k t op olog y, er r or n ot if icat ion , seq uencing of fr am es, an d flow cont r ol. Ph ysical Cov erag e opposed of cut t ingt oedge echn ologies opt ical nhet wor k ing or age add ressin g ( as n et wt or k add r essinlikg)e defines ow dev icesand ar estadd ressed at t he dat a link lay er . Net w or k t opolog y con sist s of t h e dat a lin k layer specificat ions t h at of t en d ef ine how Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . dev ices ar e t o be ph ysically con nect ed, su ch as in a bus or a r ing t opology . Er ror not ificat ion alert s upp er - lay er pr ot ocols t hat a t r ansm ission er r or has occur r ed, and t h e seq uencin g of dat a I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat fr am es r eor der s f ram es t hat ar e t r ansm it t ed ou t of sequence. Fin ally , f low cont r ol m oder at es t he enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t r ansm ission of dat a so t hat t he r eceiv ing device is not ov er w helm ed w it h m ore t raf fic t han it can t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing han dle at one t im e. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, The I n st it u t e of Elect rical an d Elect r onics En gineer s ( I EEE) has sub divid ed t he dat a lin k layer int o and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all t w o su blayer s: Log ical Link Cont r ol ( LLC) and Media Access Cont r ol ( MAC) . Figur e 1- 8 illust r at es net w or kin g p rof essionals, r egar dless of ex pert ise. t he I EEE sublay er s of t h e dat a lin k layer . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Figu r ecomp 1 - 8r .ehThe Daand t a rLin La and ye r ad Cont ai ns Twr ces o Subl er st s udy . t o en su re con cept en sion et enkt ion, dit ional r esou f or fuay rt her Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The Logical Lin k Con t rol ( LLC) su blayer of t h e dat a lin k layer m anag es com m un icat ions bet w een dev ices ov er a single link of a net w or k. LLC is d ef ined in t he I EEE 802 . 2 specificat ion an d supp ort s bot h connect ionless an d con nect ion - orient ed ser v ices u sed by h ig her- lay er pr ot ocols. I EEE 8 02. 2 defines a num b er of f ield s in d at a link lay er fr am es t hat enable m ult iple h igher - layer pr ot ocols o sh areion a single dat aalllink The net Media t r ol p( rov MAC) sucover blayerage of of the The u pdatted edit of t he p b hy estsical - selling in-. one w orkAccess ing r efCon erence ides dat a link ages ocol access t o t he p hy sical n et w or k m edium . Th e I EEE MAC essent ial lay an dercuman t t ingedgpr e ot t ech nologies. specif icat ion def in es MAC addr esses, w hich enab le mu lt iple dev ices t o uniqu ely id en t if y one anot h er at t h e dat a lin k layer . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

OSI New Model chaptNetwork er s include Layer cov erag e of im por t ant

t opics like VoI P and EAP

erag e of t ing edge t echn lik e opt icaldnifet ing tand st or age The nCov et wor k lay er cut defines t h e net w orologies k add ress, w hich ferwor s frkom he MAC add ress. Som e net w or k layer im plem en t at ions, such as t he I nt er net Prot ocol ( I P) , define net w ork ad dr esses in a Cisco st ems, werm or ldw ide syst leader inically net w by or king or ting he tI hn et ersou n etr .ce n et wor k w ay tAut hat hrored out e by select ion Sy can b e det ined em at com fpar add ress w it h t he d est inat ion net w or k add ress and app lying t h e su bnet m ask . Because t his lay er Idefin n t erneset twhe or logical k in g Tech Ed tithis ionlay , isera tcom prer ehensive refer t hat netnologies w or k layHand out , rbook out er, sFour cant huse o d et m ine how t o ence f or war d enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing pack et s. Because of t his, m uch of t he design an d conf igur at ion w ork for in t er net w or k s happ en s tat echnologies. t er m. s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Lay er 3, t h eMast net er w ort he k layer indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all OSI Model Transport Layer net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s sp w ill ain g reatserd at unader st ant he ding of LANlayer and an WAN n et went or ks ing, ar at icu ly t h The t ran ortobt lay er aaccept f rom session d segm t h e pdat forlart ran speort har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov across t he net w or k. Generally , t he t r anspor t lay er is respon sible f or m ak in g su re t hat t heided dat aonis a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions deliver ed er ror - f r ee an d in t h e pr oper seq uence. Flow con t r ol gener ally occur s at t he t ran sp ort tlay o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . er . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst s, rprolovid in g aesmdor pict urbet e ofw een t he realw or so ld nt hat et w or k ing en viritonm in w hich Flowem cont m anag atea rt ealist r an smicission dev ices t he t r ansm t ing ent devs ice d oes pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease not sen d m or e dat a t h an t h e r eceiving d ev ice can pr ocess. Mult iplexing enables d at a f rom pr odu ct iv it y an dions im prt oovbe e eff iciency, help r eader akelink mor e int ual t elligent , cost - eff icient sev er al applicat t ran sm it t ed onting o at he single p hy m sical . Vir cir cuit s ar e est ab lish ed , decisions for t h eir net w ork s. m aint ained, and t er m inat ed by t h e t r anspor t lay er. Er r or ch eck ing inv olves cr eat in g v ar ious m ech anism s f or det ect ing t r ansmission er r ors, w h ile er r or r ecov er y inv olv es act ing , such as r eq uest in g t hat dat a be r et ran sm it t ed, t o r esolv e any er r ors t hat occur . The t ran sp ort pr ot ocols used on t h e I nt er net ar e TCP and UDP.

OSI Model Session Layer The session layer est ablishes, man ages, and t erm inat es com m unicat ion session s. Com m un icat ion sessions consist of ser v ice r equ est s an d ser vice r espon ses t h at occur b et ween app licat ions locat ed in d if fer ent n et wor k d ev ices. Th ese r equest s and r esp onses are coor dinat ed by p r ot ocols im plem en t ed at t he session lay er . Som e ex amp les of session- lay er imp lem ent at ion s include Zon e I nf orm at ion Pr ot ocol ( ZI P) , t he Ap pleTalk pr ot ocol t hat coord inat es t he n am e • Table of Content s bind ing pr ocess; an d Session Con t r ol Pr ot ocol ( SCP) , t he DECnet Phase I V session lay er • I ndex pr ot ocol. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

OSI Model Presentation Layer Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

The p r esent at ion layer p rov ides a var iet y of cod ing and conv er sion f un ct ion s t hat ar e applied t o I SBN: 1- 58 705 -1 19 -2 app licat ion layer d at a. These fu nct ions ensur e t h at inf or mat ion sent f r om t he applicat ion lay er of one syPages: st em 11 w28 ould be r ead able by t he app licat ion layer of an ot her syst em . Som e exam ples of pr esent at ion lay er coding and conv er sion schem es in clu de com mon d at a r epr esent at ion for m at s, conv er sion of ch aract er r ep r esent at ion for m at s, com mon dat a com pr ession schem es, an d com mon dat a encr yp t ion schem es. Com on dat repr at ion f or mat s, or he one u se net of st ag e, sou nd,ides an d cover videoage for m The umpdat ed aedit ionesen of tthe b est - selling all-t inwan orkdar ingd rim ef erence p rov ofat s, enable t h e int er ch ange of ap plicat ion d at a bet w een d if fer ent t yp es of com pu t er sy st ems. essent ial an d cu t t ing- edg e t ech nologies. Con ver sion schemes ar e used t o ex ch ange in for m at ion w it h syst em s by u sin g d iff er ent t ex t and dat a r ep resent at ions, such as EBCDI C an d ASCI I . St andar d dat a com pr ession sch em es enable dat a tCon hat cise is com ov er prvessed iew s of at ttechn he sour ologce iesdev essen ice tt oialbet opr n et operly wor k ing d ecom pr ofession pr essedals at at t h ealldest levin els, at ion. f rom St andnov ardice d att a o encr ex pert yp.t ion schem es en able dat a en cry pt ed at t he sour ce device t o be p rop er ly decipher ed at t he d est inat ion . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Pr esent at ion lay er im plem en t at ions ar e n ot t y pically associat ed w it h a p ar t icu lar pr ot ocol st ack . erag e ofn cut t ing edge ologies e opt ical worMot k ing Som eCov w ellk now st andar ds fort echn v ideo in clud lik e Quick Timen et and ionand Pictstuor reage Ex pert s Gr oup ( MPEG) . Qu ick Tim e is an Apple Comp ut er specif icat ion f or vid eo and aud io, and MPEG is a Autdhfored st ems,and w orcoding ldw ide. leader in net w or king f or t he I n t er n et . st andar or vidby eoCisco com pSy ression I n t ern orw k in g kn Tech Hand book Fourst hare EdGr it ion , is aI nt com pr ange ehensive ence hat t Am ongettwhe ellownologies n g r aphic im age f or, mat aphics er ch For mrefer at ( GI F) , tJoin enables net w or kinerg t ps rGrou ofessionals t o, un and an imeplem cont por.arGI y Fintiseranet w ork Phot og r aphic Exp p ( JPEG) anderst d Tagged I mdag File en Fort m at (em TI FF) st an daring d f or t echnologies. Mastcoding er t he gr t eraph m s,ic con cepes. t s,JPEG t echnisologies, d devices used t oday s an netdar w ork ing com pr essing and im ag an ot herancom pr ession an dincod in g ' st d for indu stic ry imag . Leares, n how o FF incor int der cod net w or kin g at t echn iesicinimag t o a es. LAN/ WAN env ir onm ent . gr aph an d tTI is por a stat anedar ing for m f or olog gr aph Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

OSI Model Application Layer

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har e, prion ot ocols, serOSI v ices inv olv ed . Fu ent t ech orsmat ionbot is hprt ov Thedw apar plicat lay er and is t he layer closest t ondam t h e en d aluser , wnology hich minf ean t hat h eided OSI on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions app licat ion layer an d t h e user int er act dir ect ly w it h t he sof t w ar e applicat ion. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . This lay er intalso er actext s wit soft waronly e apt plicat s wor t hatk im ent tas, com unicat ingercomp onent . Cov erag e is endh ed n ot o newion n et ingplem concep but m also t o old , legacy Such applicat ioninpr ou ic t sid e tur hee scope t h ewOSI odwel. plicat iononm layent er fun s syst em s, pr ovid g ogr a mam or es rfall ealist pict of t he of realor ld m n et or kAp ing en vir s inctwion hich tpr y pically in clu de ident ying com unicat ion fpar nerim s, izing det ersyst m ining r esour ceance av ailab y , ease an d of essionals oper at e.ifTools andmgu id elines or topt em per for m w ill ilit incr syn ch rctonizing ion. pr odu iv it y ancom d immprun ovicat e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. When ident if ying com mu nicat ion p ar t ners, t he app licat ion layer d et er m in es t he ident it y and av ailab ilit y of com m unicat ion par t ner s for an ap plicat ion w it h dat a t o t r an sm it . Wh en det er min in g r esour ce availabilit y , t he ap plicat ion lay er m ust decide w het h er suf ficient n et wor k r esour ces for t he r equest ed com m unicat ion ex ist . I n sy nchr onizing com mu nicat ion, all com mu nicat ion b et w een ap plicat ion s r eq uir es coop er at ion t hat is m anaged by t h e applicat ion

lay er . Som e exam ples of app licat ion layer im plem en t at ions includ e Teln et , File Tr ansfer Pr ot ocol ( FTP) , and Sim ple Mail Tr ansf er Prot ocol ( SMTP) .

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Table of Content s

•

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Information Formats The d at a an d con t rol infor m at ion t hat is t r ansm it t ed t h rou gh int ern et wor k s t ak es a v ar iet y of for m s. The t er m s used t o r efer t o t hese in for m at ion for m at s ar e not used consist en t ly in t he int er net w ork ing ind ust r y but somet im es ar e used int er chang eab ly . Comm on inf orm at ion f orm at s •include fr am es, Table of Content s ag ram s, seg m en t s, m essages, cells, and dat a unit s. p ack et s, dat •

I ndex

IAntf er rn et w or ing in Tefor chnologie ndbook , Four th rce Edit an iond d est inat ion ar e dat a link lay er en t it ies. A fr am e ame is kan m at ions Hu anit wh ose sou is com posed of t he dat a lin k layer header ( an d possib ly a t r ailer ) and upp er - lay er dat a. Th e By Cisco Systems, Inc. header an d t r ailer cont ain con t r ol inf orm at ion int ended for t he d at a link lay er en t it y in t he dest inat ion sy st em. Dat a fr om up per - lay er ent it ies is encapsulat ed in t he dat a lin k layer header Pub lish er: Cisco Press and t r ailer . Figur e 1- 9 illust r at es t he basic com pon en t s of a dat a link lay er f ram e. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 1 - 9 . Da t a f r om Upp er - La ye r En t it ie s M ak e s Up t he D at a Lin k La ye r Fr am e The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP erag oforcut t ing t echn e opt ical n et wor age ent it ies. A p ack et ApackCov et is an einf m at ion edge u nit w h oseologies sour celik and d est inat ion arkeing netand w or st k or layer is com posed of t he net w ork lay er header ( an d p ossibly a t r ailer ) an d upper - lay er d at a. The Autan h ored by Cisco Sy st ems, ororm ldwat ide in net king I ner t eren n et header d t r ailer cont ain con t r ol winf ionleader int ended forw or t he n etfworort khelay t it. y in t he dest inat ion sy st em. Dat a fr om up per - lay er ent it ies is encapsulat ed in t he net w ork lay er header I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat and t r ailer . Figur e 1- 1 0 illust r at es t he basic com pon en t s of a net w ork lay er pack et . enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Figu r e 1 - 1 0 . Th r ee Ba si c Com pon en t s M a k e Up a N et w or k Lay er Packe t and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The t er m dat agr am u sually ref er s t o an in for m at ion unit w hose sou r ce an d dest in at ion ar e net w or k layer ent it ies t h at u se conn ect ionless net w or k ser v ice. The t er m segm ent u sually ref er s t o an in for m at ion unit w hose sou r ce an d dest in at ion ar e t r anspor t lay er ent it ies.

Am essage is an inf or m at ion u nit w h ose sour ce and d est inat ion ent it ies ex ist ab ove t he net w or k lay er ( oft en at t h e applicat ion lay er ) . Acell is an inf or m at ion u nit of a fix ed size w hose sour ce and dest inat ion are dat a lin k layer ent it ies. Cells ar e u sed in sw it ched en vir onm ent s, such as Asyn ch ron ous Tr ansfer Mode ( ATM) and Sw it ched Mult im eg abit D at a Ser vice ( SMDS) net w or ks. A cell is com posed of t he header an d pay load. Th e header cont ains con t r ol inf orm at ion int ended for t he d est inat ion dat a link lay er ent it y an d is t yp ically 5 by t es long. Th e pay load con t ains up per - lay er dat a t hat is encapsulat ed • Table of Content s in t he cell header and is t y pically 48 by t es long. •

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I nt e rn et w or H adndbook , Four th Edit ion The leng t hk ing of tTe hechnologie header san t he pay load fields

alw ays are t he sam e for each cell. Figur e 1- 1 1

By Ciscos Systems, depict t h e comp Inc. onent s of a t y pical cell.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Figu r e 1 - 1 1 . Tw o Com p on e nt s M ak e Up a Typi ca l Ce ll

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Dat a unit is a gener ic t erm t hat ref er s t o a v ar iet y of in for m at ion u nit s. Som e com mon dat a un it s I n teern ar seretvw ice ordk at in g a Tech u nit snologies ( SDUs) ,Hand pr ot ocol bookd, at Four a u nit t h s, Edand it ionbr , is idg a ecom pr ot procol ehensive dat a un refer it s ence ( BPDUs) t hat. SDUs enables ar e inf orm netatwion or kin ungit sp rfrofessionals om u pper - tlayer o un derst pr ot ocols and an t hdatim def plem in e en a ser t cont vice em r eq por uest ar y tint o aerlow neterw ork laying er t echnologies. pr ot ocol. PDU Mast is OSI er t erm he t inolog er m s, ycon forcep a pack t s, t echn et . BPDUs ologies, are anused d devices by t he used span inningt oday t ree ' s net algor w ork it hm ing indu as h ello st ry .mLear essag n how es. t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ISO Hierarchy of Networks Lar ge net w ork s t y pically ar e org anized as hier ar chies. A hier archical or gan izat ion p rov ides such adv ant ag es as ease of m anag em ent , flexib ilit y , and a redu ct ion in un necessar y t r af fic. Thu s, t he I nt er nat ional Or ganizat ion for St andar dizat ion ( I SO) has adop t ed a num b er of t er m inology •conv en t ions fTable of ressin Contentgs n et wor k ent it ies. Key t erm s d ef ined in t his sect ion in clud e end sy st em or add •( ES) , int erm ediat I ndex e sy st em ( I S) , area, an d aut onom ous sy st em ( AS) . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

An ES isSystems, a net w or k dev ice t h at d oes not p er f orm r out ing or ot h er t raf fic f or w ard in g fun ct ion s. By Cisco Inc. Ty pical ESs in clud e such d ev ices as t erm inals, per sonal com put er s, and pr int er s. An I S is a net w or k dev ice t h at p er f orm s r out in g or ot her t r aff ic- for w ard ing fu nct ions. Ty pical I Ss inclu de Pub lish er: Cisco Press such devices as r out er s, sw it ches, and br idges. Tw o t yp es of I S net w ork s ex ist : int r adom ain I S e: Sep tem ber 1 1, 2 003 andPub intDat er dom ain I S. An in t rad om ain I S com m unicat es w it hin a single au t onom ous sy st em , w h ile I SBN: 58 705 19 -2m unicat es w it hin and bet w een aut onom ous sy st em s. An ar ea is a logical an int er dom1-ain I S-1com gr oup Pages: of net11 w28 or k seg m en t s and t heir at t ach ed dev ices. Ar eas are sub div isions of aut onom ous syst em s ( AS's) . An AS is a collect ion of net w ork s u nder a com m on adm inist r at ion t h at shar e a com mon r out ing st r at egy . Aut on omou s syst em s ar e subd iv ided int o ar eas, and an AS is som et im es called a d omain. Figur e 1- 1 2 illust r at es a h ier ar ch ical net w ork and it s comp onent s. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r e 1 - 1 2 . A H ie r ar ch ical Ne t w or k Cont ai ns N um e r ou s Com p on e nt s Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Connection-Oriented and Connectionless Network Services I n general, t ran sp ort pr ot ocols can be char act er ized as bein g eit h er con nect ion - orient ed or •connect ionless. Table of Content s or ien t ed serv ices m u st fir st est ablish a connect ion w it h t he desir ed Connect ion•ser v ice befor Iendex passing any dat a. A conn ect ionless ser v ice can sen d t he dat a w it hout any n eed t o Iest nt eablish rn et w orak ing chnologie , Four Edit ion ion - or ient ed ser v ices p rov ide som e level of conTe nect ion f irsstH.aIndbook n gener al, th con nect deliver y gu aran t ee, w h er eas connect ionless ser vices do not . By Cisco Systems, Inc. Con nect ion - orient ed ser v ice in volv es t hr ee phases: connect ion est ablishm ent , d at a t r ansf er , an d Pub lish er: Cisco Press connect ion t er m inat ion. Pub Dat e: Sep tem ber 1 1, 2 003

Du ringI SBN: conn1-ect 58 705 ion-1est 19 -2 ab lishm ent , t he end nod es m ay r eser v e r esour ces for t he connect ion. Th e end nodes also m ay n eg ot iat e and est ablish cer t ain crit er ia f or t he t ran sf er, su ch as a w indow Pages: 11 28 size used in TCP con nect ion s. This r esou rce r eser vat ion is on e of t he t h ings ex ploit ed in som e denial of ser vice ( DOS) at t ack s. An at t ack ing syst em w ill send man y r eq uest s for est ablishing a connect ion but t hen w ill never com plet e t he conn ect ion. The at t ack ed com put er is t hen left w it h r esour ces allocat ed for man y nev er - com plet ed connect ions. Then, w hen an end nod e t r ies t o com plet e an act u al connect ion, t h er e ar e n ot enoug h resour ces f or t h e valid connect ion. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial d sf cuert t ingedgoccur e t ech The d at a an t ran phase s nologies. w hen t he act ual dat a is t r ansmit t ed ov er t he conn ect ion. D ur ing dat a t r ansfer , m ost conn ect ion- or ient ed ser vices w ill mon it or for lost pack et s and hand le r esendin t hem. is olog g en er ally alsot ial r esp le kfor ing t h e als packatetall s inlev t hels, e r igf rom ht Congcise ov erThe v iewprsot ofocol t echn ies essen t o onsib n et wor ingp ut prtofession seq uence befor e p assing t he dat a up t he p rot ocol st ack . nov ice t o ex pert . WhenNew t he chapt t ran sfer ersof dat a iscov com p let h epor en tdant nodes t er like min at eP t he conEAP nect ion and r elease include erag e e, of tim t opics VoI and r esour ces r eserv ed for t h e connect ion. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Con nect ion - orient ed net w or k ser v ices hav e m or e ov er head t han connect ionless ones. Con nect - orient ser vSy ices m ustw negot a con nect ionw, or t r ansfer a, Iand Aution h ored by ed Cisco st ems, or ldw iat idee leader in net king f ord at t he n t er tnear et . dow n t h e connect ion, w h er eas a conn ect ionless t r ansfer can sim ply send t he d at a w it h out t he add ed ov head ofkcreat ing nologies and t ear ing dow n a, conn ion. Each it spr place in intrefer ern etence wor kts. I n ter ern et w or in g Tech Hand book Four tect h Ed it ion , is haas com ehensive hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Internetwork Addressing I n t ern et w or k ad dr esses id en t ify d ev ices separ at ely or as m emb er s of a gr oup. Addr essing sch em es v ar y dependin g on t h e pr ot ocol fam ily and t h e OSI lay er . Th r ee t yp es of in t er net w or k add resses ar e com m only used: dat a link lay er add resses, Media Access Cont rol ( MAC) •add resses, an Table ofwContent d n et or k lays er addr esses. •

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Data Link Layer Addresses By Cisco Systems, Inc.

Cisco AdatPub a lish linker:lay er Press addr ess u niqu ely ident if ies each phy sical net w ork con nect ion of a net w ork Pub Dat e: Sep tem 1 1,esses 2 003 som et im es ar e r ef err ed t o as ph ysical or har dw ar e ad dr esses. D at adev ice. Dat a- lin k ber addr I SBN: 158 705 -1 19 -2 link add r esses usually ex ist w it hin a flat ad dr ess sp ace an d hav e a pr e- est ablish ed and t y pically fix ed rPages: elat ionship t o a specif ic device. 11 28

En d sy st em s g en er ally hav e only on e ph ysical net w or k con nect ion an d t hus h ave only one d at alink add r ess. Rou t er s an d ot her int er net w ork ing dev ices t y pically hav e m ult iple ph ysical net w or k connect ions an d t h er efor e h ave m u lt ip le dat a- link ad dr esses. Figur e 1- 1 3 illust r at es how each int er face on a d ev ice is uniq uely id en t ified by a d at a- link add r ess. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu e 1ov - 1er3v .iew Ea I n t eolog r f ace on at ialDtev Unpriq ue ly als I den t i flev ie dels,byf rom a Con rcise s ch of t echn ies essen o n ice et worI ksing ofession at all Da t a - Lin k Addr e ss. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP [ View full size im age]

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

MAC Addresses Media Access Con t r ol ( MAC) ad dr esses consist of a sub set of dat a link lay er add resses. MAC add resses id en t ify net w or k ent it ies in LANs t hat im plem ent t he I EEE MAC addr esses of t he dat a link lay er . As wit h m ost d at a- link add resses, MAC add r esses are u niqu e for each LAN in t er f ace.

Figur e 1- 1 4 illust r at es t he relat ionship bet w een MAC addr esses, dat a- lin k addr esses, and t he I EEE sub lay er s of t he d at a link lay er.

Figu r e 1 - 1 4 . M AC Add r esse s, Da t a -Li nk Add r esse s, an d t he I EEE Subl ay er s of t he D at a Lin k La y er Ar e All Re la t e d •

Table of Content s

•

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. MAC add resses ar e 4 8 b it s in leng t h and are ex pr essed as 12 hex adecim al d ig it s. The f irst 6 hex adecim al dov igit w hich e adolog min ies ist eressen ed byt ial t het oI EEE, ident man uf actat u rer or vend and Con cise ers, v iew s of ar t echn n et wor k ingif yprt he ofession als all lev els, f or rom t hu s comp r ise t h e Or gan izat ion ally Uniq ue I dent if ier ( OUI ) . Th e last 6 hex adecim al d ig it s nov ice t o ex pert . com pr ise t h e int er face ser ial n um ber , or anot h er valu e adm inist er ed by t h e sp ecific v endor . MAC add resses som eterimes ar e called bu rn ed -im in por addt ant r esses ( BI As) ecau se t hey New chapt s include cov erag e of t opics like bVoI P and EAP are bur ned int o readonly m em ory ( ROM) and ar e copied int o r andom - access m em ory ( RAM) w hen t h e int er face card init ializes. Figur 1 5t ing illust r at es t he ologies MAC ad lik dr ess f or mat . wor k ing and st or age Cov erag e eof1-cut edge t echn e opt ical n et Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et wFigu or k inrgeTech book , Fouress t h EdCont it ion , aisin a scom ehensive refer t hat 1 - 1nologies 5 . Th eHand M AC Addr a pr Un iqu e For mence a t of enables net w or kin g p r ofessionals t oHe un derst and an d im plem en t cont em por ar y int er net w ork ing x ade ci m al Di gi t s t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Mapping Addresses Becau se in t ern et w or k s gener ally use net w ork addr esses t o rou t e t r aff ic ar ound t h e net w ork , t her e is a need t o map n et w or k add r esses t o MAC add resses. Wh en t h e net w or k layer has det er min ed t he dest in at ion st at ion' s n et w or k add r ess, it m ust for w ar d t he inf orm at ion ov er a • Table of Content s ph ysical net w or k using a MAC ad dr ess. Dif fer en t pr ot ocol suit es u se d iff er ent met h ods t o perf or m • I ndex t his m ap ping, but t he most popu lar is Addr ess Resolu t ion Pr ot ocol ( ARP) . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

By Systems, Inc.suit es u se d iff er ent met hod s for det erm ining t h e MAC addr ess of a dev ice. Th e DifCisco ferent pr ot ocol follow ing t hr ee m et hods ar e u sed m ost of t en . Add ress Resolu t ion Pr ot ocol ( ARP) m aps net w ork addPub resses MAC add resses. The Hello p rot ocol en ables net w ork devices t o lear n t h e MAC lish er:t o Cisco Press addPub resses of ot h er Dat e: Sep tem bernet 1 1,w2ork 003 devices. MAC ad dr esses eit her ar e em bedd ed in t he net w ork lay er add ress or ar e gener at ed by an algor it hm . I SBN: 1- 58 705 -1 19 -2

Pages: 11 28 t ion Prot ocol ( ARP) is t he m et hod used in t he TCP/ I P suit e. When a n et wor k Add ress Resolu dev ice n eeds t o send dat a t o an ot her dev ice on t h e sam e n et wor k , it kn ows t he sour ce and dest inat ion net w or k addr esses f or t he d at a t r an sf er . I t m ust som eh ow m ap t he d est inat ion add ress t o a MAC add ress befor e f or w ard in g t he dat a. Fir st , t h e sen ding st at ion w ill check it s ARP t able t o see if it has alr ead y discov er ed t his dest in at ion st at ion' s MAC add ress. I f it has not , it w ill sendeda edit b road w or k allw it inh t one he d net est inat ion s I Ppadd ess cont ained in t he The u pdat ioncast of ton he tbhe estnet - selling w ork ingstrat efion' erence rovrides cover age of br oadcast . Ever at ion t h e nologies. net w or k r eceiv es t he br oadcast and com par es t he em bedded I P essent ial an d cuyt t st ingedgon e t ech add ress t o it s ow n. On ly t he st at ion w it h t he m at ching I P ad dr ess r eplies t o t h e sen ding st at ion w it h a pack et cont ainin g t he MAC add ress for t he st at ion. The f ir st st at ion t h en add s t his ciset ooviter v iew st able of t echn olog essen t ialand t o npr etoceed wor k ing ofession inf ormCon at ion s ARP for fut ur ies e r ef er ence s t oprt ran sf er tals he datatall a. lev els, f rom nov ice t o ex pert . When t he dest in at ion d ev ice lies on a rem ot e net w or k, one b ey ond a rou t er , t he pr ocess is t he chapt er st he include covst erag e of im por t ant t opics like VoI and EAP sam eNew ex cep t t h at sen ding at ion send s t he ARP r equest f or P t he MAC ad dr ess of it s default gat ew ay . I t t h en f orw ar ds t he inf or mat ion t o t hat dev ice. The default gat ew ay w ill t hen for w ar d erag e of cut twing echn ologies lik e opt n et er wort he k ing and stt oortage t he inCov for m at ion over hatedge ev er tnet w or ks n ecessar y tical o deliv packet h e net w or k on wh ich t he dest in at ion d ev ice r esides. The r out er on t h e dest in at ion device' s net w or k t h en uses ARP t o Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . obt ain t h e MAC of t he act ual dest in at ion d ev ice and deliver s t he packet .

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat The Hello p rot ocol is a net w or k layer p rot ocol t hat en ables net w ork devices t o ident if y one enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing anot h er and indicat e t h at t h ey ar e st ill f unct ional. W hen a new end syst em p ower s up , for t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing exam ple, it br oadcast s hello m essages ont o t h e net w ork . D ev ices on t h e net w or k t hen ret u rn indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . hello r eplies, an d h ello messag es are also sent at sp ecific in t er v als t o in dicat e t hat t hey ar e st ill Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, fu nct ional. Net w or k devices can lear n t he MAC add resses of ot h er devices by ex amin in g Hello and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all pr ot ocol p ack et s. net w or kin g p rof essionals, r egar dless of ex pert ise. Thr ee pr ot ocols use pr edict able MAC add resses. I n t hese pr ot ocol suit es, MAC addr esses ar e Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e pr edict able because t he net w ork lay er eit her emb ed s t he MAC ad dr ess in t he net w ork lay er har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on add ress or u ses an algor it hm t o det er min e t he MAC ad dr ess. The t hr ee pr ot ocols are Xer ox a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Net w ork Sy st ems ( XNS) , Nov ell I nt er net w or k Packet Ex ch ange ( I PX) , and DECnet Ph ase I V. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Network Addresses pr of essionalsLayer oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions t h eir w ork s. t ifies an en t it y at t he net w or k layer of t h e OSI lay ers. Net w or k Anet w or k for lay er addnet ress id en add resses u su ally ex ist w it hin a h ier ar ch ical addr ess sp ace and som et im es are called v ir t ual or logical addr esses. The r elat ionship bet w een a n et w or k ad dr ess an d a dev ice is logical an d u nf ix ed; it t y pically is based eit her on p hy sical net w or k char act er ist ics ( t he d ev ice is on a par t icular net w or k seg m en t )

or on gr oup ings t hat h ave no p hy sical b asis ( t he dev ice is par t of an App leTalk zone) . End syst em s r eq uir e one n et w or k lay er addr ess for each net w ork lay er pr ot ocol t h at t h ey sup por t . ( This assum es t hat t he device has on ly one p hy sical net w or k connect ion. ) Rout er s and ot her int er net w ork ing dev ices r equir e one net w ork lay er add ress per ph ysical net w or k connect ion for each n et w or k lay er pr ot ocol suppor t ed. For ex am ple, a r out er w it h t h ree int er faces each r un ning App leTalk , TCP/ I P, an d OSI m ust h ave t hr ee net w ork lay er add resses f or each int er face. The r out er t h er efor e has nine n et w or k lay er addr esses. Figur e 1- 1 6 illust r at es how each net w or k int er face m ust be assig ned a net w or k addr ess for each pr ot ocol supp ort ed . • Table of Content s •

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Figu r e 1 - 1 6 . Ea ch Ne t w or k I nt er f ace M ust Be Assign ed a Ne t w or k Ad dr ess f or Ea ch Pr ot ocol Su ppor t e d

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Hierarchical Versus Flat Address Space pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Idecisions nt er net w for ork taddr ace h eir ess net wspork s. t yp ically t ak es one of t w o for m s: hier archical ad dr ess space or f lat add ress space. A hierar chical ad dr ess space is org anized int o nu mer ous sub gr oup s, each successiv ely nar r ow in g an ad dr ess u nt il it point s t o a sing le device ( in a m ann er sim ilar t o st r eet add resses) . A flat addr ess sp ace is org anized int o a sing le gr oup ( in a m ann er sim ilar t o U. S. Social Secu rit y n um ber s) . Hier ar chical add ressin g of fer s cer t ain adv ant ag es over f lat - addr essing schemes. Add ress sort in g

and r ecall is sim plified using com par ison operat ion s. For ex am ple, " I reland " in a st r eet addr ess elim inat es an y ot her coun t ry as a p ossible locat ion. Figur e 1- 1 7 illust r at es t he diff er ence bet w een hier ar ch ical an d flat ad dr ess sp aces.

Figu r e 1 - 1 7 . H ie r ar ch ical a nd Fl at Addr e ss Spa ces D if f er in Com par i son O pe r at i ons • Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

[ View full size im age]

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Address Assignments indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e wariteh assigned new an d u chapt er s of ont w secur it yes: , ststoratage, optdy ical netic. w or scalabilit Add resses t opdat d eved ices as one o t yp ic and nam Stkatinicg,add ressesy,ar e and speed, t h is book is a com plet e an d u pt od at e r ef er ence t o t he t op ics t hat are essen t ialp lan t o all assig ned b y a n et w or k ad min ist r at or accor ding t o a pr econ ceiv ed int er net w or k addr essing . net w or kin g p rof essionals, r egar dless of ex pert ise. A st at ic ad dr ess d oes not ch ange u nt il t h e net w or k adm inist r at or m anually chan ges it . Dy nam ic add resses ar e ob t ained b y dev ices w hen t hey at t ach t o a net w or k, by m eans of som e pr ot ocolReader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e specif ic pr ocess. A d ev ice using a d yn amic ad dr ess of t en has a diff er ent addr ess each t im e t hat it har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on connect s t o t he n et w or k . Som e net w or ks use a serv er t o assign add resses. Ser ver - assign ed a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions add resses ar e r ecy cled f or r eu se as devices discon nect . A d ev ice is t her ef or e lik ely t o h ave a t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . dif fer en t add r ess each t im e t h at it con nect s t o t he net w or k. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Addresses Versus pr odu ct iv it y an d im pr ov e Names eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. I nt er net w ork devices usually hav e bot h a nam e and an add ress associat ed wit h t h em . I nt er net w ork nam es t yp ically ar e locat ion- independ en t an d r em ain associat ed w it h a dev ice w her ev er t hat dev ice m ov es ( for ex am ple, fr om on e buildin g t o anot h er ) . I n t er n et w or k add resses u su ally are locat ion- d ep en dent and change w hen a device is m ov ed ( alt h ough MAC add resses ar e an except ion t o t his r ule) . As w it h net w or k addr esses being m app ed t o MAC

add resses, n ames ar e usually m app ed t o net w or k addr esses t h rou gh some p r ot ocol. The I nt er net u ses Dom ain Nam e Syst em ( DNS) t o map t h e nam e of a d ev ice t o it s I P addr ess. For exam ple, it ' s easier f or y ou t o r em em ber w w w .cisco. com inst ead of som e I P ad dr ess. Th er efor e, y ou t yp e w w w. cisco. com int o you r br ow ser wh en y ou w ant t o access Cisco's w eb sit e. You r com put er p er for m s a DNS look up of t he I P addr ess for Cisco' s w eb ser v er and t hen com mu nicat es wit h it usin g t he n et w or k add r ess. •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Flow Control Basics Flow cont r ol is a fun ct ion t h at p rev en t s net w or k congest ion b y ensur ing t hat t r ansmit t in g devices do not over w helm r eceiving dev ices w it h dat a. A hig h- speed com put er , f or exam ple, m ay gener at e t r aff ic fast er t h an t he net w or k can t ran sf er it , or f ast er t han t he d est inat ion dev ice can •r eceive and pr Table of Content ocess it . Th es t hr ee comm only u sed m et hods f or han dling net w or k congest ion ar e •bu ff er ing , t r ansm I ndex it t in g sou rce- quench m essages, and w indow ing . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Buf fer ing is usedInc. b y net w ork devices t o t em por ar ily st or e b ur st s of ex cess d at a in m em or y u nt il By Cisco Systems, t hey can be p rocessed. Occasional d at a b ur st s are easily han dled by buf fer ing. Excess dat a bu rst s can exh aust m em ory , h owev er, for cin g t he dev ice t o discard an y addit ional dat ag ram s Pub lish er: Cisco Press t hat ar r iv e. Pub Dat e: Sep tem ber 1 1, 2 003 1- 58 705 -1 19 -2 Sour ce-I SBN: quench messages ar e used b y receiv ing dev ices t o help p rev ent t heir buf fer s fr om ov er f low Pages: ing 11 . The 28 receiv ing dev ice sends sou rce- quench m essages t o requ est t hat t he sour ce r ed uce it s cur r en t r at e of d at a t r ansm ission. Fir st , t he receiv ing dev ice b eg ins discard ing r eceived dat a due t o ov erf lowin g b uf fers. Second, t he r eceiv ing device begin s send ing sou r cequ en ch m essages t o t he t ran sm it t ing d ev ice at t h e r at e of one m essag e for each packet dr opped. The sou rce dev ice receiv es t he sour ce- quench m essages and low er s t he dat a r at e un t il it st op s rThe eceivin g ted h e edit m essages. Finbally t h e sour ceindevice t hen gring adurally in cr eases he dat a r at e as u pdat ion of t he est ,- selling allone net w ork ef erence p rov tides cover age of long as n o fu r t her sour ceq uench r equest s ar e r eceived. essent ial an d cu t t ing- edg e t ech nologies.

Wind owin g is a flow - cont r ol schem e in wh ich t h e sou rce d ev ice r eq uires an ack now led gm en t fr om Con t he cise dest inat afts er cer t ain b er oft ial p ack s hav b een t r ansm itals t ed at . Wit aw indf ow ov erion v iew of at echn olognum ies essen t o et n et worek ing pr ofession allhlev els, rom size of 3, t h e sour ce requ ires an ackn ow ledg m en t af t er send ing t hr ee packet s, as f ollows. Fir st , nov ice t o ex pert . t he sou rce d ev ice send s t hr ee pack et s t o t h e dest inat ion device. Then, af t er r eceiving t h e t hr ee pack et s, t he dest ion devcov iceerag sends gm ent t o VoI t h ePsou The sou rce r eceiv es t he New chapt erinat s include e ofanimack pornow t antled t opics like andrce. EAP ackn ow ledg m en t and sends t hr ee mor e p ack et s. I f t he dest inat ion does not r eceive one or m or e of t heCov packet eragsef of or cut som t ing e reason, edge t echn suchologies as ov erf liklow e opt in gical b ufnfer et s, wor it kdoes ing and not st r eceive or age en ough pack et s t o send an ackn ow ledg ment . The sour ce t hen r et ran sm it s t h e pack et s at a redu ced t r ansm ission r at e. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Error-Checking Basics Er r or - ch eck ing sch em es det erm ine wh et her t r ansm it t ed dat a has becom e cor ru pt or ot her w ise dam aged w hile t r av eling fr om t he sour ce t o t he dest inat ion. Er ror ch eck ing is imp lem ent ed at sev er al of t he OSI layer s. •

Table of Content s

•On e com m onI ndex err or - check ing sch em e is t he cyclic r ed und ancy check ( CRC) , w hich d et ect s an d Idiscard nt e rn et w k ing chnologie ndbook Four th fEdit ion s or corr upTet ed d at a. sErH raor - cor r,ect ion unct ions ( su ch as d at a r et r ansmission) ar e left t o high er lay er pr ot ocols. A CRC v alue is g en er at ed by a calculat ion t hat is per for m ed at t he sour ce By Cisco Systems, Inc. dev ice. Th e dest in at ion d ev ice comp ares t h is valu e t o it s own calculat ion t o det er min e w het her err or s occur red du ring t r ansm ission. Fir st , t h e sou r ce d ev ice per for m s a p redet er min ed set of Pub lish er: Cisco Press calcu lat ion s ov er t he cont ent s of t he pack et t o be sent . Th en , t he sou rce p laces t he calculat ed Pub Dat e: Sep tem ber 1 1, 2 003 v alue in t he p ack et an d sends t he p ack et t o t he d est inat ion . The d est inat ion p er for m s t h e same I SBN:ined 1- 58 705 19 -2 pr edet erm set-1of calculat ions over t h e cont ent s of t h e pack et and t hen comp ar es it s Pages: 11 28e w it h t hat cont ain ed in t he p acket . I f t he values ar e equ al, t he p ack et is com put ed valu considered v alid . I f t he v alues ar e unequ al, t he p ack et cont ain s err or s and is d iscar ded.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Multiplexing Basics Mu lt iplex in g is a pr ocess in w hich mu lt iple dat a ch annels ar e com bined in t o a sin gle dat a or ph ysical chann el at t h e sour ce. Mu lt iplex ing can be im plement ed at any of t he OSI lay er s. Con ver sely , dem ult ip lexing is t he pr ocess of separ at ing m ult iplexed dat a chann els at t he •dest inat ion. One Tableex of amp Content s m ult iplex ing is w hen dat a fr om m ult ip le applicat ions is m ult iplex ed le of •int o a single Ilow ndex er - layer dat a pack et . Figur e 1- 1 8 illust r at es t his ex am ple. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 1 - 1 8 . M u lt ipl e Appl icat ions Ca n B e M ul t ip le xe d i nt o a Sin gle Low er - La ye r D at a Pack e t Pub Dat e: Sep tem ber 1 1, 2 003

Pub lish er: Cisco Press

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Anot h er ex am ple of m ult iplex in g is wh en d at a f rom mu lt iple dev ices is com bined in t o a sin gle ph el Tech ( using a dev ice called ult iplexer . Figur 1- 1 pr 9 illust r at esrefer t his ence ex amtple. I n tysical ern et wchann or k in g nologies Hand booka, m Four t h Ed it )ion , is ae com ehensive hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Figu r ee w 1 it- 1h 9new . Man u lt ipl e ed Dechapt vi ces Be itM ipage, le xe dical i ntnet oa Sin glescalabilit Ph ysica Com plet du pdat er sCa onnsecur y ,ul sttor opt w or k in g, y, l and speed, t h is book is a com plet e an d u p- tCha o- d atnn e rel ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Am ult ip lexer is a ph ysical layer d ev ice t hat comb in es mu lt iple dat a st ream s int o one or mor e out p ut ch annels at t he sour ce. Mult iplex er s d em ult iplex t h e ch annels int o m ult iple dat a st r eam s at t he r emot e en d and t hus max im ize t he u se of t he ban dw idt h of t he phy sical medium by enabling it t o be sh ared by m u lt ip le t r affic sou rces.

Som e m et hods u sed for mu lt iplex ing dat a ar e t im e- d ivision m u lt ip lex ing ( TDM) , asy nchr on ous t im e- division mu lt ip lex ing ( ATDM) , fr equency - div ision m ult iplexing ( FDM) , and st at ist ical m ult iplexin g. I n TDM, inf or mat ion f rom each dat a chann el is allocat ed band wid t h based on pr eassign ed t im e slot s, regar d less of w het her t h er e is d at a t o t r ansmit . I n ATDM, inf orm at ion fr om d at a chan nels is allocat ed ban dw idt h as needed by using dy nam ically assign ed t im e slot s. I n FDM, in for m at ion fr om each dat a ch annel is allocat ed b andw idt h b ased on t he signal fr equency of t h e t r aff ic. I n • Table of Content s st at ist ical mu lt ip lex ing, band w id t h is dy nam ically allocat ed t o any d at a chan nels t hat hav e • I ndex inf orm at ion t o t ran sm it . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Standards Organizations A w ide var iet y of or ganizat ions con t r ib ut e t o int er net w ork ing st andar d s by p rov iding f oru ms for discussion , t ur ning inf or mal discu ssion int o for m al specif icat ion s, and pr olif erat in g specificat ions aft er t hey ar e st andar dized. •

Table of Content s

•Most st an darIds ndex or gan izat ions cr eat e f or m al st andar ds by using specif ic pr ocesses: or ganizing Iideas, nt e rn etdiscu w or k ing Te chnologie s oach, H a ndbook th Edit ssing t h e appr d ev, Four eloping drion af t st and ard s, vot in g on all or cer t ain asp ect s of tBy heCisco st anSystems, dar ds, and t h en f orm ally r eleasing t he com plet ed st and ar d t o t he public. Inc.

Som e of t he b est - k now n st and ard s or ganizat ions t hat con t r ib ut e t o int er net w ork ing st and ard s Pub lish er: Cisco Press include t hese: Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

IPages: nt e rn11at28i ona l Org an iz at i on for St a nda r diz a t ion ( I SO) — I SO is an int er nat ional st andar d s or ganizat ion r espon sible f or a w id e r ange of st an dar ds, including m any t hat are r elev ant t o net w or k in g. I t s b est - k now n cont r ibut ion is t h e dev elopm ent of t he OSI r ef erence m odel an d t he OSI pr ot ocol su it e. Am e ri ca n N at iona l St a nda rd s I nst it ut e ( AN SI ) — ANSI , w h ich is also a mem ber of t h e The uIpdat ion ofinat t heing b est - selling in-t ary one stnet orkds ing r ef ps erence p rov of SO, ed is tedit h e coord bod y for vallolun anw dar g rou w it hin t h eides Un itcover ed Stage at es. essentANSI ial andev d cu t t ingedg e t ech nologies. elop ed t h e Fib er D ist r ibu t ed Dat a I nt er face ( FDDI ) and ot her com mu nicat ions st andar d s. Con cise ovcerI nd v iew s of t echn olog ies essen ial— t oEI n et k ing ofession at all lev els, f rom Ele ct roni ust ri es A ssocia t ion ( EI tA) A wor specif ies pr elect rical tals r ansm ission nov ice t o ex pert . st andar d s, in clu ding t hose u sed in n et w or k ing. The EI A developed t he w idely used EI A/ TI A23 2 st an dar d ( for m er ly k now n as RS- 2 32) . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP I nst i t ut e of Ele ct ri ca l a nd Ele ct roni c Engi ne er s ( I EEE) — I EEE is a p rof essional Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age or ganizat ion t hat def in es net w ork ing and ot h er st an dar ds. The I EEE developed t he w idely used LAN by st and ard Sy s I st EEE 8 02. 3 and I EEE 80 2.in 5. net w or king f or t he I n t er n et . Aut h ored Cisco ems, w or ldw ide leader ntweor rnkat l Tel ecom m unibook ca t i on U niton Te un ica ion St a nda rdence iz a t ion I n t ernI et inigona Tech nologies Hand , Four h Ed it le ioncom , is m a com pr tehensive refer t hat Se ct or ( I TUT) — For m erly called t h e Com m it t ee for I nt er nat ion al Telegr aph an dw ork ing enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net Telep hone ( CCI TUT is now t er n ologies, at ional or izat ion tused h at din evtelop t echnologies. Mast er TT) t he, tIer m s, con cepan t s, in t echn angan d devices odays ' s net w ork ing com mu nicat ion st and ar ds. The I TUT d ev elop ed X. 25 and ot h er com m un icat env ionsirst an dar indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN onm entds. . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, I nt e rn et Act iv i t ie s Boar d ( I AB) — I AB is a g rou p of in t er net w or k r esear ch er s w h o discuss and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all issu es p er t in en t t o t he I nt er net and set I n t ern et policies t h r ough decisions and t ask for ces. net w or kin g p rof essionals, r egar dless of ex pert ise. The I AB desig nat es some Req uest For Com m ent s ( RFC) docum ent s as I nt ern et st and ard s, includin g Train ansm rolstProt ocol/ofI nt er net ot ocoln et ( TCP/ e Simp Reader s w ill obt a gission reat er Cont un der an ding LAN andPrWAN w or kI P) ing,and p art h t icu lar ly le t h Net e w or k Man agement Pr ot ocol ( SNMP) . har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary This chap t er int r oduced t he b uilding blocks on w h ich int er net w ork s ar e b uilt . Under st an ding w her e comp lex p ieces of int ern et wor k s f it int o t he OSI m odel w ill help y ou un derst and t h e concep t s bet t er . I nt er net w ork s ar e com plex sy st ems t hat , wh en v iew ed as a w h ole, ar e t oo m uch •t o und er st and. Table of Content s Only b y br eaking t h e net w or k dow n int o t he concept ual pieces can it be easily •un derst ood . As I ndex y ou r ead and exp er ien ce int ern et wor k s, t r y t o t hink of t h em in t er m s of OSI Ilay nt eer rnsetand w or kconcept ing Te chnologie s H a ndbook , Four th Edit ion ual pieces. By Cisco Systems, Inc.

Under st anding t h e int eract ion bet w een v ar iou s layer s and pr ot ocols m ak es d esign ing, conf ig ur ing, and diagnosing int er net w or ks p ossible. Wit h out under st andin g of t h e bu ild in g Pub lish er: Cisco Press block s, you cannot un derst an d t h e int er act ion bet w een t h em . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What ar e t he lay er s of t he OSI m odel?

2:

I ndex layer d et er m in es pat h select ion in an int ern et wor k ? Which

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : What By Cisco Systems, Inc.t y pes 4:

of t hin gs ar e def in ed at t he p hy sical lay er ?

What is one met hod of m app ing net w ork addr esses t o MAC ad dr esses?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

Which includes m or e over head, con nect ion - orient ed or connect ionless ser vices?

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Cisco' s w eb sit e (w w w .cisco. com ) is a w ond er f ul sour ce for mor e inf or mat ion ab out t hese t opics. The D ocu m en t at ion sect ion includ es in - dept h discussion s on man y of t he t opics cov ered •in t his chapt er Table . of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

• Tear e, Diane. Designing Cisco Net w or ks. I nd ianapolis: Cisco Pr ess, Ju ly 199 9. By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 2. Introduction to LAN Protocols Obj e ct i ve s • •

Table of Content s

Lear n about diff erent LAN pr ot ocols. I ndex

I nt e rn Under et w or k st ingand Te chnologie s Hen a ndbook , Four Edit ion t he d if fer t m et hod s th used t o deal

w it h m ed ia cont ent ion.

By Cisco Systems, Inc.

Lear n about diff erent LAN t opologies. Pub lish er: Cisco Press

This chap t er int r oduces t he var ious m edia- access m et hods, t ran sm ission m et hods, t op ologies, Dat e: Sep tem ber 1 1, 2 003 andPub dev ices u sed in a local- ar ea n et w or k ( LAN) . Topics add ressed focus on t he m et hods and I 1- 58 19 -2et / I EEE 80 2. 3, Tok en Ring/ I EEE 8 02. 5 , and Fib er Dist rib ut ed D at a dev icesSBN: used in 705 Et -1 hern Pages: 11 28 ) . Su bseq uent ch apt er s in Par t I I , " LAN Pr ot ocols, " addr ess sp ecific p rot ocols in I nt er face ( FDDI m or e det ail. Figur e 2- 1 illust r at es t he basic lay out of t hese t hr ee im plement at ion s.

e edit 2 - 1ion . Thr e eb est LAN I m ple me nt anet t iwons Arreef erence Use d pMrov ost onofly The Figu u pdat red of t he - selling all- inone ork ing idesCom coverm age essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

What Is a LAN? ALAN is a high - speed dat a net w or k t hat cover s a r elat ively sm all geogr aphic area. I t t yp ically connect s w or kst at ion s, personal com pu t ers, p rin t er s, serv ers, an d ot her dev ices. LANs of fer com put er u ser s m any adv ant ages, in clu ding shar ed access t o dev ices and app licat ions, f ile •exchan ge b etTable Content w eenofconn ectsed user s, an d com m unicat ion bet w een user s v ia elect r on ic mail and •ot her ap plicat I ndex ion s. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

LAN Protocols and the OSI Reference Model LAN pr ot ocols fun ct ion at t he low est t w o layer s of t he OSI r ef er ence m odel, as d iscussed in Ch apt er 1, " I nt er net w or kin g Basics, " bet w een t he p hy sical lay er and t he dat a link lay er . Figur e 2- 2 illust r at es how sev er al p opular LAN p rot ocols m ap t o t h e OSI r efer en ce mod el. •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Figu r e 2 - 2 . Pop ul ar LAN Pr ot ocol s M ap ped t o t he O SI Re f er e nce M od el

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

LAN Media-Access Methods Media con t en t ion occur s w hen t w o or mor e n et w or k d ev ices h ave d at a t o sen d at t h e sam e t im e. Becau se mu lt ip le devices cannot t alk on t he n et wor k sim ult aneously , some t yp e of m et h od m u st be u sed t o allow one dev ice access t o t h e net w or k media at a t im e. This is don e in t wo m ain •w ay s: carr ierTable of Content sen se m u lt ip sle access collision d et ect ( CSMA/ CD ) and t ok en p assing . •

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I nt rn et or ksing Te chnologie H a ndbook , Fourythsuch Edit ion n enet wwork u sing CSMA/sCD t echn olog as Et her net , n et w or k d ev ices cont en d f or t he net w or k m ed ia. When a d ev ice has dat a t o send , it f ir st list ens t o see if any ot her d ev ice is By Cisco Systems, Inc. cur r en t ly using t he n et w or k . I f not , it st art s sen ding it s dat a. Aft er f in ish ing it s t r ansm ission, it list en s again t o see if a collision occur r ed. A collision occur s w hen t w o d ev ices send dat a Pub lish er: Cisco Press simu lt aneously. W hen a collision h appens, each device w ait s a ran dom lengt h of t im e b ef ore Pub Dat e: Sep tem ber 1 1, 2 003 r esendin g it s dat a. I n m ost cases, a collision w ill not occu r again bet w een t h e t w o d ev ices. I SBN: 58 705 -1 19of -2 n et w or k cont ent ion , t he b usier a net w or k becom es, t h e m ore collision s Becau se of 1t his t y pe 11 28 occu r .Pages: This is w hy perf or man ce of Et her net d eg rad es rap idly as t he num ber of d ev ices on a single n et w or k incr eases.

I n t ok en - passing n et wor k s such as Tok en Ring an d FDD I , a special net w ork packet called a t ok en is passed ar oun d t he net w or k fr om device t o device. When a dev ice has dat a t o send , it m ust w ait uupdat nt il it e tof ok en en sends s one dat a.net Wh h e dat a t r ansmission com age plet e, The edhas editt h ion t heand b estt -hselling all-itinw en orkting r ef erence p rov idesiscover of t he tessent ok en is r eleased so t hat ot her dev ices m ay use t h e net w or k m ed ia. The m ain adv ant age of ial an d cu t t ing- edg e t ech nologies. t ok en - passin g net w ork s is t h at t h ey are det er m inist ic. I n ot h er w or ds, it is easy t o calcu lat e t he m axim um t ime t hat w ill pass befor e a device has t he op por t unit y t o sen d dat a. Th is ex plains t he pop ular it ycise of tov okenpassing n et wolog or k sies in essen som et rial ealenvkiring onm s suchals asatfact ies, er e Con er v iew s of t echn t ot ime n et wor prent ofession allorlev els,whf rom m achinery cap nov icemu t o stexbe pert . able of comm un icat in g at a det er m inable in t er v al. For CSMA/ CD n et k s, swit ches segm t het ant net twopics or k int o m ultPiple dom ains. This New chapt erwor s include cov erag e of ent im por like VoI andcollision EAP r ed uces t he n um ber of dev ices per n et w or k segm en t t h at m ust cont end for t he m edia. By creat ing Covsm erag aller e ofcollision cut t ing dom edgeains, t echnt hologies e per forlik meance opt ical of an et n et wor w or k ing k can and bestincr or age eased sig nificant ly w it hout r equir ing addr essing chan ges. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Nor mally CSMA/ CD net w or ks ar e h alf- du plex, meaning t h at w h ile a dev ice sends in for m at ion, it I n t ern etrw or k in gatTech Hand book , Fouris t ht alk Ed iting, ion ,itisisaincapab com pr ehensive ence ftor hatot her cannot eceive t h e nologies t ime. W hile t hat device le of also refer list ening net wisormkin g plik r ofessionals o un derst andone an dperson im plem en t scont int er net ing it tenables r aff ic. This uch e a w alk ie- t alkie. Wh en w ant t o tem alk por , hearpyresses t hewtork r ansm t echnologies. Mast er t he ing. t er mWhile s, conhe cepist s,t alk t echn d devices used fr inequency t oday ' s net bu t t on and begins sp eak ing ,ologies, no one an else on t h e same canwtork alk.ing indu st ry . Lear t o incor at e inthe er net w or kintghet echn ologities t o aand LAN/ env ir onm When t he sendninhow g person is por finished, r eleases t r ansm b utint on t h eWAN fr equency is ent . Com pletlee tw av ailab o itothhnew er s. an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w orsw When kinitgchpes rofar essionals, e int rod uced r egar , fu dless ll- dup of lex ex pert op erise. at ion is possib le. Full- d uplex w or ks m u ch like a t elep hone—y ou can list en as w ell as t alk at t he sam e t im e. When a n et w or k d ev ice is at t ached Reader aint of a gareat an ding and WAN n etcapab w or k ing, ar t icu lar e lldir ect lyst w o ill t heobt por neter w orun k der sw itstch, t he tof w oLAN devices m ay be le ofp operat in gly int hfu har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov du plex mod e. I n f ull- dup lex m od e, perf or man ce can be in cr eased , bu t not qu it e as m uchided as on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest som e lik e t o claim . A 100 - Mbp s Et h er net segm ent is cap able of t r ansm it t ing 200 Mb ps of d ations a, tbu o tenon sulyre100 conMb cept eh en and et en t ion, ionalser esou funect rt herion stsudy pscomp can trrav el sion in one d irrect ion at aand t imad e. dit Becau mostr ces dat af orcon ar e. Cov erag end only t o new n etdir wor ing tconcep t s,otbut old eris, not legacy asym m eter is ic also ( w it hext m or e ed datnaott r av eling in one ectk ion h an t he her also ) , t h et ogain as gr eat syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent as m any claim . How ev er , fu ll- d uplex oper at ion does increase t he t hr ough put of m ost s in w hich pr oflicat essionals oper at Tools and f orlonger opt im izing systTw em for m ance ill dup incrlex ease app ions becau see.t he net w or kgu mid edelines ia is no shar ed. o per devices on a fwullpr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient connect ion can sen d dat a as soon as it is r ead y. decisions for t h eir net w ork s. Tok en - passin g n et wor k s such as Tok en Ring can also benefit fr om n et w or k sw it ch es. I n lar ge net w or ks, t he delay bet w een t u rn s t o t ran sm it may be signif ican t because t he t oken is passed ar ound t h e net w or k.

LAN Transmission Methods LAN dat a t r ansmission s fall in t o t hr ee classif icat ion s: un icast , m ult icast , and br oadcast . I n each t y pe of t r ansm ission, a single p ack et is sent t o on e or m or e nodes. •I n a un icast tTable of ission Content r ansm , sa sin gle pack et is sen t f r om t he sour ce t o a d est inat ion on a n et w or k . •First , t he sour I ndex ce node ad dr esses t he p acket b y using t he addr ess of t he dest inat ion nod e. Th e Ipack nt e rnage et w or chnologie a ndbook Four Editfinally ion isk ting h enTesent on t os Ht he net w,or k, th and , t h e net w ork passes t h e pack et t o it s dest inat ion. By Cisco Systems, Inc.

Am ult icast t r an sm ission con sist s of a sing le dat a packet t hat is cop ied and sent t o a sp ecific Pub lish er: Cisco Press subset of n odes on t he n et w or k . Fir st , t h e sour ce node ad dr esses t he p ack et b y using a m u lt icast DatThe e: Sepptem 1, t2h003 addPub ress. ackber et 1is en sent in t o t h e net w or k, w hich m ak es cop ies of t h e pack et and sen ds a I SBN: 158 705 -1 19 -2 is par t of t he m ult icast add ress. copy t o each nod e t hat Pages: 11 28

Abr oadcast t ran sm ission con sist s of a sing le dat a packet t hat is cop ied and sent t o all n odes on t he net w ork . I n t hese t y pes of t r ansm issions, t he sou rce n ode add resses t he pack et by usin g t he br oadcast ad dr ess. Th e packet is t hen sent on t o t he net w or k, w hich m ak es cop ies of t h e pack et and sends a copy t o ev ery node on t h e net w or k. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

LAN Topologies LAN t opologies def in e t he m an ner in w h ich net w or k dev ices ar e or ganized. Fou r com m on LAN t opolog ies ex ist : bu s, ring , st ar , and t r ee. These t opologies ar e logical ar ch it ect ur es, but t he act ual d ev ices need not be p hy sically or ganized in t h ese conf igur at ions. Logical bu s and r in g •t opolog ies, f or Table of Content exam ple, arse com mon ly org anized p hy sically as a st ar . A bu s t opology is a linear •LAN arch it ectI ur ndex e in w hich t ran sm ission s fr om n et w or k st at ions pr opagat e t he lengt h of t h e Im nted e rn et w or ingarTe a ndbook , Four ionOf t he t hr ee m ost w idely used LAN ium ank d e chnologie r eceiv eds Hby all ot her stthatEdit ions. im Cisco plem Systems, ent at ion Inc. s, Et her net / I EEE 8 02. 3 net w or ks—includin g 1 00BaseT—im plem ent a b us By t opolog y, wh ich is illust r at ed in Figur e 2- 3 . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Figu r e 2 - 3 . Som e Ne t w or k s I m p le m en t a Local Bu s Topology

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Ar in g t op ology is a LAN arch it ect ur e t h at consist s of a ser ies of d ev ices conn ect ed t o on e anot h er Conect cise ovalert vr ansm iew s of t echn essen ial t o nclosed et wor kloop. ing prBot ofession alsRing/ at allI EEE lev els, f rom by u nidir ion ission linolog ks t ies o for m a tsingle h Tok en 8 02. 5 nov ice t o ex pert . and FDDI net w ork s im plement a ring t op ology . Figur e 2- 4 d ep ict s a logical r ing t opolog y. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Figu r e 2 - 4 . Som e Ne t w or k s I m p le m en t a Logical Ri ng Topology

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Ast ar t op ology is a LAN arch it ect ur e in w hich t he endp oint s on a n et wor k ar e conn ect ed t o a com mon cent realofhu b,t ing or sw it ch,t echn b y dedicat s. ical Log ical busk an ring stt op ologies are oft en Cov erag cut edge ologiesedliklink e opt n et wor ingd and or age im plem ent ed ph ysically in a st ar t opology , w hich is illu st r at ed in Figur e 2- 5 . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables Figu net w r eor 2 kin - 5g .p rAofessionals Logical t Tr o un eederst Topol and an ogy d imCa plem n en Con t cont t a in em por M uarltyi pl inteer Node net w orksing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP At r ee t opology is a LAN arch it ect ur e t h at is ident ical t o t h e bus t opology , except t hat br anches Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age w it h mu lt iple nod es ar e p ossible in t his case. Figur e 2- 5 illust r at es a log ical t ree t op olog y. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

LAN Devices Dev ices com mon ly used in LANs includ e r ep eat er s, hub s, LAN ex t ender s, br idges, LAN sw it ches, and r out er s. •

Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

NO TE

By Cisco Systems, Inc.

Repeat er s, hubs, an d LAN ex t en der s ar e discu ssed br ief ly in t h is sect ion. Th e fu nct ion and oper at ion of br idges, swit ches, and r out er s ar e discussed gener ally in Ch apt er 4, Pub Datr e: Sep 2 003 I OS Sof t w are, " an d Ch apt er 5, " Br idg in g and Swit chin g Basics. " " I nt odu cttem ionbert o1 1, Cisco

Pub lish er: Cisco Press

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Ar ep eat er is a ph ysical layer d ev ice used t o int er con nect t he media segm ent s of an ex t en ded net w or k. A r epeat er essen t ially en ables a ser ies of cable seg ment s t o b e t r eat ed as a sin gle cable. Repeat ers receiv e signals f r om one n et w or k segm en t an d am p lif y, ret im e, and r et ran sm it t hose sign als t o anot her net w or k segm ent . These act ion s pr event sig nal d et er iorat ion caused b y The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of long cable lengt h s and lar ge nu mb er s of conn ect ed devices. Repeat er s ar e incapab le of essent ial an d cu t t ing- edg e t ech nologies. per for m ing com p lex f ilt er ing and ot h er t raf fic p rocessing . I n addit ion, all elect r ical sign als, includin g elect r ical dist ur ban ces an d ot her er r or s, ar e repeat ed and am plified. Th e t ot al n um ber of r epCon eat er s and w or t s ties hatessen can be ed is limpr it ed d ue t oals t im g and ot her cise ov ernvetiew s kofsegm t echnen olog t ialconnect t o n et wor k ing ofession atinall lev els, f rom issu es. Figur e 26 illust r at es a r epeat er connect ing t w o n et w or k segm en t s. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of lik e opt n et wor k ing age e nt s Figu r ecut2t-ing 6 . edge A Ret echn peaologies t e r Conn ectical s Tw o Ne t wand or kst or Segm Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr ofbessionals oper at e. Tools andt hat gu id elines fsorm opt im izing pereach for mvance w ill incred ease Ahu is a ph ysical layer d ev ice connect ult iple user syst st atem ions, ia a dedicat cable. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient Elect rical int er connect ions ar e est ablish ed inside t he hu b. Hu bs ar e used t o cr eat e a ph ysical st ar decisions eiraint net w ork s. net w or k wfor hilet hm aining t h e logical bus or r in g con figu rat ion of t h e LAN. I n som e r espect s, a hu b f un ct ion s as a m u lt ip ort r ep eat er . ALAN ext end er is a r em ot e- access m ult ilay er sw it ch t hat con nect s t o a host r ou t er . LAN ext end er s f or w ard t r aff ic fr om all t he st and ar d n et w or k lay er pr ot ocols ( su ch as I P, I PX, and App leTalk ) an d f ilt er t raf fic b ased on t he MAC ad dr ess or n et wor k lay er pr ot ocol t y pe. LAN

ext end er s scale w ell becau se t he host r out er filt er s out unw an t ed br oad cast s an d m u lt icast s. How ev er , LAN ex t ender s ar e not capable of segm en t ing t r aff ic or creat ing secu rit y f ir ew alls. Figur e 2- 7 illust r at es m ult iple LAN ext end er s conn ect ed t o t h e host rou t er t hr ough a WAN.

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Figu r e 2 - 7 . M ul t ip le LAN Ext e n der s Can Conn ect t o t he Host Rou t e r Thr ou gh a W AN Table of Content s I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

Descr ibe t he t y pe of m edia access u sed by Et her net .

2:

I ndex ibe t he t y pe of m edia access u sed by Tok en Ring. Descr

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Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : Descr By Cisco Systems, Inc.ibe

u nicast , m ult icast , and br oadcast t r ansm issions.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Cisco' s w eb sit e (w w w .cisco. com ) is a w ond er f ul sour ce for mor e inf or mat ion ab out t hese t opics. The D ocu m en t at ion sect ion includ es in - dept h discussion s on man y of t he t opics cov ered •in t his chapt er Table . of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

• Tear e, Diane. Designing Cisco Net w or ks. I nd ianapolis: Cisco Pr ess, Ju ly 199 9. By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 3. Introduction to WAN Technologies • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Becom e f am iliar w it h WAN t er m inology .

By Cisco Systems, Inc.

Lear n about diff erent t y pes of WAN conn ect ions. Pub lish er: Cisco Press

Becom e ftem amber iliar h dif fer en t Pub Dat e: Sep 1 1,w2it003

t y pes of WAN eq uipm ent .

I SBN: 1- 58 705 -1 19 -2

This chap t er int r oduces t he var ious p r ot ocols an d t echn ologies used in w id e- area n et wor k ( W AN) Pages: 11 28 env iron ment s. Topics su mm ar ized h er e includ e point - t o- point lin ks, cir cu it sw it ching, packet sw it ch in g, v ir t ual cir cu it s, dialup ser v ices, and WAN devices. Chapt er s in Par t I I I , " WAN Pr ot ocols, " addr ess sp ecific t echnolog ies in m or e det ail.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

What Is a WAN? AWAN is a dat a comm u nicat ion s net w or k t hat cover s a r elat ively br oad geogr aph ic area and t hat of t en uses t r ansm ission facilit ies p rov ided by com mon car rier s, su ch as t elephon e com panies. WAN t echnologies g en er ally fu nct ion at t he low er t h ree lay er s of t he OSI r efer en ce •m odel: t h e phy Table of Content sical layer , st he dat a link lay er , and t he net w ork lay er. Figur e 3- 1 illust r at es t he •r elat ion sh ip bI ndex et w een t he com mon WAN t echn ologies and t he OSI m odel. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r eer:3Cisco - 1 . Press W AN Techn ologi es O pe r at e at t h e Low est Lev el s of t h e O SI Pub lish M ode l Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Point-to-Point Links Apoint - t o- poin t lin k p r ovides a sin gle, pr e- est ablished WAN com mu nicat ions pat h f r om t he cust om er pr em ises t hr ough a car r ier net w ork , such as a t eleph one com pany , t o a r em ot e net w or k. Point - t o- p oin t lines ar e usu ally leased f rom a car rier and t h us ar e of t en called leased •lines. For a poin Table t - of t o-Content point sline, t he car r ier allocat es pair s of w ir e and facilit y har dw ar e t o you r •line only . Th ese I ndex circu it s are generally p riced b ased on band wid t h requ ir ed and dist ance bet w een It he nt e rn or k ing Teed chnologie s HPoint a ndbook Four th lin Edit t wetowconnect p oint s. - t o-, point ksion are g en er ally m or e ex pensiv e t han shar ed ser vices such asSystems, Fr am e Relay By Cisco Inc. . Figur e 3- 2 illust r at es a t yp ical p oint - t o- p oin t link t hr ough a WAN. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Figu r e 3 - 2 . A Ty pi cal Poi nt - t o- Poin t Lin k O pe r at e s Thr ou gh a W AN t o a I SBN: 1- 58 705 -1 19 -2 Re m ot e N et w or k Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Circuit Switching Sw it ch ed cir cuit s allow dat a conn ect ions t hat can b e init iat ed w hen needed an d t er m inat ed w hen com mu nicat ion is com plet e. This w or ks mu ch lik e a n orm al t elephon e line w or ks for v oice com mu nicat ion . I nt egr at ed Ser v ices Dig it al Net wor k ( I SDN) is a g ood ex am ple of circuit •sw it ch in g. Wh Table s en aofr Content out er has d at a f or a rem ot e sit e, t he sw it ched cir cu it is init iat ed w it h t he •circuit num b er I ndex of t he r em ot e net w ork . I n t he case of I SDN cir cu it s, t he d ev ice act ually places a Icall nt e rn or kt ing chnologie H a ndbook ion cir cuit . Wh en t h e t w o n et w or k s ar e connect ed t oettwhe elepTehone nums ber of t h e, Four r emth otEdit e I SDN and autSystems, hent icat Inc. ed , t hey can t r ansfer dat a. When t he d at a t r ansm ission is comp let e, t h e call can By Cisco be t er m inat ed. Figur e 3- 3 illust r at es an ex am ple of t h is t yp e of cir cuit . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Figu r e 3 - 3 . A Ci r cui t - Sw it ch ed W AN Un der g oes a Pr oce ss Sim i la r t o Pages: 11 28 Tha t Use d for a Tel eph one Cal l

[ View full size im age]

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Packet Switching Packet sw it chin g is a WAN t echn olog y in wh ich user s shar e comm on carr ier r esour ces. Because t his allow s t h e carr ier t o m ak e m or e ef ficient u se of it s infr ast r uct ur e, t he cost t o t h e cust omer is gener ally mu ch b et t er t han w it h p oin t - t o- poin t lines. I n a pack et sw it ch in g set up , net w or ks hav e •connect ions int Table of Content o t he car r iers ' s net w or k, and man y cust om er s shar e t h e carr ier' s net w or k . The •carr ier can t hen I ndexcr eat e v ir t u al cir cuit s b et ween cu st om er s' sit es by w h ich pack et s of dat a are Ideliver nt e rn eted w orfkr ing chnologie H aher ndbook Fourhtht he Editnet ion w or k . The sect ion of t h e car r ier ' s net w or k t hat is om Te one t o t hes ot t hr,oug shar ed Systems, is of t en rInc. efer r ed t o as a cloud. By Cisco Som e exam ples of pack et - sw it ching n et w or k s include Asy nchr onou s Tran sfer Mode ( ATM) , Fr ame Pub lish er: Cisco Press Relay, Sw it ch ed Mu lt im egab it Dat a Ser v ices ( SMDS) , and X. 25 . Figur e 3- 4 sh ows an ex am ple Pub Dat e: Sep tem ber 1 1, 2 003 pack et - sw it ched cir cuit . I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 3 - 4 . Pa ck e t Sw it chi ng Tr an sfe r s Packe t s Acr oss a Ca r r ie r Ne t w or k The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.[ View full size im age] Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net wvor p rofnect essionals, egar of ex ise. The ir kin t ualg con ion s betr w eendless cust om er pert sit es ar e oft en r eferr ed t o as a v ir t u al circuit . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

WAN Virtual Circuits Av ir t ual circuit is a logical circuit creat ed wit h in a shar ed net w or k bet w een t w o net w ork devices. Tw o t y pes of v ir t ual cir cu it s exist : sw it ched vir t ual cir cuit s ( SVCs) and per man en t v ir t ual cir cu it s ( PVCs) . •

Table of Content s

•SVCs ar e v ir tIual ndexcir cu it s t hat ar e dy nam ically est ablished on d em and an d t er m inat ed w h en It rntansm e rn et w or k ingisTecom chnologie a ndbook Fourion th Edit ion an SVC consist s of t hr ee phases: circuit ission p let e.s HCom m un, icat ov er est ablish ment , dat a t r ansfer , and cir cuit t erm inat ion . The est ablishm en t p hase inv olv es creat ing By Cisco Systems, Inc. t he vir t ual cir cuit b et ween t he sour ce and dest inat ion devices. Dat a t ran sf er inv olves t r ansm it t ing dat a bet w een t he d ev ices over t h e vir t ual cir cuit , an d t he circuit t erm inat ion p hase Pub lish er: Cisco Press inv olves t ear ing dow n t he v ir t ual cir cu it b et w een t h e sour ce and dest in at ion devices. SVCs ar e Pub Dat e: Sep tem ber 1 1, 2 003 used in sit uat ions in w hich dat a t r ansmission b et ween devices is sp or adic, larg ely b ecause SVCs I SBN: 1- 58 705 -2 incr ease b andw idt-1 h 19 used due t o t he cir cuit est ablishm en t an d t er m inat ion phases, but t h ey Pages: 11 28 decrease t he cost associat ed w it h const ant vir t ual cir cuit availabilit y .

PVC is a per m anent ly est ablish ed v irt u al circuit t hat consist s of one m ode: d at a t r ansf er . PVCs ar e used in sit uat ions in w hich dat a t r ansfer bet w een dev ices is const an t . PVCs d ecr ease t he ban dw idt h use associat ed w it h t h e est ab lish ment and t er min at ion of v ir t ual cir cu it s, but t hey incr ease duion e t oofconst t v- irt ual cirallcu init av ailab . PVCs are generally conf cover igur edage b y of t he The u pdatcost ed sedit t he an b est selling one netilit w york ing r ef erence p rov ides ser v ice pr ovider w h en an or der is placed f or ser v ice. essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

WAN Dialup Services Dialup ser v ices of fer cost - effect iv e met h ods f or connect ivit y acr oss WANs. Tw o pop ular dialup im plem ent at ion s ar e dial- on- d em and r out in g ( D DR) and dial b ack up . •DDR is a t echniqu Table of Content s a r out er can dy nam ically init iat e a call on a sw it ch ed cir cu it w hen it ew hereby •needs t o sen Idndex d at a. I n a DD R set up, t he r out er is con figu red t o in it iat e t he call w hen cer t ain Icrit nt eer rn ia et war orek ing ndbook , Four ion w ork t raf fic n eedin g t o be t ran sm it t ed. When t he m etTe, chnologie such as saHpa art icular t ypthe Edit of net connect ion is mad e, t r affic passes ov er t he line. Th e r out er config ur at ion specifies an idle t im er By Cisco Systems, Inc. t hat t ells t he r out er t o dr op t he con nect ion w hen t he cir cu it has rem ained id le for a cer t ain per iod. Pub lish er: Cisco Press

Datup e: Sep berher 1 1, w 2 003 DialPub b ack is tem anot ay of conf igur ing DDR. How ev er , in d ial back up, t he sw it ch ed cir cu it is I SBN: 158 705 -1 19 -2 used t o pr ov ide b ack up ser v ice for an ot her t y pe of cir cu it , such as point - t o- p oint or pack et sw it chPages: in g. Th 11e 28r out er is conf ig ur ed so t hat w h en a failur e is det ect ed on t he pr imar y cir cu it , t he dial b acku p line is in it iat ed . The d ial back up lin e t hen su ppor t s t he WAN con nect ion un t il t he pr im ary cir cuit is r est or ed . When t his occur s, t he d ial back up con nect ion is t er m in at ed.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

WAN Devices WANs u se n um erou s t y pes of devices t hat ar e specif ic t o WAN en vir onm ent s. WAN sw it ches, access ser v ers, m odem s, CSU/ DSUs, and I SD N t er min al adap t er s ar e d iscussed in t he f ollowin g sect ions. Ot her dev ices f ound in WAN env iron m en t s t hat ar e used in WAN im plem en t at ions •include rou t er Table of Content s s, ATM swit ches, and m ult iplex er s. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

WAN Switch

By Cisco Systems, Inc.

Pub lish AWAN sw er: it chCisco is aPress m ult ipor t in t ern et w or k ing device used in car r ier n et w or k s. These devices Pub Dat e: Sep 2 003 t y pically sw it chtemsuber ch1 t1,r af fic as Fr ame Relay , X. 25 , and SMD S, and oper at e at t he d at a link lay er I SBN: 158 705 -1 19 -2 of t he OSI r ef erence m odel. Figur e 3- 5 illust r at es t w o r out er s at r em ot e end s of a WAN t hat ar e connect ed b11 y 28 WAN sw it ches. Pages:

Figu r e 3 - 5 . Tw o Rout er s a t Re m ot e End s of a W AN Ca n Be Conn ect ed byallWinAN s r ef erence p rov ides cover age of The u pdat ed edit ion of t he b est - selling oneSw netit w che ork ing essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Access Server pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. An access ser v er act s as a concent r at ion point for d ial- in and d ial- ou t conn ect ions. Figur e 3- 6 illust rat es an access serv er concen t r at ing dial- out con nect ion s int o a WAN.

Figu r e 3 - 6 . An Acce ss Ser v e r Con ce nt r at es D ia l- Ou t Con ne ct i ons i nt o a

W AN

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Modem

Con cise erice v iew s ofinttechn olog t o n etsignals, wor k ingenabling pr ofession als all tlev els, itf rom Am odem is a ov dev t hat er pr et s dies ig itessen al andt ial analog d at a tat o be r ansm t ed nov ice t o ex pert . ov er voice- gr ade t elep hone lin es. At t he sour ce, digit al sig nals ar e conv er t ed t o a for m suit ab le for t r ansmission ov er analog comm u nicat ion f acilit ies. At t h e dest in at ion, t h ese an alog signals New chapt s include e of eim3-por t ant rt at opics EAP ar e r et u r ned t o er t heir dig it alcov for erag m . Figur 7 illust es alike simVoI ple Pmand odem - t o- m odem connect ion t hr ou gh a WAN. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

A Mnologies od em Hand Conbook ne ct i on t hThEdr itoug W AN Ha nd lerefer s An al og I nFigu t ern etrweor3k -in7g. Tech , Four ion , his a a com pr ehensive ence t hat a nd gi and t al Sign ls en t cont em por ar y int er net w ork ing enables net w or kin g p r ofessionals t o unDi derst an d imaplem t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tCSU/DSU o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, g a /m or ealr ealist ic pict of t he realld nalet w virice onm ent st oinconnect w hich Achann el pr serovid viceinunit digit ser vice unitur( eCSU/ DSU) is waor digit inor t erk fing aceen d ev used pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease a r ou t er t o a digit al cir cu it lik e a T1 . The CSU/ DSU also pr ovides sign al t im in g for com m unicat ion pr ct ivtithyese an d imices. pr ov Figur e eff iciency, helpr at ing akeofmor in t elligent , cost - eff icient betodu w een dev e 3- 8 illust est he t her eader placemment t heeCSU/ DSU in a WAN decisions for t h eir net w ork s. im plem ent at ion .

Figu r e 3 - 8 . The CSU/ D SU St a n ds Be t w ee n t h e Sw it ch an d t he Te r m in al

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 11 28 ISDNPages: Terminal Adapter

An I SDN t er m inal ad apt er is a dev ice u sed t o con nect I SDN Basic Rat e I n t er f ace ( BRI ) connect ions t o ot her int er faces, such as EI A/ TI A- 2 32 on a r out er . A t er m inal ad apt er is essent ially an I SD N m odem , alt hou gh it is called a t er m inal ad apt er because it d oes not act u ally The uerpdat conv t analog ed edit t oion d igof it al t he signals. b est - selling Figur eall3- 9in-illust one rnet at es w ork t heing placem r ef erence ent ofptrov he ides t er min cover al adap age of t er in an essent I SDN ial env an diron cu tm t ingen tedg . e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom pert . Ter m i na l Ad apt er Con ne ct s t he I SD N Ter m i na l Ada pt e r Figunov r eice 3 -t9o .exThe

t o Ot he r I nt er f a ce s

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What ar e some t yp es of WAN circuit s?

2:

I ndex is DD R, and h ow is it d iff er ent fr om dial backu p? What

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Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : What By Cisco Systems, Inc.is 4:

a CSU/ D SU used f or ?

What is t h e diff er ence bet w een a m odem and an I SD N t er min al adap t er ?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Mahler, Kev in. CCNA Tr ain ing Guide . I nd ianapolis: New Rid er s, 19 99. •

Table of Content s

•• Cisco I OS Dial Solut ions. I nd ianapolis: Cisco Pr ess, 1 998 . I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco ISystems, • Cisco OS Wid eInc. Ar ea

Net wor k in g Solut ions . I nd ianapolis: Cisco Pr ess, 1 999 .

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 4. Introduction to Cisco IOS Software • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Under st and Cisco I OS sy st em ar chit ect ur e comp onent s.

By Cisco Systems, Inc.

Wor k w it h t he Cisco I OS Com m and Line I n t er f ace ( CLI ) an d com m on com m and s. Pub lish er: Cisco Press

Lear n Sep about Cisco OS Pub Dat e: tem ber 1 1, 2I003

t r ou bleshoot in g t echn iq ues.

I SBN: 1- 58 705 -1 19 -2

Under st and upg rad ing and r elease in for m at ion. Pages: 11 28

The Cisco I OS soft w ar e is net w or k syst em soft war e t h at r un s on Cisco r out ers and swit ches. I t is used t o conf ig ur e, m onit or , and t r oub leshoot t he sy st em .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

System Architecture Lik e a com pu t er , a r out er has a CPU t hat var ies in p er f orm ance an d capab ilit ies depend ing on t he rou t er plat for m . Tw o ex am ples of pr ocessor s t hat Cisco uses are t he Mot orola 680 30 and t he Or ion/ R4600 . The Cisco I OS soft w ar e r un ning in t he r out er r equir es t he CPU or pr ocessor t o •m ake rou t ingTable and ofbrContent idgin gs d ecisions, m aint ain rou t ing t ables, and ot her sy st em m an agement •fu nct ions. The I ndex CPU m ust h ave access t o d at a in m em or y t o mak e d ecision s or t o get inst r uct ions. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ther e arSystems, e usually By Cisco Inc.f our t y pes of m emor y on a Cisco rou t er : PubROM lish er:— Cisco Press ROM is

gener ally t he m emor y on a ch ip or m u lt ip le ch ips. I t is av ailable on a I t is read- on ly, wh ich m eans t h at dat a cannot be wr it t en t o it . The I SBN: in it 1-ial 58 705 sof-1t w 19ar -2 e t hat r uns on a Cisco r out er is called t he boot st r ap soft w ar e an d is usually Pages: 11st 28or ed in ROM. The b oot st rap soft war e is in vok ed w h en t h e rou t er boot s u p.

Pub Dat er e: 's Sepptem ber 1 1, 2boar 003 d. r out rocessor

Fla sh — Flash mem or y is locat ed on a p rocessor b oar d SI MM bu t can be ex pand ed using PCMCI A ( r em ov able) car ds. Flash m emor y is m ost com m only u sed t o st or e one or m ore Cisco I OS sof t w are im ag es. Configu r at ion f iles or sy st em infor m at ion can also b e copied t o Flash . On some high- end sy st em s, Flash m em or y is also u sed t o h old b oot st rap soft war e. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essentRAM ial an cu t t ingedg t ech nologies. —dRAM is ver y e fast mem or y t hat loses it s in for m at ion w h en t h e sy st em is r est ar t ed. I t is used in PCs t o st or e r unn ing applicat ions an d d at a. On a rou t er , RAM is u sed t o hold I OS syst em t ab les an d b uf fer s. RAM m em ory is basically used for all sy st em operat ion al st or age Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom r eq uir em ent s. nov ice t o ex pert . N V RA M— On t he r out er , NVRAM is used t o st or e t he st ar t u p conf igur at ion. This is t he New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP conf ig ur at ion file t hat I OS r eads w hen t he rou t er boot s u p. I t is ex t r emely f ast m em or y and is per sisteent across ebootts. Cov erag of cut t ing redge echn ologies lik e opt ical n et wor k ing and st or age Alt houAut ghhCPU m emor e r equir pon en tin s t net o ruwnorI OS, r out er I m also ored and by Cisco Syystar ems, w or ed ldwcom ide leader king af or t he n tust er n et . hav e v arious int er faces t o allow p ack et f or w ard in g. I nt er f aces ar e inp ut an d out pu t conn ect ions t o t h e rou t er tI hat car t hat nologies needs t oHand be r out ed, or swt h it ch . The m on t y pes of ence int erftaces n t ern et ries w or kdat in ga Tech book Four Eded it ion , ismost a comcom pr ehensive refer hat are Et h er n et and ser ial. Sim ilar t o t h e dr iver soft war e on a com p ut er w it h par allel p ort s and USB enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing por t s, I OS has dev ice dr iv er s t o sup por t t hese v ar ious int er face t y pes. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . All Cisco s havan ed a ucon sole ort t her ats pr ides itan TI A- 232 asynnet chrwonous ial Com plet er out w it er h new pdat ed pchapt onovsecur y , EI st A/ or age, opt ical or k in g,ser scalabilit y, connect ion. Th e console por t can be conn ect ed t o a com p ut er' s serial conn ect ion t o gain er mt oinal and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen ttial all access t o tghe r out er . Most rrou t ers alsoof hav e anise. aux iliar y por t t hat is ver y similar t o t he con sole net w or kin p rof essionals, egar dless ex pert por t , b ut is t y pically u sed for mod em con nect ion f or r em ot e r out er m an agement . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Ex 1 ot shocols, ows t he outinv p ut Cisco 640 r out er t h at ju st t ed. on haram dwple ar e,4-pr andconsole ser v ices olvofeda. new Fu ndam ent3al t ech nology infhoras mat ionbeen is prst ovarided Not ice t he p rocessor , int er f ace, an d m em ory in for m at ion t hat is list ed. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Exa m s,plpr e ovid 4 - 1in. gCisco 4 0 icRout pu t or a kt ing St ar t up syst em a m or e3r 6 ealist pict ureer ofConsole t he real- wO oru ldt n et w en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. System Bootstrap, Version 11.1(20)AA2, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1) Copyright (c) 1999 by Cisco Systems, Inc. C3600 processor with 98304 Kbytes of main memory

Main memory is configured to 64 bit mode with parity disabled

program load complete, entry point: 0x80008000, size: 0xa8d168 Self decompressing the image : ################################################# •

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#################################################################### [OK] • I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Restricted Rights Legend Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Use, Pages: duplication, or disclosure by the Government is 11 28 subject to restrictions as set forth in subparagraph (c) of the Commercial Computer Software - Restricted The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Rights clause at FAR sec. 52.227-19 and subparagraph essent ial an d cu t t ing- edg e t ech nologies. (c) (1) (ii) of the Rights in Technical Data and Computer Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Software at. DFARS sec. 252.227-7013. nov iceclause t o ex pert New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov eragCisco e of cutSystems, t ing edge tInc. echn ologies lik e opt ical n et wor k ing and st or age Aut h ored170 by West Cisco Sy st ems,Drive w or ldw ide leader in net w or king f or t he I n t er n et . Tasman I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat San Jose, California 95134-1706 enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com pletInternetwork e w it h new an dOperating u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Cisco System Software and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w (tm) or kin g3600 p rof essionals, dless of ex pert ise. IOS Softwarer egar (C3640-IS-M), Version 12.2(10), RELEASE SOFTWARE (fc2) Reader s w ill (c) obt ain a g reat er by un der st an ding of LANInc. and WAN n et w or k ing, p ar t icu lar ly t h e Copyright 1986-2002 Cisco Systems, har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of06-May-02 int egr al sy 23:23 st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Compiled Mon by pwade t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov eragtext-base: e is also ext end ed n ot only data-base: t o new n et wor k ing concep t s, but also t o old er , legacy Image 0x60008930, 0x610D2000 syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t(R4700) h eir net wprocessor ork s. cisco 3640 (revision 0x00) with 94208K/4096K bytes of memory. Processor board ID 17746964 R4700 CPU at 100Mhz, Implementation 33, Rev 1.0

Bridging software. X.25 software, Version 3.0.0. SuperLAT software (copyright 1990 by Meridian Technology Corp). 5 Ethernet/IEEE 802.3 interface(s) •

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1 Serial network interface(s) I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

DRAM configuration is 64 bits wide with parity disabled. By Cisco Systems, Inc.

125K bytes of non-volatile configuration memory. Pub lish er: Cisco Press

8192K bytes of ber processor board System flash (Read/Write) Pub Dat e: Sep tem 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

16384K bytes of processor board PCMCIA Slot0 flash (Read/Write) Pages: 11 28

--- System Configuration Dialog --The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Would you like to enter the initial configuration dialog? [yes/no]: Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP When a n ew r out er is fir st st ar t ed, I OS r uns an aut oin st all pr ocess w her ein t h e user is pr om pt ed t o answ ererag a few ion s. I OSt echn t h en ologies conf ig urlik ese topt he ical sy stnem based t hestin Cov e ofq uest cut t ing edge et wor k ingonand orput agepr ov id ed . Af t er init ial set up, t he conf igur at ion is m ost com mon ly mod ified u sin g t he com man d- line int er face ( CLI ) .Aut Othhored er w ay of conf ing t he ou t ide er inleader clu de HTTP net wf ork man bys Cisco Syigur st ems, w orr ldw in net and w or king or t he I nagement t er n et . app licat ions. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Cisco IOS CLI Cisco I OS h as t hr ee com man d m od es, each w it h access t o diff erent comm an d set s: U se r mTable od e— of This Content is st he fir st m ode a user has access t o aft er log ging int o t he r out er . The user m ode I ndexcan be ident if ied by t he > pr omp t f ollowin g t he r out er nam e. Th is mod e allows he user o chnologie ex ecut e sonly t he b, asic com mion ands, su ch as t h ose t hat sh ow t he sy st em' s st at us. I nt e rn tet w or k ing tTe H a ndbook Four th Edit The sy st em can not be conf ig ur ed or rest ar t ed f rom t his m ode. By Cisco Systems, Inc. • •

Priv i le ge d m ode — This m ode allow s users t o v iew t he sy st em con figu rat ion , r est ar t t he conf igur at ion mod e. I t also allow s all t h e com m and s t hat ar e available in Pub Dat e:mSep tem Pr berivileged 1 1, 2 003 m od e can b e ident ified by t h e # pr om pt follow ing t he rou t er nam e. user ode. The I SBN: u ser 1- 58m 705 od-1e19e-2na ble com m and t ells I OS t hat t h e user w ant s t o en t er pr ivileged mod e. I f an en able passw or d or en able secr et passw ord h as been set , t he user need s t o ent er t he Pages: 11 28 corr ect p assw or d or secr et t o b e gr ant ed access t o pr iv ileged m ode. An enable secret passw ord u ses st r onger encr yp t ion wh en it is st ored in t he conf ig ur at ion and, t herefor e, is safer . Pr ivileged m ode allow s t he user t o do an yt h ing on t he r out er , so it sh ould be u sed w it h cau t ion. To ex it pr iv ileg ed m ode, t h e user execut es t he di sa bl e com m and.

Pubsyst lish er: Press emCisco , and ent er

The uConfi pdat ed edit t hee— b est - selling in- one net wt ork p rov ides cover age of gur at ion i on of m od This m odeallallow s users o ming odifryefterence he r u nning sy st em essentconf ial an d cu t t ingedg e t ech nologies. ig ur at ion. To en t er config ur at ion m ode, ent er t he com man d confi gur e t e rm in al f r om pr iv ileged m ode. Conf igur at ion m ode h as var ious su bm odes, st art in g w it h global conf ig ur at ich olog can ies be ident hewor ( conf ig)pr # ofession p rom p t als f ollow inglev t hels, e r out er Con cise ovion er v mod iew s e, of wh t echn esseniftied ial tby o ntet k ing at all f rom nam e. As t h e config ur at ion m ode su bm odes chang e dependin g on w hat is being conf ig ur ed , nov ice t o ex pert . t he wor d s insid e t he par en t heses chan ge. For exam ple, w hen y ou ent er in t er f ace conf ur at ion bm ode, preomp t chan o ( conlike fig- if ) # Pf ollow ing t h e rou t er nam e. To New igchapt er s su include covt he erag of im por t ges ant tt opics VoI and EAP exit configu r at ion m ode, t he user can ent er e nd or pr ess Ct r l- Z. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Not e t h at in t hese m odes, en t er ing t h e cont ext - sensit ive com m and ? at any point sh ow s t he av ailab lehcom and s at tSy hat lev el. wTh ? can also beinused he mfidd com Aut oredmby Cisco st ems, oreldw ide leader net winortking or tleheofI nat er n etman . d t o show possible comp let ion opt ion s. Ex am ple 4- 2 sh ows t he u se of t h e ? com m and t o disp lay t he I n t ern com man et wds orav k inailable g Tech w nologies it hin a giv Hand en book com m , Four and tm h ode. Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st . Lear t o ng incorCon por at int -Sen er net wsi ortkin echn Exa mrypl e 4 n- 2how . Usi t ee xt i veg tH el polog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Router>? Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Exec commands: a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . access-enable Create a temporary Access-List entry Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich access-profile Apply user-profile to interface pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient clear Reset functions decisions for t h eir net w ork s. ...

The f ollow in g st eps in t r oduce y ou t o t h e com m and s used t o chang e comm an d m ode, v iew syst em inf or mat ion , and conf ig ur e a p assw or d. Real CLI out pu t f r om a Cisco 3 640 r out er r un ning Cisco I OS sof t w are is sh ow n. St e p 1 . En t er en abled m ode by ent er in g e na ble an d pr essing Ent e r:

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press

Router> enable Pub Dat e: Sep tem ber 1 1,

2 003

I SBN: 1- 58 705 -1 19 -2

Router#

Pages: 11 28

St e p 2 . To see w hich ver sion of I OS is ru nning on t he sy st em, en t er t he show v er sion com man d: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Router#show version Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Cisco Internetwork Operating System Software I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat IOS (tm) Software (C3640-IS-M), Version RELEASE (fc2) enables net3600 w or kin g p r ofessionals t o un derst and an d im12.2(10), plem en t cont em por arSOFTWARE y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Copyright (c) 1986-2002 by atCisco indu st ry . Lear n how t o incor por e int er Systems, net w or kin gInc. t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Compiled 23:23 and speed, Mon t h is 06-May-02 book is a com plet e by an dpwade u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Image text-base: 0x60008930, data-base: 0x610D2000 Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions ROM: System Bootstrap, Version DEPLOYMENT SOFTWARE t o en su re con cept comp r eh en sion and11.1(20)AA2, r et en t ion, and EARLY ad dit ional r esou r cesRELEASE f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy (fc1) syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Router uptime is 47 minutes System returned to ROM by reload System image file is "slot0:c3640-is-mz.122-10.bin"

cisco 3640 (R4700) processor (revision 0x00) with 94208K/4096K bytes of memory. Processor board ID 17746964 R4700 CPU at 100Mhz, Implementation 33, Rev 1.0 •

Table of Content s

Bridging software. • I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

X.25 software, Version 3.0.0. By Cisco Systems, Inc.

SuperLAT software (copyright 1990 by Meridian Technology Corp). Pub lish er: Cisco Press Pub Dat e: Sep tem ber802.3 1 1, 2 003interface(s) 5 Ethernet/IEEE I SBN: 1- 58 705 -1 19 -2

1 Serial interface(s) Pages: network 11 28 DRAM configuration is 64 bits wide with parity disabled. 125K bytes of non-volatile configuration memory. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of 8192K bytes of processor board System flash (Read/Write) essent ial an d cu t t ing- edg e t ech nologies. 16384K bytes of processor board PCMCIA Slot0 flash (Read/Write) Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Configuration is erag 0x2002 New chapt erregister s include cov e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age ored Cisco Sysee st ems, leader in net w er or king f or t Cisco he I n tIer n etsof . t w are, From Aut t hehou t putby , you can t h atwt or hisldw is ide a Cisco 3 640 r out r un ning OS Version 12. 2 ( 10) and t he sof t w are im ag e is locat ed on t he PCMCI A Flash car d in slot 0 . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables kin g, pcon r ofessionals uner derst andt oanbde im plem en ten cont arrat y int net w ork ingt he St net ep w 3 .orNext figu re t he troout n ame " I OS. " To t er em conpor figu ionerm ode, u se t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing com man d confi gur e t e rm in al : indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag econfigure is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Router# terminal syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu idone elines opt im izing emCNTL/Z. per for m ance w ill incr ease Enter configuration commands, perf orline. End syst with pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir hostname net w ork s. IOS Router(config)# IOS(config)#

Not ice t hat t he p rom p t chan ges t o " I OS" im mediat ely af t er you ent er t h e host na m e com m and. All conf ig ur at ion ch anges in Cisco I OS t ak e p lace im m ed iat ely . St e p 4 . Next , you need t o set t h e enable passw or d an d t he enable secret passw or d. The enable secr et p assw or d is st ored using st ron ger encry pt ion an d ov err ides t h e enable passw ord if it is con figur ed. To set bot h p assw or ds, y ou ent er t he f ollow ing : •

Table of Content s

•

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

IOS(config)# I SBN: 1- 58enable 705 -1 19 -2password cisco Pages: 11 28

IOS(config)#enable secret san-fran IOS(config)#exit IOS# The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. To g et int o enabled m od e, you need t o ent er t h e passwor d san - fr an . Th e e xi t com m and t ak es Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom y ou u p one level in t he con figu rat ion , or out of t he cu rr ent su bm ode. nov ice t o ex pert . St e pchapt 5 . Aft con figurcov ingerag t h e er out er por nam e ant opics d set tlike ing VoI t he Penand ableEAP and enable secr et New erer s include of im t ant passw ord s, you can ex am ine t h e r unn in g con figur at ion : Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, IOS# show running-config and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Building configuration... Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tCurrent o en su re configuration con cept comp r eh:en743 sion bytes and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst ! em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it12.2 y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient version decisions for t h eir net w ork s. service timestamps debug uptime service timestamps log uptime no service password-encryption

! hostname IOS ! enable secret 5 $1$IP7a$HClNetI.hpRdox84d.FYU. •

Table of Content s

enable password • I ndex cisco I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

! By Cisco Systems, Inc. ip subnet-zero Pub lish er: Cisco Press

!

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

call Pages: rsvp-sync 11 28 ! interface Ethernet0/0 The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of no ipialaddress essent an d cu t t ing- edg e t ech nologies. shutdown Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom half-duplex nov ice t o ex pert . !

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age interface Serial0/0 Autaddress h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . no ip I nshutdown t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing no fair-queue indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, ! and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g pEthernet2/0 rof essionals, r egar dless of ex pert ise. interface Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e no ip address har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions shutdown t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy half-duplex syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease ! pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. interface Ethernet2/1 no ip address shutdown

half-duplex ! interface Ethernet2/2 no ip address • •

shutdown

Table of Content s I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

half-duplex

By Cisco Systems, Inc.

! Pub lish er: Cisco Press

interface Ethernet2/3 Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

no ip address Pages: 11 28

shutdown half-duplex The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of ! essent ial an d cu t t ing- edg e t ech nologies. ip classless Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom ip http server nov ice t o ex pert . ip pim bidir-enable New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP !

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

dial-peer corbycustom Aut h ored Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . ! I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing line con 0 Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t echnologies. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . line aux Com plet e w0it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all line 4 essionals, r egar dless of ex pert ise. net w orvty kin g0p rof Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e ! har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions end t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals at e. Tools and id elines im izing em ur per illrrincr St e p 6 .oper The show r unni ng-gu confi g ouftor puopt t show s t h esyst config atfor ionmt ance hat iswcu entease ly act iv e pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient in t he sy st em ; how ev er , t his conf igur at ion is lost if t he sy st em is rest ar t ed . To sav e t h is decisions ork s. conffor ig urt hateir ionnet t owNVRAM, you m ust issue t he follow ing com man d:

IOS#copy running-config startup-config Destination filename [startup-config]? • Building configuration... Table of Content s •

I ndex

[OK] I nt e rn et w or k ing

Te chnologie s H a ndbook , Four th Edit ion

By Cisco Systems, Inc.

Pub lish er: Cisco Press

St e p 7 . To v iew t he st ar t u p con figur at ion saved in NVRAM, use t h e comm an d show

Pubst Dat Sep tem berfi1g. 1, 2 003 are:t upcon I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

I n t he pr eced in g st ep seq uence, not ice t he Et her net an d serial in t erf aces t hat sh ow up in t he conf ig ur at ion file. Each in t er f ace requ ir es t h at cert ain par am et er s such as encapsulat ion and add ress be set b ef or e t he in t er f ace can be used pr oper ly. I n ad dit ion, I P rou t ing or br idg in g m ight need t o be conf igur ed. Ref er t o t he Cisco I OS in st allat ion and conf ig ur at ion guides av ailab le at w w w .cisco. com f or y our v er sion of soft w ar e t o lear n about all possible conf ig ur at ion The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of opt ion s and r ecom m en ded g uidelines. essent ial an d cu t t ing- edg e t ech nologies. Table 4 - 1 d escr ibes som e of t h e m or e com m on comm and s used t o m onit or t he syst em . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Tab le 4 -1 . Com m a nd s Use d t o M on it or Ci sco I OS D ev ices

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Cisco I OS D e scri pt i on Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Com m a nd I nshow t ern etiw g Tech nologies bookst , at Four h d Edcon it ion , israt a ion comdet pr ehensive ntor e krfinace Display Hand s cur rent us tan figu ails f or allrefer int erence facest hat in t he enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing syst em t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing show ocesses s at CPU u ter ilizat e cu olog rr enties prin ocesses ru nnin in t he sy stent em. indu st rypr . Lear n how t o Display incor por e int net ion w or and kin g tthechn t o a LAN/ WANg env ir onm cpuplet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Com and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all show bu ff er s Show s h ow syst em b uff ers ar e cur r ent ly allocat ed and f unct ioning f or net w or kin g p rof essionals, r egar dless of ex pert ise. pack et for w ar ding Reader reat ers un dermstemor an ding LAN and n et wsy orst k ing, p ar laran ly dt hm e em ory show smweill m obt or yain a gShow h ow y isofallocat ed t oWAN v arious em fu nctt icu ions har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on ut ilizat ion a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions g cept compDisplay s detand ails ron har dw ar e card s in t he rsyst t oshow en su di re acon r eh en sion et en t ion, and ad dit ional esouem r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy show i p r out e Display s t he cur r ent act iv e I P r out in g t able syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich prshow of essionals Tools and gu cur id elines f orivopt izing systt oemMAC per for ancemwapp ill incr a rp oper at e. Display s t he r ent act e Iim P ad dr essaddmress in g ease in t h e pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient ARP t able decisions for t h eir net w ork s.

Debugging and Logging Cisco I OS sof t w are allow s f or det ailed d eb ugg in g for all p r ot ocols an d pr ocesses r un ning in t he syst em f or t r oubleshoot ing pu rp oses. Mor e inf or m at ion on debu ggin g can be ob t ained in t he Cisco I OS D eb ug Com m and Refer en ce, av ailable on w w w .cisco. com . •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

CAUTI ON

Pub lish er: Cisco Press

On ly Cisco I OS exp er t s sh ould enab le and disable de bug com m ands, b ecause t h ey can im pact and sh ould be u sed w it h car e. I mp rop er use m ight I SBN:t 1705 -1 19 -2inaccessible and in a f r ozen st at e in w hich n o pack et f orw ar din g t ak es leave h e58syst em place. Pages: 11 28

Pub Dat tem 1, f2orm 003 ance hav ee:a Sep sev erber e p1er

Sy st em m essag es are sh own on t he con sole an d can be enab led f or any session int o t he r out er . Dif ferent levels of sev erit y can be con figu red for diff er ent access m et h ods int o t he rou t er . Th e The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of eight m essage sever it y lev els are as follow s: essent ial an d cu t t ing- edg e t ech nologies. Em er ge ncy ( se v er it y 0 ) — The syst em is u nusable Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov o ve ex pert Al erice t ( tse ri t y .1 ) — I m m ediat e act ion is need ed New chapt erve s include covCrerag e of por Crit ical ( se ri t y 2 ) — it ical conim dit iont ant t opics like VoI P and EAP Cov erag e vofercut edge t echn Err or ( se it yt ing 3)— Er ror con ologies dit ion lik e opt ical n et wor k ing and st or age Aut ored Sy4st) ems, w oring ldwcon idedit leader W arh ni ng by ( seCisco v er it y — Warn ion in net w or king f or t he I n t er n et . I n t ernNetotwior k int g Tech nologies book ,alFour h Ed it ion , is a dit com pr ehensive refer ence t hat fi ca i on ( se ve ri t y 5Hand ) — Norm b ut tsig nificant con ion enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. erl t( he m s, t s, m t echn ologies, an de devices used in t oday ' s net w ork ing I nf orm aMast t iona sevt er e rit y 6con ) —cep I n for at ional m essag indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet w it hing new( se anve d ri u pdat er sing on m secur it y , st or age, opt ical net w or k in g, scalabilit y, Dee bugg t y 7 ed ) —chapt Debugg essage and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net wlog The or kin ginggpcom rof essionals, m and dir ect r egar s t he dless outof putext pert o v arise. ious t er m in als at t ached t o t h e sy st em or v irt ually connect ed, such as Teln et sessions. Ex am ple 4- 3 sh ows how t h e log gin g com m and can b e used Reader ill obt g reat er elunofder st an ding of and t o det ersmwine t h eain sevaerit y lev t he m essag esLAN show n . WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tExa o enm su pl re e con4cept r eh en sion and r et en - 3 . comp log gin g Com m an d t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient IOS(config)#logging ? decisions for t h eir net w ork s. Hostname or A.B.C.D

IP address of the logging host

buffered

Set buffered logging parameters

console

Set console logging level

exception

Limit size of exception flush output

facility

Facility parameter for syslog messages

history

Configure syslog history table

host

Set syslog server host name or IP address

•

Table of Content s

•monitor

I ndex

Set terminal line (monitor) logging level

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc. on

rate-limit Pub lish er: Cisco

Press

Pub Dat e: Sep tem ber 1 1, 2 003

source-interface

I SBN: 1- 58 705 -1 19 -2

Enable logging to all supported destinations Set messages per second limit Specify interface for source address in logging

Pages: 11 28 transactions

trap

Set syslog server logging level

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu IOS(config)# logging t t ing- edgconsole e t ech nologies. ?

Logging severity level Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . alerts Immediate action needed (severity=1) New chapt er s Critical include covconditions erag e of im por t ant t opics like (severity=2) VoI P and EAP critical Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age debugging Debugging messages (severity=7) Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . emergencies System is unusable (severity=0) I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat errors conditions (severity=3) enables net w or kin g pError r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing guaranteed messages indu st ry . Lear n howGuarantee t o incor por console at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, informational Informational messages and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence(severity=6) t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. notifications Normal but significant conditions (severity=5) Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Warning (severity=4) harwarnings dw ar e, pr ot ocols, and ser vconditions ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient En abling afor h igt hher of m decisions eir lev netel w ork s.essages show s all low er - lev el m essages as w ell. The d eb ugg in g level, or level 7 , show s all m essag es. Sy st em messages m ay also be b uff ered and seen using t he show l oggi ng com m and in pr iv ileged m ode. A user m ay also sen d logg ing m essages t o a syslog ser v er using t he log gin g host com m and in con figu rat ion m ode. A sy slog ser ver can be conf ig ur ed on a UNI X d ev ice or PC t o accep t t h ese m essag es f r om a r out er and place t hem in a file. This allow s f or lar ge f iles cont ainin g sy st em messag es t o b e m ain t ained, b ecause y ou are

not r est r ict ed by t he am oun t of m emor y on t h e r out er.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Reloading and Upgrading A sy st em rest ar t on Cisco r out er s is called a r eload. I f t he rou t er need s t o be r eload ed f or any r eason, t he re l oa d com m and needs t o be ent er ed f rom pr ivileged mod e, as show n in Ex am ple 44. Th e re l oa d com m and also allow s a t im e t o be set so t hat t he syst em r est art s aft er t h e •specif ied t im e Table Content s expof ires. •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Exa m Systems, pl e 4 - 4Inc. . Sy st em Re load O pt i ons Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

IOS#reload ? 705 -1 19 -2 I SBN: 1- 58 Pages: 11 28

LINE

Reason for reload

at

Reload at a specific time/date

cancel Cancel pending reload The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent cu t t ing-after edg e ta echtime nologies. in ial an dReload interval

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

The sy st em can also e reloaded by sw it ching it opt of f ical and nt et hen again. Cov erag e of cut bt ing edge t echn ologies lik e worback k ingon and st or age The con at ion eg ist er u sed w t oorsp ecify he r outin er net 's bwehoravior ur ing r eloading pr ocess. Autfigur h ored by rCisco Sy is st ems, ldw ide tleader king df or t he tIhe n t er n et . I t d et er m ines w het her t he I OS im age shou ld be load ed , det er min es w h et h er t erm inal access par amet etweror s kar rov ided, an d Hand en ables disables Esc . The igur atrefer ion rence eg ist er can be I n t ern ineg pTech nologies bookor, Four t h Edt he it ion , iskey a com pr conf ehensive t hat m odified in conf igur at ion m ode u sing t h e confi gre gist e r com m and. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all CAUTI ON net w or kin g p rof essionals, r egar dless of ex pert ise. Use t he confi gister e r un com only of if LAN y ou com elyn et und erksting, andpitars teff Reader sw ill obt aing-are g reat dermstand an ding and plet WAN w or icuect lars. ly t h e I ncor se of tand his comm an dinv can he sy ent st em accessible. har dw ar e, rect pr otuocols, ser v ices olvm edake . Futndam al in t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy By , tovid h e rin out ies t oicb pict oot ur f r om st im boaren d vir syonm st ement Flash, systdef emault s, pr g er a mfirorste trr ealist e oft he t hefirrealw age or ld in n ett he w oron k ing s in wifhich av ailab le, an d t hen it t r ies t he PCMCI A Flash car ds. The u ser m ay also specify w h ich im ages or pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease locat ions t o at t emp t b oot ing fr om an d t h e or der using t he boot sy st em com m and in pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient conf ig ur atfor ion t mod decisions h eir e: net w ork s.

IOS(config)#boot system slot0

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This causes tIhe sy st em t o at t em pt boot in g f r om an imag e in t he Flash m emor y in PCMCI A slot 0 • ndex befor e g oing t o t h e onb oard syst em, Four Flash. I nt e rn et w or k ing Te chnologie s H a ndbook th Edit ion By To Cisco u pgrSystems, ad e t he Inc. Cisco

I OS sof t w ar e v er sion r un ning on a r out er , y ou m ust f ir st det er m ine t h e r ight imag e t o upg rad e t o u sin g t h e up gr ade plan ners available on w w w .cisco. com . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 CAUTI ON

At t em pt ing t o load an incor r ect im age for y our sy st em m ig ht leav e t he sy st em inaccessible. Ensur e t h at y ou hav e t he cor r ect soft w ar e im age and m eet t he RAM an d Flash m emor y r equir ement s t o r un an d st or e t h e imag e befor e inst alling. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The copy com m and copies an im age in t o Flash m em ory . Th er e ar e m any way s t o do t his, as Conrcise v iew of 4t echn dem onst at edov inerEx am sple 5. olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Exa m pl e 4 - 5 . Opt ion s for Copy in g an I OS I m a ge in t o Fla sh M em or y Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . IOS#copy ? I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat /erase destination system. enables net w or kin g p rErase ofessionals t o un derstfile and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing flash: system indu st ry . Lear n how t oCopy incorfrom por at eflash: int er netfile w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, ftp: Copy from and speed, t h is book is a com plet eftp: an d ufile p- t o- system d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. null: Copy from null: file system Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e harnvram: dw ar e, pr ot ocols, and v ices nvram: inv olv edfile . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Copyserfrom system a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o pram: en su re con cept comp r eh en sion pram: and r etfile en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Copy from system Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e rfrom ealist ic pict ur e of system t he real- w or ld n et w or k ing en vir onm ent s in w hich rcp: Copy rcp: file pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e efffrom iciency, help ingsystem t he r eader m ake mor e in t elligent , cost - eff icient running-config Copy current configuration decisions for t h eir net w ork s. slot0: Copy from slot0: file system slot1:

Copy from slot1: file system

startup-config

Copy from startup configuration

system:

Copy from system: file system

tftp:

Copy from tftp: file system

xmodem:

Copy from xmodem: file system

ymodem:

Copy from ymodem: file system

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

The m ost com m on m et h ods ar e TFTP an d FTP. Af t er t he f ile has b een placed on y our TFTP or FTP ser v er, en t er t he copy com m and fr om p r iv ileg ed m ode an d answ er t he qu est ions on ser ver I P Pub lish er: Cisco Press add ress and sour ce and dest inat ion filenam es. Af t er you specify w hich imag e t he sy st em sh ould Dat e: tSep ber 1sy 1, st 2 003 loadPub using he tem boot em com m and, a re l oa d is requ ir ed for t he new v ersion of I OS t o be I SBN: 158 705 -1 19 -2 boot ed. Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary This chap t er int r oduced t he f und ament als of Cisco I OS soft w ar e, t he operat in g sy st em t hat ru ns on Cisco r out ers and swit ches. Cisco I OS sof t w ar e ru ns on a CPU and r eq uir es sev er al t yp es of m em or y t o st ore t he im age, conf ig ur at ion, r un ning app licat ions, an d dat a. Th e CLI is t he m ost •com mon m etTable of Content s hod used t o config ur e, mon it or , and t r oubleshoot a syst em r un ning Cisco I OS •soft w ar e. TheI ndex sof t w are pr ovides com pr ehensiv e d eb ugg in g and logging capabilit ies. You can Iup nt gr e rnade et w or Te w chnologie s H a ndbook , Four th Edit ion t hkeingsoft ar e im age by dow nloading it usin g one of m any op t ions and t h en f ollow ing a serCisco ies of sim p le Inc. st eps. By Systems, Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What ar e t he four main m emor y t y pes in a r out er ?

2:

I ndex ar e t he t hr ee Cisco I OS com man d mod es? What

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Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : What By Cisco Systems, Inc.is

t h e pr ocess of r est ar t ing a Cisco I OS sy st em called ?

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Cisco I OS soft w ar e Release 1 2. 2 docum ent at ion: w w w .cisco. com / pcgibin/ Suppor t / b r owse/ psp_ view .p l?p= Soft w ar e: I OS: 12. 2 &s= Docum ent at ion. •

Table of Content s

•

I ndex

•I nt Cisco r at ion sFund am ent als th , Cisco Pr ess, 1 997 , I SBN 06 410 491 29. e rn et IwOS or k Conf ing Teigu chnologie H a ndbook , Four Edit ion By Cisco Systems, Inc.

• Cisco I OS in a Nut shell , O'Reilly & Associat es, I n c. , 2 001 , I SBN 15 659 294 2X. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

• I n side Cisco I OS Sof t w ar e Archit ect ur e, Pear son Educat ion, 2 000 , I SBN 15 787 018 13. I SBN: 1- 58 705 -1 19 -2

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 5. Bridging and Switching Basics Obj e ct i ve s • •

Table of Content s

Lear n about diff erent LAN pr ot ocols. I ndex

I nt e rn Lear et w ornk ing Te chnologie a ndbook Edit ion about t he d iffserHent met,hFour odsthused to

deal w it h m edia cont ent ion .

By Cisco Systems, Inc.

Lear n about diff erent LAN t opologies. Pub lish er: Cisco Press

This chap t er int r oduces t he t echn ologies em ploy ed in dev ices loosely r efer r ed t o as br idges an d Dat e: Sep tem ber 1 1, 2 003 sw itPub ch es. Top ics sum m ar ized her e include general lin k layer d ev ice operat ion s, local and rem ot e I SBN: 1- 58sw 705it-1ch 19in -2g, an d LAN sw it ch ing. Chapt er s in Par t V, " Br idg in g and Swit chin g, " br idg in g, ATM Pages: 11 28 add ress specif ic t ech nologies in m or e d et ail.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

What Are Bridges and Switches? Br id ges an d sw it ches ar e d at a com m unicat ions d ev ices t hat op er at e pr in cip ally at Lay er 2 of t he OSI r efer en ce mod el. As su ch, t h ey ar e w idely r ef err ed t o as d at a link lay er dev ices. •Br idges becam Table of Content s e com m er cially av ailab le in t h e early 1 980 s. At t h e t ime of t heir int r oduct ion, •br idg es conn Iect ndex ed and enabled packet for w ard ing bet w een hom ogeneous net w ork s. Mor e Ir nt e rn etlyw,orbr k ing chnologie s H adiff ndbook , Four Edit ecent idg Te in g bet w een erent netth w or ksion has also been defined and st andar dized. By Cisco Systems, Inc.

Sever al k inds of b rid ging hav e pr ov en im por t ant as int er net w or kin g d ev ices. Tr anspar ent br idgin g is foun d p r im ar ily in Et her net env iron m en t s, w hile sour ce- r out e br id ging occur s Pub lish er: Cisco Press pr im arily in Tok en Rin g env ir onm en t s. Tr anslat ional b ridging p r ovides t r anslat ion bet w een t he e: dSep temsit ber pr 1 1,inciples 2 003 for mPub at sDat an t ran of diff er ent m ed ia t y pes ( usually Et hern et and Tok en Rin g) . I SBN: 158 705 -1 19 -2 Finally, sour ce- r out e t r anspar en t b ridging com bines t h e algor it hm s of t r anspar ent br idging an d sour cePages: r out e 11 28 br idging t o en able com mu nicat ion in m ixed Et h er net / Tok en Rin g en vir onm ent s. Today , sw it ching t ech nology h as emer ged as t he ev olut ionar y heir t o br idging - based int er net w ork ing solut ions. Sw it ching im plement at ion s now dom inat e ap plicat ion s in w h ich br idg in g t echn ologies wer e im plement ed in pr ior net w ork desig ns. Super ior t hr oug hpu t per for m ance, high er por t d en sit y , low er per - por t cost , and g reat er f lex ibilit y hav e cont r ibut ed t o The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t he em er gence of sw it ches as r eplacem ent t ech nology f or br idg es an d as com p lem ent s t o r out ing essent ial an d cu t t ing- edg e t ech nologies. t echnology . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Link Layer Device Overview Br idging and sw it ching occu r at t he link lay er , w h ich cont r ols dat a flow , h andles t r ansm ission err or s, pr ov ides phy sical ( as opp osed t o log ical) addr essing , and m anages access t o t he p hy sical m ed ium . Br idges pr ov ide t h ese f unct ions by using v ariou s lin k layer p rot ocols t h at d ict at e •specif ic flow con Tablet rol, of Content er r or shan dling, addr essing , and m ed ia- access algor it hm s. Ex amp les of •pop ular link lay I ndex er pr ot ocols in clu de Et hern et , Token Ring , and FDDI . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Br and sw itInc. ch es are not com plicat ed d ev ices. Th ey an alyze in com ing f ram es, m ake By idges Cisco Systems, for w ar ding decision s based on inf or mat ion cont ained in t he f ram es, and for w ar d t he f ram es t ow ar d t he dest inat ion. I n som e cases, such as sour ce- r out e b r id ging , t he ent ir e p at h t o t h e Pub lish er: Cisco Press dest inat ion is cont ained in each f r ame. I n ot her cases, su ch as t r anspar ent br idgin g, f ram es ar e Dat e: Sep tem ber 1 1, 2 003 for wPub ar ded one hop at a t im e t ow ar d t he d est inat ion . I SBN: 1- 58 705 -1 19 -2

Upper Pages: - layer11p28 rot ocol t ran sp arency is a pr im ary ad van t age of b ot h br idging and sw it ching. Becau se bot h device t y pes op er at e at t he link lay er , t hey ar e not r eq uir ed t o ex am ine u pper lay er in for m at ion. Th is means t hat t hey can r apid ly for w ar d t r af fic r epr esent ing an y net w ork lay er p r ot ocol. I t is not uncom m on for a br idge t o m ov e AppleTalk, DECn et , TCP/ I P, XNS, an d ot her t r af fic b et w een t wo or m or e net w or ks. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Br idges ar e capable of f ilt er ing fr am es based on an y Lay er 2 f ield s. For ex am ple, a b rid ge can be essent ial an d cu t t ing- edg e t ech nologies. pr ogr am m ed t o r ej ect ( not for w ar d) all fr am es sou rced fr om a par t icu lar net w or k. Because link lay er in for m at ion of t en in clu des a r efer en ce t o an upp er - lay er pr ot ocol, br idges u su ally can filt er on t his p aram et er. Fu rtsherm or e,olog filt er s can b et ial helpfu dealin wofession it h un necessary oadcast and Con cise ov er v iew of t echn ies essen t o nletinwor k inggpr als at all br lev els, f rom m ult icast pack et s. nov ice t o ex pert . By divNew idingchapt lar ge w or k s int self-econt ain edt ant un itts, br idges an dPsw it ches ernet s include covoerag of im por opics like VoI and EAPpr ov id e sev eral adv ant ag es. Because only a cer t ain percent ag e of t r aff ic is for w ar ded, a br idge or sw it ch dim inishes t hee tof rafcut fic tex byologies dev iceslikon all ical connect ed segm ent s.stThe br id ge or sw it ch Cov erag ingperienced edge t echn e opt n et wor k ing and or age w ill act as a fir ew all for som e pot en t ially d amag ing net w ork er r or s and w ill accom m odat e com mu Aut nicat h ored ion by b etCisco w eenSy a st larems, ger num w or ldw b er ide of dleader ev icesint han net w wor ould kingbef or supp t heorI nt ed t er on n et any . sing le LAN connect ed t o t he br id ge. Br idges and sw it ches ex t end t he ef fect ive leng t h of a LAN, perm it t ing n t ern w or ken intgof Tech Handt book , Four ion , isper a com ehensive refer ence t hat tI he at tet achm d istnologies an t st at ions hat was nott hprEd evitiously mit tpr ed. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Alt hou gh br idges Mastand er t sw he itt er ches m s,shcon ar ecep most t s, trechn elevan ologies, t at t riban utdes, devices sev er al used d istin in ct t oday ion s ' diff s net erent w ork iat ing e tindu hesest try echnologies. . Lear n how Br t oidincor ges ar por e at gener e int ally er net u sed w or kin to g segm t echn entolog a LAN ies inint t oo aa LAN/ couple WAN of env sm aller ir onm ent . Commplet seg en tes.wSwit it h new ches an ar de ug pdat en er ed allychapt usedert os on segsecur m en titay ,lar stgore age, LAN opt in t oical m any net wsm oraller k in g, segm scalabilit ent s.y, and Br idges speed, gener t h is ally book havis e only a com a plet fewepor an tds ufor p- tLAN o- d atconnect e r ef er ence ivit y , tw o ht er heeas t opswit ics tches hat are g enessen er allyt ial havt oe all net m any w or . kin Smgallp rof sw essionals, it ch es su chr egar as t hdless e Cisco of ex Cat pert alyise. st 29 24XL h ave 2 4 p or t s capable of cr eat in g 2 4 dif fer en t net w or k seg m en t s for a LAN. Lar ger sw it ch es su ch as t h e Cisco Cat aly st 65 00 can h ave Reader s wof ill pobt a gitreat ercan un der st an and k ing, p armt icu lar ly t hex e am ple, hu ndr eds ortain s. Sw ches also beding usedoft oLAN conn ect WAN LANsnwetitwhordiff erent ed ia—for har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov on a 1 0- Mb ps Et hern et LAN and a 1 00- Mbps Et her net LAN can b e connect ed u sin g a swit ch.ided Some a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions sw it ch es su ppor t cu t - t hr oug h sw it ching, w hich r educes lat ency and delays in t h e net w or k, w hile tbr o idg en su con cept r eh and en sion en fic t ion, ad dit ional r ces fror rt her st udy . on es re sup por t oncomp ly st ore- forand w ar dr ett raf swand it ching . Fin ally ,r esou sw it ches ed fu uce collisions Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy net w or k seg ment s becau se t hey pr ov ide dedicat ed bandw id t h t o each n et w or k segm en t . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Types of Bridges Br idges can be gr oup ed int o cat egor ies b ased on var ious p r oduct ch aract er ist ics. Using one pop ular classificat ion schem e, br idges ar e eit her local or r emot e. Local br idges p r ovide a dir ect connect ion bet w een mu lt iple LAN segm ent s in t h e sam e ar ea. Rem ot e br idges con nect m ult iple •LAN segm entTable s in dofif Content fer en t sar eas, usually ov er t elecomm u nicat ion s lines. Figur e 5- 1 illust r at es •t hese t w o con I ndex figur at ion s. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 5 - 1 . Loca l a n d Rem ot e B r idge s Con ne ct LAN Se gm e nt s i n Specif ic Ar e as Pub Dat e: Sep tem ber 1 1, 2 003

Pub lish er: Cisco Press

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Rem ot e br idg in g pr esent s sever al u nique in t er n et w or k in g ch alleng es, on e of w hich is t h e Autce h ored by Cisco or ldws.ide net w kingWAN f or tthe I nolog t er n ies et . n ow ar e dif fer en b et ween LAN Sy an st d ems, W AN w speed Altleader houg h in sever alor f ast echn est ablish in g a pr esence in geogr aph ically disper sed int er net w ork s, LAN speed s ar e oft en m uch I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat fast er t h an W AN speed s. Vast dif fer en ces in LAN an d WAN speed s can pr ev ent user s f rom enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing r unn ing delay- sensit ive LAN app licat ions over t h e WAN. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu n how t o incor e int er w orbkin t echn olog iespensat in t o aeLAN/ WAN env ir onm ent . Rem st otry e .brLear idg es can not im pr por ov eatWAN spnet eeds, ut gt hey can com f or speed discrepan cies Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, t hr ou gh a suf ficien t bu ff er ing capabilit y . I f a LAN dev ice capab le of a 3 - Mbps t r ansmission r at e and t hmu is book is wa itcom d uap-rem t o- d r ef ertence t o tbhe t op t hat are essen t o all w antspeed, s t o com nicat e h a plet dev eiceanon otat e eLAN, he local ridg e ics m ust r egulat e t het ial 3 - Mbps net w or kin g p rof essionals, r egar dless of ex pert ise. dat a st r eam so t hat it does n ot ov erw h elm t he 64 - kb ps serial lin k. This is don e by st or ing t he incom ing dat a in on boar d b uf fers and send ing it ov er t he ser ial lin k at a r at e t hat t he ser ial link Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e can accom m odat e. This b uff erin g can be achiev ed only f or shor t b ur st s of dat a t hat do not har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on ov er w helm t h e br idge's buf fer ing cap abilit y. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tThe o enI su cept comp r eh r etEn engineers t ion, and ad ditdif ional r esou r ces fu rtlin her st udyint . o n stre it ucon t e of Elect rical anen d sion Electand r onic ( I EEE) fer en t iat es t hef or OSI k layer Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy t w o separ at e sub lay er s: t he Media Access Con t r ol ( MAC) su blayer an d t he Logical Lin k Con t rol syst emsu s,blayer pr ovid. in g aMAC m or su e rblayer ealist icp pict of t he real- w ores ld m n et w oraccess, k ing en such vir onm s in hich ( LLC) The er mur it se and or chest r at edia asent cont entwion pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease and t ok en p assing , w hile t he LLC sublay er deals w it h fr am in g, f low cont r ol, err or con t rol, and pr odusublay ct iv it yeranaddr d imessing pr ov e .eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient MAC decisions for t h eir net w ork s. Som e br idges ar e MAC- layer b ridges, w hich br idge bet w een hom ogeneous n et w or k s ( f or exam ple, I EEE 8 02. 3 and I EEE 8 02. 3) , w hile ot her b ridg es can t r anslat e b et w een d iffer ent lin k lay er p r ot ocols ( f or ex amp le, I EEE 802 .3 an d I EEE 802 .5 ) . The b asic mechanics of such a t r anslat ion are show n in Figur e 5- 2 .

Figu r e 5 - 2 . A M AC-Lay er Br idg e Con ne ct s t he I EEE 8 0 2 .3 a nd I EEE 8 0 2 .5 N et w or k s

•

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet it h new anan d uI pdat chapt er s( on secur it y m , st or age, ical net w orcon k int g, scalabilit Figur e 5-e2willust r at es EEE ed 80 2. 3 h ost Host A) for ulat ing aopt packet t hat ains ap plicaty,ion and speed, h is book is a com an d u p-int oe r ef8er ence t o tpat he ib t op t hat aret ran essen ialert ot he all inf orm at ion tand encapsulat ingplet t h ee packet and at I EEE 02. 3- com le ics fr am e for sit tov net w or kin 3g p pert ise.t he fr am e is st r ipped of it s I EEE 80 2. 3 header I EEE 8 02. mrof edessionals, iu m t o t her begar ridgdless e. At of t h eexbr idge, at t he MAC sublay er of t he link lay er and is sub sequ en t ly passed up t o t he LLC sublay er for Reader ill obt ain Aft a ger reat unocessin der st ang,ding LAN WAN nback et w ordkow ing, lar ly80t h2.e5 fu r t her sprwocessing. t her is pr t h e of pack et and is passed n tpo ar ant icu I EEE har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is ission pr ov ided im plem ent at ion , w hich en cap su lat es t he pack et in an I EEE 802 .5 h ead er f or t r ansm on ton he a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions I EEE 8 02. 5 net w or k t o t h e I EEE 80 2. 5 host ( Host B) . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov e is also ext end edw een n ot only o knew et wor k ing concep t s, er but also old erse , legacy A b rerag id ge's t ran slat ion bet net wtor s of ndiff er ent t y pes is nev p er f ectt obecau one net w or k syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm likely w ill supp ort cer t ain fr am e f ields an d pr ot ocol fu nct ions not supp ort ed by t heent ot hserin w hich pr oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease netofwessionals or k. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Types of Switches Sw it ch es ar e d at a link lay er dev ices t hat , like b rid ges, en able m ult iple p hy sical LAN seg ment s t o be in t er conn ect ed in t o a sin gle lar ger net w or k. Sim ilar t o br idges, sw it ch es f or w ard and f lood t r aff ic based on MAC add r esses. An y net w or k device w ill creat e som e lat ency. Sw it ch es can use •dif fer en t f orwTable s ues—t wo of t hese ar e st ore- an d- for w ar d sw it ching and cut - t hr ough ar dinofgContent t echniq •sw it ch in g. I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

IByn st or e-Systems, an d- f orw ar d sw it ching , an ent ir e fr am e m ust be r eceived befor e it is for w ar ded. Th is Cisco Inc. m ean s t hat t he lat en cy t hr ough t h e sw it ch is r elat iv e t o t he f ram e size—t he lar ger t h e fr am e size, t he long er t he delay t h rou gh t he sw it ch. Cu t - t hr ough sw it ching allow s t h e swit ch t o begin Pub lish er: Cisco Press for w ar ding t h e fr am e w hen en ough of t he fr am e is r eceived t o m ak e a f or w ard in g decision. Th is Pub Dat e: Sep tem ber 1 1, 2 003 r ed uces t he lat ency t h rou gh t he sw it ch. St or e- and- for w ard sw it ching giv es t he sw it ch t h e SBN:y 1-t o 58 evaluat 705 -1 19 -2e t he f r ame f or er ror s b ef or e for w ar ding it . This cap abilit y t o n ot f orw ar d opp ort Iunit Pages: 28 fr am es cont11 aining er ror s is on e of t he ad van t ages of sw it ch es over hu bs. Cu t - t hr oug h sw it ching does n ot of fer t his ad van t age, so t he sw it ch m ight for w ar d fr am es con t aining err or s. Many t yp es of sw it ch es ex ist , inclu ding ATM sw it ches, LAN sw it ches, and v ar iou s t y pes of WAN sw it ches.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of ATM Switch essent ial an d cu t t ing- edg e t ech nologies. Asyn ch ron ous Tr ansf er Mode ( ATM) sw it ches p r ovide high- speed sw it ching an d scalable ban dw idt hs t here vwiew or kg rou p, t holog e enies t erpessen rise net d t he wals ideatarall ea.lev ATM Con ciseinov s of t echn t ialwt or o nk etback wor bone, k ing pran ofession els, f rom sw it chnov es ice su ppor t voice, vid eo, and dat a applicat ions, and ar e desig ned t o sw it ch f ixedsize t o ex pert . inf orm at ion un it s called cells, w hich ar e u sed in ATM com mu nicat ion s. Figur e 5- 3 illust r at es an ent er pr ise chapt n et w or com pr ised m ult iple in t erconn ect ed ATM b ackb one. New er ks include cov of erag e of imLANs por t ant t opics like VoIacr P oss and an EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Sy st ems, ldwkide leader in net w or king -f Ba or t se he d I n tBack er n et . b on e W he n FiguAut r e h5ored - 3 . by M Cisco ul t i- LAN Ne twworor s Ca n Use an ATM Sw i t ch in g Cel ls I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

LAN Switch

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP LAN sw it ches ar e u sed t o in t er conn ect mu lt iple LAN segm ent s. LAN sw it ch in g p r ovides d ed icat ed, collisionree com unicat ion bet w een net w ork sup porand t f or stmorult iple sim ult aneous Cov ferag e of m cut t ing edge t echn ologies lik edevices, opt ical nwit et h wor k ing age conv er sat ions. LAN swit ches ar e d esigned t o sw it ch dat a fr am es at hig h speeds. Figur e 5- 4 Autes h ored ems, w oraldw idesw leader inernet w nect or king he ps I n tand er n eta. 100 - Mbp s illust rat a simby p leCisco net wSy orkst in w hich LAN it ch int con s a f 1or0-t Mb Et h er n et LAN. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . rLear incorSw por at er net w or kin olog ies in t o1a0LAN/ onm entt. Figu e 5 n- 4how . A t oLAN i t echintCan Lin k g1 t0echn - M bps a nd 0 - MWAN bp senv Et irhe r ne Com plet e w it h new an d u pdat ed chapt er s Segm on secureitnt y , sst or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What lay er of t he OSI r efer ence m odel t o b r id ges and sw it ch es op er at e.

2:

I ndex is cont r olled at t he link lay er? What

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Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : Under By Cisco Systems, Inc. one 4:

popu lar classificat ion schem e w hat are b r id ges classified as?

What is a sw it ch?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Cisco' s w eb sit e (w w w .cisco. com ) is a w ond er f ul sour ce for mor e inf or mat ion ab out t hese t opics. The D ocu m en t at ion sect ion includ es in - dept h discussion s on man y of t he t opics cov ered •in t his chapt er Table . of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

• Clark , Kenn ed y, and Kev in Hamilt on . Cisco LAN Sw it chin g . I nd ianapolis: Cisco Pr ess, Au gust By Cisco Systems, Inc. 19 99. Pub lish er: Cisco Press

• Cisco Syst em s,ber I n 1c.1,Cisco Pub Dat e: Sep tem 2 003 I OS Br idging and I BM Net w ork Solut ions . I nd ianapolis: Cisco Pr ess, Jun e 19 98. 1- 58 705 -1 19 -2 I SBN: Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 6. Routing Basics Obj e ct i ve s • •

Table of Content s

Lear n t he b asics of r out ing pr ot ocols. I ndex

I nt e rn Lear et w ornk ing s Hba et ndbook t heTedchnologie if fer en ces w een, Four lin k-thstEdit at eion an d

dist ance vect or r out in g p rot ocols.

By Cisco Systems, Inc.

Lear n about t he m et r ics used by rou t ing pr ot ocols t o d et er m in e pat h select ion. Pub lish er: Cisco Press

Lear n t he b asics of how dat a t rav els fr om end st at ions t hr ough int er m ed iat e st at ions and on t o t he dest inat ion en d st at ion .

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Under Pages: st 11and 28 t he d if fer en ce bet w een r out ed pr ot ocols an d rou t ing pr ot ocols. This chap t er int r oduces t he und er ly in g con cept s wid ely u sed in r ou t ing pr ot ocols. Top ics sum m arized her e inclu de r out in g p rot ocol com pon en t s and algor it hm s. I n addit ion , t he r ole of r out ing pr ot ocols is br iefly cont r ast ed w it h t h e role of r ou t ed or n et w or k p rot ocols. Sub sequ en t chapt er s in Par t VI I , " Rout ing Pr ot ocols, " addr ess sp ecific r out in g pr ot ocols in m or e det ail, w hile The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t he net w ork pr ot ocols t hat use rou t ing pr ot ocols ar e discu ssed in Par t VI , " Net w or k Pr ot ocols. " essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

What Is Routing? Rou t in g is t he act of m ov ing infor m at ion across an int er net w ork fr om a sou rce t o a d est inat ion . Along t he way , at least one int er m ed iat e nod e t y pically is encoun t er ed. Rout ing is of t en cont r ast ed w it h br idgin g, w hich m ig ht seem t o accom plish p recisely t h e sam e t h ing t o t h e casu al •observ er . The Table ofar Content s en ce b et ween t he t w o is t hat br idging occur s at Lay er 2 ( t he link p rim y dif fer •lay er ) of t he IOSI ndex refer ence m odel, w hereas r out in g occur s at Lay er 3 ( t he net w or k lay er ) . Th is Idist nt e rn et w or kpr ingovid Te chnologie sH ndbook , Four th w Edit inct ion es r ou t in g aand br idging it hion dif ferent inf orm at ion t o use in t he pr ocess of m ovin in for m atInc. ion f r om sour ce t o d est inat ion, so t he t w o f unct ions accom plish t h eir t ask s in By CiscogSystems, dif fer en t w ay s. Pub lish er: Cisco Press

The t opic of r out ing has been cover ed in com put er scien ce lit er at ur e for m ore t han t w o decades, Dat e: Sep tem ber 1 1, 2 003 bu t Pub r out in g achiev ed com mer cial popu larit y as lat e as t he mid - 198 0s. The p rim ar y r eason for I 58 705 -1 19 -2 w or k s in t he 19 70s w er e simp le, h om ogeneous env iron ment s. Only t his t imSBN: e lag1- is t h at net 11 28 t ly has lar ge- scale in t er n et w or k ing becom e p opular . r elat ivPages: ely recen

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Routing Components Rou t ing inv olv es t w o b asic act iv it ies: det er m ining opt im al r ou t ing pat hs and t r anspor t ing inf orm at ion gr oup s ( t y pically called p ack et s) t h rou gh an in t ern et w or k . I n t he cont ex t of t h e r out ing pr ocess, t h e lat t er of t hese is r ef err ed t o as p ack et sw it ching. Alt houg h p ack et sw it ching •is r elat iv ely st Table oft Content r aigh for w ar sd, p at h det er m inat ion can b e v er y com plex . •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Path Determination By Cisco Systems, Inc.

lishpr er:ot Cisco Press RouPub t ing ocols use m et r ics t o ev aluat e w h at pat h w ill b e t he b est for a pack et t o t rav el. A Pub Dat e: Sep tem ber 1, 2m003 m et ric is a st andar d 1of easur em en t , such as pat h ban dw idt h , t hat is used b y r out ing I SBN: 158 705 -1 19 -2 t he opt im al p at h t o a dest in at ion. To aid t he pr ocess of p at h algor it hm s t o det erm ine det er min at ion , r out ing algor it hm s in it ialize an d m aint ain r out ing t ab les, w hich cont ain rou t e Pages: 11 28 inf orm at ion. Rout e in for m at ion var ies dependin g on t h e r out ing algor it hm u sed.

Rou t ing algor it hm s fill r out in g t ables w it h a var iet y of inf orm at ion. Dest in at ion/ nex t h op associat ions t ell a r out er t hat a par t icu lar dest in at ion can be r eached op t im ally b y sen ding t he pack et t o a par t icular r out er r epr esent in g t h e " nex t h op" on t h e w ay t o t he f in al dest inat ion. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of When a r out er receiv es an in com ing p ack et , it check s t he d est inat ion add r ess and at t em pt s t o essent ial an d cu t t ing- edg e t ech nologies. associat e t h is addr ess w it h a nex t hop . Figur e 6- 1 d ep ict s a sam ple dest inat ion/ n ex t hop r out ing t able. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Figu r echapt 6 - 1er . sDe st in at i on/ Nof exim t por Hop at ion s and De tEAP e r mi ne t he D at a' s New include cov erag e t antAssoci t opics like VoI P O pt i m al Pa t h Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov is also extcan end ed n ain ot only t o in new n at et ion, wor ksuch ing concep but talso o oldabilit er , legacy Rou erag t ing et ables also cont ot h er for m as dattas,abou t h e tdesir y of a pat h. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in hich Rou t er s com par e m et rics t o det erm ine opt im al r out es, and t hese m et rics dif fer depend ingwon t he pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease design of t he r out in g alg orit h m used. A var iet y of comm on m et rics w ill be in t rod uced an d pr oduibed ct iv itlat y an e effer iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient descr er dinim t hpr isov chapt . decisions for t h eir net w ork s. Rou t er s com m unicat e w it h one an ot her and m aint ain t heir r out ing t ab les t h r ough t he t r ansm ission of a v ar iet y of m essag es. Th e rou t ing upd at e m essage is one such messag e t hat gener ally con sist s of all or a por t ion of a r out in g t able. By analy zing rou t ing up dat es fr om all ot her r out er s, a r ou t er can bu ild a det ailed pict ur e of n et w or k t op olog y. A link - st at e adv ert isem en t , anot h er ex am ple of a message sen t b et w een r ou t er s, inf or ms ot her r out er s of t he

st at e of t h e send er ' s link s. Link inf or mat ion also can be u sed t o b uild a comp let e pict ur e of net w or k t opolog y t o enab le rou t er s t o det er min e opt im al r out es t o net w or k dest in at ions.

Switching Sw it ching algor it hm s is r elat iv ely sim ple; it is t he sam e f or m ost r out ing pr ot ocols. I n m ost •cases, a hostTable s d et erofmContent in es t hat it m ust send a packet t o anot her host . Hav ing acquir ed a r out er' s •add ress by som I ndex e m eans, t he sou rce h ost sen ds a packet addr essed sp ecifically t o a r out er' s Iph nt ysical e rn et w or k ing TeAccess chnologie s H arndbook , Four th er Edit ( Media Cont ol [ MAC] - lay ) ion addr ess, t h is t im e w it h t h e pr ot ocol ( n et w or k lay er ) add ressSystems, of t he dest By Cisco Inc. in at ion h ost . As it ex am ines t he p ack et 's dest in at ion p rot ocol addr ess, t he r out er det er m in es t hat it eit her Pub lish er: Cisco Press k now s or d oes not k now how t o f orw ar d t he p ack et t o t he next hop. I f t he r out er d oes n ot k now Pub Dat e: Sep tem ber 1 1, 2 003 how t o f or war d t he packet , it t y pically d rop s t he packet . I f t he rou t er kn ow s how t o f orw ar d t he 58 705 -1 19 pack et I,SBN: how1-ever , it ch-2anges t h e dest in at ion p hy sical ad dr ess t o t hat of t he next hop and 11 28 t r ansmPages: it s t he p acket . The n ex t hop m ay be t h e ult im at e dest inat ion host . I f not , t he n ex t hop is usually anot h er rou t er, w hich ex ecu t es t he sam e sw it ch in g d ecision p rocess. As t he p ack et m ov es t hr oug h t h e int er net w ork , it s phy sical addr ess ch anges, bu t it s p rot ocol addr ess rem ains const ant , as illust ed ed in edit Figur e 6The urat pdat ion of2t.he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con Figu ciser ov e er 6 -v 2iew . sNu of m t echn er ou olog s ies Rout essen ert ial sM t oanyet Com wor k ing e ipr ntofession o Pla yalsDu at rall inlev g tels, hef rom nov ice t o ex pert . Sw i t ch in g Pr oce ss New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing The p r ecedingMast discussion betologies, w een a an sour ce and aused destin in at ion end sywstork eming . t echnologies. er t he tdescr er m s,ibes con sw cepittch s, ing t echn d devices t oday ' s net The I n t er nat ion al Or gan izat ion f or St and ar dizat ion ( I SO) has developed a hier archical indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . tCom er min olog is useful in d ed escrchapt ib ingert his t his topt er m in ology k devicesy, plet e wyitthhat new an d u pdat s onp rocess. secur it yUsing , st or age, ical net w ,ornet k inwg,orscalabilit w it hout t h e cap abilit y t o f or w ard pack et s bet w een subn et w or k s ar e called end syst em s ( ESs) and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t ,o all w her eas net w ork d ev ices wit h t h ese capab ilit ies ar e called int erm ediat e syst em s ( I Ss) . I Ss ar e net w or kin g p rof essionals, r egar dless of ex pert ise. fu r t her div ided in t o t h ose t hat can com mu nicat e w it hin rou t ing dom ains ( int r adom ain I Ss) and tReader hose t hs at com unicat e boterh un w itder h instan b et wofeen t ingWAN domnains ( int erd om Ss)ly. A w ill obtmain a g reat andding LANr ou and et w or k ing, p arain t icuI lar t h reout ing dom ain is consider a por ioned of. an int er net unnology der comm adm har dw ar gener e, pr otally ocols, and ser ed v ices invtolv Fu ndam entwalort kech inf oron mat ioninist is prr at ovive ided on aut or it yr ang t hate is latal edsybst y em a psart icular of in adclud mining ist r at ivailed e guiddescr elines. Rous,t ing domquest ains ar e a b rhoad of regu int egr and servset ices, det ipt ion rev iew ions also autcept on omou s rsyst em s. Wit t ain pr ot ocols, r out in gr desou om ain s can b ert div in.t o t o encalled su re con comp eh en sion andh rcer et en t ion, and ad dit ional r ces f or fu herided st udy rCov outerag ing ar butext int r adom rou t ing pr otnocols e st ill used t fs,orbut sw italso chintgo bold ot h h in an d e eas, is also end ed nain ot only t o new et worar k ing concep er wit , legacy bet een systwem s, ar preas. ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Routing Algorithms Rou t in g algorit hm s can be d iff er ent iat ed based on sev eral key char act erist ics. Fir st , t he par t icular goals of t he algor it hm design er aff ect t he op er at ion of t he r esu lt ing rou t ing pr ot ocol. Secon d, v ar ious t y pes of r out ing algor it hm s ex ist , and each algor it hm has a diff er ent imp act on •net w or k and Table of Content s r out er r esou rces. Fin ally , r out in g alg orit h ms use a v ar iet y of met r ics t hat aff ect •calcu lat ion ofI ndex opt im al rou t es. Th e follow ing sect ions analyze t hese rou t ing algor it hm at t r ibu t es. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Design Goals Pub lish er: Cisco Press e: Sepittem 1 1,en 2 003 RouPub t ingDatalgor hmber s oft hav e one or m ore of t he f ollow ing design goals: I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Op t imalit y Sim plicit y an d low over head Rob ust ness and st abilit y The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of enedg ce e t ech nologies. essentRap ial id anconv d cu terg t ingFlex ibilit y Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Op t imnov alit ice y r efer s pert t o t he t o ex . capab ilit y of t h e r out ing algor it hm t o select t he best r out e, wh ich depend s on t he m et r ics an d m et r ic w eig ht ing s used t o m ake t he calcu lat ion . For exam ple, on e New chapt er smay include cov erag e of por ant delays, t opics like P ay andw eig EAP r out ing algor it hm use a n um ber of im hop s tand b utVoI it m h delay mor e h eav ily in t he calculat ion. Nat ur ally , r out in g pr ot ocols m u st defin e t heir m et ric calculat ion alg orit h m s Cov st r ict ly . erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Autalgor h oredit hm by sCisco st desig ems, ned w or ldw ideas leader in as netpossib w or king t he et . t h e r out ing Rou t ing also Sy ar e t o be sim ple le. fIor n ot herI nwt er ornds, algor it hm m u st off er it s fu nct ionalit y eff icient ly , w it h a m inim um of soft war e an d ut iliz at ion Iov n ter ern et w orEfkficiency in g Techis nologies Hand book Ed itt he ionsoft , is w a ar com prplement ehensivein refer t hat head. p art icular ly im por, t Four ant wt hhen e im g t heence r out ing enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing algor it hm m u st r un on a com put er w it h limit ed phy sical r esour ces. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indutst ry .algor Learitnhm how incor at e ,int er netm w ean or kin t echn olog ies ld in tper o afor LAN/ WAN ir onm Rou ing s mt oust b e por r obust w hich sg t hat t hey shou m cor r ectenv ly in t he ent f ace. Com e wor it hunf new an d u pdat edstchapt er ssuon it ydw , stare or age, netload w or kcon in g, of unplet usual oreseen circum ances, ch secur as h ar failuropt es,ical high ditscalabilit ions, andy, and speed, h is book a com plet se e an d tuers p- t oe r efed er ence o or t he op ics ares, essen ial t o all incor rect imtplem en t atis ions. Becau rou ar de at locat at nettw k jtunct iont hat point t h ey tcan net w orconsiderab kin g p rof essionals, r egar pert ise.b est rou t ing algor it hm s ar e oft en t h ose t hat cause le pr oblems whdless en t hof ey ex f ail. The hav e w it hst ood t he t est of t ime and t hat hav e pr ov en st able u nder a var iet y of net w or k Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e condit ions. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a r oad ion, r angrou e oft ing int egr al itsy st em andconv serv in clud.ing descr s, rev iew I nbaddit algor hm s msust erices, ge r apidly Condet verailed gen ce is t ipt he ion pr ocess of agquest r eemions en t , tby o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy all rou t ers, on opt im al r ou t es. Wh en a net w or k ev ent cau ses r out es t o eit her go dow n or. Cov erag is also ext endered n ot ronly new wor concep t ts,hat butper also t o eold erw, ork legacy becom e eavailable, r out s dist ibut et orou t ingn et upd atkeing m essages m eat net s, syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent in w hich st imu lat ing recalcu lat ion of op t imal rou t es and event u ally cau sing all r ou t er s t o agr ees on t hese pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease r out es. Rout in g alg orit h m s t hat conv er ge slow ly can cause r out in g loop s or net w or k out ag es. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions eir net w ork ed s. in Figur e 6- 3 , a packet ar riv es at Rout er 1 at t im e t 1 . Rou t er 1 I n t he r outfor in gt hloop display alr ead y has b een upd at ed an d t hus k now s t hat t he opt im al rou t e t o t he dest inat ion calls f or Rou t er 2 t o be t he nex t st op . Rout er 1 t h er efor e f orw ar ds t he p ack et t o Rout er 2 , bu t b ecause t his r ou t er has not y et been u pdat ed , it b elieves t h at t h e opt im al n ex t hop is Rout er 1 . Rou t er 2 t her efor e for w ar ds t h e pack et back t o Rout er 1 , and t h e packet con t inues t o boun ce back and for t h bet w een t h e t w o r out er s u nt il Rou t er 2 receiv es it s r out ing up dat e or unt il t he pack et has

been sw it ched t he m ax im u m nu mb er of t im es allow ed .

Figu r e 6 - 3 . Sl ow Con ve r gen ce a nd Rou t i ng Loops Can Hi nd er Pr og r ess

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Rou t ing algor it hm s should also be f lex ible, w hich means t hat t hey should qu ick ly and accu rat ely ofy cut ingwedge ologies e opt ical n etex wor ing and age adap tCov t o erag a v areiet of tnet ork cirt echn cu m st an ces.likAssum e, for amkple, t hat sta or net w or k seg m en t h as gon e dow n. As m any r out ing algor it hm s b ecom e aw ar e of t he p r oblem , t hey w ill quickly select Aut-hbored byhCisco st ems, w or leader net went or king f or t erhnms et . can be t he next est pat f or allSyr out es nor mldw allyide using t hatinsegm . Rout in gt he algI norit pr ogr am m ed t o adapt t o ch anges in net w or k band w id t h, rou t er queue size, and net w or k delay , Iam n t ern w her or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat ongetot v ar iables. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Algorithm Com plet e w it hTypes new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net wt ing Rou or kin algor g p rof it hm essionals, s can b er classified egar dless by of tex y pe. pertKey ise. dif ferent iat ors in clu de t hese: Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e v ersus dy nam har dwSt arate,icpr ot ocols, and ic ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Singleh vcomp ersusr mu lt ipat t o en su re conpat cept eh en sionh and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Flat v erovid susinhgieraar syst em s, pr mchical or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Host - int ellig en t v ersus rou t er - int elligent pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t hain eir ver net sus w orkint s.er dom ain I nt r adom Lin k- st at e v er su s dist ance v ect or

Static Versus Dynamic

St at ic r out ing algor it h m s ar e h ard ly algor it hm s at all, but ar e t able m app in gs est ablished b y t he net w or k adm inist r at or befor e t he beginn ing of rou t ing. These map pings do n ot chan ge u nless t h e net w or k adm inist r at or alt ers t hem . Algor it hm s t hat use st at ic r out es ar e sim ple t o d esign and w or k w ell in env iron m en t s w her e net w ork t raf fic is relat ively pr edict able an d w h er e net w or k design is relat iv ely sim ple. Becau se st at ic rou t ing sy st ems can not react t o net w or k chang es, t h ey generally ar e considered Table of Content s un su it able for t oday 's lar ge, const an t ly ch angin g n et w or k s. Most of t h e dom inant r out ing • I ndex algor it hm s t od ay ar e dy nam ic r out ing algor it h m s, w hich adj ust t o chang in g net w ork I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion circum st ances by an alyzing incom ing r out ing up dat e m essag es. I f t he messag e indicat es t hat a By netCisco w or kSystems, chang eInc. has occur r ed , t he r ou t in g sof t w ar e recalcu lat es rou t es and sen ds out new r out ing up dat e m essag es. Th ese m essages p er m eat e t he n et wor k , st im ulat ing r out er s t o r er un t heir hm s Press an d ch ange t h eir rou t ing t ables accor din gly. Pubalgor lish er:itCisco •

Pub Dat e: Sep tem ber 1 1, 2 003

Dy nam ic r out ing algor it hm s can be sup plement ed w it h st at ic rou t es w here appr opr iat e. A r out er I SBN: 1- 58 705 -1 19 -2 of last r esor t ( a r out er t o w hich all unr out ab le pack et s are sent ) , for ex am ple, can be desig nat ed Pages: 11 28 t o act as a reposit or y for all unr ou t able pack et s, en su ring t h at all m essag es are at least han dled in som e w ay .

Single-Path Versus Multipath

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Som e sophist icat ed r out ing p rot ocols sup por t m ult ip le pat hs t o t h e sam e d est inat ion . Unlike single- pat h algor it hm s, t hese m ult ipat h algor it hm s p er m it t raf fic m ult ip lex ing over m ult ip le lines. Con Thecise advov anterages ipatolog h algor it hm st ial ar et oobv pr ov ide suball st an ially f bet v iew sofofmtult echn ies essen n etious: wor kTh ingeyprcan ofession als at levt els, romt er t hr ou nov ghpu t an ice t o dexreliabilit pert . y. This is gener ally called load shar ing. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Flat Versus Hierarchical

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Som eAut r out ing algor it hm sSyop at e in f latide space, w hile ot hwer u se fror outt he in g I hier chies. I n a flat h ored by Cisco ster ems, w ora ldw leader in net orsking n t erar n et . r out ing sy st em , t h e r out er s are peer s of all ot hers. I n a h ier ar ch ical rou t ing sy st em, som e rI nout er et s for wg h at amnologies oun t s t oHand a r out ing ,back e. it Pack bone rouence t er s tt rav t ern w ormk in Tech book Fourbon t h Ed ion ,etiss afr om comnpronback ehensive refer hat el t o tenables he backb one r out er s, w here t hey ar e sent t h rou gh t he b ack bon e unt il t hey r each t he general net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing ar ea of t he d est inaterion . Att ert his , t hey r av elologies, fr om t han e last back bone t hr'oug h won e ing or t echnologies. Mast t he m s,poin contcep t s, ttechn d devices usedrou in tter oday s net ork m or e nonb ack bon e r out er s t o t h e fin al dest inat ion. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Rou ing sy stt ems oft enisdesig nat e logical rou ofenod es, called omain s, aut ous syt st and tspeed, h is book a com plet e an d ugpt o-ps d at r ef er ence t o tdhe t op ics t hatonom are essen ialems, t o all or ar eas. I n hierar chical sy st em s, som e r out er s in a dom ain can com m unicat e w it h rou t ers in net w or kin g p rof essionals, r egar dless of ex pert ise. ot her d omain s, w hile ot her s can com m unicat e only w it h r out er s w it hin t heir dom ain. I n v er y lar ge net w ill or kobt s, ain addit arder chical elsof m LAN ay exand ist , WAN w it h rou t h ep ar high Reader sw a ional g reat hier er un st anlev ding n ettwers or kat ing, t icuest lar hier ly t hare chical level t hocols, e r outand ing back bone. har dwf orm ar e,ing pr ot ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions The r im y adv ant age rof archical out g is tand hat ad it m e or ganizat m ost t o enpsu rearcon cept comp ehhier en sion and rr et enint ion, ditimics ional t rhesou r ces f orion fu rtofher st udy . com panies and t her efor e supp ort s t heir t r aff ic pat t er ns w ell. Most n et w or k com m unicat ion occur s Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy w it hin small com pan y gr oup s ( dom ains) . Because int r adom ain rou t er s n eed t o k now only syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in wabou hich t ot her r out er s w it hin t heir d omain, t heir r out ing algor it hm s can be sim plified, an d, d ep en ding pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease on tpr heodu rou ing b eing sed, rouhelp t inging upd at er eader t r aff icmcan r ede uced accord gly- .eff icient cttiv it y algor an d it imhm pr ov e effuiciency, t he akeb e mor in t elligent , in cost decisions for t h eir net w ork s.

Host-Intelligent Versus Router-Intelligent Som e r out ing algor it hm s assum e t hat t he sou rce end nod e w ill det erm ine t he ent ir e r out e. This is usually r efer red t o as sour ce rou t in g . I n sour ce- r out ing sy st em s, r out er s m er ely act as st or e-

and - for w ar d d ev ices, m ind lessly send in g t he pack et t o t he n ex t st op . Ot h er alg or it h m s assu me t hat host s k now n ot hing abou t r out es. I n t hese algor it hm s, rou t ers det er min e t he p at h t hr ough t h e int ern et wor k b ased on t heir ow n calculat ions. I n t he f ir st syst em , t he host s hav e t h e rou t ing int ellig en ce. I n t he lat t er sy st em , rou t er s h ave t he r out ing int ellig en ce. •

Table of Content s

Intradomain Versus Interdomain • I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Som e r out ing algor it hm s w or k only w it h in d omains; ot her s w ork w it h in an d bet w een dom ains. By Cisco Systems, Inc. The n at ur e of t h ese t w o alg or it h m t y pes is dif fer en t . I t st an ds t o reason, t heref ore, t h at an opt im al in t rad om ain - r out ing algor it hm w ou ld n ot n ecessar ily be an opt im al int er dom ain- r out in g Pub lish er: Cisco Press algor it hm . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 Link-State Versus Distance Vector

Link - st at e algorit hm s ( also kn own as sh ort est p at h fir st algor it hm s) f lood r ou t in g in for m at ion t o all nod es in t h e int er net w ork . Each r out er , how ev er , sends only t he por t ion of t h e r out ing t ab le t hat descr ibes t h e st at e of it s ow n lin ks. I n link - st at e algor it hm s, each r out er b uilds a pict ur e of The u pdat b est ining itr ef erence ides cover ageanof- For d t he en t ire ed n etedit worion k inofit st he r out in g- selling t ab les. allD ist anone ce vnet ectworork algor hm s ( alsop rov k now n as Bellm essent cu tf tor ingedgreout t ech algor it ial hman s) dcall each er nologies. t o sen d all or som e p ort ion of it s r out in g t able, but only t o it s neighb or s. I n essence, link - st at e algor it hm s sen d sm all u pdat es ev er y w here, w hile d ist an ce v ect or alg orit h ms send lar ger up dat es only t o neighb orin g r out er s. Dist an ce v ect or alg orit h ms ov ert heir v iew sneigh of t echn k now Con on lycise about bor s.olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Becau se t hey conv er ge m or e q uick ly , link - st at e algor it hm s ar e somew hat less p ron e t o r ou t ing er s include cov erag e s. of On im por t opics like VoI EAP loops New t h anchapt dist ance vect or algor it hm t h et ant ot her h and, link - stPatand e alg orit h ms requ ir e m or e CPU p ow er an d mem or y t han dist ance v ect or algor it hm s. Link - st at e algor it hm s, t h er efor e, can Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age be m or e ex pensiv e t o im plem ent and supp ort . Link - st at e pr ot ocols ar e gener ally mor e scalable t han dAut ist han ce v by ect Cisco or pr otSy ocols. ored st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net Routing Metrics w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indutst ry .t ables Lear n cont howain t o in incor por at e used int er net oritkin g t echn olog t o a LAN/ WANr env ir onm Rou ing for m at ion by wsw ching soft w ar eies t o inselect t h e best out e. But ent how. , Com plet e w, itarh enew pdat ed chapt erat s on it y , ic st or age, netorm w orat k in g, tscalabilit specif ically r outan ingd tuables b uilt ? Wh is tsecur h e specif nat ur e opt of tical h e inf ion hat t hey y, and ain? speed, t h is is a algor com plet d er u po-ed tat e r one ef er ence heefer t opable ics t hat essen t ial t o all cont How dobook r out ing it hme san d et mtin hat r ou t et ois tpr t o otare hers? net w or kin g p rof essionals, r egar dless of ex pert ise. Rou t ing algor it hm s hav e used man y diff erent m et rics t o det erm ine t he best r out e. Sop hist icat ed Reader w ill obt ain a g reat err out un der st an ding of LAN and m WAN n etcomb w or k ing, t icu lar the r out ing salgor it hm s can base e select ion on mu lt iple et r ics, in ingp ar t hem in ly a single har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on ( hy br id) m et r ic. All t h e follow ing m et r ics hav e been used : a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag Pateh is lenalso gt h ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Reliabilitoper y pr of essionals at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Delay decisions for t h eir net w ork s. Band wid t h Load Com m un icat ion cost

Pat h lengt h is t he m ost com m on r out in g met r ic. Some rou t ing pr ot ocols allow net w or k adm inist r at or s t o assign ar bit r ary cost s t o each net w or k link . I n t his case, p at h leng t h is t he sum of t he cost s associat ed w it h each lin k t r aver sed . Ot h er rou t ing pr ot ocols define h op cou nt , a m et ric t hat specifies t he num ber of passes t hr oug h in t er net w or k in g pr oduct s, such as r out er s, t hat a packet mu st t ak e en r out e fr om a sou r ce t o a dest in at ion . Reliabilit y , in t he con t ex t of rou t ing algor it hm s, r ef er s t o t he dependabilit y ( u su ally descr ibed in •t er ms of t he Table Content bit - erofr or r at e)s of each n et w or k link . Som e net w or k link s m ig ht go d ow n m or e of t en •t han ot h er s. IAf ndex t er a net w or k fails, cert ain net w or k link s m ight be r epair ed m or e easily or m or e Iqu nt ick e rn ly et wt han or k ing otTe h er chnologie link s. sAny H a ndbook reliabilit , Four y fact th Edit or ion s can be t ak en in t o account in t he assig nm en t of t h e rByeliabilit y r at ing s, wh ich ar e ar bit r ar y num er ic valu es u su ally assign ed t o net w ork lin ks b y Cisco Systems, Inc. net w or k adm inist r at or s. er: Cisco Press RouPub t inlish g delay r efer s t o t he lengt h of t im e r equir ed t o m ove a pack et f rom sou rce t o dest inat ion Pub Dat e: Sep tem ber 1w1,or2k. 003Delay depends on m any fact or s, in clu ding t he bandw id t h of t hr ou gh t he int er net I SBN: 158 705 -1 19 -2 int er m ed iat e net w ork lin ks, t h e por t queues at each r out er along t he way , n et w or k cong est ion on all int er m ed11 iat Pages: 28e net w or k lin ks, an d t he ph ysical dist ance t o be t r av eled. Because d elay is a conglom erat ion of sever al im por t ant var iables, it is a comm on and usefu l m et ric.

Band widt h r efer s t o t he av ailable t r aff ic capacit y of a link . All ot h er t hings being eq ual, a 10Mb ps Et h er n et link w ould be p ref er able t o a 6 4- k bps leased line. Alt h ough ban dw idt h is a r at ing of t he max im um at t ain able t hr ou ghpu t on a lin k, rou t es t hr oug h link s w it h gr eat er band w id t h do The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of not necessar ily p rov ide b et t er rou t es t han r out es t hr ou gh slow er link s. For ex am ple, if a f ast er essent ial an d cu t t ing- edg e t ech nologies. link is b usier , t h e act ual t im e r equir ed t o sen d a pack et t o t he dest inat ion could be gr eat er. Load r efer s t o t he d eg ree t o w hich a net w or k resour ce, su ch as a r out er , is busy . Load can be Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom calcu lat ed in a v ar iet y of w ay s, including CPU ut ilizat ion an d p acket s p rocessed per second . nov ice t o ex pert . Mon it or ing t h ese p aram et ers on a cont inual basis can b e r esour ce- in t ensiv e it self . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Com m un icat ion cost is anot her im por t ant m et ric, especially because some com pan ies m ay n ot care about perefor ance m uch as ologies t hey carlik ee about oper atwor ing kexp dit ur es.age Alt houg h line d elay Cov erag of m cut t ingas edge t echn opt ical n et ing en and st or m ay be lon ger, t hey w ill sen d p ack et s ov er t heir ow n lin es r at h er t han t hr oug h t he pu blic lines t hat cost oneybyf or usage t im e. w or ldw ide leader in net w or king f or t he I n t er n et . Aut hm ored Cisco Sy st ems, I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Network Protocols Rou t ed p rot ocols ar e t r anspor t ed by r out in g p rot ocols acr oss an in t er n et w or k . I n g en er al, r out ed pr ot ocols in t his cont ex t also ar e r efer red t o as net w ork p r ot ocols. Th ese net w or k pr ot ocols per for m a var iet y of fu nct ions r equir ed f or com mu nicat ion b et ween user applicat ions in sou r ce •and dest inat ion Table of ices, Content s t hese fu nct ions can diff er w idely amon g p r ot ocol su it es. Net w or k dev and •pr ot ocols occu I ndex r at t he up per f iv e lay er s of t h e OSI r efer en ce mod el: t he n et wor k lay er, t he It rntanspor e rn et w torlay k ing s H alayer ndbook Edit ion erTe , tchnologie he session , t, hFour e prthesent at ion lay er , an d t he app licat ion layer . By Cisco Systems, Inc.

Con fusion about t he t er m s r out ed pr ot ocol an d r out ing pr ot ocol is com m on. Rout ed pr ot ocols are pr ot ocols t hat ar e r out ed over an int er net w ork . Exam p les of such pr ot ocols ar e t he I nt er net Pub lish er: Cisco Press Pr ot ocol ( I P) , DECnet , Ap pleTalk , Nov ell Net W are, OSI , Ban yan VI NES, an d Xer ox Net w or k e: Sep tem ber 1 1, 2 003 Sy stPub emDat ( XNS) . Rout in g p rot ocols, on t he ot her han d, ar e pr ot ocols t hat im plement r out ing I SBN: 58 705 -1 p 19ly-2, r out in g pr ot ocols are u sed by in t er m ediat e syst em s t o build t ables used algor it hm s. 1-Put sim Pages: 11 28 pat h select ion of rou t ed p rot ocols. Ex am ples of t hese pr ot ocols include I n t er ior in det er m ining Gat ew ay Rou t ing Pr ot ocol ( I GRP) , Enhan ced I nt er ior Gat ew ay Rout in g Pr ot ocol ( Enhan ced I GRP) , Open Shor t est Pat h Fir st ( OSPF) , Ex t er ior Gat ew ay Pr ot ocol ( EGP) , Bor der Gat ew ay Pr ot ocol ( BGP) , I n t er m ediat e Sy st em - t o- I nt er m ed iat e Sy st em ( I S- I S) , an d Rout ing I nf orm at ion Pr ot ocol ( RI P) . Rout ed and rou t ing pr ot ocols ar e discu ssed in d et ail lat er in t his book . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

Descr ibe t he pr ocess of r out in g packet s.

2:

I ndex ar e some rou t ing algor it hm t y pes? What

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : Descr By Cisco Systems, Inc.ibe 4:

t he dif fer en ce b et ween st at ic and dy nam ic r out ing .

What ar e some of t he m et r ics u sed by r out in g p r ot ocols?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 7. Network Management Basics Obj e ct i ve • •

Table of Content s

Becom e f am iliar w it h t he basic fun ct ion s of a n et wor k m anag em ent syst em . I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction This chap t er descr ibes fu nct ions com m on t o m ost net w or k - man agem en t ar chit ect u r es an d pr ot ocols. I t also pr esen t s t he fiv e con cept ual ar eas of m anagem en t as defined by t h e I nt er nat ional Or ganizat ion for St andar dizat ion ( I SO) . Su bseq uent ch apt er s in Par t VI I I , •" Net w ork Managem Table of ent Content , " ads dr ess specific n et w or k m anag em ent t echn ologies, p r ot ocols, an d •plat f or ms in m I ndex or e det ail. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

What Is Network Management? Net w ork m an agem ent m eans d iff er ent t hing s t o d iffer ent people. I n som e cases, it in volv es a solit ary n et wor k consult an t m onit or ing net w or k act ivit y wit h an out d at ed p rot ocol analyzer . I n ot her cases, n et wor k m an agement inv olves a dist rib ut ed d at abase, aut op ollin g of n et w or k •dev ices, and Table Content s st at ions g en er at ing r eal- t ime g r aphical v iew s of n et w or k t op ology hig h-ofend w ork •chang es and I tndex r aff ic. I n gener al, net w or k m anagem en t is a ser v ice t h at em ploy s a v ar iet y of It ools, nt e rn etapp w orlicat k ing ions, Te chnologie H aices ndbook Four thhum Edit ion an d dsev t o ,assist an net w or k m anager s in mon it orin g an d m aint aining n etInc. w or k s. By Cisco Systems, Pub lish er: Cisco Press

A Historical Pub Dat e: Sep temPerspective ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

The ear ly 191180s Pages: 28 saw t rem endous ex pan sion in t he ar ea of net w or k deploy m en t . As com panies r ealized t he cost b en ef it s and pr odu ct iv it y g ain s creat ed by net w or k t echnology , t h ey began t o add net w or k s and exp and ex ist ing net w ork s alm ost as r ap id ly as new n et w or k t echnolog ies an d pr odu ct s w er e int rod uced . By t he mid - 198 0s, cer t ain comp anies w er e ex periencing gr ow ing pains fr om d ep loy ing m any d if fer ent ( and som et im es in com pat ib le) net w or k t ech nologies. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of The p r oblem s associat ed w it h net w ork ex pan sion aff ect bot h day - t o- d ay net w or k oper at ion essent ial an d cu t t ing- edg e t ech nologies. m anagem ent and st r at egic n et wor k g row t h p lan ning. Each new net w or k t ech nology r equir es it s ow n set of ex per t s. I n t he early 1 980 s, t he st af fing r equir em ent s alon e for man aging lar ge, het er ogeneous or ks sofcrteat edolog a crisis f or mt ial anyt oornganizat u rg enals t n eed oseels, f or f rom Con cise ovnet er vwiew echn ies essen et wor k ion ing s.prAn ofession at allarlev aut omnov at ed net w or k m anagem en t ( in clud ing w hat is t yp ically called net w or k capacit y plann in g) ice t o ex pert . int egr at ed acr oss div erse env iron m en t s. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Network Management Architecture Most net w ork m an agement ar ch it ect u res u se t he sam e basic st ru ct ur e and set of r elat ionship s. En d st at ion s ( m anaged devices) , su ch as com pu t er sy st ems and ot her net w or k dev ices, r un soft w ar e t h at enables t h em t o send aler t s w h en t hey r ecog nize pr ob lem s ( f or exam ple, w hen one •or m or e user-Table ofm Content det er ined tshr eshold s ar e ex ceeded) . Up on receiv ing t hese aler t s, m anag em ent •ent it ies ar e pr I ndex ogr am med t o react b y ex ecut ing one, sever al, or a gr oup of act ion s, inclu ding Ioper nt e rnat etor w or k ing Te chnologie s H aloggin ndbookg, , Four them Editshu ion t dow n, and aut om at ic at t em pt s at sy st em r epair . not if icat ion , event sy st By Cisco Systems, Inc.

Man agement ent it ies also can p oll en d st at ion s t o ch eck t h e valu es of cer t ain v ar iables. Polling can be aut om at ic or user - init iat ed, but agent s in t h e man aged devices respon d t o all polls. Pub lish er: Cisco Press Agent s are sof t w are mod ules t hat fir st com pile inf orm at ion abou t t h e m anaged devices in w h ich Dat e: Sep tem ber 1 1, 2 003 t heyPub r esid e, t hen st or e t h is infor m at ion in a m anagem en t d at abase, and fin ally p rov ide it I 58 705 -1 19 -2 ( pr oact SBN: iv ely1-or r eact ively) t o man agem en t ent it ies w it hin net w ork man agem en t sy st em s ( NMSs) v ia a nPages: et wor11k 28 m an agement pr ot ocol. Well- kn own n et w or k m anag em ent pr ot ocols in clu de t h e Sim ple Net w ork Managem en t Pr ot ocol ( SNMP) and Com m on Manag em ent I n for m at ion Prot ocol ( CMI P) . Manag em ent pr oxies ar e ent it ies t hat pr ov id e m anagem ent in for m at ion on b eh alf of ot her ent it ies. Figur e 7- 1 d ep ict s a t y pical net w or k m anag em ent archit ect ur e. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r e 7 - 1 . A Ty pi cal N et w or k M an age m e nt Ar chi t e ct u r e M ai nt ai ns M a ny Rel at ionshi ps Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ISO Network Management Model The I SO has cont rib ut ed a gr eat d eal t o n et w or k st and ard izat ion. I t s n et w or k m anag em ent m odel is t h e pr imar y m eans f or un der st an ding t he maj or f unct ions of n et w or k m anag em ent syst em s. This m odel consist s of fiv e concep t ual ar eas, as discussed in t he n ex t sect ions. •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Performance Management By Cisco Systems, Inc.

The g oal of per for m ance m anagem en t is t o m easu re and mak e av ailable v ariou s aspect s of Pub net w orlish k er: perCisco for mPress ance so t h at int er net w or k per for m ance can b e m ain t ained at an accept ab le Pub Dat e: Sep temof berper 1 1,for 2 003 level. Ex am ples m ance var iables t h at m ight be pr ovided include n et wor k t h r ough put , I SBN: 158 705 -1 19 -2 user r espon se t imes, and line u t ilizat ion . Pages: 11 28

Perf or man ce man agem en t inv olv es t hr ee m ain st ep s. Fir st , per for m ance dat a is gat hered on v ariab les of int er est t o net w ork adm in ist r at or s. Secon d, t he dat a is analy zed t o det erm ine nor m al ( b aseline) levels. Fin ally , ap pr opr iat e per for m ance t hr esholds ar e d et er m in ed f or each im por t ant var iable so t hat ex ceedin g t h ese t h r esholds in dicat es a net w or k pr oblem w or t hy of at t ent ion . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d ent cu t it t ingt ech nologies. Man agement ies edg con teinually m onit or perf or man ce var iables. When a per for m ance t hr eshold is exceed ed , an aler t is gener at ed and sent t o t h e net w or k m anagem en t sy st em . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Each of t he st eps j ust descr ibed is p ar t of t h e pr ocess t o set up a r eact iv e sy st em . Wh en nov ice t o ex pert . per for m ance becom es u naccept able because of an ex ceeded user- d ef ined t hr eshold , t he sy st em r eact s b y sen ding a m essag e. Per f orm ance m anag em ent also per mit s pr oact iv e m et hods: For New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP exam ple, n et w or k sim ulat ion can be u sed t o pr oject how net w or k gr ow t h w ill affect p er f orm an ce m et rics. t adologies m in ist r at t oical impnen pr oblem s or soage t h at coun t er act ive CovSuch erag esim of ulat cut tion ing can edgealer t echn likor e sopt et ding wor k ing and st m easu res can be t ak en. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . IConfiguration n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Management enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing The conf igur att oion m an agem t owmoronit n et wor k an conWAN figu rat ion indu gstoal ry . of Lear n how incor por at e ent int erisnet kin or g t echn olog iesdinsyt ostaem LAN/ env ir onm ent . inf orm at ion so t h at t h e ef fect s on net w or k oper at ion of v ar ious v ersions of h ard w are and Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, soft ar e elem ent s canis be t rack ed ean . e r ef er ence t o t he t op ics t hat are essen t ial t o all and wspeed, t h is book a com plet anddmuanag p- t o-ed d at net w or kin g p rof essionals, r egar dless of ex pert ise. Each net w or k device has a v ar iet y of v ersion infor m at ion associat ed w it h it . An engin eer in g w or kst at for ain ex am edofasLAN follow Reader s ion, w ill obt a gple, reatm eray unbe derconf st anigur ding ands: WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e ofsyst intem egr,alVersion sy st em3. s2 and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Op er at ing t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag also end ed ot only Et heeris n et int ext er face, Vernsion 5 . 4t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e, e. Ver Tools and TCP/ I P sof t w ar sion 2 .0gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions Net War for et hsof eirt w net arw e,ork Ver s.sion 4 . 1 NFS soft w ar e, Version 5. 1 Serial com m un icat ions con t roller , Version 1. 1 X. 25 soft w ar e, Ver sion 1. 0

SNMP sof t w ar e, Ver sion 3 .1 Con figu rat ion m anag em ent su bsyst em s st ore t his inf or mat ion in a d at abase for easy access. When a p rob lem occur s, t h is dat abase can be searched for clu es t hat m ay h elp solve t he pr oblem . •

Table of Content s

Accounting Management • I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

The g oal of accou nt ing m an agem ent is t o m easu re net w ork u t ilizat ion p aram et ers so t hat By Cisco Systems, Inc. indiv idual or gr oup u ses on t he net w ork can be r egu lat ed app rop riat ely . Such regu lat ion m inim izes n et w or k p rob lem s ( b ecause n et w or k r esou rces can b e app ort ion ed based on r esour ce Pub lish er: Cisco Press capacit ies) and max im izes t he f air n ess of net w or k access acr oss all user s. Pub Dat e: Sep tem ber 1 1, 2 003

As w it hI SBN: per for 1- 58 m705 ance -1 19m -2 anagem en t , t h e fir st st ep t owar d app rop riat e accoun t ing m anagem en t is t o measur e ut ilizat ion of all im por t ant net w ork resour ces. An aly sis of t he r esult s pr ov ides insight Pages: 11 28 int o cu r rent usage p at t ern s, and usage q uot as can be set at t his p oint . Som e cor rect ion, of cour se, w ill b e r eq uir ed t o reach opt im al access pr act ices. Fr om t his p oint , on going m easu rem en t of r esou r ce u se can y ield billing infor m at ion as w ell as inf orm at ion used t o assess cont inu ed f air and opt im al r esou rce u t ilizat ion . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Fault Management

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The g oal of fau lt m anagem en t is t o det ect , log, n ot ify u ser s of , and ( t o t he ex t en t p ossible) nov ice t o ex pert . aut om at ically fix n et w or k pr ob lem s t o keep t he net w or k r unn ing ef fect ively . Becau se f ault s can cause dow nt im e or unaccep t able net w or k degr adat ion , fau lt m anag em ent is per haps t he m ost New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP w idely imp lem ent ed of t he I SO net w ork man agement elem ent s. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Fault m an agement inv olves f irst det er m ining sym p t om s and isolat in g t h e pr oblem . Then t he pr oblem f ixedbyand t heSy solut ion is t est edide onleader all- impinornet t ant suking bsystf or emt s. Aut hisored Cisco st ems, w or ldw w or he Finally I n t er n,ett h. e det ect ion and r esolut ion of t h e pr oblem is r ecor ded. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Security Management indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, The g oal of secur it y m anagem en t is t o cont r ol access t o net w or k r esour ces accor ding t o local and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all gu id elines so t hat t he n et w or k cannot be sab ot aged ( in t ent ionally or u nint ent ionally ) an d net w or kin g p rof essionals, r egar dless of ex pert ise. sen sit iv e inf orm at ion cannot be accessed by t hose w it hou t ap pr opr iat e aut h or izat ion . A secur it y m anagem su ain bsyst , for onLAN it or user log ging a net resour Reader s went ill obt a em g reat er ex unam derple, st ancan dingmof and sWAN n et won or kt oing, p arwt ork icu lar ly t h ece and can refu se access t o t h ose wh o ent er inap pr opr iat e access codes. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Secu rit y man agement subsy st em s w or k by par t it ioning net w or k r esour ces int o au t hor ized an d t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . un aut hor ized areas. For some user s, access t o any net w or k r esou rce is inap pr opr iat e, m ost ly Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy because such u ser s ar e usually com pany out siders. For ot h er ( int ern al) net w or k user s, access t o syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich inf orm at ion or iginat ing f rom a par t icular d ep art m ent is inapp rop r iat e. Access t o Hum an pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Resour ce files, f or ex amp le, is in appr opr iat e f or m ost user s out side t h e Hum an Resou rces pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient depar t m ent . decisions for t h eir net w ork s. Secu rit y man agement subsy st em s p er f orm sev er al f un ct ion s. They ident ify sensit ive net w ork r esour ces ( including sy st em s, files, and ot her ent it ies) and d et er m in e m appin gs bet w een sen sit iv e net w or k r esour ces and user set s. Th ey also mon it or access point s t o sensit ive n et wor k r esour ces and log in appr opr iat e access t o sen sit iv e net w or k r esour ces.

Review Questions 1:

Nam e t he d iff er ent areas of n et w or k m anag em ent .

2:

I ndex ar e t he goals of per for m ance m anagem en t ? What

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : What By Cisco Systems, Inc.ar e 4:

t he goals of config ur at ion m an agement ?

What ar e t he goals of accou nt ing m anagem ent ?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

What ar e t he goals of fau lt m anag em ent ?

I SBN: 1- 58 705 -1 19 -2 Pages: 28 6 : 11What

ar e t he goals of secur it y m anag em ent ?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Part II: LAN Protocols Ch apt er 8 Et her net Technologies • •

Ch apt er 9 Fiber Dist r ibut ed Dat a I nt erf ace Table of Content s I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 8. Ethernet Technologies Obj e ct i ve s • •

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Under st and t he r equir ed an d opt ional MAC f r ame for m at s, t heir pu rp oses, and t h eir I ndex com pat ibilit y r eq uir em ent s.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco List Systems, t he v arInc. iou s

Et h er net phy sical lay er s, sign alin g pr ocedu res, and link m edia r eq uir em ent s/ lim it at ion s.

Pub lish er: Cisco Press

Descr ibe t he t r ade- off s associat ed w it h im plem en t ing or up gr ading Et h er n et LANs—choosing dat a rat es, op er at ional mod es, an d net w ork equ ipm en t .

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background The t er m Et h er n et r efer s t o t he f am ily of local- ar ea net w ork ( LAN) pr oduct s cov er ed by t h e I EEE 80 2. 3 st an dar d t hat defines w hat is com mon ly kn ow n as t he CSMA/ CD pr ot ocol. Thr ee dat a r at es ar e cu rr ent ly d ef ined f or op er at ion over op t ical fiber an d t w ist ed- pair cab les: •

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ps— hern et, Four th Edit ion I nt e rn 10 et w Mb or k ing Te 10Basechnologie T s HEt a ndbook By Cisco Systems, Inc.

10 0 Mbps— Fast Et her net

Pub10 lish00 er: Mbp Ciscos— Press Gigabit

Et h er net

Pub Dat e: Sep tem ber 1 1, 2 003

10 - Gigabit h er net is-2und er developm ent and w ill lik ely be pu blish ed as t he I EEE 8 02. 3ae I SBN: Et 1- 58 705 -1 19 supp lem ent t o t h e I EEE 80 2. 3 base st andar d in lat e 200 1 or ear ly 20 02. Pages: 11 28 Ot h er t echn ologies and pr ot ocols hav e been t ou t ed as lik ely replacement s, but t he m ar k et has spok en . Et h er n et has sur v ived as t he maj or LAN t ech nology ( it is cur rent ly used f or app rox im at ely 85 percent of t he w or ld' s LAN- connect ed PCs and w or kst at ion s) because it s pr ot ocol h as t he f ollowin g char act erist ics: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. I s easy t o un der st an d, im plem en t , m anage, an d m aint ain Allow Con cise s lowov ercost v iewnet s of w ork t echn imolog plemies en essen t at ions t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Pr ovid es ex t ensive t op ological flex ib ilit y f or n et w or k inst allat ion New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Gu aran t ees successfu l int er con nect ion an d op er at ion of st andar ds- com pliant pr oduct s, rCov eg ar erag dless e ofofcut m anu t ingfact edge ur er t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Ethernet—A Brief History The or igin al Et h er net w as developed as an ex per im en t al coaxial cab le net w ork in t h e 197 0s b y Xerox Cor por at ion t o oper at e w it h a d at a r at e of 3 Mbp s using a car r ier sense m ult iple access collision det ect ( CSMA/ CD) p rot ocol for LANs w it h spor ad ic but occasionally heav y t r aff ic •r eq uir em ent s. Table of Content Su ccess wit hs t h at p roj ect at t r act ed ear ly at t ent ion and led t o t he 1 980 join t •dev elop ment I ndex of t he 1 0- Mb ps Et hern et Version 1. 0 sp ecificat ion by t h e t hr ee- com pan y Iconsor nt e rn ettw Teitchnologie s H aen ndbook , Four Edit iuormk:ing Dig al Equ ipm t Corp oratthion , Iion nt el Corp orat ion , and Xerox Cor por at ion. By Cisco Systems, Inc.

The or igin al I EEE 80 2. 3 st an dar d w as based on , and w as v er y sim ilar t o, t he Et her net Ver sion 1. 0 specif icat ion . The d raf t st an dar d w as appr ov ed by t he 8 02. 3 w ork ing gr oup in 19 83 and w as Pub lish er: Cisco Press subsequent ly published as an off icial st an dar d in 19 85 ( ANSI / I EEE St d. 8 02. 3 - 198 5) . Since t h en , Pub Dat e: Sep tem ber 1 1, 2 003 a n um ber of supp lem ent s t o t he st an dar d hav e been d ef ined t o t ak e adv ant ag e of im pr ovem en t s SBN: 1- 58 705 19 -2 in t he tI echnolog ies-1 an d t o supp ort add it ion al net w or k m edia and h ig her dat a r at e capabilit ies, Pages: 28 opt ional net w or k access con t r ol feat u res. plus sev er al11new Thr oug hout t he rest of t h is ch apt er , t he t er m s Et h er n et an d 80 2. 3 w ill r efer ex clusiv ely t o net w or k im plem ent at ion s comp at ible w it h t he I EEE 8 02. 3 st andar d. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Ethernet Network Elements Et h er n et LANs consist of net w or k nod es and int erconn ect ing m edia. The net w ork nodes f all int o t w o m aj or classes: •

Table of Content s

D a t a t er m ina l e qui pm en t ( D TE) — Devices t hat are eit h er t he sour ce or t he dest in at ion I ndex fr Te amchnologie es. DTEs e t y pically devices I nt e rn of et wdat or ka ing s Har a ndbook , Four th Edit ion such as PCs, w or kst at ions, f ile ser v er s, or p rint ser v ers t hat , as a gr oup , ar e all of t en r efer red t o as en d st at ions. By Cisco Systems, Inc. •

D a t a com m uni cat i on equ ipm e nt ( D CE) — I n t er m ediat e net w or k dev ices t h at r eceiv e and acr oss t he net w ork . D CEs m ay b e eit h er st andalone d ev ices su ch as Pub Dateat e: Sep tem berw1or 1, k 2 003 r ep er s, net sw it ch es, an d r out er s, or com m unicat ions int er face u nit s such as int I SBN: er face 1- 58car 705 ds -1 19and -2 m odem s.

Pubfor lishwer: Press arCisco d fr am es

Pages: 11 28

Thr oug hout t his chap t er, st an dalone in t er m ediat e net w or k dev ices w ill be r efer r ed t o as eit her int erm ediat e nod es or DCEs. Net w or k int er face card s w ill be r efer red t o as NI Cs. The cu rr ent Et her net m edia opt ions in clud e t w o g en er al t yp es of copp er cab le: unshielded t w ist ed - pair ( UTP) an d sh ielded t w ist ed- p air ( STP) , p lu s sev eral t y pes of opt ical f ib er cab le. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Ethernet Network Topologies and Structures LANs t ake on m any t opological config ur at ions, bu t r egar dless of t heir size or com p lex it y, all w ill be a comb inat ion of only t hr ee basic int er connect ion st r uct ur es or n et w or k b uilding blocks. •The sim plest Table ofur Content s point - t o- point in t erconn ect ion, sh ow n in Figur e 8- 1 . Only t w o st r uct e is t he •net w or k un it s I ndex are in volv ed, an d t he connect ion may b e DTE- t o- DTE, DTE- t o- D CE, or DCE- t oIDCE. nt e rn et w orcab k ingleTein chnologie a ndbook th Edit ion The p oin t - tso-H poin t int, Four er connect ions is k now n as a net w ork lin k. Th e m axim um allow able len gt h of t he lin k depends on t h e t y pe of cable an d t h e t r ansm ission met hod t h at is By Cisco Systems, Inc. used. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Figu r e 8 - 1 . Exa m ple Poin t - t o- Poin t I n t er conn ect ion

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. er net v iewnet s of t echn t ial k ing prbofession at as all show lev els, f rom The orCon igincise al Etov h er w ork s wolog er e ies impessen lem ent edt ownitet h wor a coaxial us st r uctals ur e, n in nov ice t o ex pert . Figur e 8- 2 . Segm ent leng t hs w er e limit ed t o 5 00 m et er s, and up t o 100 st at ions cou ld b e connect ed t o a sing le segm ent . I n divid ual segm en t s could be int er connect ed w it h r ep eat er s, as New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP long as m ult iple p at hs d id n ot ex ist bet w een any t wo st at ions on t he net w ork and t he n um ber of DTEs did not ex ceed 10 24. Th e t ot al p at h dist ance bet w een t h e most - d ist an t p air of st at ion s w as Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age also not allow ed t o ex ceed a m ax imu m pr escr ibed value. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat r e 8 - 2t.o Exa m ple l Bus Topol ogy enables net w or kin g pFigu r ofessionals un derst and Coax an d imia plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Alt hou gh new net w or ks are no lon ger connect ed in a b us conf ig ur at ion, som e older b us-

connect ed n et w or k s do st ill ex ist and ar e st ill usefu l. Since t he ear ly 19 90s, t h e net w or k config ur at ion of choice has been t h e st ar- conn ect ed t opology , show n in Figur e 8- 3 . Th e cent ral net w ork unit is eit h er a m ult ipor t repeat er ( also k now n as a hu b) or a n et w or k sw it ch . All conn ect ions in a st ar net w ork are p oint - t o- p oin t link s im plem en t ed w it h eit h er t w ist ed- p air or opt ical f iber cable. •

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Figu r e 8 - 3 . Exa m ple St a r -Conn ect e d Topolog y

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

The IEEE 802.3 Logical Relationship to the ISO Reference Model Figur e 8- 4 sh ows t he I EEE 8 02. 3 logical lay er s and t h eir r elat ionship t o t h e OSI r efer en ce mod el. •As w it h all I EEE Table80 of2Content s pr ot ocols, t h e I SO d at a link lay er is div ided in t o t w o I EEE 80 2 sub layer s, •t he Med ia Access I ndex Con t r ol ( MAC) sublay er and t he MAC- client sublay er. The I EEE 8 02. 3 ph ysical Ilay nt eer rn et w or k ing Teds chnologie H a ndbook , Four th Edit cor r espon t o t he sI SO ph ysical layer . ion By Cisco Systems, Inc.

Pub lish er: Cisco Press

Figu r e 8 - 4 . Et he r ne t ' s Logi cal Rel at ion sh ip t o t he I SO Re fe r e nce M od el Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu MACst ry . Lear how t oerincor e int er tnet or kining g t echn olog ies in t o a LAN/ WAN env ir onm ent . The clientn sublay m aypor beaton e of he wf ollow : Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Log Cont r ol (rLLC) if t h eofunex it pert is a ise. D TE. Th is su blay er p r ovides t h e int er face bet w een net w or kinical g p Link rof essionals, egar,dless t he Et her net MAC an d t he up per layer s in t he p rot ocol st ack of t h e end st at ion . The LLC Reader s w illerobt a g reat un der st .2 an st ding sublay isain defined byerI EEE 802 andof ardLAN s. and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Br idge it yint , ifegr t hal e unit is as Dand CE. serv Br idg e ent ies ing pr ovid LAN-descr t o- LAN ints, er rev faces w een a b r oad r angent e of sy st em ices, in it clud det e ailed ipt ion iewbet quest ions LANs t hat u secomp t he sam e sion pr ot ocol orenexam hern et t o rEt her rnet een t o en su re con cept r eh en and (rfet t ion,ple, andEt ad dit ional esou ces) fand or fualso rt herbet stw udy . dif fer enalso t pr ot ocols ( f orn ot exam Et hern etwor t o kToken Ring )t.s,Brbut id ge enttitoies ed by Cov erag e is ext end ed onlyple, t o new n et ing concep also oldar ere, defin legacy I EEE 02. 1instg andar syst em s, pr8ovid a m ords. e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Becau seivsp ions LLC and brhelp idgeing entt he it ies ar e com monmor f oreall EEE 8 02 LAN- eff p r ot ocols, pr odu ct it yecificat an d im pr ovf or e eff iciency, r eader m ake in tIelligent , cost icient net w or k comp ibilit y wbecomes t h e pr im ary r esponsibilit y of t he par t icu lar net w ork pr ot ocol. decisions for t hateir net ork s. Figur e 8- 5 sh ows diff er ent com p at ibilit y requ irem ent s im posed b y t he MAC an d p hy sical lev els for basic dat a com m un icat ion ov er an Et her net link .

Figu r e 8 - 5 . M AC a nd Phy si ca l Lay er Com pa t i bil it y Re qui r em e nt s f or Ba si c D at a Com m u ni cat ion

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Newlay chapt er s rinclude eragaccess e of imtpor t opics VoI and P and The MAC er cont ols t he cov n ode's o t ht ant e net w ork like media is EAP specif ic t o t h e indiv idual pr ot ocol. All I EEE 8 02. 3 MACs mu st m eet t he sam e basic set of logical r equir em ent s, r egar dless Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age of w het her t h ey in clu de one or m ore of t he defin ed opt ion al pr ot ocol ex t en sion s. The only r eq uir em ent for b asic com m un icat ion ( comm u nicat ion t h at d oes n ot r equir e op t ion al pr ot ocol Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . ext ensions) bet w een t w o n et w or k n odes is t hat bot h MACs mu st supp or t t h e sam e t ran sm ission rI natt ern e. et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing The 8 02. 3 ph ysical layer is specific t o t he t ran sm ission dat a r at e, t he sign al encoding, and t he t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t y pe of m edia in t er connect ing t he t w o nod es. Gig abit Et her net , f or ex am ple, is def in ed t o indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . oper at e ov er eit h er t w ist ed- p air or opt ical f iber cable, but each specif ic t y pe of cable or sign alCom plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, encoding pr oced ur e r eq uir es a dif fer en t p hy sical lay er im p lem ent at ion. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

The Ethernet MAC Sublayer The MAC sub layer h as t w o p rim ar y r espon sib ilit ies:

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Dat a encapsulat Table of Content ion, includ s ing fr am e assem bly bef ore t ran sm ission , and f ram e par sing/I ndex er r or det ect ion du rin g an d aft er r ecept ion

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Media access con t rol, in clu ding init iat ion of fr am e t r ansm ission an d recover y fr om t r ansm ission failur e

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 The Basic Ethernet Frame Format I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The I EEE 802 .3 st and ard d ef ines a b asic d at a f r ame f or m at t h at is r equir ed f or all MAC im plem ent at ion s, plus sever al ad dit ional op t ional f orm at s t hat are used t o ex t end t he pr ot ocol' s basic capabilit y . The basic dat a fr am e for m at cont ain s t he sev en f ields show n in Figur e 8- 6 . re am e (ion P RE) s of 7 by Th e net PRE is an ererence nat in g ppat n ofcover on esage andofzer os The uP pdat ed bl edit of — t heConsist b est - selling all-t es. in- one w ork ingalt r ef rovt er ides t ells receiv ionsnologies. t h at a fr am e is com in g, an d t hat pr ovides a m ean s t o essentt hat ial an d cu t t ing-ing edgsteatt ech syn ch r onize t he f r am e- r ecept ion p ort ion s of receiv ing ph ysical layer s w it h t he in com ing bit st r eam . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov t o fr exam pert St a ice rt - ofe .de li m it e r ( SOF) — Consist s of 1 by t e. The SOF is an alt er nat ing pat t er n of ones an d zer os, en ding w it h t w o consecu t ive 1 - bit s in dicat in g t hat t he nex t b it is t h e lef t New s include covberag imdpor ant ion t opics VoI P and EAP m ost chapt bit inert he left - m ost yt e eofoft he esttinat addlike ress. Cov of cut t ingess edge t echn ologiesslik et ewor st or agew h ich st at ion( s) D e sterag i na et ion a ddr ( D A) — Consist ofe6opt byical t es. nTh DAk ing fieldand ident if ies should r eceive t he f ram e. The lef t - m ost bit in t h e DA field ind icat es w het h er t he add r ess is Aut h oredidual by Cisco Sy st( indicat ems, wed or ldw ide netadd w orress king (find or icat t he ed I n tby er naet1) . . Th e second an indiv addr ess by a 0 )leader or a grinoup bit fr om t h e lef t in dicat es wh et her t he D A is glob ally ad m in ist er ed ( in dicat ed by a 0) or I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat locally ad m in ist er ed ( in dicat ed by a 1) . The r emain in g 4 6 bit s ar e a u niqu ely assigned enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing v alue t hat ident if ies a sin gle st at ion, a defin ed gr oup of st at ions, or all st at ions on t he t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing net w or k. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet w it hadnew er ss of on 6secur it y ,ThsteorSA age, optident ical net w or g, ding scalabilit y, Soue rce dre an ssed su (pdat SA )ed — chapt Consist by t es. f ield ifies t h ke insen st at ion. and speed, t h is book is a com plet e an d u pt od at e r ef er ence t o t he t op ics t hat are essen t ial The SA is alw ays an ind ividu al add r ess and t h e lef t - m ost bit in t he SA field is alw ay s 0. t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Le ng t h/ Typ e— Consist s of 4 by t es. Th is field in dicat es eit her t h e nu mb er of MAC- client Reader s aw ill g reat er ained un der st LAN of and WAN et worortkhing, p aret icu larIlyD tifh et he dat by obt t es ain t hata ar e cont inan t hding e datof a field t he f ramn e, e fr am t y pe har dwfrar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is less pr ov tided am e is assem bled using an opt ional for m at . I f t he Len gt h/ Ty pe field v alue is han on or a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions equal t o 1 500 , t he n um ber of LLC by t es in t h e Dat a field is equ al t o t he Leng t h/ Ty pe f ield t o en su re con compt h/ r eh and r et en ion, ad dit1ional ces fis oran fu rt st udy . v alue. I f cept t he Leng Tyen pesion f ield v alue is t gr eatand er t han 536, rt esou he f r rame opher t ional t y pe Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy fr am e, and t h e Lengt h/ Ty pe f ield valu e ident ifies t he par t icu lar t y pe of f ram e b eing sent or syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich r eceived. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr oduDctaivt a— it y an pruence ov e effoficiency, ingy tvhe eader m ake t elligent cost I s da im seq n b yt eshelp of an alur e, w here n ismor lesse tin han or equ, al t o- eff 150icient 0. I f t he decisions for t h eir net w ork s. lengt h of t he Dat a f ield is less t han 46, t he D at a f ield m ust b e ex t end ed by adding a filler ( a pad ) suf ficien t t o br ing t he D at a f ield len gt h t o 46 by t es. Fra m e ch eck se que nce ( FCS) — Consist s of 4 by t es. Th is sequ en ce con t ains a 32- b it cyclic r ed und ancy check ( CRC) v alue, w hich is cr eat ed by t he sending MAC and is r ecalculat ed b y t he receiv ing MAC t o check for dam aged fr am es. Th e FCS is g en er at ed over

t he DA, SA, Len gt h/ Ty pe, an d Dat a f ield s.

Figu r e 8 - 6 . The Ba si c I EEE 8 0 2 .3 M AC Da t a Fr am e For m at

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

NO TE

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

I ndiv idual addr esses ar e also k now n as un icast ad dr esses because t hey r efer t o a Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . single MAC and ar e assig ned by t he NI C m anu fact ur er fr om a block of addr esses allocat ed by t he I EEE. Gr oup ad dr esses ( a.k . a. m ult icast ad dr esses) ident ify t he end I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat st at ions in a w or k gr oup and ar e assig ned b y t he n et wor k m an ager. A special gr oup enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing add ress ( all 1 s—t he br oadcast ad dr ess) in dicat es all st at ions on t he n et wor k . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kinTransmission g p rof essionals, r egar dless of ex pert ise. Frame Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Whenev er an en d st at ion MAC r eceives a t ran sm it - f r ame requ est wit h t h e accom pan yin g ad dr ess har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on and dat a inf orm at ion fr om t he LLC su blayer , t h e MAC begins t he t r ansm ission sequ en ce by a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t r ansfer r in g t he LLC in for m at ion in t o t h e MAC fr am e bu ff er . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr g a pict ur e ofit er t hearrealw ort ed ld ninet twhe or PRE k ing and en virSOF onmf ent s in w hich The p r ovid eam in ble anmd or stearrtealist - of - fric am e delim e inser ields. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr oduThe ct iv it an d im ov de sour eff iciency, ingart he ake moraddr e iness t elligent , cost - eff icient d yest inat ionpran ce add help resses e inr eader ser t ed m int o t he field s. decisions for t h eir net w ork s. The LLC dat a by t es ar e count ed, and t he n um ber of by t es is insert ed int o t he Len gt h/ Ty pe field. The LLC dat a by t es ar e inser t ed int o t he Dat a field. I f t h e num ber of LLC dat a by t es is less t han 4 6, a pad is added t o br in g t he Dat a field leng t h up t o 4 6.

An FCS v alue is g en er at ed over t h e DA, SA, Len gt h / Typ e, and Dat a field s and is app en ded t o t he end of t he Dat a f ield . Aft er t he f ram e is assem b led, act ual f ram e t r an sm ission w ill depend on w het her t he MAC is oper at ing in h alf- d uplex or f ull- dup lex m ode. The I EEE 802 .3 st and ard cur r ent ly r eq uir es t hat all Et her net MACs sup por t h alf - du plex oper at ion, in w hich t he MAC can be eit her t r ansm it t ing or r eceiving a fr am e, but it cann ot b e • Table of Content s doing b ot h sim ult aneously . Full- dup lex op er at ion is an opt ional MAC cap abilit y t hat allow s t he • I ndex MAC t o t ran sm it and r eceiv e f r ames sim ult aneously. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Half-Duplex Transmission—The CSMA/CD Access Method Pub lish er: Cisco Press Dat e: CD Sep tem ber 1 1, 2w003 ThePub CSMA/ pr ot ocol as or iginally d ev elop ed as a m ean s by w h ich t w o or mor e st at ions cou ld I SBN: 158 705 -1 19 -2 in a swit ch- less env ir on ment w hen t he p rot ocol d oes not requ ir e cent r al shar e a com m on media ar bit r at ion, 11 access t okens, or assigned t im e slot s t o ind icat e wh en a st at ion w ill b e allow ed t o Pages: 28 t r ansm it . Each Et h er net MAC det er m ines for it self w hen it w ill be allow ed t o sen d a fr am e.

The CSMA/ CD access r ules ar e su m mar ized b y t he pr ot ocol' s acr ony m: The uCar pdatried of Each t he bst est selling onelist net w ork r ef rov ides cover age er edit senion se — at-ion contallinuinously ens f oring t r af ficerence on t hep m edium t o d et er mofin e essentwial an d cu t t ingedg e t ech nologies. hen gaps bet w een fr am e t r ansm issions occur . Mu lt i pl e access— St at ions m ay begin t r ansm it t ing any t im e t h ey det ect t hat t he n et w or k Con er veiew s oft rtaff echn is qucise iet (ov t her is no ic) .olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Coll ision de t e ct — I f t w o or m or e st at ions in t he sam e CSMA/ CD n et wor k ( collision New chapt er s include of im por tat ant likee VoI dom ain) begin t r ansmcov it t inerag g ateapp r oxim elyt opics t he sam t im P e, and t he EAP b it st r eam s f r om t he t r ansm it t ing st at ions w ill int er fer e ( collide) w it h each ot her, and bot h t r ansm issions w ill b e Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age un readab le. I f t h at h appens, each t ran sm it t ing st at ion m ust b e cap able of det ect ing t hat a collision has occur red befor e it has f inish ed sending it s f r ame. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Each m ust st op t r ansm it t ing as soon as it has det ect ed t he collision and t hen m ust w ait a I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat qu asir and om len gt h of t im e ( det erm ined by a back - off algor it hm ) befor e at t em pt ing t o enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing r et ran sm it t he f ram e. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . The w or st - case sit u at ion occur s w hen t he t wo m ost - dist ant st at ion s on t he n et w or k bot h n eed t o Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, sen d a fr am e an d w h en t he second st at ion d oes not begin t ran sm it t ing u nt il j ust b ef or e t he and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all fr am e f rom t he f irst st at ion ar r ives. The collision w ill be d et ect ed alm ost im m ediat ely by t h e net w or kin g p rof essionals, r egar dless of ex pert ise. second st at ion, but it w ill n ot be det ect ed by t h e fir st st at ion unt il t he cor r upt ed sig nal h as pr opag at ed all t he w ay back t o t hat st at ion. Th e m axim um t ime t hat is requ ir ed t o d et ect a Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e collision ( t he collision w indow , or " slot t im e" ) is app rox im at ely eq ual t o t w ice t he signal har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on pr opag at ion t im e b et ween t he t w o most - d ist an t st at ions on t he net w or k. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . This m eans t h at b ot h t he m inim um f r ame leng t h and t he m ax im um collision diam et er ar e Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy dir ect ly r elat ed t o t he slot t ime. Longer m inim um fr am e len gt hs t ran slat e t o long er slot t imes syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich and lar ger collision diam et er s; shor t er m inimu m f ram e lengt hs cor respond t o sh or t er slot t im es pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease and sm aller collision diam et er s. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions h eir netw ween ork s.t h e need t o r ed uce t he im pact of collision r ecov ery and t he n eed for The t rad e-for of f t w as bet net w or k diam et er s t o be lar ge enou gh t o accom m odat e r eason able net w or k sizes. The com pr omise w as t o choose a m ax imu m net w or k diam et er ( about 250 0 met er s) and t hen t o set t he min im u m fr am e lengt h long enoug h t o ensur e det ect ion of all w or st - case collision s. The com pr om ise wor k ed w ell f or 10 Mbp s, but it w as a pr oblem f or high er dat a- r at e Et hern et

dev elop er s. Fast Et h er net w as r eq uir ed t o pr ovid e backw ar d comp at ibilit y w it h ear lier Et her net net w or ks, in clud ing t he ex ist in g I EEE 802 .3 f ram e f or mat and er ror - det ect ion p rocedu res, plus all app licat ions and net w or king soft war e r un ning on t he 1 0- Mb ps net w or k s. Alt hou gh sig nal p rop agat ion velocit y is essent ially con st ant f or all t r an sm ission r at es, t he t im e r eq uir ed t o t r ansmit a f r ame is in ver sely r elat ed t o t he t ran sm ission r at e. At 1 00 Mbp s, a m inim um - len gt h fr am e can be t r ansm it t ed in app rox im at ely one- t en t h of t he d ef ined slot t im e, and any collision t h at occur r ed du rin g t h e t r ansm ission wou ld n ot lik ely b e det ect ed by t he • Table of Content s t r ansm it t ing st at ions. This, in t ur n, m eant t hat t he max im um n et w or k diam et ers sp ecified for • I ndex 10 - Mbp s net w or ks could not be u sed for 100 - Mbp s net w or ks. Th e solu t ion f or Fast Et hern et w as I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion t o redu ce t he m ax im u m net w or k diam et er b y app rox im at ely a fact or of 1 0 ( t o a lit t le mor e t han By 20 Cisco 0 m etSystems, ers) . Inc. ThePub sam ob lem lishe er:prCisco Pressalso ar ose du rin g specificat ion d ev elopm en t f or Gig abit Et hern et , bu t decreasing net w or k diam et er s by anot her f act or of 10 ( t o appr ox imat ely 20 m et ers) for 1 000 Pub Dat e: Sep tem ber 1 1, 2 003 Mb ps oper at ion was sim ply n ot p ract ical. This t im e, t he developers elect ed t o m ain t ain I SBN: 1- 58 705 -1 19 -2 app rox im at ely t he sam e m axim um collision dom ain diam et er s as 1 00- Mbps net w ork s an d t o Pages: 11 28 incr ease t h e appar ent m in imu m fr am e size by ad ding a var iable- len gt h nond at a ex t ension f ield t o fr am es t hat are sh ort er t h an t he m inim um leng t h ( t he ext en sion field is rem ov ed du rin g f r ame r ecept ion) . Figur e 8- 7 sh ows t he MAC f ram e f or mat w it h t he g ig abit ex t ension f ield, and Table 8 - 1 sh ows tThe he ef fect of h e tion r adew een t h e tallr ansm ission a rat t he mpinim um fcover r am eage sizeoff or u pdat ed tedit of off t heb betest - selling in- one netdat w ork inge rand ef erence rov ides 10 - Mbp 100 Mbps, d e100 0-nologies. Mbp s Et h er net . essent ials, an d -cu t t ing-an edg t ech Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice Figu t o ex pert r e .8 - 7 . M AC Fr am e w it h Giga bi t Car r i er Ext en si on New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain Tab a g reat un der anitding of LAN w or k ing, p ar t icu lar ly t h e le er 8 -1 . Listm s f or Ha lfand -D WAN up lenxetOpe r a t ion har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

P ar am e t er

1 0 M bps

1 0 0 M bps

1 0 0 0 Mbp s

Minim um fr am e size

64 by t es

64 by t es

52 0 b yt es [ 1] ( wit h ex t en sion field added)

Max im um collision diam et er , DTE t o DTE

10 0 m et ers UTP

10 0 m et ers UTP

10 0 m et ers UTP 31 6 m et ers fiber

•

Table of Content s

•

I ndex

41 2 m et ers fib er

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Max im um collision diam et er w it h r ep eat er s

25 00 m et er s 20 5 m et ers

20 0 m et ers

Max im um m ber Pub lish er: nu Cisco Pressof r ep eat er s in netPub w orDat k e: pat h Sep tem ber 1 1, 2 003

5

1

By Cisco Systems, Inc.

2

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

[ 1]

520 bytes applies to 100 0Base- T implem entations. The m inim um fr am e size w ith ex tension field for 1000Base- X is redu ced to 416 bytes becau se 1000Base-X encodes and tr ansm its 10 bits for each by te.

Anot h er ch ange t o t h e Et her net CSMA/ CD t r ansm it specif icat ion w as t h e add it ion of f ram e bu rst ing f or gigab it oper at ion. Bu r st m ode is a feat ur e t h at allow s a MAC t o sen d a shor t seq a bedit ur stion ) ofoff ram equal t o ap prinoxim ely w5.ork 4 m axim um - lengt h f ides ram es w it hou Theuence u pdat (ed t he es b est - selling alloneatnet ing r ef erence p rov cover aget of hav ingial t o an relinqu of t nologies. h e m ed iu m . The t r an sm it t ing MAC fills each in t er f ram e int er v al essent d cu t tish ing-cont edgreolt ech w it h ex t ension b it s, as show n in Figur e 8- 8 , so t hat ot her st at ions on t he net w ork will see t hat t he net w ork is busy and w ill not at t em pt t r ansmission u nt il af t er t he b ur st is com plet e. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er sFigu include im por opics VoI andqu EAP r e cov 8 -erag 8 . Ae of Giga bittant Frtam e -like Bur stP Se en ce Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e I f t he lengt h of t h e fir st f r ame is less t han t h e m inimu m f ram e lengt h, an ext ension field is ad ded har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on t o ex t end t he f r am e len gt h t o t h e v alu e indicat ed in Table 8 - 1. Su bseq uent fr am es in a fr am ea b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions bu rst sequ en ce do n ot n eed ext ension fields, and a f r ame bur st m ay cont in ue as long as t he t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . bu rst lim it has not been reached. I f t he bur st lim it is r each ed af t er a f r ame t ran sm ission has Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy begu n, t r ansm ission is allowed t o con t inue u nt il t h at ent ir e f ram e h as been sent . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals operf ields at e. Tools and id elines imode izing per m ance w ill an incr Fram e ex t ension are not d efgu ined, an d fboruropt st m is syst not em allow edfor f or 1 0 Mbps d ease 1 00 Mbp s pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient t r ansm ission rat es. decisions for t h eir net w ork s.

Full-Duplex Transmission—An Optional Approach to Higher Network Efficiency Full- dup lex op er at ion is an opt ional MAC cap abilit y t hat allow s sim ult an eou s t w o- w ay

t r ansm ission over p oin t - t o- poin t link s. Full du plex t r ansmission is f unct ionally m uch simp ler t han half - dup lex t r an sm ission because it in volv es no m edia con t en t ion, n o collisions, no need t o sch ed ule r et ran sm ission s, and no need f or ex t ension bit s on t he en d of shor t fr am es. Th e r esult is not only m or e t im e av ailab le for t r an sm ission, but also an effect iv e doub lin g of t he link ban dw idt h because each link can now sup por t f ull- r at e, sim u lt an eou s, t w o- w ay t r ansm ission. Tr ansm ission can usually b eg in as soon as f ram es ar e r ead y t o send . The on ly rest r ict ion is t hat t her e m ust b e a m inim um - lengt h int er f ram e g ap b et w een su ccessiv e fr am es, as sh ow n in Figur e • Table of Content s 8- 9 , an d each fr am e m ust conf or m t o Et her net f ram e f or mat st and ard s. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 8 - 9 . Fu ll Du pl ex O pe r at ion Al low s Si m ul t a ne ous Tw o-W a y Tr an sm issi on on t he Sam e Li nk

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

FlowNew Control chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Full- dup opeerofatcut iont ing r eq uir es con cu ologies rr ent imp ent at ion t he op tand ional low - con t r ol capabilit y Covlex erag edge t echn liklem e opt ical n etof wor k ing st for age t hat allow s a r eceiv in g node ( su ch as a net w ork sw it ch por t ) t hat is becom ing congest ed t o r eq uest Autthhored e send bying Cisco node Sy(st suems, ch aswaorfile ldwserv ide leader er) t o st inopnet sending w or kingf ram f or es t hef or I n taerselect n et . ed sh ort per iod of t im e. Con t r ol is MAC- t o- MAC t hr ough t h e use of a p ause fr am e t h at is au t omat ically I n t ernat eted w orbkyint he g Tech nologies Hand , Four t hion Edis it ion , ised a com preehensive refer gener r eceiv ing MAC. I f book t h e congest r eliev b ef or t he r equest edence w aitt hat has enables w or kin g p r ofessionals derst and encan t cont portar intuest er net w ork ing exp ired, net a second p ause fr am e w itt ho aunzer o t im e- an t o-dwim aitplem v alue beem sent o yr eq r esu mp t ion t echnologies. Mast er mof s, tcon t echn an is d devices inet oday of t r ansm ission. Anerovt he ervtiew he cep f lowt s,cont r ol ologies, op er at ion show n inused Figur 8- 1 0.' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all netFigu w or kinr ge p8rof r egar ex tpert - 1essionals, 0 . An Ov er vdless ie wofof heise. I EEE 8 0 2 .3 Flow Con t r ol Sequ en ce Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

•

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The f ull- du plex operat ion an d it s com pan ion f low cont r ol capab ilit y ar e b ot h opt ions f or all Et h er n et MACs an d all t r ansmission r at es. Bot h opt ions are en abled on a link - b y- link b asis, assu in g ed t hatedit t he associat phy sical layer s one ar e also supp orpt ing full- dcover uplexage of The umpdat ion of t he ed b est - selling all- innet wcapable ork ing r of ef erence rov ides oper at ion. essent ial an d cu t t ing- edg e t ech nologies. Pause f ram es ar e ident if ied as MAC cont r ol f r ames b y an ex clu siv e assig ned ( reser v ed) lengt hCon / t ypcise e v alu e.v They ar et echn also olog assign a r eserv dest ionprad dr ess vals alue o ensur e tfhat ov er iew s of ies ed essen t ial t oedn et worinkat ing ofession at tall lev els, roman incomnov ingice pause f ram e is n ev er for w ar ded t o u pper pr ot ocol lay ers or t o ot her por t s in a sw it ch. t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Frame Reception Cov erag e of cut t ing

edge t echn ologies lik e opt ical n et wor k ing and st or age

Fram eAut r ecep t ion essent t h e wsame ot h halfuplex ll- dup opner h ored byisCisco Syially st ems, or ldwfor idebleader in dnet w orand king fuf or t he lex I n t er etat . ions, ex cept t hat f ull- dup lex MACs m ust h ave separ at e f ram e b uf fers and dat a pat hs t o allow f or simu lt et aneous e t rnologies an sm ission and r ecept ion I n t ern w or k inf ram g Tech Hand book , Four t h. Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Fram e r ecep t ion is er t h tehe r ev erm ses,ofcon f r ame t ran sm ission . The inat ionused ad driness of t 'hsenet r eceiv t echnologies. Mast t er cep t s, t echn ologies, an dd est devices t oday w orked ing fr am e is checked and m at ched ag ainst t h e st at ion's addr ess list ( it s MAC addr ess, it s gr oup indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . add t h e br ad dr ess)ert os det miniteyw het t he am enet is wdest f or t hat y, Comresses, plet e wan it hd new anoadcast d u pdat ed chapt on er secur , st orher age, optfrical or kin ined g, scalabilit st at ion. I f an add ress m at ch is f oun d, t h e fr am e len gt h is check ed and t he r eceiv ed FCS tisial t o all and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen com par ed t o t he FCS t hat w as gener at ed du r in g fr am e recept ion. I f t h e fr am e len gt h is ok ay and net w or kin g p rof essionals, r egar dless of ex pert ise. t her e is an FCS m at ch, t he f ram e t y pe is det er m ined by t h e con t ent s of t h e Lengt h/ Ty pe f ield. The f r am e ill is obt t hen sed and f orw t o t hofe LAN app rop e upper Reader sw ainpar ag reat er un derarstded an ding andriat WAN n et wlay or ker. ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tThe o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . VLAN Tagging Option Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich VLAN t aggin g oper is a at MAC opt ionand t hat ides f tor hr opt ee imp or t ant cap n ot p rev sly ease available pr of essionals e. Tools gupr id ov elines im izing syst emabilit per ies for m ance w iou ill incr tpr o odu Et her net n et wor k u ser s and net w or k m anager s: ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Pr ovid es a m ean s t o ex pedit e t im e- crit ical n et w or k t r aff ic by set t ing t r ansm ission pr iorit ies for out goin g f r ames. Allow s st at ions t o be assig ned t o logical gr ou ps, t o com m unicat e acr oss mu lt iple LANs as t hou gh t hey w ere on a sin gle LAN. Brid ges and swit ches f ilt er dest in at ion ad dr esses and

for w ar d VLAN f r ames on ly t o p ort s t hat ser ve t he VLAN t o wh ich t h e t r aff ic belon gs. Sim plifies net w or k m anagem en t an d m ak es adds, m ov es, and ch anges easier t o adm inist er. A VLAN- t agged fr am e is sim ply a b asic MAC d at a f r ame t hat has had a 4- by t e VLAN header insert ed bet w een t h e SA and Len gt h/ Ty pe field s, as show n in Figur e 8- 1 1. •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Figu r e 8 - 1 1 . VLAN- Ta gge d Fr am e s Ar e I de nt if ie d W h en t he M AC Fi nds t h e LAN Ty pe Va lu e in t he N or m a l Le ngt h/ Ty pe Fi el d Locat ion

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The VLAN header consist s of t w o f ield s: Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom A r eser - by t. e t y pe v alue, indicat ing t h at t h e fr am e is a VLAN f ram e nov ice tvoedex2pert A t woby t eerTagCon t r ol field t ains b ot h t he like t r ansm iorit y ( 0 t o 7, wh er e 7 is New chapt s include cov eragt hat e of con im por t ant t opics VoI ission P and pr EAP t he highest ) an d a VLAN I D t h at ident if ies t he p art icular VLAN ov er w hich t h e fr am e is t o be Covterag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age sen The r eceiv Aut h ored ing MAC by Cisco readsSy t he st ems, r eserwv ed or ldw t y pe idev leader alue, win hich netis w or locat king edf or in t he nor I n t er mnaletLen . gt h/ Typ e field posit ion , and int er pr et s t he receiv ed f r ame as a VLAN fr am e. Then t he f ollowin g occur s: I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing I f t he MAC is er instt he alled a sw ch por , t h eologies, fr am e isan for ar ded accor t o it' s pr ior y lev t echnologies. Mast t er in m s, conitcep t s, t echn d wdevices used ding in t oday net w itork ingel t o all por t s t h at ar e associat ed w it h t h e indicat ed VLAN ident if ier . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, I f t he MAC is instisalled in plet an end ion , d it at rem oves t h e 4eadare er and pr ocesses and speed, t h is book a com e an st d at u pt oe r ef er ence t o bt yt hee t VLAN op ics thhat essen t ial t o all t he fr am e in t he sam e m anner as a basic dat a fr am e. net w or kin g p rof essionals, r egar dless of ex pert ise. VLAN r equir t haterallun net w st oran k nod volv and ed wWAN it h a nVLAN e equipp edt hweit h t he Readert aggin s w ill gobt ain aesg reat der dingesofinLAN et w orgkrou ing,p pb ar t icu lar ly VLAN har dw opt ar e,ion. pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

The Ethernet Physical Layers Becau se Et her net d ev ices im plem en t on ly t he b ot t om t w o lay er s of t he OSI pr ot ocol st ack, t hey ar e t y pically im plem en t ed as net w ork in t er f ace car ds ( NI Cs) t hat plug int o t he host dev ice' s m ot her boar d. Th e diff erent NI Cs ar e ident if ied by a t hr ee- par t p rod uct n ame t hat is based on t he •ph ysical layerTable of Content at t rib ut es. s •

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IThe nt e rn w or Tevent chnologie ndbook Fourion th Edit n et am inkging con ion iss Haa con cat ,enat of ion t h ree t er m s indicat ing t he t ran sm ission r at e, t he tBy r ansm ission met h od, and t h e m ed ia t y pe/ sig nal encodin g. For exam p le, consider t h is: Cisco Systems, Inc.

Pub10 lishBaseer: Cisco T =Press 10

Mb ps, baseband , ov er t wo t w ist ed - pair cables

Pub Dat e: Sep tem ber 1 1, 2 003

10 0Base100 I SBN: 1- 58T2 705 = -1 19 -2 Mb ps, baseband , over t wo t w ist ed - pair cables Pages: 11 28

10 0Base- T4 = 100 Mb ps, baseband , over f our - t w ist ed p air cab les 10 00Base- LX = 10 0 Mbps, baseban d, long w av elengt h ov er opt ical f iber cable A q uest ion som et im es ar ises as t o w hy t he m iddle t er m alw ay s seem s t o b e " Base. " Ear ly vThe er sions u pdatofedt hedit e prion ot ocol of t he also b est allow - selling ed f orallbr inoadb one and nett w r ansmission ork ing r ef erence ( f or exam p rovpides le, 1cover 0Br oad) age, of b ut essent br oadbial and animp d culem t t ingentedg at ion e st ech w ernologies. e n ot successfu l in t he m ar ket place. All cur r en t Et hern et im plem ent at ion s use baseband t r ansm ission. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Encoding for Signal Transmission

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP I n baseb and t r ansmission, t h e fr am e inf orm at ion is dir ect ly im pr essed upon t h e lin k as a Cov erag e lses of cut t echn e ically opt ical et wor k ing and st orinage seq uence of pu ort ing d at edge a sy mb ols tologies hat are lik t yp atnt enu at ed ( r educed size) and d ist or t ed ( chang ed in shape) b ef or e t hey r each t h e ot her end of t he link . Th e r eceiver 's t ask is t o det ect h ored Sy sttems, ideitleader in net king ef or t he er I nrting er n et . r econ st ru ct ed each Aut p ulse as itby ar Cisco r ives and h en t w o or exldw t r act s cor r ect valuweorbefor t r ansf t he inf orm at ion t o t he r eceiv in g MAC. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables netpwulseor kinshap g p r in ofessionals t o unhelp derst and plem en tshape cont em int er net orkorm ing s, Filt er s and g cir cuit s can r est or an e tdheimsize and ofpor t h earr yeceived ww avef tbu echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t ad dit ional m easur es m u st be t aken t o ensur e t h at t h e r eceived sig nals ar e samp led at t he indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . corr ect t im e in t he p ulse per iod and at same rat e as t he t ran sm it clock : Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kinrgeceiv p rofeessionals, of ed ex pert The clock m u rstegar be dless r ecover f romise. t he incom ing dat a st ream t o allow t he receiv ing ph ysical layer t o syn ch ron ize w it h t he incom ing pulses. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dwCom ar e,pensat pr ot ocols, v ices olvt ak eden . Fufor ndam al t ech nology or mat ionbaselin is pr oveided on ing mand easuser res m ustinvbe a t rent ansmission ef fectinf k now n as a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions w and er . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Clock r ecov es ed level ansittions in nt hetewor incomin sign alt s,t obut id en t ify tan d sy onize on Cov erag e isery alsor equ extirend n ott ronly o new k ing g concep also o old ernchr , legacy pu lse ound aries. ing ic1 spict and t h erealfr amweorpr ble ere en d esign ed ent botshint ow hich syst emb s, pr ovid in gThe a malt orer e nat r ealist ur e0sofoft he ldeam n et w or kwing vir onm indicat e t h at aoper fr am as ar rand iv ingguand t o aidf or in opt clock recover y .em How evfor er,mrecov ed incr clocks pr of essionals atee.wTools id elines im izing syst per ance er w ill easecan dr lose syench izat ion if ing pu lse els r em t h er, ecost ar e- eff noicient pr ift oduand ct iv possibly it y an d im pr ov eff ron iciency, help t helev r eader main akeconst mor eant in tand elligent tdecisions r ansit ionsfor t o t det exs.am ple, du rin g lon g st r ings of 0s) . h eirect net( fworork Baseline wan der r esult s becau se Et her net link s ar e AC- coup led t o t he t r an sceiv er s and because AC cou pling is incapable of m aint ain in g volt ag e lev els for m or e t h an a shor t t im e. As a result , t r ansm it t ed p ulses ar e d ist or t ed by a dr oop ef fect similar t o t he ex agg er at ed ex am ple show n in Figur e 8- 1 2. I n long st rin gs of eit her 1s or 0s, t he dr oop can becom e so sev ere t hat t he v olt age

level p asses t hr oug h t he decision t hr eshold, r esult ing in er r oneous sam pled v alues for t he aff ect ed pu lses.

Figu r e 8 - 1 2 . A Con ce pt Exa m ple of B asel in e W an de r •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Fort unat ely , en coding t he ou t going signal befor e t r ansm ission can signif ican t ly redu ce t he eff ect of botNew h t h ese p rob s, as cov w ellerag as reedofuce t he t ant possib ilit y like of t rVoI ansm ission err or s. Ear ly Et h er net chapt er slem include im por t opics P and EAP im plem ent at ion s, up t o an d in clu ding 10Base- T, all u sed t he Manchest er encod in g m et hod , edge t echn ologies k ingion and or age show nCov in erag Figureeof8-cut 1 3.t ing Each pu lse is clear ly idlik ene t opt ifiedical b yntet hewor direct of st t he m idpu lse t ran sit ion r at her t h an b y it s sam pled level v alue. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w orrkin g -p1r ofessionals t o ionun derst im plem y int er net w ork ing Figu e 8 3 . Tr a nsit Baand se danMd an che en st tecont r Biem napor r yarEncodi ng t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions t h Manchest eir net w ork Unfor t u natfor ely, er s. en cod in g in t r oduces some d iff icult fr equency - r elat ed pr oblem s t hat m ake it un su it able f or use at higher d at a r at es. Et h er net ver sion s su bsequent t o 1 0Base- T all use dif fer en t encoding pr ocedur es t hat include som e or all of t he f ollow ing t echniqu es: U si ng da t a scr am bl in g— A pr ocedur e t h at scram bles t h e bit s in each by t e in an or derly

( and r ecov erab le) m anner . Som e 0s ar e chan ged t o 1s, som e 1s are ch anged t o 0 s, and som e bit s ar e left t he sam e. The r esu lt is r educed r u n- len gt h of sam e- v alue b it s, in cr eased t r ansit ion densit y, an d easier clock r ecov ery . Ex pa ndi ng t he code spa ce — A t echniqu e t hat allows assign ment of sep arat e cod es for dat a and cont r ol sy mb ols ( such as st art - of - st r eam and en d- of - st ream d elim it er s, ext en sion bit s, an d so on) an d t hat assist s in t ran smission er ror det ect ion. •

Table of Content s U si ng for w a rd e rr or- corr ect i ng cod es— An encodin g in w hich redu ndan t inf or mat ion is add ed t Iondex t he t r an sm it t ed dat a st r eam so t h at som e t y pes of t r ansm ission er r or s can b e I nt e rn corr et w or k ing s He a ndbook Four th Edit ion ect ed Te d chnologie ur in g fr am r ecept, ion. •

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

NO TE

I SBN: 1- 58 705 -1 19 -2

Pages: Forw ar11 d 28 err or - corr ect ing cod es are u sed in 100 0Base- T t o achiev e an ef fect ive r ed uct ion in t h e bit er r or r at e. Et h er net pr ot ocol limit s er r or han dling t o d et ect ion of bit err or s in t he r eceiv ed f ram e. Recov er y of f ram es r eceived w it h uncor rect able er ror s or m issing f ram es is t he responsibilit y of hig her layer s in t he pr ot ocol st ack .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

The 802.3 Physical Layer Relationship to the ISO Reference Model Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Alt hounov gh ice t het ospecific m odel of t h e phy sical layer m ay v ar y fr om v ersion t o v ersion, all ex pert logical . Et h er n et NI Cs gener ally con for m t o t he g en er ic m odel show n in Figur e 8- 1 4. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Figu r e 8 - 1 4 . Th e Gen er i c Et he r ne t Phy si cal Lay er Re fe r e nce M od el Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP The p hy sical lay er for each t r ansmission r at e is d ivided int o su blay er s t h at ar e ind ep en dent of Cov erag t echn ical icn et oror age t he par t icu lar emof edcut ia t ying pe edge and sub layologies er s t hatlikareeopt sp ecif t owor t h ek ing m edand ia t yst pe sign al encoding. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The r econciliat ion sublay er and t he op t ional m edia- ind ep en dent in t er f ace ( MI I in 10- Mb ps I n t ernand et w or inMb g Tech , Four h hEd isov a ide comt he pr ehensive refer ence t hatw een 10k0ps Etnologies hern et , Hand GMI I book in Gigab it tEt er itn ion et ) ,pr log ical con nect ion bet enables w orand kin gt he p r ofessionals unm derst and an d im plem ens.t cont ar yGMI int er net ork t henet MAC d if fer en t sett o s of ediadependent lay er The em MI Ipor and I ar ew def ining ed t echnologies. Mast t hesm t er s, con cepet s,d at t echn ologies, oday w it h separ at eert ran it mand receiv a pat hs t h at an ar de devices bit - ser ialused for 1in0-tMb ps' s net w ork ing indu stim ryplem . Learent n at how o incor porser atial e int in t lem o a ent LAN/ onm ionts, nibble( 4erbnet it s wwor id kin e) fgort echn 100 -olog Mbpies s imp at WAN ion s, env andirby t e-ent ser.ial Com plet e ws itwhide) newfor an1d000 u pdat ed schapt er sent onatsecur y , estm ored age, opt ical net w or k er in g, scalabilit y, ( 8 bit - Mbp imp lem ions.itTh ia- in dependent int faces and t he and speed, t h is ion book a com e an u pd at er esp r ef erect ence t he tission op ics trat hatesare essen r econciliat su is blayer arplet e com mdon f ort o-t heir iv e t roansm an d ar e t ial t o all net w or kinig g ur p rof r egaroper dlessatof ise. T and all sub sequ en t Et hern et v er sions. conf ed essionals, f or fu ll- duplex ionexinpert 1 0BaseReader s wmillediaobt ain reat erp hy unsical der stcodin an ding of LAN WAN n etides w or tkhe ing, p ic ar tfor icu encodin lar ly t h eg, The d epaeng dent g sub layerand ( PCS) pr ov log har dwmarult e,iplexin pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion ided on g, an d sy nchr onizat ion of t he ou t going sym b ol st r eam s as w ell syis mbprolovcode a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions alignm ent , demu lt ip lex ing, and decoding of t he in com ing dat a. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag Thee pishyalso sicalext m end edium ed natott achm only en t o t new ( PMA) n etsublay wor k ing er concep cont ains t s,t he butsignal also t ot ran oldsm er ,it legacy t er s and syst em r eceiver s, pr ovid s ( in t r ansceiv g a m orers) e r ealist , as w icell pict asurt e heofclock t he realrecover w oryldlogic n et wf or kting he receiv en vir onm ed dent at as st inr eams. w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease myedium - dpr epov enedent in t erf ace ( MDI is trhe cable connmor ect or w een t, he signal pr oduThe ct iv it an d im eff iciency, help ing )t he eader m ake e inb tet elligent cost - eff icient t r ansceiv d wt he decisions for t hers eir an net orklink s. . The Au t o- negot iat ion sublay er allow s t he NI Cs at each end of t he link t o ex ch ange inf orm at ion abou t t h eir in divid ual capab ilit ies, and t hen t o n eg ot iat e and select t h e m ost fav or able op er at ional mod e t hat t hey b ot h ar e capab le of su ppor t ing . Aut o- n eg ot iat ion is opt ion al in ear ly Et h er n et imp lem ent at ions and is m andat or y in lat er v er sions.

Depend in g on w h ich t y pe of signal en cod ing is used an d h ow t he lin ks ar e conf igur ed, t he PCS and PMA m ay or m ay not be capab le of su ppor t ing f ull- dup lex op er at ion.

10-Mbps Ethernet—10Base-T 10 Base- T pr ovides Manchest er - encoded 1 0- Mb ps b it - ser ial comm u nicat ion ov er t w o u nshield ed •t w ist ed - pair cables. Table of Content s h t he st andar d w as designed t o sup por t t ran sm ission ov er com m on Alt houg •t elep hone cable, I ndext h e m ore t yp ical lin k con figu r at ion is t o use t w o pair of a f our - pair Cat egor y 3 Ior nt e5rncable, et w or k ing Teinat chnologie H a ndbook Four t erm ed ats each NI C, w it hthanEdit 8-ion pin RJ- 4 5 con nect or ( t he MDI ) , as show n in Figur e 8- 1Cisco 5. Because By Systems, each Inc. act ive pair is conf ig ur ed as a sim p lex link w h er e t r ansm ission is in one dir ect ion only , t h e 10Base- T p hy sical lay er s can supp ort eit her half - dup lex or f ull- du plex operPub atlish ion. er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 Figu r e 8 - 1 5 . Th e Ty pi cal 1 0 B ase- T Link I s a Four - Pa ir U TP Ca ble i n W hi ch Tw o Pai r s Ar e N ot U se d

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst emgh s, pr ovid in gT a ealist ur e oft ially t he realw oreldinn some et w or kcir ing en vir entded s in hwerhich Alt hou 10Basemm ayorbee rcon sidicerpict ed essen ob solet cles, it onm is in clu e pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr because t her e ar e st ill m any 10 Base- T Et her net n et w or k s, and because fu ll- d uplex operease at ion has pr iv it y an danimex prt ended ov e eff life. iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient givodu en ct 1 0BaseT decisions for t h eir net w ork s. 10 Base- T was also t he f irst Et her net v er sion t o in clu de a lin k int egr it y t est t o det er m ine t h e healt h of t he link . I m m ed iat ely af t er pow eru p, t h e PMA t ran smit s a nor m al link p ulse ( NLP) t o t ell t he NI C at t he ot h er en d of t h e link t h at t h is NI C w ant s t o est ablish an act ive lin k con nect ion :

I f t he NI C at t h e ot her end of t h e lin k is also pow er ed up , it r espond s w it h it s own NLP. I f t he NI C at t h e ot her end of t h e lin k is not pow ered up , t his NI C con t inues sending an NLP abou t on ce ev er y 1 6 ms unt il it r eceives a response. The link is act iv at ed only aft er b ot h NI Cs ar e capable of exch anging v alid NLPs. •

Table of Content s

100 Mbps—Fast Ethernet • I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

IByncr easing t he Et her net t r an sm ission r at e by a fact or of t en ov er 10Base- T w as n ot a sim ple Cisco Systems, Inc. t ask , and t he ef for t result ed in t h e developm ent of t hr ee separ at e p hy sical lay er st andar ds f or 10 0 Mbps ov er UTP cable: 1 00Base- TX and 1 00Base- T4 in 19 95, and 100 Base- T2 in 199 7. Each Pub lish er: Cisco Press w as def in ed w it h diff erent encoding r eq uir em ent s an d a dif fer en t set of m edia- depend en t Pub ers, Dat e: ev Sep temt h ber 1 1, 2t003 sublay en ough her e is som e over lap in t h e lin k cabling. Table 8 - 2 com par es t he I SBN: 158 705 -1 19 ph ysical layer char act-2 erist ics of 10Base- T t o t he var ious 1 00Base v ersions. Pages: 11 28

Tab le 8 -2 . Sum m a r y of 1 0 0 Ba se - T Phy sica l Lay e r Cha r act er i st ics The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ialetan d cu tTra t ingedgite Sy t ech Et he rn nsm mnologies. b ol Full - D up le x [ 1 ] V e rsion Ra t e Encodi ng Cab lin g Ope r at i on Con T cise ov er s of t echn olog ies ial tTw o noetpwor pr ofession allpor levtels, 10 Base10v iew MBd Manessen ch estt er airsk ing of UTP Cat egorals y atSup ed f rom nov ice t o ex pert . –3 or b et t er 10 0BaseTX er 12s 5include MBd cov erag e 4B/ 5 Bpor t ant Tw o p airs UTP CatEAP egor y Sup por t ed New chapt of im t opics like of VoI P and –5 or Ty pe 1 STP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age 10 0Base- T4 33 MBd 8B/ 6 T Four p air s of UTP Cat eg or y Not su ppor t ed b et erking f or t he I n t er n et . Aut h ored by Cisco Sy st ems, w or ldw ide leader–3inornet w tor 10 0Base- T2 25 MBd PAM5x 5 Tw o p airs of UTP Cat egor y Sup por t ed I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat –3 or b et t er enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . [ 1] = one itted bol per w her ansmitopt tedical sy mbol may the equivalent Com pletOn e ew baud it h new antrdansm u pdat edsym chapt er s second, on secur it ye, th steortrage, net w or kcontain in g, scalabilit y, value of 1 or mor e binar y bits. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w orgh kinnot g p rof of exw pert Alt hou all essionals, t hr ee 100 r- egar Mbp sdless v er sions ereise. su ccessf ul in t he mar k et place, all t hr ee hav e been d iscussed in t he lit er at ur e, and all t h ree d id im pact fut u r e desig ns. As such, all t hr ee are Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e im por t ant t o consider h er e. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . 100Base-X Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich 10 0BaseX w as desig t o sup ansm ission eit her o pair s of egor 5 UTP copper pr of essionals oper at e.ned Tools andpor gutidt relines f or optov imer izing systt w em per for m Cat ance w illy incr ease w t witoy st r and ofov opt icaliciency, f ib er . Alt h ough t h er eader en cod ing, decod d clock r ecov y prire oduorct iv an d ims pr e eff help ing t he m ake mor in e g, in tan elligent , cost - effericient pr oced ur es t henet sam e for decisions forart e h eir w ork s. bot h m ed ia, t he sign al t r ansm ission is diff er ent —elect r ical pu lses in copper an d ligh t p ulses in opt ical f iber. The signal t r ansceiv er s t h at w er e inclu ded as par t of t he PMA fun ct ion in t he g en er ic logical m odel of Figur e 8- 1 4 w er e r ed ef ined as t he separ at e ph ysical m ed ia- dependent ( PMD) sublay ers sh own in Figur e 8- 1 6.

Figu r e 8 - 1 6 . Th e 1 0 0 Ba se - X Log ica l M odel

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat The 1 00BaseX kin encodin g p rocedurteo is asedand on tan hedear FDD opt ical f ib er enables net w or g p r ofessionals unbderst im lier plem en t I cont em por ar yphy intsical er netmediaw ork ing depend en t an d FDD I / CDDI copp er t w ist edp air phy sical m ed iad ep en dent sig naling st andar t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w orkds ing dev elop ed by I SO and ANSI . The 1 00BaseTX p hy sical m ediadepend en t sublay er ( TPPMD ) w .as indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent im plem it h CDDI orert sr an erits yand RJ4 5 con nectnet or s;w or t he PMD w as Com pletent e wed it hwnew an d usem pdaticon ed duct chapt onsceiv secur , st or age, opt ical k infib g,erscalabilit y, im plem ent ed w it h FDD I opt ical t r ansceiv er s and t he Low Cost Fib re I n t er f ace Connect or t ial t o all and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen (net com mon t he d uplex SCdless con nect orpert ) . ise. w or kinly g pcalled rof essionals, r egar of ex The 4 B/s5B codain in gapr ocedu t he sam e as h e enand cod WAN ing prnoced urkeing, used b yt icu FDlar DIly , wt hiteh only Reader w illenobt g reat er re unisder st an ding of t LAN et w or p ar m inor ade, apt t o and accom hered net f rndam am e con t r ol. Each 4- bitinfdat a nibble repr in g har dw ar prat otions ocols, sermv odat ices e invEtolv . Fu ent al t ech nology or mat ion is( pr ovesent ided on half of a rdat yt e) is malapped intsoand a 5-serv b it bices, in aryincod g rou p ailed t hat descr is t r ansmit edrev bitiew - serial over a b r oad angaebof int egr sy st em clude-ing det ipt ionts, quest ions tt he pr ovr et ided y t he 3 2ad5-dit bitional cod egr oups o enlinsuk.reThe conexp ceptanded compcode r eh enspace sion and en tbion, and r esou r cesallow f or fusepar rt her at steudy . assig nm e enis t falso or t he Cov erag extfollow end eding: n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease The 1 6 possib le values in a 4 - bit dat a n ibble ( 1 6 code- g rou ps) . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Four cont r ol cod e- g rou ps t h at ar e t r ansm it t ed as cod e- g r oup pair s t o in dicat e t he st ar t - of st r eam delim it er ( SSD) and t he end - of- st r eam delimit er ( ESD) . Each MAC f ram e is " encapsulat ed" t o m ar k bot h t h e beginn in g and en d of t he f ram e. The fir st by t e of p ream ble is r ep laced w it h SSD code- gr oup pair t hat pr ecisely ident if ies t he f ram e's cod e- g r oup bou ndar ies. The ESD code- gr oup pair is ap pended aft er t he f ram e's FCS field.

A special I DLE code- gr oup t h at is cont in uously sen t d ur ing in t erf r ame gaps t o m aint ain cont inu ous sy nchr onizat ion bet w een t he NI Cs at each end of t h e lin k. The r eceipt of I D LE is int er pr et ed t o mean t hat t he lin k is quiet . Elev en inv alid code- gr ou ps t hat ar e not int ent ionally t r an sm it t ed by a NI C ( alt hou gh one is used by a r epeat er t o pr opagat e receiv e er ror s) . Receip t of an y inv alid code- gr oup w ill cause t he in com ing f ram e t o be t reat ed as an in valid fr am e. •

Table of Content s Figur e 8- 1 7 sh ows how a MAC fr am e is encapsulat ed b ef or e being t r ansm it t ed as a 100 Base- X •code- gr oup st I ndex r eam . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 8 - 1 7 . Th e 1 0 0 Ba se - X Code- Gr ou p St r e am w i t h Fr am e Encapsu la t ion Pub Dat e: Sep tem ber 1 1, 2 003

Pub lish er: Cisco Press

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

[ View full size im age]

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age 10 0Base- TX t r ansm it s and r eceives on t he sam e link p air s an d uses t he sam e pin assign ment s on t heAut MDI as 1by 0BaseBase-wTX an dide 100 Base-in FXnet botwhorsup porf or t htalffu ll- d uplex h ored CiscoT.Sy100 st ems, or ldw leader king he du I n tplex er n etand . t r ansm ission. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing 100Base-T4 indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet eT4 w itwhas new d ued pdat chapt s on secur it yk,sstt oorbe age, ical net or kMb in g,psscalabilit y, 10 0Based evan elop t o ed allow 10er BaseT n et wor up opt gr aded to w 1 00op er at ion and speed, t h is book ising a com plet e an d egor u p- tyo-3d at e r cables ef er ence op ics wit t hat essen w it hout r equir ing ex ist fou rp air Cat UTP t o tboet he r eptlaced h tare h e new ert ial t o all net w or kin p rof essionals, dless of sex ise. Cat egor y 5g cables. Tw o of rtegar he four pair arpert e con figu red for half- d uplex oper at ion and can supp ort t r ansm ission in eit her d ir ect ion , bu t on ly in on e dir ect ion at a t im e. The ot h er t wo pair s Reader s wur ill ed obtas ainsim ag reatpair er un der st aned ding LAN and WAN n et orect k ing, ar t icu lar lyet h e ar e config plex s dedicat t o of t r ansm ission in on ew dir ion ponly . Fram har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion pr ov t r ansm ission uses bot h half- duplex pair s, plu s t he sim plex pair t h at is ap pr opr iat eisfor t heided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew t r ansm ission dir ect ion, as sh ow n in Figur e 8- 1 8. Th e sim plex pair for t h e opposit e d ir ectquest ion ions tpr o ov enides su recarr conier cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . sen se an d collision det ect ion. Full- du plex operat ion cannot be su ppor t ed on Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy 10 0Base- T4 . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figu r e 8 - 1 8 . Th e 1 0 0 Ba se - T4 W i r e- Pa ir U sa ge Du r in g Fr a m e Tr an sm issi on

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise eran v iew s of t echn ologsch ies em essen t o n et wor 8k ing ofession all ped lev els, 10 0BaseT4 uov ses 8B6 T encoding e int ial w hich each b it pr binar y b ytals e isatmap in t of rom a nov ice t o ex pert . pat t er n of six t er nar y ( t h r ee- level: + 1, 0, – 1) sy m bols k now n as 6T code- gr oups. Separ at e 6 T code- gr oup s are used f or I DLE and f or t he con t rol cod e- gr oups t hat ar e n ecessar y f or fr am e New chapt er s include of im por t opics and EAP t r ansm ission. I DLE receiv edcov onerag t h e ededicat ed trant eceiv e pairlike indVoI icatPes t h at t h e link is qu iet . Cov erag et ran of cut t ing edge echn ologies lik e opt n et wor ingin and st or agerou nd- r ob in Du ring f r ame sm ission , 6T tdat a cod e- g r oups ar eical t r ansm it t ked a delayed seq uence ov er t he t h ree t r ansm it w ir e– pair s, as show n in Figur e 8- 1 9. Each f ram e is Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . encapsulat ed wit h st ar t - of- st r eam and end - of- pack et 6T code- gr oups t hat m ark b ot h t he beginn ing and end of t he f ram e, an d t h e beginn ing and end of t he 6 T code- gr oup st r eam on I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat each w ir e pair . Receip t of a non- I DLE cod e- g rou p ov er t h e dedicat ed r eceiv e- p air any t im e enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing befor e t he collision win dow ex pir es in dicat es t hat a collision has occur red. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Figu r eessionals, 8 - 1 9 . Th e 1dless 0 0 Ba - T4ise. Fr a m e Tr a n sm i ssion Sequ en ce net w or kin g p rof r egar of se ex pert Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

100Base-T2 The 1 00Base- T2 sp ecificat ion w as dev eloped as a bet t er alt er nat iv e f or up gr ading net w or ks wit h inst alled Cat eg ory 3 cabling t h an w as b ein g p rov ided by 1 00Base- T4. Tw o im p ort an t n ew goals •w ere d ef ined:Table of Content s •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

To p r ovide com m un icat ion ov er t wo pair s of Cat egor y 3 or b et t er cab le

By Cisco Systems, Inc.

To su ppor t bot h half- d uplex and f ull- dup lex op er at ion Pub lish er: Cisco Press

10 0Baseu ses a diff ent sig nal t r ansm ission pr oced ur e t han an y pr ev ious t wist ed- p air Pub Dat T2 e: Sep tem ber 1 1, er 2 003 Et h er n Iet imp lem ent at ions. I n st ead of using t w o sim plex lin ks t o f orm one f ull- dup lex link , t h e SBN: 1- 58 705 -1 19 -2 10 0Base- T2 d ual- dup lex b aseban d t ran sm ission m et hod sen ds encoded sy m bols sim ult aneously Pages: 11 28 in bot h dir ect ions on b ot h w ir e p airs, as sh own in Figur e 8- 2 0. Th e t erm " TDX< 3: 2> " indicat es t he 2 m ost sign ificant bit s in t he n ib ble bef ore encodin g an d t ran sm ission . " RD X< 3 : 2> " in dicat es t he sam e 2 bit s aft er r eceipt and decoding.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ingedgreet ech Figu 8 - nologies. 2 0 . Th e 1 0 0 Ba se - T2 Lin k Topology Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Du al- d uplex baseband t r ansm ission r eq uir es t he NI Cs at each end of t he link t o be operat ed in a m ast er / slave loop - t im in g mod e. Which NI C w ill be m ast er and w hich w ill b e slav e is d et er m in ed by au t onegot iat ion du rin g link in it iat ion . When t he lin k is operat ion al, syn ch ron izat ion is b ased

on t he m ast er NI C's in t ern al t r ansm it clock . Th e slav e NI C uses t he r ecov er ed clock f or bot h t r ansm it and r eceiv e oper at ions, as show n in Figur e 8- 2 1. Each t r ansm it t ed f r ame is encapsulat ed, an d link sy nchr onizat ion is m aint ained w it h a cont inu ous st r eam of I D LE sym bols du rin g in t er f ram e g aps.

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Figu 8 - 2 1 .s Th e 1 0 0 Ba se - T2 Loop Tim i ng Con f igu r at ion Tabler e of Content I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age The 1 00Base- T2 en cod ing pr ocess f ir st scr amb les t he dat a f ram e n ib bles t o r and om ize t he b it Aut h ored w or ldw leader w or or each t he I nn ib t erble n etint . o t w o f iveseq uence. I t t h by en Cisco m aps Sy t h esttems, w o u pper b itide s and t he tin wonet low er king bit s fof level ( + 2, + 1, 0 , –1, –2) pu lse am plit u de- mod ulat ed ( PAM5) sy m bols t h at ar e sim ult aneously It rnansm t ern etitwt ed or kov in er g Tech , Four Eder it ion is aam com pr ehensive t hat t he tnologies wo w ire Hand pair sbook ( PAM5x 5) .t hDiff ent, scr bling pr oced ur refer es forence m ast er and enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ing slave t ran sm ission s en su r e t hat t he d at a st r eams t rav elin g in op posit e dir ect ions on t h e ork same twechnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing ire pair ar e un coor din at ed . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h an d u pdat secur , st or ission. age, opt ical net w in g, Signal r ecept ionnew is essent ially ed t hechapt r evererses on of sig nal itt yr ansm Because t hor e ksig nalscalabilit on eachy,w ir e and speed, t h is is book a com an d uitpt o-signal d at e r ef er ence o t heedt op ics t hat are receiv essener t ial t o all pair at t he MDI t h e issum of tplet h e ter ansm t ed and t he r teceiv signal, each net wror kin essionals, r egar dless of ex subt act s tgh pe rof t r ansm it t ed sy mb ols fr om t h pert e sigise. nal r eceiv ed at t he MDI t o recov er t he sym b ols in t he in com ing d at a st r eam . The incom ing sy m bol p air is t hen decoded, un scr am bled, an d Reader a ga reat and WAN n et w or k ing, p ar t icu lar ly t h e r econstsit uwtill edobt as ain a dat nibberleun forder t r st anan sf ding er t o of t h eLAN MAC. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . 1000 Cov eragMbps—Gigabit e is also ext end ed n Ethernet ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals The Gigabit Etoper her net at e.stTools an darand ds d gu ev elop id elines m enftorr esu optltim edizing in t wsyst o prem im ar per y for specif m ance icat ions: w ill incr 100ease 0Base- T pr odu for UTP ct iv copper it y an dcable im prand ov e 1eff 000 iciency, Base- X help STP ingcopper t he r eader cable,mas ake w ell moras e single in t elligent an d, mcost u lt im - effode icient opt ical decisions fib er ( see for Figur t h eir e 8-net 2 2)w. ork s.

Figu r e 8 - 2 2 . Gi gab it Et h er n et Va r ia t i ons

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

1000Base-T Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom 10 00Base- T Et hern et pr ov ides fu ll- d uplex t r ansm ission over f our - pair Cat eg ory 5 or bet t er UTP nov ice t o ex pert . cable. 100 0Base- T is based lar g ely on t he find in gs an d d esign app roaches t h at led t o t h e dev elop ment of er t he Fast Et her sical layter p lem ent ions: New chapt s include covnet eragp ehyof im por antimt opics likeatVoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age 10 0Base- TX pr ov ed t h at bin ary sy m bol st r eams cou ld b e successf ully t r ansm it t ed ov er Cat y 5byUTP cable 125 wMBd . ide leader in net w or king f or t he I n t er n et . Aut egor h ored Cisco Sy statems, or ldw p rovnologies ided a basic der,stFour an ding ofit tion he , pr ed t o sen ding m tult ilev el I n t ern10 et 0Basew or k in T4 g Tech Handun book t h Ed isoblem a comsprr elat ehensive refer ence hat signals ov er fou r w ire pairs. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing 10 0Base- T2 p rov ed t hat PAM5 encodin g, coup led w it h digit al sign al pr ocessing, cou ld indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . han dle bot h sim ult aneous t w o- w ay d at a st r eams and pot ent ial cr osst alk pr oblem s r esult ing Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, fr om alien sig nals on adj acent w ire p airs. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. 10 00Base- T scram b les each b yt e in t h e MAC fr am e t o ran dom ize t he bit sequence b ef ore it is encoded usin g a 4- D , 8- St at e Trellis Forw ar d Er r or Cor r ect ion ( FEC) cod ing in w h ich fou r PAM5 Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e sym b ols are sent at t he sam e t ime over f our w ir e pair s. Fou r of t he fiv e lev els in each PAM5 har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on sym b ol r ep resen t 2 bit s in t h e dat a by t e. The f ift h level is u sed for FEC codin g, w hich en hances a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions sym b ol r ecov er y in t he pr esence of noise and crosst alk . Sep ar at e scr am blers for t h e m ast er and t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . slave PHYs cr eat e essent ially un cor r elat ed dat a st ream s bet w een t h e t w o op posit e- t rav elling Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy sym b ol st ream s on each w ir e pair . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease The10 00Base- T link t op ology is show n in Figur e 8- 2 3. Th e t erm " TDX< 7: 6> " indicat es t he 2 pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient m ost signif ican t bit s in t h e dat a by t e bef ore encodin g an d t ran sm ission . " RD X< 7 : 6> " in dicat es decisions for t h eir net w ork s. t he sam e 2 bit s aft er r eceipt and decoding.

Figu r e 8 - 2 3 . Th e 1 0 0 0 Base -T Lin k Topology

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv itr yecov an derim pr ov e ast eff iciency, t hegr eader m res ake ar mor e in t elligent , cost icient The clock y an dm er / slav ehelp looping t imin p rocedu e essent ially t he sam- eff e as t hose decisions for t h eir net w ork s. used in 10 0Base- T2 ( see Figur e 8- 2 4) . Wh ich NI C will b e m ast er ( t yp ically t h e NI C in a m ult ip ort int er m ed iat e net w ork node) an d wh ich w ill be slav e is det erm ined du ring au t onegot iat ion.

Figu r e 8 - 2 4 . 1 0 0 0 Ba se- T M a st er / Sla ve Loop Tim i ng Con fi gu r at i on

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Each Cov t r ansm ram e isedge encapsulat ed w it hlik stearopt t - ofical - st ream ank ing d enand d- of-ststorr eam eragitet ed of fcut t ing t echn ologies n et wor age delim it er s, and loop t imin g is m aint ain ed by con t inuou s st ream s of I DLE sy mb ols sent on each w ir e pair du rin g int er frAut amheored gap s. by 100 Cisco 0BaseSy stTems, su ppor w ort sldw bot ide h halfleader d uplex in netand w orfking ull- dup f orlex t heopI nert er atnion. et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing 1000Base-X t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . All t hplet reee10 X vdersions su chapt ppor t er fulldu secur plex binar ansmopt ission Mb ov er t wy, o Com w 00Baseit h new an u pdat ed s on it y , styort rage, ical at net1w250 or k in g,ps scalabilit st r ands of op t ical fiber or t w o STP copp er w ir e–p air s, as show n in Figur e 82 5. Tr ansm ission and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all coding is based on t h e ANSI Fibrdless e Chan 8B/ise. 1 0B encod in g schem e. Each 8- bit dat a by t e is net w or kin g p rof essionals, r egar of nel ex pert m apped int o a 10 - bit cod e- g r oup for b it - ser ial t r ansm ission. Like ear lier Et her net v ersions, each dat a fr am encapsulat ederatun t hder e ph b ef ore r ansmission Reader s weillisobt ain a g reat stysical an dinglayer of LAN and tWAN n et w or,k and ing, link p ar t sy icunchr lar lyonizat t h e ion is m aint sending a con s st ream of ndam I DLE ent codal e- tgech rounology ps d ur in g or inmat t erfion r ame gaps. All on har dwained ar e, prby ot ocols, and ser tvinuou ices inv olv ed . Fu inf is pr ov ided 10b00BaseX ph ysical layalersy s st sup t b otserv h halfd uplex ll-ailed dup lex op er ion. a r oad r ang e of int egr empor s and ices, in cludand ing fu det descr iptat ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Figu r e 8and - 2 5gu. id1elines 0 0 0 Ba X izing Lin ksyst Con igufor r at ion w ill incr ease pr of essionals oper at e. Tools f or seopt im em fper m ance pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The p r in cip al dif ferences am ong t he 100 0Base- X ver sion s ar e t he link media and connect or s t hat t he par t icu lar ver sion s w ill supp ort and , in t he case of opt ical m ed ia, t he w av elen gt h of t he opt sign ( see Table 8 - 3) . - selling all- in- one net w ork ing r ef erence p rov ides cover age of Theical u pdat edaledit ion of t he b est essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom le. 8 -3 . 1 0 0 0 Ba se - X Li nk Con fi gu r at i on Su ppor t nov ice t o Tab ex pert New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP 1 0 0 0 Ba se - S X ( 8 5 0 1 0 0 0 Ba se - LX ( 1 3 0 0 Li nkCov Conf ig ura 1 0 0 0tBa seologies - CX W a vn el h) and stnm W a v el en gt h) erag e oft ion cut t ing edge echn lik e nm opt ical et en worgtk ing or age 15 0 W

STP copper Sup por t ed Not su ppor t ed Not su ppor t ed Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . 12 5/ 62 .5 m m Not su ppor t ed Sup por t ed Sup por t ed I nmt ern et w or kop in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat ult im ode t ical enables fib er [ 1] net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing 12 5/st50 mn ulthow im ode Not Sup t edolog ies in t o a LAN/ SupWAN por t ed indu ry .m m Lear t o incor porsuatppor e intt ed er net w or kin g por t echn env ir onm ent . opt ical f iber Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all 12 5/ 10 m m single m od e Not su ppor t ed Not su ppor t ed Sup por t ed net w or kin g p rof essionals, r egar dless of ex pert ise. opt ical f iber Reader s wconnect ill obt ain WAN n etplex w or k ing,SFF p arMTt icuRJ lar or ly tDu h eplex Allow ed or sa g reatI er ECun st der yle st 1 an or ding Fibr eof LAN SFF and MT- RJ or Du har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Ch annel st y le 2 SC SC a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy [ 1] The 125/ 62.5 m m specification r efer s to the cladding and cor e diameter s of the optical fiber . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Network Crossover Requirements decisions forCabling—Link t h eir net w ork s. Lin k com p at ib ilit y requ ires t h at t h e t r ansm it t er s at each end of t he link be connect ed t o t he r eceiver s at t he ot h er en d of t h e link . How ev er, becau se cab le con nect ors at bot h end s of t he link ar e k ey ed t he sam e, t he condu ct ors mu st cr oss ov er at som e p oin t t o ensur e t hat t r ansm it t er out p ut s ar e alw ay s connect ed t o r eceiver inp ut s.

Unfor t u nat ely, wh en t h is requ irem ent f ir st came up in t h e dev elopm ent of 10Base- T, I EEE 8 02. 3 chose not t o m ak e a har d r u le as t o w h et h er t he cr ossov er sh ould be im plement ed in t he cable as show n in Figur e 8- 2 6a or w het her it shou ld b e im plem ent ed int ern ally as show n in Figur e 826 b.

• •

Figu r e 8Table - 2 6of. Content Alt e rsn at i ve W a ys for I m pl em e nt in g t he Li nk Cr ossov er I ndex Re qu ir e m en t

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Iand nst ead, I EEE 8 02. 3 defin o ru e tewroefrer ecom speed, t h is book is a ed comt w plet e les an dan ud p-m t o-ad d at encemtendat o t he ion t ops:ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Ther ustain b e aan oddernum b er stofancrding ossov all mWAN u lt icond linkps.ar t icu lar ly t h e Reader s weillmobt g reat un der ofers LANin and n et wuct or or k ing, har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on I f a PMD is equip ped w it h an int er nal cr ossov er, it s MDI m u st be clearly labeled w it h t h e a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions gr aph ical X sym b ol. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy I m plem ent at ion of an int er nal cr ossov er fu nct ion is op t ional. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. andt ogu elines im systpem forr ecom m ance w ill incrt hat easet he When a D TE is conTools nect ed a id r ep eat erf or or opt sw it chizing ( DCE) ort , per it is m ended pr oducrossov ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient er be im plem ent ed w it hin t he D CE por t . decisions for t h eir net w ork s. The ev ent ual result was t hat por t s in most DCEs w er e equ ip ped wit h PMD s t hat cont ained int er nal cr ossov er cir cuit r y and t h at D TEs had PMD s w it hout int er nal cr ossov ers. Th is led t o t he follow ing oft - quot ed de f act o " inst allat ion r u le" :

Use a st r aig ht - t h rou gh cable w hen con nect in g D TE t o DCE. Use a cr ossov er cab le w hen connect ing DTE t o D TE or DCE t o DCE. Unfor t u nat ely, t he de fact o r ule d oes not apply t o all Et h er n et ver sion s t hat hav e b een developed subsequent t o 10Base- T. As t h in gs n ow st and, t he f ollow ing is t r u e: All f ib er - b ased syst em s use cables t hat hav e t he cr ossov er im plem ent ed w it hin t he cable. •

Table of Content s

I ndex syst em s using t w ist ed - pair link s use t h e sam e r ules and r ecom m endat ion s as All 10 0Base I nt e rn 10 et wBaseor k ingT.Te chnologie s H a ndbook , Four th Edit ion •

By Cisco Systems, Inc.

10 00Base- T NI Cs m ay im plem en t a select ab le int ern al cr ossov er opt ion t hat can b e negot iat ed and enabled dur ing aut on eg ot iat ion. Wh en t h e select able crossover op t ion is not Pub lish er: Cisco Press im plem ent ed, 10Base- T r ules and r ecom m endat ion s apply . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

System Considerations Giv en all t he choices d iscussed p rev iously , it m ight seem t h at it wou ld b e no pr oblem t o upgr ad e an ex ist ing net w or k or t o plan a new n et w or k . The pr oblem is t w ofold. Not all t he choices ar e r easonab le for all net w ork s, and n ot all Et her net v er sions an d op t ions ar e av ailable in t he •m ar ket , ev enTable of Content t h ough t hey sm ay h ave b een specif ied in t he st and ard . •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Choosing UTP-Based Components and Media Category By Cisco Systems, Inc.

Pub lish Cisco Press By now , er: it should be obv iou s t hat UTP- based NI Cs ar e av ailable for 10- Mbps, 10 0- Mb ps, and Pub Dat e: Sep beren 1 1, 2 003 10 00- Mbps im tem plem t at ions. The ch oice is r elat ively simp le for b ot h 10- Mbps an d 1 000 - Mbp s I SBN: 158 705 -1 19 -2 oper at ion: 10Base- T and 1 000 Base- T. Fr om t he pr ev ious d iscussions, how ever , it w ould n ot seem Pages: t o be 11 t hat 28 sim ple f or 10 0- Mbp s im plem ent at ion s.

Alt hou gh t hr ee UTP- b ased NI Cs ar e defin ed f or 100 Mb ps, t h e m ark et h as ef fect ively nar r ow ed t he ch oice t o ju st 10 0Base- TX, w hich b ecam e w idely available d ur ing t he f irst half of 199 5: The uBy pdat t he T4 b est one orkting r efarerence p rov idesTXcover t hed e t edit ime ion 100of Basepr- selling odu ct s allfir stinapp earnet edwon he m ket , 1 00Basew asage w ellof essentent ialr enched, an d cu t t ingedg e t ech nologies. an d d ev elopm en t of t h e fu ll- d uplex opt ion , w hich 1 00Base- T4 cou ld n ot supp ort , w as w ell und er w ay . Con ov er v T2 iewst s andar of t echn ies essen t ial n et k ing19pr97, ofession allerlev The cise 1 00Based wolog as not appr ov ed t o u nt il wor spr ing t oo latals e t at o int estels, t hef rom nov ice t o ex pert . m ar ket place. As a result , 1 00Base- T2 p r oduct s w er e not ev en m an ufact u red. chapt er s include cov erag e of imf or porUTP t antmt opics VoI P and SeverNew al choices hav e also been specified edia: like Cat eg ory 3, 4 EAP , 5, or 5E. The dif fer en ces ar e cable cost and t r ansm ission r at e capabilit y, bot h of w hich in cr ease w it h t h e cat eg or y Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age nu mb er s. How ever , cur r en t t r ansm ission r at e r eq uir em ent s an d cab le cost sh ould not be t he deciding fact or s in ch oosin g w h ich cable cat egor y t o in st all. To allow for fut ur e t r ansm ission r at e Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . needs, cables lower t han Cat egor y 5 sh ould not ev en be considered, and if gigabit r at es are a possible Cat eg or yHand 5E should be seriou consider ed :pr ehensive refer ence t hat I n t ern et wfuort ur k ine gneed, Tech nologies book , Four t h Edsly it ion , is a com enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing I nst allat ion lab or cost s are essen t ially const an t f or all t y pes of UTP f our - pair cable. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet it h new d u adin pdatgedinchapt er scab onlesecur y ,instgort he age, icaland net w or kalling in g, scalabilit Labeorw cost s foran u pgr st alled ( remitov exopt ist ing inst new ) ar ey, and speed, t h is book is a com plet e an d u pt od at e r ef er ence t o t he t op ics t hat are essen t ial t o all t y pically gr eat er t h an t he cost of t h e or ig inal inst allat ion. net w or kin g p rof essionals, r egar dless of ex pert ise. UTP cable is back w ar d- comp at ible. Higher - cat eg ory cab le will sup por t low er - cat eg ory NI Cs, Reader g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e bust wn ill ot obt v iceain vera sa. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad of int sy stcab em le s and serv ices, inuch clud lon ingger det tailed ipt ion s,life revofiew Ther ang p hyesical lifegr e ofalUTP ( decades) is m han tdescr h e useable t h equest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . connect ed equ ipm en t . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Auto-negotiation—An Optional Method for Automatically pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligentConfiguring , cost - eff icient decisions for t h eir net w ork s. Link Operational Modes The p ur pose of aut on eg ot iat ion is t o f in d a w ay f or t w o NI Cs t hat sh are a UTP link t o com mu nicat e w it h each ot her , r eg ard less of w het her t h ey bot h imp lem ent ed t he sam e Et h er net v er sion or opt ion set .

Aut on eg ot iat ion is p er f orm ed t ot ally w it hin t he p hy sical lay er s d ur ing lin k init iat ion, w it h out an y add it ion al ov er h ead eit her t o t he MAC or t o high er pr ot ocol layer s. Aut onegot iat ion allow s UTPbased NI Cs t o d o t h e follow ing: Adv ert ise t h eir Et her net v ersion and any op t ional capab ilit ies t o t he NI C at t h e ot her end of t he lin k •

Ackn owTable ledg eofr Content eceipt san d und er st andin g of t he oper at ional m odes t h at b ot h NI Cs shar e

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I ndex

I nt e rn Reject et w or k ing chnologie s H a ndbook an Te y oper at ional m odes, Four t h attharEdit e nion ot

shar ed

By Cisco Systems, Inc.

Con figu re each NI C f or high est - level op er at ional m ode t h at bot h NI Cs can supp ort

lishot er:iat Cisco Aut Pub on eg ion Press is sp ecified as an opt ion for 1 0Base- T, 100 Base- TX, an d 1 00Base- T4, b ut it is Pubed Datfe: ber 1 1,T2 2 003 r eq uir orSep 10tem 0Baseand 1 000Base- T im plem en t at ions. Table 8 - 4 list s t h e defined select ion pr ior it yI SBN: lev els 1- 58( 705 high -1 19 est-2 lev el = t op pr ior it y) for UTP- b ased Et h er net NI Cs. Pages: 11 28

Tab le 8 -4 . The D ef i ne d Aut one got ia t i on Se le ct i on Lev e ls f or UTP N I Cs The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent Se le ct ialion an Le d cu v el t t ingOpe edg r at e itona ech nologies. l Mode Ma x im um Tot al D a t a Tra nsfe r Ra t e ( Mb ps) [ 1 ] 9

5

10 00Base- T f ull- dup lex 20 00 Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom 10 00Base- T h alf - du plex 10 00 nov ice t o ex pert . 10 0Base- T2 f ull- dup lex 20 0 New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP 10 0Base- TX fu ll- d uplex 20 0 Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age 10 0Base- T2 h alf - du plex 10 0

4

Aut h ored by Cisco Sy st ems, w or ldw ide leader 10 0BaseT4 h alf - du plex 10 0 in net w or king f or t he I n t er n et .

8 7 6

I n3 t ern et w or k in g Tech Hand book Four10 t h0Ed it ion , is a com pr ehensive refer ence t hat 10nologies 0Base- TX halfdup,lex enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing 2 10t Basedu cep plext s, t echn 20 ologies, an d devices used in t oday ' s net w ork ing t echnologies. Mast er he t erTmfulls, con indu incorTpor at ed uplex int er net w or 1 st ry . Lear n how10t oBasehalf10kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. [ 1]

Because full- duplex oper ation allow s sim ult aneous tw o-w ay tr ansm ission, the m axim um total t ransfer r ate for full- duplex oper ation is double the half- duplex transmission r ate.

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har e, pr otiat ocols, ser vinices invbased olv ed .NI FuCs ndam t ech nology inf orTmat Thedw auar t onegot ion fuand nct ion UTPusesent a al m odified 10Baselinkion in tis egpr ritov y ided pulseon a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions seq uence in wh ich t h e NLPs ar e r eplaced by b ur st s of fast lin k pulses ( FLPs) , as show n in Figur e t8o 2en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . 7. Each FLP bur st is an alt er nat ing clock / dat a seq uence in wh ich t h e dat a bit s in t he b ur st Cov erag is op also ext end ed n ot only t o tnew n et ing concep t s,Cbut , legacy ident if y tehe er at ional m odes su ppor ed by t hwor e t rkansm it t in g NI andalso alsot opold rover ide inf or mat ion syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm in w is hich used by t he aut onegot iat ion han dshak e m echan ism . I f t h e NI C at t he ot h er en d ofent t hes link a pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease com pat ible NI C but does not hav e aut onegot iat ion cap abilit y, a par allel det ect ion f unct ion st ill pr odusctitivtitoybe anrdecog im pr ov e eff ingt ot he r eader ake bur mor , cost - eff icient allow nized. A iciency, NI C t h athelp f ails r esp ond t omFLP stes in ant elligent d r et ur ns only NLPs is decisions for t h eir net w ork s. t r eat ed as a 10Base- T h alf- du plex NI C.

Figu r e 8 - 2 7 . Aut on eg ot ia t i on FLP Bur st s Rep la ce NLPs D ur i ng Li nk I ni t ia t i on

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

At fir st glance, it may appear t h at t h e aut onegot iat ion p rocess wou ld alw ay s select t h e m ode supp ort ed by t he NI C wit h t h e lessor capabilit y , w hich wou ld b e t he case if bot h NI Cs u se t he sam e en cod ing pr ocedu r es an d lin k con figu rat ion . For exam ple, if bot h NI Cs ar e 1 00Base- TX b ut only on e suppor t s full- du plex oper at ion , t h e negot iat ed operat ion al m ode w ill be half- d uplex The0Baseu pdatTX. ed edit iont un ofatt he all-10 inone net ork ing erence idesw cover ageotofher at 10 Un for ely ,b est t h e- selling diff erent 0Base verwsion s ar reefnot com p rov at ible it h each essent ial anan d dcuat t10 ingedg e TX t ech 10 0 Mbps, 0Basefunologies. ll- d uplex NI C w ou ld au t onegot iat e w it h a 1 00Base- T4 NI C t o oper at e in 10Base- T h alf - du plex mod e. ov er iew00Bases of t echn olog essen o nt onegot et wor kiat ingion pr in ofession als at sy allstlev els,ex f rom Aut onCon eg otcise iat ion inv 10 X NI Cs ies is sim ilart ial t o tau UTP- based ems, cept nov ice t o ex pert . t hat it cu rr ent ly app lies on ly t o com pat ible 1 000 Base- X devices and is cur rent ly con st r ained t o negot iat e only half - dup lex or f ull- du plex operat ion an d f low cont r ol d ir ect ion. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Network Switches Provide a Second, and Often Better, Alternative to Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Higher Link Speeds in CSMA/CD Network Upgrades I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Com pet itnet iv ely riced et wor k sw it tches on ten het mar et por shor af er t ernet t he m idenables w orpkin g pnr ofessionals o un became derst andavailable an d im plem contkem art yly int w ork ing 19 90s an d essen t ially mad e net w or k repeat er s obsolet e for lar ge net w ork s. Alt hou gh repeat s t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w orker ing can accept only one f r ame at a t ime and t hen send it t o all act iv e por t s ( ex cept t he por t on w hich indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . it is bplet eineg w r eceiv ed ) ,answ es ed arechapt eq uipped it h t he ing : opt ical net w or k in g, scalabilit y, Com it h new d ituch pdat er s onwsecur it yf,ollow st or age, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. MAC- based por t s w it h I / O fr am e buf fer s t h at eff ect iv ely isolat e t h e por t f r om t r aff ic being sen t at t he ain samaegtreat im eert oun order fr om her por t s onand t heWAN sw it ch Reader sw ill obt st anotding of LAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Mu lt ip leeinoft ern h sst hat sev eral fr am t oailed b e t rdescr ansfeript red w een fer enions t a b r oad r ang intal egrdat al asypat st em and allow serv ices, in clud ingesdet ionbet s, rev iewdif quest por t s at t he sam e t im e t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy These m ay seem lik e sm all d iff er ences, b ut t hey pr odu ce a m ajor ef fect in net w or k operat ion . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Becau se each por t p r ovides access t o a h igh- speed n et wor k b rid ge ( t h e sw it ch) , t he collision pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease dom ain in t he net w or k is r ed uced t o a series of sm all dom ains in w hich t he nu m ber of pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient par t icipant s is redu ced t o t wo—t he sw it ch p ort and t h e con nect ed NI C ( see Figur e 8- 2 8) . decisions for t h eir net w ork s. Fur t her mor e, because each p art icipan t is now in a pr iv at e collision d om ain , his or her av ailab le ban dw idt h has n ot on ly been m ar kedly in cr eased, it w as also d one w it hou t hav ing t o ch ange t he link speed.

Figu r e 8 - 2 8 . Repl acin g t he N et w or k Rep ea t e r s w i t h Sw i t ch e s Re duces t h e Col li si on D om ai ns t o Tw o NI Cs Ea ch

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Con sider , f or exam ple, a 48- st at ion w or kg rou p wit h a cou ple of lar ge f ile ser ver s and sev eral Reader st an CD dingnet ofwLAN n et wavailable or k ing, pbarandw t icu lar e net w or ks w prill intobt er sain on aa g1reat 00- er Mbun ps der CSMA/ or k. and Th e WAN av er age idtly h ,t h not har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov count in g in t er f ram e g aps an d collision r ecov er y , w ould be 1 00 ÷ 5 0 = 2 Mbps ( net w ork ided pr int on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ser v ers d o n ot g en er at e n et w or k t r af fic) . On t he ot her han d, if t he sam e w or k gr oup w er e st illions on tao1en su re T con cept r ehich en sion r et t ion,been and ad dit ionalwritesou r ces fuitrtch her 0Basenet w orcomp k in wh t h e r and ep eat eren s had replaced h net w orfkorsw es,stt hudy e . Cov ext ed n ot only t o ld new et wor ing concep t s, but also t o old er , legacy ban erag dw idtehisavalso ailab le end t o each u ser w ou b e n10 Mbpks. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e.igur Tools and f or as optr aw im izing syst em per for m ance w ill incr ease Clear ly , n et w or k conf at ion is gu as id imelines por t ant link speed. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

NO TE To ensu re t hat each en d st at ion w ill be capab le of com m un icat in g at fu ll r at e, t he

net w or k sw it ch es shou ld b e non sat u rat in g ( be capable of accept ing and t r ansfer r in g dat a at t he f ull r at e f rom each por t sim ult aneously ) .

Multispeed NICs •

Table of Content s

Aut o- n eg ot iat ion opened t h e door t o t h e developm ent of low - cost , m ult ispeed NI Cs t hat , f or • exam ple, supI ndex por t b ot h half- and fu ll- d uplex oper at ion und er eit her 1 00Base- TX or 1 0Base- T I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion signaling pr oced ur es. Mult ispeed NI Cs allow st aged net w or k upg r ades in w h ich t he 10Base- T By Cisco half - dupSystems, lex end Inc. st at ions can be con nect ed t o 1 00Base- TX f ull- dup lex sw it ch por t s w it hout r eq uir ing t he NI C in t h e PC t o b e ch anged. Then, as mor e b andw idt h is n eeded for in divid ual PCs,Pub t hlish e er: NI Cs inPress t hose PCs can be u pgr ad ed t o 100 Base- TX f ull- du plex mod e. Cisco Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Choosing 1000Base-X Components and Media Pages: 11 28 Alt hou gh Table 8 - 3 sh ows t hat t her e is con sid er able f lex ibilit y of choice in t he 10 00Base- X link m ed ia, t her e is not t ot al f lex ibilit y . Som e choices ar e p refer r ed ov er ot her s: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of NI Cs at bot h ends of t he link m ust be t h e sam e 1 000 Base- X ver sion ( CX, LX, or SX) , and essent ial an d cu t t ing- edg e t ech nologies. t he lin k con nect ors mu st m at ch t he NI C con nect or s. The 1 000ov BaseCXs specif icatolog ion ies allow s eitthial er t st 1 ork ing st y lepr2ofession con nectals or s, st yels, le 2 f is Con cise er v iew of t echn essen o ynle et wor at bu allt lev rom pr efer red because some st y le 1 connect ors are not su it able for operat ion at 125 0 Mbps. nov ice t o ex pert . 10 00Base- CX link s ar e int en ded f or pat ch - cor d use w it hin a com m unicat ions closet and ar e limit t o 25 er s. cov erag e of im por t ant t opics like VoI P and EAP New ed chapt er smet include The 1 000eBaseand 10 00BaseSX specificat her and t he st sm f orm fact or SFF Cov erag of cutLX t ing edge t echn ologies lik e options ical nallow et woreit k ing orall age MT- RJ or t h e lar ger dup lex SC conn ect or s. Because SFF MT- RJ conn ect or s ar e only ab out half lar by ge Cisco as dupSy lex SC connect oride s, and becau se w spor ace is faorprtem , n it et f ollow s t hat SFF Aut has ored st ems, w or ldw leader in net king he iu I nm t er . MT- RJ connect or s m ay become t he p redom inan t conn ect or . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat 10 00BaseLXgt ran sceiver s gener ally cost mor h an 100en 0Baset r ansceiv enables net w or kin p r ofessionals t o un derst and aned tim plem t contSX em por ar y interers.net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing m ax n imhow um op at ing op twical fiber depend oninbot he t ran smenv ission indu stThe ry . Lear t o er incor porr ange at e intfor er net or kin g tsechn ologsies t o ha tLAN/ WAN ir onm ent . w av elengt h an d t he m odal b andw idt h ( MHz.k m ) r at in g of t h e fib er . See Table 8 - 5. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Tab lepr8ot-5ocols, . M aand xi mser um O pe r a tedin. g Ra nge on O pt i ca har dw ar e, v ices inv olv Fu ndam ents al ftor ech Com nologyminf or mat ion is lprFi ovber ideds on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Fibe r Cor e D ia m et e r / M oda l Ba ndw id t h

1 0 0 0 Ba se - S X ( 8 5 0 n m W av e le ngt h )

1 0 0 0 Ba se - LX ( 1 3 0 0 nm W av e le ngt h )

62 .5 m m m ult im ode f iber ( 20 0/ 50 0) MHz. km

27 5 m et ers

55 0 m et ers [ 1]

50 m m m ult im ode f iber ( 40 0/ 40 0) MHz. km

50 0 m et ers

55 0 m et ers [ 1 ]

Table of Content s ode f iber • 50 m m m ult im I ndex

55 0 m et ers

55 0 m et ers [ 1 ]

( 50 0/et50 0)k ing MHz. km I nt e rn w or Te chnologie s H a ndbook ,

Four th Edit ion

By Systems,mInc. 10Cisco m m singleode

Not su ppor t ed

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f iber

50 00 m et er s

Pub lish er: Cisco Press [ 1]Dat Pub 1000Basee: Sep temLX bertr1ansceiv 1, 2 003er s m ay also r equir e use of an offset -launch, m ode-condit ioning patch cor d wh en

cou pling1-to existing multim ode fiber s. I SBN: 58 some 705 -1 19 -2

The opPages: er at in11g28r ang es sh ow n in Table 8 - 5 ar e t hose sp ecified in t he I EEE 8 02. 3 st andar d. I n pr act ice, h ow ev er, t he m ax imu m oper at ing r ange f or LX t r ansceiv er s ov er 62 .5 m m m ult im ode fib er is appr ox imat ely 70 0 met er s, and som e LX t r ansceiv ers hav e been q ualified t o supp ort a 10 ,0 00- m et er oper at ing r ange ov er single- m ode f ib er . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Multiple-Rate Ethernet Networks

Giv enCon t h ecise oppor t u vnit iess sh n b olog y t heies exessen am plet ial in ttohen et p rev s sect ions, it als is not surlev pr ising t h at ov er iew of ow t echn woriou k ing pr ofession at all els, f rom m ost nov lar ge et net iceEtt ohern ex pert . w or ks are now im plem en t ed w it h a m ix of t r ansm ission rat es an d lin k m ed ia, as show n in t he cable m odel in Figur e 8- 2 9. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Figu r e 8 - 2 9 . An Ex a m ple M u lt ir a t e Ne t w or k Topolog y—t h e I SO / I EC Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . 1 1 8 0 1 Cabl e M odel I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing [ View full size im age] t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu IstSO/ ry . ILear how t o incor porelatise tint g t echn iest in a LAN/ WAN env ir onm The EC 1n180 1 cable m od heernnet et wworork kin m odel on olog w hich het oI EEE 8 02. 3 st andar d s arent e . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, based: and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Cam pu s dist r ibu t or— The t er m cam pus r efer s t o a f acilit y w it h t w o or m or e b uildings in a Reader r elat s wivillely obtsm ainalla ar g reat ea. er This unis der t he st an cen ding t r alof point LAN of and t heWAN cam n puetswback or k ing, bone p ar ant icu d t lar he ly t elecom the har dwconnect ar e, pr ot ionocols, pointand wit hser t hveices out side inv olv wed or .ld. FuIndam n Et h er ent net al tLANs, ech nology t he cam inf or pumat s dist ionr ibut is prorovwou idedldon a b r oad t y pically r ang e be of a intgegr igabit al sysw stit em chs wand it h tserv elecom ices,int inerf clud ace ingcapabilit det ailedy .descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Buieldi di ext st r end ib uted or— t he building 's kconn ect ion tpoint t he tcam Cov erag isng also n otThis onlyist o new n et wor ing concep s, butt oalso o oldpus er , backb legacyone. An Ets, h erprnovid et buildin t or icw pict ouldurt ey pically e aw 1 000 ork 1 000 / 10-ent Mbps it ch. syst em in g a gmdorist e rribu ealist of t he b realor ld / n100 et w- or ing en/ 100 vir onm s in sw w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease stdr ib This is t he help flooring 's conn ion point t hee binuilding dist r ib ut or icient . I SO/ I EC pr oduFloor ct iv it ydi an imut pror— ov e eff iciency, t he rect eader m aket omor t elligent , cost - eff 2 11 801 ends decisions forr tecom h eir m net w orkats. least one f loor dist r ib ut or f or ev er y 10 00 m of f loor space in off ice env iron ment s, and, if p ossible, a separ at e d ist r ibut or for each floor in t he building . An Et h er n et floor d ist r ibu t or w ould t y pically b e a 1 000 / 100 / 10- or 10 0/ 10 - Mbp s sw it ch . Te le com out le t — This is t he net w ork con nect ion poin t f or PCs, w or kst at ion s, and pr int ser v ers. File ser v er s ar e t y pically colocat ed wit h an d d irect ly connect ed t o t he cam pu s, bu ild in g, or floor d ist r ibut ors, as appr opr iat e f or t heir int end ed use.

Cam pu s ba ck b one cab lin g— This is t y pically sing le- or m ult im ode cable t h at int er con nect s t he cent r al cam pus dist rib ut or w it h each of t h e building d ist r ibu t ors. Bui ldi ng ba ck bone cab li ng— This is t y pically Cat egor y 5 or bet t er UTP or m ult im ode fiber cable t hat int er connect s t he b uilding dist r ibut or w it h each of t he f loor dist rib ut or s in t he bu ild in g. • •

of Content H ori zonTable t al ca bli ng—s This is pr edom inant ly Cat egor y 5 or bet t er UTP cable, alt hou gh a f ew ndex ar e using m ult im ode f iber. inst allatI ions

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

As w it h Systems, UTP cable By Cisco Inc.select ion, t h e ch oice of link media and int er mediat e n et wor k n odes should alw ays be m ade w it h an ey e t o fu t ur e t r ansm ission rat e need s and t h e lif e exp ect an cy of t h e net w or k elem ent s, un pr ed ict ab le t hou gh t hey m ay be. I n t he 1 990 s, LAN t r an sm ission r at es Pub lish er: Cisco Press incr eased 100 t im es and, by 20 02, will in cr ease yet anot her 1 0 t im es. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN:not 1- 58 -1 19 -2 all—or even som e—end st at ions and t h eir in t er conn ect ing link s w ill This d oes m705 ean t hat r eq uir Pages: e gigab 11 it 28 capabilit y . I t d oes mean, how ever , t hat m or e cent ral net w ork nodes ( such as m ost cam pus d ist r ibu t or s and m any b uilding dist r ib ut or s) shou ld b e eq uipped w it h gigabit capabilit y , and t h at all f loor dist r ib ut or s shou ld hav e at least 100 Mb ps capab ilit y . I t also means t hat all n et w or k sw it ch es sh ould be non blocking an d t h at all por t s should hav e f ull- dup lex capabilit y , and t h at any new camp us b ack bon e link s sh ould be inst alled w it h single- m ode f ib er .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Link Aggregation—Establishing Higher-Speed Network Trunks

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Lin k aggr egat ion is a r ecen t opt ion al MAC capabilit y t h at allow s sev eral phy sical lin ks t o be nov ice t o ex pert . com bined in t o on e logical high er - speed t r un k. I t pr ov ides t he means t o incr ease t h e eff ect iv e dat a rNew at e bet w een w o net wcov orkerag nodes ult tiples t heVoI indPividu link t r ansm ission r at e chapt er s tinclude e ofinimunit por tm ant opicsoflike and alEAP r at her t h an in an or der- of - m agnit u de st ep. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Lin k aggr egat ion can b e a cost - eff ect iv e w ay t o p r ovide higher - speed connect ions in Et h er net LANs Aut t hath ored ar e r by eaching at ion wwit 10ide 0 Mbps t r ansmission r at es t t Ihnat Cisco sat Sy ur st ems, orhldw leader in net w or king f or bu t he t erwnon et .'t requ ire gigab it capab ilit y , at least in t h e shor t t er m . For exam ple, t h e m axim um leng t h for 6 2. 5 m m m imetode lin ks nologies is 200 0 m et ers at 1, 00 Mbp er h as been of t en t used I n ult t ern w orfkiber in g Tech Hand book Four t h s, Ed and it ion mu , is ltaimod comeprfib ehensive refer ence hat f or cam pus b ack bon e link s. The logical up gr ade w ould seem t o be t o r euse t hese lin ks for 1 enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w000 ork ing Mb ps oper at ion, b ut axmimu m supp orttab le len gt h for lt imod eused fiber inis ton ly 700 mwetork er sing t echnologies. Mast er tthe he m t er s, con cep t s, echn ologies, anmu d devices oday ' s net and only w it h 10 00BaseLX. I f t h e ex ist ing lin ks are lon ger t han 70 0 met er s, aggr egat ing n indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . exist ing elink ill suan ppor an ef fect ive ter ran sm ission ( 10 0 opt n) ical Mbps. Com plet w its hwnew d ut pdat ed chapt s on secur itryat , estof or age, net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Lin ionessionals, should ber egar v iewed asofa ex net w ork netkw aggr or kinegat g p rof dless pert ise.con figur at ion opt ion t h at is pr im ar ily u sed in t he few int er connect ions t h at r equir e high er dat a rat es t h an can be pr ovid ed by sing le lin ks, such as sw it ch o- obt sw itain ch aand in er sw it chder - t oserv of er.LAN I t can benused incr ease t he eliabilit Reader s w- till g reat un stfile an ding andalso WAN et w ort o k ing, p ar t icu larrly t h e y of crit Agg regatand ed link can inv b e olv r apidly ( t y pically t 1ion second orided less)onin har ical dw arlink e, s. pr ot ocols, ser vsices ed . Fur econ ndamfigu entred al t ech nology ininfabou or mat is pr ov case of lin k failur it hallow d uplicat ed orinr eor fr ailed am es.descr ipt ion s, rev iew quest ions a b r oad r ang e of e, intw egr sy str isk em sofand serv ices, cluddered ing det t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Lin aggreegat ion ext does eit her t he nI EEE 802 .3 concep dat a f ram f oralso mat (t s) or er any higher lay er s Covkerag is also endnot ed aff n otect only t o new et wor k ing t s, ebut o old , legacy in t he I t or isebrack w aricd-pict com it h " agg ev ices syst emps,rotprocol ovidstinack g a. m ealist urpat e ofible t hewrealw or regat ld n etion w or- unaw k ing ar ene" vir donm ent sanind wcan hichbe used wit h any oper Et her d at a and r at e gu ( alt ough fitordoes not m ake forfor10 Mbp swbecause it w ould pr of essionals atnet e. Tools idhelines opt im izing systsense em per m ance ill incr ease likely cost t oim prpr ocur a pair of 10help 0- Mb NI Cs) . Lin m k ake aggrmor egateion b e ,enabled pr odu ct iv it less y an d ov ee eff iciency, ingpst he r eader in t can elligent cost - effonly icienton par allel point kss.and t hose t hat supp or t f ull- dup lex sam e- sp eed oper at ion. decisions for -t ht oeirpoint net wlin ork

Network Management All hig her- speed Et her net specificat ions includ e definit ion s for m an aged ob ject s and cont r ol

agent s t hat are com pat ib le w it h Sim ple Net w or k Manag em ent Prot ocol ( SNMP) an d t hat can be used t o gat her st at ist ics ab out t he oper at ion of t he net w or k nod es and t o assist in net w ork m anagem ent . Because user infor m at ion is anecdot al at best an d u su ally com es long aft er t he fact , all larg er net w ork s shou ld at least be conf igur ed w it h m anaged sw it ch es an d net w ork ser v ers t o ensur e t hat pot en t ial pr oblem s and bot t lenecks can be id en t ified b ef or e t hey cause ser ious net w ork d et er ior at ion. •

Table of Content s

• Migrating I ndex to Higher-Speed Networks I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

By Cisco now ,Systems, it should By Inc.be appar ent t hat upg rad in g ex ist in g net w ork s t y pically does not r eq uir e w holesale equ ipm en t or media ch anges, bu t it does r eq uir e kn ow ledg e of t he cu rr ent net w ork confPub ig ur and t he n et w or k locat ion of p ot ent ial pr ob lem s. This m eans t h at a net w or k lishat er:ion Cisco Press m anagem ent sy st em sh ould be in place and t hat a cab le plant dat abase shou ld b e bot h av ailab le Pub Dat e: Sep tem ber 1 1, 2 003 and accur at e. I t is t im e- con su m in g an d oft en diff icu lt t o det erm ine link t yp e and av ailab ilit y af t er I SBN: 1- 58 705 -1 19 -2 t he cab les h ave been pu lled t hr oug h cond uit , b ur ied in w alls, an d lay ered in cab le t ray s. Pages: 11 28

Lin ks ar e of t en t he limit in g f act ors in n et w or k u pgr ades. Ex ist in g Cat egor y 5 lin ks sh ould su ppor t all cur r en t Et her net r at es fr om 1 0 Mbps t o 10 00 Mbp s, alt houg h t hey sh ould be t est ed t o ensur e t heir capab ilit y t o supp ort gigab it r at es. I f t he net w or k is equip ped w it h only Cat eg ory 3 cable, som e lin ks will h ave t o b e replaced b ef or e up gr ading t o 1 000 Mb ps. A sim ilar sit u at ion ex ist s w it h usin gleultof imtode iber. Mult im ode iber net canwnot be ur sed for allp backb one instage allatof ions. The pdat ed and editm ion he bfest - selling allin- fone ork ing ef erence rov ides cover Singlem ode f iber, on t he ot h er h and, not only can sup por t all backb one lengt h s up t o 10, 00 0 essent ial an d cu t t ing- edg e t ech nologies. m et er s at 100 0 Mbps, b ut it also w ill be cap able of supp ort in g b ack bon e use at 10- g igabit dat a r at es in t he fu t ur e. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Sw it ch r eplacem nov ice t o exent pertcan . b eg in as soon as t h e necessary link s ar e av ailable. Ex ist in g sw it ches at t he cam pu s and bu ild ing dist rib ut or levels can oft en be r eused at t he b uilding or f loor dist r ib ut or er s includeb ecov erag e oft oim andstEAP level. New NI Cschapt can generally r ep laced expor t ent dant t het opics usefulike l lifeVoI of Pend at ions. And so on . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary The ch apt er began w it h an ov er view of t h e Et her net t echn olog y, t he n et w or k b uilding blocks, and Et hern et ' s r elat ion sh ip t o t he I SO sev en- lay er ref er ence m odel. The r equir ement s for MAC and PHY com pat ib ilit y also w er e int r odu ced. •

Table of Content s

• I ndex The b asic MAC r esponsibilit ies wer e defin ed : I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

D a t a en ca psul at i on— Assemb lin g t he f ram e in t o t h e defined for m at befor e t r ansm ission begins, an d disassemb lin g t he f ram e af t er it h as been r eceiv ed and checked for Pubt rlish er: Cisco Press ansm ission er r or s. Pub Dat e: Sep tem ber 1 1, 2 003

Me di a1-a58 cce cont I SBN: 705ss -1 19 -2 r ol— I n t h e r eq uired CSMA/ CD h alf- du plex m ode, and in t he op t ion al fu lldup lex m ode. Pages: 11 28 Tw o op t ional MAC capab ilit y ex t ension s and t heir associat ed fr am e f orm at s w er e discu ssed. The VLAN t aggin g op t ion allow s n et w or k nod es t o b e defined w it h log ical as w ell as phy sical add resses, an d p rov ides a means t o assig n t ran smission p rior it ies on a fr am e- by - fr am e basis. A specif ic for m at f or t h e pause f r ame, w hich is used f or shor t - t er m link f low cont r ol, is defin ed in The u pdat edd edit t hecover b est -ed selling in- oneit net w ork r efMAC erence p rov ides cover age t he st an dar but ion w asofnot h er e allbecause is aut oming at ic capabilit y t hat is inv okof ed as essent ial an d cu t t ingedg e t ech nologies. needed t o pr ev en t inp ut buf fer ov er r un . The PHY layer d iscussions included descr ipt ion s of t he signaling p rocedur es and m edia cises/ov eritvat iew t echn iesinessen t ial t o n et wor k ing pr ofession als at all lev els, f rom r eq uirCon em ent lim ions soffor t he olog f ollow g: nov ice t o ex pert . New chapt 10 BaseT er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag eTX, of cut t ing edge ologies likT2 e opt ical n et wor k ing and st or age 10 0Base100 BaseT4,t echn and 100 BaseAut h ored by Sy st ems, or ldw ide LX, leader net w or king 10 00BaseT, Cisco 10 00BaseCX, 1w000 Baseand in100 0BaseSX f or t he I n t er n et . I n t hou ern et k in g Tech , Four t h Ed it, ion is at hcom pr ehensive refer Alt ghw or 100 BaseFXnologies w as n ot Hand specifbook ically d iscussed it u, ses e same sig naling prence ocedut hat r e as enables w or kinov g er p r ofessionals derst d im plem en t cont 10 0Base-net TX, but op t ical fibert omun edia r atand h er an t han UTP copper . em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu rstem ry .aining Lear n sect howions t o incor por at e int or kin g t echn iescon in t sid o aerLAN/ WAN ent . The of t he chapt er er w net er ewdev ot ed t o sy olog st ems at ions for env b otirhonm t wist edCom plet w itical h new d u pdat ed chapt on secur it y , st or age, opt ical net w or k in g, scalabilit y, pair an d eopt fiberanLAN im plement ater ions s: and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Lin k cr ossover r equir ement s in UTP n et wor k s Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e chin g ocols, of PMDand s and w orinv k m eded ia. tFu o en su reent desir at a r atinf es or mat ion is pr ov ided on har dwMat ar e, pr ot sernet v ices olv ndam al t ed echdnology a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Use link aggr egat ion o cr eat - speed t r u nkr sesou r ces f or fu rt her st udy . t o en su re of con cept comp r eh entsion ande high r et enert ion, andlogical ad dit ional Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy I ms,plem entin atgion oformeult ispeed net w syst em pr ovid am r ealist ic pict uror e kofs t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Aft er essen t ially f inishing t he ch apt er, you shou ld hav e a r easonab le wor k ing k now led ge of t he pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Et h er n et pr ot ocol and net w or k t echnology . Th e nex t sect ion should help det er m ine w h et h er you decisions for t h eir net w ork s. need t o go back and r eread t he ch apt er.

Review Questions 1:

Shou ld n' t all 1 0Base- T net w or ks just be up gr aded t o 1 00 Mbp s? Why or w hy not ?

2:

I ndex 100 Base ver sion ( s) ar e r ecom m en ded? W hy ? Which

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

: Which By Cisco 3 Systems, Inc.100 0Base 4:

v er sion( s) ar e r ecom m ended? Wher e w ould t hey be u sed?

What cable t y pes should be used f or new net w or k s? For upg rad ing ex ist ing net w or ks? Why ?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I5 SBN: 58 705 -2 : 1How d -1 o 19 y ou

kn ow w hen a net w or k needs t o be u pgr aded? Wher e do you st ar t ?

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 9. Fiber Distributed Data Interface Obj e ct i ve s • •

Table of Content s

Pr ovid e backg r ound inf orm at ion abou t FDDI t echn ology . I ndex

I nt e rn Ex et wplain or k inghow Te chnologie H aks. ndbook , Four th Edit ion FDD I wsor By Cisco Systems, Inc.

Descr ibe t he dif fer en ces b et w een FDD I and Copp er Dist rib ut ed D at a I nt er face ( CDDI ) . Pub lish er: Cisco Press

Descr ibe h ow CD DI w or ks.

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction The Fib er Dist ribu t ed Dat a I n t er f ace ( FDDI ) sp ecifies a 1 00- Mbps t oken- p assing , du al- r ing LAN using fib er - opt ic cab le. FDD I is fr equent ly used as h ig h- speed b ack bon e t ech nology b ecause of it s sup por t f or high b andw idt h and g reat er dist ances t han copp er . I t sh ould be not ed t hat •r elat iv ely recen Table s copper specificat ion, called Cop per Dist r ib ut ed Dat a I n t er f ace t ly,of aContent r elat ed •( CD DI ) , has Iem ndex erg ed t o pr ov id e 10 0- Mbp s ser v ice over copper . CD DI is t h e imp lem ent at ion of IFDDI nt e rn et orocols k ing Teov chnologie H a-ndbook , Four thwEdit pw rot er t w ists ed pair copper ir e.ionThis chap t er focuses m ain ly on FDD I specif icat ions and oper at ions, Inc. bu t it also pr ov id es a hig h- level ov erv iew of CDD I . By Cisco Systems, FDDI u ses d ual- r in g archit ect ur e w it h t r aff ic on each rin g f low in g in opp osit e dir ect ions ( called Pub lish er: Cisco Press count er - r ot at ing) . The d ual r ing s con sist of a pr im ar y and a secon dar y r ing. Dur ing nor m al Dat e: Sep tem ber 1 1, 2 003 operPub at ion, t h e pr im ary ring is u sed for dat a t ran sm ission , and t he secondar y r ing r em ains id le. I SBN:discussed 1- 58 705 -1 19 As w ill be in-2det ail lat er in t his chap t er , t he pr im ar y pur pose of t h e du al r in gs is t o Pages: 11 28 pr ov ide super ior r eliabilit y an d r obu st ness. Figur e 9- 1 sh ows t he coun t er - r ot at ing pr im ar y and second ar y FD DI r ings.

Figu r e ed 9 - edit 1 . ion FD DI Uses e rin- Rot t i ng Pr imr ef a erence r y an d Seconda y Riofngs The u pdat of t he b est -Coun selling talloneanet w ork ing p rov ides coverrage essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Standards pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu w ct as iv itdyev aneloped d im prbov eff Amer iciency, t heStr eader m ake t elligent cost - eff FDDI y et he icanhelp Nating ional andar ds I n stmor it ut ee (in ANSI ) X3 ,T9. 5 st anicient dar ds decisions for t h eir net w ork s. com mit t ee in t he m id- 1980 s. At t h e t im e, high- sp eed en gineerin g w or k st at ion s w ere b eg inning t o t ax t he b andw idt h of ex ist in g local- ar ea net w or ks ( LANs) based on Et her net and Tok en Ring. A n ew LAN media w as need ed t h at could easily sup por t t h ese w or k st at ion s and t heir new dist r ibut ed applicat ions. At t he sam e t im e, net w ork reliabilit y had becom e an in cr easin gly im por t ant issue as sy st em m anager s m igr at ed m ission - cr it ical app licat ions f r om lar ge com put er s t o net w ork s. FDDI w as developed t o f ill t hese need s. Aft er com plet in g t he FDDI sp ecificat ion,

ANSI subm it t ed FD DI t o t he I nt er nat ion al Or gan izat ion f or St and ard izat ion ( I SO) , w hich cr eat ed an int er nat ional v er sion of FDDI t h at is com plet ely com pat ib le w it h t h e ANSI st andar d v er sion.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

FDDI Transmission Media FDDI u ses op t ical fiber as t he pr im ary t r ansmission m edium , b ut it also can ru n ov er copper cabling. As m en t ioned ear lier , FDDI over copp er is refer r ed t o as Cop per- Dist ribu t ed Dat a I n t erf ace ( CDDI ) . Opt ical fiber h as sev eral adv ant ag es ov er copper m edia. I n par t icular, secur it y , •r eliabilit y , and Table Content s all ar e enh anced w it h opt ical f ib er media becau se fiber d oes n ot peroffor m ance •emit elect r ical I ndex sign als. A ph ysical m ed ium t h at d oes em it elect r ical signals ( copp er ) can b e It app nt e rned et wan ord k ing Teefor chnologie s ld H a ndbook th h Edit ion access t o t h e dat a t hat is t r ansit ing t he t h er e w ou per m it, Four un aut orized m ed iumSystems, . I n addit ion, fiber is im m une t o elect r ical int erf erence f r om r adio f requ en cy in t erf erence By Cisco Inc. ( RFI ) an d elect rom agn et ic in t erf er ence ( EMI ) . Fib er hist orically has sup por t ed m uch high er banPub dwlish idter: h (Cisco t hr ou ghpu t p ot ent ial) t h an copp er , alt h ough r ecent t echnological ad van ces hav e Press m ade copp er cap able of t r ansm it t ing at 1 00 Mbp s. Finally , FDDI allow s 2 k m bet w een st at ions Pub Dat e: Sep tem ber 1 1, 2 003 using m ult im ode f iber, and ev en lon ger dist ances using a sing le mod e. I SBN: 1- 58 705 -1 19 -2 11 28 FDDI dPages: ef ines t w o t yp es of op t ical fiber : sing le- m ode an d mu lt im od e. A m ode is a r ay of light t hat ent er s t he f iber at a par t icular ang le. Mu lt im od e f iber uses LED as t he light - generat in g device, w hile sin gle- m ode f iber gener ally uses laser s.

Mu lt im ode fiber allow s m ult iple m odes of light t o pr opagat e t hr ough t h e fib er . Because t hese m odes of light ent er of t het he fiber at- selling diff er ent heyw ork w illing ar r rive at t he pen d ides of t h cover e fib erage at of The u pdat ed edit ion b est all-angles, in- one tnet ef erence rov dif fer en t t im es. This char act er ist ic is kn ow n as m odal dispersion . Mod al disper sion lim it s t he essent ial an d cu t t ing- edg e t ech nologies. ban dw idt h and dist ances t hat can be accom p lished using m ult imod e fib er s. For t his r eason, m ult im ode f iber is gener ally u sed for con nect iv it y w it hin a b uilding or a r elat iv ely g eog rap hically cont ained en vir ents. of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Con cise ovonm er v iew nov ice t o ex pert . Single- m ode f iber allows only one m od e of lig ht t o p rop agat e t h rou gh t he f iber . Because on ly a singleNew m ode of ligh is u sed,cov m erag odal edisper is n ot pr esen w it hP sin mod e fib er . Th er efor e, chapt er s tinclude of imsion por t ant t opics liket VoI andgleEAP single- m ode f ib er is cap able of deliver ing con sid er ably h igher per for m ance conn ect iv it y over m uchCov lar gerag er deistofancut ces, t ing w hich edgeist echn w hy ologies it generally lik e opt is uical sednfor et wor conknect ing and iv it y st bet or w age een bu ild ings an d w it hin en vir onm ent s t hat are m or e g eog rap hically d isp er sed . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Figur e 9- 2 d ep ict s sin gle- m od e fiber u sin g a laser ligh t sour ce and m ult im ode f iber using a ligh t Iemit n t ern or k in g( LED) Tech nologies t inetgwdiode lig ht souHand rce. book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w9it- h2 new pdat red it y , stle or-M age, opt ical in g,ode scalabilit Figu re . Liganhtd uSou cechapt s Dier ffseon r fsecur or Sing ode a n dnetMwuorltk im Fibey,r s and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

FDDI Specifications FDDI specifies t he p hy sical an d media- access p ort ion s of t he OSI r ef er ence m odel. FDDI is n ot act ually a sing le sp ecificat ion, but it is a collect ion of f our separ at e specif icat ion s, each w it h a specif ic fu nct ion. Com b in ed , t hese specif icat ion s hav e t he cap abilit y t o p rov ide h igh- speed •connect ivit y bet Table of Content w een upp ers - lay er pr ot ocols su ch as TCP/ I P and I PX, and m edia such as f ib er •opt ic cab lin g.I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

FDDI 's Systems, four sp ecificat ions ar e t he Media Access Cont r ol ( MAC) , Ph ysical Lay er Pr ot ocol ( PHY) , By Cisco Inc. Phy sical- Mediu m Dependent ( PMD ) , and St at ion Manag em ent ( SMT) sp ecificat ions. The MAC specif icat ion def in es how t h e m ed ium is accessed , includin g f r ame for m at , t ok en h andling , Pub lish er: Cisco Press add ressin g, algor it hm s f or calcu lat ing cy clic redu ndan cy ch eck ( CRC) valu e, and er r or - recov er y Pub Dat e: Sep tem ber 1 1, 2 003 m ech anism s. Th e PHY sp ecificat ion defines dat a encoding / decod in g pr ocedu res, clock ing I SBN: 705d-1f19 -2 r eq uir em ent1-s,58an r amin g, am ong ot h er f un ct ion s. The PMD sp ecificat ion defines t h e Pages: char act er ist11 ics28of t he t r ansm ission m ed iu m, inclu ding f ib er - op t ic lin ks, p ow er lev els, b it - er r or r at es, opt ical comp onent s, and conn ect or s. The SMT sp ecificat ion defines FDDI st at ion conf ig ur at ion, r ing conf ig ur at ion, an d r ing cont r ol f eat ur es, in clu ding st at ion in ser t ion an d r em ov al, init ializat ion, f ault isolat ion and r ecov er y , sch ed uling, and st at ist ics collect ion. FDDI is sim t oion I EEE Et- hern et and I EEE 02.w5 ork Token in it sp rrov elat ion sh ip wage it h tof he The u pdat edilar edit of t802. he b3est selling all- inone8net ing rRing ef erence ides cover OSI m od el. I t s p r im ar y pu rp ose is t o p rov ide conn ect iv it y bet w een up per OSI lay ers of com m on essent ial an d cu t t ing- edg e t ech nologies. pr ot ocols and t h e media used t o connect n et w or k d ev ices. Figur e 9- 3 illust r at es t he four FDD I specif icat ion s and t heir r elat ion sh ip t o each ot h er and t o t h e I EEE- defined Logical Link Con t rol ( LLC) Con su blay . er Thveiew LLC sub lay erolog is aies com ponten t heprMAC lay er, refer ence ciseerov s of t echn essen ialt tof o nLayer et wor2k,ing ofession alsofatt he all OSI lev els, f rom m odel. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e -of3 cut t ing t echnicat ologies lik eMopt wor O k ing Figu re 9 . FD DIedge Specif ions a picalt on et t he SI and Hiestror a rage chi ca l M od el Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

FDDI Station-Attachment Types On e of t he u nique ch aract er ist ics of FDDI is t hat mu lt ip le w ays act u ally ex ist by wh ich t o con nect FDDI d ev ices. FDDI defines f our t y pes of d ev ices: sing le- at t ach ment st at ion ( SAS) , dual•at t achm ent st Table at ionof (Content D AS) , ssin gle- at t ached concent r at or ( SAC) , and d ual- at t ached con cent r at or •( DAC) . I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

An SAS at t aches t o only on e rin g ( t he pr im ar y) t hr oug h a concen t r at or. One of t he pr im ary By Cisco Systems, Inc. adv ant ag es of con nect in g d ev ices wit h SAS at t achm en t s is t hat t he devices w ill not hav e any eff ect on t he FDDI r ing if t hey ar e disconnect ed or pow ered off . Con cent r at or s w ill be cov ered in lish er: Cisco Press m orPub e det ail in t he f ollow ing d iscussion . Pub Dat e: Sep tem ber 1 1, 2 003

Each FDDI I SBN: DAS 1- 58 705 has -1 19 t wo -2 por t s, designat ed A an d B. These por t s connect t h e DAS t o t h e dual FDDI rPages: ing . Ther ef or e, each por t p r ovides a con nect ion f or bot h t h e pr im ary an d t he secon dar y 11 28 r ings. As y ou w ill see in t he next sect ion, devices using DAS conn ect ions will af fect t h e r ings if t hey ar e d isconnect ed or pow ered off . Figur e 9- 4 sh ows FD DI DAS A and B por t s w it h at t achm ent s t o t he pr imar y an d secon dar y r ings. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r e 9 - 4 . FD DI D AS Por t s At t a ch t o t h e Pr im a r y an d Secon da r y Ri ngs Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a r oadconcen r ang e tof al sy st em sa and ices, in clud ing det ailed descr)ipt iew quest AnbFDDI r atint oregr ( also called du al-serv at t ach m ent concen t r at or [ DAC] ision t hes, brev uilding blockions of tan o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy FD DI n et w or k . I t at t ach es d irect ly t o b ot h t he p rim ar y and secon dar y r in gs an d ensur es. t hat Cov ext-end n otany only t o new et wor k ingdow concep but. This also is t o pold , lar legacy t he erag failureeisoralso p ower dowed n of SAS does nnot br ing n t het s,ring ar ter icu ly usefu l syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent in w hiche w hen PCs, or sim ilar d ev ices t hat are fr eq uent ly p ower ed on and of f, con nect t o t he r sing. Figur pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease 9- 5 sh ows t he r ing at t achm ent s of an FDDI SAS, DAS, and concent r at or . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figu r e 9 - 5 . A Concen t r a t or At t ach e s t o Bot h t h e Pr i m ar y a nd Secon da r y Ri ng s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

FDDI Fault Tolerance FDDI p rov ides a num ber of f ault - t oler ant f eat ur es. I n par t icular , FDDI 's dual- r ing env ir on ment , t he im p lem ent at ion of t he op t ical by pass swit ch, and du al- h om in g su ppor t mak e FDDI a r esilien t m ed ia t echnology . •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Dual Ring

By Cisco Systems, Inc.

FDDI 's pr imar y f ault - t oler ant f eat ur e is t he du al ring. I f a st at ion on t he d ual r ing f ails or is Cisco powPub er lish ed er: dow n , Press or if t he cab le is dam aged, t h e du al r ing is aut om at ically w r app ed ( d oubled back Pub Dat e: Sep 1 1,le2 003 ont o it self ) int otema ber sing rin g. Wh en t he rin g is w r app ed , t he dual- r ing t opology becom es a I SBN: 158 705 -1 19 -2 a cont inu es t o be t ran sm it t ed on t he FDDI rin g w it hou t p er f orm an ce single- r in g t opology . Dat im pactPages: d ur ing 11 28t he w r ap con dit ion. Figur e 9- 6 an d Figur e 9- 7 illust r at e t h e ef fect of a r in g w r apping in FDDI .

9 -ion 6 . ofA t he Rinb est g Re coveallr sin-f rone omnet a wSt ion Fai lu rperovby Wcover r appage in g The u Figu pdat edr eedit - selling orkat ing r ef erence ides of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figu r e 9 - 7 . A Rin g al so W r a ps t o W it hst a nd a Ca bl e Fa il ur e

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing When a .sing lensthow at iont of ails, Figur e kin 9- 6g, tdechn ev ices onies eitinher of WAN t h e failed ( or ent . indu st ry Lear incoras porsh atown e intin er net w or olog t o aside LAN/ env ir onm pow er ed dow n) st at ion w r ap, for m ing a single r ing . Net wor k op er at ion cont inu es f or t h e Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, rand em ainin g st at ions on t he r ing. When a cable f ailu re occur s, as show n in Figur e 97 , d ev speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen ices t ial ton o all eit t heessionals, cab le fault w rap . Net orkpert operat nether w orsid kineg of p rof r egar dless ofwex ise. ion cont inu es for all st at ion s. IReader t shou sldwbill e not hat FD DI r uly ault t oler ance again a ksing only obt ed ain t a g reat er tun derpstrov anides ding f of LAN and WAN n etst w or ing,lep failur ar t icuelar ly t.hWhen e thar w odw or arme, ore ailur es occur , t hveices FDDI ingedseg en t s ent int oalt wt ech o ornology m or e inf indor epmat en dent s tided hat ar pr fot ocols, and ser inv rolv . Fumndam ion isring pr ov one incapab of com it hseach ot herices, . a b r oad le r ang e of m intunicat egr aling sy stwem and serv in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, prBypass ovid in g a Switch m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Optical pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient An opt ical by pass sw it ch p r ovides cont in uous d ual- r ing operat ion if a device on t he d ual r ing decisions for t h eir net w ork s. fails. This is used bot h t o pr event r ing segm ent at ion and t o elim inat e f ailed st at ions f r om t he r ing. The opt ical b yp ass sw it ch perf or ms t his f unct ion using opt ical m irr or s t h at p ass ligh t f r om t he rin g d ir ect ly t o t h e DAS device du rin g n orm al operat ion . I f a f ailu re of t he DAS device occur s, such as a p ower - off , t h e opt ical by pass sw it ch w ill p ass t he light t h rou gh it self by u sin g in t er nal m irr or s and t h er eby w ill m aint ain t he r ing 's in t eg rit y .

The b en ef it of t h is capabilit y is t hat t h e rin g w ill n ot ent er a w rap ped con dit ion in case of a dev ice f ailur e. Figur e 9- 8 sh ows t he f unct ionalit y of an opt ical b yp ass sw it ch in an FDDI net w ork . When using t he OB, y ou w ill n ot ice a t r emend ous d ig ression of y our n et wor k as t he pack et s ar e sen t t h r ough t he OB u nit .

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Figu rTable e 9 -of8Content . Thes O pt i ca l Bypa ss Sw it ch Uses I nt er n al M i r r or s t o M a in t ai n a Ne t w or k I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enablesHoming Dual net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st rydev . Lear n how int er net w or kin gs,t echn in t o- taoleran LAN/ tWAN envue ir onm ent . Cr it ical ices, sucht oasincor rou tpor er sat ore main fr am e host can olog u se ies a f ault t echniq called Com u pdat ed chapt erdancy s on secur st or age, optee icalop net k in Ig, scalabilit du al plet homeinwgit tho new pr ovan ided add it ional r edun and itt oy ,help guar ant er w ator ion. n du al- homy,ing and speed, book a com an d utpe rcent ef errence t he teop9-ics t hat are essen t ial ed t o all sit uat ions, t thheiscrit icalisd ev ice isplet at teached o ttow od at con at or s.t oFigur 9 sh ows a du al- hom net wigorurkin p rof r egaras dless of ex ise.r out er s. conf atgion foressionals, d ev ices such f ile ser verpert s and Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Figu r e 9 - 9 . A Du al -H ome d Con fi gur a t i on Gua r an t e es O pe r a t ion t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Newofchapt er s include cov erag e of imtpor antivteopics P and On e pair concent r at or link s is declared he tact link ; like t h e VoI ot her pairEAP is declar ed p assiv e. The passive link st ay s in back up m ode un t il t he pr imar y link ( or t he concent r at or t o w hich it is Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age at t ached) is det erm ined t o h ave failed . Wh en t his occur s, t he passiv e link au t omat ically act ivat es.h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Aut I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

FDDI Frame Format The FDD I fr am e f orm at is sim ilar t o t he f orm at of a Tok en Ring fr am e. This is one of t he ar eas in w hich FDD I bor r ow s heav ily f r om earlier LAN t ech nologies, su ch as Tok en Ring. FDD I fr am es can be as larg e as 4, 50 0 by t es. Figur e 9- 1 0 sh ows t he f ram e f or mat of an FD DI d at a f ram e an d •t ok en . Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 9 - 1 0 . Th e FD DI Fr am e I s Si m il ar t o Th at of a Tok en Rin g Fr am e Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

[ View full size im age]

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

FDDICov Frame erag e ofFields cut t ing edge

t echn ologies lik e opt ical n et wor k ing and st or age

Aut h ored Sy sum st ems, or ldw leader king f or I n t er n etr.at ed in Figur e The f ollow in g d by escrCisco ipt ions m arwize t heide FDD I dat ainfrnet amwe or and t ok en t he f ields illust 9- 1 0. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. er t he at er m s,uecon cep t s, t echn aneach d devices used ' s ing net w ork ing P re am blMast e— Gives uniq seq uence t hat ologies, pr epar es st at ion f or in an t oday up com f ram e. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet it hlinew du ed er s on secur st or age, opt ical net or knaling in g, scalabilit St aertwde m it ean r— I npdat dicat eschapt t he begin ning of it a yf,r ame by em ployin g awsig pat t er n y,t hat and speed, t ht iat is book a com antdheu pt o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all dif fer en es it frisom t he plet r este of f r ame. net w or kin g p rof essionals, r egar dless of ex pert ise. Fra m e cont rol— I n dicat es t he size of t he ad dr ess f ield s and w het her t h e fr am e cont ains Reader s wch ill robt ain or a gsy reat er onou un der ana,ding of gLAN andcont WAN et w k ing, asyn onous nchr s st dat amon ot her r olninf oror mat ion .p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad D e st r ang i naet ion of int a egr ddral ess— sy st em Cont s and ains serv a unices, icastin( sin cludgular ing det ) , mailed ult icast descr ( gipt rou ion p)s, , or revbriew oadcast quest ions t o en su ( ever re con y stcept at ion) comp addr r eh ess. en sion As wand it h Et r et her ennet t ion, and and Tok aden ditRing ional addr r esou esses, r ces fFDDI or fu rtdher est inat st udy ion. Cov erag adderesses is alsoarext e 6end byed t esnlong ot only . t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Sou rce ad dre I d enand t ifies heelines sing lef or st at ion h at sent t he per f ram e.mAs w it w h ill Et hincr er nease et and pr of essionals oper atss— e. Tools gut id opt imtizing syst em for ance ad pr dr ov esses, FD DI sour ceing addr esses ar e m 6 ake by t es long. pr oduTok ct iven it y Rin an dg im e eff iciency, help t he r eader mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. D a t a— Cont ains eit h er in for m at ion dest in ed for an upper - lay er p r ot ocol or cont r ol inf orm at ion. Fra m e ch eck se que nce ( FCS) — I s filed b y t he sour ce st at ion wit h a calculat ed cy clic r ed und ancy check value dependent on fr am e con t ent s ( as wit h Tok en Rin g and Et her net ) . The d est inat ion ad dr ess r ecalculat es t h e valu e t o d et er m ine w het her t h e fr am e w as

dam aged in t ran sit . I f so, t he f ram e is d iscar ded. End de li m it e r— Cont ains uniqu e sym bols; can not be dat a sym bols t hat in dicat e t he end of t he fr am e. Fra m e st a t us— Allow s t h e sour ce st at ion t o det erm ine w h et h er an er r or occu rr ed; ident if ies w h et h er t he f ram e w as r ecognized and cop ied by a r eceivin g st at ion. •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Copper Distributed Data Interface Cop per Dist r ib ut ed Dat a I n t er f ace ( CDDI ) is t he im plem en t at ion of FDD I pr ot ocols over t w ist edpair copp er w ir e. Lik e FDDI , CDDI p rov ides dat a r at es of 100 Mb ps an d u ses d ual- r in g ar ch it ect u re t o pr ov ide r edun dancy . CDD I supp ort s dist ances of about 100 m et ers f r om deskt op •t o con cent r atTable or . of Content s •

I ndex

ICD nt eDI rn et or k ing chnologie s H a ndbook th mit Edittion iswdef in edTeby t he ANSI X3 T9.,5Four Com ee. The CDDI st an dar d is off icially nam ed t he Tw ist ed Pair Phy sical Med iu mDep en dent ( TPPMD) st andar d. I t is also r efer red t o as t he By Cisco Systems, Inc. Tw ist ed - Pair Dist rib ut ed D at a I nt er face ( TP- D DI ) , consist en t w it h t he t er m Fiber Dist r ib ut ed Dat a I nt erf ace ( FDDI ) . CD DI is consist en t w it h t he phy sical an d media- access cont r ol lay er s Pub lish er: Cisco Press defin ed by t he ANSI st and ar d. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN:st1705d -1 19 -2 The ANSI an58dar recognizes only t wo t y pes of cables for CDDI : sh ielded t w ist ed pair ( STP) and un sh ielded Pages: t11 w28 ist ed pair ( UTP) . STP cabling has 1 50- oh m im pedance and adh er es t o EI A/ TI A 56 8 ( I BM Ty pe 1) sp ecificat ions. UTP is d at a- gr ade cabling ( Cat eg ory 5) consist ing of fou r unsh ielded pair s using t igh t - pair t w ist s an d specially d ev eloped in su lat in g polym er s in p last ic jacket s adh er ing t o EI A/ TI A 56 8B specificat ions.

Figur e 9- 1 1 illust r at es t he CDDI TP- PMD sp ecificat ion in r elat ion t o t he r em aining FDDI The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of specif icat ion s. essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

Figunov r eice 9 -t1o 1ex. pert CDD . I TP- PM D an d FD DI Specif ica t i ons Adhe r e t o Di ff e r en t Stan da r ds New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary The Fiber Dist r ibut ed Dat a I nt erf ace ( FDDI ) specifies a 1 00- Mbps t oken- p assing , dual- r ing LAN ar ch it ect u re usin g fiber - opt ic cable. FDDI is f r eq uent ly im plement ed as a high- sp eed backb one t echnology b ecau se of it s su ppor t for h ig h band wid t h an d gr eat er d ist an ces t h an cop per. •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What ar e t he benefit s of using FDDI in st ead of CD DI ?

2:

I ndex r ole does t he DAC play in t he FDDI net w ork ? What

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Part III: WAN Technologies Ch apt er 10 Fr am e Relay • •

Ch apt er 11 Hig h- Speed Ser ial I nt er face Table of Content s

Ch apt er 12 I n t eg rat ed Serv ices Digit al Net w or k I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ch apt er 13 Poin t - t o- Point Pr ot ocol

By Cisco Systems, Inc.

Ch apt er 14 Sw it ched Mult im egabit Dat a Ser v ice

Cher: aptCisco er 15 D ialu p Pub lish Press

Techn olog y

Pub Ch Datapt e: Sep 1, 2 003 er tem 16ber Sy1nchr on ous

Dat a Link Cont r ol an d Der iv at ives

I SBN: 1- 58 705 -1 19 -2

Ch apt er 17 X. 2 5

Pages: 11 28

Ch apt er 18 Vir t ual Pr iv at e Net w or ks ( VPNs)

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 10. Frame Relay Obj e ct i ve s • •

Table of Content s

Descr ibe t he hist or y of Fram e Relay . I ndex

I nt e rn Descr et w or kibe ing Te chnologie a ndbook , Four h ow Fr ames HRelay w or k s. th Edit ion By Cisco Systems, Inc.

Descr ibe t he pr im ar y fun ct ion alit y t r ait s of Fr am e Relay . Pub lish er: Cisco Press

Descr ibe Fr am e Relay net w or k imp lem ent at ion.

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: ibe 1- 58t705 19 -2 at of Fr am e Relay fr am es. Descr he -1 f orm Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction Fram e Relay is a high - per for m ance WAN p rot ocol t hat operat es at t he phy sical and dat a lin k lay er s of t h e OSI r efer en ce m od el. Fr am e Relay orig in ally was desig ned f or use acr oss I nt egr at ed Ser v ices Digit al Net w or k ( I SDN) int er faces. Tod ay, it is used over a var iet y of ot her •net w or k int erTable Content facesofas w ell.s Th is chapt er f ocu ses on Fr ame Relay ' s sp ecificat ions and applicat ions •in t he cont exItndex of WAN ser v ices. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Fram e Relay is an By Cisco Systems, Inc.ex amp le of a pack et - sw it ched t ech nology . Packet - sw it ched n et wor k s enable end st at ions t o dy nam ically shar e t h e net w or k m ed iu m and t h e available b andw idt h . The follow ing t w o t echn iq ues ar e used in pack et - sw it ching t echnolog y: Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

Var I SBN: iable1- 58leng 705 -1t h 19 packet -2 s Pages: 11 28

St at ist ical m ult iplexing Var iable- leng t h packet s ar e u sed for m or e eff icient and flex ib le dat a t r ansfer s. These p ack et s ar e sw it ch ed bet w een t h e v arious segm ent s in t h e net w ork unt il t he dest inat ion is r eached. The u pdat edit ion of tthe b est - es selling in- one w ork ing erence p rov idesnet cover age ofe St at ist ical ed m ult iplexing echniqu con t rallol net w or knet access in ar ef pack et - sw it ched w ork . Th essent anof d tcu t t ingedg adv antial ag e his t echn iq e uet ech is t nologies. h at it accom m odat es m or e flexib ilit y an d mor e eff icient use of ban dw idt h. Most of t od ay' s pop ular LANs, such as Et hern et and Tok en Rin g, ar e pack et - sw it ched net w or ks. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom ice t o Fram enov Relay ofex t enpert is d. escr ibed as a st r eam lined ver sion of X. 25, off er ing f ew er of t he rob ust capabilit ies, su ch as w ind ow in g an d ret r ansm ission of last dat a t hat ar e off er ed in X. 25 . This is NewFram chapt s include cov erag por WAN t ant t opics liket hVoI because e er Relay t y pically opereatof es im over facilit ies at P ofand fer mEAP or e r eliable conn ect ion ser v ices an d a high er degr ee of r eliabilit y t han t he facilit ies av ailab le dur ing t h e lat e 19 70s an d Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age early 1 980 s t hat ser v ed as t he com mon p lat f or m s for X. 2 5 WANs. As m ent ion ed earlier , Fram e RelayAut is st r ict ly by a Lay er 2 ocolwsu e, w hereas 25net pr ov ides v ices h ored Cisco Sypr stot ems, oritldw ide leaderX.in w or kingser f or t he at I n tLay er ner et .3 ( t he n et w or k lay er ) as w ell. Th is en ables Fr am e Relay t o off er h igher p er for m ance an d g reat er t r ansm ission eff t han 25 , and m akes Fr am e Relay able for WAN ap plicat ionence s, su ch as LAN I n ticiency ern et w or k in gX.Tech nologies Hand book , Four su t h itEd it ion , iscuar rent com pr ehensive refer t hat int er con nect ion . enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet eRelay w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Frame Standardization and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. I nit ial p rop osals f or t h e st andar dizat ion of Fram e Relay w er e pr esent ed t o t h e Con su lt at ive Com m it t ee on I n t er n at ional Telep hone an d Telegr aph ( CCI TT) in 198 4. Because of lack of Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e int er operab ilit y and lack of com plet e st and ard izat ion , how ev er , Fr am e Relay did not ex per ien ce har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on signif icant deploy m en t d ur in g t he lat e 1 980 s. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . A m aj or dev elopm ent in Fr am e Relay' s hist or y occu r red in 1 990 w hen Cisco, Digit al Equip ment Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Cor por at ion ( DEC) , Nor t her n Telecom , and St rat aCom f orm ed a consor t ium t o focus on Fr am e syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Relay t ech nology d ev elopm en t . This con sor t ium developed a specif icat ion t h at conf orm ed t o t h e pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease basic Fr ame Relay p r ot ocol t hat w as being discu ssed in CCI TT, but it ex t ended t he p rot ocol w it h pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient feat u res t h at p rov ide ad dit ional capab ilit ies f or comp lex in t er net w or k in g en vir onm ent s. These decisions for t h eir net w ork s. Fram e Relay ex t ension s ar e r ef er r ed t o collect ively as t h e Local Managem en t I nt er face ( LMI ) . Since t he con sor t ium ' s specif icat ion w as dev elop ed and p ublished, m any v endor s h ave ann ounced t heir su ppor t of t his ex t en ded Fr am e Relay definit ion . ANSI and CCI TT hav e subsequent ly st an dar dized t heir ow n v ar iat ions of t he orig in al LMI specif icat ion, and t hese st andar d ized specif icat ion s now ar e m or e com mon ly used t h an t he or iginal v er sion.

I nt er nat ionally , Fram e Relay w as st and ar dized b y t he I nt er nat ion al Telecom mu nicat ion Union—Telecom m unicat ions St an dar ds Sect ion ( I TU- T) . I n t he Unit ed St at es, Fr am e Relay is an Am er ican Nat ion al St and ar ds I nst it ut e ( ANSI ) st andar d.

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Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Frame Relay Devices Dev ices at t ached t o a Fram e Relay WAN fall in t o t h e follow ing t w o g en er al cat egor ies:

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Dat a t erm Table inal of eq Content uipmsent ( DTE) I ndex

a kcir - t er m in at ing equipm ent DCE) I nt e rn Dat et w or ingcuit Te chnologie sH a ndbook , Four th (Edit ion By Cisco Systems, Inc.

DTEs gener ally ar e consider ed t o be t er m in at ing eq uipm ent for a specif ic net w ork and t y pically ar e locat ed on t he p r em ises of a cust om er . I n fact , t hey m ay be ow ned by t h e cust om er . Pubples lish er:ofCisco Ex am DTEPress dev ices ar e t erm inals, p er sonal com pu t er s, r out er s, and br idges. Pub Dat e: Sep tem ber 1 1, 2 003

DCEs ar e carr ierI SBN: 1- 58 705own -1 19 ed -2 int er net w or kin g d ev ices. Th e pur pose of D CE eq uipm ent is t o pr ov ide clock ing and sw it ch in g ser vices in a net w or k, w hich ar e t h e devices t hat act ually t r ansm it dat a Pages: 11 28 t hr ou gh t he WAN. I n m ost cases, t h ese ar e p ack et sw it ches. Figur e 10 - 1 sh ows t he r elat ion sh ip bet w een t h e t w o cat egor ies of devices.

TheFigu u pdatred ion. of t he b est all-Resid in- one net w ork ef erence rov idesa cover age of e 1edit 0 -1 D CEs Ge- selling ne r al ly e W i t hing in rCar r i er -pO per te d W ANs essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . The con nect wend eened a DTE device and an et DCE consist of bot h at ophy lay er Cov erag e is ion alsobet ext n ot only t o new wordev k ingiceconcep t s,s but also oldsical er , legacy com ponent and in a glink ysical t h vir e monm echan syst em s, pr ovid a mlay orer e rcomp ealist onent ic pict.urThe e ofph t he real-comp w or ldonent n et wdefines or k ing en entical, s in w hich elect r ical, f un ct ion at al,e.and pr oced forizing t he syst connem ectper ion for betmwance een twhe ev ices. pr of essionals oper Tools and ur gualid specif elinesicat f or ion optsim ill dincr easeOne of t he ctmost only phy sical help layer er face specificat e recom, mend ed icient st and ar d pr odu iv it y com an dmim pr ovuesed eff iciency, ingintt he r eader m ake ions mor eisint ht elligent cost - eff (decisions RS) - 2 32 for specif icatnet ionw. ork Thes.link lay er comp onent defines t h e pr ot ocol t hat est ablish es t he t h eir connect ion bet w een t he D TE d ev ice, su ch as a r out er, and t he D CE device, such as a sw it ch . This chapt er ex am in es a com mon ly ut ilized p rot ocol specificat ion used in WAN net w or k in g: t he Fr ame Relay pr ot ocol.

Frame Relay Virtual Circuits Fram e Relay p rov ides conn ect ion- or ient ed d at a link lay er com mu nicat ion . This m eans t hat a defin ed com mu nicat ion ex ist s bet w een each pair of d ev ices an d t hat t hese con nect ion s ar e associat ed wit h a con nect ion ident if ier . Th is ser v ice is im plem en t ed b y using a Fr ame Relay •v irt u al circuitTable of Content s , w hich is a logical con nect ion cr eat ed bet w een t w o dat a t er m inal equ ipm en t ( D TE) •dev ices acr oss I ndex a Fram e Relay p ack et - sw it ch ed net w or k ( PSN) . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Vir t ual cir cu it s pr ov id e a b idirect ional com m unicat ion pat h fr om one DTE dev ice t o anot h er and By Cisco Systems, Inc. ar e un iq uely ident ified by a dat a- link conn ect ion ident ifier ( DLCI ) . A num ber of v ir t ual cir cu it s can be m ult iplexed int o a single p hy sical cir cu it f or t r ansm ission acr oss t he n et wor k . This Pub lish er: Cisco Press capabilit y of t en can r ed uce t he equ ip m en t an d n et w or k com plexit y r equir ed t o conn ect mu lt ip le Dat e: Sep tem ber 1 1, 2 003 DTEPub dev ices. I SBN: 1- 58 705 -1 19 -2

A v ir t ual Pages: cir 11 cuit 28 can pass t hr ou gh any nu m ber of int er mediat e D CE devices ( sw it ch es) locat ed w it hin t he Fr am e Relay PSN. Fram e Relay v ir t ual cir cu it s fall in t o t w o cat eg ories: sw it ch ed v ir t ual cir cu it s ( SVCs) an d per m anent v ir t ual cir cuit s ( PVCs) . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Switched Virtual Circuits

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Sw it ch ed v ir t ual circuit s ( SVCs) ar e t em por ar y connect ions u sed in sit uat ion s r eq uir in g only nov ice t o ex pert . spor adic dat a t r ansfer b et ween DTE devices acr oss t h e Fr am e Relay net w or k . A com m unicat ion session acr oss an SVC consist s of t he follow in g four operat ion al st at es: New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Cal l se t up — The v irt u al circuit bet w een t w o Fr am e Relay DTE dev ices is est ablish ed . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . D a t a t ra nsfe r— Dat a is t ran sm it t ed bet w een t he DTE devices over t h e v ir t u al cir cuit . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat I dl e— The connect ion bet w een DTE devices is st ill act iv e, bu t n o dat a is t r ansf er r ed . I f an enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing SVC rem ains in an idle st at e for a d ef ined p er iod of t ime, t he call can b e t erm inat ed . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu stCal ry . l Lear n ina howt i on to — incor por at ue al intcircuit er net wbet or kin g t echn ies inist ot er am LAN/ t er m The v irt w een DTE olog dev ices in atWAN ed. env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, anderspeed, a tcom plet eedan u po- ddevices at e r ef er ence t o ablish t he t op t hat areif essen ial t o all Aft t he v irtt huis al book circuitis is er minat , d t he D tTE mu st est a ics new SVC t here tis net wit or p rof r egar dless pert add ionkin al gdat a tessionals, o be exchan ged. I t isofexex pect edise. t hat SVCs w ill be est ablished, m aint ained, and t er min at ed using t h e sam e sign alin g p rot ocols u sed in I SDN. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har e, pr ser vRelay ices inv olv ed . Fu ndam ent al t tech pr ov ided Fewdw mar anuf actotuocols, r er s ofand Fr ame DCE equipm ent su ppor swnology it ched inf v ir or t u mat al cirion cuitis con nect ionon s. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Ther ef or e, t heir act ual d ep loy m ent is min im al in t od ay' s Fram e Relay n et w or k s. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov e isnot also ext end n ot t o ame new Relay n et woreq k ing concep t s, but er , m legacy Pr everag iously w idely sued ppor t edonly by Fr uipm en t , SVCs arealso nowt ot hold e nor . Com pan ies syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in hav e f ound t h at SVCs sav m oney in t he end because t he cir cuit is n ot op en all t h e t im e. w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Permanent Virtual Circuits

Perm an en t v ir t u al cir cu it s ( PVCs) ar e p er m anent ly est ablished conn ect ions t hat are used f or fr equ en t and consist en t d at a t r ansf er s b et w een D TE d ev ices acr oss t he Fr am e Relay net w or k. Com m un icat ion across a PVC d oes not requ ir e t he call set u p and t er m inat ion st at es t hat ar e

used wit h SVCs. PVCs alw ays op er at e in one of t he f ollow ing t w o operat ion al st at es: D a t a t ra nsfe r— Dat a is t ran sm it t ed bet w een t he DTE devices over t h e v ir t u al cir cuit . I dl e— The connect ion bet w een DTE devices is act ive, b ut no d at a is t r ansf er r ed. Unlike SVCs, PVCs w ill not b e t erm inat ed un der any cir cu m st an ces w h en in an id le st at e. •DTE dev ices Table of Content s can begin t r ansferr ing d at a w henev er t hey ar e r ead y becau se t he cir cu it is •per m anent ly I est ndex ablish ed . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Data-Link Connection Identifier Pub lish er: Cisco Press Pub e: Sep ber 1cir 1, cu 2 003 Fram e Dat Relay v tem ir t ual it s ar e ident ified by dat a- link connect ion ident ifier s ( DLCI s) . D LCI v alues t y pically are1-assigned I SBN: 58 705 -1 19 -2by t h e Fram e Relay serv ice pr ov id er ( for ex am ple, t he t elephon e com pany ) . 11 28 Pages:

Fram e Relay D LCI s h ave local signif ican ce, w h ich m ean s t hat t heir v alues ar e uniq ue in t he LAN, bu t n ot necessar ily in t h e Fram e Relay WAN. Figur e 10 - 2 illust r at es how t w o dif fer en t DTE d ev ices can be assigned t he sam e DLCI v alue The u pdat editeion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of w it hin oneed Fr am Relay WAN. essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Figu r e 1 0 -2 . A Sin gle Fr am e Rel ay Vi r t u al Cir cu it Can Be Assi gne d nov ice t o ex pert . Di f fe r en t DLCI s on Ea ch En d of a VC New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Congestion-Control Mechanisms Fram e Relay r educes net w or k ov er head by im plem en t ing sim ple cong est ion- not ificat ion m ech anism s r at h er t han ex plicit , per - v ir t u al- cir cuit f low cont r ol. Fr ame Relay t yp ically is im plem ent ed on reliable net w or k m edia, so dat a int egr it y is n ot sacrif iced becau se flow cont rol •can be left t oTable of Content h ig herlay er spr ot ocols. Fr am e Relay im plement s t w o cong est ion- n ot ificat ion •m ech anism s:I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Forw ar d- ex plicit congest ion not ificat ion ( FECN)

PubBackw lish er: Cisco Press ar d- ex plicit

congest ion n ot ificat ion ( BECN)

Pub Dat e: Sep tem ber 1 1, 2 003

FECN and each is cont r olled by a single b it cont ained in t he Fram e Relay f r ame header. I SBN:BECN 1- 58 705 -1 19 -2 The FrPages: am e Relay fr am e header also cont ain s a D iscar d Elig ibilit y ( DE) bit , w h ich is used t o 11 28 ident if y less im por t ant t r aff ic t hat can b e dr opp ed du rin g p er iods of con gest ion . The FECN bit is par t of t h e Addr ess field in t he Fr am e Relay fr am e header . Th e FECN m echanism is init iat ed wh en a DTE device sends Fr am e Relay fr am es int o t he net w or k . I f t he net w or k is congest ed, DCE d ev ices ( sw it ches) set t h e v alu e of t he f r ames' FECN bit t o 1. W hen t he fr am es The u pdat ion he dbev est - selling all-rinnet witork r ef erence p rov cover aget he of r each t he ed destedit in at ionofD tTE ice, t he Add essone f ield (w h ting he FECN bit set ) inides dicat es t hat essent ial an d cu t t ingedg e t ech nologies. fr am e ex perienced cong est ion in t he pat h f r om sour ce t o dest inat ion. The DTE d ev ice can r elay t his in for m at ion t o a higher - layer p rot ocol for p rocessing . Dependin g on t h e imp lem ent at ion , flow con t r ol m ay be in it iat ed, or t he in dicat ion m ay b e ignor ed. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice o ex pert The BECN bit t is par t of. t h e Addr ess field in t he Fr am e Relay fr am e header . DCE devices set t he v alue of t he BECN bit t o 1 in f r ames t r av eling in t he opposit e dir ect ion of f ram es w it h t heir FECN New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP bit set . This inf orm s t h e r eceiving DTE d ev ice t hat a p art icular p at h t hr ough t h e net w or k is congest ed. The DTE t h ent echn can ologies relay t his for m at ion t o akhing igher - layer p rot ocol f or Cov erag e of cutdevice t ing edge lik einopt ical n et wor and st or age pr ocessing. Depending on t he im p lem ent at ion, flow - cont r ol m ay be in it iat ed , or t h e indicat ion m ay be . Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Autig h nor orededby I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables w or kinDiscard g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Framenet Relay Eligibility t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . The Discar d Eligib ilit y ( DE) b it is used t o in dicat e t hat a f r am e has low er imp or t ance t han ot h er Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, fr am es. The DE b it is par t of t he Ad dr ess f ield in t he Fr ame Relay f r am e header. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. DTE dev ices can set t he v alue of t h e DE bit of a f ram e t o 1 t o ind icat e t hat t he f ram e h as low er im por t ance t han ot h er fr am es. Wh en t h e net w or k becomes cong est ed, D CE devices w ill discar d Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e fr am es w it h t he DE b it set befor e d iscar ding t hose t h at d o not . This r educes t he lik elih ood of har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on crit ical d at a b eing d rop ped b y Fram e Relay DCE devices dur ing per iods of congest ion. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, Relay Frame pr ovid in Error g a m or Checking e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr oduectRelay iv it y an d ima pr ov emeff help ing heech r eader ake , costdancy - eff icient Fram u ses com oniciency, err or - check ing tm anismmkn owmor n ase tin het elligent cyclic r edun check decisions for t h eir net w ork s. ( CRC) . Th e CRC com par es t w o calcu lat ed v alues t o d et er m ine w het her er r ors occur r ed d ur in g t he t ran smission f rom sou r ce t o dest inat ion. Fr am e Relay r ed uces net w ork over head b y im plem ent in g er r or check ing r at her t han er ror cor r ect ion . Fram e Relay t y pically is imp lem ent ed on r eliable n et w or k m edia, so d at a int egr it y is n ot sacr if iced because er r or cor rect ion can be lef t t o higher - layer p rot ocols r un ning on t op of Fr am e Relay .

Frame Relay Local Management Interface The Local Man agem ent I nt er face ( LM I ) is a set of enhan cem en t s t o t he b asic Fr am e Relay specif icat ion . The LMI w as d ev elop ed in 19 90 by Cisco Sy st em s, St r at aCom , Nor t h er n Telecom , and Dig it al Equ ipm en t Corp orat ion . I t of fer s a n um ber of f eat u res ( called ex t en sion s) for •m anagin g com Table of int Content plex er nets w ork s. Key Fram e Relay LMI ext en sions in clu de glob al add ressin g, •v irt u al circuitI ndex st at us m essag es, an d m ult icast ing. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

The LMISystems, g lob al add By Cisco Inc. ressin g ex t ension g ives Fr ame Relay d at a- link conn ect ion ident ifier ( DLCI ) v alues global rat h er t han local sig nificance. DLCI v alu es becom e D TE ad dr esses t hat ar e uniq ue in t he Fr ame Relay WAN. The g lobal add r essing ex t ension ad ds f unct ionalit y an d man ageabilit y Pub lish er: Cisco Press t o Fr am e Relay int er net w ork s. I nd iv idu al net w or k int erf aces and t he end nod es at t ached t o Pub Dat e: Sep tem ber 1 1, 2 003 t hem , f or exam ple, can be ident if ied by usin g st an dar d addr ess- r esolu t ion an d d iscov er y I SBN: 705 -1it19 -2 , t he en t ir e Fr am e Relay net w or k appear s t o be a t yp ical LAN t o r out ers t echniqu es. 1-I n58add ion 11 28y. on it s Pages: per ipher LMI vir t u al cir cuit st at us m essages p rov ide com m unicat ion and sy nchr on izat ion b et w een Fr am e Relay DTE and DCE d ev ices. Th ese m essages ar e u sed t o p er iodically repor t on t he st at u s of PVCs, w hich pr event s dat a f r om being sen t int o black holes ( t h at is, ov er PVCs t h at no longer exist The u) .pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The LMI m ult icast ing ex t ension allow s m ult icast g rou ps t o be assigned. Mult icast in g sav es ban dw idt h by allow ing r out ing up dat es and add r ess- r esolut ion m essages t o be sen t on ly t o specifCon ic grcise oupov s of e exolog t ension also ttial r ansmit repor t s on t h e st atals us of icast rou ps er vrou iewt ers. s of Th t echn ies essen t o n ets wor k ing pr ofession at m allult lev els, gf rom in updnov at eice m essages. t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Frame Relay Network Implementation A com m on pr iv at e Fr am e Relay net w or k imp lem ent at ion is t o eq uip a T1 m ult iplexer w it h bot h Fram e Relay an d n on- Fr ame Relay in t erf aces. Fr ame Relay t raf fic is f or w ard ed out t he Fr am e Relay int er face and ont o t h e dat a net w ork . Non - Fr am e Relay t r aff ic is for w ar ded t o t h e •app rop riat e applicat Table of Content ion or sser vice, such as a p riv at e br an ch exchan ge ( PBX) for t elephon e •ser v ice or t o Iandex v id eo- t eleconfer en cin g ap plicat ion . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

A yp ical Fr am eInc. Relay net w or k con sist s of a num b er of D TE d ev ices, such as r out er s, connect ed By tCisco Systems, t o rem ot e por t s on m ult ip lex er eq uipm ent via t rad it ional p oin t - t o- poin t serv ices such as T1 , fr act ional T1, or 5 6- Kb cir cuit s. An exam ple of a sim p le Fr am e Relay net w or k is show n in Figur e Pub lish er: Cisco Press 10 - 3. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 1 0 -3 . A Sim pl e Fr a m e Re la y Ne t w or k Con ne ct s Var i ous D ev ices t o Di ff e r en t Se r vi ces ov er a W AN The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The m aj or it y of Fr am e Relay net w or ks deployed t oday are p r ovisioned b y ser v ice p r ovider s t hat int end t o off er t ran sm ission serv ices t o cust om er s. Th is is oft en ref er r ed t o as a pub lic Fr am e Relay ser v ice. Fr am e Relay is imp lem ent ed in b ot h p ublic car r ier - pr ov ided n et w or k s and in pr iv at e ent erp r ise n et w or k s. The f ollow ing sect ion exam ines t h e t w o m et hod olog ies f or deploy ing Fram e Relay .

Public Carrier-Provided Networks I n pub lic car r ier - pr ov ided Fr am e Relay net w or ks, t h e Fr am e Relay sw it ch ing eq uipm ent is locat ed in t he cent r al of fices of a t elecom m unicat ions car r ier . Su bscr iber s ar e char ged b ased on t heir n et w or k use b ut are r eliev ed f r om adm inist erin g an d m aint ain ing t he Fr ame Relay net w ork equipm ent and ser v ice. •

Table of Content s

•Gener ally , t hIendex DCE equ ip m en t also is ow ned by t h e t elecom m unicat ions p rov ider . DCE Iequipm nt e rn et w or k eit ing her Te chnologie H a ndbook Four th Edit ent w ill be scust om er -,ow n ed or ion p er hap s w ill be ow ned by t h e t elecom m unicat ions pr ov ider as a ser vice t o t he cust om er. By Cisco Systems, Inc.

The m aj or it y of t oday 's Fr am e Relay net w or ks ar e p ublic car rier - pr ov id ed n et w or k s. Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Private Enterprise Networks Pages: 11 28 Mor e f requ en t ly, org anizat ions w or ldw ide ar e d ep loy ing pr iv at e Fram e Relay n et w or k s. I n pr iv at e Fram e Relay n et w or k s, t he ad min ist r at ion and m aint enance of t h e net w ork are t he r espon sib ilit ies of t he en t er pr ise ( a pr iv at e com pan y) . All t he equ ip m en t , includin g t h e sw it ch in g equipm ent , is ow ned b y t he cu st om er . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Frame Relay Frame Formats To u nder st and m uch of t he f unct ionalit y of Fr ame Relay , it is helpfu l t o und er st and t he st r uct u re of t he Fr am e Relay fr am e. Figur e 10 - 4 d ep ict s t he b asic f or mat of t he Fr am e Relay fr am e, and Figur e 10 - 5 illust r at es t he LMI v ersion of t he Fr am e Relay fr am e. •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Figu r e 1 0 -4 . Fiv e Fi el ds Com p r ise t he Fr a m e Re la y Fr a m e

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu re 1 0ov-5 N in e Fi el ds pr i se am e Rel ay Thals at atConf or m fsrom to Con cise er .v iew s of t echn ologCom ies essen t ial tt he o n etFr wor k ing pr ofession all lev els, nov ice t o ex pert . t h e LM I For m at New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP [ View full size im age]

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet w iteh t new an d uing pdatand ed chapt secur y ,ree st orprage, ical pnet w orsk m in g, Flags indeicat h e beginn end ofertsheonf ram e. itTh im aropt y com onent ak escalabilit up t he y, and speed, book t is plet d u pt o-area, d at e trhefeeruserenced tat o at he t op t hatt hare t ial t o all Fram e Relayt hfis r ame: heah com ead er anedan addr ess p ort ionics , and e fressen am e check net w or kin g p rof .essionals, r egar ex is pert seq uence ( FCS) Th e addr ess ardless ea, w of h ich 2 ise. by t es in leng t h, is com pr ised of 10 bit s r ep r esent ing t he act u al circuit ident ifier an d 6 bit s of field s r elat ed t o cong est ion m anagem ent . Reader sw ainmaonly g reat un der ding LAN andconnect WAN n ion et w or k ing, p ar t icu lar t h e of This id en t ifillierobt com is er r efer r ed stt oanas t heofd at a- link id en t ifier ( DLCI ) . ly Each har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on t hese is discussed in t he descript ion s t hat follow . a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Standard Frame Frame syst em s, pr ovid in g a mRelay or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease St and ct ard e im Relay con sisthelp of ting he tf he ields illust rm atake ed in Figur 10 - 4. , cost - eff icient pr odu iv itFry am an d pr ovfream effes iciency, r eader mor e inet elligent decisions for t h eir net w ork s. The f ollow in g d escr ipt ions sum m ar ize t he b asic Fr am e Relay fr am e fields illust r at ed in Figur e 10 4. Fla gs— Delim it s t h e beginn in g and en d of t he fr am e. The v alue of t his field is alw ay s t h e sam e and is r ep resen t ed eit her as t he hex adecim al n um ber 7E or as t he b in ary num ber

01 111 110 . Ad dre ss— Cont ains t he f ollow ing inf or mat ion : - D LCI — The 10 - bit DLCI is t he essence of t h e Fram e Relay h ead er . Th is value r ep r esent s t h e v ir t u al connect ion b et ween t he DTE d ev ice and t he sw it ch. Each v irt u al connect ion t hat is mu lt iplex ed ont o t he ph ysical chann el w ill be r ep r esent ed by a un iq ue D LCI . Th e DLCI valu es hav e local sign ificance only , w hich means t hat t hey ar e • Content s unTable iq ueofon ly t o t h e phy sical ch annel on w hich t hey r eside. Th er efor e, dev ices at • I ndex opp osit e end s of a conn ect ion can u se diff er ent DLCI v alu es t o r efer t o t he sam e I nt e rn et w or k ing chnologie sH a ndbook , Four th Edit ion v irtTe u al connect ion. By Cisco Systems, Inc.

Pub lish er: Pub Dat e: I SBN:

- Ex t en de d A ddre ss ( EA) — The EA is used t o indicat e w h et h er t he by t e in w hich tCisco he EA v alue is 1 is t h e last add ressin g f ield . I f t he v alue is 1 , t hen t he cur r ent by t e is Press det er min ed t o be t h e last DLCI oct et . Alt houg h cu rr ent Fr am e Relay im plement at ion s Sep tem ber 1 1, 2 003 all use a t w o- oct et DLCI , t his capab ilit y does allow longer DLCI s t o be used in t h e 1- 58 705 -1 19 -2 fu t ur e. The eigh t h bit of each b yt e of t he Ad dr ess f ield is used t o ind icat e t h e EA.

Pages: 11 28

- C/ R— The C/ R is t h e bit t hat follow s t he m ost sign ificant DLCI by t e in t he Ad dr ess field. Th e C/ R bit is not cu r rent ly d ef ined. - Conge st ion Con t rol— This consist s of t he 3 bit s t hat con t rol t he Fr am e Relay The u pdat edcongest edit ionionof not t heifbicat estion - selling m echallanisms. in- oneTh net ese w ork ar eing t h er ef FECN, erence BECN, p rov ides and cover DE b itage s, wof h ich essent ial anar d ecut he t t inglastedg 3 be itt ech s in nologies. t he Add r ess f ield. Con cise ov er of t echn ologion ies not essen t ial n et wor is k ing pr ofession als at all can lev els, f rom Forw arvd-iew exsplicit congest ificat iont o( FECN) a singlebit field t h at be set to a nov icev talue o ex of pert . 1 by a sw it ch t o in dicat e t o an end DTE dev ice, such as a r out er , t h at congest ion was ex per ien ced in t he dir ect ion of t he fr am e t r ansm ission f r om sour ce t o New chapt er s ion. include erag of im poroft ant opics P and dest inat Thecov pr im ar ye benefit t he tuse of like t h e VoI FECN andEAP BECN fields is t h e capabilit y of hig her- lay er pr ot ocols t o r eact int elligent ly t o t hese con gest ion Cov erag e of or cuts.t ing edge t echn ologies lik earopt n et wor ing lay and indicat Today , DECnet and OSI e t hical e only hig kherer st prorotage ocols t hat im plem ent t hese capabilit ies. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Backw ar d- ex plicit congest ion not ificat ion ( BECN) is a single- bit field t h at , w hen set t o I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat a v alue of 1 b y a sw it ch , ind icat es t h at cong est ion w as ex per ien ced in t he net w or k in enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t he dir ect ion opposit e of t h e fr am e t r ansm ission fr om sour ce t o d est inat ion . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n howelig t o ibilit incorypor at eisintset er net or kin g tdev echn olog ies in LAN/ env ir eonm ent . Discard ( DE) by w t he DTE ice, such ast oa arou t er ,WAN t o ind icat t h at t he Com plet e wm it harnew an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, ked fr am e is of lesser imp or t ance r elat iv e t o ot her fr am es being t r ansmit t ed . and speed, Fram t h is book is aarcom e an p- t o- d at e r ef er ence o be t he discar t op icsded t hatbefor are eessen t o all es t h at e m plet ar ked asd "udiscard eligible" shoutld ot h ert ial fr am es net w or kin g in p rof essionals, r egar dless of ex pert ise. a congest ed n et wor k . Th is allow s f or a basic pr iorit izat ion m echan ism in Fr ame Relay net w or ks. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dwDar pr ot ocols, sersu v ices ed- .layer Fu ndam entEach al t ech nology ion pr ov a te,a— Cont ainsand en cap lat edinvu olv pper dat a. fr am e in tinf hisorvmat ariab le-is lengt h ided f ield on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions includes a user dat a or pay load f ield t h at w ill v ary in lengt h u p t o 16 , 000 oct et s. This field t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ser v es t o t r an sp ort t he higher - layer p rot ocol packet ( PDU) t hr ou gh a Fr ame Relay n et wor k . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, m preovid g aSe mqu or eenr ealist pict es ur et he of tinhe n et w or k ing onm ent s is in w hich Fra Cheinck ce — ic Ensur t egrealr it y wofortld r ansmit t ed daten a. vir This v alue pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr com put ed by t h e sour ce device and v er ified by t h e r eceiver t o en su r e int egr it y of ease pr odutct iv it y ission. an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient r ansm decisions for t h eir net w ork s.

LMI Frame Format Fram e Relay f r ames t h at conf or m t o t he LMI specif icat ions con sist of t he f ields illust r at ed in

Figur e 10 - 5. The f ollow in g d escr ipt ions sum m ar ize t he f ield s illu st r at ed in Figur e 10 - 5. Fla g— Delim it s t h e beginn in g and en d of t he fr am e.

• •

LM I D LCI — I d en t ifies t he f r ame as an LMI f r ame in st ead of a basic Fr am e Relay fr am e. of Content The LMITable - specif ic DLCIs valu e defined in t he LMI consort iu m specif icat ion is DLCI = 102 3. I ndex

d I nf orm i on I, ndi or — I nt e rn U et nnum w or k ingbe Tere chnologie s H aat ndbook Fourca th tEdit ionSet s

t he poll/ f inal b it t o zer o.

By Cisco Systems, Inc.

P rot ocol Di scr im in at or — Alw ay s cont ains a v alue ind icat ing t h at t h e fr am e is an LMI fr am e.

Pub lish er: Cisco Press Pub Cal Datl e:Re Sep fetem re ber nce— 1 1, 2Alw 003 ay s

cont ains zer os. This field cur r en t ly is not used f or any pur pose.

I SBN: 1- 58 705 -1 19 -2

Me ssa ge Ty pe— Labels t he fr am e as one of t he f ollow ing m essage t yp es: Pages: 11 28 - St a t us- i nqu ir y m essage — Allow s a user device t o inqu ir e ab out t he st at us of t he net w or k. - St a t us m e ssa ge — Resp onds t o st at us- inq uir y messages. St at us m essag es in clud e The u pdat edk eepaliv edit iones of and t he PVC b est -stselling in- one net w ork ing r ef erence p rov ides cover age of at u s mallessages. essent ial an d cu t t ing- edg e t ech nologies. I nf orm a t ion Ele m en t s— Cont ains a v ar iab le num b er of in divid ual inf or mat ion elem ent s Con ovcon er v sist iew sofoft he t echn ologing iesfields: essen t ial t o n et wor k ing pr ofession als at all lev els, f rom ( I Es)cise . I Es follow nov ice t o ex pert . - I E I den t if ie r— Un iq uely ident ifies t he I E. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP - I E Len gt h— I n dicat es t he lengt h of t h e I E. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age - D a t a— Consist s of 1 or m ore by t es con t aining en capsulat ed u pper - layer d at a. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Fra m e Che ck Se qu en ce ( FCS) — Ensur es t he in t eg r it y of t r ansmit t ed dat a. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary Fram e Relay is a net w or king p rot ocol t hat wor k s at t he b ot t om t w o lev els of t he OSI refer ence m odel: t h e phy sical and dat a lin k layer s. I t is an exam p le of packet - sw it ch ing t ech nology , w hich enables end st at ions t o dy nam ically shar e n et w or k r esou rces. •

Table of Content s

• Fram e Relay Idndex ev ices f all int o t he f ollow in g t wo gener al cat egor ies: I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Dat a t erm inal eq uipm ent ( DTEs) , w hich include t er m inals, person al comp ut er s, rou t er s, and br idg es

Pub lish er: Cisco Press Pub Dat Datae:cir Sep cuit tem-ber t er1m 1,in 2 003 at ing

equipm ent ( DCEs) , w hich t r ansm it t he dat a t hr oug h t he n et w or k and ar1e 58 of705 t en-1car I SBN: 19 -2rier - ow ned d ev ices ( alt houg h, incr easing ly , ent er pr ises are b uy ing t heir ow n DCEs Pages: 11 28 and imp lem ent ing t h em in t h eir n et wor k s)

Fram e Relay n et w or k s t r ansfer d at a u sing on e of t he f ollow ing t w o con nect ion t y pes: Sw it ched v ir t ual cir cu it s ( SVCs) , w hich ar e t emp orar y conn ect ions t hat are cr eat ed f or each The udat pdat a ed t r ansfer edit ionanof d t he h enb est ar e- selling t er m in at alledinwone h en net t hewdat orkaing t ran r efsference er is comp p rovlet ides e ( not cover a age w idely of essentused ial ancon d cu nect t t ingion )edg e t ech nologies. Perm an en t v irt ual cir cu it s ( PVCs) , w hich are perm anent connect ions Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The Dnov LCIice is at ovex alue pert assig . ned t o each v ir t ual cir cu it and D TE d ev ice con nect ion p oin t in t he Fr am e Relay WAN. Tw o diff er ent con nect ion s can be assig ned t he sam e valu e w it hin t he sam e Fr am e chapt eron s include cov of erag por t antect t opics RelayNew WAN—one each side t hee vofirtim ual conn ion. like VoI P and EAP Cov of st cut t ing edge t echn, ologies opt ical ,nand et wor k ing st m oren age I n 199 0, erag Ciscoe Sy em s, St r at aCom Nor t h erlik n eTelecom Digit al and Equ ip t Cor por at ion dev elop ed a set of Fr am e Relay en hancem en t s called t he Local Manag em ent I nt erf ace ( LMI ) . The Aut h ored en byt sCisco ems, or ldw leader or king f or t he Ifnort ermnanagin et . LMI en hancem off er Sy a st n um berwof featide u res ( r eferin rednet t owas ex t ensions) g com plex int er net w ork s, includ in g t he f ollow ing : I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Global addr essing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet Vir teual w itcir h cu new it st anatdus u pdat messages ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Mu lt icast ing net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: •

What k ind of t echn ology is Fr ame Relay ? Table of Content s

I ndex Nam e t he t wo k in ds of p ack et - swit chin g t echn iq ues discussed in t his chapt er , and I nt e rn et w or k br ingiefly Te chnologie s H each. a ndbook , Four th Edit ion describe •

2:

By Cisco Systems, Inc.

3:

Descr ibe t he dif fer en ce b et ween SVCs and PVCs.

Pub lish er: Cisco Press

4:

What is t h e dat a- link conn ect ion ident ifier ( D LCI ) ?

Pub Dat e: Sep tem ber 1 1, 2 003 I5SBN: 1- 58 705 -1 19 : Descr ibe h -2 ow

LMI Fram e Relay d if fer s f rom basic Fr am e Relay .

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 11. High-Speed Serial Interface Obj e ct i ve s • •

Table of Content s

Discuss t he h ist or y an d st an dar ds of HSSI . I ndex

I nt e rn Ex et wplain or k ingt he Te chnologie s Hspecificat a ndbook , Four ion . t echn ical ionsthofEdit HSSI By Cisco Systems, Inc.

Descr ibe t he benef it s of em ploy ing HSSI t echnology . Pub lish er: Cisco Press

Discuss how HSSI operat es.

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction The High - Speed Ser ial I nt er face ( HSSI ) is a DTE/ DCE int er face t hat w as dev elop ed by Cisco Sy st em s and T3 plus Net w or king t o add ress t he n eed for high- sp eed com m un icat ion ov er WAN link s. The HSSI specificat ion is av ailable t o any or gan izat ion w ant in g t o im plement HSSI . •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

HSSI Interface Basics HSSI def in es bot h elect r ical and phy sical in t erf aces on DTE an d D CE devices. I t oper at es at t h e ph ysical layer of t h e OSI r efer en ce mod el. • Table of act Content HSSI t echnical char er istsics are su mm ar ized in Table 1 1- 1. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Tab le 1 1 - 1 . HSSI Te chn ical Cha r act er i st ics

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

Cha raI SBN: ct e ri1-st 58ic 705 -1 19 -2

V a lue

Pages: 11 28 Max im um signaling r at e

52 Mb ps

Max im um cable lengt h

50 f eet

Num ber of conn ect or p oint s

50

I nt er face ed edit ion of t he b est - selling all- in- oneDTEDCE The u pdat net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ingedg e t ech nologies. Elect rical t echnolog y Dif ferent ial ECL Ty pical pow er consum pt ion 61 0 m W Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Topology Point - t o- point nov ice t o ex pert . Cab le t yp chapt e Shielded t wist edair wir e New er s include cov erag e of im por t ant t opics like VoI Ppand EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age The m ax im um signaling r at e of HSSI is 5 2 Mbps. At t his r at e, HSSI can hand le t he T3 speeds Aut h ored Sy st's ems, or ldwt echn ide leader in as netwwell or king f orOft he t eranneln et . 1 ( OC- 1 ) ( 45 Mb ps) of mby anyCisco of t oday f ast wWAN ologies, as t he ficeI nCh speed s ( 52 Mb ps) of t h e syn ch ron ous dig it al hier archy ( SDH) . I n addit ion, HSSI easily can Ipr n tov ern et w orhk in g Tech nologies t h such Ed it ion is aencom pr ehensive ide hig speed conn ect iv itHand y betbook w een, Four LANs, as ,Tok Ring an d Et herrefer net . ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. m s,cou con ceplogic t s, t echn ologies, d devices used t oday ' ses net w ork ing The u se of diffMast er enter ialt he emtitert erpled ( ECL) helps an HSSI ach iev e highindat a r at and low indu stlevels. ry . LearECL n how incoru por int er net or kin in t ofor a LAN/ ir onmied entby . noise h ast obeen sedatine Cray comwpu t er gsyt echn st em olog int eries faces y ear WAN s and env is specif plet e Hig w it hh new anmdance u pdat edallel chapt on secur it y), com st or m age, options ical net w dar or k din fg, tCom he ANSI Per for Par I nter ersface ( HI PPI unicat st an or scalabilit y, and speed, t her is LAN bookcom is amcom pletion e an u p-ist oershelf ence ttechn o t heology t op ics t hat are t ial t o all super comp ut un icat s. dECL and at offe- rt ef het hat per m itessen s ex cellent w or kinon g pt he rof essionals, r egaring dless ex pertt im ise.ing m arg ins. rnet et im ing receiv er, result in of reliable Reader s w ill obtbm aininaiatgur reat un der an ding LAN and n etis w or ing, pt ar t icu ly35 the HSSI uses a su e, er FCCappst r oved 50-ofp in conn ectWAN or t hat smk aller han it lar s V. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov count er par t . To r ed uce t he n eed for male- m ale and fem ale- female ad apt er s, HSSI cab le ided on a b r oad or r ang egr sym st ale. em s The and HSSI serv ices, ailed descr s,srev quest connect s aree of spint ecif iedalas cableinuclud sesing t h edet sam e n um beriptofion pin andiew w ires asions t he tSm o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . all Com pu t er Syst em s I nt erf ace 2 ( SCSI - 2) cab le, b ut t he HSSI elect r ical specif icat ion is m or e Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy concise. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

HSSI Operation The f lex ibilit y of t h e HSSI clock an d d at a- sig naling pr ot ocol m ak es u ser ( or vend or) ban dw idt h allocat ion possible. The D CE con t r ols t he clock by chan ging it s speed or b y delet in g clock pu lses. I n t his w ay , t he D CE can allocat e ban dw idt h bet w een app licat ions. For ex amp le, a PBX m ay •r eq uir e a p art Table of Content s of b andw idt h, a rou t er anot h er am ou nt , an d a chann el ex t ender a icular am ou nt •t hir d am ountI.ndex Bandw idt h allocat ion is k ey t o mak ing T3 and ot her b road band serv ices af for dab le Iand nt e rn et wular or k ing pop . Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

HSSI assum es a peer- t o- peer in t elligence in t he DCE and DTE. The cont r ol pr ot ocol is sim p lif ied , w it h just t w o cont r ol sign als requ ired ( " DTE av ailab le" and " DCE av ailable" ) . Bot h sig nals m ust Pub lish er: Cisco Press be assert ed befor e t h e dat a cir cuit can b ecom e v alid . The D CE and DTE ar e ex pect ed t o be Pub Dat e: Sep tem ber 1 1, 2 003 capable of m anag ing t he n et w or k s behind t h eir in t er f aces. Redu cin g t h e nu mb er of con t rol 58es 705cir -1 19 -2 r eliab ilit y by r ed ucing t he n um ber of circuit s t hat can f ail. signalsI SBN: im pr1-ov cuit Pages: 11 28

Loopback Tests HSSI pr ov ides fou r loopback t est s, w hich ar e illust r at ed in Figur e 11 - 1. Th e fir st pr ov ides a local The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of cable t est as t h e signal loop s back af t er it r eaches t h e DTE por t . Th e second t est r each es t he line essent ial an d cu t t ing- edg e t ech nologies. por t of t he local DCE. Th e t hir d t est reaches t he lin e por t of t he r em ot e DCE. Fin ally , t h e fou rt h t est is a DCE- in it iat ed t est of t h e DTE' s DCE p ort . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

r e 1 1cov -1erag . H eSSI Su s Four Loopba ck Te st s New chaptFigu er s include of im porppor t ant ttopics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary HSSI is an int er face t echnology t hat was developed by Cisco Sy st em s an d T3 plus Net w or kin g in t he lat e 199 0s t o fill t h e need f or a high- speed dat a com m un icat ion solu t ion ov er WAN lin ks. I t uses dif ferent ial em it t er - coupled log ic ( ECL) , w hich pr ovid es h igh- speed dat a t ran sf er w it h low •noise levels. Table Content s HSSIofpin connect ors are sign ificant ly sm aller t h an p in conn ect or s f or comp et in g •t echnologies.I ndex The HSSI cable u ses t h e same num ber of p in s and w ir es as t he Sm all Com p ut er ISy nt st e rn et w k ing Te chnologie s H- a2) ndbook , Four ion r ical specif icat ion is m or e con cise. HSSI m ak es em s or I nt er face 2 ( SCSI cable, butthitEdit s elect ban dw idt h r esour ces easy t o allocat e, m ak ing T3 and ot her br oad band ser v ices av ailable and By Cisco Systems, Inc. aff or dable. HSSI r equir es t he p resence of only t w o con t rol sig nals, m aking it highly r eliable because t her e ar e few er cir cuit s t h at can fail. HSSI p er f orm s f our loop back t est s for r eliabilit y . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

Nam e at least t h r ee b en ef it s of im plem ent in g HSSI t echn olog y in a net w or k.

2:

I ndexe t he f our loop back t est s t hat HSSI per for m s. Nam

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 12. Integrated Services Digital Network • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ex plain w hat I SD N is.

By Cisco Systems, Inc.

Descr ibe I SDN devices and how t hey oper at e. Pub lish er: Cisco Press

Descr t heber specif Pub Dat e: ibe Sep tem 1 1, 2 icat 003 ion s

for I SD N dat a t r ansm it t al for t he t h ree lay ers at w hich I SD N

t rIansm s.705 -1 19 -2 SBN: 1-it58 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction I n t egrat ed Serv ices Digit al Net w or k ( I SDN) is com pr ised of dig it al t elep hony an d d at a- t r anspor t ser v ices of fer ed by region al t elep hone car r ier s. I SDN inv olv es t he dig it izat ion of t h e t eleph one net w or k, w hich p er m it s v oice, d at a, t ext , gr aph ics, m usic, vid eo, and ot her sour ce m at er ial t o be •t r ansm it t ed ov Table of Content er exist ing tselep hone w ir es. Th e emer gence of I SDN r epr esent s an ef for t t o •st andar d ize su I ndex bscr iber serv ices, u ser / net w or k int er faces, an d net w ork an d in t ern et w or k Icapabilit nt e rn et w ies. or k ing Te chnologie s Hions a ndbook , Four th Edit ion I SDN app licat in clud e high - speed im age app licat ions ( su ch as Grou p I V facsim , ad ditInc. ional t elephon e lin es in h omes t o ser v e t he t elecomm ut in g in dust r y , high - speed By Ciscoile) Systems, file t r an sf er , an d videoconf er encing. Voice serv ice is also an applicat ion f or I SDN. Th is ch apt er sumPub m lish arizes t h e und er ly ing t echn ologies and ser v ices associat ed w it h I SDN. er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ISDN Devices I SDN d ev ices in clu de t er min als, t er m inal ad apt ers ( TAs) , net w ork - t er m in at ion devices, linet er min at ion equ ip m en t , and exchan ge- t erm inat ion equip ment . I SDN t er m in als com e in t w o t y pes. Specialized I SDN t erm inals ar e r efer red t o as t erm inal eq uipm ent t yp e 1 ( TE1) . Non- I SDN •t er min als, such Table Content s pr edat e t h e I SDN st and ar ds ar e r ef err ed t o as t er m inal equ ip m en t asofDTE, t hat •t y pe 2 ( TE2 ) .I ndex TE1 s connect t o t he I SD N net w or k t hr oug h a fou r - wir e, t w ist ed - pair d ig it al link . ITE2 nt e rn w or k ingt Te a ndbook th Edit s et connect o tchnologie he I SDNs Hnet w or k ,tFour hr oug h a ion TA. The I SDN TA can be eit her a st andalone d ev ice or Cisco a boar d in sidInc. e t he TE2. I f t he TE2 is imp lem ent ed as a st an dalone dev ice, it connect s t o t he By Systems, TA v ia a st andar d ph ysical- lay er int er face. Ex am ples in clu de EI A/ TI A- 23 2- C ( for m erly RS- 232 C) , Pub V.2lish 4,er: anCisco d V.Press 3 5. Pub Dat e: Sep tem ber 1 1, 2 003 Beyon d t he TE1 and TE2 d ev ices, t h e nex t conn ect ion point in t he I SDN n et wor k is t h e net w or k SBN: 7051-1(19 -2 ) or n et wor k t er m inat ion t yp e 2 ( NT2) device. These are net w ork t er min Iat ion 1-t y58pe NT1 t er minPages: at ion 11 d 28 ev ices t hat conn ect t he f our - w ir e su bscr iber w ir ing t o t h e conv en t ional t w o- w ir e local loop. I n Nor t h Am er ica, t he NT1 is a cust om er pr em ises equipm ent ( CPE) dev ice. I n m ost ot her p art s of t he w or ld, t he NT1 is par t of t he net w or k pr ov ided b y t he car r ier . Th e NT2 is a m or e com p licat ed device t hat t y pically is foun d in dig it al pr ivat e br anch ex chang es ( PBXs) and t hat per for m s Lay er 2 and 3 pr ot ocol fu nct ions an d concent r at ion ser v ices. An NT1/ 2 device also exist as aed sinedit gleion devof icet he t hat com bin es allt heinf unct ofork aning NT1 an NT2. The uspdat b est - selling oneions net w r efand erence p rov ides cover age of

essent ial an d cu t t ing- edg e t ech nologies. I SDN specifies a n um ber of r ef erence p oin t s t hat def in e logical int er faces bet w een fu nct ional gr oup s, su ch as TAs and NT1s. I SDN r efer en ce point s in clud e t he follow in g: Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . R— The r eference p oin t b et ween non- I SDN eq uipm ent and a TA. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP S— The r eference p oin t b et ween user t er m inals and t h e NT2. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age T— The r eference p oin t b et ween NT1 an d NT2 dev ices. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . U — The r eference p oin t b et ween NT1 d ev ices an d lin e- t er m in at ion eq uipm ent in t h e car r ier orkk.in g The U rnologies efer en ceHand pointbook is relevan in Nor Am er w hererefer t he ence NT1 fu nct ion is I n t ernnet et wwor Tech , Four t th on Edlyit ion , is tah com prica, ehensive t hat not pr ov ided b y t he car r ier n et wor k . enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Figur - 1 illust r at es sampor pleatI SDN con figu ion s t hin r ee icesWAN at t ach edir tonm o anent . indu stery12 . Lear n how t o aincor e int er net w orrat kin g tand echnshow olog ies t o da ev LAN/ env ICom SDNplet sweit ch at t he cent r al off ice. Tw o of t h ese d ev ices ar e I SDNcom pat ible, so t hey can b e y, w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit at t ached t hr oug h an S ref er ence point t o NT2 d ev ices. Th e t hir d device ( a st an dar d, n onI SDN and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all tnet elep hone) at t ach es t hr oug h t h e r ef erence poin t t o a TA. Any of t hese dev ices also could at t ach w or kin g p rof essionals, r egar dless of ex pert ise. t o an NT1 / 2 device, w hich w ould r eplace bot h t he NT1 and t h e NT2. I n add it ion , alt hou gh t hey ar e not sshow n, sim usererstun at ion at t ached t o and t h e WAN far - r ight sw itpch. Reader w ill obt ain ilar a g reat dersstar aneding of LAN n et wI SDN or k ing, ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Figu r ealso 1 2 ext -1 end . Sam I SDN Conf ig ur a t ion I llt s, ust r aalso t e st oRe onshi ps Cov erag e is ed npl ot eonly t o new n et wor k ing concep but oldla ert,i legacy ee nicDe s tan Ref e rlden ce s vir onm ent s in w hich syst em s, pr ovid in g a mBe or et w r ealist pictvi urce e of he d realw or n et w orPoin k ing ten pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Services Ther e ar e t w o t y pes of serv ices associat ed w it h I SDN:

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BRI

Table of Content s I ndex

I nt e rn PRI et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

ISDN BRI Service Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

The I SDN Rat nt er face ( BRI ) ser v ice of fer s t w o B chann els an d on e D ch annel ( 2 B+ D ) . I SBN:Basic 1- 58 705 -1 e 19I-2 BRI B- ch annel serv ice oper at es at 64 k bp s and is m ean t t o carr y u ser d at a; BRI D- chann el Pages: 11 28 ser v ice operat es at 16 k bps and is m ean t t o car r y cont r ol an d sign alin g in for m at ion, alt h ough it can su ppor t user dat a t ran sm ission un der cer t ain cir cum st ances. The D channel sign alin g pr ot ocol com pr ises Layer s 1 t hr oug h 3 of t h e OSI r efer en ce m od el. BRI also pr ov id es for f r amin g cont r ol an d ot h er over head, b r in ging it s t ot al bit r at e t o 19 2 kb ps. The BRI phy sical layer specif icat ion is I nt er nat ional Telecomm u nicat ion Union– Telecom m un icat ion s St andar d s Sect ion The pdat ed edit t he b est selling r efTelegr erenceaph p rov ides cover age of ( I TU-u T) ( f orm er lyion t heofConsult at-ive Comallm itint eeone f or net I ntw erork nating ional and Telep hone essent ial an d cu t t ingedg e t ech nologies. [ CCI TT] ) I . 430 . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

ISDNnovPRI Service ice t o ex pert .

er e s include cov erag ofv ice im por t ant t opics VoI and P and EAP I SDN New Pr imchapt ar y Rat I nt er face ( PRI ) eser of fer s 23 B ch like annels 1 D ch annel in Nor t h Am er ica an d Jap an, y ield ing a t ot al bit r at e of 1 . 544 Mb ps ( t h e PRI D chann el ru ns at 64 k bps) . e of cut Aust t ing redge echnotologies ical n et k ing and age els plus on e 64I SDN Cov PRIerag in Eur ope, alia, tand h er parlik t seofopt t he w or ldwor pr ov id es 30 st Bor chann k bps D chan nel and a t ot al int er face r at e of 2. 0 48 Mbp s. The PRI phy sical lay er specif icat ion is Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I TU- T I .4 31. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ISDN Specifications This sect ion d escrib es t he v ar iou s I SDN specificat ions f or Lay er 1, Layer 2 , and Lay er 3.

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Layer 1 •

Table of Content s I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

I SDN p hy sical lay er ( Lay er 1) fr am e for m at s d if fer d ep en ding on w het her t he f r am e is out bou nd By Cisco Systems, Inc. ( f rom t er m inal t o net w or k) or inb ound ( f r om net w or k t o t er m inal) . Bot h ph ysical layer int er faces ar e show n in Figur e 12 - 2. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

FiguPages: r e 111228-2 . I SD N Ph y si cal Lay er Fr a m e For m a t s D if fe r D ep en din g on The ir Di r ect ion

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy The f r am es ar e 4 8 b it s long, of w hich 3 6 b it s r ep resen t d at a. The bit s of an I SD N ph ysical lay er syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich fr am e ar e used as follow s: pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t ides h eir syn net w ork s. ion F— Prov chr onizat L— Adju st s t he av erag e bit valu e E— Ensur es cont ent ion r esolut ion w hen sev er al t er m inals on a p assiv e bus con t en d for a chann el

A— Act iv at es dev ices S— I s unassig ned B1 , B2 , an d D — Handle user dat a Mu lt ip le I SD N user dev ices can be ph ysically at t ach ed t o one cir cu it . I n t his conf ig ur at ion, collisions can r esult if t w o t er min als t ran smit sim ult an eou sly . Th er efor e, I SDN p rov ides f eat u res • Table of Content s t o det er m ine link cont en t ion. Wh en an NT r eceiv es a D bit f r om t he TE, it echoes b ack t he bit in • I ndex t he next E- b it posit ion. Th e TE ex pect s t h e next E bit t o b e t he sam e as it s last t ran sm it t ed D b it . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Term By Cisco inals Systems, cann ot Inc.t ran sm it in t o t h e D ch annel u nless t hey fir st det ect a sp ecific n um ber of ones ( ind icat ing " n o signal" ) cor r esp ondin g t o a p re- est ablish ed p rior it y . I f t he TE det ect s a b it in t he ech Pub o ( lish E) er: chan nelPress t hat is dif ferent f rom it s D b it s, it m ust st op t r ansm it t ing im mediat ely . This Cisco simp le t ech nique ensu res t h at on ly one t er min al can t r an sm it it s D m essag e at on e t im e. Aft er Pub Dat e: Sep tem ber 1 1, 2 003 successful D- m essage t ran sm ission , t he t er m inal h as it s pr ior it y r ed uced by requ ir ing it t o d et ect I SBN: 1- 58 705 -1 19 -2 m or e con t inuou s ones bef ore t ran sm it t ing . Term inals can not r aise t heir pr ior it y un t il all ot her Pages: 11 28 dev ices on t he sam e line h ave had an op por t un it y t o send a D m essage. Telep hone con nect ion s hav e hig her pr ior it y t han all ot h er ser vices, and sig naling in for m at ion has a higher p rior it y t h an non sig naling in for m at ion.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Layer 2 essent ial an d cu t t ing- edg e t ech nologies. Lay er 2 of t he I SDN sig naling pr ot ocol is Link Access Procedur e, D chann el ( LAPD) . LAPD is similar t ocise Higha tLink ol (essen HD LC) Access Procedur Balanced ( see Con ovLev er v el iewDat s of echnCont ologries t ialand t o nLink et wor k ing pr ofessione,als at all lev( LAPB) els, f rom Ch aptnov er 16 nchr s Dat a Link Cont r ol an d D er iv at ives," and Ch apt er 17 , " X. 25 , " f or m ore ice, t"oSyex pertonou . inf orm at ion on t hese pr ot ocols) . As t he ex pansion of t he LAPD acr ony m ind icat es, t his lay er is chapt include erag imcon porttrol ant and t opics like VoIinf P orm and at EAP used New acr oss t he er D schan nel tcov o en su ree tof hat sig naling ion flow s an d is r eceiv ed pr oper ly. The LAPD f ram e f or mat ( see Figur e 12 - 3) is ver y sim ilar t o t hat of HDLC; like HDLC, erag e ofvisor cut ty, inginfor edge t echn e opt icalfrnam et wor ing LAPD and stpr orot age LAPD Cov uses super m at ion, ologies an d unnlik um bered es. kThe ocol is f or mally specif ied in I TU- T Q. 920 and I TU- T Q. 9 21. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Figu r e 1 2 -3 . LAPD Fr a m e For m a t I s Sim il ar t o Th a t of H DLC a n d LAPB t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

The LAPD Flag and Con t rol fields ar e ident ical t o t hose of HDLC. The LAPD Addr ess field can be eit her 1 or 2 by t es long. I f t h e ex t end ed add ress bit of t he f irst by t e is set , t he addr ess is 1 b yt e; if it is n ot set , t he addr ess is 2 b yt es. Th e fir st Add ress- field b yt e con t ains t h e ser v ice access point ident if ier ( SAPI ) , wh ich ident if ies t he por t al at w hich LAPD ser v ices ar e pr ov ided t o Lay er 3. The C/ R b it indicat es w het her t h e fr am e cont ains a com man d or a r esp onse. The Ter min al En dpoint I dent if ier ( TEI ) f ield ident ifies eit her a sing le t er m inal or mu lt iple t erm inals. A TEI of all ones ind icat es a br oadcast . •

Table of Content s

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I ndex

I nt e rn et w3 Layer or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Tw o Layer 3 specif icat ion s ar e used f or I SDN sign alin g: I TU- T ( for m er ly CCI TT) I .4 50 ( also k now aser:I TUT Press Q. 930 ) an d I TU- T I . 45 1 ( also kn own as I TU- T Q.9 31) . Toget her , t hese pr ot ocols Pubnlish Cisco supp ort user - t o- user, cir cuit - sw it ch ed , and pack et - sw it ched con nect ion s. A v ar iet y of callPub Dat e: Sep tem ber 1 1, 2 003 est ablish ment , call- t er m in at ion, inf or m at ion , and m iscellaneous m essages ar e specif ied , I SBN: 1- 58 705 -1 19 -2 includin g SETUP, CONNECT, RELEASE, USER I NFORMATI ON, CANCEL, STATUS, and Pages: 11 28Th ese m essages ar e f unct ionally similar t o t hose p rov ided by t h e X. 25 pr ot ocol DI SCONNECT. ( see Ch apt er 17 f or m or e inf orm at ion) . Figur e 12 - 4, f r om I TU- T I . 4 51, sh ows t he t y pical st ages of an I SD N circuit - sw it ched call.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent Figu ial ran e d1cu 2 t-4 t ing. An edg IeSDN t ech nologies. Cir cu it -Sw it che d Cal l M ove s Thr ou gh Var i ous

St ag es t o I t s De st in at ion Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

•

Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary I SDN is com pr ised of digit al t eleph ony an d d at a- t r anspor t ser vices off er ed by r egional t elephon e carr ier s. I SDN inv olves t h e digit izat ion of t he t elephon e net w or k t o t r an sm it v oice, dat a, t ex t , gr aph ics, m usic, v id eo, and ot her sour ce m at erial ov er exist ing t elep hone w ir es. •

Table of Content s

I• SDN d ev icesI ndex in clu de t he follow in g: I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Term inals

PubTerm lish er:inal Ciscoadapt Press er s

( TAs)

Pub Dat e: Sep tem ber 1 1, 2 003

Net w ork - t705 er min I SBN: 1- 58 -1 19at -2 ion d ev ices Pages: 11 28

Lin e- t er m in at ion eq uipm ent Ex chang e- t er m inat ion eq uipm ent The I SDN specif icat ion r ef erences specif ic con nect ion p oin t s t hat def in e logical int er faces bet Thewueen pdatdev ed ices. edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. I SDN u ses t h e follow ing t w o t y pes of serv ices: Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Basic er face ( BRI , w hich of fer s t w o B ch annels and on e D chan nel ( 2 B+ D ) nov iceRat t o eexI nt pert . Pr imar y Rat nt er facecov ( PRI ) , ew of h ich 23t opics B chann anPdand 1 D EAP chann el in Nor t h Am er ica New chapt eres Iinclude erag imoff porers t ant likeels VoI and Jap an, and 3 0 B channels an d 1 D chann el in Eu r ope and Aust r alia Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age I SDN r un s on t he b ot t om t h ree lay er s of t h e OSI r efer en ce mod el, and each layer u ses a dif fer en ion t o Sy t r ansm it dat Autt hspecif ored icat by Cisco st ems, w ora. ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

Which r ef er ence poin t f or I SDN logical d ev ices is r elev ant only in Nor t h Am er ica?

2:

I ndex ar e t he t w o speed s of I SDN PRI ser v ices? What

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : Of tInc. h e 48 By Cisco Systems,

bit s in t he I SD N ph ysical layer f r ame for m at s, how m an y bit s r epr esent

dat a? Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 13. Point-to-Point Protocol Obj e ct i ve s • •

Table of Content s

Descr ibe t he dev elop ment of PPP. I ndex

I nt e rn Descr et w or kibe ing Te chnologie s H a ndbook , Four th Edit iont hey t he com ponent s of PPP and how

oper at e.

By Cisco Systems, Inc.

Pr ovid e a sum m ar y of t he b asic p r ot ocol elem en t s and oper at ions of PPP. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction The Point - t o- Point Prot ocol ( PPP) or igin ally em erg ed as an encapsulat ion pr ot ocol f or t r anspor t ing I P t r af fic ov er point - t o- point lin ks. PPP also est ab lish ed a st an dar d for t h e assig nm en t an d m an agement of I P add r esses, asy nchr onou s ( st art / st op ) an d b it - or ient ed •syn ch r onous Table of Content encapsulat ions, net w or k pr ot ocol m ult iplexin g, link conf igur at ion, lin k qualit y •t est in g, er r orI ndex det ect ion , and opt ion negot iat ion f or such capab ilit ies as n et w or k lay er addr ess Inegot nt e rn et or k ing chnologie a ndbook ,negot Four thiat Edit iatwion andTedat a- coms pH ression ionion . PPP sup por t s t h ese f unct ions b y pr ov iding an extCisco ensible Link Con By Systems, Inc. t r ol Pr ot ocol ( LCP) and a fam ily of Net w or k Cont r ol Pr ot ocols ( NCPs) t o negot iat e opt ional con figur at ion par am et er s an d f acilit ies. I n ad dit ion t o I P, PPP su ppor t s ot her pr otPub ocols, inclu ding Nov ell' s I nt ern et wor k Pack et Ex chang e ( I PX) an d D ECnet . lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

PPP Components PPP p r ovides a m et h od f or t r ansm it t ing dat ag ram s ov er ser ial p oint - t o- p oin t link s. PPP con t ains t hr ee m ain com pon en t s: •

Table of Content s

A m et hod f or encapsulat ing dat ag ram s ov er ser ial link s. PPP u ses t he High- Level Dat a Lin k I ndex t rol p rotsocol as a ,basis ing dat ag ram s ov er poin t - t o- point link s. I nt e rn Con et w or k ing( HDLC) Te chnologie H a ndbook Four thf or Editencapsulat ion ( See Ch apt er 16 , " Sy nchr onou s Dat a Link Cont r ol an d D er iv at ives," for m ore in for m at ion By Cisco Systems, Inc. on HDLC.) •

PubAn lish ex er: t Cisco PressLCP ensible

t o est ab lish, con figu re, an d t est t he d at a link conn ect ion.

Pub Dat e: Sep tem ber 1 1, 2 003

AI SBN: f am ily NCPs 1- 58of 705 -1 19 -2for est ablishing and conf igur ing dif fer en t net w or k lay er pr ot ocols. PPP is designed t o allow t h e sim u lt aneous use of m ult iple n et wor k lay er pr ot ocols. Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

General Operation To est ablish com m unicat ions over a point - t o- p oint lin k, t he or iginat ing PPP fir st sends LCP fr am es t o con figu re an d ( opt ionally ) t est t h e dat a lin k. Aft er t h e link has been est ablish ed and opt ion al facilit ies h ave been negot iat ed as n eeded by t h e LCP, t he or iginat in g PPP sen ds NCP •fr am es t o ch oose Table an of Content s re on e or m or e net w or k layer p rot ocols. When each of t h e ch osen d con figu •net w or k layerI ndex p rot ocols h as been conf igur ed, p ack et s f rom each net w or k layer pr ot ocol can be Isen nt e trnov et w ing lin Te k. chnologie s Ha Fourconfig th Edit ion erortkhe Th e link wndbook ill r em, ain ur ed f or comm un icat ion s unt il ex plicit LCP or NCP fr am es Systems, close t h eInc. link , or un t il som e ex t er nal ev en t occur s ( f or ex am ple, an inact ivit y t im er By Cisco exp ires or a user int er venes) . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Physical Layer Requirements PPP is cap able of oper at ing acr oss any DTE/ DCE in t er f ace. Exam p les includ e EI A/ TI A- 232 - C ( f orm er ly RS- 23 2- C) , EI A/ TI A- 4 22 ( for m erly RS- 422 ) , EI A/ TI A- 42 3 ( for m er ly RS- 4 23) , and I nt er nat ional Telecom m un icat ion Union Telecomm un icat ion St and ar dizat ion Sect or ( I TU- T) •( f orm er ly CCITable of 3 Content TT) V. 5. Thes only absolut e r equir em en t im posed b y PPP is t h e pr ov ision of a •du plex cir cuitI ndex , eit her dedicat ed or swit ched, t hat can op er at e in eit her an asy nchr onou s or Isyn nt e ch rn et w or k ingb Te H a ndbook , Four th Edit ion lin k layer f r ames. PPP does not imp ose any r onous it -chnologie ser ial m sode, t r anspar ent t o PPP r est r ict ions r egar ding t r ansm ission rat e ot her t han t h ose im posed by t h e par t icu lar DTE/ DCE By Cisco Systems, Inc. int er face in use. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

PPP Link Layer PPP u ses t he pr inciples, t er m inology , an d f r ame st r u ct u re of t he I nt er nat ional Or ganizat ion for St and ard izat ion ( I SO) HDLC p rocedur es ( I SO 330 9- 19 79) , as m odified by I SO 33 09: 1 984 / PDAD1 " Add en dum 1: St art / St op Tr ansm ission. " I SO 3 309- 197 9 specifies t he HD LC •fr am e st r uct ur Table of use Content s nch ron ous env iron m en t s. I SO 33 09: 1 984 / PDAD1 specif ies pr oposed e f or in sy •m odificat ionsI ndex t o I SO 3309 - 19 79 t o allow it s u se in asy nchr onous en vir onm ent s. The PPP cont r ol Ipr ntoced e rn etur w or s ions H a ndbook Fourt rtholEdit ion en cod in gs st and ard ized in I SO 4 335 - 197 9 an d esk ing useTet chnologie he definit and , con field I SO 4 335 - 197 9/Inc. Add en dum 1- 19 79. The PPP fr am e for m at ap pear s in Figur e 13 - 1. By Cisco Systems, Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Figu r e 1 3 -1 . Six Fie lds M a k e Up t he PPP Fr a m e

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise er v iew s of sum t echn iest he essen t oenfet wor illust k ing rpr als eat13 all- 1: lev els, f rom The f ollow in g ov d escr ipt ions molog ar ize PPPt ial fr am ields atofession ed in Figur nov ice t o ex pert . Newg— chapt er s include cov erag e of porb teg ant t opics EAPTh e flag f ield con sist s Fla A single b yt e t hat in dicat esim t he in ning orlike endVoI of P a and f r ame. of t he binar y seq uence 01 1111 10. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Ad dre ss— A single b yt e t hat con t ains t h e binar y seq uence 11 111 111 , t he st an dar d Aut h ored by st ems, or ldw ide leader in alnet king f oresses. t he I n t er n et . br oadcast ad Cisco dr ess.Sy PPP doeswnot assign ind ividu stw ator ion addr I n t ernCont et w or k in nologies book , Four Ed ityion , isuence a com00 pr000 ehensive hat rol —g ATech single b yt e tHand hat con t ains t h et hbinar seq 011 , wrefer hich ence calls tfor enables net wission or kin gofp user r ofessionals o un anfrd am im plem en t cont em por ar orkilar ing t o t r ansm dat a in tan underst sequ and en ced e. A conn ect ionless linyk int sererv net ice w sim t echnologies. Mast t he Cont t er mrs,ol con cep Typ t s, teechn an. d( For devices t oday ' s net wLLC ork ing t hat of Log icalerLink ( LLC) 1 isologies, pr ovid ed m oreused in for in m at ion about indu stt yrypes . Lear at et ointCh er apt net er w or16 kin andn fhow ram et ot yincor pes,por r efer . ) g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book com pletident e anifdyutpd atocol e r efen er cap ence o ted he in t opt he ics int hat essen t ialoft ot he all P rot ocol— Two is byat es t hat het op rot sutlat for mare at ion f ield net w or kin g rof essionals, egar of ex fr am e.pThe m ost up- trodatdless e v alues ofpert t heise. p rot ocol field ar e specif ied in t he most recen t Assig ned Nu mb er s Req uest For Com m en t s ( RFC) . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dwDar pr ot ocols, and v ices inv olv . Fut hndam al t ech infocol or mat ion is prinovtided a te,a— Zer o or m oreser b yt es t hat coned t ain e datent ag ram fornology t he pr ot specified he on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions pr ot ocol f ield. The end of t he in for m at ion f ield is f ound by locat ing t h e closing f lag sequence t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . and allow ing 2 b yt es f or t h e FCS f ield. The def ault m ax imu m lengt h of t h e infor m at ion field Cov erag e 50 is 0also n otagr only t oent new n et woring k ing concep t s, ent butatalso olduse er , legacy is 1, by text es. end By ed pr ior eem , consent PPP im p lem ionst ocan ot h er values syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in w hich for t he m ax imu m inf orm at ion field leng t h. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr oduFra ct ivm it ye an chdeck im pr seov que e eff nce iciency, ( FCS)help — Norm ing t he allyr eader 16 bit sm(ake 2 b yt mor es)e. in Byt elligent p rior agr , cost eem- eff en icient t, decisions consen fort ing t h eirPPP netim w ork plem s. en t at ions can use a 3 2- bit ( 4- b yt e) FCS f or imp r oved er r or det ect ion . The LCP can negot iat e mod ificat ions t o t he st an dar d PPP fr am e st r uct ur e. Modif ied f ram es, how ev er , alw ay s w ill be clear ly d ist ing uishable f rom st andar d fr am es.

PPP Link-Control Protocol The PPP LCP pr ov ides a m et hod of est ablish in g, conf igur ing , m aint aining , and t er min at in g t he point - t o- point connect ion. LCP g oes t hr ough f our d ist inct phases. •First , link estTable of Content s con figu rat ion negot iat ion occur . Befor e any net w ork lay er ablishm ent and •dat ag r ams ( for I ndex ex amp le, I P) can b e exchan ged, LCP f irst m ust op en t he con nect ion and Inegot nt e rn et k ingfigu Te chnologie s H am a ndbook , Four th phase Edit ion is com plet e w hen a config ur at ioniatweorcon rat ion par et er s. Th is ackn ow ledg m en t f ram e h as been b ot h sent and r eceived. By Cisco Systems, Inc.

This is f ollowed by link qualit y det er m in at ion. LCP allow s an opt ion al link qu alit y det er m inat ion Pub lish er: Cisco Press ph ase follow in g t he link - est ab lishm ent and config ur at ion- negot iat ion ph ase. I n t his p hase, t he Sep bererm 1 1, ine 2 003wh et her t he link qualit y is suf ficien t t o br ing up net w or k layer link Pub is tDat este:ed t otemdet I SBN: 158 705 -1 19 -2 pr ot ocols. This ph ase is opt ional. LCP can delay t r ansm ission of net w ork lay er pr ot ocol inf ormPages: at ion 11 un 28t il t his p hase is comp let e. At t his poin t , net w or k layer p rot ocol con figu rat ion negot iat ion occur s. Aft er LCP h as finished t he link qu alit y det erm inat ion ph ase, n et w or k lay er pr ot ocols can b e con figu red sep arat ely b y t he app rop riat e NCP an d can be b rou ght up and t ak en dow n at any t ime. I f LCP closes t h e link , it inf orm s t he net w or k layer p rot ocols so t hat t hey can t ak e ap pr opr iat e act ion. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent an dt ercumt inat t ing-ion edgoccu e t ech Finally,iallink rs. nologies. LCP can t er min at e t he link at an y t ime. Th is usually is don e at t he requ est of a user bu t can happ en b ecause of a phy sical ev ent , such as t h e loss of car r ier or t he exCon pir at ionov oferan id leper iod tolog imeries . essen t ial t o n et wor k ing pr ofession als at all lev els, f rom cise v iew s of t echn nov ice t o ex pert . Thr ee classes of LCP fr am es ex ist . Lin k- est ablishm en t f r ames ar e u sed t o est ablish an d con figur e a link New . Linkchapt - t ermerinat ion fr am eserag ar e eused t ert ant minat e a link an dPlink aint enance f r ames ar e s include cov of imt opor t opics like, VoI and- mEAP used t o m anag e and debug a lin k. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age These fr am es ar e used t o accom plish t he w or k of each of t h e LCP phases. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary The Poin t - t o- Point Pr ot ocol ( PPP) or iginally em er g ed as an encapsulat ion pr ot ocol for t r anspor t ing I P t r af fic ov er point - t o- point lin ks. PPP also est ab lish ed a st an dar d for assigning and m anag in g I P addr esses, asyn ch ron ous an d b it - or ient ed syn ch r onous encapsulat ion , net w or k •pr ot ocol m ultTable Content iplexof ing, link scon figu rat ion , link qu alit y t est ing , er ror det ect ion, and opt ion •negot iat ion f or I ndex added net w or king capab ilit ies. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

PPP p r ovides a m et h od f or t r ansm it t ing dat ag ram s ov er ser ial p oint - t o- p oin t link s, w hich in clu de By Cisco Systems, Inc. t he follow in g t hr ee com pon en t s: Pub lish er: Cisco Press Pub e: hod Sep tem 1 1, 2 003 A Dat m et f orberencapsulat ing

dat ag ram s ov er ser ial link s

I SBN: 1- 58 705 -1 19 -2

An ex t11 ensible LCP t o est ab lish, con figu re, an d t est t he conn ect ion Pages: 28 A f am ily of NCPs for est ablishing and conf igur ing dif fer en t net w or k lay er pr ot ocols PPP is cap able of oper at ing acr oss any DTE/ DCE in t er f ace. PPP does not im pose any r est rict ion r eg ar ding t r ansm ission r at e ot her t han t h ose im posed by t he par t icu lar DTE/ D CE int erf ace in The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of use. essent ial an d cu t t ing- edg e t ech nologies. Six fields m ak e up t h e PPP f ram e. The PPP LCP p rov ides a met hod of est ablish ing, con figu ring , m aint aining , and t er min at ing t he p oin t - t o- p oin t conn ect ion. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What ar e t he main com ponent s of PPP?

2:

I ndex is t h e only absolut e p hy sical lay er r eq uir em ent im p osed by PPP? What

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : HowInc. m any By Cisco Systems, 4:

field s m ake up t he PPP fr am e, and w hat are t hey?

How m any phases does t he PPP LCP g o t hr ou gh, an d wh at ar e t h ey ?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 14. Switched Multimegabit Data Service • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Tell how SMDS w or k s, and descr ibe it s com pon en t s.

By Cisco Systems, Inc.

Descr ibe t he oper at ional element s of t he SMD S env iron m en t , and out line it s und er ly ing Pubpr lish Cisco Press oter: ocol. Pub Dat e: Sep tem ber 1 1, 2 003

Discuss r elat ed19t-2 echn ologies. I SBN: 1- 58 705 -1 Pages: 11 28

Discuss SMDS access classes and cell f orm at s.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction Sw it ch ed Mu lt im egabit Dat a Ser vice ( SMDS) is a high - speed , pack et - sw it ched, d at agr am - based WAN n et wor k ing t ech nology u sed for com m un icat ion ov er p ublic d at a n et w or k s ( PDNs) . SMD S can use fiber - or cop per- b ased m ed ia; it su ppor t s speeds of 1 .5 44 Mbp s ov er D igit al Sign al lev el •1 ( DS- 1) t r ansm Tableission of Content s ies, or 4 4. 736 Mb ps ov er Digit al Sig nal level 3 ( D S- 3) t ran sm ission facilit •facilit ies. I n add I ndex it ion , SMDS dat a unit s are lar ge en ough t o en cap su lat e en t ire I EEE 802 . 3, I EEE I80 nt 2. e rn5, et w Te chnologie s ed H a ndbook Four Edit( ion anordk ing Fiber Dist r ibut Dat a I, nt erfthace FDDI ) f r ames. This ch apt er sum m arizes t he oper at ional element By Cisco Systems, Inc. s of t he SMD S env iron ment and ou t lin es t he un der ly ing pr ot ocol. A discussion of r elat ed t ech nologies, su ch as D ist r ibu t ed Qu eu e Dual Bus ( D QDB) is also pr ovid ed . ThePub chlish apter:erCisco closes w it h discu ssions of SMDS access classes and cell for m at s. Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SMDS Network Components SMDS net w or ks con sist of sever al u nder ly ing dev ices t o pr ov id e high - sp eed dat a ser v ice. Th ese include cu st om er pr em ises equip ment ( CPE) , car rier equip ment , and t he sub scr iber net w or k int er face ( SNI ) . CPE is t er m in al equip ment t y pically own ed an d m aint ain ed by t he cust om er . CPE •includes end Table of Content dev ices, such sas t erm inals an d p er sonal com pu t er s, an d in t er m ediat e nod es, such •as r out er s, mI ndex odems, an d mu lt ip lex ers. I n t er m ediat e nod es, h ow ev er, som et im es ar e p rov ided Iby nt etrn w or k ingcarr Te chnologie H a ndbook Edit ion heet SMDS ier. Carsr ier equ ip ,mFour en tthgener ally con sist s of h igh- speed W AN sw it ch es t hat m ust conf or m t oInc. cer t ain net w ork equ ipm en t specificat ions, such as t hose out lined by Bell By Cisco Systems, Com m un icat ions Resear ch ( Bellcor e) . These specif icat ion s define net w ork operat ion s, t he int er face bet w een a local car r ier net w ork and a long - dist ance carr ier net w or k, and t he int er f ace Pub lish er: Cisco Press bet w een t w o sw it ches inside a sin gle carr ier net w or k. Pub Dat e: Sep tem ber 1 1, 2 003

I SBN: 705er -1 face 19 -2 b et w een CPE and car r ier eq uipm ent . Th is int erf ace is t he p oint at w hich The SNI is t1he58int 11 28 t he cuPages: st om er n et w or k ends and t he car r ier n et w or k b eg in s. The f unct ion of t he SNI is t o r ender t he t echn ology and op er at ion of t he car r ier SMD S net w or k t r anspar ent t o t h e cust om er . Figur e 14 - 1 illust r at es t he relat ionships am on g t hese t hr ee com pon en t s of an SMDS net w ork .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Figuialr ean1d4cu-1t t ing. Thedg e SN I Pr ov id es a n I n t e r fa ce Be t w e en t h e CPE an d t he essent e t ech nologies.

Car r i er Eq ui pm en t in SM DS Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SMDS Interface Protocol The SMDS I n t erf ace Prot ocol ( SI P) is used f or com m un icat ion s bet w een CPE and SMD S carr ier equipm ent . SI P pr ov id es con nect ion less serv ice acr oss t h e su bscriber n et w or k int er face ( SNI ) , allow in g t he CPE t o access t he SMDS n et w or k . SI P is b ased on t he I EEE 8 02. 6 Dist r ib ut ed Queue •Du al Bus ( D QDB) Table of st Content andar ds for cell r elay acr oss m et r op olit an - area net w ork s ( MANs) . The DQD B •w as chosen as I ndex t he basis f or SI P because it is an op en st and ard t h at sup por t s all t h e SMDS Iser nt evrn et wfeat or k ing Te chnologie H a ndbook ioned f or comp at ibilit y w it h cur r ent car r ier ice ur es. I n add itsion, DQDB, Four w asthdEdit esign t r ansm st an dar ds, an d it is alig ned wit h em er gin g st an dar ds f or Br oadban d I SDN ( BI SDN) , By Cisco ission Systems, Inc. w hich will allow it t o in t er op er at e w it h br oadb and vid eo and v oice serv ices. Figur e 14 - 2 illust rat es w h er e SI P is u sed in an SMDS n et w or k . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 11 -2 28 . SI P Pr ov id es Conn ect ion le ss Ser v ice Bet w e en t he CPE a nd FiguPages: re 14 Car r i er Eq ui pm en t

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, SIP Levels and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. SI P consist s of t hr ee lev els. SI P Level 3 op er at es at t he Media Access Cont r ol ( MAC) su blay er of Reader ainofa tghreat er un der st an ding of LAN and WAN n et or at k ing, ar t icusublay lar ly ter h eof t he t he dat sa w linillk obt layer e OSI r eference m odel. SI P Level 2 oper atwes t h epMAC har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on dat a link lay er . SI P Level 1 oper at es at t he ph ysical layer of t h e OSI r efer en ce mod el. Figur e 14 a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions 3 illust r at es how SI P m aps t o t he OSI r ef er ence m odel, including t h e I EEE dat a link sublay ers. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals e. Tools andidgu id elines or opt im izing syst per w ill si incr Figu r e 1 4oper -3 .atSI P Pr ov es Ser vfice s Associa t eem dw i tfor h mt hance e Phy caease l and pr odu ct iv it y an d im pr ov e Da eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient t a Lin k La ye r s of t h e O SI M ode l decisions for t h eir net w ork s.

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

SI P Lev el 3 begins op er at ion w hen user in for m at ion is passed t o it in t he f orm of SMDS ser vice dat a un it s ( SDUs) . SMDS SD Us t hen ar e encapsulat ed in a SI P Lev el 3 header and t r ailer . Th e r esult in g f r ame is called a Lev el 3 pr ot ocol dat a unit ( PDU) . SI P Lev el 3 PDUs t hen are passed t o SI P Lev el 2. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. SI P Lev el 2, wh ich oper at es at t he Media Access Cont r ol ( MAC) sub layer of t h e dat a lin k layer , begins operat in g wh en it receiv es SI P Lev el 3 PDUs. Th e PDUs t hen ar e seg ment ed int o un if orCon m lycise sized octsetof) tLevel 2 PDUs, called The passed als t o SI Level 1 f or ov (er53v iew echn olog ies essen t ialcells. t o n et worcells k ingare pr ofession atPall lev els, f rom placement p hy.sical m edium . nov iceont ot he ex pert SI P Lev el 1chapt operat at t h e cov phyerag sicale lay andt ant pr ovt opics ides t he link p rot ocol t hat operat es New er ses include of er im por likephy VoIsicalP and EAP at DS- 1 or DS- 3 r at es bet w een CPE dev ices and t h e net w or k. SI P Level 1 consist s of t he t r ansm ission st em sical Layologies er Conv en cy blay er s. The Cov erag sy e of cut tand ing Phy edge t echn likeregopt icalPrnotetocol wor k( PLCP) ing andsust or age t r ansm ission sy st em sublay er defines t h e ch ar act er ist ics an d m et hod of at t achm ent t o a DS- 1 or h ored by Cisco st PLCP ems, w or ldw idehow leader net w2 or kingarf or n et ed . r elat iv e t o DS- 3 Aut t r ansm ission lin k. Sy The specifies SI P in Level cells e t tohe beI nart er r ang t he DS- 1 or DS- 3 fr am e. PLCP also def in es ot her m anagem ent in for m at ion. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Distributed Queue Dual Bus The Dist r ibut ed Queue Du al Bus ( DQDB) is a dat a link lay er com m unicat ion pr ot ocol designed for use in m et r op olit an - area net w ork s ( MANs) . DQDB sp ecifies a net w ork t opology com posed of t w o un id irect ional log ical b uses t hat int erconn ect m ult iple syst em s. I t is def in ed in t he I EEE 802 .6 •DQD B st and ard Table . of Content s •

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IAn nt eaccess rn et w or kDQD ing Te s Hjaust ndbook Four th Bchnologie descr ibes t h e, oper atEdit ion ion of t he DQD B pr ot ocol ( in SMD S, SI P) acr oss a usernet w or k int er face ( in SMDS, acr oss t he SNI ) . Su ch oper at ion is dist ingu ished fr om t he oper at ion By Cisco Systems, Inc. of a D QDB pr ot ocol in an y ot her env ir onm en t ( f or exam p le, b et ween car r ier eq uipm ent w it h in t he SMDS PD N) . Pub lish er: Cisco Press

Dat e: Sep tem ber 1, 2 003 ThePub access DQDB is 1com p osed of t he b asic SMDS n et w or k com ponent s: I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Car ri er e qui pm en t — A sw it ch in t he SMDS n et w or k oper at es as one st at ion on t he bus. CPE— One or mor e CPE d ev ices op er at e as st at ions on t he b us. SN I — The SNI act s as t he int er face bet w een t h e CPE and t h e car r ier eq uipm ent . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent Figur e ial 14 an - 4 dd ep cu ict t t ings a edg basic e taccess ech nologies. D QDB, w it h t w o CPE d ev ices and one sw it ch ( car r ier equipm ent ) at t ached t o t h e du al bu s. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Figu r e 1 4 -4 . A Ba si c Access DQ DB M a y Con si st of a n En d Node , a New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Rou t e r , a nd a Sw it ch Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions t h eirDQDB net w ork s. An SMDS for access t y pically is ar r ang ed in a single- CPE conf ig ur at ion or a m ult i- CPE conf ig ur at ion. A sing le- CPE access D QDB con figu rat ion consist s of one sw it ch in t he car r ier SMDS n et w or k an d one CPE st at ion at t he sub scr iber sit e. Sin gle- CPE DQDB config ur at ions cr eat e a t w o- nod e DQD B subn et w or k . Com m un icat ion occu rs only bet w een t h e sw it ch and t he one CPE dev ice acr oss t he

SNI . No cont ent ion is on t h e bus becau se n o ot h er CPE devices at t em pt t o access it . A m u lt i- CPE con figu rat ion consist s of one sw it ch in t he car r ier SMDS n et w or k an d a num b er of int er con nect ed CPE dev ices at t he su bscr iber sit e ( all b elong ing t o t h e same su bscr iber ) . I n m ult i- CPE conf ig ur at ions, local com mu nicat ion b et w een CPE devices is possib le. Som e local com mu nicat ion w ill be visible t o t he sw it ch serv ing t h e SNI , and som e w ill n ot . Con t en t ion f or t h e bus by m ult iple d ev ices r equ ir es t he use of t he D QDB dist ribu t ed q ueuing • Table of Content s algor it hm , w hich m akes im plement in g a m ult i- CPE conf ig ur at ion mor e com plicat ed t h an •im plem ent in g I ndex a sin gle- CPE con figu rat ion . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SMDS Access Classes SMDS access classes enab le SMDS net w ork s t o accom m odat e a br oad r ange of t raf fic r eq uir em ent s an d eq uipm ent cap abilit ies. Access classes const r ain CPE d ev ices t o a sust ained or av er age rat e of dat a t ran sf er by est ablishing a m ax imu m sust ained in for m at ion t ran sf er r at e and •a m ax im um allow Table of s of t r aff ic bu rst iness. ( Bur st iness, in t his cont ex t , is t he pr opensit y of edContent d eg ree •a n et wor k t o I exp ndexer ience sudd en incr eases in band wid t h d em an d. ) SMD S access classes Isom nt e rn w or chnologie s ed H a ndbook th itEdit ion agem en t scheme. I n t his case, a cr ed it etetim esk ing ar eTeimp lem ent using , aFour cr ed - man m anagem ent alg orit h m creat es and t r ack s a cr ed it balan ce for each cust om er int er face. As By Cisco Systems, Inc. pack et s are sent int o t he n et w or k , t he cr edit balance is decrem ent ed. New cr ed it s ar e allocat ed per iodically , up t o an est ablished max im um . Cr edit man agem en t is u sed only on DS- 3- rat e Pub lish er: Cisco Press SMDS int er faces, n ot on DS- 1 - r at e int er faces. Pub Dat e: Sep tem ber 1 1, 2 003

I SBN: 158 705 -1 ar 19 -2 Five access classes e sup por t ed f or DS- 3 - rat e access ( corr esp ondin g t o sust ained in for m at ion r at es) Pages: . Dat a11r 28 at es sup por t ed ar e 4 , 10, 16, 25, and 34 Mbp s.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SMDS Addressing Overview SMDSpr ot ocol dat a unit s ( PDUs) car r y bot h a sou rce an d a dest inat ion addr ess. SMDS add resses ar e 1 0- dig it v alu es resemb lin g conv ent ional t eleph one n um bers. • of Content s The SMDS adTable dr essing imp lem ent at ion off ers gr oup addr essing an d secu r it y feat ur es. •

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oup resses allow a single add r essiont o r ef er t o m ult iple CPE st at ion s, w hich specif y t h e ISMDS nt e rn etgr w or k ingadd Te chnologie s H a ndbook , Four th Edit gr oup ad dr ess in t he D est inat ion Add ress f ield of t he PD U. Th e net w or k m akes m ult iple copies of By Cisco Systems, Inc. t he PDU, w hich ar e d eliv er ed t o all m em bers of t he gr oup . Gr oup add r esses redu ce t he am oun t of net w or k r esour ces requ ired for dist rib ut ing r out ing inf orm at ion , r esolv in g ad dr esses, and Pub lish er: Cisco Press dy nam ically discov er ing n et w or k r esou rces. SMDS gr oup addr essing is an alog ous t o m ult icast in g Pub Dat e: Sep tem ber 1 1, 2 003 on LANs. I SBN: 1- 58 705 -1 19 -2

SMDSPages: imp lem ent s t wo secur it y f eat ur es: sou rce ad dr ess v alidat ion and addr ess scr een ing. 11 28 Sour ce add ress v alidat ion ensu res t h at t h e PDU sour ce addr ess is leg it im at ely assig ned t o t h e SNI f rom w hich it orig in at ed. Sour ce add ress v alid at ion p r ev ent s ad dr ess spoof ing, in w hich illeg al t r aff ic assum es t h e sou r ce ad dr ess of a leg it imat e device. Add ress scr eenin g allow s a subscr ib er t o est ablish a pr ivat e vir t ual net w ork t hat ex cludes un w ant ed t raf fic. I f an addr ess is disallowed, t he d at a u nit is n ot d eliv er ed. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SMDS Reference: SIP Level 3 PDU Format Figur e 14 - 5 illust r at es t he for m at of t h e SMDS I n t er f ace Prot ocol ( SI P) Lev el 3 p rot ocol dat a unit ( PDU) . •

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Figu r e 1 4 -5 . A SI P Lev el 3 Pr ot ocol D at a Uni t Consist s of 1 5 Fie lds

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press

[ View full size im age]

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag of cut t echn e opt n etofwor The f ollow in g ed escr iptt ing ionsedge b riefly sumologies m ar izelik t he f unical ct ion t hek ing SI Pand Lev st el or 3 age PD U field s illust rat ed in Figur e 14 - 5. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ernXet+w—orEnsur k in g Tech nologies book , Four t h ns Edw it ion is aD com es t hat t he SIHand P PDU f orm at alig it h ,t he QDBprprehensive ot ocol forrefer m atence . SMDt hat S does enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er w orkect inged not pr ocess or ch ange t he v alues in t h ese f ield s, wh ich m ay be used by sy st emnet s conn t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t o t he SMD S net w or k. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w— it hConsist new ans dofu pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, RS VD zer os. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kinagg— p rof essionals, r egar dless of wexeen pertt he ise.f irst and last seg m en t s of a segm ent ed SI P BEt For m s an associat ion bet Lev el 3 PDU. Bot h field s cont ain ident ical v alu es and are used t o det ect a cond it ion in w hich Reader s wlast ill obt ainent a gof reat er PD un der st ant he ding of LAN w torPDU k ing,arpearbot t icu ly, tw he t he segm one U and f irst segmand ent WAN of t hennetex h lar lost hich har dwr ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on esult s in t h e r eceipt of an inv alid Level 3 PDU. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r et en BAsiz e— Cont ainsr teh heenbsion uff erand allocat iont ion, size.and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy D es,stpr i na t ion ess D A) — Consist s oft he t w realo p art syst em ovid in gaaddr m or e r (ealist ic pict ur e of ws: or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease t yp Occu pies t he signifm ican t bit s of t he f ield. ,The Ty pe pr odu ct iv it y- Ad an ddre imss pr ov e e— eff iciency, help ing4 tm heost r eader ake mor e in t elligent costAdd - effress icient be net eit her 11s.00 or 11 10. Th e for m er indicat es a 6 0- bit indiv idual addr ess, w h ile decisions forcan t h eir w ork t he lat t er in dicat es a 60 - bit gr oup addr ess. - Ad dre ss— Gives t h e indiv idual or gr oup SMDS add ress for t he d est inat ion . SMDS add ress for m at s ar e consist en t w it h t he Nor t h Am erican Num ber in g Plan ( NANP) .

The 4 m ost sign if ican t b it s of t he D est inat ion Add ress subf ield cont ain t he v alue 0 001 ( t h e int er nat ionally def in ed coun t r y cod e for Nort h Am erica) . Th e next 40 b it s con t ain t he binar y - encoded value of t he 10 - digit SMDS addr ess. Th e final 16 ( least sig nificant ) bit s ar e pop ulat ed w it h ones f or pad ding. Sou rce ad dre ss ( SA) — Consist s of t w o p art s: • •

- Ad dre ss t yp e— Occu pies t he 4 m ost signif ican t bit s of t he f ield. The Sour ce Table of Content s Add ress Ty pe f ield can ind icat e only an indiv idual addr ess. I ndex

I nt e rn et w or k ing chnologie s H a ndbook , Four Edit ion - AdTe dre ss— Occu pies t he indthividu al SMDS By Cisco Systems, t he sam Inc. e

add ress of t he sour ce. This f ield follow s f or mat as t h e Addr ess su bf ield of t he Dest inat ion Add ress field.

Pub lish er: Cisco Press

H ig he r l a ye r prot ocol id en t if ie r ( H LP I ) — I n dicat es t he t y pe of p rot ocol en cap su lat ed in t he I n for m at ion f ield . The v alue is n ot im por t an t t o SMDS, b ut it can be used by cer t ain I SBN: 1- 58 705 -1 19 -2 syst em s connect ed t o t he n et wor k .

Pub Dat e: Sep tem ber 1 1, 2 003

Pages: 11 28

H e ade r e xt e nsion l en gt h ( H EL) — I n dicat es t he nu m ber of 32- bit w or ds in t h e Head er Ex t ension ( HE) f ield . Cur r ent ly , t he f ield size for SMDS is f ixed at 12 by t es. ( Thus, t h e HEL v alue is alw ays 001 1. ) e ade e xtion e nsion Cont ains t heone SMD Sw v er sion ber . This conv The uH pdat edr edit of t he( HbE) est— - selling all- innet ork ing num r ef erence p rovf ield idesalso cover ageeys of t he carr ier select ion v alue, w hich is u sed t o select t he p art icular in t er ex ch ange car r ier t o car ry essent ial an d cu t t ing- edg e t ech nologies. SMDS t r aff ic fr om on e local car r ier net w ork t o anot her. ICon nf orm t ion an ds P ngolog ( I nf o essen + P adt ial ) —t oCont su lat ed serels, v icef rom d at a cise aov er v iew ofa tddi echn ies n et ains wor k an ingencap pr ofession alsSMDS at all lev un it ( SDU) and padd in g t hat en su res t h at t h e field en ds on a 3 2bit boun dar y . nov ice t o ex pert . Cycli c re du ncy che ( CR C) im — por Cont ainst opics a v alue er EAP r or check ing. New chapt ernda s include covck erag e of t ant likeused VoI Pfor and Le t h— I n dicat es tedge he lengt h of t h e PDU. Covng erag e of cut t ing t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SMDS Reference: SIP Level 2 Cell Format Figur e 14 - 6 illust r at es t he for m at of t h e SMDS I n t er f ace Prot ocol ( SI P) Lev el 2 cell for m at .

• •

Table of Content s

Figu rI ndex e 1 4 -6 . Sev en Fie ld s Com pr i se t he SM DS SI P Lev el 2 Cel l

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

[ View full size im age] Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The f ollow in g d escr ipt ions b riefly sum m ar ize t he f un ct ion s of t he SI P Level 2 PDU f ield s illust rat ed in Fig ur e 14- 6: Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Access cont rol — Cont ains diff er ent v alu es, d ep en ding on t he d irect ion of in for m at ion f low . New eras s include covaerag of tim t ant t opicsonly like VoI I f t hechapt cell w sen t f r om sw itech o apor CPE device, t he Pinand dicatEAP ion of w h et h er t he Lev el 3 pr ot ocol d at a un it ( PD U) con t ains inf or mat ion is im por t ant . I f t he cell w as sent f rom a CPE Cov erag cut t ingan edge ologies n et ltwor k ingt and st or age dev ice t oe aofsw it ch, d if tthechn e CPE configlikureatopt ionical is mu i- CPE, his field can car ry r equ est bit s t hat in dicat e bids for cells on t h e bu s going f rom t he sw it ch t o t he CPE device. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . N e t w ork cont rol in form a t ion — Cont ains a v alue ind icat ing w het h er t he PDU cont ain s I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat inf orm at ion. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. er — t heI ntdicat er m s, t s, tthe echn ologies, anstd , devices oday 'cell s net orkaing Se gm e ntMast t ype escon whcep et her cell is t he fir t he last used , or ainm tiddle fr w om indu stseg ry . mLear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . en t ed Lev el 3 PDU. Fou r possible seg ment t y pe v alues exist : Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, -t0h 0is— book a at com an d u pContisinu ionplet of emessag e t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. - 0 1 — End of m essage Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr serof v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on - 1ot 0 ocols, — Beg and in ning m essage a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . -11 — Sin gle-r eh segm ent m essage Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals at e. Tools and gu id elines izing3 syst emThe permessage for m anceI w Me ssa geoper I D— Associat es Level 2 cellsf or w itopt h aim Level PDU. D ill is incr t he ease sam e for pr oduall ct ivt hitey segm an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient ent s of a giv en Lev el 3 PDU. I n a m ult i- CPE conf ig ur at ion, Lev el 3 PDUs decisions for ing t h eirf rom net wdiff ork or iginat ers.ent CPE dev ices m ust h ave a dif fer en t m essag e I D . This allow s t h e SMDS net w or k r eceiv ing int er leav ed cells fr om d if fer ent Lev el 3 PDUs t o associat e each Lev el 2 cell w it h t he cor r ect Level 3 PDU. Se gm e nt a t ion uni t — Cont ains t he d at a p ort ion of t he cell. I f t he Lev el 2 cell is em pt y , t h is field is popu lat ed w it h zer os.

Pay loa d le ngt h — I n dicat es how m any by t es of a Lev el 3 PD U act ually ar e con t ained in t h e Segm en t at ion Un it field. I f t h e Level 2 cell is emp t y, t his f ield is pop ulat ed w it h zeros. P ay loa d cy cli c re dun da ncy ch eck ( CRC) — Cont ains a CRC v alue u sed t o det ect er r or s in t he follow in g field s:

• •

- Seg ment Ty pe

Table of Content s

ndex - IMessage ID

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

- SegInc. ment at ion By Cisco Systems,

Unit

- Payload Leng t h

Pub lish er: Cisco Press

Pub Dat e: -Sep tem ber 1 1, 2 003 Payload CRC I SBN: 1- 58 705 -1 19 -2

The Pay CRC v alue does n ot cov er t he Access Con t r ol or t h e Net wor k Cont r ol Pages: 11load 28 I nf orm at ion fields.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary SMDS is a h igh- speed, p ack et - swit ched, dat agr am - based WAN net w or k in g t echn ology used for com mu nicat ion ov er pu blic dat a net w ork s ( PD Ns) . SMDS can use f ib er - or copper - based m edia. I t sup por t s speeds of 1. 54 4 Mbps over DS- 1 t r ansm ission facilit ies, or 44. 73 6 Mbps ov er DS- 3 •t r ansm ission Table Content s facilitofies. •

I ndex

I nt e rn et w or in k ing sH ndbook , Four th w Edit The f ollow g dTe evchnologie ices com pra ise SMDS net orion ks: By Cisco Systems, Inc.

Cu st om er pr em ises equip ment ( CPE) Pub lish er: Cisco Press Pub Car Datr e: ierSep eqtem uipm ber 1ent 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Sub scr iber net w or k int er face ( SNI ) Pages: 11 28 The SNI is t he int er face b et w een t he CPE and car r ier equ ip m en t ; it t r anspar en t ly en ables dat a t r ansm ission bet w een t he t wo net w or ks. SI P of t o t com un- selling icat e b et w ineenone CPE and t he r ier sit e using t h e cover DQDBage st andar d The uSMDS pdat eduses edit ion he bm est allnet w ork ingcar r ef erence p rov ides of acr oss MANs. essentfor ial cell an dr elay cu t t ingedg e t ech nologies. SI P consist of t h e follow ing t hr ee lev els: Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . - SI P Level 3 , w hich operat es at t he MAC su blayer of t h e dat a lin k layer of t h e OSI r ef erence m odelcov erag e of im por t ant t opics like VoI P and EAP New chapt er s include - SI 2 , edge w hicht echn also ologies operat es t heical MAC blayer t h estdat a link lay er of t he Cov erag eP ofLevel cut t ing likat e opt n etsuwor k ing of and or age OSI r efer en ce mod el Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . - SI P Level 1 , w hich operat es at t he phy sical lay er of t he OSI r ef erence m odel I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat SMDS b ot h a sourt oceunand a and d est inat add ress, andem offpor er bot grer oup dr essing enables net wPDUs or kincarr g p ryofessionals derst an dion im plem en t cont ar yhint netad w ork ing and secu rit y f eat ur es. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

Wher e does t h e SNI int er face exist ?

2:

I ndexdoes SI P st an d f or ? What

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

: At whInc. ich By Cisco3 Systems, 4:

lay er s of t h e OSI r efer en ce mod el do each of t he t h ree SI P lev els op er at e?

How d o m ult iple d ev ices r econcile u sage of a D QDB?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

A cr edit - m anagem ent schem e is somet im es used t o im plem ent SMDS access SMD S int er faces only ?

I SBN:classes 1- 58 705 -1 19 -2 on w hich Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 15. Dialup Technology Obj e ct i ve s • •

Table of Content s

Descr ibe t he hist or y of dialup t echnology . I ndex

I nt e rn Descr et w or kibe ing Te chnologie H a ndbook Four th Edit .ion d ialu p consnect iv it y t,echnology By Cisco Systems, Inc.

Descr ibe t he dif fer en t t y pes of dialup m et hod s. Pub lish er: Cisco Press

Discuss t he b en ef it s ( and d raw back s) of dif fer en t d ialu p t echn olog ies.

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction Dialup is sim ply t h e applicat ion of t he Pub lic Sw it ch ed Telep hone Net w or k ( PSTN) t o carr y d at a on behalf of t he end u ser . I t in volv es a cust om er pr em ises eq uipm ent ( CPE) dev ice sending t h e t elep hone sw it ch a ph one nu m ber t o d irect a connect ion t o. The AS36 00, AS520 0, AS53 00, and •AS58 00 are all Table of Content ex am ples ofs r out er s t hat hav e t he cap abilit y t o r un a PRI along w it h bank s of •digit al m odems. I ndexTh e AS251 1, on t h e ot her han d, is an ex amp le of a r out er t h at com m unicat es Iwntitehrnex et w ornal k ingm Teodem chnologie t er s. s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Since t he t ime of I n t ern et w or k in g Tech nologies Hand book , 2 nd ed it ion, t h e car r ier m ark et h as cont inu ed t o gr ow , and t h er e hav e b een dem ands f or hig her m odem densit ies. Th e answ er t o Pub lish er: Cisco Press t his n eed w as a higher d eg ree of int er oper at ion w it h t he t elco equ ipm en t an d t he r ef inem en t of Dat e: Sep tem ber 1 1, 2 003 t he Pub digit al m odem : a m odem capable of d irect d ig it al access t o t he PSTN. Th is has allow ed t he I 1- 58 -1 19 dev elopSBN: ment of705 fast er-2CPE m odem s t hat t ak e adv ant ag e of t he clar it y of sig nal t hat t he dig it al Pages: 28. Th e fact t hat t he dig it al m odem s con nect in g in t o t h e PSTN t h rou gh a PRI or a m odem s en 11 joy BRI can t r ansm it dat a at mor e t han 53 K u sing t h e V. 90 com m un icat ion st andar d at t est s t o t he success of t he id ea.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

A Short Dialup Technology Background Dialup t echnology t races it s or igins b ack t o t h e day s of t he t elegr aph . Sim ple sig nals being sen t across an ex t en ded cir cuit w er e cr eat ed man ually by t ap ping cont act s t og et h er t o t u rn t h e cir cuit eit her on or off . I n an ef for t t o im pr ov e t he serv ice, Alex ander Grah am Bell inv en t ed t h e •t elep hone in Table Content s ed com mu nicat ion f or ev er. Having t h e capabilit y t o send a voice 18 75ofand chang •across t he line I ndex m ade t he t echnology mor e accessible and at t r act ive t o consum er s. By 191 5, t h e IBell nt e rn et w em or k ing s Ha ndbook EditFr ion syst st rTe et chnologie ched fr om New Yor, Four k t o thSan ancisco. Deman d for t h e ser v ice d r ove t echnological inn ovat ion s, w hich led t o t h e fir st t r ansat lant ic p hone ser vice in 192 7 via rad io By Cisco Systems, Inc. signal. Ot her innov at ions alon g t he w ay includ ed m icr ow av e st at ions t h at st ar t ed conn ect ing Am er ican cit ies in 194 8, int egr at ed digit al net w ork s t o imp r ove t h e qu alit y of ser vice, and Pub lish er: Cisco Press com mu nicat ion sat ellit es, w hich w en t int o ser v ice in 19 62 w it h t he laun ch of Telst ar 1. By 1 970 , Pub Dat e: Sep tem ber 1 1, 2 003 m or e t han 90 per cen t of Am erican hom es had t eleph one serv ice. I SBN: 1- 58 705 -1 19 -2

I n 197Pages: 9 t h e11m28odulat or - dem odu lat or ( m odem) w as int r odu ced , and dialup net w or kin g w as bor n. The ear ly m odem s w er e slow er and su bj ect t o pr op riet ar y comm un icat ion schemes. Ear ly uses of m odem s w er e f or int er m it t en t p oin t - t o- poin t WAN con nect ion s. Oft en , t he call w ould com e int o a r eg ular ph one at a d at a cent er . An operat or w ould hear m odem t ones an d p lace t h e han dset ont o a special crad le t hat w as t he mod em . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Iessent n t he ial lat ean1d980 t heedg I TUbegan set t ing up V- ser ies r ecom m en dat ions t o st andar d ize cu ts,t inge Tt ech nologies. com mu nicat ion s bet w een bot h d at a com m unicat ions equ ip m en t ( D CE) and dat a t erm inal equipm ent ( DTE) . Ear ly st andar d s inclu ded t hese: Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . V . 8 — St andar dized t he m et hod t h at m odem s use t o init ially det er m ine t h e V- ser ies m odulat ionerat w hich t hcov ey erag w ill ecom e. Not e t hlike at t VoI h is P st and andar d applies only t o t he New chapt s include of m imunicat por t ant t opics EAP com mu nicat ion session bet w een t he t w o DCE d ev ices. Th is was lat er upd at ed w it h V. 8bis, w hich also ecified som e tof t h eologies comm lik u nicat ardksing betand w eenst or t h age e DTE devices going Cov erag e ofspcut t ing edge echn e option icalstnand et wor ov er t he DCE' s con nect ion . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . V . 2 1 , V. 2 3 , V . 2 7 t e r , V . 2 9 — Defined 300 , 60 0/ 12 00, 2 400 / 480 0, an d 9600 b aud I n t erncom et w mu or knicat in g Tech ion s,nologies r espectHand ively .book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing V . 2 5 , V. Mast 2 5 bier s, tV. t emr— ed t as ser ies of st andar ds f or aut omat dialing, t echnologies. he2 5 t er s, Ser con vcep s, taechn ologies, an d devices used in ed t oday ' s net w ork ing answ erin g, and cont r ol. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Mod s incrt heased gr eat in soph icat e er 19ence 80s. t Th duet hat in par t o t het ial t o all and em speed, is book is alycom plet eistan d uion p- tin o- dt hateelat r ef o tis hewas t op ics aret essen br eaku p of t he Bell syst em in 198 4. Wit h t h e client pr emises eq uipm ent in t h e han ds of f ree net w or kin g p rof essionals, r egar dless of ex pert ise. ent er pr ise, com pet it ion spu r red on t he dev elop ment of speed ier con nect ion s. Mor e recent st andarsd w s ill inclu Reader obtde aint haese: g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions V .re 3 2 con b is,cept V . 3 comp 4 , V. 9r eh 0— andar 00,and 336ad 00, t o 5r600 b aud u nicat t o en su enSt sion anddized r et en144 t ion, dit and ionalup r esou ces 0f or fu rt comm her st udy . ion speed s. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich V . 1 1 0 — Allow ed an asy nchr onou s DTE device t o use an I SDN DCE ( t er m inal ad apt er ) . pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu it y an dser imvpr e er effeiciency, e in t9elligent cost - eff The f irctstivaccess erov sw t he AS2help 509ing andt he t h er eader AS251m1.ake Th emor AS250 cou ld ,sup por t 8icient incom ing decisions for t h eir net w ork s. connect ions u sing ex t er nal m odems, w h ile t he AS25 11 cou ld sup por t 1 6. Th e AS520 0 was int r odu ced w it h 2 PRI s and cou ld sup por t 4 8 user s u sing d ig it al m odem s—t his r ep resen t ed a m ajor leap for w ar d in t echnology . Modem densit ies hav e increased st eadily , w it h t he AS53 00 supp ort in g four and t hen eigh t PRI s. Th e AS580 0 was lat er in t r oduced t o fill t he needs of car rier class in st allat ions need in g t o h andle doz en s of incomin g T1 s and hu ndr eds of user connect ions

A coup le of out d at ed t echnologies bear m ent ionin g in a hist orical d iscussion of dialer t echnology . 56 Kf lex is an older ( p re- V. 90) 56 K mod em st andar d t hat w as pr oposed b y Rock well. Cisco supp ort s ver sion 1 .1 of t h e 56 Kflex st andar d on it s int er nal m odem s, bu t it recom mend s m igr at ing t he CPE m od em s t o V. 90 as soon as possib le. An ot her out d at ed t echn olog y is t he AS51 00. Th e AS51 00 w as a j oint v ent u re b et ween Cisco and a m odem m anu fact ur er . The AS51 00 w as cr eat ed as a w ay t o increase m odem densit y t h rou gh t he use of quad m odem car ds. I t in volv ed a gr oup of AS251 1s b uilt as car ds t h at w er e inser t ed int o a back plane shar ed by qu ad m odem car ds, and a d ual T1 car d. • Table of Content s •

I ndex

Today d ialu p is st ill u sed as an econ om ical alt er nat iv e ( depend in g on t he connect ion I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion r eq uir em ent s) t o dedicat ed con nect iv it y . I t h as imp or t ant uses as backu p con nect iv it y , in case By Systems, Inc. t heCisco pr imar y lines go dow n. Dialup also off er s t he flex ibilit y t o cr eat e dy nam ic connect ions as needed. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Dialup Connectivity Technology This sect ion p rov ides inf orm at ion fr om var ious d ialu p op t ions. Also included ar e adv anced opt ion s for dialup con nect iv it y and v ar ious dialup m et hods. •

Table of Content s

•

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Plain Old Telephone Service I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

The r egu lar phon e lin es used in voice calls ar e ref er r ed t o as Plain old t elephon e ser v ice ( POTS) . They ar e ub iquit ous, f am iliar , an d easy t o obt ain; local calls ar e nor m ally fr ee of char ge. This is lish er: Cisco ice Press t he Pub kind of serv t hat t he p hone net w ork w as built on . Soun ds car ried over t h is ser v ice ar e Pub Dat e: Sep tem 2 003t im es per second ( u sing 8 bit s p er sam p le) in t h eir con ver sion t o sam pled at a r at eber of 181,000 I SBN: 158 705 -1 19 -2 digit al sig nals so t h at soun d can be car r ied on a 6 4 k bp s chann el at accep t able levels. Pages: 11 28

NO TE The uSo pdat edit of t he b est - selling one net w ork ingvroice ef erence ides cover w hed at 's anion accep t able level? St u alldiesin-hav e show n t he ran gep trov o be 3 00 Hz age t o of essent ial an d cu t t ingedg e t ech nologies. 34 00 Hz. 40 00 Hz cov er s t h e r ange, b ut accor ding t o Ny qu ist ' s t h eor em , sound m ust be sam pled at t w ice t hat r at e t o cap t ur e bot h t h e high and t h e low of t he sou nd w aves. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . The encod in g an d decod in g of voice is don e by a piece of t elco g ear called a COD EC. The CODEC New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP w as needed t o allow b ack w ar d- comp at ibilit y w it h t he old analog phon es t hat wer e alr ead y in w idesp r ead use w hen t he edge d igit al n et wologies or k w as rodical uced most foun d in t h e hom e Cov erag e of cut t ing t echn likint e opt n .etThu wors, k ing andphon st ores age ar e sim p le analog devices. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Dialup connect ivit y acr oss POTS lin es has hist or ically b een lim it ed t o ab out 3 3, 60 0 b ps v ia m er r ed t o as V. 34 speed Recent pr ovem s pr h ave in cr eased he spteed I n odem t ern et—oft w or ken in gr ef Tech nologies Hand book ,s.Four t h Edim it ion , is a ent com ehensive refertence hat at w hich dat a can be sent fr om a digit al sou rce t o a m odem on a POTS line, b ut usin g POTS lines enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing on bot h end s of t he conn ect ion st ill result s in V. 34 connect ivit y in bot h d ir ect ions. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is Interface book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Basic Rate net w or kin g p rof essionals, r egar dless of ex pert ise. IReader nt end ed hom e use, t hiserap of I SDN uses t heWAN sam n e et copper as ap ar POTS line, s wfor ill obt ain a g reat unplicat der stion an ding of LAN and w or k ing, t icu lar ly tbhut e it off ers dir ect digit al conn ect iv it y t o t he t elep hone n et wor k . A sp ecial p iece of equipm ent kn ow nonas har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided a t er m inal ad apt er is r eq uir ed ( alt h ough , dependin g on t h e count r y , it m ay b e int egr at ed in a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew questt oions tt he er con or DCE ev ice) . Alw ay s and m akreetsu t o check—t heional plu gr uesou sed rtces o con o t he w all. o enrou su tre cept dcomp r eh en sion enr teion, and ad dit f ornect fu rt ther st udy sock et look s t h e sam e w h et h er it 's t h e S/ T or U dem arcat ion point . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Nor mally , a Basic r at e in t er f ace ( BRI ) int er face has t w o B ( bearer ) chan nels t o car r y dat a, and pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease one D ( d elt a) channel t o car ry con t rol and sig naling infor m at ion. Local t elep hone car r ier s m ay pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient hav e dif fer en t p lan s t o su it local needs. Each B chan nel is a 6 4 K line. The in divid ual 6 4 K decisions for t h eir net w ork s. chann els of t h e t elep hone n et wor k ar e com m only r ef er r ed t o as d ig it al ser v ice 0 ( D S0) . Th is is a com mon denom inat or r eg ard less of t he t yp es of ser vices off er ed, as w ill be show n lat er in t h is chapt er . The BRI int er face is a dedicat ed connect ion t o t h e sw it ch and w ill r em ain up even if n o calls ar e placed.

NO TE So h ow do t hr ee chann els g et across a sin gle pair of copp er w ir es? I t 's a pr ocess called t im e div ision m ult iplexin g ( TD M) . Th e sig nals on t he cable ar e d iv ided int o t ime slot s. • Tablet h ofatContent This m eans b ot h sen ds of t h e lin e m ust sy nchr onize t h eir t im ing w hen t he line is • init ialized I ndex . Hav in g t he line u p show s a st at e of MULTI PLE_FRAME_ ESTABLI SHED , I nt e rnw ethich, w or k ing amTe ong chnologie ot h er s tHhing a ndbook s, means , Four tht he Editclock ion ing is sy nchr onized an d t he t w o devices com mu nicat in g are now sending TDM f ram es back an d f or t h. By Cisco Systems, Inc. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

T1/E1I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The T1 / E1 line is d esigned for use in b usinesses. T1 boast s 24 TDM chann els r un acr oss a cable w it h 2 copp er pair s. E1 off er s 3 2 ch annels, alt houg h 1 is d ed icat ed t o f r ame sy nchr onizat ion . As is t he case w it h t he BRI , t he T1 / E1 connect ion g oes dir ect ly int o t he t elco sw it ch. The con nect ion is dedicat ed, so lik e a BRI , t he T1 / E1 r em ains con nect ed and com mu nicat in g t o t h e swit ch all t he t im e—ev en if t h er e ar e no act ive calls. Each of t he chan nels in t h e T1/ E1 is j ust a B ch annel, The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of w hich is t o say t h at it ' s a 6 4- K D S0. Th e T1/ E1 is also r efer red t o as digit al ser vice 1 ( DS1) . essent ial an d cu t t ing- edg e t ech nologies. The Nor t h Am erican T1 u ses f r ames t o defin e t he t im ing bet w een ind iv idu al chann els. For T1s, each Con f ramcise e h as 24v iew 9- b sit of chan nels ( 8 ies b it sessen of dat a, t1o bnitetfwor or frkam . That adds 1 93 s p er ov er t echn olog t ial inging) pr ofession als atup allt olev els,bit f rom fr am e. So, at 800 0 of t hose per secon d, t h e T1 is car r y in g 1 . 544 Mb ps bet w een t h e swit ch and nov ice t o ex pert . t he cu st om er p rem ises equ ip ment ( CPE) . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP The E1 sim ilarly u ses f r ames f or t im ing, b ut t he E1 u ses 3 2 8 - bit ch annels f or a 2 56- b it f ram e. AgainCov at terag he 80 00 cut Hzt ing r at e,edge t h e tch annel y ield lik s 2. Mbps t raf fic band et ween t he sw it ch an d t he e of echn ologies e 04 opt8 ical n etof wor k ing st or age CPE. Most of t h e w or ld u ses t h e E1. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Depend in g on t h e r eg ion, v ar iou s line code an d f r amin g schem es will h ave t o be used f or t he CPE and h ek swit ch t onologies u nder st Hand and each her . tFor le,aincom Norprt hehensive Amer ica,refer t he ence encoding I n t ern et wt or in g Tech bookot , Four h Edexam it ion ,p is t hat sch em e m ost oft en seen is called b inar y 8 zer o su bst it ut ion ( B8ZS) , an d t he m ost on ing enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int ercom net m w ork fr am ing don e is ext end ed super f r ame ( ESF) . The t elco t h r ough w hich t he T1/ E1 ser vice t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net wis ork ing pu rchased munst how ind icat w h ich code anwd or f r kin amin shou ld bies e used. indu st ry . Lear to e incor por line at e int er net g tgechn olog in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, For h er ar eplet t w oe tan ypdesu pof t oT1/d E1 ary Rat I ntter PRI are ) and chann and dialup speed,pu t hrp is oses, book tis a ecom at e: rPr efim er ence t o et he opface ics t(hat essen t ialelt o all associat ed sign alin g ( CAS) . PRI and CAS T1/ E1 s ar e nor m ally seen in cen t r al locat ion s t hat net w or kin g p rof essionals, r egar dless of ex pert ise. r eceive calls f rom rem ot e sit es or cust om er s. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Primary Rate Interface t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy T1 Pr im ar y r at e int er face ( PRI ) ser v ice of fer s 23 B ch annels at 64 kb ps at t he cost of on e Dsyst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich chann el ( t he 2 4t h chann el) for call signaling . Usin g NFAS t o allow m ult iple PRI s t o use a sin gle D pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease chann el can m inim ize t his d isad van t age. E1 PRI ser vice allow s 30 chann els, b ut it uses t he 1 6t h pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient chann el for I SDN sig naling. The PRI ser vice is an I SDN conn ect ion. I t allow s eit h er voice- gr ade decisions for t h eir net w ork s. ( m odem ) or t ru e I SDN calls t o b e m ade and r eceiv ed t h rou gh t he T1 / E1. This is t h e t yp e of ser v ice most oft en seen in access serv er s because it f ost er s hig her connect ion speeds.

Channel Associated Signaling

T1 Chan nel associat ed sig naling ( CAS) lines h ave 24 56K ch annels—par t of each ch annel is bor r ow ed f or call sig naling. This t y pe of serv ice is also called rob bed- b it signaling. The E1 CAS st ill uses only t h e 16t h chan nel for call sign alin g, b ut it uses t he R2 in t ern at ional st and ard f or analog call sig nals. CAS is not an I SDN int er face; it allow s only an alog calls t o com e int o t h e access ser v er . Th is is oft en don e t o allow an access ser ver t o w ork wit h a ch annel b ank , and t his scenar io is seen m or e •com mon ly in Table s Eur ope, an d Asia. Sou tof h Content Am er ica, •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

NO TE Pub lish er: Cisco Press Pub Sepktem 1, 2nals 003 SoDat w e: h at indberof1 sig

need a call sig naling chann el? Each end of a call mu st ind icat e t oI SBN: t he ot h er d -2 w h at is g oin g on w it h a m essag e such as caller I D in for m at ion, on1- 58 705en -1 19 hook Pages:or11off 28 - hook st at u s, and call set up . I f a m essage is sent fr om t he sw it ch ind icat ing t hat a new call is coming in, t he CPE m u st t ell t he sw it ch w h ich chann els ar e av ailable. I f t he sw it ch sends a call int o a chan nel t hat isn't exp ect ing it , t h e sw it ch w ill get back a m essag e indicat ing t hat t he ch annel isn' t av ailable. An access ser ver m ust m ain t ain st at e inf or mat ion on it s lines and be pr ep ared t o coor dinat e inw ard an d ou t w ard calls w it h t he sw it ch. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing Modems

pr ofession als at all lev els, f rom

nov ice t o ex pert .

From New a t erchapt m in ology st and point , a meodem is considered comPmand un icat ion equip ment ( DCE) , er s include cov erag of im por t ant t opics dat likea VoI EAP and t h e device using t h e m odem is called dat a t er m inal equ ipm en t ( D TE) . As in dicat ed ear lier , m odem s erag m uste ad t o aedge numtber com m unicat ion st n anetdar t o wand ork stwor it hage ot h er mod em s: Cov of here cut t ing echnofologies lik e opt ical words k ing Bell1 03, Bell21 2A, V. 21, V. 22, V. 2 2bis, V. 23, V.3 2, V. 32 bis, V. FC, and V. 34, t o n ame a f ew . TheseAut st andar lect aSydu al analog conv er leader sion m odel, is show n in h oredds byref Cisco st ems, w or ldw ide in netw which or king f or t he I n Figur t er n ete. 15 - 1. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. t er m s,mu conncep echn ologies, d devices used in ua t oday ' s net w ork ing Figu rMast e 1 5er-1t he . Com icat s,t i ton St a nd aran ds Ref l ect a D l An al og indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog Con ve r sion M ode l ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Adv ances in access ser ver t echnolog y hav e allow ed t he developm ent of n ew st andar ds t o t ak e adv ant ag e of bet t er connect ivit y at t h e ser v er en d. These st andar d s ar e X2, 5 6 Kf lex , an d V. 90 . X2 and 56 Kflex r epr esent ear lier pr opr iet ar y st an dar ds t h at w er e mad e obsolet e by V. 90 . The assu m pt ion mad e by all t hese st an dar ds is t h at t he access ser v er has d ig it al connect ivit y t o t h e t elep hone n et wor k . The new m odel is show n in Figur e 15 - 2. •

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Figu r e 1 5 -2 . N ew St a nda r ds M ode l

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Not ice t hat t he sign al goes t h rou gh only one analog con ver sion . Becau se t he conv er sion is done on t heCov clien t 'sesid ficedge g en ert echn at ed ologies by t h e lik client mical odem limit ed and t o V.st3or 4 age speeds. The t raf fic erag of e, cutt raf t ing e opt n etis wor k ing com in g f r om t he access ser ver is n ot sub ject t o t he n oise p r oblem s t h at an an alog conv ersion w ouldAut inthr ored odu ce, it can sen t watorm uch by so Cisco Sy bsteems, ldw ideh igher leaderspeeds. in net wThus, or kingt he f orclient t he I ncan t er nreceiv et . e dat a at v .9 0 sp eeds but can send dat a at on ly V.3 4 sp eeds. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat So h ow does it kin r eally or k? Her e'st ot he erall flow t hplem e daten a tascont it gem oespor t hrarough a net modwem as enables net w or g p rwofessionals un ov derst and an dofim y int er ork ing show n in FigurMast e 15er - 3.t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t echnologies. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w orFigu kin g prrof e essionals, 1 5 -3 . O ve r egar r adless ll Fl ow of exof pertDa ise.t a a s it Goe s Thr ou gh a M odem Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv[ ed . Fu ent al t ech nology inf or mat ion is pr ov ided on View fullndam size im age] a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Going f rom t he D TE d ev ice, t he dat a is sent t hr ough t h e UART, w hich h andles bu ff er ing and f low The ruol cont pdat w ited h t edit he hion ost of . The t hedbat est a -com selling pr essor all- inp asses one net t he w ork dating a t or ef t he erence packet p rov izer, ides w hich cover p ut age s aof essentsum check ial an ond itcuand t t ingsen edg dseitt ech on nologies. t o t he D SP. The p ack et izer also hand les r et r ansm it s if t he d at a doesn' t get t hr oug h t o t he ot her DCE. The dat a t rav els onw ar d t o t h e digit al t o analog pr ocessor , w hich pushes t h e dat a out t he RJ11 jack t o t he p hone line. Receiv ing dat a goes in t he r ev er se Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom pr ocess. nov ice t o ex pert . I n t heory , V. 90 m odem s could send d at a at 56 k bps, b ut b ecau se of lim it s placed on t h e phon e New chapt erent s include cov erag portthat ant is t opics like P and lines by g over nm agencies, 53 kebpofs im is all cur r en t lyVoI possib le. EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

PPPAut h ored

by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

IPPP n t ern et wsor in gion Tech Four h Ed ion is aofcom pr ehensive refer ence b ear mkent in gnologies b ecau seHand it is book so v it, al t o tt he opiter at, ion dialup t ech nologies. Un t ilt hat PPP enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w orkt oing cam e along in 1 989 ( RFC 113 4—cur r en t ly up t o RFC 1 661 ) , dialup pr ot ocols w ere sp ecific t he tpr echnologies. er To t heuse t er m t s,ocols, t echnitologies, an d devices used in t oday net w ork ing ot ocol b eingMast u sed. ms, ultcon iplecep p r ot w as necessary t o encapsulat e an'ys ot her indu st ry . Lear n how t o sincor intpr erot net w ort hkin t echnlink ologwies t o ning. a LAN/ WANofenv ir onm ent . pr ot ocols w it hin packet of wpor h atat eveer ocol eg dialup as in r un Many the Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, . pr opr iet ar y lin k m et h ods ( such as SLI P) didn 't ev en hav e t he capab ilit y t o negot iat e addr essing and speed, t h is book is a com plet e an d u pt od at e r ef er ence t o t he t op ics t hat are essen t ial t o all Fort unat ely , PPP d oes t his and m any m or e t h in gs w it h flex ib ilit y an d ex t ensibilit y. PPP net w or kin g p rof essionals, r egar dless of ex pert ise. connect ion est ablishm ent h appens in t h ree p hases: Link Cont r ol Pr ot ocol ( LCP) , aut hent icat ion, and Net w ork Cont r ol Pr ot ocol ( NCP) . ( See Ch apt er 13 , " Poin t - t o- Point Prot ocol, " f or m or e Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e inf orm at ion. ) har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . LCP Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich LCP is t h e lowest er Tools of PPP. Because PPP fdor oes n im ot izing f ollowsyst a clien t / ser er ance mod el, h ease ends of pr of essionals operlay at e. and gu id elines opt em per forv m w illbot incr tpr heodu point p oint nect ioniciency, m ust agr eeing on tthe h e rnegot ot ocols. W hen n, eg ot iat b eg ins, ct iv-itt oy an d imcon pr ov e eff help eaderiat med akeprmor e in t elligent cost - effion icient each of t h for e peer s wnet anw t ing t o est ablish a PPP conn ect ion m ust send a conf igur e r equest decisions t h eir ork s. ( CONFREQ) . I nclud ed in t he CONFREQ ar e any op t ions t hat ar e not t he lin k default . These oft en include max im um r eceiv e unit , asy nc con t rol char act er m ap, aut h en t icat ion pr ot ocol, and t h e m agic nu m ber. At t h is st age, t he p eer s negot iat e t heir aut h en t icat ion m et hod and indicat e w het her t h ey will sup por t PPP m ult ilink .

I n t he gener al f low of LCP negot iat ion s, t here are t hr ee possible r esponses t o an y CONFREQ:

1 . A conf igur e- ackn ow ledg e ( CONFACK) m ust b e issued if t he p eer r ecog nizes t he op t ions and agr ees t o t h e v alu es seen in t h e CONFREQ. 2 . A conf igur e- r ej ect ( CONFREJ) m ust be sent if an y of t he op t ions in t he CONFREQ ar e not Table( such of Content s r ecogn ized as som e vend or- sp ecific op t ions) or if t h e v alu es for an y of t he op t ions • I ndex hav e been ex plicit ly disallow ed in t h e config ur at ion of t h e peer. •

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 . A conf igur e- negat iv e- ack now ledge ( CONFNAK) m ust be sent if all t he opt ion s in t he CONFREQ ar e r ecognized, b ut t he v alues ar e not accept ab le t o t h e peer .

By Cisco Systems, Inc.

lish peers er: Ciscocon Press ThePub t wo t inue t o exchan ge CONFREQs, CONFREJs, and CONFNAKs u nt il each sends a Pub Dat e: unt Sep tem ber dial 1 1, 2 003 CONFACK, il t he con nect ion is br ok en, or u nt il on e or bot h of t h e peers in dicat es t hat t he negot iat I SBN: ion 1-cannot 58 705 -1be 19 -2com plet ed. Pages: 11 28

Authentication Aut h en t icat ion is an opt ion al ph ase, b ut it is highly r ecomm end ed on all dial con nect ion s. I n The e som u pdat inst ances, ed editition is of a rtequir he b est em- en selling t f or allpr oper in- one oper net atw ion—d ork ing ialer r ef erence p rof iles,p rov being idesa cover case age in point of . essent ial an d cu t t ing- edg e t ech nologies. The t wo pr incipal t yp es of au t hent icat ion in PPP are t he Passw ord Aut h en t icat ion Pr ot ocol ( PAP) and t h e Challenge Han dshak e Aut h en t icat ion Pr ot ocol ( CHAP) , defined by RFC 13 34 and upd at ed Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom by RFC 1 994. nov ice t o ex pert . When discussing au t hent icat ion, it is helpfu l t o use t he t er m s r eq uest er an d aut h en t icat or t o New s include e of im por anther t opics VoIcon P and dist ingu ishchapt t h e rer oles p lay edcov by erag t he devices at teit end like of t he nectEAP ion , alt hou gh eit h er peer can act in eit her r ole. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Requ est er d escr ibes t he d ev ice t hat r eq uest s net w ork access and su pplies aut h en t icat ion h ored byaut Cisco stor ems, or ldw leader net aut w orhent kingicat f orion t heinfor I n t er . and eit her inf ormAut at ion; t he h en tSy icat v erwif ies t heide v alidit y ofint he mnatetion allow s or disallows t he conn ect ion. I t is comm on f or bot h peers t o act in b ot h r oles w hen a DD R Iconnect n t ern etion w oris k inbein g Tech nologies Four t h Ed it ion , is a com pr ehensive refer ence t hat g mad e bet wHand een rbook out er, s. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing tPAP echnologies. Mast erAft t he er m s, con t s,plet t echn an dnegot devices used t oday w eat ork ed ingly is f air ly sim ple. er t su ccessf ulcep com ion ologies, of t h e LCP iat ion , t heinr equ est' sernet r ep indu st ry n how t o incor por at e int erion net w oross kin gt hteechn in tau o at hent LAN/icat WAN onm ent sen ds it s. uLear ser nam e/ passwor d comb inat acr lin kolog un ties il t he or renv espironds wit h. Com pletowledg e w it h ment new an pdat chapt y , tst or age, opt w or k in g,t he scalabilit an ackn orduunt il t hed e lin k is er brsokon ensecur . Theitau hent icat or mical ay dnet isconnect link if ity, and is book is anam come/ plet e anor d du pt o-bin d atat e ion r ef er o t he t op ics t hat are essen t ial t o all det erspeed, min es tthhat t he user p assw com is ence n ot vtalid. net w or kin g p rof essionals, r egar dless of ex pert ise. CHAP is som ew hat mor e com plicat ed . The aut hent icat or sends a challen ge t o t he r equ est er, Reader w illr espond obt ain sa w g reat un der st an vding WAN n et w orak"ing, t icu lar ly" ftunct h e ion t o w hich tshen it h aerv alu e. This alueofis LAN calcuand lat ed by using on e-pwaray h ash har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov hash t he challenge and t he CHAP passw ord t og et h er . Th e r esult in g v alue is sent t o t h e ided on a b rhoad r ang of int egr al t sy s and ices,h ost in clud inge det revfriew ions aut en t icat orealong w it h hestrem eq uest er 'serv s CHAP nam ( w hailed ich mdescr ay beiptdion iff ers,ent om quest it s act ual thost o en nam su re e)con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . in a r esp onse m essage. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst pr ovid in gr eads a m ort heer ealist pict of tr he realor ld n et w or k ingup entvir ent sedin w hich The em au ts, hent icat or host nicam e ur in et he espon sewmessage, looks heonm ex pect pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill increr ease passw ord f or t hat host nam e, and t hen calculat es t h e valu e t hat it ex pect s t he r equest t o send pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient in it s r espon se b y per for m ing t he sam e hash fu nct ion t he r eq uest er perf or med. I f t h e r esult in g decisions for orkicat s. ion is successf ul. Failur e should lead t o a d isconn ect ion. By RFC v alues m at ch t, hteir he net aut w hent st andar d s, t he aut hent icat or can r equ est anot her au t hent icat ion at any t im e d ur ing t he connect ion.

NCP

NCP negot iat ion is con duct ed in m u ch t he sam e m ann er as LCP negot iat ion w it h CONFREQs, CONFREJs, CONFNAKs, and CONFACKs. How ever , in t his p hase of negot iat ion, t he elem ent s being negot iat ed hav e t o do w it h hig her- lay er pr ot ocols—I P, I PX, b r id ging, CDP, and so on. One or m or e of t hese pr ot ocols m ay be n eg ot iat ed . Refer t o t he follow in g RFCs for m ore d et ail on t heir associat ed pr ot ocols: •

of Cont Content RFC 133Table 2 " IP rols Prot ocol"

•

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I nt e rn RFC et w or155 k ing2Te" chnologie , Four th Edit ion I PX Contsr Hola ndbook Prot ocol" By Cisco Systems, Inc.

RFC 137 8 " AppleTalk Cont r ol Pr ot ocol"

PubRFC lish er:163 Cisco 8 "Press Bridg ing

Cont r ol Prot ocol"

Pub Dat e: Sep tem ber 1 1, 2 003

RFC 2 705 " DECn et Con t rol Pr ot ocol" I SBN:176 1- 58 -1 19 -2 Pages: 11 28

RFC 176 3 " VI NES Con t rol Pr ot ocol"

A Couple of Advanced Considerations The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent The Mult ialilin ankd Point cu t t ing- t o-edg Poine t t Pr ech otnologies. ocol ( MLP, RFC 199 0) feat ur e p rov ides a load - balanced m et hod for sp lit t ing and r ecom bining pack et s t o a single end syst em acr oss a logical pip e ( also called a bu ndle) f or med by m ult ip le lin ks. Mu lt ilin k PPP p rov ides ban dw idt h on dem and and r ed uces Con cise lat ov en er vcy iew s of iesect essen wore kting alsmatultall levdor els, f rom t r ansm ission acr osst echn WANolog conn ions.t ial At ttohen et sam im e,pritofession p rov ides iv en nov ice t o ex pert . int er operab ilit y , p ack et f r agm en t at ion w it h p rop er sequ en cin g, and load calculat ion on bot h inbou nd and out b ound t r af fic. The Cisco im plem en t at ion of mu lt ilink PPP supp or t s t he Newatchapt erds pinclude cov erag e ofspecif im por t ant like VoI fr ag ment ion an ack et sequencing icat iontsopics in RFC171 7.P and EAP Cov PPP erag w e or ofks cutov t ing t echn ologies lik e topt ical( sin n etgle worork ing and st:or age Mu lt ilink er tedge h e follow ing int erf ace y pes m ult ip le) Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Asyn ch ron ous serial in t erf aces I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables BRInet s w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu stPRI ry .sLear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, andlt ichassis Mu speed, t hmisult book ilin k is PPP a com ( MMP) plet, eon ant dheu pot her t o- dhan at e d, r efperrov ence idest ot he t headdit t op ics ional t hatcap are abilit essen y for t iallint oksall tnet o tw eror mkin inat g ep at rof m essionals, ult iple r out r egar er s dless w it h of diffex erent pert ise. r em ot e ad dr esses. MMP can also han dle bot h analog and dig it al t r aff ic. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw This f unct ar e,ionalit pr ot ocols, y is inand t en ded ser vfor icessitinv uatolv ioned s .inFuwndam h ich tent herale is t ech a lar nology ge pool inf or ofmat d ialionin isusers, pr ov ided an d on a a b r oad single access r ang eserv of int er egr cannot al sy st prem ov ide s and enoug servhices, d ial-in includ p orting s. MMP det ailed allow descr s com iptpanies ion s, rev t o iew pr ovide questaions t o en sudre single ialu con p ncept um ber comp t o rteh heir en sion usersand an dr et t oenap t ion, ply tand he sam ad dit e ional solut ion r esou t o ran ces alog f or an fu rt d her d igitstaludy calls. . Cov erag This f eateurise also allows extI end n t ern edetn ot seronly v ice tpor ovider new n s, et wor for kex ing amconcep ple, t o t allocat s, but also e a sing t o old le er I SD , legacy N r ot ar y syst nu mb em ers,t oprsever ovid inalg I aSDN m orPRI e r ealist s andicnot picthav ur ee of t o t wor he realr y abou w ortldw nh et w h er or kaing user en'svirsecon onm ent d link s iniswon hich t he pr of essionals sam e rou t er. oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient MMP doesfor nott hr eir eq uir e wr econf decisions net ork s. igur at ion of t eleph one com pany sw it ches.

AAA Anot h er t echn ology t h at shou ld be ment ion ed b ecause of it s im por t ance is Au t hent icat ion,

Aut h orizat ion , and Accou nt ing ( AAA) . Th e pr ot ocols used in AAA can be eit her TACACS or RADI US. These t w o p r ot ocols w er e dev eloped in su ppor t of a cen t r alized m et h od t o k eep t r ack of users and accesses m ade on a net w or k. AAA is emp loyed by set t ing up a ser ver ( or g r oup of ser v ers) t o cent r ally adm inist er t he user dat ab ase. I n for m at ion such as t h e user ' s passw ord , w hat addr ess should be assigned t o t h e user, and w hat pr ot ocols t he user is allow ed t o r un can be con t rolled and mon it or ed fr om a single w or k st at ion . AAA also h as pow erf ul audit ing capabilit ies t hat can b e used t o follow ad m in ist r at iv ely im por t an t t r ends su ch as conn ect ion speed s and disconnect r eason s. Any m edium or larg e dialup inst allat ion shou ld b e using AAA, • Table of Content s and it ' s not a b ad idea for sm all shops, eit her . •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Dialup Methods Most rou t er s sup por t au t om at ed m et hods for d yn am ic lin ks t o be con nect ed w hen t raf fic t hat needs t o get t o t he ot her end ar riv es. Cisco' s imp lem ent at ion is called dial- on- d em and r out in g ( DD R) . I t pr ovides WAN connect ivit y on an econ omical, as- needed b asis, eit her as a pr im ary lin k •or as b ack up Table f or aofnContent ondial sser ial link . •

I ndex

IAt nt eitrn w or k ,ing Te chnologie s H aext ndbook , Four Editing ion . I nt erest ing pack et s are rou t ed t o a d ialer s etheart DDR is j ust an en sion ofthr out int er face t h at t r igger s a dial at t em pt . Each of t h e concep t 's dialer int er face an d int erest in g t r af fic By Cisco Systems, Inc. bear ex planat ion. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

What's I SBN:a1-Dialer? 58 705 -1 19 -2 Pages: 11 28

The t er m dialer h as a f ew m ean ings, d ep en ding on t he specifics of t he conf igur at ion, but in gener al, it r efer s t o t he int er face w her e t he rou t ing is act ually happ en ing. Th is is t he in t er f ace t hat k now s t h e addr ess and phon e nu mb er w here t he t r aff ic is supp osed t o g o. When lookin g at t he rou t ing t able, t he dialer in t er f ace sh ould be t h e int erf ace r ef er enced f or t he next hop t o reach t he net w ork on t h e ot her side. The dialer in t er f ace does not hav e t o b e t he phy sical in t er f ace t hat The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of is doin g t h e dialing, but it can be m ade so by p lacing t h e con figu r at ion com m and di al e r i nessent ial an d cu t t ing- edg e t ech nologies. ba nd in a phy sical in t er f ace. Th er eaft er , t h e int erf ace becomes a dialer . For ex am ple, an asy nc int er face is not a dialer b y defau lt , bu t p lacing t he con figu rat ion com man d di al e r i n- ban d in t h e asyn cCon int er face behav t hatt ial in t er ace. Fork ing ex amp le, callsals r eceiv byels, t hat cise ovcauses er v iew sdialer of t echn ologior ieson essen t of n et wor pr ofession at alledlev f rom asyn cnov int ice er face aft er apply ing t he com m and w ill hav e an id le t imeout app lied t o t he connect ion t o ex pert . fr om t hen on . An ex am ple of a phy sical in t erf ace t hat is also a d ialer b y defau lt w ould be t h e BRI int er face. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

NO TE I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat An idle er gis pused by Ciscot oI OS t o t r ack owd long a con ion gone it net h out enables net wt im or kin r ofessionals un derst and han im plem en tnect cont emhas por ar y intwer w ork ing int er est ing t r af defau , itcep ' s set 2 mologies, inut es; an af tderdevices 2 m in utused es ofininact iv it' sy,net t hew call t echnologies. Mast erfic. t heByt er m s, lt con t s, ttoechn t oday ork ing isryhu ng up. indu st . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Beyon d m ak ing ph ysical int er faces in t o d ialer s, t her e ar e int erf aces called d ialer in t er f aces. These logical intaergfaces callstupon r eal erfand acesWAN t o place Thep ar adv ant Readerar s ew ill obt ain reat ert hat un der an ding of int LAN n et wcalls. or k ing, t icu larage ly t of h eusing a dialer inte, er pr face is f lex and ibilit ser y. Av ices gr oup t ial DDR link cannology shar e inf a han dfuion l ofisBRI in ided t er f aces. har dw ar ot ocols, invof olvpot ed en . Fu ndam ent al st ech or mat pr ov on Dialer face ion coms es in serv t wo ices, flav orins:clud dialer m apbased ( som et im r ed t oions as a b r oadintr er ang e ofconfig int egruralatsy st em and ing det ailed descr ipt ion s, es revrefer iew quest legacy iles. epional en dsr esou on t he cirfcu cesstuudy nder t o en suDDR) re conand ceptdialer comp pr r ehofen sionWhich and r m et et enhtod ion,you anduse ad d dit r ces ormfustrtan her . w hich you connect y . D ialer m apased DDR w as tf s, irstbut in talso r oduced inerI OS Ver sion 9 .0 ; Cov erag e isneed also dial ext end ed n ivit ot only t o new n etbwor k ing concep t o old , legacy dialer w in ere t r oduced in ic I OS Ver sion 1. 2. syst empr s,ofiles pr ovid g ainm or e r ealist pict ur e of t1he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Interesting Traffic The t er m int erest in g is used t o descr ibe pack et s or t r aff ic t hat w ill eit her t r igger a dial at t em pt or , if a d ial lin k is alr ead y act iv e, r eset t he idle t im er on t he d ialer int er face. For a packet t o be considered int er est ing , it m ust hav e t hese char act er ist ics:

The p acket m u st m eet t he " p er m it " cr it eria defined by an access list . The access list mu st be r efer en ced by t he dialer –list , or t he p acket m u st be of a pr ot ocol t hat is un iver sally p er m it t ed b y t he d ialer –list . The d ialer - list m ust b e associat ed wit h a dialer in t erf ace by use of a dialer gr oup. ev er ofaut om atsically con sid er ed t o be in t erest ing ( by d ef ault ) . I n t er est in g packet •Packet s ar e nTable Content •defin it ion s mIust ndexb e exp licit ly declar ed in a r out er or access serv er conf ig ur at ion. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Benefits and Drawbacks The b en ef it s of dialup ar e f lex ibilit y and cost saving s. Fir st , let 's look at w hy flexibilit y is im por t ant . I n t er m it t ent con nect iv it y is m ost of t en n eeded in mob ile sit u at ion s. A m obile w or kf or ce n eeds t o b e cap able of connect ing fr om w h er ever t h ey are. Ph one lines ar e nor m ally •av ailab le fr om Table of Content w her ever bus sin ess is t r ansact ed, so a m odem connect ion is t he on ly reasonable •choice for m ob I ndex ile u ser s. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

IByn Cisco lon g-Systems, dist anceInc. sit uat ion s, a user of t en dials int o a local I SP and uses an I PSec- en cr y pt ed t un nel goin g b ack t o a hom e gat ew ay syst em t h at allow s access t o t he r est of t he cor por at e net w or k. I n t h is ex am ple, t he phon e call it self cost s not hing , and an accou nt w it h t h e local I SP Pub lish er: Cisco Press could be signif ican t ly less exp en siv e t h an t he long - dist ance char ges t hat w ould ot her wise be Pub Dat e: Sep tem ber 1 1, 2 003 incur r ed . As anot her exam ple, a BRI at t ached at a cen t r al off ice locat ed in an ar ea t hat of fers I SBN:e1-r 58 inex pensiv at705 es -1 on19I-2SDN could hav e dat ab ase ser ver s conf ig ur ed t o call out t o ot h er sit es an d 11 28 exchanPages: ge d at a per iodically . Each sit e needs only on e BRI line, w h ich is significant ly less exp en siv e t h an d ed icat ed lin ks t o each of t he r em ot e locat ions. Finally , in t he case of a back up link , t he sav ings are seen w h en t h e pr imar y link goes dow n but bu siness cont inu es, alb eit slow er t han n orm al. Cost ings is a ion t w o-ofedg sw -ord w heralle dialup concern ed r, ef how ev er .p Th dowcover nsideage of aof The usav pdat ed edit t heedb est selling in- one isnet w ork ing erence roveides dialup line is t h at conn ect ion cost s for a heav ily u sed line ar e high er t han t he pr ice of d ed icat ed essent ial an d cu t t ing- edg e t ech nologies. connect ivit y . Goin g over long dist ance r aises t he pr ice even high er . Ther e'Con s also o consider. nectt ial iv it yt ohnas a stkr ong high - en d band art icular cisespeed ov er v tiew s of t echnDialup olog iescon essen et wor ing pr ofession als atwid allt h, levpels, f rom ly w it h tnov he capab ilit y t o t ie chann els t oget her using PPP m u lt ilink , b ut dedicat ed connect ivit y ice t o ex pert . t hr ou gh a serial p or t can out per for m d ialu p con nect ion s. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Anot h er con sid er at ion is secur it y . Cer t ainly, any PPP con nect ion shou ld b e aut hent icat ed, but t his pCov r esent s an yon e tw it hedge t he dialup nu m berlikan oppor y t okbing r eak in tst o or t hage e sy st em. A erag e of cut ing t echn ologies e opt icalt un n etitwor and signif icant par t of any dialup sy st em 's con figu rat ion concern s t he cap abilit y t o k eep out un w ant Aut ed h ored g uestby s. Cisco The good Sy st nems, ew s w isor t hldw at it idecan leader b e done, in netan w or d AAA king goes f or t he a lon I n tgerway n et . t ow ard dealing w it h t his pr ob lem . How ever , it is a disadv ant ag e t o h ave pot ent ial int ru ders com ing in t hr oug h I n t ern etlines. w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat dialup enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary Dialup t echnology has been arou nd for a long t im e, but only in t he last 20 year s or so h ave t he ph one lines been av ailable f or dialup net w or kin g. I n t hat t im e, a nu mb er of st an dar ds h ave been creat ed t o m ak e sur e t hat m odem s can com m unicat e pr op er ly w it h each ot her and w it h t he •syst em s t hat Table emp of loyContent t hem s. Cisco m oved int o t he access m ar k et w it h t he AS25 09 and AS251 1, •w hich used ext I ndex er nal analog mod em s, b ut Cisco cu rr ent ly pr od uces access ser ver s w it h cu t t ing Iedge nt e rn et w oral k ing Te chnologie s H a ndbook d igit m odem t echnolog y. , Four th Edit ion By Cisco Systems, Inc.

Cu rr ent dialup t ech nologies include t he v en er able POTS line as a low - cost and ub iq uit ous means of connect ing via m odem. To do t his, it uses a single chan nel, or DS0 . A st ep up fr om t h e POTS Pub lish er: Cisco Press line is t h e I SDN BRI lin e, wit h t w o DS0 ch annels and a D chan nel used for sign alin g. Get t ing u p Dat e: Sep tem ber 1 1, 2 003 t o inPub dust r ial- st reng t h lin es is t he T1/ E1. Th e T1 has 2 4 chan nels, and t he E1 h as 32 , alt houg h I SBN: 1-slot 58 705 19 -2 t he E1 uses 0 -1 for f r amin g an d slot 16 for call sign alin g. PRI ser vice is g ear ed t o allow I SDN 11 28ect , w h ile CAS w ill allow only asy nchr onou s calls in . client sPages: t o conn Mod em s t h em selv es hav e adv anced con sid er ably in r ecent year s t o t ake adv ant age of t he dir ect digit al con nect ion t h at t h e access ser v er m odems hav e t o t h e PSTN. This r esult s in V.9 0 connect ions t h at can t r ansfer dat a f rom t he serv er t o t he clien t at sp eeds up t o 5 3 k bp s. Because of analog conion ver sion onb est t he- selling an alog allline, r an sm ission fr om t h e client mides odemcover ar e age st ill of Thet he u pdat ed edit of t he in-t one net w orksing r ef erence p rov capable of on ly 33. 6 k bps. essent ial an d cu t t ing- edg e t ech nologies. Aft er a connect ion is est ablished, it ' s im por t ant t o h ave a r obust t r anspor t t o use t h e lin k. PPP fills t hCon at ncise eed.ovWit it sst hr p hase artessen u p—LCP, hent ion, and NCP—PPP adap s t o fitrom s er vhiew of eet echn ologst ies t ial t oaut n et woricat k ing pr ofession als at all levtels, env iron ment and can lear n it s connect ion in for m at ion w h ile sup por t ing a st r ong aut hent icat ion nov ice t o ex pert . sch em e. PPP can ex t en d a connect ion in t o a bun dle across m u lt ip le con nect ion s by u sin g PPP m ult ilink st eperbeyon d t hat ex t ending t h et ant PPPtm ult ilink y acr oss m ult iple chassis. New. A chapt s include coviserag e of im por opics likecapab VoI P ilit and EAP For lar ge inst allat ions, t his is in valuab le because user s g et t heir PPP mu lt ilin k session s w her ev er t he vacant Cov erag DS0s e ofare. cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Dial- onAutdhem ored an d byr out Cisco in gSy ( DDR) st ems, uses w ort ldw w o ide im por leader t ant in concep net wtor s: king t h e dialer f or t heand I n t er intner et est . ing t r aff ic. The d ialer is sim ply t h e int erf ace t hat is han dling t he r out in g an d con t rolling w het her a call is I n t ern et Iwntorerk est in ging Tech nologies , Four Ed it ion , is a as com refer t hator placed. t r af fic is t hHand e t r affbook ic t hat hast hb een defined w pr or ehensive t h br inging up ence t h e link enables w or k eepin g net it up forkin . g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry When t o. use Leardialup n how t tech o incor nology por is at ea int quest er net ionw of or kin usage g t echn pat tolog er n.ies I n in som t o ae LAN/ circum WAN st ances, env ir onm su chent as . Com w it h plet a meobile w it hendp new oint an d, ud pdat ialu ped is chapt t he only er s solut on secur ion tithat y , stwor illage, w or k. optAlso, ical net in cases w or k inwg, her scalabilit e y, anderspeed, int m it t en tt hconn is book ect ivis it ya is com need plet ede , an it dcan u p-be t o-md or at e rcost ef er-ence effecttiv o e. t he How t opev icsert,hat if conn are ect essen iv it tyialis t o all net w or kin needed m ost g p rof of essionals, t he t im e, dialup r egar dless m ay of become ex pert tise. he m or e cost ly alt er nat iv e. Speed is an ot her concer n : Dialup connect ions ar e n ot t y pically as fast as a d ed icat ed net w or k connect ion. Secu r it y Reader ill cer obtnain reatpersitun can be sa w con f ora dgialu esder as st wan ell.ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a bviously Ob r oad r ang , dialup e of int t echnology egr al sy st has em saand place serv t oday ices, at in clud t he ou ingt er deted ailed ge ofdescr t h e ipt netion w or s, k,rev p riew ovidin quest g ions t o en sutre access o tcon hose cept w ho comp need r ehiten fr sion om un and famr et iliar en tlocat ion, ion ands ad or dit f rom ional locat r esou ions r ces wh fer ore fu b et rt her t er tst echn udyologies . Cov ar e erag sim pelyisnot also available. ext end edWhenev n ot only er ttohenew n eed n etcalls wor kf ing or f lex concep ibilit yt s,orbut lowalso u t ilizat t o old ionerin , legacy a connect ion, syst emts, dialup echnologies pr ovid in g ashou m orlde be r ealist lookicedpict at ur ase aofvtiab he le realsoluwtor ion. ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: • •

How m any year s did it t ak e t h e t eleph one t o r each 90 per cent of t he hom es in t h e Table Unit edofStContent at es? s I ndex

I nt e rn et2 w:or k ing Te chnologie s Hraecom ndbook Four thions Edit ion Which V series m,endat pert ain

t o bit s p er second?

By Cisco Systems, Inc.

3:

How m any DS 0 s ar e in a BRI , T1, and E1m respect ively?

Pub lish er: Cisco Press

4:

What is t h e flow of d at a g oin g t hr ough a mod em fr om t h e RJ 11 t o t he DTE?

Pub Dat e: Sep tem ber 1 1, 2 003 I5 SBN: 1- 58 705ar -1 e 19t-2 : What he

t hr ee phases of PPP n eg ot iat ion? Wh y is t he ord er sign ificant ?

Pages: 11 28

6:

How d oes in t er est ing t r aff ic relat e t o t he idle t im er ?

7:

I s a BRI int er face a d ialer ? How w ould an asy nc int er face b ecom e a dialer ?

8 : edWhen is dialup ivit y allappr iatnet e t ow ork use? isn't itp rov ap pr opr cover iat e? age of The u pdat edit ion of t he connect b est - selling in-opr one ingWhen r ef erence ides essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Cisco Syst em s. Cisco I OS Dial Solut ions. I nd ianapolis: Cisco Pr ess, 1 998 . •

Table of Content s

•• ft p: / / f t p. cisco. com / p ub/ r f c/ RFC/ I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By • htCisco t p: / /Systems, hea- w w Inc. w . har var d. edu / ~

fine/ I SDN/ ov er v iew . ht m l

Pub lish er: Cisco Press

• ht tPub p: / Dat / isds. bus. lsu / ed u/ cvoc/ p roj ect s/ TechLibr ar y / CableI S/ hist ory . ht m l e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 11.28 • ht t p: Pages: / / www at t . com / h ist or y /

• ht t p: / / w w w . cisco.com / t ac/ The u pdat of tt ur hey.bcom est - /selling all-up inone netod w ork • ht t p: / / w wed w .edit digition alcen encyclo/ dat e/ cm em .ing ht mr lef hterence t p: / / w p wrov w . itides u. in cover t / it ud age oc/ itof uessent ial an d cu t t ingedg e t ech nologies. t / r ec/ v / Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 16. Synchronous Data Link Control and Derivatives • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Descr ibe t he hist or y of SDLC.

By Cisco Systems, Inc.

Descr ibe t he t y pes and t op olog ies of SD LC. Pub lish er: Cisco Press

Descr t heber f ram f orm at Pub Dat e: ibe Sep tem 1 1, e 2 003

of SDLC.

I SBN: 1- 58 705 -1 19 -2

Descr ibe d er iv at ive pr ot ocols of SD LC. Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction I BM d ev eloped t he Sy nchr onous Dat a Link Cont r ol ( SDLC) p r ot ocol in t h e m id- 19 70s f or u se in Sy st em s Net w or k Archit ect ur e ( SNA) en vir onm ent s. SDLC w as t he f ir st lin k layer pr ot ocol b ased on syn ch ron ous, bit - or ient ed operat ion . This chap t er pr ovid es a sum m ary of SD LC' s basic •oper at ional char Tableact of erist Content ics sand out lines sever al der ivat iv e p rot ocols. •

I ndex

IAft nt eer rn et w or k ing Te chnologie H a ndbook d ev eloping SDLC, I sBM su bm it, tFour ed itth tEdit o v ion ar ious st and ard s comm it t ees. The I nt er nat ional Or gan iz at ion f or St and ard izat ion ( I SO) m odified SDLC t o cr eat e t h e High- Lev el Dat a Link Cont r ol By Cisco Systems, Inc. ( HDLC) p r ot ocol. Th e I nt er nat ional Telecom m un icat ion Union–Telecom m un icat ion St and ard izat ion Sect or ( I TU- T; f orm er ly CCI TT) su bseq uent ly m odif ied HDLC t o cr eat e Lin k Pub lish er: Cisco Press Access Pr ocedu r e ( LAP) and t hen Link Access Pr ocedur e, Balanced ( LAPB) . The I n st it u t e of Pub Dat e: Sep tem ber 1 1, 2 003 Elect rical an d Elect r onic Engineers ( I EEE) m odified HDLC t o cr eat e I EEE 8 02. 2. Each of t hese I SBN: 1- 58 -1 19 pr ot ocols has b 705 ecom e-2im por t ant in it s dom ain, b ut SD LC r em ains t he pr im ar y SNA link lay er Pages: 28 pr ot ocol f or 11 WAN link s.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SDLC Types and Topologies SDLC sup por t s a var iet y of lin k t y pes and t opolog ies. I t can be used w it h point - t o- point and m ult ipoint link s, boun ded an d unb ounded m ed ia, half - dup lex an d f ull- du plex t ran sm ission facilit ies, an d cir cuit - swit ched and pack et - sw it ched net w or ks. •

Table of Content s

•SDLC ident if ies I ndex t w o t y pes of net w or k nod es: pr imar y an d secon dar y . Pr im ar y nod es con t rol t he Ioper nt e rnat etion w or of k ing chnologie s H acalled ndbook second , Four th aries. Edit ion The p rim ar y polls t h e second aries in a otTe her st at ions, pr edet erm ined or der, and secondar ies can t hen t r an sm it if t h ey hav e out g oin g d at a. Th e pr imar y By Cisco Systems, Inc. also set s up and t ear s dow n lin ks and m anages t h e lin k w hile it is op er at ional. Secon dar y nod es ar e cont r olled by a pr im ary , w h ich m ean s t hat second ar ies can send inf or mat ion t o t he p r im ar y Pub lish er: Cisco Press only if t h e pr imar y g ran t s per m ission. Pub Dat e: Sep tem ber 1 1, 2 003 1-ies 58 705 -1 19secondar -2 SDLC pI SBN: rim ar and ies can b e connect ed in fou r basic conf ig ur at ions: Pages: 11 28

Point - t o- p oi nt — I n volv es only t w o nodes, one p rim ar y and one secondar y . Mu lt i poi nt — I n volv es one p rim ar y and m ult iple secon dar ies. The uLoop pdat ed iones of at he b est - selling, allw ork ing rect ef erence — edit I n volv loop t opology w it hin-t hone e prnet imar y conn ed t o t hperov fir ides st ancover d lastage of essentsecond ial an darcu t t ingedg e t eche nologies. ies. I nt er mediat secondar ies pass m essages t h rou gh one an ot her as t h ey r espond t o t he r equest s of t he pr im ar y . Con er vaiew t echn essen t ial to n k ing ofession els,t hf rom H ubcise go-ov ahe d—s Iof n volv es olog an inies boun d an d an ouett wor boun d chpr annel. Theals pr at im all ar ylev u ses e nov ice t o ex pert . out b ound chan nel t o com m unicat e w it h t he secondar ies. The second ar ies u se t he inb ound chann el t o com m unicat e w it h t he p rim ar y. The inb ound chan nel is daisy- ch ain ed b ack t o New cov erag e of t he prchapt imar er y tshinclude rou gh each secon darim y.por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SDLC Frame Format The SD LC fr am e is show n in Figur e 16 - 1.

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Table of Content s

•

I ndex Figu r e

1 6 -1 . Six Fie lds Com pr ise t h e SD LC Fr am e

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net kin gipt p rions ofessionals unt he derst and an dst rim t cont em- por The f ollow inwgor d escr sum m art oize f ield s illu atplem ed inen Figur e 16 1: ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Flaeg— iat es t er med inat es ererror ch eck ing. Com plet w itIhn itnew anan d du pdat chapt s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Ad dre Cont ains rt he SDLC ess ofise. t he secon dar y st at ion, w hich indicat es w het her net w or kin g pss— rof essionals, egar dlessaddr of ex pert t he fr am e comes f rom t he p rim ar y or secon dar y. This add ress can con t ain a specif ic add ress, a ain g roua pg ad drer ess, dr ess. A pr imar y or is keit herp ar a com m un Reader sw ill obt reat un or derastbr anoadcast ding of ad LAN and WAN n et w ing, t icu lar ly icat t h e ion a d est inat hichinv elim t he n eed in clu de t heinf addr ession of is t heprpov rim ar y.on har dwsour ar e,cepror ot ocols, and ion ser,vwices olv inat ed . es Fu ndam ent alt ot ech nology or mat ided a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Cont rol — Emcomp ploy sr eh t hren eesion diff erent for at s, and depend ingional on trhe t y pe of f SD LCrt frher amst e udy used: t o en su re con cept and r et enmt ion, ad dit esou r ces or fu . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy - I nf orm a t ion ( I ) f ra m e— Car ries up per - lay er inf orm at ion and som e cont r ol syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich inf orm at ion. This f ram e sends and receiv es seq uence num b er s, and t h e poll f inal pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease ( P/ F) b it per for m s f low and err or cont rol. Th e sen d sequence n um ber r ef ers t o t h e pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient nu mb er of t he f ram e t o be sent nex t . The r eceiv e seq uence num b er pr ovides t h e decisions for t h eir net w ork s. nu mb er of t he f ram e t o be receiv ed n ex t . Bot h sender an d r eceiv er main t ain send and r eceive sequ en ce num ber s.

A p r im ar y st at ion uses t he P/ F b it t o t ell t he secon dar y w het her it requ ires an im mediat e response. A secondar y st at ion uses t he P/ F bit t o t ell t he p r im ar y w het her

t he cu rr ent fr am e is t he last in it s cu rr ent respon se. - Su per v isory ( S) fr am e — Prov ides cont r ol inf or m at ion . An S f r ame can r eq uest and suspend t r ansm ission, r epor t on st at u s, and ack now ledg e receip t of I f r am es. S fr am es do not hav e an in for m at ion field .

• •

- U nnum be re d ( U) fr am e — Supp ort s con t r ol pur p oses and is n ot sequenced. A U fr am e can be u sed t o init ialize secon dar ies. Depend ing on t he f unct ion of t he U fr Table am e,ofit Content s cont rsol f ield is 1 or 2 by t es. Some U fr am es hav e an in for m at ion field . I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

D a t a— Cont ains a pat h in for m at ion u nit ( PI U) or ex chang e ident ificat ion ( XI D) in for m at ion.

By Cisco Systems, Inc.

Fra m e ch eck se que nce ( FCS) — Preced es t he end in g flag delim it er and is usu ally a cyclic ed und ancyPress check ( CRC) calcu lat ion r emain der. The CRC calculat ion is redon e in t he Pubr lish er: Cisco r eceiver . I f t he r esult d if fer s f rom t he v alue in t he or igin al fr am e, an er r or is assum ed . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 A t yp ical SD LC- b ased net w or k configu r at ion is show n in Figur e 16 - 2. As illust r at ed, an I BM Pages: 11 28cont r oller ( for m er ly called a clust er cont r oller ) in a r em ot e sit e connect s t o dum b est ablish ment t er min als and t o a Token Ring net w or k . I n a local sit e, an I BM host conn ect s ( v ia chan nelat t ached t ech niques) t o an I BM f ron t - end pr ocessor ( FEP) , w h ich also can h ave lin ks t o local Tok en Rin g LANs and an SNA back bone. Th e t w o sit es ar e connect ed t h rou gh an SDLC- based 56 k bps leased line. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r e 1 6 -2 . An SD LC Lin e Li nk s Loca l an d Re m ot e Si t e s ove r a Ser i al Con cise ov er v iew s of t echn olog ies essen tLi ialne t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Derivative Protocols Despit e t h e fact t hat it om it s sev eral feat ur es used in SDLC, HDLC is generally consider ed t o be a com pat ible super set of SDLC. LAP is a sub set of HDLC and w as cr eat ed t o ensu re on going com pat ibilit y w it h HD LC, w hich h ad b een m odified in t h e ear ly 1 980 s. I EEE 802 .2 is a •m odificat ion Table of Content s of HDLC for LAN env ir onm ent s. Qu alified Logical Link Con t r ol ( QLLC) is a link lay er •pr ot ocol d ef ined I ndexb y I BM t h at enab les SNA dat a t o be t r anspor t ed acr oss X.2 5 net w ork s. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

High-Level Data Link Control Pub lish er: Cisco Press Pubsh Dat e: Sep ber 1 1,e 2for 003m at of SDLC, and HDLC f ields p r ovide t he sam e fu nct ionalit y as t h ose HDLC ares t htem e fr am I SBN: 158 705 -1 19 -2 in SDLC. Also, as in SD LC, HD LC suppor t s sy nchr onou s, fu ll- d uplex oper at ion. Pages: 11 28

HDLC d if fer s f rom SDLC in sev er al m inor way s, how ev er . Fir st , HDLC has an op t ion f or a 32- b it check sum . Also, un lik e SDLC, HDLC does not su ppor t t he loop or h ub go- ahead config ur at ions. The m aj or dif fer en ce b et ween HDLC and SDLC is t h at SD LC su ppor t s on ly one t r ansf er mod e, w her eas HD LC suppor t s t hr ee: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. N or m a l re sponse m ode ( N R M) — This t r ansfer m ode is also used by SDLC. I n t h is m ode, second ar ies cann ot com m unicat e w it h a pr im ar y unt il t he p rim ar y has g iven per mission . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert Asy nchronou s .re sponse m ode ( AR M) — This t r ansfer m ode en ables secondar ies t o init iat e com m unicat ion wit h a pr imar y w it hou t r eceiv ing perm ission . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Asy nchronou s ba la nced m ode ( A BM) — ABM int r od uces t he com bined node, w hich can Cov erag t echn lik e gopt et wor k ingAll and st orcom agemu nicat ion occur s act as a eprof imcut aryt ing or aedge secon dar yologies , dependin onical t h ensit uat ion. ABM bet w een m ult iple com bined nod es. I n ABM env ir onm en t s, any com bined st at ion can init iat e Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . dat a t r ansm ission wit h out perm ission f rom any ot h er st at ion . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. MastProcedure, Link-Access er t he t er m s, con Balanced cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w itkhnow newn an ed chapt s on secur y , st or age, opt ical w or g, scalabilit LAPB is best ford ituspdat pr esence in er t he X. 25 pr otitocol st ack . LAPB shnet ares t hkeinsame fr am e y, andmspeed, t h ist yp book is ad com e an d uas p- tSDLC o- d at e r ef HDLC. er ence Unlik t o t he t ophics t hat are essen t ial for at , f r ame es, an fieldplet f unct ions and e eit er of t hese, h ow ev er,t o all net w oriskin gp rofed essionals, r egar dless ofmex pert LAPB r est r ict t o t he ABM t r ansfer ode anise. d is appr opr iat e only f or com bined st at ion s. Also, LAPB cir cuit s can be est ablished b y eit h er t he d at a t er m in al equip ment ( DTE) or t h e dat a cir cuit Reader s in wg ill eq obt ain a g reat er .unThe der st st an dinginit ofiat LAN WANisndetetwerormk ined ing, pt oarbe t icut he lar ly h ear y, and t er min at uipm ent ( DCE) at ion ing and t he call pr tim har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov t he respond ing st at ion is t h e second ary . Finally , LAPB use of t he P/ F bit is som ew hat d iffided er enton a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions fr om t hat of t he ot h er p r ot ocols. For det ails on LAPB, see Ch apt er 17 , " X. 25 . " t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich IEEE 802.2oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr of essionals pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions eirennet s. t o as t h e Log ical Link Con t r ol ( LLC) . I t is ex t r emely pop ular in LAN I EEE 8 02. for 2 ist hoft r efwerork r ed env iron ment s, wh er e it int erop er at es w it h pr ot ocols such as I EEE 802 . 3, I EEE 8 02. 4, and I EEE 80 2. 5. I EEE 802 .2 of fer s t hr ee t y pes of ser v ice. Ty pe 1 pr ov ides unack now ledged con nect ion less serv ice, w h ich m eans t hat LLC Typ e 1 does not conf ir m d at a t r an sf er s. Because m any up per- lay er pr ot ocols, su ch as Tr an sm ission Con t rol

Pr ot ocol/ I n t er net Pr ot ocol ( TCP/ I P) , of fer r eliab le dat a t ran sf er t hat can com pensat e f or un reliable low er - lay er pr ot ocols, Typ e 1 is a com mon ly used serv ice. Ty pe 2 pr ov ides con nect ion - or ient ed ser v ice. LLC Ty pe 2 ( oft en called LLC2) ser v ice est ablishes logical connect ions b et w een sender an d receiv er and is t her efor e connect ion- or ien t ed . LLC2 ackn ow ledg es dat a upon r eceipt and is used in I BM com m unicat ion sy st ems. Ty pe 3 pr ov ides ack now ledg ed connect ionless ser vice. Alt houg h LLC Ty pe 3 ser v ice su ppor t s • Table of Content s ackn ow ledg ed d at a t r ansf er , it does not est ab lish logical connect ions. As a com pr om ise bet w een •t he ot her t w oI ndex LLC ser v ices, LLC Ty pe 3 is u sef ul in fact or y - aut om at ion en vir onm ent s wh er e er r or Idet nt eect rn etion w oris k ing chnologie a ndbook th Edit im Te por t ant bust Hcont ex t ,stFour or age sp ion ace ( for v ir t ual cir cu it s) is ext r em ely lim it ed . By Cisco Systems, Inc.

En d st at ion s can sup por t m ult ip le LLC ser v ice t yp es. A Class I dev ice su ppor t s on ly Typ e 1 ser vPub ice. A Class I I dev ice sup por t s bot h Ty pe 1 an d Ty pe 2 serv ices. Class I I I dev ices sup por t lish er: Cisco Press bot h Ty pe 1 an d Ty pe 3 serv ices, an d Class I V devices supp ort all t hr ee t y pes of ser v ice. Pub Dat e: Sep tem ber 1 1, 2 003

SBN: 1-p58 705 -1 19 -2use I EEE 8 02. 2 ser v ices t h rou gh ser v ice access p oint s ( SAPs) . Th e I EEE Upper -Ilayer rocesses 11 28 80 2. 2 Pages: header begins w it h a dest in at ion ser vice access point ( DSAP) field, w hich ident ifies t h e r eceivin g u pper - layer p rocess. I n ot her w or ds, af t er t he r eceiv ing node' s I EEE 80 2. 2 im plem ent at ion com plet es it s pr ocessin g, t h e up per- lay er pr ocess ident if ied in t he D SAP f ield r eceives t h e r em aining d at a. Follow ing t h e DSAP ad dr ess is t he sour ce ser v ice access p oin t ( SSAP) addr ess, w h ich ident ifies t h e sen ding upp er - lay er pr ocess.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Qualified Logical Link Control Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom QLLC nov pr ovid t hepert dat. a- lin k cont r ol capabilit ies t hat ar e requ ired t o t ran sp ort SNA d at a acr oss ice es t o ex X. 25 net w or ks. Tog et h er , QLLC an d X. 25 r eplace SDLC in t he SNA pr ot ocol st ack . QLLC uses t he pack et - lev chapt el layer of erag t h e X.2 pr por ot ocol . To indicat t h atEAP a Lay er 3 X. 2 5 p ack et New er s( Layer include3 )cov e of5 im t antstt ack opics like VoI Peand m ust b e han dled b y QLLC, a sp ecial b it called t he qualifier bit , in t h e gener al for m at id en t ifier ( GFI ) Cov of terag h e Lay er cut 3 X.2 packet - level h ead er setical to n 1.etThe at a stisorcar r ied as user dat a in e of t ing5 edge t echn ologies lik, eisopt wor kSNA ing dand age Lay er 3 X. 25 packet s. For m or e infor m at ion about t he X.2 5 p r ot ocol st ack , see Ch apt er 17 . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary The SD LC pr ot ocol w as dev elop ed by I BM in t he m id- 1 970 s for u se in SNA en vir onm ent s. SDLC w as t h e fir st link - layer p rot ocol based on syn ch ron ous, bit - or ient ed operat ion , and it r em ains t he pr im ary SNA link lay er pr ot ocol for WAN link s. •

Table of Content s

•SDLC sup porItndex s a var iet y of lin k t y pes and t opolog ies. I t can be used w it h point - t o- point and Im ntult e rnipoint et w or klink ing s, Te chnologie a ndbook , Four th Edit ionia, half - dup lex an d f ull- du plex t ran sm ission boun deds Han d unb ounded m ed facilit ies, an d cir cuit swit ched and pack et sw it ched net w or ks. By Cisco Systems, Inc.

SDLC ident if ies t w o t y pes of net w or k nod es: pr imar y an d secon dar y . Pr im ar y nod es con t r ol t he Press operPub atlish ioner:ofCisco ot her st at ions, called second aries. Pub Dat e: Sep tem ber 1 1, 2 003

SDLC pI SBN: rim ar 1-ies 58 705 and -1 19secondar -2 ies can b e connect ed in fou r basic conf ig ur at ions: p oin t - t o- p oin t , m ult ipoint , loop, an d h ub goah ead . Pages: 11 28 The f ollow in g p r ot ocols ar e d er iv at ives of SDLC: HDLC, w hich su ppor t s t hr ee t ran sf er m odes, wh ile SDLC supp ort s only one The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essentLAPB, ial an wh d cu ich t t ingis r est edgr ict e ted echt onologies. t he ABM t r ansf er m od e and is app rop riat e only for com bin ed st at ions Con ov2,er wh v iew t echn n et hwor als at all lev els, f rom I EEEcise 8 02. ichs of is of t en rolog eferies redessen t o ast ial LLCt oand as kt ing hr eeprt ofession y pes nov ice t o ex pert . QLLC, wh ich pr ov ides t he d at a- link cont r ol capab ilit ies t h at ar e r equir ed t o t r anspor t SNA Newa chapt erX. s include e of im por t ant t opics like VoI P and EAP dat across 25 n et w cov or k erag s Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

Nam e t w o of t h e link t y pes t h at SDLC sup por t s.

2:

I ndexe t he f our basic SDLC connect ion conf igur at ions. Nam

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

: HowInc. m any By Cisco 3 Systems, 4:

field s does t h e SDLC f ram e h ave, an d w h at ar e t hey ?

List t he der ivat iv e p rot ocols of SDLC, an d d escr ib e t heir pr im ar y diff erence( s) f rom SDLC.

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 17. X.25 Obj e ct i ve s • •

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Discuss t he h ist or y an d d ev elopm en t of t h e X. 25 pr ot ocol. I ndex

I nt e rn Descr et w or kibe ing Te chnologie H a ndbook , Four th Edit t he basic fsunct ions an d com ponion en t s

of X. 25.

By Cisco Systems, Inc.

Descr ibe t he f ram e f orm at s of X.2 5. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction X. 25 is an I nt er nat ion al Telecom mu nicat ion Union– Telecomm u nicat ion St an dar dizat ion Sect or ( I TU- T) pr ot ocol st and ar d f or WAN com m un icat ions t hat defines how connect ions bet w een u ser dev ices and n et w or k dev ices ar e est ablish ed an d m aint ain ed . X. 25 is desig ned t o oper at e •eff ect iv ely r egar Table of Content s t y pe of sy st em s conn ect ed t o t h e net w or k. I t is t y pically used in t he dless of t he •pack et - sw it ched I ndexnet w ork s ( PSNs) of com m on car r ier s, such as t he t elephon e comp anies. ISub nt e rn etibers w or k ing chnologie H a ndbook Four th Editof ion scr areTech arg ed sbased on ,t heir use t he n et wor k . The developm ent of t he X. 25 st andar d w as init iat ed by t h e com m on carr iers in t h e 197 0s. At t hat t ime, t here w as a need for By Cisco Systems, Inc. WAN p r ot ocols capab le of pr ov id ing con nect iv it y acr oss pub lic d at a n et w or k s ( PDNs) . X. 25 is nowPub adm inist er ed as an in t ern at ional st and ard b y t he I TU- T. lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

X.25 Devices and Protocol Operation X. 25 net w or k devices fall in t o t h r ee g en er al cat egor ies: dat a t erm inal eq uipm ent ( DTE) , d at a circuit - t er m inat ing equipm ent ( DCE) , and p ack et - swit chin g ex change ( PSE) . D at a t er m in al equipm ent dev ices ar e end sy st ems t hat com m un icat e acr oss t he X. 2 5 n et w or k . They ar e usu ally •t er min als, p er Table of Content sonal com pust er s, or n et wor k h ost s, and are locat ed on t he pr em ises of ind iv idu al •subscr ib er s. DCE I ndex d ev ices are com m unicat ions devices, such as m odem s and pack et sw it ch es, It hat nt e rnpr etov w or k ing a ndbook Four th Edit ion and a PSE, an d ar e g en er ally locat ed in t he ide t hTe e chnologie int erf aces Hbet w een , DTE dev ices carr ier 'sSystems, f acilit ies. By Cisco Inc.PSEs ar e sw it ch es t hat com pose t h e bulk of t he car rier 's n et w or k . They t r ansfer d at a f rom one DTE d ev ice t o an ot her t hr oug h t he X. 25 PSN. Figur e 17 - 1 illust r at es t he r elat ion sh ip s am ong t he t hr ee t yp es of X. 2 5 n et w or k d ev ices. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 1 7 -1 . D TEs, D CEs, an d PSEs M ak e Up a n X.2 5 Ne t w or k

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Packet Assembler/Disassembler indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, The pack et assem bler / d isassem bler ( PAD) is a dev ice com m only f ound in X.2 5 n et wor k s. PADs and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all ar e used w h en a DTE device, such as a char act er - m ode t er m inal, is t oo sim ple t o im plement t he net w or kin g p rof essionals, r egar dless of ex pert ise. fu ll X. 25 fu nct ionalit y. The PAD is locat ed bet w een a DTE device and a DCE dev ice, an d it per for msswt ill hr ee imaargyreat funer ct ion s: bu ff erding ing (of st or ingand dat aWAN unt iln et aw dev is p r eady o pr Reader obtpr ain un der st an LAN or kice ing, ar t icut lar lyocess t h e it ) , pack et assem bly , and pack et disassem bly . The PAD b uff ers d at a sent t o or fr om t h e DTE device. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Iat balso assemb les ou t going dat a int o packet s an d for w ard s t hem t o t he DCE dev ice. ( Th is r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions includes ding ancomp X.2 5r header. ) Finally the PADand d isassem b les rincom befor e . t o en su readcon cept eh en sion and r et, en t ion, ad dit ional esou r ing ces pack f or fuetrtsher st udy for w ar ding t h e dat a t o t h e DTE. ( This includ es r em oving t h e X. 25 header .) Figur e 17 2 illust r at es Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy tsyst he basic operat ion of t h e PAD w h en r eceivin g p ack et s f rom t he X. 25 WAN. em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figu r e 1 7 -2 . Th e PAD Buf f er s, Assem b le s, a n d D isasse m bl es D at a Pack et s

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

X.25 Session Establishment X. 25usessions ar eion estof ablish w-hen oneallDTE ev ice t act s anot h er t o pr rov equest com age m unof icat ion The pdat ed edit t he ed b est selling in-done netcon w ork ing r ef erence ides acover session. Th e DTE device t h at r eceiv es t he r equest can eit h er accept or r ef use t he con nect ion . If essent ial an d cu t t ing- edg e t ech nologies. t he requ est is accept ed, t he t w o sy st ems begin full- du plex infor m at ion t r ansfer . Eit her D TE dev ice can t erm inat e t he conn ect ion. Aft er t h e session is t er m in at ed, any fur t h er com m un icat ion r eq uirCon es tcise he est a new session. ovablish er v iewms en oft tof echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . chapt er s include cov erag e of im por t ant X.25New Virtual Circuits

t opics like VoI P and EAP

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Av ir t ual circuit is a logical connect ion cr eat ed t o ensur e r eliable com m unicat ion bet w een t w o net w or k hdev ices. v ir t ual cu it denot eside t heleader exist ence ofwaorlog ical, irect Aut ored by ACisco Sy cir st ems, w or ldw in net king f orb id t he I n tional er n etp. at h fr om one DTE dev ice t o anot h er acr oss an X. 25 net w or k. Phy sically , t he connect ion can pass t h r ough any Inu n tmb erner et woforink tinerm g Tech nologies Four t h Ed it ion a com refer ence hatical ediat e n odes,Hand su chbook as D, CE devices and, is PSEs. Muprltehensive iple v ir t u al cir cuit s (tlog enables net w or kinbe g pmr ofessionals t ot ounaderst and ansical d im cir plem em por ar y intion) er net w ork ing connect ions) can ult ip lex ed on sin gle phy cuiten( ta cont ph ysical connect . Vir t ual tcircuit echnologies. Mast t heedt er s, con t echn ologies, d devices in tiat oday ' s net w ork ing s are d em u lt er ip lex atmt he remcep ot et s,end, and dat a isansent t o t he used ap pr opr e dest inat ions. indu stery17 . Lear n how t o fou incor porarat at e eintvir ertnet orcuit kin g in ted o aont LAN/ env ir onm Figur - 3 illust r at es r sep ual wcir s bt echn eing olog m ulties iplex o aWAN sing le phy sicalent . Com plet circuit . e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader a rgtreat un der LAN n etdw ont or k ing, icu lar t h e si ca l Figu rs ew ill 1 7obt -3ain . Vi u alerCir cu st it an s ding Ca n ofBe M and ul t iWAN ple xe o ap ar Sit ngl elyPhy har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Cir cu it a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Tw o t y pes of X. 25 v irt ual cir cu it s ex ist : sw it ched an d perm anent . Sw it ch ed v ir t ual circuit s ( SVCs) ar e t em por ary con nect ion s used f or spor adic dat a t r ansfer s. They r equir e t hat t w o D TE d ev ices est ablish , m ain t ain, an d t er m inat e a session each t im e t h e dev ices need t o com mu nicat e. Perm an en t v ir t u al cir cu it s ( PVCs) ar e p er m anent ly est ablished conn ect ions used f or fr equent and consist ent dat a t r ansfer s. PVCs d o not r eq uir e t hat sessions be est ablished and t er m inat ed. Ther ef or e, DTEs can begin t r ansfer rin g d at a w h en ev er necessary becau se t he session is alw ay s act ive. •

Table of Content s

•The b asic operat I ndexion of an X. 25 vir t ual cir cuit begins w hen t he sou rce DTE d ev ice sp ecifies t h e Ivnt or k ing t Te chnologie H a ndbook , Four th Edit ion irteurnalet w circuit ob e used s( in t h e packet header s) and t hen sen ds t h e packet s t o a locally connect ed D CE device. At t his point , t he local D CE device exam ines t h e pack et header s t o By Cisco Systems, Inc. det er min e w hich v ir t ual cir cu it t o use and t hen sen ds t h e packet s t o t h e closest PSE in t h e pat h of t hat v irt u al circuit . PSEs ( sw it ch es) pass t he t raf fic t o t h e next int er mediat e node in t he pat h, Pub lish er: Cisco Press w hich may be anot h er sw it ch or t he rem ot e DCE d ev ice. Pub Dat e: Sep tem ber 1 1, 2 003

SBN:t raf 1- 58 -2 at t he rem ot e DCE d ev ice, t he pack et header s ar e exam ined and t he When tI he fic705 ar-1r 19 ives Pages: 28 ess is det erm ined. The pack et s ar e t hen sent t o t he dest inat ion DTE dev ice. I f dest inat ion 11 addr com mu nicat ion occur s ov er an SVC and n eit her d ev ice has ad dit ional d at a t o t r ansfer , t he vir t ual circuit is t erm inat ed.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

The X.25 Protocol Suite The X. 2 5 p rot ocol su it e m aps t o t he low est t hr ee lay er s of t h e OSI r efer en ce m od el. Th e follow ing pr ot ocols ar e t y pically u sed in X.2 5 im plem en t at ions: Pack et - Lay er Prot ocol ( PLP) , Link Access Pr ocedu r e, Balan ced ( LAPB) , and t hose am ong ot her p hy sical- layer serial in t erf aces ( such •as EI A/ TI A- 23 Table ofA/ Content 2, EI TI A- 4s49, EI A- 530 , and G. 70 3) . Figur e 17 - 4 m ap s t he k ey X. 25 pr ot ocols t o •t he lay er s of Itndex he OSI r ef er ence m odel. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r eer: 1Cisco 7 -4Press . Key X.2 5 Pr ot ocols M a p t o t h e Thr e e Low er La ye r s of t h e Pub lish O SI Ref e r en ce M ode l Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Packet-Layer Protocol and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. PLP is t he X. 25 net w or k layer p rot ocol. PLP m anag es packet ex chang es b et ween DTE devices Reader reat eralso un der LAN and WAN ing, )p im ar tplement icu lar ly at t hions e across vs irwt ill ualobt cirain cu itas.gPLPs canstran unding overofLogical Link Contnret olw2or(kLLC2 on har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on LANs an d over I nt egr at ed Ser v ices Dig it al Net w ork ( I SDN) int er faces r unnin g Link Access a r oad rreang of int al sy em s and Prbocedu onet he D egr chann el st ( LAPD) . serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . The PLP eopiseralso at esext in end fiv eed dist inctonly m odes: calln et set up,k ing dat aconcep t r ansfer idle, callt oclear in,g,legacy an d Cov erag n ot t o new wor t s, ,but also old er rsyst est ar . ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich emt ing s, pr pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Call set est ablish help SVCs bett he w een DTEm dev ices. u ses t h, ecost X. 121 pr odu ctup iv it m y ode an d is imuprsed ov et oeff iciency, ing r eader ake morAe PLP in t elligent - eff icient add ressin gforschem t o wset decisions t h eir enet orkus.p t he v irt ual cir cu it . The call set up m ode is ex ecut ed on a per - v ir t u alcircuit basis, w hich m eans t h at on e vir t ual cir cuit can be in call set up m ode w hile anot her is in dat a t r ansfer m ode. Th is mod e is used only w it h SVCs, not wit h PVCs. Dat a t r ansfer m ode is u sed for t r ansfer ring d at a b et w een t w o DTE dev ices across a v ir t u al circuit . I n t h is mod e, PLP hand les segm en t at ion and r eassem bly , b it pad ding, and err or an d f low cont r ol. This m od e is ex ecu t ed on a per- vir t ual- circu it basis and is u sed w it h b ot h PVCs and

SVCs. I dle m ode is u sed w hen a v irt u al circuit is est ab lish ed bu t d at a t r ansf er is not occur r ing. I t is execut ed on a per - vir t u al- cir cu it b asis an d is u sed only w it h SVCs. Call clearin g m od e is used t o end com m un icat ion sessions bet w een D TE d ev ices an d t o t er m in at e SVCs. Th is mod e is execut ed on a per - vir t ual- cir cu it basis an d is u sed only w it h SVCs. •Rest ar t ing mod Table of used Content e is t os syn chr onize t r ansm ission bet w een a DTE d ev ice and a locally •connect ed D CE I ndex device. This m ode is not ex ecu t ed on a p er - v ir t ual- cir cuit basis. I t aff ect s all t he IDTE nt e rndev et w ice's or k ingest Teab chnologie H atndbook Four lished svir ual cir ,cuit s.th Edit ion By Cisco Systems, Inc.

Four t y pes of PLP pack et f ields ex ist : Pub lish er: Cisco Press Pub Dat e: rSep ber 1a1, 003nt i fi er Gene al tem Form t I2 de

( GFI ) — I d en t ifies pack et par am et er s, such as w het her t he pack I SBN:et1-carr 58 705 ies -1 19 user -2 dat a or cont r ol inf or m at ion , w hat k in d of w in dow ing is being used , and wPages: het her d eliv er y conf irm at ion is r eq uir ed . 11 28 Log ical Cha nne l I de nt i fi er ( LCI ) — I d en t ifies t he v ir t ual cir cuit acr oss t he local DTE/ DCE int er face.

P ack e t Ty pe I de nt i fi er ( P TI ) — I d en t ifies t he p ack et as one of 17 d if fer en t PLP p ack et The utpdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of y pes. essent ial an d cu t t ing- edg e t ech nologies. U se r D at a — Cont ains en cap su lat ed u pper - layer inf or mat ion . This f ield is pr esent only in dat a pack et s. Ot her wise, add it ion al f ields cont ain ing con t r ol inf orm at ion ar e added. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

LinkNew Access Balanced chapt erProcedure, s include cov erag e of im por t ant

t opics like VoI P and EAP

of cut edge t echn lik e com opt ical n et wor st or fr age LAPB Cov is aerag dat ae link layt ing er pr ot ocol t hatologies m anages mu nicat ionk ing an dand packet am in g bet w een DTE and DCE d ev ices. LAPB is a bit - or ien t ed p rot ocol t hat ensu res t h at f ram es ar e cor rect ly or dered Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . and er ror - f ree. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Thr ee t y pes of LAPB fr am es ex ist : inf or mat ion , super visor y, and unn um ber ed . The in for m at ion enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing fr am e ( I - f ram e) car r ies u pper - layer inf or mat ion an d som e cont r ol inf or mat ion . I - fr am e f unct ions t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing include sequ en cing , f low con t r ol, and err or d et ect ion and recov er y . I - fr am es car r y send- and indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . r eceive- sequence nu mb er s. Th e su per visor y fr am e ( S- fr am e) car r ies cont r ol in for m at ion. SCom plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, fr am e f unct ions in clu de r eq uest in g and su sp en ding t r ansm issions, r epor t ing on st at us, and and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all ackn ow ledg ing t he r eceipt of I - fr am es. S- f r am es car r y only r eceive- sequence nu m bers. Th e net w or kin g p rof essionals, r egar dless of ex pert ise. un num ber ed f r ame ( U fr am e) carr ies cont r ol inf or mat ion . U- fr am e fu nct ions include lin k set u p and disconnect ion, as well as er r or r ep ort in g. U f r ames car r y no sequ en ce n um ber s. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su The X.21bis re con cept Protocol comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst emiss,ispra ovid in g a layer m or eprrot ealist ic used pict urine of t het hat real-defines w or ld nt hetewelect or k ing enan virdonm ent s in w hich X. 21b ph ysical ocol X. 25 r ical mechanical pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill pr oced ur es for u sin g t he ph ysical m ed ium . X. 21b is hand les t he act ivat ion an d d eactincr iv atease ion of t he pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient ph ysical m ed ium conn ect ing DTE and DCE d ev ices. I t su ppor t s point - t o- p oint con nect ion s, decisions h eir2 net w ork speed s upfor t o t19. k bps, ans. d sy nchr onous, f ull- du plex t r ansmission ov er fou r- wir e m edia. Figur e 17 - 5 sh ows t he f orm at of t he PLP p ack et an d it s relat ionship t o t h e LAPB fr am e and t he X.2 1bis fr am e.

Figu r e 1 7 -5 . Th e PLP Packe t I s En ca psul at e d W it h in t he LAPB Fr am e a nd t h e X.2 1 bis Fr am e

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

LAPB Frame Format LAPB fr am es inclu de a header, en cap su lat ed d at a, and a t railer . Figur e 17 - 6 illust r at es t he for m at of t he LAPB fr am e and it s r elat ionship t o t h e PLP packet and t he X. 2 1bis f ram e. •

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Figu r e 1 7 -6 . An LAPB Fr a m e I n cl ude s a He a der , a Tr a il er , an d Encapsu la t ed D at a

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables The f ollow net inwgor d escr kin gipt p rions ofessionals sum m art oize unt he derst f ield and s illu an dst rim atplem ed inen Figur t cont e 17 em- por 6: ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Flaeg— s t hd eu beginn g anderen d ofsecur t he itLAPB fr am e. opt Bit ical st ufnet fingw is sed o ensur ey,t h at Com plet w itDelim h newit an pdat edinchapt s on y , st or age, or ku in g, tscalabilit t he flag pat t er n does not occur w it h in t he bod y of t he f r ame. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Ad dre ss— I n dicat es wh et her t he f r ame car r ies a com man d or a r esp onse. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e —ocols, Qualifies anolv d response f r ames d ind icat es et h er f ram e is an har dwCont ar e, rol pr ot and com ser vman ices dinv ed . Fu ndam ent al an t ech nology infworh mat iont he is pr ov ided on I fr am e, an Sfr am e, or a Uf ram e. I n addit ion, t his f ield cont ains t h e fr am e's sequence a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions nure mbcon er cept and itcomp s fu nct ( for ex amr et ple, het her eceiver - r ead y orr ces disconnect ) . Con t r ol. t o en su r ehion en sion and en twion, and rad dit ional r esou f or fu rt her st udy fr am es v ary in lengt h d ep en ding on t he f ram e t yp e. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich D a t a— Cont ains upp er - lay er dat a in t h e for m of an encapsulat ed PLP p ack et . pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr oduFCS ct iv it an d im prerr ovor e eff iciency, help ingsutres he rteader m ake mor e in t elligent , cost eff icient —y Handles checkin g an d en h e int egr it y of t he t ran sm it t ed dat-a. decisions for t h eir net w ork s.

X.121 Address Format X. 121 ad dr esses are used by t he X. 25 PLP in call set up m ode t o est ab lish SVCs. Figur e 17 - 7 illust rat es t he f orm at of an X. 1 21 addr ess. •

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Figu r e 1 7 -7 . Th e X.1 2 1 Addr e ss I n clu de s an I DN Fie ld

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . ComX. plet e wAddr it h new an d uinclud pdat ed erer s nat on ional secur it y , astNu or age, ical ,net w or kcon in g,sist scalabilit The 1 21 ess field es chapt t he I nt Dat m beropt ( I DN) w hich s of t w oy, and speed, t h isa book is ka Icom e ion an dCode u p- t od at eC)r ef er ence t o tion he al t opTer icsminal t hat are ial t o. all fields: t he Dat Net wor dentplet if icat ( DNI and t he Nat Numessen ber (tNTN) net w or kin g p rof essionals, r egar dless of ex pert ise. DNI C is an opt ional f ield t h at ident if ies t he exact PSN in w hich t h e dest inat ion DTE device is Reader w ill obt ainisasom g reat er es un om deritstt an of LAN n etPSN. w or k ing, ar tC icuhas lar ly locat ed s. This f ield et im ed ding in calls w it hand in t hWAN e same The p DNI t wtoh e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on subf ield s: Coun t r y and PSN. The Count ry su bfield sp ecifies t he cou nt r y in wh ich t h e dest in at ion a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions PSN is locat ed. Th e PSN f ield specif ies t h e exact PSN in wh ich t h e dest in at ion DTE device is tlocat o ened su .re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst s, ident pr ovid in g t a oract e r ealist pict ld naetpwack or keting virined. onm ent s in w hich The em NTN ifies h emex D TE dicev iceurine tof het he PSNrealf or wwor hich is en d est This field pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease v aries in len gt h. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary X. 25 is an I TU- T st an dar d pr ot ocol t hat defin es h ow conn ect ions b et ween user devices and net w or k dev ices ar e est ab lish ed and m aint ained, and t hat oper at es ef fect ively r eg ard less of t h e t y pe of sy st em s conn ect ed t o t h e net w ork . X. 2 5 d ev ices in clud e DTEs, DCEs, an d PSNs. X. 25 •connect ions cont Tableain of Content s bot h SVCs and PVCs w it hin t he phy sical cir cuit . X. 25 uses t he follow in g t hr ee •pr ot ocols, w hich I ndexm ap t o t he bot t om t hr ee lay er s of t h e OSI r efer en ce m od el: I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

PLP, w hich m aps t o t h e net w ork lay er

PubLAPB, lish er: Cisco Press wh ich m aps

t o t he dat a lin k layer

Pub Dat e: Sep tem ber 1 1, 2 003

X.I SBN: 21b is, A/-1TI19A1- 58EI 705 -22 32, EI A/ TI A- 449 , EI A- 53 0, an d G.7 03, w hich m ap t o t he ph ysical layer Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

I n wh at k ind of net w or ks does X. 25 generally op er at e?

2:

I ndexe t he t hr ee general cat egor ies int o w hich X. 25 dev ices f all. Nam

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Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

: What ar e By Cisco 3 Systems, Inc. 4:

t he t hr ee main f unct ions of t h e PAD?

Nam e t he X. 2 5 p rot ocol su it e and t he lay ers in t h e OSI r efer en ce mod el t o w hich t hey m ap.

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 18. Virtual Private Networks (VPNs) • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Under st and t he d ef init ion of VPN and t he cat egor izat ion of VPNs based on t h e und er ly in g t echnologies, applicat ions, and p rov ided ser v ices.

By Cisco Systems, Inc.

PubUnder lish er: st Cisco andPress t he

b asics of I PSec pr ot ocols and t he I KE pr ot ocol.

Pub Dat e: Sep tem ber 1 1, 2 003

Under and he19b-2asics of L2 TP. I SBN: st 1- 58 705t-1 Pages: 11 28

Under st and t he b asics of MPLS- based VPN. As m or e comp anies hav e st ar t ed t o rely on t he I n t er n et for t heir com m un icat ion s, t he m ar ket of v irt u al pr iv at e net w or ks ( VPNs) has g row n signif icant ly in r ecent y ear s. VPN t echn olog ies cont inu e t o ev olve as new st andar d s, pr oduct s, and serv ices em erg e. This has cau sed comp anies tThe hat uwpdat ant ed t o dedit ep loy ion VPNs of t hesome b est - con selling fusion all-over in- one w hnet at is w ork a VPN, ing r ef w hat erence t yp es p rov of ides ser vices covercer age t ain of tessent y pes of ialVPNs an d cu prtov t ingide,edg and e tw ech hatnologies. is t he r igh t t y pe of VPN for t hem . Tr yin g t o clear ly defin e and cat eg or ize VPN is an ongoin g t ask . This ch apt er is not an at t emp t t o Conacise ov- cu er vt iew ofion t echn olog iesI nst essen t ial n etint wor k ing pr ofession alserat all lev pr ov ide clear d efsinit of VPNs. ead, it 'st oan r odu ct ion t o and ov v iew of els, diff erf rom ent nov ice t o ex pert . t y pes of VPN t echnolog ies. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

VPN Definition AVPN is a logic n et w or k t h at oper at es on t op of a shar ed p hy sical inf r ast ru ct u r e. Com par ed t o t he t rad it ional w ay s of using dedicat ed leased circu it s t o int er connect of fices at d iffer ent geogr aph ic locat ion s t o b uild a pr iv at e net w or k, t he cur r en t VPN is vir t ual in t he sen se t hat t he •net w or k facilit Table Content s ies uofsed t o build it ( such as t he I n t er n et ) ar e shar ed by ot her comp anies as w ell. •VPNs pr ov ideI ndex pr iv acy , j ust as leg acy p r iv at e n et w or k s do. The circuit s are dedicat ed t o t he Icust nt e rn et w Te can chnologie a ndbook th Edit ion om erors,k ing w ho h aves tHheir ow n, Four I P addr essing , r out ing sch em es, and secu rit y p olicies. By Cisco Systems, Inc.

The " pr iv at e" in VPN t er m inology can also be in t er pr et ed f r om a secur it y per sp ect iv e. What secur e ser vices a VPN can pr ov ide has becom e a m ore com m on quest ion ask ed b y com p anies Pub lish er: Cisco Press w hen t hey consider imp lem ent ing VPNs. Pub Dat e: Sep tem ber 1 1, 2 003 1- 58 705 -1t 19 Let ' s firI SBN: st consider h e-2ex am ple of VPNs u sing d ed icat ed cir cuit s, such as Fr am e Relay . They ar e som etPages: im es 11 called 28 t r ust ed VPNs, b ecau se cust om er s t r ust t h at t h e net w or k facilit ies op er at ed by t he ser vice pr ov ider s w ill not be com pr omised. So no r eal secu re ser vices ar e pr ov id ed b y t his t y pe of VPN.

As m or e comp anies use t he I n t er n et as t he backb one of t h eir VPNs, our pr esu mp t ion is n o long er t r ue. Fur t her m ore, t h e dat a t r aver sin g t he I nt er net is m or e subj ect t o at t acks, such as loss of The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of pr iv acy , loss of int egr it y , and ident it y sp oofing. So it becom es cr it ical f or VPNs t o pr ov id e secur e essent ial an d cu t t ing- edg e t ech nologies. ser v ices, such as confid en t ialit y , int eg rit y , an d au t hent icat ion, t o pr ot ect t h e dat a fr om possible at t ack s. To pr ov ide such secur e serv ices, t u nneling t ech nologies and cry pt ogr aphic algor it hm s ar e oft en cise usedovt oersecu com m unicat ions acr oss n twor er net . This t y pe of als VPNatisallcalled a secur Con v iewre s of t echn olog ies essen t ial tthe o nI et k ing pr ofession lev els, f rom e VPN. nov ice t o ex pert . BasedNew on tchapt his d ef ion, w ecov canerag pu te cur ent nologies intPo and t w o EAP cat egor ies: erinit s include of rim porVPN t antt ech t opics like VoI Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Tru st e d V PN t e ch nolog ie s— The m ost p rom isin g t echn ologies are t he MPLS- based t echnologies: MPLSSy VPNs u sing andleader MPLS-inbased L2king VPNs. Aut h ored by Cisco st ems, w orBGP ldw ide net w or f or t he I n t er n et . cure VgP N t echn ologiHand es— book The m ost pt opular t echnolog iesprar e I PSec,refer L2TP or L2 TP I n t ernSe et w or k in Tech nologies , Four h Ed it ion , is a com ehensive ence t hat pr ot ect ed b y I PSec, and PPTP. I PSec has becom e t h e de f act o st and ard f or secur e VPN in enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing r ecent year s. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

VPN Applications VPN t echn olog ies ar e ap plied in t he f ollowin g scen ar ios:

• •

I nt r an et Table s—ofWit Content h VPN s t ech nologies, com p anies can use t h e I nt er net as a back bone t o link t heir g eog rap hically d isp er sed sit es via VPNs. I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ex t ra ne t s— VPN t ech nologies can also be used t o cr eat e in st ant , on - dem and lin ks bet w een com panies and t heir b usin ess p art ners.

By Cisco Systems, Inc.

PubRe lishm er:ot Cisco Press e- access—

VPNs let r em ot e u ser s access cor por at e net w or ks t hr ough VPNs af t er ser vice pr ov ider ( I SP) . This is m u ch m or e cost - ef fect iv e t h an t he t rad it ional w -2 ay of com panies m aint ainin g a larg e m odem ban k t hem selv es. I SBN: 1- 58 705 -1 19

Pub loggin Dat e: g Sep on temt o bera1local 1, 2 003I nt er net

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IPSec An int ern at ional g rou p org anized u nder t h e I nt ern et En gineering Task For ce ( I ETF) has dev elop ed t he I P secur it y ( I PSec) pr ot ocol suit e t o secur e I P t raf fic at t he net w ork lay er. I PSec is a set of p r ot ocols d ef ined in sever al RFCs. I t uses cr y pt ogr ap hic t ech nologies t o pr ovide key •secur it y serv Table of Content s m on secur it y t hr eat s on t he I n t er net . Th ese secu r it y ser v ices ar e as ices against com •follow s: I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Aut h en t icat ion gu ar ant ees t hat t he VPN device comm u nicat es w it h t h e int ended en t it y .

PubCon lish er: Ciscoialit Press fident y

ensur es t he d at a's pr ivacy by en cr y pt ing t h e dat a.

Pub Dat e: Sep tem ber 1 1, 2 003

I nt egr it t ees t hat t he dat a's cont ent has not b een m odified dur ing t r ansm ission. I SBN: 1-y58gu 705aran -1 19 -2 Pages: 11 28

The f ollow in g ar e som e of t he key cr yp t ogr aphic t echn ologies used by t he I PSec pr ot ocol suit e t o achieve t hese secur it y ser v ices: Con t en t encr yp t ion alg orit h m s ar e usually sym m et rical encr yp t ion alg orit h m s t hat ar e used The utpdat o ened cr yedit pt dat iona.ofTht he e mb ost est -com selling monallly inused onealgor net witork hm ing s ar reefDerence ES, 3DpES, rov an ides d AES. cover age of essent ial an d cu t t ing- edg e t ech nologies. The h ar d- t o- inv ert and st r ong collision- f ree char act er s of cer t ain h ash algor it hm s ar e u sed t o generat e a dig it al fin gerp rin t t h at pr ov ides aut h en t icat ion and int eg rit y f or a sp ecific Con cise ovIer v iewuses s of taechn ologhash ies essen ial t o ngener et woratkeing ofession als at allmlev els, f rom m essage. PSec k eyed fun ct tion a kpr eyed hashb ased essage nov ice t o ex pert . aut h en icat ion code ( HMAC) t o pr ov ide dat a or igin aut hent icat ion and dat a int egr it y. The hash algor it hm s used by I PSec are MD5 and SHA- 1. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP The D iff ie- Hellm an ( DH) key ex ch ange pr ot ocol allow s t w o VPN d ev ices t o secu rely Cov erag cut m t ing t echn opt ical en et wor kel ingw itand st or age gener at ee aofcom on edge sh ared secrologies et ov er lik ane in secur chann hout any p rior shar ed secr et s. Wit h an au t hent icat ed D H exchan ge, t he t w o VPN p eer s can est ablish a secu re Aut h ored by Cisco Sys st ems, w or ldw ide leader in netdu w ring or king t he iat I n tion er nof et .t he I PSec chann el t hat pr ot ect t he m essages b et w een t hem t h ef or negot secur it y associat ion . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables or kin g pI rnfr ofessionals un derst imotplem en st t cont em poran ardy ser int er net w ork ing Thenet Puwblic Key ast r uct ur et o( PKI ) conand sist san ofdpr ocols, andar ds, vices t hat t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w supp ort t he applicat ion of p ublic k ey algor it hm s. Com par ed t o cont ent en cr y pt ion ork ing indu stalgor ry . Lear t o incor pororit at ehint net w or m kinmet g t rechn olog ies a LAN/ WAN it hmns,how pu blic k ey alg mserare asy ic. Each en tin it yt ogener at es a penv air ir ofonm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit m at hem at ically associat ed k ey s. The p ublic k ey is pub lished t o t he pu blic dom ain, and y, t he and speed, t h is book plet p- at t o-e.d at e en r ef er o t key he t,op t hat areat essen corr espond in g prisivaatcom e k ey isek an ep td puriv Giv t hence e pubtlic it ics is m at h em icallyt ial t o all net w or g p roftessionals, ex. pert infkin easible o find ou t rt egar h e prdless ivat e of key Thisise. char act erist ic m ak es p ublic k ey algor it hm s usefu l for bot h encry pt ion an d d ig it al cer t if icat ion . RSA is t he m ost f am ous exam p le of a pu blic Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e k ey alg orit h m . Via a t ru st ed cer t if icat e aut hor it y ( CA) , each VPN ent it y in a PKI syst em can har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on bind it s p ublic k ey and it s ident it y , such as I P ad dr ess an d f ully qu alif ied dom ain nam e, a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions using a cer t ificat e issu ed by a CA. W hen u sed in an I PSec VPN, PKI p rov ides secu rit y t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ser v ices, such as aut h en t icat ion and non r ep udiat ion. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst s, prVPN ovidar inchit g a ect m or ealist ic pict ur eing of com t he realw or The em I PSec uree rhas t he f ollow ponent s:ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions forh ten h eir net s. ( AH) is added t o an I P packet t o pr ov ide d at a or igin An aut t icat ionw ork header aut h en t icat ion an d d at a int eg rit y check in g. An en cap sulat ing secur it y pay load ( ESP) for I P pr ovid es encr y pt ion, d at a or igin aut h en t icat ion , and dat a int egr it y checking .

I nt er net Secur it y Associat ion and Key Managem en t Pr ot ocol ( I SAKMP) and I nt er net Key Ex chang e ( I KE) allow VPN dev ices t o secur ely negot iat e and m anag e I PSec secur it y associat ions ( SAs) and gener at e, ex chang e, and m anage t he k ey s t h at ar e u sed by t h e cry pt ogr aphic alg orit h ms em ploy ed b y I PSec. I n t he f ollow ing sect ion s, t he discussion is d iv ided int o t he f ollow ing t opics: • •

of Content Aut h en tTable icat ion headers I ndex

I nt e rn En et wcap or k ing Teing chnologie , Four th Edit ion su lat Securs itHya ndbook Pay load By Cisco Systems, Inc.

I PSec t ran spor t m ode an d t unn el mod e

PubSecu lish er:ritCisco Press y Associat ion Pub Dat e: Sep tem ber 1 1, 2 003

I nt er net Key Ex e pr ot ocol I SBN: 1- 58 705 -1 19chang -2 Pages: 11 28

Authentication Header (AH) Defin ed in RFC 2 402 , AH is a header t h at I PSec adds t o an I P d at agr am . I t r esides b et w een t he u pdat of t he b est - selling net w ork r ef erence p ed rovHMAC ides cover age ed of IThe P h ead er ed an dedit t heion Layer 4 pr ot ocol h eadaller .inThone e header is ing basically a k ey calculat essent ial t ingedgand e t ech based on an t h ed Icu P tpay load t henologies. I P header except for t he m ut ab le field s t hat chang e dur ing t h e t r ansm ission, such as t h e TTL field . Verif icat ion of t h e AH header b y t he r ecip ien t pr ov ides dat a or igin aut hent icat ion and dat a int egr it y. Figur e 18 - 1 sh ows t he f orm at of t he AH. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Figu r e 1 8 -1 . Aut he nt i ca t i on H ea de r

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . The f ield s ar e as follow s: Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper and gu f or -opt em per foras m ance w illTCP. incr ease Next Head er at ( 1e.byTools t e) indicat esidt elines he higher levim el izing AH p rsyst ot ocol, su ch UDP or pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for tLen h eirgtnet Pay load h (w1 ork by s. t e) specif ies t he lengt h of t h e AH. Reser v ed ( 2 by t es) is r eser v ed f or fu t ur e use. I t is cur r ent ly set t o 0. Secu rit y Param et ers I n dex ( SPI ) ( 4 by t es) specif ies t he set of secu rit y p ar amet er s kn ow n as t h e secur it y associat ion for t he I PSec connect ion.

Sequence Num b er ( 4 b yt es) t rack s t he or d er of I PSec pack et s for an t i- r ep lay pur poses. Aut h en t icat ion Dat a ( v ar iab le size) con t ains t he I P pack et ' s int egr it y check v alu e ( I CV) . AH p ack et s ar e I P p ack et s w it h pr ot ocol t y pe 51 .

Encapsulating Security Payload (ESP) • Table of Content s •

I ndex

IESP nt e rnisetdefined w or k ing Te s H.a ndbook , Four inchnologie RFC 2 406 Com par ed ttho Edit AH,ion ESP pr ov ides dat a con fident ialit y b y en cry pt in g t h e IByP Cisco p ack Systems, et s. The Inc. au t hent icat ion p r ovided by ESP does n ot cov er t he I P h ead er , as does AH.

Figur e 18 - 2 illust r at es t he for m at of t h e ESP. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 1 8 -2 . En cap su la t i ng Se cu r it y Pa yl oad

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu fst ry .sLear t o s: incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . The ield ar e nashow follow Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Secu Param et ers rI negar dexdless ( SPI )of( 4exby t es) specif ies t he set of secu rit y p ar amet er s kn ow n net w or kin gritpyrof essionals, pert ise. as t h e secur it y associat ion for t he I PSec connect ion. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Num b and er ( 4ser b yt es) tinv rack s ed t he. Fu or ndam d er ofent I PSec pack et s forinfan i- r ep layispur poses. har dwSequence ar e, pr ot ocols, v ices olv al t ech nology ortmat ion pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions The in g cept f ield scomp ar e en y pt ed: and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . t o enf ollow su re con r ehcren sion Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Pay load D at a cont ains t he act ual dat a car r ied in t he I P packet s. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr oduPadd ct iv itin y gan( 0d tim iciency, heh rof eader t elligent - effain icient o pr 25ov 5 e byeff t es) allow shelp t h eing len tgt plainmt ake ext tmor o b ee ainm u lt ip le ,ofcost a cert nu mb er decisions for t h eir net w ork s. of by t es t o sat isfy t he r equir ement of some en cr y pt ion algor it hm s t hat oper at e on blocks of dat a or t h e r eq uirem ent of d at a align m en t . Pad Lengt h ( 1 b yt e) sp ecifies t h e len gt h of t he p adding . Next Head er ( 1 by t e) defin es t he pr ot ocol t y pe of t he dat a car ried in t h e Pay load Dat a f ield.

Aut h en t icat ion Dat a ( v ar iab le len gt h) cont ains t h e int egr it y check valu e ( I CV) . Unlike t he AH, t h e I P header of t h e ESP packet is not cov ered by int eg rit y ch eck in g.

IPSec Transport Mode and Tunnel Mode Bot h AH an d ESP hav e t w o en cap sulat ion m od es—t r anspor t mod e and t u nnel m ode ( see Figur e • Table of Content s 18 - 3) . •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 1 8 -3 . I PSe c Tr a nspor t M ode a nd Tun ne l M ode Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. I n t ran sp or t m ode, t h e I P header of t h e or ig inal I P packet is used as t h e I P header of t h e I PSec pack et ,sand he ain I PSec is der in ser t edding b et wofeen I PWAN h ead n eretand load Reader w ill tobt a gheader reat er un st an LANt he and w or kt he ing,I Pp pay ar t icu lar.lyI nt ht unn e el m ode, I PSec enocols, cap su and lat esser t he cominv plet e ed or ig inal I P pent acket an dnology a newinf I Porhmat ead ion er isisadded as t on he har dw ar e, pr ot v ices olv . Fu ndam al t, ech pr ov ided IaPbhr oad ead er of tehe PSec . s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions r ang of Iint egr packet al sy st em t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Tun nel meode p rovext ides r aff ict oflow by hiding t healso origtin dr ess Cov erag is also endlim editned ot tonly newcon n etfident wor kialit ing yconcep t s, but o al oldI P erad , legacy inf orm syst emat s,ion. pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions forAssociation t h eir net w ork s. (SA) Security From t he p reced ing sect ion, y ou can see t hat an I PSec ent it y can h ave d iffer ent ch oices of encry pt ion algor it hm s, h ash algor it hm s, I PSec mod es, an d so on. Th ese p aram et ers and ot her inf orm at ion r eq uir ed t o est ab lish an I PSec conn ect ion are main t ained b y t he I PSec SAs. I n gener al, an SA is a relat ion bet w een t w o ident it ies t h at ap plies secur it y ser v ices t o t he t r af fic

t hey car r y. For an I PSec connect ion, t w o unidir ect ion al SAs ar e m aint ained on each I PSec peer—one f or inbou nd t r aff ic and one f or out b ound t r aff ic. An I PSec SA is uniq uely id en t ified by t hr ee par am et er s: u sag e of AH or ESP, SPI , and t h e dest inat ion I P add ress.

Internet Key (IKE) Protocol • Table Exchange of Content s •

I ndex

IAlt nt ehou rn etgh w orI kPSec ing Tesup chnologie a ndbook , Four thr at Edit ionof it s secur it y associat ions, it b ecom es obv ious por t s smH anual configu ion tBy hat y ou need an aut om at ic m ech anism t o ach iev e scalabilit y an d f lex ibilit y . This m ech anism Cisco Systems, Inc. should allow VPN d ev ices t o negot iat e and m anage I PSec SAs and g en er at e an d d ist r ibu t e k ey s w it hout hu m an int er v en t ion. I KE, defined in RFC 24 09, is t he p rot ocol design ed f or t his p ur pose. Pub lish er: Cisco Press

e:br Sep 1 1, 2 t003 I KEPub is aDat hy idtem prber ot ocol hat int egr at es I SAKMP an d Oakley Key Ex chang e. I SAKMP, defined in I SBN: 158 705 -1 19 RFC 240 8, is an open -2fr am ew ork t hat d ef ines t he pr ocedu re and packet for m at t o est ablish , Pages: 28 y, and delet e secur it y associat ions. I n conju nct ion w it h I PSec Dom ain of negot iat e, m11odif I nt er pr et at ion , def in ed in RFC 240 7, I KE defines a det ailed im plem ent at ion t o man age I PSec secur it y associat ion s und er t he I SAKMP fr am ew or k .

I KE is a t w o- ph ase pr ot ocol. I n an I KE phase I ex ch ange, t h e t w o VPN en t it ies at t em p t t o est ablish an aut h en t icat ed, secur e chann el t hat is used t o pr ot ect subsequ en t com mu nicat ions The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of bet w een t h e t w o ent it ies. This is accomp lish ed in t hr ee st ep s: essent ial an d cu t t ing- edg e t ech nologies. St e p 1 . The t wo VPN ent it ies negot iat e t he cr yp t ogr aph ic alg or it hm s t hat w ill be u sed in t he cise phase I vex ch sange t o est ablish t h e phase associat ion, also k now n as I SAKM Con ov er iew of t echn olog ies essen t ial t oI nsecur et woritky ing pr ofession als at all lev els, f romP SA or I KE SA. nov ice t o ex pert . St e pchapt 2 . The wo VPN cov enterag it ies ego hr oug a DH ex chang e. This New er st include of t im por thant t opics like VoI P andexchan EAP ge allow s t hem t o secur ely gener at e a com m on secret over t h e insecur e chan nel w it hou t any pr ior shar ed secrerag et . Toget her w itedge h ot her inf or m at ionlikin t heical negot ion, t h is comm Cov e of cut t ing t echn ologies e opt n etiat wor k ing and st oron agesecr et is used t o gener at e sev er al k ey s, one of w h ich is used t o pr ot ect sub sequ en t com m unicat ions Aut Sy sten ems, w or ldw ide leader in net w or king f or t he I n t er n et . bethwored een by t h eCisco t w o VPN t it ies. I n t ern St et w g Tech nologies book , Four t h Ed it ionby , issendin a comgpritehensive ence hat e or p k3 in . Each VPN ent it yHand au t hent icat es t he ot her s id en t it y,refer su ch as ItP enables net w or kin g p r ofessionals d im en tside conttem ar. yThint ingI KE add ress, FQDN, and a key edt oh un ashderst pay and load,anfor t h plem e ot her o v por er ify erer e net ar ewtork h ree t echnologies. Mast er m t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing aut h en t icat ion et hods: indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t-h Aut is book a ion comwplet d u pt o- dk at ereshar ence ed t o tkey he tis opaics hat hent is icat it h ea an pr esh ared eye. rAefpr shtar ed are secressen et t ial t o all net w or kin g pprrof essionals, einst alled onr egar eachdless VPN of entex it ypert viaise. an ou t - of- b and m echan ism . Th is pr eshar ed key is one of t he inp ut p ar amet er s for t he k ey ed hash p ayload . So w it hou t m at chin g t h e Reader s w ill pr obt ain der st ver an ding WAN n et w or ar t su icucceed. lar ly t h e esh ar a edg kreat ey ,er t h un e hash ificatof ionLAN in I and KE aut hent icat ionk ing, w ill pnot har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang- eAut of hent int egr al ion sy stwem clud ingEach det ailed rev iewesquest ions icat it hspand ublicserv k eyices, en crin y pt ion. I PSecdescr p eeript f irion st s, generat a t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . pseudo- r an dom nu m ber called a non ce. Th e non ce is t hen encr y pt ed usin g t he ot h er Cov erag e is par alsot yext endlic ed kney. ot only t ohnew n et k ing t s,ptbut t o old er , legacy 's pub The ot er par t y'wor s ab ilit y concep t o decry t healso nonce using it s p riv at e k ey syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm s in wpeer hichs and r econ st r u ct t he h ash p ayload aut h en t icat es t h e I KE ex chang e. Th eent I PSec pr of essionalsmoper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease ight need t o use an out - of - ban d m echanism t o ex chang e t heir pu blic k ey s in pr odu ct iv it y adv an dance. im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. - Aut hent icat ion w it h d igit al signat u r es. Th e hash pay load used for I KE aut h en t icat ion is signed by t he I PSec en t it y' s pr iv at e k ey . D ur in g I KE aut hent icat ion , each p art y perf or ms t he hash v er ificat ion aft er d ecr yp t ing t he h ash p ayload using t he peer ' s pub lic key , w hich is obt ained fr om t h e peer ' s digit al cer t ificat e. The u se of digit al cer t ificat es pr ov ides nonr epud iat ion.

The I KE ph ase I ex chang e can b e accom p lished in eit her m ain mod e or ag gr essive m od e. Main m ode u ses a min im u m of six packet s, and ag gr essive m od es u ses a m in imu m of t hr ee pack et s. Main m ode is m or e secur e t h an ag gr essiv e mod e bu t less ef ficien t . I n I KE ph ase I I ex chang e, also kn ow n as qu ick m ode, t h e t w o VPN en t it ies negot iat e and est ablish I PSec SAs. This exchan ge is pr ot ect ed b y t he p hase I SA, an d all t he ex ch anges ar e aut h en t icat ed . The d at a encr yp t ion k ey s used b y I PSec ar e also d er iv ed in t his ph ase. An ex t ra DH ex chang eTable can of b eContent per forsm ed t o generat e new shar ed secret s t h at ar e u sed t o d er iv e I PSec • dat a encry pt ion k eys. Th e new er k ey gener at ed b y t his D H exchan ge is ind ep en dent fr om t h e • I ndex older k ey s g en er at ed in p hase I . This ex t ra secur it y is called Per fect For war d Secr ecy ( PFS) . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

By Inc. ex chang e, t w o un idirect ional I PSec SAs ar e est ablish ed . I PSec uses t hem t o AftCisco er a Systems, qu ick m ode pr ot ect t h e dat a t r aff ic. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Layer 2 Tunneling Protocol (L2TP) The I ETF w as faced w it h com pet ing pr oposals fr om Micr osoft and Cisco Sy st em s f or a p rot ocol specif icat ion t h at w ould secur e t h e t r ansm ission of I P dat ag ram s t h rou gh un con t rolled and un t r ust ed net w or k dom ains. Micr osoft ' s pr oposal w as an at t em pt t o st an dar dize t h e Point - t o•Point Tunn eling Table s ProfotContent ocol ( PPTP) , wh ich it had ch am pioned. Cisco also h ad a pr ot ocol d esigned t o •per for m a sim I ndex ilar f unct ion. Th e I ETF com bined t he b est elem en t s of each pr oposal an d sp ecified It he nt e rn et w orstk an ingdar Te chnologie open d L2TP. s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

PPP est ablishes a Layer 2 poin t - t o- poin t link on w hich PPP connect ions encapsulat e and t r anspor t m ult ipr ot ocol pack et s. A net w or k access ser v er ( NAS) t er m inat es t he Layer 2 p oin t - t o- poin t link Pub lish er: Cisco Press est ablish ed by user s v ia v ar iou s t echnologies, such as dialup POTS, I SDN, an d AD SL. Th e NAS is Dat e: Sep tem ber 1 1, 2 003 t he Pub t er m inat ion point of bot h Layer 2 point - t o- point link s and PPP sessions. I SBN: 1- 58 705 -1 19 -2

Wit h L2 Pages: TP, t11 he 28 t er m inat ion point s of t he Lay er 2 cir cuit and PPP session can b e separ at ed by dif fer en t dev ices int er connect ed b y I P net w or k s. I n ot h er w or ds, u ser s can dial in t o a local NAS, and t h e PPP session is ex t end ed by an L2TP conn ect ion across a shar ed inf r ast r uct u re, such as t he I n t er n et or a Fr am e Relay net w or k, t o a hom e gat ew ay t h at p rocesses and m anag es t he PPP session. As f ar as t h e users are con cer ned, t h ey get t h e same fun ct ion alit y but pay on ly local ph chared ges. Theone u pdat edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. L2 TP sim ulat es a poin t - t o- poin t connect ion by encapsulat ing PPP dat agr am s f or t r anspor t at ion t hr ou gh rou t ed n et w or k s or int er net w or ks. Wh en t h e PPP d at agr am s ar riv e at t heir int ended dest inat encapsulat isolog r emies ov ed , and t hteo dat ram s arpreofession r est oredals t oat t hall eir lev origin Conion, ciset he ov er v iew s of tion echn essen t ial n etag wor k ing els, alf rom for m at . Th us, a point t op oint com m unicat ions session can be supp ort ed t hr ou gh dispar at e nov ice t o ex pert . net w or ks. Th is t ech nique is called t unn eling . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP The f ollow in gs ar e t h e key com ponent s in an L2TP conn ect ion: Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age N e thwored ork by Acce ss Se er ( NwAor S)ldw — ide A dev ice p rin ovides onking - deman local n et wor Aut Cisco Sy rv st ems, leader net w or f or tdhe I n t er n et . k access t o users. I t is t he t er m inat ion point of Lay er 2 point - t o- p oint lin ks est ablished b y end user s g PSTN or I SDN I n t ernt yetpically w or k inusin g Tech nologies Handlines. book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing L2 TP Acce sserCon ntm r at A nod e usually s as t h used e init iat of t'hsenet L2TP t un nel t echnologies. Mast t hecet er s, or con( LAC) cep t s,—t echn ologies, an dact devices in or t oday w ork ing t o t he L2TP Net w or k Serv er ( LNS) . LAC for w ar ds pack et s bet w een end user s an d LNS. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, L2 TP N or k is Searvcom e r (plet LN S) —dAunod e dact s as t h ence e t er m of tare he PPP sessions and speed, t het is wbook e an p- t oat e r ef er t oinat t heion t oppoint ics t hat essen t ial t o all t hat t r av el t hr ough t h e L2 TP t un nel init iat ed by LAC. net w or kin g p rof essionals, r egar dless of ex pert ise. LAC ands w LNS only ef g ine t he ic fustnct L2and TP connect Thk ing, eir p phy locat Reader ill obt aind a reat er log un der anions ding of of an LAN WAN n ion. et w or arsical t icu lar ly tions he depend on dif ferent im plement at ion t op ologies and requ irem ent s, as discussed in t he f ollow har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ideding on sect ions. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Implementation Topologies pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr ct iv itbe y an im pr oved e eff t he r eader m ake mor e in t elligent , cost - eff icient L2odu TP can im dplement in iciency, t w o disthelp inct ing t opologies: decisions for t h eir net w ork s. Com pu lsor y t u nneling or client - t ran spar en t t u nneling Volunt ary t unn eling or clien t - aw ar e t unn eling

The d ist in ct ion bet w een t h ese t w o t opologies is w het her t h e client m ach ine t h at is u sing L2TP t o access a rem ot e net w or k is aw ar e t hat it s connect ion is bein g t unn eled. LAC' s phy sical locat ion v aries in t hese t w o t op ologies.

Compulsory Tunneling •Com pu lsor y tTable of Content u nneling feat sur es LACs dist r ib ut ed geogr aphically close t o t he r em ot e users. Su ch •geogr aph ic dispersion I ndex is int ended t o r edu ce t he long - dist ance t eleph one char ges t h at w ould Iot nther e rn w et ise w or b k ing Te chnologie H a ndbook , Four th Edit ion e incur r ed by s rem ot e user s dialing int o a cen t r ally locat ed LAC. By Cisco Systems, Inc.

Rem ot e user s need n ot supp or t L2TP d ir ect ly, as sh ow n in Figur e 18 - 4. Th ey m er ely est ablish a point - t o- point comm u nicat ion session w it h t h e NAS, w hich is also t he LAC, u sing PPP. Pub lish er: Cisco Press Ost ensibly, t he u ser encapsulat es I P d at agr am s in PPP f ram es. The LAC ex ch anges PPP m essages Datr e: Sep tem ber 1 1, 2 003 w it hPub t he emot e user and est ab lishes an L2 TP t u nnel w it h t he LNS t h rou gh w hich t he r emot e I SBN: 158 705 -1 19 -2 user' s PPP messages ar e passed. The LAC can also aut h en t icat e t he end users and use t he user s' inf ormPages: at ion,11su 28 ch as dom ain n ame, t o dir ect t he end u ser s t o t he m at ching LNS.

Figu r e 1 8 -4 . Com pul sor y L2 TP Tun n el s The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The LNS is t h e r em ot e u ser 's gat ew ay t o h is hom e net w or k. I t is t h e t er m inu s of t he t u nnel; it I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat st r ip s off all L2TP en cap su lat ion an d ser ves u p n et w or k access f or t he rem ot e user . enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing tAs echnologies. t erario, m s, tcon t echn ologies, net w ork ing can be seenMast in ter hist he scen he cep endt s, users don' t h avean and ydevices choice, used and tin het oday L2TP' st unnel indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . est ablish ed by L2TP- sup por t ed NAS is t r anspar en t t o t he end u ser s. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

Voluntary Tunneling

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e harshow As dw ar ne, inprFigur ot ocols, e 18and - 5, tser h evLAC ices fu inv nct olv ion ed .resides Fu ndam onent t he al clien t ech nology t m achine, inf orand mat tion h e is end pr ov user ided is on raespon b r oadsib r ang le for e of in it int iat egr in galt sy hestL2 em TP s conn and serv ect ion. ices,The in clud client ingfirdet st ailed g et s Idescr P connect ipt ionivit s, yrev b yiew eit quest her ions est t o en ablish su reincon g acept PPP comp con nect r ehion en sion t o a and NASr at et en t he t ion, local and I SP ador ditconnect ional r esou ing rt ces o a local f or fu LAN rt hersegm st udy ent . . Then Cov erag it init e isiatalso es t hext e L2TP end edconnect n ot only iont ot onew t h e nLNS, et worwkhich ing concep t erm inat t s,esbut t h ealso L2 TP t o told un nel er , legacy and t h e ext systend emed s, pr PPP ovid session in g a m . or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figu r e 1 8 -5 . Vol un t a r y L2 TP Tu nn e ls

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of L2TP by eIPSec essent ialProtected an d cu t t ing- edg t ech nologies. As usefu l as L2TP is, it is imp ort ant t o r ecog nize t hat it is n ot a panacea. I t enab les flexibilit y in Con iew s of bu t echn olog ies o n etdwor k ingofprsecu ofession at all deliver ingcise r emov oter e vaccess, t it does notessen aff ortdiala thigh eg ree rit y f als or dat a inlev t r els, ansitf rom . This nov ice t o ex pert . is du e in lar ge par t t o PPP's relat ively insecu r e nat ur e. I n fair ness, PPP w as designed ex plicit ly for point - t o- point com m un icat ions, so secur ing t he conn ect ion should not hav e been a high pr ior itNew y. chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Covion erag of cutof t ing lik ef act opt tical et wor kting An addit al ecause conedge cer n tstechn em sologies f rom t he h at nL2TP's unn and els arsteornage ot cr yp t ogr aph ic. Their dat a pay loads ar e t r ansm it t ed in t h e clear , w r apped only by L2TP and PPP f r amin g. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . How ev er , add it ion al secur it y m ay b e aff ord ed b y imp lem ent ing t h e I PSec p rot ocols in conj unct L2TP. As d escr ib edbook in t he " I PSec" e I PSec p r ot ocols sup por t t st r ong I n t ern et wion or kwinitgh Tech nologies Hand , Four t h Ed sect it ionion, , is at hcom pr ehensive refer ence hat aut h en t icat ion t echnolog ies as w ell as encr y pt ion. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

MPLS VPNs The I PSec and L2TP VPNs d escr ib ed in t he pr ev ious sect ion s ar e oft en pr ov isioned and oper at ed by ent er pr ise cust om er s. They ar e of t en called CPE- based VPNs. I n recen t y ear s, ser vice pr ov iders hav e been t r y ing t o lev er age t heir ex ist ing I P inf rast r uct ur e t o pr ov id e new serv ices, •such as pr ov id Table Content er - pofrov ision sed VPNs ( PPVPNs) , t o ent erp r ise cust om ers. A few m ult ip rot ocol lab el •sw it ch in g- ( MPLS) I ndex based VPNs ar e of fer ed b y ser v ice p rov ider s: I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

BGP/ MPLS VPNs

PubMPLSlish er: Cisco Press based Lay er

2 VPNs

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 VPN BGP/MPLS

The BGP/ MPLS VPN, descr ibed in I ETF dr aft - iet f - ppv pn - rf c254 7bis, is a Lay er 3 VPN. I n t his case, ent er pr ise cust om ers com p let ely out sour ce t heir VPN t o serv ice pr ovid er s w ho m anage t he I P VPN as well as t he cust om er ' s r out ing acr oss t he VPN. Ser vice pr ov iders t hat off er t he BGP/ MPLS The pdat ed hav editeion t he ben establed - selling efds erence p rov ides cover of sit e VPN ualr eady an of MPLScor alle I Pinn one et w ornet k twhork at fing orwrar t raf fic f r om one custage om er essent ial an d cu t t ingedg e t ech nologies. t o anot her . BGP is used t o dist r ibut e t he VPN r out e infor m at ion acr oss t h e pr ovid er ' s core net w or k. Con cise v iewes18 of- t6,echn iesVPN essen t ial et wor k ingin pr ofession at all As illust r at ed ov in er Figur an olog MPLS cont aint os nt he follow g key com als ponent s: lev els, f rom nov ice t o ex pert . New ser chapt s ov include covwerag e of MPLSim por tenabled ant t opics like VoI( P) P and The viceerpr ider net or k has pr ovider r outEAP er s. The P rou t ers f or w ard t he VPN t r aff ic bet w een pr ov ider edge ( PE) r out er s. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age As it s n ame im p lies, a PE r out er is on t h e ed ge of t h e pr ov id er net w ork . I t con nect s t o Aut ored Cisco Sychang st ems, oring ldw ide orstking f oredg t hee I(nCE) t er nr et . er s. As show n custhom er by sit es t o ex e rw out inf orleader mat ioninwnet it hwcu omer out in Figur e 18 - 6, a PE rou t er can inv olv e m ult iple cust om er VPNs, w h ich hav e t h eir ow n I P I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat add ressin g an d rou t ing sch em es. This t r aff ic sep arat ion is achieved by m aint ain in g a Vir t ual enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Rou t ing and For w ar ding ( VRF) t able f or each cust om er ' s VPN. A VRF cont ains t he VPN t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing r out ing inf or mat ion f or a p art icular cu st om er VPN. Th e VPN r out ing inf or mat ion is indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . exchan ged bet w een t he PE r out er s using BGP. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, is acust comom plet an d u pe rvef er pence t o t he t ial t o all CE r outt heriss book pr ov ide ereaccess t ot ot hdeat ser ice rov ider n ettwop orics k . tAhat CEare r ouessen t er can net w or kin g p rof essionals, r egar dless of ex pert ise. exchan ge cust om er r out ing inf orm at ion w it h t he PE r out er using v ar iou s r out ing pr ot ocols. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Figu r e 1 8 -6 . BGP/ M PLS VPN Comp one nt s t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Thr ougPages: h t he11serv 28 ice pr ovid er MPLS cloud , VPN d at a t r af fic is f orw ar ded bet w een PE r out ers. Th e for w ar ding decision is m ade b ased on t w o sour ces of in for m at ion: a label f orw ar din g t able m aint ained by t h e P r out er ( also called a Lab el Sw it ch Rout er [ LSR] ) , an d a label car ried in t h e dat a pack et s. The MPLS lab els u sed t o m ak e f orw ar ding d ecision s ar e header s creat ed by LSR. The f or mat of The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t he lab els d ep en ds on t h e lin k layer t echnolog ies. For exam p le, ATM and Fr ame Relay can carr y essent ial an d cu t t ing- edg e t ech nologies. a lab el as par t of t heir lin k layer h ead er s—t he VCI or VPI f ield of t he ATM cell header , and t he DLCI f ield of t he Fr am e Relay header, respect ively. For lin k layer t echnolog ies t h at cann ot car r y a lab el in cise t h eirovlink lay er such Et her , kPPP, and Tokenals Ring a "lev sh im " label Con er v iew s ofheader t echns, olog ies as essen t ialnet t o, nFDDI et wor ing pr ofession at ,all els, f rom header is inser t ed b et w een t h e link lay er and net w ork lay er header s. The MPLS labels ar e nov ice t o ex pert . dist r ibut ed v ia a Label Dist r ibut ion Pr ot ocol ( LD P) . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP A d at a p ack et can carr y m ult ip le lab els in t he for m of a last - in - fir st - out ( LI FO) label st ack . I n t he case of BGP/ VPN, dattaechn packet s h ave lab el id age en t ifies t he rem ot e Cov eragMPLS e of cut t ingt he edge ologies lik et wo optlabels. ical n etThe wor kinn ingerand st or PE r out er t hat adv ert ises t he cu st om er r out e, an d t he out er lab el for w ard s t he dat a p acket t hr ou Aut gh thhe ored MPLS by Cisco cloud Sy t o st t he ems, PE w r out or ldw er . ide leader in net w or king f or t he I n t er n et . I n tFigur ern etew18 or -k6, in gassum Tech nologies e t hat r out Hand er CE_1 book , at Four W hit t h eEd VPN it ionSit , is e 2a ad com ver prt ehensive ises a r outrefer e 10ence . 1. 1/ t24 hatt o renables out er PE_ net1.w or PE_1 kin gadds p r ofessionals t his r out e t too un it sderst Wh itand e VPN an dVRF im plem t ableenand t cont assig emns poraarlabel y int er t o net t his w ork r outing e. t echnologies. This VPN rou t eMast andert ht ehelabel t er mar s,econ distcep r ib tut s,ed t echn t o PE_2 ologies, at t h ane dotdevices her endused of t hin e Whit t oday e 'VPN s netvia w ork BGP. ing indu st ry When host . Lear s atnWhit howe t VPN o incor Sitpor e 3atweant int er t onet com w or mukin nicat g t echn e w itolog h 10. ies 1. in 1/ t2o4,a itLAN/ s CE_2 WAN r out env erir fonm or w ent ard .s tCom he packet plet e wtit o hPE_2 new based an d u pdat on t ed he chapt VPN r er out s eonit secur lear ns it yfr, om st orPE_ age, 2. opt Upon icalr net eceivin w or kgint hg,e scalabilit pack et , PE_2 y, and sspeed, look up it s tVRF h is book t able.is The a com look plet upe indicat an d u pest ot hat d at10. e r ef 1 .1 er/ence 24 can t o bt he e r eached t op ics t hat v ia PE_ are 1. essen So tPE_2 ial t o all net w or insert s kin t heg cor p rof respon essionals, ding label r egar it dless lear of ned exfpert r om ise. PE_ 1 f or 10 . 1. 1/ 24 an d at t em pt s t o send t he d at a pack et t o PE_1 . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw Con t inuing ar e, pr t hot e ocols, discu ssion, and ser not v ices e t h at invt olv o r each ed . FuPE_1 ndam , anot ent alh er t ech looku nology p is inf p erorf orm mat ion ed tis o fpr ind ovout idedt he on a b r oad label associat r ang eedofwint it hegr t he al rsy out steem t os PE_ and1serv w it hices, in t hin e clud MPLS ingcore. det ailed Finally, descr PE_2 ipt ion sends s, rev t he iewdat quest a pack ions et t oiten w h tsu wo relabels. con cept The comp P r out r ehers en sion in t hand e MPLS r et enclou t ion, d sw and apad t he dit out ional er rlabel esou rtces o forf or w ar fudrtther h e pack st udy et.s Cov fr omerag PE_2 e ist oalso PE_1 ext . end When ed PE_1 n ot only get st ot he new pack n etetwor , itklook ing concep s at t het s, innbut er also lab el t o t o old m ak er ,e legacy t he syst for wem ar ding s, pr decision ovid in g at omtor hee rrigh ealist t CE ic rpict outur er e, such of t heasrealCE_w1.or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Becau seivVPN cust om use RFChelp 191ing 8 p rt he iv atreeader I P addr esses, ery possible haticient on e PE pr odu ct it y an d im prerovs ecan eff iciency, m ake morite is invt elligent , cost -t eff rdecisions out er m ight anage t work o cust for tm h eir net w s. om er VPNs t hat hav e ov er lapp in g addr ess sp aces. This is an issu e for BGP, w hich assu mes t h e global uniqu en ess of t h e I Pv4 add r ess it car r ies. To solv e t h is pr oblem , BGP/ MPLS VPN com bin es t he f ollow ing t w o mechanism s: I nt r odu cing t h e VPN- I Pv4 add ress t h at conv ert s t he n onuniq ue I Pv 4 ad dr ess t o a g lobally un iq ue ad dr ess f am ily . A VPN- I Pv 4 addr ess cont ains an 8- by t e r out e d ist ing uisher ( RD)

follow ed by a 4 - by t e I Pv 4 ad dr ess. Deploy m en t of m ult ipr ot ocol BGP ext ensions t o supp or t t h e dist r ib ut ion of t he VPN- I Pv 4 add ress. As show n in Figur e 18 - 6, in t he MPLS VPN, t he CE r out er s d ir ect ly peer wit h t h e PE rou t er s. Th is m odel is called t he peer mod el. Com par ed t o t he ov erlay m od el used by I PSec VPN, in w hich cust om er rou t er s p eer on ly w it h ot h er cu st omer r out er s t o for m p oin t - t o- poin t t u nnels t hat • of Content s creat e a " v irtTable u al back bone, " t he peer m odel scales m uch bet t er in a lar ge- scale d ep loy m ent . •

I ndex

IThe nt e rn w or adv k ing ant Te chnologie s H a ndbook otether ag e of MPLS VPN ,isFour in th t heEdit arion ea

of q ualit y of ser v ice ( QoS) . MPLS supp ort s classificat ion of Inc. packet s int o dif fer en t classes of ser v ices ( CoS) an d h andling of pack et s via By Cisco Systems, app rop riat e QoS char act erist ics. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

MPLS-Based Layer 2 VPN I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The I ETF PPVPN gr oup an d t he PWE3 g rou p ar e w or k ing t o d ef ine a fr am ew or k and st and ard s for pr ov ider- p r ovisioned Layer 2 VPN. Th e L2VPN let s t he serv ice pr ov id er pr ovid e Lay er 2 t ran sp or t for Lay er 2 ser vices, su ch as Et her net , Fram e Relay , and ATM, t o cust om ers over an I P/ MPLS back bone. Th is keeps t h e ser v ice p rov ider f rom hav ing t o m aint ain I P, Fr ame Relay , an d ATM net w or ks. I t also giv es ser vice pr ov iders a f easible m igr at ion pat h fr om Fr am e Relay and ATM The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of inf rast r uct ur es t o an MPLS- based I P inf rast r uct ur e w it hou t in t er r upt in g ex ist in g ser vices. essent ial an d cu t t ing- edg e t ech nologies. I n con t rast t o t he BGP/ MPLS VPN descr ibed in t h e pr ev ious sect ion, cust om ers wh o u se L2VPN need Con t o mcise anag t ing. oveert heir v iewow s ofn trou echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . The L2VPN fr am ew or k def in ed by I ETF PPVPN g rou p h as t w o m od els: New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Vir t ual Pr iv at e Wir e Ser v ice ( VPWS) im plem en t s a p oin t - t o- p oin t t op ology in w hich t h e PE Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age r out er s at each en d of t he pr ov ider core ar e conn ect ed by a " pseudo w ir e" ( PW ) . The Layer 2 prhot ocolby pay loads, as wFram e ide Relay an d in ATM, aror e king en capsulat Aut ored Cisco Sysuch st ems, or ldw leader net w f or t heed I n at t er tnhe et . in gr ess PE r out er and ar e f orw ar ded bet w een PE r out ers as pseudo- w ir e PDUs. This m odel h as t w o echnnologies olog ies: Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat I n t ernpr etom w orisin k inggt Tech enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing - Any Tr anspor t Over MPLS ( AToM) supp or t s t he t ran sp ort of any pr ot ocol, su ch as indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Fram e Relay , ATM, Et her net , PPP, or HDLC, over t he MPLS core net w ork . Th e Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, encapsulat ion and label dist r ibut ion m echan ism s ar e d ef ined u nder t w o gr oups of and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all I ETF d raf t s: Mar t ini dr aft s and Kom pella dr aft s. net w or kin g p rof essionals, r egar dless of ex pert ise. - L2TP ver sion 3 is used for t h e same pur pose ov er I P core net w ork s. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Vir t ual Pr iv at e LAN Ser v ice ( VPLS) im plem en t s an em u lat ed LAN br idge w h er e all t h e VPLS a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions PE r out ers are con nect ed. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary Ov er t he p ast f ew year s, VPN t echnologies hav e g row n dr am at ically . New VPN t echn ologies let ent er pr ise cust om ers sav e m oney b y using VPN t o t r ansfer dat a secur ely over t h e I nt er net an d let serv ice pr ovid er s of fer new p r ovider - pr ov isioned VPN serv ices t o ent er pr ise cu st om er s. The •un derly ing t ech Table of Content nologies pr sov ide dif fer en t char act er ist ics for v ar ious t y pes of VPNs t h at suit •v ariou s cust omer I ndex r equir em en t s. I PSec L2TP- based VPNs off er st r ong secu rit y ser vices and oft en Iar ntee rn w or k ing by Te chnologie s H acu ndbook , Four Edit ion metanaged ent er pr ise st omer s. th MPLSb ased Lay er 2 and Lay er 3 VPNs pr ovisioned by serCisco v ice Systems, pr oviderInc. s of fer lar ge- scale deploy m en t an d st r ong QoS m anagem en t . By Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What is a VPN?

2:

I ndex k ey secur it y ser v ices does I PSec pr ov ide? What

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : What By Cisco Systems, Inc.is 4:

t h e fun ct ion of t h e I KE p rot ocol?

I KE is a t w o- ph ase pr ot ocol. What does each ph ase accom plish?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

What ar e L2 TP's op er at ion m odes?

I SBN: 1- 58 705 -1 19 -2 Pages: 28 6 : 11How

d oes MPLS su ppor t hier ar chical r out ing in BGP/ MPLS VPN?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Davie, Br uce and Yak ov Rek ht er . MPLS Tech nology and Applicat ions . •

Table of Content s

•• Sch neier , Br uce. App lied Cr y pt ogr aph y. I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Inc. • Cisco RFC 2Systems, 401 , Secu rit y

Ar chit ect ur e f or t h e I nt er net Prot ocol .

Pub lish er: Cisco Press

• RFC 2 402 , I P Aut h en t icat ion Header . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

• RFCPages: 2 40611 , I 28 P En cap su lat ing Secur it y Pay load ( ESP) . • RFC 2 407 , The I nt er net I P Secur it y Dom ain of I nt er pr et at ion f or I SAKMP. The u pdat ed, Iedit ionet ofSecu t he rit b est - sellingion all-an in-done w ork ingent r ef erence ides cover • RFC 2 408 n t ern y Associat Keynet Man agem Pr ot ocolp rov ( I SAKMP) . age of essent ial an d cu t t ing- edg e t ech nologies. • RFC 2 409 , The I nt er net Key Exchan ge ( I KE) . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . • RFC 2 661 , Lay er Tw o Tu nneling Pr ot ocol " L2TP" . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP • RFC Cov 3 193 erag , Secu e of ring cut t ing L2TP edge usintgechn I PSec. ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . • I ETF Dr aft : dr aft - iet f - pp vp n- r fc25 47bis- 02 , BGP/ MPLS VPN. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing •t echnologies. I ETF Dr aft : Mast dr after - iett he f - pp vpmnf ram k, L2 VPN Framanew k. t er s,l2con cepew t s,ort echn ologies, d or devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, • Vir t u al Pr iv at e Net w or k Con sor t ium , ht t p: / / v pnc. or g. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Part IV: Multiservice Access Technologies Ch apt er 19 Voice/ Dat a I n t eg r at ion Technolog ies • •

Ch apt er 20 W ir eless Technolog ies Table of Content s

Ch apt er 21 D igit al Sub scr iber Lin e I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ch apt er 22 Cable Access Tech nologies

By Cisco Systems, Inc.

Ch apt er 23 I n t rod uct ion t o Op t ical Techn ologies

Cher: aptCisco er 24 VoI P Pub lish Press Pub Ch Datapt e: Sep 1 1,am 2 003 er tem 25ber D yn ic

Pack et Tr anspor t / Sp at ial Reuse Pr ot ocol

I SBN: 1- 58 705 -1 19 -2

Ch apt er 26 EAP

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 19. Voice/Data Integration Technologies • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Pr ovid e an over view of t echnolog ies an d ap plicat ion s of int egr at ed v oice/ d at a n et wor k ing.

By Cisco Systems, Inc.

Ou t lin e t he d iff er ences bet w een t he v ar ious v oice/ dat a int egr at ion t ech nologies, and t ell be u sed.

Pubwlish er: each Cisco Press hen should

Pub Dat e: Sep tem ber 1 1, 2 003

Under and he19specific pr ot ocols inv olved in v oice/ d at a n et wor k ing. I SBN: st 1- 58 705t-1 -2 Pages: 11 28

List sp ecific n et w or k eng in eer ing challen ges and solu t ions associat ed w it h t he int egr at ion of v oice an d dat a.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction Voice/ d at a int egr at ion is im por t ant t o n et wor k d esign er s of bot h ser vice pr ov iders an d ent er pr ise. Ser vice pr ov iders are at t ract ed by t h e low er - cost m odel—t he cost of p acket v oice is cur r en t ly est im at ed t o be only 20 t o 50 percent of t he cost of a t r adit ional cir cu it - based v oice •net w or k. Lik ew Table Content s ise,of en t er p rise net w or k designer s ar e int erest ed in dir ect cost savin gs associat ed •w it h t oll- by pass I ndexand t and em sw it ching . Bot h ar e also int er est ed in so- called " soft sav ing s" Iassociat nt e rn et wed or k wit ing hTerchnologie H a ndbook , Four th Edit ion mor e ef ficient net w or k cont r ol an d m anag em ent . educed smaint en ance cost s and Finally, p acket - based voice syst em s off er access t o n ew ly enh anced serv ices, such as Unified By Cisco Systems, Inc. Messag in g and applicat ion con t rol. These, in t ur n, pr om ise t o incr ease t h e pr oduct iv it y of users andPub diflish ferer: enCisco t iat ePress ser v ices. Pub Dat e: Sep tem ber 1 1, 2 003 I nt egr at ion of voice and d at a t echnologies has acceler at ed rap idly in recen t y ears becau se of I SBN: 705dem -1 19 -2 bot h sup ply-1- 58 and and - sid e int eract ions. On t he dem and side, cust omer s ar e lever aging Pages: inv est m ent 11 in28 n et wor k inf r ast ru ct u r e t o t ak e ad van t age of int egr at ed applicat ions, such as v oice app licat ions. On t h e supp ly sid e, v endor s h ave been able t o t ak e adv ant ag e of br eakt h rou ghs in m any ar eas, inclu ding st and ard s, t echn ology , and net w or k per for m ance.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Standards essent ial an d cu t t ing- edg e t ech nologies. Man y st andar ds f or int er oper abilit y for v oice sig naling hav e f in ally been r at ified and mat ur ed t o t he point of reasonable operolog abilit y . essen This rteduces t he r isk and cost s faced by all v en dor s off erin g Con cise ov er v iew s in oft er t echn ies ial t o n et wor k ing pr ofession als at lev els, f rom com ponent s of a v oice/ dat a syst em , and it also r edu ces t h e risk t o consum er s. St an dar ds, such nov ice t o ex pert . as H. 32 3 ( ap pr ov ed by t he I nt er nat ional Telecomm un icat ion s Un ion [ I TU] in Jun e 19 96) , are now ev olv in g t hrerough t h eir cov t h ird aned of f our h it ter at ions, wh ile VoI pr oduct s bEAP ased on in it ial st andar ds New chapt s include erag imt por ant t opics like P and st ill enjoy st r ong capab ilit ies and int er oper abilit y . Th e gener al m at ur it y of st and ard s has, in t ur n, generCov at ederag r obu ocoledge st ackt sechn t hatologies can b elikpur chased offwor t he sh elf " by vend e st of pr cutott ing e opt ical n"et k ing and st or ageors, f ur t her ensur ing int erop er ab ilit y . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Technology enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Recen van ces in t tech nology enwabled inolog t egries at ion dat a. For env ex am ple,ent new indu st tryad . Lear n how o incor por hatave e intalso er net or kin gv oice t echn in t w o itahLAN/ WAN ir onm . Digit al Sig nal Pr ocessor ( D SP) t echnology has allow ed analog signals t o be p r ocessed in t he Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, digit dom ain, h ich isw aascom dif ficult ossible earlier. pow er f ult ial n ewt o all and al speed, t h is w book plet e or anim d uppt o- d aton e rlyefaerfew enceyear t o tshe t op ics These t hat are essen chips of fer t r em en dous p r ocessin g speeds, allow in g voice t o be sam pled , dig it ized, and net w or kin g p rof essionals, r egar dless of ex pert ise. com pr essed in r eal t ime. Fur t h er b r eak t hr oug hs in t he t echn olog y allow as m any as four voice Reader conv er sat s wions ill obt t oain be amgan reat aged er un at der t hestsam an ding e t imofe LAN on aand singWAN le ch ip, n et w it orhk ev ing, enpgr areat t icuerlarply er tf h orm e an ce hardevelopm in dw ar e, prent ot ocols, . Th ese and t echnolog ser v icesies invgolv reat edly. rFu educe ndamt ent h e al cost t ech and nology compinf lexor it mat y of ion devis elop pr ov in gided on a bodu pr r oad ct sr ang and edeploy of int egr ingalvoice sy st em ov er s and dat aserv solut ices, ion s. in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ICov n oterag her eariseas, e indu st ryn ot has alsot oenj oyed eak t h rou ghs int s,v oice cod ec coder er, / legacy decoder ) alsot hext end ed only new n etbr wor k ing concep but also t o( old tsyst echnology Pr eviou it ewas assum ed ur t hat qu alit wident t h was em s, pr. ovid in g aslym, or r ealist ic pict e ofvoice t he realw yorw ldould n et wsu orffker ingasenband vir onm s in w hich decreased in aoper r elat linear ionelines . Howf ev , new , sophist icatper ed algor it hm swem ployease ed in pr of essionals atively e. Tools andfash gu id or er opt im izing syst em for m ance ill incr new chan ged t hiciency, at v iew. help I t ising now le tm o ake ob t ain in g voice pr oducodecs ct iv it y hav an de im pr ov e eff t hepossib r eader morr eeasonably in t elligentg,oodcostsound - eff icient at a f ract ion t he net b andw decisions for of t h eir w orkidt s. h on ce r equ ir ed. More im p ort an t ly, t hese new algor it hm s h ave b een incor por at ed int o t h e st andar ds t o allow int er oper abilit y of highly com pr essed voice.

Network Performance

Finally, d at a- net w or kin g t echn olog y has im pr ov ed t o t he p oint t hat voice can be carr ied reliably . Ov er t he last few y ear s, g row t h in voice t r af fic has been r elat iv ely sm all, w hile dat a t r aff ic has gr ow n ex pon en t ially . Th e r esult is t hat dat a t r aff ic is now g reat er t h an v oice t r aff ic in m any net w or ks. I n add it ion , t he relat iv e imp ort ance of dat a t r affic has gr ow n, as businesses an d or ganizat ion s com e t o base m or e bu siness pr act ices an d policies on t he u biqu it y of dat a net w or ks. Th is increase in im p ort an ce of dat a net w ork s h as for ced a fun dam ent al chan ge in t he w ay dat a net w or ks are en gineer ed, b uilt , and m anag ed . Ty pical " best - effor t " dat a m odelin g h as giv en w ay t o Table adv anced p olicy - based n et wor k ing w it h man aged q ualit y of ser v ice t o sup por t an • of Content s even gr eat er ran ge of app licat ions. Voice t r af fic, as an applicat ion on a dat a net w or k, has • I ndex benefit ed gr eat ly fr om t h ese t echnolog ies. For exam p le, sup por t of d elay - sen sit iv e SNA t r af fic I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion ov er I P net w or ks r esult ed in br eakt hr ough s in lat ency m anag em ent and qu eu in g pr ior it izat ion, By Ciscower Systems, w hich e t henInc. app lied t o v oice t r aff ic. As st atlish eder:prCisco ev iously, Pub Press deploy ment of new t echnolog ies an d ap plicat ion s m ust also b e dr iv en by gr eat er dem and om Pub Dat e: Sep temfr ber 1 1,u2ser 003s. Break t hr oug hs in t ech nology d on't necessar ily r esult in incr eased deploy Im en t u nless t h ey fill a real u ser n eed at a r easonab le cost . For ex am ple, digit al au dio t ape SBN: 1- 58 705 -1 19 -2 ( DAT) t ech nologies nev er enj oy ed w idespr ead use ou t sid e t he au dioph ile com m unit y b ecause of Pages: 11 28 t he high cost and only m ar ginally b et t er p er ceiv ed perf or man ce t han analog t apes. Voice/ dat a int egr at ion, how ev er , pr ov id es user s w it h v er y r eal benef it s, b ot h now an d in t h e fu t ur e. Most users of voice/ dat a in t egr at ion t echn olog ies g ain in t w o w ay s: Pack et v oice t echn olog ies ar e less exp en siv e, and , in t he f ut ur e, t hey w ill of fer m uch gr eat er cap abilit ies com par ed t o t oday ' s circuit - b ased v oice sy st em s. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Economic Advantages Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom ice est t o ex I t h asnov been im pert at ed. t h at pack et v oice net w ork ing cost s only 20 t o 30 per cent of an eq uiv alent circuit - b ased v oice n et w or k . This is t ru e for bot h car r iers ( ser vice pr ov iders) and ent erp r ise New chapt s include cov im erag e oft hat im por opics likecan VoI oper P and EAP ( pr iv at e) user s. er Logically , t his plies entt ant er prtise users at e long - dist ance voice ser v ices b et w een f acilit ies at less cost t h an p ur ch asin g lon g- dist ance v oice ser vices fr om a Cov eragite's of echn lik eent opt n etuser worsk ing and st or ageint egr at ed carr ier , and oftcut en t ting r ue.edge For tex am ologies ple, m any erical pr ise h ave deployed v oice/ dat a t ech nologies t o t ran sp or t v oice- ov er- d at a w ide- ar ea net w or ks ( WANs) bet w een Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . t r adit ional PBXs acr oss dif fer en t g eog rap hical locat ion s. The r esu lt ing sav ing s in lon g- dist ance t oll char ges of t en p rov ide p ayb ack in as lit t le as six m ont hs ( especially if int ern at ional calls ar e I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat av oided) . Usin g d at a sy st em s t o carr y v oice as " v irt u al t ie lines" bet w een sw it ches is also useful enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t o ser vice pr ov ider s. I n f act , man y carr iers hav e st art ed t o em br ace pack et - based v oice t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t echnologies as t h eir p r im ar y net w or k inf rast r uct ur e st r at egy g oin g for w ard . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, How ev er , saving s associat ed wit h p ack et v oice t echn ologies don' t st op w it h sim ple t r an sp ort . I t and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all is also possible t o sw it ch voice calls in t h e dat a dom ain mor e econom ically t h an t rad it ion al net w or kin g p rof essionals, r egar dless of ex pert ise. circuit - b ased v oice sw it ches. For lar ge, m u lt isit e ent er pr ises, t he sav ing s result fr om using t h e dat a net w or k t o act as a " t andem sw it ch" t o r out e v oice calls b et w een PBXs on a call- b y- call Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e basis. The r esult ing voice net w or k st r uct ur e is simp ler t o adm inist er and uses a rob ust , har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on non blocking sw it ch ing fab ric m ade up of dat a sy st ems at it s cor e. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Advances in Applications Real cost sav ings ar e suf ficien t f or deploy m en t of v oice/ d at a int egr at ion t ech nologies. How ev er, t her e ar e add ed benef it s, wh ich w ill become mor e ev ident in t h e fu t ur e. As applicat ions ev olve, or ganizat ion s w ill gain in cr eased user pr odu ct iv it y f r om t he in t eg rat ion of v oice and com p ut er •app licat ions. Table ofut Content s hony in t eg r at ion ( CTI ) w as begu n by pr iv at e br anch ex chan ge Comp er t elep •( PBX) vend ors I ndex in t h e 198 0s t o int egr at e com put er s w it h PBXs t o p r ovide applicat ions, such as Iadv nt e rn et w or call k ing cent Te chnologie a ndbook , Four th le, Edit" ion anced er f eatsuHr es ( f or ex amp scr een pop s" for agent s) . By Cisco Systems, Inc.

How ev er , as v oice/ dat a int egr at ion cont inues, t h e lin e bet w een v oice an d dat a ap plicat ion s w ill cont inu e t o b lur . For exam ple, Unified Messaging sy st em s ar e now available t hat com bin e voice Pub lish er: Cisco Press m ail, e- mail, an d f ax m essaging int o a sing le, con venient sy st em. Wit h t hese adv anced syst em s, Pub Dat e: Sep tem ber 1 1, 2 003 users can h ave e- m ail r ead t o t hem ov er t he phone or can ad d docum en t at t ach ment s t o v oice I SBN: 58 705 m ail. At t h e1-ent erp-1r 19 ise-2 level, n ew applicat ions, such as vir t ual call cent er s, allow call cen t er 28 rib ut ed any wh er e w it h in r each of t h e dat a net w ork , w h ile st ill r eceiv in g t he f ull agent sPages: t o b e11dist suit e of call cen t er fu nct ions and f eat u r es. Th ey can even r eceiv e calls ov er t heir com p ut ers r at her t h an u sin g a t r adit ional t elephon e inst r um en t , an d t h ey can pr ov ide " b lend ed cont act cen t er" supp ort t o an swer Web user qu est ions w it h elect r onic chat capabilit y and e- m ail bet w een v oice calls. These cap abilit ies g o f ar bey ond sim ple cost sav ings and w ill ult imat ely m ak e or ganizat m uch e eff ect-ivselling e and allpr ofinit able. The u pdation ed sedit ion m ofort he b est one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The st r ong p ressu res d riv ing t he in t eg r at ion of v oice and dat a net w ork s h ave result ed in v ar iou s solut ions t o t he pr oblem , each w it h it s own st r engt h s and w eak nesses. Th ree g en er al ap pr oach es exist :Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Voice over er ATM New chapt s include cov erag e of im por t ant t opics like VoI P and EAP Voice over amteing Relay Cov erag e ofFrcut edge t echn ologies lik e opt ical n et wor k ing and st or age Voice overby I PCisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Aut h ored Ther e et arwe or also ixed nologies solu t ions, including v oicet hover P, ,ov ampre ehensive Relay , and so ence on . These I n t ern k in gmTech Hand book , Four Ed it Iion isera Fr com refer t hat ar e illust rat ed in Figur e 19 1. Th e figu re sh ow s t hat voice ov er ATM an d voice ov er Fr am e Relay ar e enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing pr im arily t r an sp ort m echan ism s b et w een PBXs, w h ile v oice ov er I P can conn ect all t he w ay t o t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing tindu he desk e det ar epor available erw in t hisg chap st ry .t op. LearMor n how t oails incor at e int erlat net or kin t echnt er. olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

Figu r e 1 9 -1 . M i xe d Solu t i on s I ncl ud in g Voi ce ove r I P, Voi ce ove r Fr am e

Reader s w ill obt ain a g reat er un der st Re an ding LAN WAN la y ,ofan d and so on . n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

New World Voice Technologies Voice over ATM ( VoATM) can b e su ppor t ed as st andar d pu lse code mod ulat ed ( PCM) voice v ia circuit em u lat ion ( AAL1, describ ed lat er) or as v ar iable bit r at e voice in ATM cells as AAL2 ( also descr ibed lat er ) . ATM of fer s m any adv ant ages for t ran sp ort and sw it ch ing of voice. Fir st , q ualit y •of ser v ice ( QoS) Tablegof Content s can b e sp ecif ied by serv ice pr ov isionin g or on a per - call basis. I n uar ant ees •add it ion , callI ndex set u p sign alin g for ATM sw it ch ed v irt u al circuit s ( SVCs) , Q. 29 31, is based on call Iset nt eup rn etsig w or k ing Tefor chnologie H a ndbook , Four th Edit ion r at ion is sim ilar t o cir cuit - based v oice net w or ks. naling v oice sI SD N, Q. 93 1. Adm inist By Cisco Systems, Inc.

How ev er , VoATM su ffer s f rom t he b ur den of ad dit ional com plex it y and incomp let e su ppor t and int er operab ilit y amon g vend ors. I t also t en ds t o be m or e exp en siv e b ecause it is orient ed t ow ar d Pub lish er: Cisco Press all opt ical n et wor k s. Most im por t an t ly, ATM is t y pically deploy ed as a WAN Layer 2 pr ot ocol an d, Sep tem ber 1 1, 2 003 t herPub eforDat e,e:does not ext end all t h e w ay t o t he desk t op. Nev er t heless, ATM is qu it e ef fect ive for I SBN: 58 705 19 -2 t an dem- sw it ching ser v ices b et w een ex ist in g v oice swit ches an d PBXs. pr ov iding t r1unk ing-1and Pages: 11 28

Voice over Fr am e Relay ( VoFR) h as becom e w idely deploy ed acr oss m any net w or k s. Like VoATM, it is t yp ically emp loyed as a t ie t ru nk or t andem - swit chin g f un ct ion bet w een r emot e PBXs. I t benefit s fr om m uch sim pler ad min ist r at ion and r elat iv ely low er cost t h an VoATM, especially w hen deploy ed ov er a pr iv at e WAN n et wor k . I t also scales m ore econom ically t h an VoATM, supp in gedlinedit ks fion r omofT1 dow n t- oselling 5 6 Kballps.inWhen deploy eding ovrer a car efully eer edage Fr ame The uort pdat t he b est one net w ork ef erence p rovengin ides cover of Relay net w or k, VoFR w or ks ver y w ell and pr ovid es good qualit y . How ever , v oice q ualit y ov er essent ial an d cu t t ing- edg e t ech nologies. Fram e Relay can suff er dependin g on n et w or k lat ency and j it t er . Alt h ough m inim al ban dw idt h and bu r st in ess ar e r out inely cont r act ed, lat ency and j it t er are of t en not in clu ded in ser v ice lev el agr eem ent s ( SLAs) w itsh of sert echn v ice olog p rovies ideressen s. As t aialr esult , vwor oice perfprorofession man ce als can at v ary Even Con cise ov er v iew t o n et k ing all .lev els, iff rom qu alitnov y isice good at pert f irst., voice qu alit y can degr ade over t im e as a ser v ice p rov ider 's n et wor k t o ex becom es sat u rat ed w it h mor e t r af fic. For t his r eason, m any lar ge ent er pr ise cust om er s ar e beginn New ing chapt t o specify er s include lat encycov and erag j it teerof , as im w por ellt ant as over t opics all like packVoI et P t hrand ougEAP hpu t f r om carr iers. I n t hese sit uat ions, VoFR can p rov ide ex cellen t serv ice. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Voice over I P ( VoI P) has b eg un t o b e deploy ed in r ecent year s as w ell. Un lik e v oice over Fr ame h ored Cisco Sy stVoice ems, ov w or net wion or king t heerIsn m t eruch n et .m ore value and RelayAut and Voicebyover ATM, er ldw I P ide is a leader Lay er 3in solut , andf or it off ut ilit y b ecause I P g oes all t he w ay t o t he desk t op. This m eans t h at in addit ion t o pr ovid in g b asic n t ern or k int and g Tech Hand book t h EdVoI it ion is aact com pr ehensive encet hose t hat PBXs tI ie t r unetkwand em -nologies sw it ching fu nct ions, Four t o PBXs, P ,can u ally b eg in t o refer r ep lace enables net w or kin gAsp raofessionals t o ion, un derst an dt able im plem t cont int er net w ly orkov ing as an app licat ion. Layer 3 solut VoI and P is rou an dencan be em carpor r iedartyr anspar ent er t echnologies. Mast er int he t err m cep t s, t echn d devices used Of in tall oday ing any t yp e of net w ork fr ast ucts,urcon e, including botologies, h Fr am eanRelay and ATM. t he' spnet ackwetork v oice st ry . Lear VoI n how t o incor por at er net or kintgimt echn t o a LAN/ WAN env se ir onm ent . tindu echnologies, P has perh aps t hee int m ost difwficult e supolog por ies t inginvoice qu alit y becau QoS Com pletbe ew h new an dNor u pdat chapt s onsuch securas it yTCP , st or age,in opt ical k in g, scalabilit y, cannot g it uar ant eed. m aledapp licater ions, r unn g on I P,net arw e or insensit ive t o andency, speed, book a comlost plet e an detuspt o- dt oatcollisions e r ef er ence o t he t op t hat are lat butt hmisust r et ris ansmit pack due or tcon gest ionics . Voice is messen uch mt ial or et o all net w rof essionals, r egarpack dless ex pert ise.it ion t o nor m al t r aff ic congest ion, QoS for VoI P sen sitorivkin e tgo ppacket delay t han et of loss. I n add is of t en depend en t on low er layer s t hat ar e ignor ant of t he voice t r aff ic m ingled wit h t h e dat a Reader t r aff ic. s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Voice Networking Basic voice t echnology has been available f or m or e t han 10 0 y ear s. Dur ing t hat t im e, t he t echnology h as m at ur ed t o t h e point at w h ich it h as become ubiqu it ous and lar gely inv isible t o m ost user s. This leg acy of slow ev olut ion cont inues t o aff ect t oday ' s adv anced v oice net w ork s in •m any w ay s, Table of Content so it is im por t san t t o un derst and t h e fu ndam ent als of t r adit ion al v oice t echnolog y •befor e em ulat I ndex ing it on d at a n et w or k s. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Tr analog By adit Ciscoional Systems, Inc. t elephon e inst r um en t s used for p lain old t eleph one serv ice ( POTS) use a simp le t w o- w ir e in t er f ace t o t h e net w ork . Th ey rely on an in t ern al t w o- w ir e/ f our - w ire hy br id circuit t o com bine bot h t r ansm it and r eceive sign als. This econ om ical ap pr oach h as been Pub lish er: Cisco Press eff ect iv e but r equir es sp ecial eng in eer ing r eg ard in g echo. Not e t hat t he cost an d cab lin g r equ ir ed e: Sep tem ber 1 1, 2 003 r ulePub outDatt he id ea of r unn in g a f our - w ir e cir cu it t o t he sub scr iber' s p rem ises f rom t he local I SBN: 19 -2 exchan ge; t1h 58 er 705 efor-1e, t he final mile t o t he sub scr iber is v ia hy br id filt er circuit s, w h ich per mit 11 28 lex sign als in each direct ion t o shar e t h e same t wo- wir e local loop. un iq uePages: f ull- dup Hy br id echo is t he pr im ar y sour ce of echo generat ed fr om t he pu blic sw it ch ed t elep hone n et wor k ( PSTN) . Th is elect rically gener at ed echo is cr eat ed as v oice sig nals ar e t r ansm it t ed acr oss t he net w or k v ia t he hy br id conn ect ion at t h e t w o- w ir e/ f our - w ire PSTN conv er sion p oint s r eflect in g elect gy ion t o t hofe tspeaker f rom t he - w irenet cirwcuit Ther efsign al pat h b ides et w een t wage o of The ur ical pdaten ederedit he b est - selling all-f our in- one ork.ing erence p rov cover tessent elep hones, inv olving a call ot her t han a local one, r eq uir es am p lif icat ion using a four w ir e cir cuit ial an d cu t t ing- edg e t ech nologies. in t he PSTN. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom novTelephony ice t o ex pert . Basic New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Thr ee t y pes of sig naling ar e r eq uired for t r adit ional t elephon y: super vision, aler t ing, an d add ressin g. Su ision onit or s t h eologies st at e of inical st runment —for am st ple, allow ing t h e cent ral Cov erag e perv of cut t ingmedge t echn likteheopt et wor k ingex and or age off ice or PBX ( a digit al or analog t eleph one sw it chboar d locat ed on t he sub scr iber pr em ises and used Aut t o connect iv at e Sy an d p ublicwtor elephon net w orinks) t ow kornow t h eI nreceiv h ored byp rCisco st ems, ldw ideeleader net kingwfhorent he t er n eter . has been pick ed up t o m ake a call, or w hen a call is t erm inat ed . Aler t ing concern s t he n ot ificat ion of a user n t ern w orisk pinrgesent Tech (nologies book Four h Edess it ion , is adur com refer tI hat a et call rin ging) Hand or simp le ,call prt ogr t ones ingpraehensive call ( su ch as ence b usy,t hat kinon) g p. rFinally, ofessionals o un derst and plem t cont em por ar intsion er net renables ingb acknet , anwdorso addrt essing enab lesant hdeim user t oen d ial a specific exyt en . w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Iindu n addit t o nsign alin t elephony vices prgovt echn ide molog edia anspor t for WAN t he v env oiceiritonm self,ent . st ryion . Lear how t og,incor por at e ser int er net walso or kin iest r in t o a LAN/ analogconan ver , bond ing and gr oun ding saf et y, opt pow er ,net anwd or a kvin arg, ietscalabilit y of ot h er Com plett eo-wdigit it h al new d sion u pdat ed chapt er s on secur it y ,for st or age, ical y, fu nctspeed, ions w ht hen and is needed. book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Analog v oice int er f aces hav e ev olv ed over t h e y ear s t o pr ov id e for t hese basic fun ct ion s w hile add ressin ecific ionun s. der Because basic POTSand t w ow iren analog in t erf Reader s wgillspobt ain ap a gplicat reat er st an ding of LAN WAN et w or k ing, p aces ar t icuop larerlyatt e h ein a m ast / slave mod el, tand wo basic t y pes int er faces e necessary f ormat dation a equip ment har dwerar e, pr ot ocols, ser v ices inv of olvanalog ed . Fu ndam ent al ar t ech nology inf or is pr ov idedt oon emu lat e:r ang t he euser side and he n setand w or kserv side. Thein user sidedet ( tailed eleph descr one) ipt ex pect t o riew eceiv e pow er a b r oad of int egr al sytst em ices, clud ing ion s,s rev quest ions fr t he or k as w ellr eh asensup er vand ision. t oom en su renet conwcept comp sion r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy A f orem eigs,n pr exovid ch ange FXS) ic intpict er f ace sedrealt o con eleph one,ent fax machin syst in g aser mvice or e r( ealist ur e is of ut he w ornect ld n an et wanalog or k ing ten vir onm s in w hiche, m , or any ot her ice and t h at gu w ou ld b e con edizing t o a syst ph one Itm out pu t sw 48 v dcease p ow er , pr odem of essionals oper at e. dev Tools id elines f or nect opt im em line. per for ance ill incr rpringing so don and it eff accept s d ialed digitt s. opposit e of ane FXS int er face is -aeff for eig n odu ct, ivand it y an im, pr ov e iciency, help ing he The r eader m ake mor in t elligent , cost icient exchan ge for of fice ( FXO) t ers.f ace. I t is used t o connect t o a sw it ching syst em pr ov iding ser v ices decisions t h eir net winork and super v ision, and it ex pect s t he sw it ch t o pr ov id e super vision and ot her elem ent s. ( Wh y " f oreign" ? The t er m s FXS an d FXO w er e or iginally used w it h in t elephone com pan y net w or ks t o descr ibe pr ovision of t elephon e ser v ice f r om a cent r al of fice ot her t han nor m ally assigned. ) Wit hin FXS and FXO in t erf aces, it is also necessary t o em ulat e v arian t s in su perv ision . Ty pical t elep hones oper at e in a loop- st ar t m ode. The t elephon e nor m ally p r esent s a high im pedance

bet w een t h e t w o w ir es. W hen t h e r eceiver g oes of f- h ook, a low - im pedance closed cir cuit is creat ed bet w een t he t w o w ires. The sw it ch, sensing cur rent f low , t hen k now s t hat t he r eceiv er is off - hook and applies a d ial t one. Th e sw it ch also check s t o be sur e t h at t h e r eceiv er is on- hook befor e sendin g a r in ging signal. Th is sy st em w or ks w ell f or sim p le t eleph ones, but it can cau se pr oblem s on t r unk s bet w een PBXs an d COs w it h high act iv it y . I n t hat sit uat ion, t he r emot e en d and t h e CO sw it ch can b ot h t ry t o seize t he line at t he sam e t im e. This sit uat ion , called glare, can fr eeze t h e t r unk unt il one side r eleases it . The solut ion is t o sh ort t ip or r ing t o g rou nd as a signal for lineTable seizur e r at her t han loopin g it . This is called gr ound st ar t . • of Content s •

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Aft er t he line is seized , it is n ecessar y t o dial t h e num b er . Nor m al hu man f inger s cannot out r un I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion t he dial r eceiver s in a m oder n sw it ch, b ut digit s d ialed by a PBX can. I n t hat case, m an y analog By Cisco Inc. st ar t or win k st art m et hod t o n ot ify t h e calling dev ice wh en t h e swit ch is t r un ks uSystems, se a delay r ead y t o accept digit s. Pub lish er: Cisco Press

AnotPub h erDatanalog in t erf ace oft en used f or t r un king is E&M. This is a f our - or six - w ir e int er face t hat e: Sep tem ber 1 1, 2 003 includes separ at e w ires f or super v ision in ad dit ion t o t h e v oice p air . E& M st an ds f or " ear and I SBN: 1- 58 705 -1 19 -2 m out h " or " Ear t h an d mag net o" an d is deriv ed f r om t he ear ly t eleph ony d ays. Th e E& M leads ar e 11 28 used tPages: o signal on- hook and off - hook st at es. Analog v oice w or k s w ell for b asic t r u nk connect ions b et w een sw it ches or PBXs, bu t it is un econom ical w hen t he n um ber of connect ions ex ceeds six t o eigh t cir cu it s. At t h at poin t , it is usually m or e eff icient t o use d igit al t r un ks. I n Nor t h Am er ica, t he T1 ( 1. 54 4 Mbps) t r unk speed is used, consist sat ions. oterence her parpt rov s ofides t he cover w or ldage , E1 of The u pdat ed ing editof ion24of digit t he ized b est -analog selling voice all- in-conv one er net w ork ingI nr ef (essent 2. 0 48ial Mbps) is tused t o carr y 3 nologies. 0 v oice chann els. ( En gineers refer t o t he adopt ion of E1 and T1 an d cu t ing- edg e t ech int er nat ionally as " t he baseball r ule" —t her e is a st r on g cor r elat ion of count r ies t hat play baseball t o t he u se of T1 . Ther ef or e, t he Unit ed St at es, Canada, and Japan hav e t h e larg est T1 n et wor k s, cise ov er iewusseofE1. t echn w hile Con ot her coun t rvies ) olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . The f ir st st ep in conv er sion t o digit al is sam p lin g. Th e Nyq uist t h eor em st at es t hat t he sam pling New er bs einclude por t est ant desir t opics P andEar EAP fr equ en cy chapt shou ld t w ice tcov he rerag at e e ofof t him e high edlike f r eqVoI uency. ly t eleph ony eng in eer s decided t h at a r ange of 4 000 her t z wou ld b e suff icient t o cap t ur e hu man v oices ( w h ich m at ches Covorerag cut t ing edge t echn ologies likore, e optv ical et annels wor k ingarand st or ageat a r at e of 8 000 t he perf maneceof of lon g analog loop s) . Theref oicench e sam pled t im es per second , or once ev er y 1 25 µ. Each of t h ese sam ples con sist s of an 8- bit m easu r em ent , h ored by00Cisco ems, or ldw ideAs leader in st net w or king f oring t heisI nused t er n et for a Aut t ot al of 64, 0 bpsSy t ostbe t ranwsm it t ed. a f inal ep, com pand t o. pr ov ide gr eat er accu racy of low - am plit ud e com p onent s. I n Nor t h Am erica, t h is is m - law ( Mu- law ) , w hile I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat elsew her e it is t y pically A- law. For int ern at ional int er net w or kin g p ur poses, it is agr eed t h at t h e enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Nor t h Amer ican side w ill m ak e t he conv ersion. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry LearanT1 how incorels porar at ee assem int er net w orfor kin g olog t o ps, a LAN/ env ir onm To con st.r uct , 24t ochann b led a tt echn ot al of 1. ies 536inMb and WAN an add it ion al 8ent bit. s Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, ar e add ed ever y 12 5 µ f or fr am ing, r esult ing in a r at e of 1 .5 44 Mbp s. Oft en , T1 fr am es are and speed,intthoislar book is rauct com plet e an dSuper u p- t oat eesr ef er ence o t he t hat essen t ialest o( 24 all com bined ger st ur es called Frdam ( 12 f ram tes) andt op Exics t end ed -are Super Fr am net w or kin g p rof essionals, r egar dless of ex pert ise. fr am es) . Addit ion al sig naling can t h en b e t r ansmit t ed by " rob bing bit s" fr om t he in t erior f r ames. Reader sw ill obt a gaces reat er der ding ion of LAN or ks ing, ly tbhite Basic T1 and E1 ain int erf emun ulat e st a an collect of anand alogWAN v oicen et t rw unk an d puar set icu roblar bed har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr oveach ided on signaling t o t ran sfer super visor y inf orm at ion sim ilar t o t he E&M analog m odel. As such, a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions chann el car r ies it s ow n sign alin g, an d t he int er face is called chann el associat ed t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e (is also. A extmend n ot only t ohod newuses n et wor k ing concep t s, butchalso t o fold signaling CAS) or eed ef ficient m et a com m on sig naling annel or er all, tlegacy h e v oice syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm in wmhich chann els. Pr im ary Rat e I nt er face ( PRI ) for I SDN is t he m ost com m on ex am ple of tent h isscom on pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease chann el sig naling ( CCS) . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions fora tin h eir w ork I f voice/ dat t egrnet at ion is s. t o be su ccessf ul, all of t h ese v oice in t erf aces m u st be sup por t ed t o pr ov ide t h e w id est possib le ran ge of app licat ions. Over t h e y ear s, user s hav e gr ow n t o ex pect a cer t ain lev el of per for m ance, r eliabilit y , and behav ior of a t elecomm u nicat ion s syst em , w hich m ust b e supp ort ed going f orw ar d. All t hese issues h ave b een solved by v ar iou s pack et v oice syst em s t oday so t hat user s can enjoy t he sam e lev el of supp ort t o w hich t h ey hav e becom e accu st omed.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Voice over ATM The ATM For um and t h e I TU hav e specif ied dif fer en t classes of ser v ices t o r ep resen t d iffer ent possible t r aff ic t y pes for VoATM. •Desig ned pr imar Tableily of for Content s com mu nicat ions, const ant bit r at e ( CBR) and var iable b it r at e ( VBR) voice •classes hav e Ipr ndex ov ision s for p assing r eal- t im e t raf fic an d ar e suit ab le for g uar ant eein g a cer t ain Ilevel nt e rn of et wserv or k ing chnologie s H at ndbook Four th Edit ice.TeCBR, in par icular ,, allows t heion am oun t of b andw idt h , end- t o- en d d elay , an d d elay vByariat ion t o be specif ied d ur in g t he call set up. Cisco Systems, Inc.

Desig ned pr incip ally for b ur st y t r aff ic, u nspecif ied bit r at e ( UBR) an d av ailable bit r at e ( ABR) ar e lish er: Cisco Press m orPub e su it able f or dat a applicat ions. UBR, in par t icular, m akes no gu aran t ees ab out t he deliver y Pub Dat e: of t he dat a Sep t raftem fic.ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

The mPages: et hod11of28t r anspor t ing v oice ch annels t hr ou gh an ATM net w or k depend s on t he n at ur e of t he t raf fic. D if fer en t ATM adap t at ion t yp es hav e been dev elop ed f or dif ferent t r aff ic t y pes, each w it h it s benefit s an d det rim ent s. ATM adapt at ion lay er 1 ( AAL1) is t he m ost com m on adapt at ion lay er u sed w it h CBR ser vices. Unst r uct ur ed AAL1 t ak es a con t in uous bit st r eam and places it w it hin ATM cells. This is a The u pdatmed of t he tbinest net w p rov cover of com mon et edit hod ion of suppor g -aselling fu ll E1allby int e one st r eam fr ork om ing endr ef t oerence en d. Th e prides oblem w itage h t his essent ial an d cu t t ingedg e t ech nologies. app roach is t hat a f ull E1 may be sen t , r egar dless of t h e act ual n um ber of v oice ch annels in use. ( An EI is a w ide- area digit al t ran sm ission sch em e u sed pr edom inant ly in Eu rop e t hat carr ies dat a at a cise r at eov ofer2.v04 ) olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Con iew8sMbps. of t echn nov ice t o ex pert . St r uct ur ed AAL1 con t ains a point er in t he p ayload t hat allow s t he d igit al signal lev el 0 ( DS0) st r uctNew ur e tchapt o be m ained cov in sub seq This allows w ork ef ficien eraint s include erag e uent of imcells. por t ant t opics likenet VoI P and EAP cies t o be gain ed by not using ban dw idt h for unu sed DS0s. ( A DS0 is a f r aming specificat ion u sed in t ran sm it t ing digit alCov sigerag nalseov a tsingle chan nel at 64 Kbps T1 nfacilit ofercut ing edge t echn ologies lik e on optaical et wory .k)ing and st or age The r em op Cisco t ion allow t h e ATM n etide worleader k t o t erm inatweorstking ru ct uf or r edt he AAL1 cells Autappin h oredg by Sy stsems, w or ldw in net I n t er n et .an d rem ap DS0 s t o t h e pr oper d est inat ion s. This elim inat es t h e need f or per m anent v ir t ual cir cuit s ( PVCs) bet w een y gpossible sour ce/ d estbook inat ion com ajor diff er encerefer f romence t he tphat rev iou s I n t ern et wev orer k in Tech nologies Hand , Four t hbinat Ed ition. ion , The is a m com pr ehensive app roach is t hat a PVC is n ot bu ilt acr oss t he net w or k fr om ed ge t o ed ge. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, VoATM Signaling and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Figur e 19 - 2 d escr ibes t he t r an sp ort m et hod, in w hich voice signaling is car ried t hr ough t h e net w or ks w t r ill anspar entalyg. reat PVCs cr eat edding for of botLAN h sigand naling and oice ran sp ortt icu . Fir Reader obt ain er ar uneder st an WAN n etv w or kting, p ar larstly, at hsig e naling m essage is car r ied t r anspar ent ly ov er t he sign alin g PVC f rom en d st at ion t o en d st at ion. Second har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on , coord inat ion bet w een t he end sy st em s allow s t he select ion of a PVC t o car r y t h e voice a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions com ion b etcomp w eenr eh end at ions. t o enmu su nicat re con cept enst sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Figu -2pr. ov The eeffVoATM Siging nat he li ng Tr an spor t M ode l De, scr th e pr odu ct iv itryean1d9im iciency, help r eader m ake mor e in t elligent costibe - eff s icient Tr an spor t Mnet e twhork od, decisions for t h eir s. i n W hich Voice Sig na li ng I s Ca r r ie d Th r ou gh t h e

Ne t w or k Tr a nspa r en t ly

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. At no t im e is t h e ATM net w ork p ar t icipat in g in t h e int erp r et at ion of t he sig naling t hat t akes p lace bet w een end st at ions. How ever , as a value- ad ded f eat ur e, som e p rod uct s ar e capable of Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom un derst an ding CAS and can pr ev en t t h e sen ding of em p t y v oice cells wh en t h e en d st at ion s ar e nov ice t o ex pert . on- h ook. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Figur e 19 - 3 sh ows t he t r anslat e m odel. I n t his m odel, t h e ATM n et w or k int er pr et s t h e sig naling fr om Cov bot herag nonw or kologies devices. ar encr betand w eenst or t heage en d st at ion s and e ATM of cutand t ingATM edgenet t echn lik ePVCs opt ical eteat wored k ing t he ATM n et w or k . This cont r ast s w it h t he pr ev ious m odel, in w hich t he PVCs ar e car r ied t r anspar ly acr t heSy net or k . w or ldw ide leader in net w or king f or t he I n t er n et . Autent h ored byoss Cisco stw ems, I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing tFigu echnologies. r e 1 9 -3 Mast . I er n tthe h et erVoATM m s, con cep Sig t s,na t echn li ng ologies, Tr anan sl datdevices e M odel used , tinh teoday ATM ' s net Ne w ork t w ing or k indu . Lear t o incor er net g t echn olog a iesnd in t ATM o a LAN/ env onmvi ent I nt st errypr e t sn thow he Sign alpor in at g ef rint om Bw otorhkin Non -ATM NeWAN t w or kirDe ce. s Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP A sign alin g r equ est fr om an end st at ion causes t he ATM net w or k t o cr eat e an SVC wit h t h e app rop riat e QoS t o t he d esir ed end st at ion. Th e creat ion of an SVC v ersus t he p rior Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age est ablish ment of PVCs is clearly m or e adv ant ageous f or t hr ee r easons: Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . SVCs ar e m or e eff icient user s of b andw idt h t h an PVCs. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing QoS for conn ect ions do n ot n eed t o b e const ant , as w it h PVCs. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu stThe ry . Lear n how t osw incor at ewint er net w or kin g tkechn to a LAN/at WAN env cap abilit y to it chpor calls it hin t he n et w or can olog leadies t o int he elimin ion of t hireonm t andent em. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, PBX an d pot ent ially t he edg e PBX. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

VoATM Reader s w Addressing ill obt ain a g reat er un der st an ding

of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad angds e of intpor egrt al syhstpr em s and serv ices, in clud ing det ailed descr quest ions ATM st anr dar sup b ot ivat e and pub lic addr essing sch em es. Botipt h ion sch s, emrev es iew inv olve tadd o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy resses t hat ar e 2 0 b yt es in lengt h ( show n in Figur e 19 - 4) . For f ur t her inf or mat ion on . Cov eragde ATM is also extessing end edf orm n ot at only o new et wor ing t s,erbut t o old er , legacy st andar addr s, rtefer t o nFigur e k31 - 9 concep in Ch apt 31 also . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir ork.s.ATM Suppor t s a 2 0 -B yt e Addr e ssi ng For m a t Figu r enet 1 9w-4

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The Aut h orit y an d For m at I dent ifier ( AFI ) id en t ifies t he p art icular addr essing f orm at em ploy ed. Thr ee ident if ier s ar e cur rent ly sp ecified: dat a cou nt r y code ( D CC) , in t er n at ional code d esign at or ( I CD) , and E. 16 4. Each is adm inist ered by a st andar ds body . Th e second par t of t he ad dr ess is t he in it ial dom ain id en t ifier ( I DI ) . Th is addr ess uniqu ely id en t if ies t he cust om er' s net w or k . The E. 16u4pdat schem has a of longer DI -tselling hat cor allr espinonds o t he 15d igit I SDN net w ork berage . The The ed eedit ion t he bI est one tnet w ork ing r ef erence p rov idesnum cover of final por t ion, - sp ecific p art ( DSP) , ident ifies logical gr oup ings an d ATM end st at ions. essent ialt he an dd omain cu t t ingedg e t ech nologies. I n a t r anspor t mod el, you don 't need t o be aw ar e of t h e und er ly in g addr esses used by t he voice Con oft rt echn olog essen t o nilit et ywor ing pr lev els, f rom net w or k. cise Howov ev er er,v iew in tsh e anslat e mies odel, t het ial capab t okcom muofession nicat e frals omataall non - ATM nov ice ice t o ex net w or k dev t opert an .ATM n et w or k d ev ice imp lies a lev el of addr ess m apping . Fort unat ely , ATM supp ort s t he E.1 64 add ressin g schem e, wh ich is em ploy ed by t elephon e net w or ks t hr ough out New t he wor ld. chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

VoATM Routing Aut h ored by Cisco Sy st ems, w or ldw ide leader in

net w or king f or t he I n t er n et .

I n t ernuses et w or g Tech nologies Hand , Four t h Ed it ion), , isa ahierar com pr ehensive refer t hat ATM a kprinivat e net w ork - t on et wbook or k int er face ( PNNI chical link - st at e ence r out ing enables w or g p r ofessionals o sag un derst anion d im por ar y int er net w ork pr ot ocol net t h at is kin scalable for globalt u e. I n and ad dit t oplem det eren mtincont ing em reachabilit y an d r out in ing g t echnologies. s, con t s, of t echn w it hin an ATMMast n et werortkhe , itt er is m also capcep able call ologies, set u p. an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com w cuit it h new d urpdat ed chapt er sa on secur it y , wstitor optQoS ical net orem k inent g, scalabilit A v ir plet t ualecir ( VC)ancall eq uest causes conn ect ion h age, cer t ain r eqwuir s t o be y, speed, is gh book a com plet e k. anThe d u pt o-ed at r ef er ence t o wt he hat ined are essen t o ce all rand eq uest ed t ht hrou t heisATM net w or r out t hre ough t h e net or kt op is ics det term by t h et ial sour net w or g pbased rof essionals, ATM swkin it ch on w hatr egar it d etdless er m inofesexispert t heise. b est pat h t hr oug h t he net w or k , based on t h e PNNI pr ot ocol an d t he QoS requ est . Each sw it ch alon g t he pat h is checked t o det er m ine w het h er Reader s wappr ill obt ainiataegrreat un der an ding it h as t he opr esouerrces for stt he conn of ectLAN ion. and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang of int st em ed s and servt rices, clud ing det ailed s, ifrev quest ions When t he conenect ionegr is al estsyablish , v oice af fic in f lows bet w een en ddescr st at ipt ionion s as a iew leased line texist o ened su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . bet w een t he t w o. This specif icat ion spells out rou t ing in p riv at e n et w or k s. Wit hin car r ier Cov e is also t o new n et wor k ing t s,chbut old eren , legacy net werag or ks, t he sw ext it chend - t o-ed swnit ot ch only pr ot ocol is BI CI . Cur r enconcep t r esear analso d d evt oelopm t of syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in w hich int egr at ed non- ATM and ATM r out ing w ill yield new capabilit ies t o b uild t ran slat e- level v oice and pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease ATM net w ork s. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions The B- I CI for is an t h eir in t erf netace w ork bet s. w een t w o d iffer ent public n et w or k p rov ider s or car rier s. I t is t he dem ar cat ion poin t t h at designat es t h e bou ndar y bet w een t h e pu blic car r iers' net w or ks. Th e ph ysical layer of t h e int er face bet w een t h e t w o car rier s is based on t h e CCI TT- d ef ined Net w or k Node I nt er f ace ( NNI ) , w it h t h e addit ion of DS3 and E3 ph ysical lay er s. The B- I CI specif icat ion also includes serv ice- specific f unct ions abov e t he ATM layer t hat ar e r equir ed t o t r anspor t , oper at e, and m anage a v ariet y of int er carr ier ser v ices acr oss t he B- I CI .

VoATM and Delay ATM has sever al m ech anism s f or cont r olling delay and delay var iat ion. The QoS capabilit ies of ATM allow t he specific r equest of const ant - bit - r at e t r aff ic w it h b andw idt h an d d elay v ar iat ion gu aran t ees. Th e use of VC queues allow s each t r aff ic st r eam t o be t reat ed uniq uely . Pr ior it y can be g iven for Table t he t rof ansm ission of voice t r aff ic. The u se of sm all, fix ed- size cells r ed uces queuin g • Content s delay and t h e delay var iat ion associat ed w it h v ariab le- sized p ack et s. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Voice over Frame Relay Voice over Fr am e Relay en ables a net w or k t o car r y live voice t r aff ic ( for ex am ple, t elep hone calls and f axes) ov er a Fr am e Relay net w ork . Fr am e Relay is a com m on an d in ex pensiv e t r anspor t t hat is pr ov ided b y m ost of t he lar g e t elcos. •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

VoFR Signaling By Cisco Systems, Inc.

Hist orically, Fr am e Relay call set u p h as been p r opr iet ar y by vend or. This has meant t hat Pubct lish Ciscod Press pr odu s er: fr om if fer ent v endor s w ou ld n ot int er oper at e. Fr am e Relay For um FRF. 11 est ab lishes a Pub Dat e: Sep tem set ber up 1 1,, 2coding 003 st andar d f or call t y pes, and pack et for m at s f or VoFR, an d it pr ov id es t he b asis f or I SBN: 158 705 -1 19 -2 int er operab ilit y bet w een vend or s. Pages: 11 28

VoFR Addressing Add ress m appin g is h andled t hr oug h st at ic t ab les, d ialed digit s m ap ped t o specif ic PVCs. How The edt ed edit ion of st he - selling ingt or efest erence rov ides cover of ar e v oiceu pdat is r ou depend on bwest hich r out inallg pinr otone ocolnet is w chork osen ablishp PVCs and t h e age har dw essent ial an d cu t t ingedg e t ech nologies. used in t h e Fr am e Relay net w or k . Rout in g can be based on band w idt h lim it s, h ops, delays, or som e com b in at ion, b ut m ost rou t ing imp lem ent at ions are based on m axim izing band w idt h ut ilizat ion. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom ice of t o vex pertand . dat a PVCs is u sed t o m inim ize t he num ber of n et w or k t r ansit hops an d A f ull nov m esh oice t o max im ize t he capab ilit y t o est ablish dif fer en t QoS. A n et w or k designed in t his fashion New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP m inim izes d elay an d im pr ov es voice qu alit y, but it r epr esent s t he hig hest net w or k cost . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Most Fr am e Relay pr ov id er s char g e based on t he num ber of PVCs used . To redu ce cost s, bot h dat a and oice by segm ent sSycan be conf o use t hine net same h ert eby Aut hvored Cisco st ems, w origur ldw ed ide tleader w orPVC, king ft or he I nr educing t er n et . t he num ber of PVCs r equir ed. I n t his d esign , t he cent r al sit e sw it ch r er out es v oice calls. This design has t h e pot entet ialw of ing anologies t ran sit hop hen ,voice o go one rem ot e ofrefer fice ence t o an tot her I n t ern or kcrineat g Tech Handwbook Four needs t h Ed it tion , isfraom com pr ehensive hat renables em ot e office. How ev er , it av oids t h e comp r ession an d d ecom pr ession t hat occu rs wh en u sing net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing a tt and em PBX. echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . A n um ber ofit m can ed m inim izeerdelay and delay varage, iat ion Fr ame n et wor k y, . The Com plet ew h ech newanism an d us pdat chapt s on secur it y , st or opton icala net w or kRelay in g, scalabilit pr esence of long d at a f ram es on a low speed Fr am e Relay lin k can cause u naccept able delays and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o for all tnet im w e-or sensit fr am es. To dless r educe h ispert pr oblem, som e v endor s im plem en t sm aller f r ame kin g ive p rofvoice essionals, r egar of tex ise. sizes t o help redu ce delay and delay var iat ion. FRF. 12 p rop oses an indu st ry - st and ard ap pr oach t o do t his, soobt pr odu fr omerdif enstt an v endor ill beand capWAN able of er koperat and Reader s w ill ain ct a sg reat unfer der ding sofwLAN n etint w or ing, pin argt icu larcon ly t su h em er s w illdw k now hat t y pe ofand v oice y t oolv exp har ar e,wpr ot ocols, ser vqualit ices inv ed ect . Fu. ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Met hod ior it comp izing rveh oice f r ames eren dat a fr am help rresou edu ce d elay anrtdher delay t o en su srefor conprcept en sion andovr et t ion, andesadalso dit ional r ces f or fu st udy . vCov ariat ion . This—and t he use of sm aller fr am e sizes—is v endor specif ic imp lem ent at ion s. To erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy ensur e s, v oice q ualit t he m it t ic ed pict inf or e ( CI R)ldon should beent sets tino w ensur syst em pr ovid in g y,a m orcom e r ealist urmat e of ion t her at realw or n eteach w or kPVC ing en vir onm hiche tpr hat v oice f r ames ar e n ot d iscar ded. Fut u re Fr am e Relay net w or ks will p rov ide SVC signaling of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease f or call setctuivpitand also Fr am e help Relay o r equest a mor QoSefor call. This w -illeffen hance pr odu y anmay d im pr ov eallow eff iciency, ingDTEs t he r teader m ake in taelligent , cost icient VoFR q ualit y in t he f ut ur e. decisions for t h eir net w ork s.

Voice over IP As st at ed pr ev iously, VoI P is an OSI Layer 3 solut ion rat h er t han a Layer 2 solut ion. This feat u re allow s VoI P t o operat e over Fr ame Relay and ATM n et w or k s aut on om ously . More im por t an t ly, VoI P op er at es ov er t yp ical LANs t o go all t he w ay t o t he d esk t op. I n t h is sense, VoI P is m or e of •an applicat ion Table of Content s t han a serv ice, and VoI P pr ot ocols hav e evolv ed w it h t h is in m ind . •

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IVoI nt e P rn p etrot w orocols k ing Te chnologie ndbook th Edit ion cent r alized an d d ist r ibu t ed . I n general t erm s, f all int o t ws oH agener al, Four cat egor ies: cen t r alized m odels follow a client / serv er ar ch it ect u re, w h ile d ist r ibu t ed m odels ar e based on By Cisco Systems, Inc. peer- t o- peer in t eract ions. All VoI P t ech nologies use comm on m edia by t r ansmit t in g v oice inf orm at ion in RTP p ack et s ov er I P. They also agr ee by sup por t ing a w ide var iet y of com p ression Pub lish er: Cisco Press codecs. Th e dif ference lies in sign alin g and w here call log ic and call st at e are main t ained, Pub Dat e: Sep tem ber 1 1, 2 003 w het her at t he end point s or at a cen t ral, in t elligent ser v er. Bot h ar chit ect ur es hav e adv ant ag es I SBN: ant 1- 58 705 -1 19 and disadv ag es. D -2 ist r ibu t ed m odels t end t o scale w ell and ar e m ore r esilient ( r obust ) Pages: 11 28 because t hey lack a cent r al p oin t t hat could f ail. Conv ersely, cent r alized call cont r ol m od els of fer easier m anag em ent and can sup por t t r ad it ion al supp lem ent ar y ser v ices ( such as conf er encing) m or e easily, but t hey can hav e scaling lim it s based on t h e cap acit y of t he cent r al serv er. Hyb rid and int er net w or king m odels being dev elop ed also of fer t he best of bot h app roach es.

Dist ededVoI P ion call of m anagem t schem clu de olding estr ef arerence ch it ect ur e, H. 323cover , andage t h eof The ruibut pdat edit t he b esten - selling all-esin-inone nett he w ork p rov ides new est , Session I nit iat ion Pr ot ocol ( SI P) . Cent ralized call m anag em ent m et h ods includ e Media essent ial an d cu t t ing- edg e t ech nologies. Gat ew ay Con t r ol Pr ot ocol ( MGCP) and p rop riet ar y pr ot ocols, su ch as Sk inn y Clien t Cont r ol Pr ot ocol ( SCCP) and t h e cont r ol pr ot ocol u sed in AVVI D. A br ief over view of each of t hese pr ot ocols is prov over ided Con cise v iewnsexoft . t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant Voice Codec Overview

t opics like VoI P and EAP

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Voice cod er / d ecoder ( codec) t echnolog y has ad van ced r apidly ov er t he p ast few y ear s t hank s t o adv ancem en t s by in DCisco SP arSy chit u r es asldw well researinchnet in w t oorhking um anf orspt eech recognit ion . New Aut h ored stect ems, w or ideas leader he I n and t er n et . codecs do m or e t h an sim ply pr ov ide analog - t o- digit al con ver sion . They can apply soph ist icat ed I n tedict ern etive w or g Tech Edsequ it ionen , ist ly, a com pr ehensive t hat pr p katint ern s t onologies analyze Hand voicebook inpu,t Four an d,t hsub t r ansmit voice urefer singence a min im u m of enables or kin g r ofessionals t o un derst and an im plem ar y int erin net w ork ing ban dw idtnet h. wSome expam ples of voice codecs t hed band widen t h t ucont sed em ar epor discussed t his t echnologies. er voice t he t erismcarr s, con t s, t echn d devices used in t oday ' s net w ork ing sect ion. I n all Mast cases, iedcep in RTP packologies, et s overan I P. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Sim oddulat ed ed ( PCM) v oice is defin TUT G.7 allow t wg, ob asic Comple pletpu e lse w it hcode newman u pdat chapt er s on secured it yby , stIor age, opt11. icalI tnet w orsk in scalabilit y, vand ariat ion s oft h64Kb ps isPCM: Muplet - law and ods ar similar in tthat hat are t heyessen b ot ht ial uset o all speed, is book a com e an d uAp-law t o- .d Th at ee rm efet erhence t o et he t op ics logar it hm pr ession t or egar achieve o 13 b ise. it s of lin ear PCM qualit y in 8 bit s. How ev er, t hey net w or kinic g pcom rof essionals, dless1 2 of t ex pert ar e dif ferent in relat iv ely m inor com pr ession det ails ( Mu- law has a sligh t ad van t age in low - lev el Reader obtrain g reat unce) der. st an ding of hist LANorand WAN n et w orgk coun ing, pt rar icu lar ly ion t h eal signal- tso-wnilloise at ioa perf or er man Usage h as ically been alon y tand r eg har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on bou ndar ies, wit h Nor t h Am er ica using Mu - law and Eu rop e using A- law m odu lat ion . Con ver sion a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions fr om Mu- law t o A- law is t h e r espon sibilit y of t h e Mu- law cou nt r y . When t r oubleshoot ing PCM tsyst o enem sus, re acon cept comp r eh en sion r et ensou t ion, andvad ditbut ionalw ill r esou f orellig fu rtible. her st udy . m ismat ch w ill r esult in and t er r iblending oice st illr ces be int Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Anot h ers,com pr ession mor et ehod oft en useduris ad tapt e diff pulse code m odu ion ( AD PCM) . syst em pr ovid in g a m r ealist ic pict e of he ivrealwerent or ld nial et w or k ing en vir onmlat ent s in w hich A m only used in e. st ance ADPCM, I TU- Tf or G. 726 encodes using 4- bfor it sam ples, givin a pr com of essionals oper at Toolsofand gu id elines opt im izing syst em per m ance w ill incrgease tpr r ansm ratd eim ofpr32 Unlik e help PCM, 4 rbit s do m n ot dirmor ect ly ent elligent cod e t he am p- eff lit uicient de of odu ctission iv it y an ov Kbps. e eff iciency, ingt he t he eader ake e in , cost speech, t hw e ork diffs. erences in amp lit u de as w ell as t he r at e of chang e of t hat am plit ude, decisionsbut forencode t h eir net emp loying som e v er y r ud im ent ar y linear p redict ion. PCM and ADPCM ar e ex amp les of w av ef orm cod ecs, com pr ession t echn iques t h at ex ploit r ed und ant ch aract er ist ics of t h e w avefor m it self. New com pr ession t ech niques h ave b een dev elop ed ov er t he p ast 10 t o 15 year s t hat f ur t her exp loit k now led ge of t h e sou rce

char act er ist ics of sp eech g en er at ion. These t echn iques em ploy sig nal- pr ocessing t ech niqu es t hat com pr ess speech by send in g only sim p lif ied par am et r ic in for m at ion about t he or iginal sp eech excit at ion and v ocal t r act shaping , r eq uir in g less ban dw idt h t o t ran sm it t hat infor m at ion. These t echniqu es can be gr ouped generally as " sou rce" codecs and include var iat ions, such as linear pr edict ive codin g ( LPC) ; code excit ed lin ear p r ed ict ion ( CELP) ; and mu lt ipulse, m ult ilev el qu ant izat ion ( MP- MLQ) . Ther e ar e also subcat egor ies wit h in t h ese codec d ef init ions. For exam ple, code ex cit ed linear • Table of Content s pr edict ion ( CELP) has been aug ment ed by a low - delay ver sion , pr edict ably called LD- CELP ( for • I ndex low - delay CELP) . I t h as also been augm ent ed by a mor e soph ist icat ed v ocal t r act m odeling I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion t echniqu e using conju gat e st r uct ur e algebr aic t r ansf orm at ions. Th is r esult s in a cod ec called By Cisco Systems, CSACELP. The Inc. list goes on and on, but it is im por t an t f or net w or k desig ners t o u nder st and only t he t rad e- off s of t hese appr oaches as t h ey ap ply t o net w ork and applicat ion design . Pub lish er: Cisco Press

AdvPub anced p r ed ict iv e codecs rely on a m at h em at ical m odel of t h e hum an v ocal t r act and, inst ead Dat e: Sep tem ber 1 1, 2 003 of sen ding comp r essed v oice, send m at hem at ical repr esen t at ions so t h at v oice can b e gener at ed I SBN: 1- 58 705 -1 19 -2 at t he r eceiv in g en d. How ever , t his r equ ir ed a gr eat d eal of r esearch t o g et t h e bug s out . For Pages: 11 28 exam ple, som e early p redict iv e codecs d id a good j ob of r epr oducing t h e developer s' v oices and w ere act iv ely pr omot ed —unt il it w as discover ed t h at t h ey did not r epr odu ce female v oices or Asian d ialect s v er y w ell. These cod ecs t h en h ad t o be r edesig ned t o includ e a b road er ran ge of hu man v oice t yp es and sou nds. The IuTU h as andar m- ost p opular coding andar ds for tpelephon and pack et pdat ed st edit ion dized of t het he b est selling all- in-voice one net w orkst ing r ef erence rov idesycover age of vessent oice tial o include f ollow : nologies. an d cu t the ingedg eing t ech G. 71cise 1, wov hich descr ibes t h eolog 64- Kb PCMt ial v oicet echniqu e out lined G. 711 Con er v iew s of t echn iesps essen t o ncoding et wor k ing pr ofession als atearlier. all lev els, f rom encoded is. alr ead y in t h e corr ect f orm at for digit al v oice deliv er y in t h e pu blic phon e nov ice t o voice ex pert net w or k or t h rou gh PBXs. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP G. 72 6, w hich descr ibes ADPCM coding at 40, 32, 24, and 16 Kbps. AD PCM voice m ay also Covinerag be t er chan e of ged cut t ing b et w edge een tpacket echn ologies voice lik and e opt pu blic ical ph n etone woror k ing PBX and netstwor ork age s, pr ov ided t hat t he lat t er has AD PCM cap abilit y. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . G. 72 8, w hich descr ibes a 16- Kb ps, low - delay var iat ion of CELP v oice com pr ession. CELP I n t ernvet w orcodin k in g gTech Hand book it ion ,ony is af orm comat pr ehensive refer hatgh oice m unologies st be t r an scoded t o, aFour pubt hlicEd t eleph for d eliv ery t oence or t htrou enables net w or kin p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t elep hone n etgwor k s. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu stG. ry72 . Lear 9, wnhich howdescr t o incor ibespor CELP at e com int erprnet ession w or kin t hat g t echn enables ologvies oice in t o a beLAN/ coded WAN int env o 8-irKbp onm s ent . Com plet st r eam e w its.h Tw new o van ardiatuions pdat ed of tchapt h is st er ansdar ondsecur ( G. 729 it y , an st d orG.7 age,29opt Annex ical net A) wdiff or kerin g, larg scalabilit ely in y, and speed, com putt hatision book al comp is a lex comit plet y , and e anbot d uhp-g ten o-er d at ally e r pr ef er ovence id e speech t o t he qualit t op icsy t as hatgood are essen as t hat t ialoft o32 allnet w or Kbp kinsgADPCM. p rof essionals, r egar dless of ex pert ise. Reader G.s72 w3. ill 1, obt wain h icha descr g reatibes er unader com st an p ression ding oft echniqu LAN ande WAN t hat can n et wb or e used k ing, fporarcom t icu lar pr essing ly t h e speech har dworarot e,hpr erotaudio ocols,sign andalser com v ices ponent inv olv s ofedmu . Fu lt ndam im ediaent ser alvice t echat nology a v eryinflow or mat bit ion r at e. is pr Asov p ar ided t ofon a b r oad t her ang overeall ofH. int324 egr al f amily sy st em of st s and ard serv s, ices, t his coder in clud ing has det t w oailed bit rdescr at es ipt associat ion s, ed revw iew it h quest it : 5 .ions 3 t o en su and re 6. con 3 cept Kbp s.comp The rhig eh en hersion bit and rat e ris et based en t ion,on and MPadMLQ dit ional t echn r esou ology r ces andf orhas fu rtgrher eat st erudy q ualit . y; Cov erag t heelow is also er b itext r at end e isedbased n ot only on CELP, t o newgives n et wor g ood k ing q ualit concep y , and t s, but pr ovalso idest osyst oldem er , designer legacy s w it h syst em add s, itprion ovid al finlex g ibilit a m or y. e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease As codecs su bject ively com pr m ession t eche niques, st and ard- eff objicient ect iv e pr odu ct iv itryely anincr d imeasing pr ov elyeffon iciency, help ingt ut ned he r eader ake mor in t elligent , cost qu alit y measur su ch as s. t ot al har m onic dist or t ion and sig nal- t o- noise r at ios, hav e less decisions for t hes, eir net w ork corr elat ion wit h per ceiv ed codec q ualit y. A com mon b en ch mar k f or qu ant ify ing t he perf or man ce of t he sp eech cod ec is t he m ean op in ion scor e ( MOS) . Because v oice qualit y an d soun d, in gener al, ar e subj ect iv e t o t he list en er , it is imp ort ant t o get a w ide r ang e of list ener s and sam ple m at erial. MOS t est s ar e giv en t o a g rou p of list eners w ho g ive each sam ple of speech m at er ial a r at ing of 1 ( bad) t o 5 ( ex cellen t ) . Th e scor es ar e t hen aver aged t o g et t he m ean opinion scor e.

MOS t est in g is also used t o com p are h ow w ell a p art icular cod ec w or k s un der var y ing circum st ances, inclu ding dif fer in g backg rou nd noise lev els, mu lt ip le en codes and decodes, and so on . This dat a can t hen be used t o com par e against ot her codecs. MOS scor ing f or sev eral I TU- T cod ecs is illust r at ed in Table 1 9- 1. Th is t able show s t h e r elat ion sh ip b et w een sever al low - bit r at e codecs an d st an dar d PCM. •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Tab le 1 9 - 1 . Re la t iv e Pr ocessin g Com ple xi t y a nd M e an O pin ion Scor es of By Cisco Systems, Inc. Popul ar Voice Code cs Pub lish er: Cisco Press

Bit Ra t e ( Kb ps)

Processing [ 1 ] ( M I PS)

Fra m i ng Si ze MO S Scor e

G. 71 1Pages: PCM11 28

64

0. 34

0. 12 5

4. 1

G. 72 6 AD PCM

32

14

0. 12 5

3. 85

G. 72 8 LD- CELP

16

33

0. 62 5

3. 61

Com p re ssion Dat e: Sep tem ber 1 1, MePub t hod

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G. 72 9 CS- ACELP 8 20 10 3. 92 The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of G. 72 9ial x 2anEn gs edg e8 t ech nologies. 20 10 3. 27 essent d cod cu t in t ingG. 72 9 x 3 En cod in gs

8

20

10

2. 68

ciseACELP ov er v iew s of8 t echn olog ies essen als at all lev G. 72Con 9a CS10t ial .5 t o n et wor k ing pr ofession 10 3.els, 7 f rom nov ice t o ex pert . G. 72 3. 1 MPMLQ 6. 3 16 30 3. 9 New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP G. 72 3. 1 ACELP 5. 3 16 30 3. 65 Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age AutMIh Pored by Cisco Sy given st ems, or ldw ideuments leader54x in net w or king f or t he I n t er n et . pr ocessing power for wTexas I nstr DSPs [ 1]

I n t ern et w in gid Tech Hand Fourpar t h in Edgitvar ionious , is ap com pr ehensive refer ence t hat This t ab leor prkov es in nologies for m at ion usefbook ul in , com opular v oice codec enables netatwion or kin g p r ofessionals t o un plem en tcom contplexit em por intillion er net im plem ent s. The r elat iv e b andw idtderst h as and w ellan asdpim rocessing y (ariny m sw ofork ing t echnologies. Mast er t he[ MI t erPS] m s,) is conu cep t s,int echn ologies, an dt he devices in t odayed 's w net ork ious ing inst r uct ions p er second sef ul un derst and ing t r ad e- used of fs associat it hw var indu st ry I. nLear n how t o incor por at er net wed or kin echn in tcodecs o a LAN/ ir onm codecs. gener al, high er MOS aree int associat w itgh tmor e olog comies plex or WAN m oreenv b andw idtent h. . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

VoIP Network Design Constraints

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e harer Aft dwvar oice e, pr has ot ocols, b een comp and ser ressed v icesand inv olv conv edert . Fu edndam t o dat enta,alt ht ech e nex nology t st epinf isort omat puion t it is intpr o ov a Real ided on a b reoad Tim Pr ot r ang ocole (of RTP) int egr st r eam al sy st f or emt rsansm and ission serv ices, acr oss in clud aning I P det net ailed w or k.descr Net wipt or ion k d s, esigner rev iew sm quest ust ions t o en su rebot consider con h cept ban dw comp idt hr eh and en sion delayand w hen r et en imp t ion, lem and ent ing ad dit VoIional P. Band r esou w idr ces t h requ f or fu irem rt her entst s udy ar e . Covical crit eragan e disar also e d et ext erend m ined ed nnot ot only on ly t by o new t h e ncod et wor ec select k ing concep ed, butt s,also butby also t het oovold er head er , legacy add ed by I P syst em ss,and header pr ovid ot hin erg f a act mor ors.e Ban r ealist dwic idtpict h isurespecially e of t he realcrit ical w or acr ld noss et w ex or kpensiv ing enevir WAN onmlink ent s. s in Delay w hich is pr of aff ect essionals ed by p r oper opagat at e. ionTools delay and ( speed gu id elines of lightf orconst opt im r aint izing s) , syst ser ializat em per ion fordelay m ance( cau w illsed incrby ease pr odu bu ff er ct ing iv itwyitan hind devices im pr ov eineff t ran iciency, sit ) , quan help ting izattion he rdelay eader (m A/ake D codin mor g) e in , an t elligent d p ack, et cost izat- ion eff icient delay . decisions for t h eir net w ork s.

Network Bandwidth Requirements The b andw idt h of a v oice conv ersat ion ov er I P is aff ect ed by a var iet y of fact or s. Fir st , as descr ibed pr eviously , t he cod ec em ploy ed f or t he con ver sat ion can var y w idely f rom as lit t le as 3

t o 4 Kb ps t o as m uch as 64 Kbp s. Lay er 3 ( I P) and Lay er 2 ( Et her net ) headers add addit ional ov er head. Voice p ack et s ar e t y pically ver y small and oft en con t ain no m or e t han 2 0 b yt es of inf orm at ion, so it is ob viou s t hat ov er head can q uick ly ov erw helm t h e ban dw idt h r eq uirem ent s. Sy st em s designer s hav e sever al t ools t o help r educe t h e pr oblem . Fir st , v oice act iv it y d et ect ion ( VAD) is used at t he sou rce t o r eg ulat e t he flow of p ack et s by st op ping t r ansm ission if t h e analog v oice lev el falls below a t hr esh old . This h as t he n et r esu lt of r ed ucing t he b andw idt h r eq uir em ent s b y abou t h alf b ecause m ost h um an con ver sat ion s ar e silent at least h alf t he t im e • Table of Content s as t h e ot her per son t alk s ( u nless t here is a ser ious arg um en t g oin g on …) . •

I ndex

ITher nt e rneetar we or a k ing Te chnologie s H a ndbook Edit ion coup le of pr oblems wit,hFour t h isth solu t ion.

First , sw it ch on/ sw it ch of f t im es m ust be caref By Cisco ully Systems, t un ed tInc. o avoid clip ping. Cisco solv es t his p rob lem by cont inu ously sam p lin g an d cod in g, and t h en dr opp ing t he p ack et at t he last mom ent if voice ener gy fails t o exceed a cer t ain m inim umer:wCisco it hinPress t he allot t ed t im e. I n eff ect , a m ost ly emp t y v oice p ack et is q ueued an d pr ep ared Pub lish for tPub r anspor t , and w ill pr eced e t he speak er ' s fir st u t t eran ce, if necessar y. The ot h er pr oblem Dat e: Sep tem ber 1 1, 2 003 creat ed w it h VAD is t h e lack of n oise at t he receiv er end. Hu m an u ser s of t hese early sy st em s I SBN: 1- 58 705 -1 19 -2 fr equ en t ly com p lain ed t hat it sou nded lik e t h ey h ad been disconnect ed d ur ing t he call because t hey nPages: o long11er28h ear d noise f rom t he ot h er en d w h ile t hey w er e t alk ing. This pr ov es t hat VAD is w or king , bu t is ev ident ly not user- f r ien dly. Cisco and ot h er man ufact u rer s hav e solved t his p rob lem by add ing com for t n oise t o t h e receiv e end of t he conv er sat ion . When a r eceiv er is in bu ff er und er f low con dit ion—t h at is, it is not rThe eceivin g ped ackedit et s—t er at es lowlevnet el w pink or wh e noisep signal convage inceof u pdat ion he of sy t hest bem estg- en selling all-a inone ork ing r efiterence rov idest ocover list en erial s tan h at h ey ar eedg st ille conn ect ed. More adv anced syst em s act ually samp le t he am b ient essent d tcu t t ingt ech nologies. back gr ound n oise at t he f ar end and r epr oduce it dur ing per iods of silence. Anot hCon er tcise ool of ovt en er vused iew s of by tnet echn w or olog k designer ies essens t is ialt ot ocom n et wor pr ess k ing t heprRTP ofession header alss.atAall g reat lev els, dealf rom of inf ormnov at ion ice in t o RTP ex pert h ead . er s is d uplicat ed or redu ndan t in a st r eam. Cisco rou t ers can com pr ess t he RTP h ead er s on a hop- b y- h op basis, r educing r equir ed b andw idt h b y a signif ican t am oun t . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP The end r esu lt of t h ese st eps is illust r at ed in Table 1 9- 2. Th is t able show s t h e r elat iv e ban dw idt h cut t ingcodec edge im t echn ologies lik e opt ical wn it ethwor k ing andover st orhead age associat ed w it h r eq uirCov em erag ent s eofofv ar ious plement at ions, along ad dit ional t y pical net w or k t r anspor t lay ers. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Delay enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Net s p lanning t o imp ent m ust w or kolog w ities hininat o d elay b udg et im posed induwstork ry . design Lear n er how t o incor por at e lem int er netVoI w orPkin g t echn a LAN/ WAN env ir onmby entt he . qu alit y of t he sy st em t o t he user s. As a t yp ical ru le, t ot al endt oen d delay mu st be k ept t o Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilitless y, tand han speed, ab out 1t h50 m s. is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all is book net w or kin g p rof essionals, r egar dless of ex pert ise. Pr opagat ion delay is d et er m in ed b y t he m edium used f or t r ansmission. Th e sp eed of light in a vReader acu ums is 1 86, 0 a miles per secon anding d elect ons and t r avel ab out 00 miles per w ill obt00 ain g reat er un der d, st an of rLAN WAN n et 1w00, or k0ing, p ar t icu larsecon ly t h ed in copper . A net w orand k half arou he. w ld ( 13, 00t ech m iles) w ould t heor ically uce aon har dw ar e, fiber pr ot ocols, serwvay ices invnd olv ted Fuorndam ent0al nology inf or mat et ion is prind ov ided onew ayr delay of int abou Altices, h ough t his ing delay almdescr ost imipt per ibleiew t o quest t he ions a b r oad ang e of egrtal7 0sym stilliseconds. em s and serv in clud detis ailed ioncep s, trev hu earcon , prcept opagcomp at ionr eh d elay s in and conju nct w itand h han delays can cause iceable speech t o man en su re en sion r et enion t ion, addling dit ional r esou r ces f or funot rt her st udy . degr adateion Userext s wend ho ed havn eott alked er sat ellit e kt eleph ony link expalso er ience a derelay Cov erag is .also only t oovnew n et wor ing concep t s, sbut t o old , legacy app 1 secon e cases, w ur it he tof yp tical delaywsorofldab out 2 50 m senbeing t oler le.wDhich elay s systroachin em s, prgovid in g adminorsom e r ealist ic pict he realn et w or k ing vir onm entab s in gr er t han 25 0 matse.b eg in t oand int er e w it h fnoratopt ur alimconv , asmsp eak w ers err up t each pr eat of essionals oper Tools gufer id elines izingersat systion em flow per for ance ill int incr ease ot pr her odu.ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Tab le 1 9 - 2 . VoI P/ Ch a nn el Ba ndw i dt h Con sum pt ion

•

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Hand lin g d elay s can im p act t r adit ional cir cuit - sw it ch ed ph one net w or k s, but t hey ar e a lar ger I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat issu e in p ack et ized env ir onm en t s because of bu ffer ing of pack et s. Th er efor e, delay should be enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing calcu lat ed t o det er m ine w h et h er it st ay s below t he t hr eshold of 15 0 t o 20 0 ms. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . G. 72 9 h as an algor it hm ic delay of about 20 m illisecon ds b ecause of look ahead. I n t y pical VoI P Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, pr odu ct s, t he DSP gener at es a f ram e ev er y 1 0 m illiseconds. Tw o of t hese sp eech fr am es ar e t h en and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all placed w it h in one packet ; t he p ack et d elay , t h er efor e, is 20 m illisecon ds. net w or kin g p rof essionals, r egar dless of ex pert ise. Ther e ar e ot her causes of delay in a pack et - based net w or k: t he t ime necessar y t o m ove t he Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e act ual p acket t o t h e out pu t q ueue, and qu eu e delay. Cisco I OS soft w ar e is q uit e good at m oving har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on and det er min in g t he d est inat ion of a p ack et . ( Th is fact is m ent ion ed because ot her p ack et - based a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions solut ions [ PC- based an d ot hers] are not as good at d et er m ining pack et dest inat ion and m oving t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . t he act u al pack et t o t he ou t put qu eu e. ) The act ual queue d elay of t h e out p ut queue is an ot her Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy cause of delay. This f act or sh ould be k ep t t o less t han 10 m illisecond s w henever p ossible b y syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich using w hat ev er queuing m et hods are opt im al for t hat net w ork . pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it d imt hat pr ovdiff e eff iciency, help mtake mortes in Table 1 93 yshan ows er ent codecs ining t rodt he ucer eader dif fer en am oun oft elligent delay. , cost - eff icient decisions for t h eir net w ork s.

Tab le 1 9 - 3 . Code c- I n t r odu ce d D el ay

Com p re ssion M et h od

Bit Ra t e ( Kb ps)

Com p re ssion D e la y ( m s)

G. 71 1 PCM

64

0. 75

G. 72 6 AD PCM

32

1

G. 72 8 LD- CELP

16

3 to 5

G. 72 9 CS- ACELP

8

10

• G. 72 9a CS- ACELP I ndex

8

10

•

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

G. 72 3. 1 MPMLQ

6. 3

30

G. 72 3. 1 ACELP

5. 3

30

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

I n addit ion 1t o58st705 eady I SBN: -1 19 st -2 at e delay , d iscussed pr ev iou sly , VoI P ap plicat ion s ar e sen sit iv e t o v ariat ion s in t hat d elay . Unlik e cir cuit - based net w ork s, t he en d- t o- end delay ov er a pack et Pages: 11 28 net w or k can v ar y w idely dependin g on net w or k congest ion. Sh ort - t er m v ar iat ions in delay ar e called jit t er , d ef ined as t he v ar iat ion f rom w hen a pack et w as exp ect ed and w hen it act ually is r eceived. Voice d ev ices h ave t o com pensat e f or jit t er b y set t in g u p a play out buf fer t o play back v oice in a sm oot h fashion and t o av oid discont inu it y in t he v oice st r eam . This add s t o t he ov erall syst em d elay ( an d com plexit y ) . Th is r eceiv e b uff er can b e fix ed at some value or, in t h e case of The u pdat ed editCisco ion ofSy t he b est in-apt oneiv net som e adv anced st em s d- selling ev ices, allis ad e. w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Not e t h at j it t er is t he p rim ar y im pedim en t t o t r ansm it t in g VoI P over t h e I nt er net . A t yp ical VoI P call ov er t he I nt er net w ou ld t r av er se m any d if fer ent car r ier sy st em s, w it h w idely var y ing lat en cy Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom and QoS m anagem en t . As a r esult , VoI P over t h e pu blic I n t ern et r esult s in p oor qualit y an d is nov ice t o ex pert . t y pically discour ag ed by VoI P vend ors. Nev er t h eless, man y soft w ar e app licat ions ex ist t o pr ovide fr ee vNew oice chapt ser vices t h e cov I nterag er nete. of The ont opics ch aract er ist icPofand t h ese er s over include imcom por tm ant like VoI EAPVoice ov er I n t ern et syst em s is v er y lar ge r eceiv e buf fer s, w hich can add m or e t han 1 second of delay t o voice calls. Free vCov oice is at r act ivte, t t o bu siness users, t he eans atort age h ese sy st em s ar e erag e tof cut ingbuedge t echn ologies lik e optpoor ical nqualit et wory km ing andt hst w or t hless. How ever , som e r esident ial u ser s ar e f in ding t hem ad eq uat e—esp ecially for b yp assing int er nat ges. Autional h oredt oll bychar Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern t he et f ut I nt ernologies net ser vice prbook ov iders en hance h e , QoS eat ur of t heir refer net wence or ks,t hat Voice wur ore, k inas g Tech Hand , Four t h Ed it tion is a fcom pres ehensive ov er I n t er n et solu t ions w ill becom e m ore p opular . I n fact , m an y analy st s pr ed ict t hat v oice w ill enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing event u ally becom e f r ee, as a bu ndled ser vice w it h I n t ern et access. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Quality of Service for VoIP As seen pr eviou sly , t h e qualit y of v oice is gr eat ly aff ect ed by lat ency and j it t er in a packet net w or k. Theref ore, it is imp or t ant for n et w or k d esigner s t o con sid er im plem en t at ion of QoS policies on t h e net w or k. I n add it ion t o pr ot ect ing voice f rom dat a, t h is has t h e add ed benefit of •pr ot ect ing cr it Table Content ical of dat a appslicat ions f r om ban dw idt h st arv at ion because of over subscrip t ion of •v oice calls. I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

The element s ofInc. good QoS design includ e pr ov isions f or m anag in g packet loss, delay , jit t er , an d By Cisco Systems, ban dw idt h eff iciency. Tools used t o accom plish t hese goals ar e defined her e: Pub lish er: Cisco Press Pub Sep temProv ber 1 ides 1, 2 003 P Dat oli e: ci ng— simp le

lim it ing of pack et r at e, oft en by sim ply d rop ping pack et s t hat exceed I SBN: 1-t58 h resholds 705 -1 19 -2 t o m at ch cap acit ies bet w een dif fer en t n et w or k elem ent s. Policing can b e per for m Pages: 11 ed 28 on eit her inpu t or out pu t of a device. Ex am ples inclu de r and om early d et ect ion ( RED) an d WRED ( w eight ed RED ) . These t ech niques h elp ident if y w hich p ack et s ar e good candid at es t o dr op , if necessar y .

Tra ff ic sha pi ng— Prov ides t h e cap abilit y t o b uf fer and sm oot h t raf fic f low s int o and out of dev ices based on p ack et r at e. Unlik e policin g, h owev er , t raf fic shap ing t r ies t o av oid The udr pdat ion of - selling all- inw ork r efterence rovffides age opped ingedit packet s, tbhe ut bitest t ends t o add latone encynet and j it ting er as hey ar ep bu er edcover for lat er of essentt rial an d cu t t ingedg e t ech nologies. ansm ission. Cal l ad m i ssi on cont r ol— Prov ides t h e cap abilit y t o r eject r equest s f or net w or k band w id t h Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom fr om applicat ions. I n t he case of VoI P, an ex am ple m ig ht be t h e use of Resour ce nov ice t o ex pert . Reser v at ion Prot ocol ( RSVP) t o r eser ve b andw idt h p rior t o com plet ion of a call. Sim ilarly , an H.chapt 323 gat eeper m igh t b ee used naling t o like m anVoI agePaand por EAP t ion of av ailable New er sek include cov erag of imin porsig t ant t opics ban dw idt h on a p er - call basis. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Que ui ng/ sche dul ing — These ar e u sed w it h buf fer in g t o det er m in e t he p r ior it y of p ack et s tAut o be t r ansm t ed. Sy Separ at e qu euldw es ide for leader v oice and datwa, amtple, delaysensit ive h ored by it Cisco st ems, w or in net or for kingexf or he I nallow t er n et . v oice p ack et s t o slip ahead of dat a packet s. Ex am ples useful for VoI P inclu de w eight ed fair inkginand I P RTP pr iorit y queuing , am tong I n t ernqu et eu w or g Tech nologies Hand book , Four h Edot it her ion ,s.is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Ta ggi ng/Mast m aer rk in n clu descep vartious t echn iques tan o ident ify p ack et sinf ort oday special h andling t echnologies. t heg— t erIm s, con s, t echn ologies, d devices used ' s net w ork ing. I n t he case of VoI P pack et s, f or ex amp le, t he pack et s can b e ident ified by RTP for m at ,ent I P. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm pr ecedence b it s ( ToS b it s) , and so on. Tagging is also cr it ical t o p reser v e QoS acr oss Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, net w ortkh is bou ndarisies. For plet ex am ple, swditat ching prence eser vtes P ttagg in gt hat acr oss ATM and speed, book a com e an d ut ag p- t oe r ef er o t Ihe op ics are an essen t ial t o all net w or k, allow ing VoI P t o t r av er se an ATM n et w or k . net w or kin g p rof essionals, r egar dless of ex pert ise. Fra gm at i on— Refers t hst e an capabilit of som net w ork sub div idly e larg Reader sw ill en obtt ain a g reat er unt oder ding ofy LAN ande WAN n et wdevices or k ing,t op ar t icu lar the e int o sm aller ones befor t r av sing a n ent arr ow band wid t h inf link Th is is is crit t o on har dwpack ar e,etprs ot ocols, and ser v ices inveolv eder . Fu ndam al t ech nology or.mat ion prical ov ided pr event oice ackaletsy s fst rom t ing " fr ices, ozen in out " wing hiledet w ait in g descr for a ipt larg a iew packet t o ions go a b r oad r ang ev of intpegr em sget and serv clud ailed iones,dat rev quest t hrre oucon gh.cept Fr agm entrat allows oicead packet s t or esou be inr ser in g aps in. t he t o en su comp ehion en sion andt he r etsm enaller t ion, vand dit ional cest ed f or wfuitrth her st udy lar ger . The lar ge ack ett oisnew sub sequ en kt ly by also a rout ot er ot h er en d Cov erag e is pack also et ext end ed n otponly n et wor ingr eassem concepbled t s, but oldon er ,t he legacy of s,t he lin k in sog t a hat t he a ap is tuhe naff ect ed. syst em pr ovid m or e rdat ealist icplicat pict urion e of realw or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. H.323 Overview H. 323 is a deriv at iv e of t he H. 32 0 v ideoconf er encing st an dar d, b ut it assum es LAN conn ect iv it y r at her t h an I SDN bet w een confer encin g com pon en t s. As such, QoS is not assu m ed and is not im plicit ly sup por t ed. Wh en used t o sup por t a VoI P app licat ion, t he calls are t r eat ed as aud ioonly v ideoconfer en ces.

St and ard s- based v ideocon fer en cing is g en er ally gov ern ed by t he I TU " H- series" r ecom m en dat ions, w h ich include H. 32 0 ( I SD N pr ot ocol) , H. 32 3 ( LAN pr ot ocol) , an d H. 32 4 ( POTS pr ot ocol) . These st andar d s sp ecif y t he m ann er in w hich r eal- t im e aud io, v id eo, and dat a com mu nicat ion s t ak es place over v ar ious com mu nicat ions t op olog ies. St an dar ds com pliance pr om ot es comm on capabilit ies and int er operab ilit y b et ween net w ork ed mu lt im edia building block s t hat m ay be p rov ided by m ult iple v endor s. • s if ied in 19 96 and consist s of t he follow ing com ponent st andar ds: The H. 3 23 st Table an darofd Content w as r at •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

H . 2 2 5 — Specif ies m essag es f or call cont r ol, includin g sign alin g, r egist rat ion and adm ission s, and packet izat ion/ sy nchr onizat ion of m ed ia st r eam s.

By Cisco Systems, Inc.

PubHlish Press ies . 2er: 4 5Cisco — Specif

m essag es f or openin g an d closing channels f or m ed ia st r eam s an d ot her and indicat ions.

Pub com Dat e: man Sepds, tem ber r eq1uest 1, 2 003 s, I SBN: 1- 58 705 -1 19 -2

HPages: . 2 6 111 —28Vid eo codec for audiov isu al ser v ices at P • 64 Kbps. H . 2 6 3 — Specif ies a new v ideo codec f or vid eo POTS. G.7 1 1 — Audio cod ec, 3 .1 k Hz at 48 , 56, and 64 Kbp s ( nor m al t elep hony ) . 2 —edit Audio codt he ec, b7est k Hz at 48,all56, rat rifef ied . The uG.7 pdat2ed ion of - selling in-and one 64 netKbps; w ork ing erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. G.7 2 8 — Audio cod ec, 3 .1 k Hz at 16 Kbp s. G.7 3 —ov Audio cod ec,t echn f or 5.olog 3 and 3 Kbp sm Con 2cise er v iew s of ies 6. essen t ial t oodes. n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . G.7 2 9 — Audio cod ec ( G. 729 a is a redu ced comp lex it y v arian t ) . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Follow ing ar e H. 323 d ev ice descr ipt ions: Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Te in al by — An H. 32 er m inal anide endleader point in on net t hewLAN t hat Autrm h ored Cisco Sy3sttems, w orisldw or king f orprt ov heidI nest erfor n etr .eal- t ime, t w ow ay com mu nicat ions w it h anot her H. 32 3 t er m inal, gat ew ay , or m ult ip oin t cont rol unit . Th is ion consist s of cont r ol, ,indicat ovinpr g ehensive color v ideo p ictence u res,t hat and I n t erncom et w mu or knicat in g Tech nologies Hand book Four t hions, Ed it au iondio, , is amcom refer dat a bet w een t h e t w o t er m in als. A t er minal m ay pr ov id e speech only , speech and dat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w orka, ing speech and v ideo, , dat video. t echnologies. Mast er t heort erspeech m s, con cepa,t s,and t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Gateew witay Anan H.d32 3 gated ewchapt ay ( GW) is an en dpoint t heopt LAN ovkides real- t im Com plet h— new u pdat er s on secur it y , st oron age, icalt hat net pr w or in g, for scalabilit y, e, t w ow ay com mu nicat ions bet w een H. 32 3 t er m inals on t he LAN and ot h er I TU t er m inals and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t oonall a kin W AN, or essionals, t o anot herr egar H. 32dless 3 g at eway . Ot her net w or g p rof of ex pert ise. I TU t erm inals in clud e t hose com ply in g wit h r ecom m en dat ions H. 3 10 ( H. 320 on B- I SDN) , H. 320 ( I SDN) , H. 3 21 ( ATM) , H. 32 2 ( GQOSLAN) , er H. 32 ( man obile) and V.7and 0 ( DSVD) Reader s w,illH.3 obt24 ain( GSTN) a g reat un4M der st ding , of LAN WAN n.et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on P rox y—e The pregr ox yalissyastsp ecial t y pe ofices, g at ew ay t hat in ailed eff ect descr , r elays H.3s,23rev t oiew an ot her ions a b r oad r ang of int em s and serv in clud ing , det ipt ion quest H. re 323con session. Th er eh Cisco pr oxand y isr aetken eyt ion, piece of ad t heditconf er encing infr fast uct ur e st t hudy at can t o en su cept comp en sion and ional r esou r ces or rfu rt her . pr ov QoS, ficedshap policy f ort s, H. 323 t r aff tic. Cov erag e ide is also extt raf end n ot ing, onlyand t o new n etman wor agement k ing concep but also o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Gat e k e epe The gat ek eepgu erid , elines w hich fis in an H.em 32 3per sy for st em , p rovwides callease cont r ol pr of essionals operr— at e. Tools and oropt optional im izing syst m ance ill incr ser v ices t o t he H. 3 23 en dpoint s. Mor e t han one g at ekeeper m ay be p resen t an d t hey pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icientcan com mu w itwhork each decisions for nicat t h eirenet s. ot her in an u nspecif ied f ash ion. The gat ekeeper is logically sep arat e fr om t h e endp oin t s, but it s p hy sical im plement at ion m ay coexist w it h a t er m inal, MCU, g at ew ay , MC, or ot h er non- H. 32 3 LAN d ev ice. Mu lt i poi nt cont r ol uni t — The m ult ipoint cont r ol u nit ( MCU) is an endp oin t on t h e LAN t hat pr ov ides t he capab ilit y for t h r ee or mor e t er m inals and gat ew ay s t o p ar t icipat e in a m ult ipoint conf er ence. I t m ay also connect t w o t erm inals in a point - t o- p oint con ference,

w hich may lat er d ev elop in t o a mu lt ipoint con fer en ce. Th e MCU g en er ally oper at es in t h e fash ion of an H. 231 MCU, b ut an au dio p r ocessor is not man dat or y . The MCU consist s of t w o p ar t s: a m an dat or y m ult ipoint cont r oller an d opt ional m u lt ip oint p r ocessor s. I n t he simp lest case, an MCU m ay consist of only an MC w it h no MPs. Mu lt i poi nt cont r oll er — The m ult ipoint cont r oller ( MC) is an H. 3 23 en t it y on t he LAN t h at pr ov ides for t he cont r ol of t h r ee or mor e t er m inals par t icip at ing in a m ult ipoint conf er ence. I t m ay also conn ect t w o t er m in als in a point - t o- point confer en ce, w h ich m ay lat er dev elop • Table of Content s int o a m ult ipoin t conf er ence. The MC p rov ides f or capabilit y negot iat ion w it h all t erm inals • I ndex t o ach iev e com mon levels of com mu nicat ion s. I t also m ay cont r ol conf erence r esou rces, I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion such as w ho is m u lt icast ing v id eo. The MC does n ot p er f orm mix ing or sw it ch ing of audio, By Cisco Systems, v ideo, andInc. dat a. ntPress p rocessor— PubMu lish lt er:i poi Cisco

The m ult ipoint pr ocessor ( MP) is an H. 323 ent it y on t h e LAN t hat pr ov ides for t he cent r alized pr ocessing of audio, video, an d d at a st r eams in a m ult ipoint Pub Dat e: Sep tem ber 1 1, 2 003 conf er ence. The MP pr ov id es for t h e m ixing , sw it ch in g, or ot her pr ocessing of m ed ia I SBN: 1- 58 705 -1 19 -2 st r eam s u nder t h e con t r ol of t he MC. Th e MP m ay p r ocess a sing le media st r eam or Pages: 11 28 m ult iple m edia st r eams, d ep en ding on t he t yp e of con fer en ce su ppor t ed.

P oint - t o- p oi nt con fe re nce— A poin t - t o- point conf er ence is a conf erence b et w een t w o t er min als. I t m ay be eit her dir ect ly b et ween t w o H. 323 t er m in als or bet w een an H. 323 t er min al and an SCN t er m inal v ia a gat ew ay. I t is a call b et ween t w o t er min als. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of chded t n eettw ornologies. k ( SCN ) — A pu blic or pr iv at e sw it ch ed t elecom m unicat ions essentSw iali tan cu-tcircui t ing- edg ech net w or k such as t he GSTN, N- I SD N, or B- I SDN. H. 323Con pr ov ides fair slyofintt ellig t endp oint s,t ial w hich responsible f or mals aintat aining eir fow n cise ov for er v iew echnen olog ies essen t o n are et wor k ing pr ofession all levt hels, rom call stnov at e.ice I nt o it sexsim plest f orm , H. 32 3 is a peer- t o- peer sig naling sy st em. End point s can call each pert . ot her d irect ly using t he p rocedu res pr ov ided by t he st an dar ds if t h ey k now each ot her 's I P add ress. NewI nit chapt ial call er s include set u p sign covalin erag g emessag of im por es tfollow ant t opics t h e tlike r adit VoI ional P and I SDN EAP Q. 931 m odel, using ASN. 1- f orm at t ed infor m at ion packet s ov er TCP. As such, t h e sig naling pr ot ocol r elies on TCP t ing Aft edge echn ologies e opt ical k ing st or r et ranCov sm erag issione sofforcutQoS. er tt he call set u p lik phase, t he nt et w owor endp oinand t s do a age capab ilit ies exch ange t o negot iat e w hich of sev er al st an dar d audio cod ecs t o use, and, finally , t hey elect RTP por t Sy st ems, w or ldw .ide net w or RTP king por f or tt he I nber t er sn et nu mbAut er shtored o useby f orCisco t he voice m ed ia it self Notleader e t h at in b ecause num ar.e assig ned dy nam ically by t he en dpoint s w it hin a w ide r ang e, t here are som e d if ficult ies oper at ing t hr oug h Ifir n tew ernalls et wunless or k in g tTech nologies book Four h Ed it ion , is hey m aint ain Hand t he call set, up prtocess it self . a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . H.323 Protocol Com plet eCall w it h Flow new anand d u pdat ed chapt erInterworking s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net wpor kin g p rof r egar pert The r ovision ofessionals, t he com mu nicatdless ion isofmex ade inise. t h e st ep s show n in Figur e 19 - 5. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of Figu int egr al in clud detH ailed s, rev iew quest ions r esy1st9em -5s. and Calserv l Fl ices, ow Bet wing e en .3 2descr 3 Deiptviion ces t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing As can be seen f rom Figur e 19 - 5, H. 32 3 is d esign ed t o be r obu st and f lex ible, but at t he cost of t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing less ef ficiency . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

General MGCP Overview Media Gat eway Cont r ol Pr ot ocol ( MGCP) repr esen t s a r elat ively new set of clien t / ser v er VoI P signaling pr ot ocols. These pr ot ocols hav e ev olv ed in answ er t o t h e need f or st at eful, cent r alized m anagem ent of r elat ively du m b end point devices. This capabilit y gr eat ly ext en ds t he ut ilit y of •t he sy st em by Table ofing Content m ak t he sVoI P sy st em easier t o d esign , config ur e, and m anage b ecause all •m ajor sy st emI ndex ch anges occur at t he ser ver . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

At t he t Systems, im e of t his By Cisco Inc. wr it ing , MGCP is an I ETF dr af t . I t m ay n ev er be rat if ied as is b y t he I ETF. I nst ead, a mor e ad van ced der ivat iv e pr ot ocol called MEGACO w ill pr obably b e t he ult imat e solut ion. How ev er , m ar k et dem and has encour aged sev eral vend ors ( inclu ding Cisco Sy st em s) t o Pub lish er: Cisco Press ann ounce sup por t f or MGCP in pr est an dar d for m . This h as cr eat ed t he sit uat ion of a d e fact o Pub Dat e: Sep tem ber 1 1, 2 003 st andar d w it h int erop er abilit y d em onst r at ions am on g v ar ious v endor s. This is g en er ally good f or I SBN: 58 705 -1 19 t he mar k et 1because it-2h as r esult ed in pr oduct s w it h r eal cu st omer v alue f r om v arious vend ors. Pages: 11 28

As w it h m ost st andar ds, MGCP has a color fu l hist or y . I nit ially , a client / ser ver p rot ocol called Sim ple Gat ew ay Con t rol Pr ot ocol w as pr oposed j oint ly by Bellcore ( now Telcord ia) and Cisco Sy st em s. This w as t he fir st st ep t ow ard a t r uly st at eless client . Dur ing t h e sam e p er iod, anot her client / ser ver p rot ocol, called I nt er net Prot ocol D ev ice Cont r ol ( I PD C) , w as b ein g d ev eloped b y Lev 3 in ed conj unct ionof wt he it h bCisco Sy st ems ot her dor PDC w aspcon as aage m ore Theelu pdat edit ion est - selling all- and in- one net vwen ork ings. rIef erence rov ceiv idesed cover of gener ic cont r ol syst em f or v ariou s I P m ult im ed ia dev ices. As t h e t w o p rot ocols m at ur ed in t h e essent ial an d cu t t ing- edg e t ech nologies. st andar d s com m it t ees, t hey ev ent u ally m er ged t o f orm MGCP. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . MGCP Concepts New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP As st at ed befor e, MGCP uses sim p le en dpoint s called media gat ew ays ( MGs) . An int ellig en t m ed iaCov gaterag ew ay cont ( MGC) or call ag enlik t (eCA) ovnides ser v ices. end point pr ov id es user e of cutr oller t ing edge t echn ologies opt pr ical et wor k ing andThe st or age int er act ion s and int er faces, w hile t he MGC p r ovides cent r alized call int ellig en ce. A m ast er / slave r elat ion is pby reser v edSy atstall t imwesorbet eenleader t he MGC and t he MGs. n f act chan ges of st at e Autsh h ip ored Cisco ems, ldwwide in net w or king f or It he I n t,erall n et . ar e for w ar ded t o t h e MGC v ia a ser ies of r elat ively sim p le messages. The MG can t hen ex ecut e I n t ern w or k in Tech nologies t h Ed it ion , is a com pr ehensive refer ence t hat simp leetact ion s gbased on com mHand andsbook f r om, tFour he MGC. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing It echnologies. t is im por t an tMast t o und st at eless u re of t he an MG oin tused s. They e ' ns onet local call er ter hesttand er m ts,h econ cep t s, tnat echn ologies, d endp devices in t hav oday w ork ing int ellig en. ce. ex am inpor t h eatcase of net an wFXS t y gpet echn in t erf aceies su in ppor t ing anWAN analog elep hone, indu st ry LearFor n how t ople, incor e int er or kin olog to a LAN/ envt ir onm ent . w henplet t hee uwser oes an of f-d huook, t he chapt g at eweray notsecur ifies it t he MGC, wh opt ich ical t h ennet inst r uct t h scalabilit e MG t o py,lay Com it h gnew pdat ed s on y , st or age, w or k ins g, tand he dial t on e. W book hen t he eresan digit TMF) a num r elayed o t thoeall speed, t h is is auser coment plet d usp-( D t od at et or efdial er ence t o ber t he, teach op ics dtigit hat is are essen ttial MGC ind ividu allyessionals, becau se tr he MG hasof n oexconcept net w or kin g p rof egar dless pert ise.of a dial plan. I t doesn 't k now w hen t he u ser has dialed enoug h d igit s t o com p let e a call. I n a sense, t he MG b ecom es a logical ex t ension of Reader s wIill obt g reat er un an ding LAN as and WAN et w,ort hey k ing,need p ar tbicu t h eced only t he MGC. f an y ain newa serv ices ar eder in st t rod uced of ( such call w aitning) e lar int ly r odu har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on int o t he MGC. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Ty essagres sentand over P/ UDP een he MGr esou an d rtces h e MGC. Any t o pically en su re, MGCP con ceptm comp eh are en sion r etIen t ion, bet andwad dittional f or fu rt herspecial st udy . tCov eleperag hony sign alinext g in t ered f aces sucht oasnew t h e nDetchan a Primt s, ar but y Rat e I nt f ace) ar e sim ply e is also end n ot (only wor knel ingofconcep also t oerold er , legacy for wem ar ded ectinlyg t a om t he for icp rocessing t h an er m inat ing t h em in onm t h e ent MG.s Th syst s, prdir ovid or MGC e r ealist pict ur e of rtat heher realw ort ld n et w or k ing en vir in is w hich m s t hat f oroper t y pical ions, t helines e dat af or conopt nect betsyst w een h e MG t he MGC cr it ical pr ean of essionals at e. applicat Tools and gu id imion izing em t per for mand ance w ill incris ease tpr o odu keep calls upd. im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient ct iv it y an decisions for t h eir net w ork s. The m edia con nect ion ( v oice pat h) it self is usually ov er I P/ RTP, b ut direct VoATM and VoFr ame Relay can also be used. ( I n fact , MGCP does not specif y t he m edia. ) For secu r it y , MGCP uses I PSec t o p rot ect t he signaling inf orm at ion.

MGCP Advantages MGCP of fer s sev eral adv ant ages ov er t y pical H. 323 im plement at ion s. Alt houg h MGCP has not been r at if ied as an off icial st andar d, en ough v en dor s hav e dem onst r at ed in t er oper abilit y t hat it can be safely deploy ed b y cu st omer s w it hout f ear of b ein g lock ed in. I t lev er ages ex ist ing I ETF pr ot ocols ( SDP, SAP, RTSP) . Pr obab ly m ost imp or t ant ly , t he cent r alized call cont r ol m od el in MGCP allow s for mu ch m or e eff icient ser v ice cr eat ion env iron m en t s, inclu ding billing, call ag en t s, •m essaging serv Table of Content ices, an d sos on. Depend ing on vend or imp lem ent at ion, t he MGC can supp ort •st andar d comI ndex put er t elephon y int egr at ion ( CTI ) int er faces, su ch as Telephon y Applicat ion IPr ntogr e rn et w or k ing H a ndbook Edit ion am min g ITe ntchnologie er f ace ( sTAPI ) used, Four on th PBXs. By Cisco Systems, Inc. Pub lish er: Cisco Press Definitions MGCP Protocol Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: mod 1- 58 705 -1 19 -2 ies t h e follow ing: The MGCP el specif Pages: 11 28

End poin t s— Specif ic t r unk / por t or ser v ice, such as an annou ncem ent ser v er . Conne ct ions— The equiv alen t of a session . Con nect ion s off er sev eral mod es: send , r eceive, send/ r eceiv e, inact ive, loopb ack , an d a cont inu it y t est . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essentCal ial ls— an d Gr cuouping t t ing- edg t ech nologies. s ofe connect ions. Cal l ag en t s— The m edia g at ew ay cont roller ( MGC) . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom ice t o exar pert . MGCPnov m essages e com posed f r om a shor t list of pr imit iv es: New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP N ot i fi ca t i on Re que st ( RQ N T) — I n st ru ct s t he g at ew ay t o w at ch for specific event s. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age N ot i fy ( N TFY) — I n for m s t he MGC w hen r equest ed ev ent s occur . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Cre at e Conne ct ion ( CR CX ) — Cr eat es a connect ion t o an en dpoin t inside t h e gat ew ay . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Mod if yConne ( M DCX )t — Chan ges t heanpdaram et ers w ar it hy an estnet abw lished enables net w or kin g ct p rion ofessionals o un derst and im plem enassociat t cont emedpor int er ork ing connect ion. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Dee le w t eConne Delet an er exist ingsecur connect ion. Ack opt r et ur ns net callw st istg,ics. Com plet it h new ct anion d u— pdat ed es chapt s on it y , st or age, ical orat k in scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Au ditg En poin t ( AU EP) — Audit anexex ist ing net w or kin p rof essionals, r egar dlesssof pert ise. endp oint . Aus dit ( AU — Audit s an of exLAN ist ingand conn ect ion. Reader w illConne obt ainctaion g reat erCX) un der st an ding WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Re st ar t I nP rogr ess ( RSI P) — I s a gat ew ay n ot if icat ion t o t he MGC t hat an MG or an a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions endp oin t is r est art in g or st opping . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Of specif ic int er est are t he n ot ificat ion m essag es. Th e m ed ia gat ew ay uses t hese m essages t o t ell syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich t he MGC of a chan ge of st at e. They t y pically in volv e signaling or ev en t s. Som e ex am ples of each pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease ar e list ed her e: pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Si gna ls— Ringin g, dist inct iv e r in ging ( 0 t o 7 ) , r ingb ack t one, dial t one, int er cept t one, net w or k congest ion t one, busy t on e, con fir m t on e, answer t one, call w ait in g t one, off - hook w ar ning t one, p re- em pt ion t one, cont inu it y t one, cont in uit y t est , DTMF t ones Ev en t s— Fax t ones, mod em t ones, con t inuit y t one, cont inu it y det ect ion ( as a result of a

cont inu it y t est ) , on- hook t r ansit ion , off - hook t ran sit ion , flash hook , r eceipt of D TMF dig it s MGCP h as a n um ber of feat ur es t h at m ak e it at t r act iv e for d ep loym ent of VoI P syst em s. Fir st , m essaging is UDP- based rat her t han TCP- b ased, w hich m ak es it m or e ef ficient . Th e cent ralized cont r ol m odel is sub ject t o a sing le point of failur e, so m ed ia gat ew ay s can b e designed t o r ever t t o a st and by MGC u pon failur e of t he pr imar y cont r oller. This can r esult in t he mod el being as r eliable as any ot h er call cont rol mod el. MGCP scales w ell, t yp ically depend in g only on t he pr ocessing pow er of t he MGC. When t hat becom es t he lim it ing fact or , t h e net w or k can b e • Table of Content s subd ivided int o separ at e MGC dom ains. Ther ef or e, an MGCP call cont rol mod el can scale t o • I ndex m illions of en dpoint s. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

The By Cisco p r ot Systems, ocol is also Inc. r eliable, w it h an ack now ledgm ent for each requ est con sist ing of one of t hr ee opt ion s: success, t r ansien t er ror , an d p er m anent err or . Requ est s t hat are n ot ack now ledged can be rPub et rlish ieder:. MGCP also r elies on DNS t o r esolv e nam es t o I P addr esses. This m eans t hat t he I P Cisco Press addPub ress can be abst r act ed t o m ult iple nod es, or a single n ode can hav e m ult iple I P ad dr esses. Dat e: Sep tem ber 1 1, 2 003 Again, all t his ad ds t o t he f lex ibilit y of t he pr ot ocol. I SBN: 1- 58 705 -1 19 -2

Pages: 11 28 Ty pical MGCP call flow is sh ow n in Figur e 19 - 6.

Figu r e 1 9 -6 . Ty pical M GCP Fl ow The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

General SIP Tutorial Session I n it iat ion Pr ot ocol ( SI P) is a new en t ry in t o t h e sig naling ar en a, w it h a peer - t o- peer ar ch it ect u re mu ch lik e H.3 23. Howev er , unlik e H.3 23, SI P is an I n t ern et - t yp e pr ot ocol in ph ilosoph y and int ent . I t is descr ibed in RFC 2 543 , w hich w as d ev eloped w it h t h e I ETF MMUSI C •Wor k in g Gr oup Table Content s in ofSept em ber 19 99. Many t echnolog ist s regar d SI P as a com p et it or t o H. 32 3 an d •com plem ent ar I ndex y t o client / ser ver pr ot ocols such as MGCP. As such, it w ill pr obably see Ideploy nt e rn etm w or a ndbook Edit ionof com bin at ions of SI P end point s alon g w it h MGCP enkting in Te mchnologie ixed envsirHon ment s, Four comthposed devCisco ices.Systems, Inc. By SI P d ep en ds on r elat iv ely in t elligent endpoin t s, w hich r equir e lit t le or n o int er act ion w it h Pub lish er: Cisco Press ser v ers. Each endp oint man ages it s ow n sig naling, b ot h t o t h e user and t o ot her endp oin t s. Pub Dat e: Sep tem ber 1 1, 2 003 Fund ament ally , t h e SI P pr ot ocol p rov ides session con t rol, wh ile MGCP pr ov id es device cont r ol. I SBN: 1- 58 This p rov ides SI705 P -1 w 19 it h-2a n um ber of adv ant ages. Fir st , t he sim ple m essage st r u ct u re pr ovid es f or call setPages: u p in11f 28 ew er st eps t h an H. 32 3 so t hat per for m ance is bet t er t han H. 32 3 u sin g sim ilar pr ocessing har dw ar e. SI P is also m or e scalable t han H.3 23 because it is inh er ent ly a dist r ib ut ed and st at eless call m odel. Perh aps t h e k ey d iff er ence ( and adv ant ag e) of SI P is t h e fact t hat it is t r uly an I nt er net - m odel pr ot ocol f rom incep t ion. I t uses sim ple ASCI I m essag in g ( in st ead of ASN. 1) based on HTTP/ 1. 1. This m ean s t hat SI P m essagin g is easy t o decod e and tThe r oubu leshoot mor im por ly , it allm ean t hatnet Webpe rap plicat ionp srov can sup por t age SI Pof pdat ed —b editution of et he b estt ant - selling in-sone w orkt ying ef erence ides cover ser v ices w it h m inim al chang es. I n fact , SI P fully sup por t s URL ( w it h D NS) nam ing in addit ion t o essent ial an d cu t t ing- edg e t ech nologies. st andar d E. 16 4 Nort h Am erican Num ber in g Plan add r essing. Th at m eans t h at in a SI P m odel, a user' s e- m ail add ress and ph one add r ess can be t h e sam e. I t also means t hat t he session is abst r act Coned cise so ov t hat er vview er ys diff of terent echn olog endp ies oinessen t s can t ial com to m n et unwor icatkeing w itpr h ofession each ot hals er .at all lev els, f rom nov ice t o ex pert . SI P is m odeled t o supp ort som e or all of f iv e f acet s of est ablishing and t er min at in g mu lt imedia com mu New nicat chapt ion s. er Each s include of t hese cov erag facet e sofcan im por b e tdiscov ant t opics er ed like or n VoI eg otPiat and ed EAP in a SI P session bet w een t w o end point s. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored User locatby ionCisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ernUser et w or capab k in g ilit Tech iesnologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing User av ailabilit t echnologies. Mast ery t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Calle set Com plet w itup h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Call net w or kinhgandling p rof essionals, r egar dless of ex pert ise. Alt hou gh is ain ph ilosoph ically p eer - t op eer ot ocol, is mad upk of logical client Reader s wSI illPobt a g reat er unader st an ding of pr LAN and it WAN n et e w or ing, p ar t icu lar lys tand he ser v ers, of t en collocat ed w it hin an en dpoint . For ex am ple, a t yp ical SI P client m ay anided I P on har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion isbe pr ov ph one, PC, or PDA; it cont ains b ot h a user agent client ( UAC) t o or iginat e SI P requ est s an d aions a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest user agent ser v er ( UAS) t o t er m inat e SI P r equest s. Also supp ort ed ar e SI P pr ox y ser v ers, t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udySI . P rCov ed irect ser ver s ( RS) , regist r ars, an d locat ion ser v er s. Th ese ser v ers are all opt ional, b ut also erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy vsyst er yem v aluable in inact ual SI e P rimp lem atur ions. s, pr ovid g a m or ealist icent pict e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease SI P serv ers are defined here: pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. P rox y se rv e r— Act s as a serv er and clien t ; init iat es SI P r equest s on behalf of a UAC. Re di re ct ser ve r ( RS) — Receives a SI P r eq uest , m aps t h e dest inat ion t o on e or m ore add resses, an d r esp onds w it h t h ose addr esses.

Re gi st r ar — Accept s r equest s f or t he r egist r at ion of a cur rent locat ion f r om UACs. Typ ically is collocat ed w it h a r ed ir ect serv er . Loca t ion ser ve r— Prov ides inf orm at ion abou t a callee's p ossible locat ions, t y pically cont act ed b y a r edir ect ser v er . A locat ion serv er/ ser vice m ay co- ex ist w it h a SI P redir ect ser v er. •

Table of Content s

SIP Messages • I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

SI m essages of a sim ple v ocabular y of r equest s and r esp onses. Req uest s are called By P Cisco Systems,consist Inc. m et hods an d in clu de t h ese: Pub lish er: Cisco Press Pub Dat e: STER— Sep tem berRegist 1 1, 2 003 REGI er s

cur r en t locat ion w it h t h e ser v er .

I SBN: 1- 58 705 -1 19 -2

IPages: N V I TE— 11 28 I s sent by t h e caller t o init iat e a call. ACK— I s sent by t h e caller t o ackn owledg e accept an ce of a call by t h e callee. This m essag e is not r espon ded t o. BY E— I s sent by eit her side t o end a call. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essentCAN ial an d cu tIt singedgt oe end t echanologies. CEL— sent call not yet con nect ed. OP TI ON S— I s sent t o q uer y cap abilit ies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

SIP Addressing New chapt er s include

cov erag e of im por t ant t opics like VoI P and EAP

Covioned erag eprofevcut t ing, edge t echn ologies lik e eled opt ical wor and st or ex age As m ent iously SI P add ressin g is mod aftneretm ailtk oing URLs. For am ple, a t y pical SI P ad dr ess m ight look like: Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. sip: "einstein" [email protected]; transport=udp Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy How ev er , st andar d E. 16 4 ad dr essing can also be supp ort ed by em bedd in g it in t he sam e URL syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich for m at , lik e t his: pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

[email protected]; user=phone

The ad dr ess st r uct u re also in dicat es par amet er s, su ch as t ran sp ort t y pe an d m u lt icast ad dr ess. •

Table of Content s

•

I ndex

SIP Flow I nt e rn Call et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

As seen in Figur e 19 - 7, call set up w it h SI P is mu ch sim pler t han H. 323 , even w it h a pr ox y ser v er inv olved. Wit hout t he pr oxy ser ver , t he en dpoint s m ust k now each ot her . How ev er , call set u p Pub lish er: Cisco Press pr oceeds fr om a sim ple I NVI TE messag e dir ect ly f r om one end point t o t he ot her . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 1 9 -7 . Cal l Fl ow for Se ssion I ni t i at i on Pr ot ocol ( SI P) [ View full size im age]

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Skinny Client Control Protocol (SCCP) SCCP, also r ef er r ed t o as " Sk inny , " is a Cisco Sy st em s p rop riet ar y sig naling and cont r ol p rot ocol used for call est ablish ment , t eard ow n, an d cont rol in VoI P env ir onm ent s. I t is t h e hear t of t h e Cisco AVVI D solut ion . I t is w idely deploy ed in VoI P ent er pr ise solut ion s and is incr easing ly •supp ort ed byTable of par Content s t hir dt y solut ions in serv ice pr ov id er en vir onm ent s. •

I ndex

I nt e rnaetsim w orp k le, ing ligh Te chnologie ndbook Four th Editt hat ion is v er y f eat u r e- r ich d ep loyed in conj un ct ion w it h t is t w eig hts Hstaim ulus , pr ot ocol Cisco I P Ph ones. The signaling pat h u ses TCP por t 200 0, an d t h e m ed ia pat h u ses UDP. Th e By Cisco Systems, Inc. m essage set f or t h e con t r ol of t he client has t hr ee basic ar eas: r eg ist r at ion and m anagem ent , call cont r ol ( set up, t ear d own , and st at ist ics) , an d media ( audio) st ream cont r ol. I t w as init ially Pub lish er: Cisco Press designed and deploy ed w it h Cisco Call Man ager bu t h as sin ce gained m u ch at t ent ion f rom t hir de: Sep tem ber 1 1, 2 003 par tPub y vDat endor s. The Call Man ager or Soft Swit ch cont r ols t he end point s, est ablishm en t , t ear dow n, I SBN: 58 705 19 -2 but t he end point s st r eam m edia d ir ect ly bet w een one an ot her . and account1-ing of -1 calls, Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Comparison and Contrast of the Various VoIP Signaling Alternatives The v ar ious signaling alt er nat iv es each off er adv ant ages an d d isad van t ages for sy st em •designer s. A Table of Content f ew highligh t ss ar e pr esent ed her e. •

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, et r egar ansdH H. 3 23, t, he scope IFirst nt e rn w or k ding ing TeMGCP chnologie a ndbook Four th Editof iont he pr ot ocols is diff er ent . MGCP is a sim ple dev icecont r ol p rot ocol, w hile H. 32 3 is a fu llfeat ur ed m u lt im edia conf erencing pr ot ocol. H. 323 is By Cisco Systems, Inc. cur r en t ly appr ov ed u p t o v er sion 3 , w hile MGCP h as not been an d m ay n ev er be f ully r at ified; it is m erely a d e fact o st andar d adopt ed by som e m anu fact ur ers. As su ch , MGCP int er oper abilit y lish er: Cisco Press hasPub been dem onst r at ed, bu t n ot ind ust r y- w ide. Likew ise, t he com plex it y of H. 323 h as inhibit ed Pub Dat e: Sep 1, 2 003 int er operab ilit ytemasberw1ell. I SBN: 1- 58 705 -1 19 -2

MGCPPages: can set up a call in as f ew as t w o r oun d- t r ips, w hile H. 323 t y pically r eq uires seven or eight 11 28 r ound - t r ips. ( Not e: H. 32 3v 2 p rov ides f or a f ast st ar t p rocess t o set u p som e calls in on ly t w o r ound - t r ips, but t h is is not wid ely im plem en t ed .) Call cont rol is lit t le mor e t h an device cont r ol f or MGCP, w hile H. 323 d er ives call f low fr om Q.9 31 I SDN signaling as a m ed ia cont r ol p rot ocol. Th is cont r ol inf or mat ion is t r ansm it t ed over UDP f or MGCP, and ov er TCP for H. 32 3. The u pdat est -com selling in-Th one r ef- erence SI P an d H.ed 32 edit 3 arion e mof or et he dirbect pet itallors. ey net arewbork ot hing peer t o- p eerp, rov f ull-ides featcover ur ed age mu ltof im edia essent ial an d cu t t ingedg e t ech nologies. pr ot ocols. SI P is an I ETF RFC, wh ile H.3 23v 3 has b een appr ov ed b y t he I TU. I nt er operab ilit y of bot h p rot ocols h as been d em onst r at ed. SI P is mor e eff icient t han H. 32 3, allow ing som e call set ups in cise as litov t leeras a ssinofgle r ound - t ries ip. essen I n addit uses ing I nt ern yp elev prels, ot ocols, Con v iew t echn olog t ialion, t o nSI et P wor k ingexist pr ofession alsetat- tall f rom w hile nov H. 323 cont in ues t o ev olve n ew elem en t s t o fit in t o t h e Q. 93 1 I SDN m odel. ice t o ex pert . Com par ison of SI o MGCPcov is erag sim ilar t he ison like of H.VoI 323 o MGCP, New chapt erPs tinclude e oft oim porcom t antpar t opics P tand EAP in t h at SI P ( lik e H. 323 ) is a m ed ia- con t rol pr ot ocol and MGCP is a device- cont r ol pr ot ocol. The sam e d if fer en ces emer ge befor bettwing eenedge client echn t / ser ologies v er and lik peer t oical peer . The dif fer en ce is t hat Covas erag e ofe cut e opt n et wor kf und ing am andenstt al or age peer- t o- peer pr ot ocols, such as H. 32 3 an d SI P, t en d t o scale m or e gr acefully , bu t clien t / ser v er pr ot ocols, su ch by as Cisco MGCP, easier d esign and minaint Aut h ored Syare st ems, w ort oldw ide leader netain. w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Evolution of Solutions for Voice over Data The f ir st pr odu ct s t o int eg rat e voice and dat a w ere t arg et ed at elim inat ing long- dist ance t elep hone t oll ch ar ges by p rov iding t ie lines bet w een PBXs ov er a W AN inf rast r uct ur e. These pr odu ct s w er e t y pically int egr at ed in t o a rou t er or anot h er dat a device and pr ov ided sim ple •point - t o- point Table Content s t ie of line serv ice using sim ple an alog t ru nk por t s. As t he pr odu ct s m at ur ed, m or e •int er face t y pes I ndex w ere su ppor t ed, in clud ing digit al in t er f aces, E& M, an d ot her t y pes. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Lat er , as capab ilit By Cisco Systems, Inc.ies im pr ov ed , suppor t for analog t elephon e set s w as int r oduced. Th is app licat ion w as init ially t ar get ed at off - pr emises ex t ensions f r om t he PBXs usin g Priv at e Lin e Aut om at ic Rin gdow n ( PLAR) cir cu it s, but lat er DTMF d et ect ion w as added w it hin t hese gat ew ay Pub lish er: Cisco Press dev ices along w it h su ppor t for b asic dial plan s. Ult im at ely , t h is r esult ed in t h e capabilit y of t h e Pub Dat e: Sep tem ber 1 1, 2 003 WAN n et wor k d ev ices t o pr ov ide n ot only t ran sp ort , but also t an dem swit chin g f or t h e at t ached PBXs. I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Ov er t im e, en t er pr ise- wid e call log ic began t o migr at e t ow ard t h e WAN dat a net w or k elem ent s. Each indiv idual PBX at t he edg e of t he WAN clou d n eeded only t o for w ar d in t er sit e calls int o t he WAN g at eway s, w it hou t r egar d for f ur t her d et ailed t ru nk r out e calculat ions. Dial plans pr ov isioned in dat a gat ew ays, such as Cisco Sy st em s- int egr at ed v oice/ r out er s, w hich wer e suf o man t r un kinb gest b -etselling w een allmaniny one sit es.net w ork ing r ef erence p rov ides cover age of Theficient u pdatted edit age ion of t he essent ial an d cu t t ing- edg e t ech nologies. This m odel w or k ed v ery well, esp ecially for sm aller net w ork s of 1 0 or few er sit es. How ev er , as inst allat ions gr ew incr easing ly larg er w it h g reat er nu m bers of sit es, it b ecam e dif ficult t o adm inist erer y vt im sit olog e w as ed tor p lan w as ot herw ise , els, net wf rom or k Coner. ciseEvov iewesaofnew t echn iesadd essen ialt ht oe ndial et wor k ing pr ofession alschang at alled lev engineer s w ould need t o m anually log in t o ever y r out er in t he n et w or k t o m ake cor r espon ding nov ice t o ex pert . dial p lan chan ges. This pr ocess wit h u nw ieldy and er r or - pr one. Ult im at ely , v en dor s began int r odu cin gchapt t oolsertshat mad ecov t his j obe easier. For ex am ple,like t heVoI Cisco Voice Man ager ( CVM) pr odu ct New include erag of im por t ant t opics P and EAP pr ov ides a GUI in t er f ace f or dial plan con figu rat ion and m anag em ent , and allow s n et wor k engineer Covserag to m e an of age cut t hu ingndr edge eds t of echn v oice ologies gat ew likays. e opt ical n et wor k ing and st or age Again,Aut t hese h ored solu byt ions CiscowSy erestsu ems, ff icient w or ldw for ide m any leader applicat in net ions, w orbu king t scalin f or t he g ag I nain t er nbet ecam . e an issue for ev en lar ger sy st em sizes w it h m any hu ndr eds t o t hou san ds of nod es. As lar g e en t er p rises I n t ern et wice or kpr inovid g Tech booke ,t he Four t h Edolog it ion a com pr ehensive refer ence tin hatt wo and serv er snologies b eg an t oHand evaluat t echn y,, tishey discover ed scalin g issues enables net w or kin g p r ofessionals t o un derst an dand im plem t cont por arion. y int er net w ork ing gener al ar eas: connect ion ad mission cont roland ( CAC) dial penlan centem r alizat t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indunect Con st ry ion . Lear adm n how issiont ocont incor r ol por b ecam at e int e er mnet or ewimp or kin ortgant t echn as olog voice iest rin afft oic agrLAN/ ew . WAN I t b ecam env ir e onm obv ious ent . tCom hat plet alt hou e wgh it hanew g at ew anay d ucould pdat ed see chapt anoterher s on g at secur ew ay it yacr , stoss or age, a logopt ical ical f latnet mwesh or kninetg,w scalabilit or k , it w as y, and alw not speed, ays possible t h is bookt oiscom a com pletplet e aecall. an d Au pm et t o-hod d at ew as r ef er needed ence t ofort he som t op e ics centthat r al int areellig essen en ce t ialt ot oact all nettwr af as orfic kincop g p rof and essionals, t o r egulat r egar e t hedless nu mof ber exof pert calls ise.b et w een cr it ical nodes. Calls ex ceeding t he defin ed nu m ber w ould be dr op ped or rer out ed as necessary . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw Dial p lans ar e, also pr ot ocols, becamand e t ooser lar v ices ge t oinv adm olv inist ed . Fu er ndam on sment allaln et t ech wornology k element inf ors.mat Th ion e flat is m presh ov ided on taopolog b r oadyr ang essent e ofially int egr mad alesy it stnem ecessar s andy serv t o stices, ore dial in clud plan inginf det orm ailed at ion descr abou ipttion alls,sitrev es iew in each questnode. ions t o enory Mem su reand conpr cept ocessor complimit r eh en at sion ion s and soonr et b ecam en t ion, e t he andlim aditdit ingional fact or r esou t o frur ces t her f or gr fuow rt her t h. st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy The solut t o bot hese pr oblem sw t het he in trealr oduct ion content r ol.s Iinn w t he syst em s, ion pr ovid in ghaof m tor e r ealist ic pict uras e of w or ld of n etcent w orrkalized ing encall vir onm hich case of Voice ov er at Fram e Relay er opt ATM, v irt u alsyst swem it chper cont oller -tyw peillsy st em s w er e pr of essionals oper e. Tools andan gud idVoice elinesovf or im izing forr m ance incr ease int r odu r alize log ichelp anding int ellig ce. Lik VoI P, t he ,H.cost 3 23- eff gat ekeeper pr odu ctced iv it yt oancent d im pr ov et he effcall iciency, t he ren eader m ew akeise, morf or e in t elligent icient fu nct ion was t o pr ov ids.e t his cent r alized cont r ol f un ct ion . I n t h e case of Cisco Syst em s, for decisions for tused h eir net w ork exam ple, t h e Mult im edia Confer encin g Manager ( MCM) H.3 23 gat ek eeper app licat ion w as deploy ed t o supp ort v oice n et w or k s as w ell as t h e vid eoconf er encing net w or ks for w hich it w as dev elop ed . Not e t h at cent r alized call cont r ol logic d oes not m ean cent ralizat ion of voice p at hs. On ly t he dial

plan adm inist r at ion an d call cont rol are cent r alized. Th e act ual sw it ch ing of voice pack et s st ill occu r s in t h e dat a net w or k elem en t s as it alway s h as, so t he in herent econ om ies an d ef ficiencies of pack et v oice solut ion s rem ain in t act .

The Future: Telephony Applications •As int egr at edTable of Content s t ions cont inu e t o m at u re, a new w av e of app licat ions h as emer ged voice/ dat a solu •fr om var ious I v ndex endor s. I nst ead of p r ovidin g sim ple t r anspor t and sw it ching f unct ions for PBXs, Ipack nt e rnet et w or k ing Te chnologie s Hnaow ndbook , Four Edit ion v oice solut ion s can begin t othreplace

t hose PBXs w it h an end- t o- end solut ion. This m ean s tSystems, hat packInc. et v oice t echn olog ies ar e n o long er a ser v ice pr ovid ed by t he net w or k , but t h ey By Cisco becom e an ap plicat ion r un ning on t he n et w or k . The dist in ct ion is cr it ical in t er m s of how t hese pr odu s er: ar e marPress k et ed an d ad min ist er ed . These pr odu ct s can be cat egor ized by ar chit ect u re and Pubct lish Cisco consist of t he f ollow in g g en er al t yp es: Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 11 28 UPages: n- PBX — I n t h is archit ect ur e, a PC- based serv er cont ains bot h t r unk gat ew ay por t s and analog t elep hone p ort s. Typ ically , special sof t w are and dr iver s r unn in g on an NT operat in g syst em p rov ide all st an dar d k ey syst em f unct ions t o t h e analog t eleph ones. Supp lem ent ar y fu nct ions, such as " hold" an d " t r ansfer " , ar e act iv at ed via hook f la sh an d * com m ands. The sy st em s t yp ically scale u p t o as m any as 48 t elep hones. Not e t hat t h er e is no ed und butoft he cost ofallt he st em less t han hat of older k ey The urpdat ed ancy, edit ion t heover b estall - selling in-sy one netcan w orkbe ingmu r efcherence p rovtides cover age of syst em s. Many p rod uct s includ e int egr at ed v oicem ail b y sav ing dig it ized v oice m essages on essent ial an d cu t t ing- edg e t ech nologies. t he har d d isk .

LA - P BX— a tgechn en er olog al cat egor y oft ial p rod t hat ar eprbased on als LANatt elep hony t he ConNcise ov er This v iew sisof ies essen t o uct n etswor k ing ofession all lev els, all f rom w ayice t o ttoheexdpert esk t.op. Som e p rod uct s of fer LAN t eleph ony ser v ices t h r ough t he use of a nov soft w ar e clien t on t he user ' s PC, w hile ot h er s act u ally of fer t elephon e inst ru m en t s t hat plug int o tchapt he LAN. t h e latcov t ererag , p r oduct s can t he MAC layEAP er ( Et her net ) , ATM, or I P. New er s Of include e of im por t be antbtased opicson like VoI P and Pr oduct s at Lay er 3 ( t hose t h at ar e I P- based) off er g r eat er f lex ibilit y and scaling b ecause I P Cov of cut t ing edge t echn ologies e optpr ical n et k ing or age is a erag rou t e able pr ot ocol. That m ean s t hat lik t hese odu ct swor can b e and usedston dif fer en t LAN seg m en t s. Prod uct s based on low er - lay er pr ot ocols of fer an at t r act iv e p rice poin t because Aut h ored Cisco st ems, client comby plex it y isSy low er. w or ldw ide leader in net w or king f or t he I n t er n et . I n t er ernt et or kginrgunTech nologies book ,esFour t h Ed it ion , is a com preehensive t hat Ov hewlon , the gr eat estHand ch alleng f acing LAN t elephon y ar reliabilit yrefer andence scalab ilit y . enables net w or kin gbe p rad ofessionals un derst plem en t cont em por ar er net w ork ing These issues m ust dr essed ift ov oice/ dat and a int an egrdatim ion is ever t o replace t hye int t r adit ional PBX t echnologies. Mast t eress m s,t hese con cep t s, t echn t oday net w ork ing ar ch it ect u re. Pr oduer ct st he addr issues in a ologies, n um ber an of dw devices ay s. For used ex aminple, t he' sCisco indu st rys. ILear n how yt osolu incor porpat e int er net or und kin gant t echn ies in t og aser LAN/ . Sy st em P t elephon t ion r ovides f or w r ed callolog pr ocessin ver sWAN so t henv at ir if onm one ent f ails, e w itones h newswan d utpdat ed chapt erits. on it y , st or age, opt mod ical net or k in g, scalabilit tCom he Iplet P t eleph it ch o a back up un I n secur ad dit ion, call cont rol els wt hat r edu ce ser very, and plex speed, t h ov is ide book a com plet e an d at e r ef er ence t o Sy t hesttems op icsprt oduct hat are com it y pr f oris bet t er scalab ilitdy .u Ip-n t tohis case, t he Cisco s uessen se a t ial t o all net w or kinver g p rof egar exMGCP, pert ise.called Sk inny St at ion Pr ot ocol. Th is allow s a client / ser callessionals, cont r ol mrod el dless sim ilaroft o single serv er t o man age t h ousands of t elephon e endp oin t s ( t elep hones an d g at ew ay por t s) . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Incentives Toward Packet Telephony Applications t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em LANb ased s, pr tovid eleph in g ony am solut or e ions r ealist officerpict at tur r act e of iv et he bu sin realess w or m odels ld n et w t oorcon k ing su mer en virs onm t od ay. ent sTyp in ical w hich " u npr of essionals PBX" sy st em s oper cost at less e. Tools t han tand h e key gu idsy elines st em sf or t h opt at tim h ey izing r eplace. syst em Likper ew ise, for mLANancebased w ill incr PBX ease pr odu syst emctsivpr it yovan ide d im super pr ov iore eff r eticiency, u r n on inv help esting m ent t het roeader t rad itm ionake al PBX mor esyin sttem elligent s. Alt,hou cost gh - eff init icient ial decisions equipm entforcost t h eir s are netcom w ork par s. able, LAN PBXs t y pically cost mu ch less t o in st all t han PBXs because t hey u se t he exist ing dat a inf rast r uct ur e ( Cat egor y 5 cab lin g) rat h er t han sep arat e voice w ir in g. Adm inist r at ion is also less bu rd en som e b ecause LAN and serv er adm inist r at ors can m anag e t he syst em w it hou t t h e need f or dedicat ed t eleph ony t echnicians. Fin ally , t oll- b yp ass sav ings are also a by pr oduct of t he sy st em b ecause calls bet w een off ices st ay on t h e dat a net w ork fr om end t o en d. Ov er t im e, t hese sav ing s add up t o t he p oin t t h at a LAN- b ased t eleph ony sy st em can

off er consid er ab le sav ings over t r adit ion al PBXs. This is n ot t o say t hat PBX sy st em s w ill disapp ear ov er night . I nst ead , t r adit ional PBX v en dor s ar e act ively m igr at ing t he ex ist in g p r oduct s t o become p acket - enabled. St art in g w it h simp le dat a t r un k car ds t o p rov ide t oll- b yp ass cap abilit y , PBX v en dor s ar e addin g H. 32 3 VoI P car ds t o allow t he PBXs t o m anag e H. 323 client s as w ell. They see t h e PBX ev olv ing int o a v oice ser v er , m uch as t h e LAN PBX v en dor s ar e buildin g f r om t he gr ound up . On ly t im e w ill t ell w hich solu t ion w ill be su perior , bu t on e t hing is clear: Cust om er s w ill hav e m ore ch oices t han ev er . •

Table of Content s

•Perh aps t h e m I ndex ost com pelling r eason t o con sid er I P t eleph ony - t y pe app licat ions is t he f ut u re Iint nt egr e rn et or k ing Te chnologie s Hw a ndbook , Four ther Edit ion year s, atwion of applicat ions it h v oice. Ov t he

a signif ican t am oun t of w or k has g one int o com By Cisco put Systems, er t elephony Inc. in t egr at ion ( CTI ) in t r adit ional PBXs. Th ese sy st em s began t o off er app licat ion pr ogr am m in g in t er f aces, such as Teleph ony API ( TAPI ) , Telephon y Serv ices API ( TSAPI ) , er: and JavPress a Telephon y API ( JTAPI ) . Th is wor k h as r esult ed in ad van ced call cen t er Pub lish Cisco fu nct ions, includin g scr een pops for ag en t s and act ive call rou t ing bet w een call cent er s. Pub Dat e: Sep tem ber 1 1, 2 003 SBN: 1- 58 705 -1 19 -2 How ev Ier , t ech nologist s believ e t h at t h is is only t h e beginn in g. I nt eg rat ed v oice/ dat a applicat ions Pages: 11 28 w ill r ev olut ionize t he w ay people u se t hese sy st ems. For ex amp le, Unif ied Messag ing en ables users t o access v oicem ail, e- m ail, and fax f r om one com m on ser ver , using w hat ev er media t hey choose. A user can ret r iev e v oicem ails on a PC ( as . w av f iles) or , conv ersely, can r et riev e w rit t en m essages f rom a t elep hone ut ilizin g t ex t - t o- speech capab ilit y in t h e sy st em.

Fund t o all is a allr et inhink ingnet abou t t ing h e wr ef ayerence peoplep rov access d u se The uament pdat edal edit iont hese of t heexbam estples - selling one w ork idesan cover age of inf orm at ion. I t w ill becom e possib le for t h e r eceiver of a message t o det er m ine t h e m ed ia r at her essent ial an d cu t t ing- edg e t ech nologies. t han t h e sen der. I n add it ion, int egr at ion w it h in t elligent assist ant - t yp e soft w ar e f rom var ious v en dor s w ill enable user s t o set u p ru les f or m anag em ent of all incomin g calls. I n t h e call cen t er , com plex Con business cise ov er vruiew less (of fort echn ex amp olog le,ies chessen eck in gt ial cr edit t o n et befor wor ke ing accept pr ofession in g n ewals or at ders) all lev canels, be f rom app lied novt oice allt ofor exmpert s of. incomin g com m unicat ions ( v oice, e- m ail, an d so on) u nifor m ly. The f inal r esult w ill be n ot on ly cost sav ings, b ut also increased eff iciency f or or ganizat ions t hat can learn s includey.cov erag e of im por t ant t opics like VoI P and EAP t o levNew er ag echapt t his er t echnolog Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary This chap t er has p rov ided an ov er view of t echnologies and ap plicat ion s of int egr at ed v oice/ dat a net w or kin g. Specific p rot ocol an d archit ect ur al d ef init ions f or Voice over Fr ame Relay , Voice ov er ATM, an d VoI P w er e p rov ided. How ev er , m or e im por t ant ly , em phasis w as placed on t h e r easons •w hy t h ese t echn Tableolog of Content s becom e p rev alen t . These t ech nologies supp ort a r ang e of ies h ave •app licat ions wit I ndex h v ery r eal b usin ess b en ef it s for user s. These benef it s inclu de cost sav in gs f r om Iapp nt e rn et wions, or k ingsuch Te chnologie a ndbook th tEdit licat as t oll sbHyp ass t hr, Four ough ot alionr ep lacem en t of PBXs w it h VoI P t echnology . More im Cisco por t ant ly , new in t eg rat ed app licat ions can benef it f rom packet voice t ech nologies. By Systems, Inc. Along w it h t hese t echn ologies com es t he pr essur e of deciding w hich on e is app rop riat e for Pub lish er: Cisco Press specif ic sit u at ions. The value of var ious solut ions w as r ev iew ed, wit h Voice ov er ATM and Voice tem ber 1 1, 2 003 ov erPub FrDat ame:e Sep Relay show n as m ost app rop riat e for sim ple t oll b yp ass and t andem sw it ching; VoI P I SBN: 158 -1 19en -2 d- t o- end v oice ap plicat ion s t o t he deskt op at t he ex pense of gr eat er pr ov ides suppor705 t for Pages: com plex it y .11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What ar e t he t hr ee main pack et v oice t echn olog ies?

2:

I ndexar e p ack et v oice t echn ologies used t o pr ov id e t oll by pass cost sav ings? How

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

: What ar e By Cisco 3 Systems, Inc. 4:

t he pr im ar y v oice- signaling p rot ocols?

Descr ibe h ow peer - t o- peer voice signaling pr ot ocols ar e dif fer en t f rom client / ser ver p rot ocols.

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information Books •

Table of Content s

•

I ndex

•I nt David , Jonat h an. Voice ov er I P Fund e rn et wson or k ing Te chnologie s H a ndbook , Four th am Editent ion als. I nd ianapolis: Cisco Pr ess, March 200 0. By Cisco Systems, Inc.

• New t on, Harr y . Newt on's Telecom Dict ion ary , New Yor k , Mar ch 2 003 . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

• Dodd, Annab el Z. The Essent ial Guide t o Telecom m u nicat ions , New Yor k , Sept em ber 200 1. I SBN: 1- 58 705 -1 19 -2

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 20. Wireless Technologies Obj e ct i ve s • •

Table of Content s

I nt r odu ce w ir eless concept s and t er m in ology . I ndex

I nt e rn Discuss et w or k ingNonTe chnologie a ndbook , Four th Edit ion Lin e- ofs- HSight ( NLOS) w ir eless. By Cisco Systems, Inc.

I nt r odu ce t he elem ent s of a t ot al w ir eless solut ion. Pub lish er: Cisco Press

I nt r odu ce w ir eless local- area n et wor k s ( WLANs) .

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705b-1 19ef -2it s of using w ireless t echn ologies for com m unicat ion. Discuss t he en Pages: 11 28

Wir eless t ech nologies hav e exist ed in on e for m or an ot her since t he end of t h e 180 0s. The m et hods u sed in t ran smission s, st art in g w it h ar c t r ansm it t ers an d going up t o t he m ost sophist icat ed w ir eless comm un icat ion s syst em s, all hav e one m ain pur pose. They ar e d esigned and bu ilt t o t r ansmit infor m at ion t hr oug h f r ee sp ace u sin g elect r om agn et ic w av es. Many d iver se m et hods ar e u sed t o accom plish t h is, but t hey all shar e and ar e lim it ed by t he sam e law s of The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of ph ysics. essent ial an d cu t t ing- edg e t ech nologies. This chap t er cov er s t he b asics of r adio com m un icat ions, st ar t ing w it h generic t heories and concep t s cise and ov m ov t ot echn t he com on,essen con ttem orar w irkeless em s wals e see t odlev ay.els, Then it Con er ving iewon s of ologmies ial pt o n ety wor ing prsyst ofession at all f rom exam nov inesice in tgr eat er det ail t he most popu lar w ir eless n et w or k t y pe—w ir eless localar ea net w or ks o ex pert . ( WLANs) . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Wireless Concepts The f ollow in g sect ions int r odu ce t he p hy sics behin d r adio com m un icat ion s, t he bu ild ing blocks of a r ad io syst em , and t he main t y pes of w ireless sy st ems com m only used t oday . •The b asic goal Table of Content s un icat ion syst em is t o deliv er inf orm at ion , comm only called of any com m •int elligence inI ndex w ir eless cir cles, f r om sour ce t o dest inat ion. This dat a can b e r ep resent ed b y eit her Ianalog nt e rn et w Te chnologie sH thireless Edit ion com m unicat ion, man y basic ph ysical pr oper t ies wor avk ing ef orm s or digit ala ndbook p ulses., Four In w gov ern t h e t r ansm ission, r ecept ion , and behav ior of t h e elect r omag net ic w aves as t hey ar e By Cisco Systems, Inc. creat ed, pr opagat ed, and ult im at ely receiv ed, com plet e w it h t he int elligence t hey hold. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Radio Fundamentals Du ring d iscussion s w it h peer s ab out t he net w or k in g issues w e see t oday , it is am azing h ow m any t im es discussions com e all t he w ay back t o t he basic phy sics w e all lear ned in school. •Tr ansm issionTable of Content t heory , m odus lat ion t heory , t h e concep t of t r ansm it t ed p ow er , an d r eceiv e •sen sit iv it y app I ndex ly t o ev er y t echnolog y w e w ork wit h t od ay t o on e degr ee or anot h er . Wit h all It echnologies, nt e rn et w or k ing including Te chnologie s Hitaal ndbook , Fourer th lin Edit dig subscrib e,ionopt ical, cab le, d ial, and even sim ple RS- 232 , it 's crit ical t o un derst and t h e concep t s and lim it at ion s inher ent in com mu nicat ion b et ween a By Cisco Systems, Inc. t r ansm it t er and a r eceiv er . Pub lish er: Cisco Press From a learn ing and dev elopm ent per sp ect iv e, perh aps w ir eless is t he b est place t o r eally lear n ber 1f und 1, 2 003 andPub un Dat dere:stSep an tem d t he ament als of com m unicat ions. I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The Components of a Wireless Communication System The sim plest for m of w ir eless syst em consist s of a t r an sm it t er , connect ed t o an ant enna w it h a t r ansm ission lin e, wh ich is " conn ect ed" acr oss t h e air int er face t o an an t en na, w h ich feeds a The u pdat edaedit ion of t he bline. est - selling all-tinnetipt w ion ork ing r efserence rov ides agey,oft he r eceiver v ia t r ansmission Alt h ough hisone descr seem sim plepenou gh, cover in r ealit essent ial an d cu t t ingedg e t ech nologies. t echnology in volv ed in t his sy st em is ver y sophist icat ed and const ant ly ev olvin g. Bu t af t er all is said an d d one, r egar dless of h ow adv anced sy st em s b ecom e, t hey all f ind t heir r oot s in t he b asic r adio sy st em sh ow n in Figur e 20 - 1. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Figu r e 2 0 -1 . W i r el ess Com m u ni cat ion Syst e m

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age full size in im age] Aut h ored by Cisco Sy st ems, w or ldw[ View ide leader net w or king f or t he I n t er n et .

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

The m ain comp onent s of a r adio com m unicat ion sy st em are as follow s:

I nt e l lig en ce sour ce — This is t he in for m at ion t hat is t o b e m odulat ed and t r ansmit t ed across t he w ireless lin k for d eliv ery t o t he receiv ing sit e. I t can b e v oice, dat a, or v ideo and can be analog or d ig it al or iginally. Tra nscei ve r— This is t he " rad io." I t cont ain s t he f un ct ion alit y of a t r ansm it t er ( TX) an d a r eceiver ( RX) . • •

Mod ulaTable t or / of dem odusla t or— The int elligence in it s origin al st at e is com bined wit h t h e Content fr equ enIcy g en er at ed by a local oscillat or. ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Loca l oscil la t or ( LO) — The int elligence and t he local oscillat or fr equency ar e com bined in pr odu ces t h e sum , dif fer en ce, an d t wo or iginals. Thr oug h t h e use of a band pass f ilt er , t h e sum f requ en cy is select ed and coupled t o a t r ansmission line, w h er e it is t t oCisco an Press upconv er t er . Th is result s in a sign al called an int erm ediat e f r eq uency ( I F) . I t is Pubsen lish er: t he oscillat or2 fr equency w it h t he in t elligence m odu lat ed ont o it . Th e LO fr equency is Pub Datlocal e: Sep tem ber 1 1, 003 t yI SBN: pically he -1 r esu 1- 58t 705 19 -2lt of a cr y st al or syn t hesized fr equ en cy t hat is d oubled, t rip led, or qu adr upled in st ages u nt il t h e LO fr equ en cy is achiev ed .

By Cisco a fSystems, ilt er , w hInc. ich

Pages: 11 28

U pcon ve rt er — The t r ansceiv er is connect ed t o t he u pconv er t er or out door unit ( ODU) v ia a t ran sm ission line, m ost of t en a coax ial cable. A var iet y of coaxial cables ar e av ailab le. The cab le select ed is based on t h e operat in g fr eq uencies, p ow er lev els, an d lengt h. Tr ansm ission lin es ar e ex plained lat er . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of rol catble —edg Depending on t he t yp e of ODU an d t ran sceiver , t her e also m ight be a essentCont ial an d cu t inge t ech nologies. cont r ol cable t h at p rov ides com mu nicat ion b et ween t he t w o unit s. You m ight not alw ays see rad io syst em s w her e t he I F an d RF por t ions ar e in sep arat e " box es. " Som e r adio Con erev iew s of t echn ologions ies essen t ial t o als The at all els, tfime rom t o syst cise em s ov hav ph ysical connect t h at conn ectn et dirwor ectklying t o pr anofession an t enna. prlev im ary nov ice t o ex pert . use a separ at e I F u nit an d RF un it is w hen t her e is a lon g d ist an ce bet w een t he int elligence point and t h e ant enn a. The t r an sm ission line pr op er t ies, su ch as at t en uat ion, of an I F New er MHz s include erag of RF im por t antoft opics like ar VoI and EAP signalchapt at 70 compcov ared t o ean sig nal 5 .7 GHz e rPadically d if fer ent . I n a w ir eless design you t r y t o keep t he RF t r ansmission lines t o an absolu t e m inim um lengt h, especially Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age as y ou use high er fr equencies. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . D upl e xe r— The du plexer enables f ull- dup lex w ir eless pat h s using a sing le ant enna syst em for each locat ion . Tw o u niqu e fr equencies, on e for t r ansmit and one f or r eceiv e, ar e I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat com bined, y et t h ey maint ain t h eir u niqu en ess. This is called f requ en cy- d iv ision m ult ip lex ing enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing ( FDM) . A com mon du plexing m et hod is t o use t un ed cavit ies m illed out of a m et al, such as t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing alum inum . The cavit y at t en uat es f requ en cies, act ing as a b and pass f ilt er f or t he indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . fr equ en cies of int er est , y et at t en uat ing all ot h er s g reat ly . I n old v oice rad io syst em s t hat Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, had simp lex t ran sm ission pat hs, t he an t enna w as coupled t o t h e receiv er un t il t he and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all t r ansm it t er w as key ed, causing an RF r elay t o couple t he t r ansm it t er out p ut t o t h e ant enna net w or kin g p rof essionals, r egar dless of ex pert ise. syst em . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Ther e ar e w ireless sy st em s w h ose ar chit ect ur e is not fu ll- d uplex . A sim plex, or half- d uplex , har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on syst em is on e in w h ich comm u nicat ion b et w een b ot h en dpoint s is via t he sam e r adio f r eq uency. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Becau se bot h st at ions t r ansm it on t h e sam e f r eq uency w hen a conv er sat ion is ongoing , each t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . par t y m ust m ake sur e t hat t he ot her p art y has st opp ed , or n eit h er of t hem w ill hear t he Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy conv er sat ion. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease This h as been a sim p le in t r oduct ion t o a w ir eless com m unicat ion sy st em. Of cour se, t h er e ar e pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient m any p er m ut at ion s in t he w ay t hese t echnologies ar e im plem ent ed, but t hey all r ely on t he b asic decisions for t h eir net w ork s. bu ild in g block s. Keep in m ind t hat t he g oal is t o accept dat a or int ellig en ce f r om a sou rce and m odulat e it ont o an I F sig nal, w her e it can ult im at ely b e un con ver t ed t o an RF signal and deliver ed acr oss t he op en air . The m et hod s and ph ysics t hat app ly dur ing t his p rocess ar e ex plained in su bseq uent sect ions, bu t f irst , let ' s t ak e a look at t he elect r om agn et ic sp ect r um .

The Electromagnetic Spectrum Elect r om agnet ic ( EM) spect r u m is a t er m used t o descr ibe t he sum of all for m s of rad iat ion. Th e EM spect ru m r ef ers collect iv ely t o all t h e comp onent s. Radiat ion is ener gy ; it t r avels, t heor et ically , at t he speed of ligh t ; an d it is dispersed as it t r av els. Th er e ar e m any for m s of EM •energ y: Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Visib le lig ht , w h ich comes f r om a lam p in y our house

By Cisco Systems, Inc.

Rad io w aves f r om y our f avor it e r adio st at ion Pub lish er: Cisco Press

Micr owav es,ber used Pub Dat e: Sep tem 1 1, 2in 003point - t o- point

r adio link s and ov ens

I SBN: 1- 58 705 -1 19 -2

I nf rar ed and ult r aviolet ligh t , x - r ays, an d g am ma r ays Pages: 11 28

The EM sp ect r um is f ur t her d ivided int o mor e f init e pieces depending on t he use. The im por t ant t hin g t o r em em ber is t hat m ost of t h e sp ect r um is used b y licen sed users, b e t hey ser v ice pr ov iders, g over nm ent agencies f or such t hings as air t r aff ic cont r ol, or t h e m ilit ar y . The ionedit of ion sp ect is n orallmally t h e net r espon y erence of g overpnm t ag en cies, The allocat u pdat ed ofr um t he bfor estu-se selling in- one w orksibilit ing r ef roven ides cover agesuch of as tessent he Feder al Com m un icat ions Com mission ( FCC) in t he U. S. or t he Can adian RadioTelev ision and ial an d cu t t ing- edg e t ech nologies. Telecom m unicat ions Com m ission ( CRTC) in Can ada. Bot h t h ese ag en cies ar e excellent sour ces of r ef erence m at er ial. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Rad ionov fr equencies ar e. m easur ed in h er t z, w h ich is equiv alen t t o cycles per second . When w e deal ice t o ex pert w it h t he h ig her fr equ en cies in t he EM spect r um , w e t end t o u se w avelen gt h as a measur e. This is com mon opt ical echnologies in we hich 50, t ant 131 0, and like 1 550 nan ometEAP er s ( nm ) are com m on Newinchapt er s tinclude cov erag of im8por t opics VoI P and opt ical w av eleng t hs. The reason for u sin g t h is m easur em en t sy st em is t he m anageabilit y of t h e cut twing nu mbCov er s erag b ein eg of d ealt it h.edge t echn ologies lik e opt ical n et wor k ing and st or age Aut ored Syfst ems, w orinldw idez leader in net w or king f or t he I n t er n et . The f or mhula t o by detCisco erm ine r eq uency hert is I n t ernl et=wcor/ kFin g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing w her e t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, l is t het hwisav elengist ha in m et er es an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all and speed, book com plet net w or kin g p rof essionals, r egar dless of ex pert ise.8 c is t h e speed of light in a v acu um ( 3 . 0 x 10 m et er s per second ) Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e F is t h e fr equency in her t z har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions The ar ea of p art icular in t er est in our d iscussion of w ir eless t echnologies is t h e area of t he EM t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . spect ru m called t he r adio w aves p ort ion . The m aj or allocat ion s in t his por t ion of t he EM Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy spect ru m ar e list ed in Table 2 0- 1. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Tab le 2 0 - 1 . M aj or W ir e le ss All ocat ion s

Fre que ncy Sp ect ru m

Se rv ice

Com m e nt s

AM rad io

53 5 t o 17 05 k Hz

Com m ercial r adio band

Analog t elev ision chann els 2 t o 6 ( VHF)

54 t o 88 MHz

Ov er- t he- air br oadcast t elev ision

88 t o 108 MHz

Com m ercial r adio band

•

Table of Content s

• FM r adio

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Analog t elev ision chann els 7

By Inc. t oCisco 13 (Systems, VHF) Pub lish er: Cisco Press

Analog t elev ision chann els 14 e: Sep tem ber 1 1, 2 003 t o Pub 69 Dat ( UHF) I SBN: 1- 58 705 -1 19 -2

17 4 t o 21 6 MHz These fr equency r ang es hav e been ident if ied by t he FCC as supp ort in g digit al t elevision b y 20 07 47 0 t o 80 6 MHz These fr equency r ang es hav e been ident if ied by t he FCC as supp ort in g digit al t elevision b y 20 07

Pages: 11 28

Cellular

82 5 t o 89 4 MHz Analog POTS

I ndu st rial, scien t ific, and m ed ical ( I SM)

90 2 t o 92 8 MHz Unlicensed; pr opr iet ar y sy st em s

PCSu pdat ed edit ion of t he b est - selling 18 50 t allo 1 990 2Gwwork ir eless The in- one net ing r ef erence p rov ides cover age of MHz essent ial an d cu t t ing- edg e t ech nologies. I SM

2. 4 t o 2. 483 5 Unlicensed; 802 .1 1 an d pr opr iet ar y sy st em s GHz Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t oMu ex ltpert . t Mu lt ichan nel ip oin 2. 1 t o 2. 7 GHz 33 chann els 6 MHz w ide; ear mar k ed f or 3G Dist r ibut ion Serv ice ( MMDS) w ireless New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Unlicensed Nat ion al 5. 15 t o 5. 35 Unlicensed; 802 .1 1 an d pr opr iet ar y sy st em s I nf orm Cov aterag ion Ienfr ofast cutr uct t inguredge e ( U- t echn GHzologies lik e opt ical n et wor k ing and st or age NI I ) Aut h ored by Cisco Sy st ems,5.w72 or5ldw t oide 5. 8leader 25 in net w or king f or t he I n t er n et . GHz I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Local Mult ut ion 27 31. 3and anTw o bplem lock senoft cont f requ enpor cies aling 1.w 3 ork GHz enables netipoint w or kinDist g p rib r ofessionals t o.4unt oderst d im em artyotint er net ing Sy st em ( LMDS) GHz t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu ry . Lear how t o incor por atWe int er net or kin gHigh t echn olog in t o a ical LAN/ WAN env ir onm ent . Freestspace opnt ics b and 60wGHz ban dwies idt h; opt r eplacem ent Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and Freespeed, space t op h ist ics book is a com pletI eR an 765 d unm p- t o- d at eHigh r ef erban ence dwt oidtt he h; opt t op ical ics trhat eplacem are essen ent t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Table 2 0- 1 d escr ibes only a sm all f ract ion of t he EM sp ect r um , b ut it show s y ou t he ar eas in har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on w hich most dat a net w ork ing seen t oday occur s. For m ore in for m at ion about t he r em aining a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions spect ru m allocat ion s, con su lt t h e FCC W eb sit e. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich RF Transmission Theory pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions eirout nettwhe ork You hav e for r eadt hab ws. ir eless sy st em, t he elect r om agnet ic spect r um , and t h e com m on fr equ en cy b ands you w ill likely see in a net w ork ing env iron ment . I t is n ow t im e t o look at t h e t heor y behin d r adio com m un icat ion s.

Electromagnetic Energy

To u nder st and how wir eless com mu nicat ions w or k, you m ust und er st and how elect rom ag net ic energ y is gener at ed an d p r opagat ed t hr oug h f r ee sp ace. Wh en cur r en t p asses t hr oug h a piece of w ire, an elect r ic f ield is cr eat ed, w h ich in t ur n cr eat es a m agn et ic f ield . When t he cur r ent is alt ern at ing, as opposed t o d ir ect , t he elect rom agn et ic field is cr eat ed and collapses at t h e sam e r at e as t h e fr equency of t h e alt er n at ing cu rr ent . The m agn et ic f ield also bu ild s and collap ses at t he sam e r at e as t he elect r ical field. Th is act ion gener at es an elect rom ag net ic w ave, w hich is r• adiat ed fr omTable t he ofw Content ir e, w hich at t h is point can b e called an an t enna. s •

I ndex

The r esult ing elect r omag net ic w av e or pu lse is sinu soidal, so it has t he t h ree char act erist ics of I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion t his w av efor m —am plit ude, p hase, and fr equency . These char act er ist ics r esult f r om t he origin al By Cisco w Systems, signal, h ich is Inc. coupled t o t h e ant enn a af t er bein g generat ed in t he t r ansm it t er. ThePub m lish oster:imCisco p ortPress an t cont ribu t ing fact or s t o t he success or failur e of a w ir eless com mu nicat ion systPub emDat are:e Sep t h ose t hat ex ist bet w een t h e out p ut of t he fin al RF p ow er amp lif ier and t he f r ont end tem ber 1 1, 2 003 of t he receiv er. This is w her e w ireless sy st em s eit her w or k or d on't . The p ieces inv olv ed in t h is I SBN: 1- 58 705 -1 19 -2 RF t ran sm ission ar e t he t ran smission lines, t he ant ennas, an d t he air int er face. Pages: 11 28

Power Measurement The f ir st pieces inv olv ed in t he RF t r ansm ission ar e t he t r ansm ission lin es. Befor e w e d iscuss The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t r ansm ission lin es, y ou need t o un derst and t h e imp or t ance and m easu rem en t of p ow er , b ecause essent ial an d cu t t ing- edg e t ech nologies. it is on e of t he most im p ort an t success f act or s in a comm u nicat ion sy st em . The goal of t h e t r ansm ission lin e is t o f ait hf ully deliver t h e sig nal t o t he an t enna w hile m in imizing pow er loss in t he t ran edium e t rolog ansmission cert ain elect icalallspecif icatf ions, Consmission cise ov ermv iew s of. Th t echn ies essenline t ial mu t o st n etalso wor khav inge pr ofession alsr at lev els, rom such as imp ed ance, pow erh andling capab ilit ies, and loss. Th ese char act erist ics ar e all nov ice t o ex pert . int er relat ed and int erest ing. How ev er, t hey ar e out side t h e scop e of t his int rod uct or y discu ssion. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP I n wir eless com mu nicat ions, pow er nor m ally is exp ressed in wat t s or dBm . Th e r ef erence f or 0 dBm is 1 erag MW.eWit larg rad iot echn t r ansm it t ers,likpeow erical t ypnically m easu inage w at t s, but w it h Cov of hcut t inger edge ologies opt et worisk ing andred st or low er pow er out p ut d ev ices, d Bm is m or e man ageable. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Table 2 0- 2 com par es dBm and w at t s. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Tab le 2er0s -on 2 . secur W a tittys, stan d d Bm Com plet e w it h new an d u pdat ed chapt or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. P ow e r in dBm ( Rel a t iv e t o 1 M W ) P ow e r in W at t s Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k10 ing, 50 dBm 0 Wp ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on dBmr ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr 10 ipt W ion s, rev iew quest ions a40 b r oad t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . 30 dBm 1 W Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k 10 ing0 en vir onm ent s in w hich 20 em dBm MW pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease dBm MW , cost - eff icient pr10 odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in10 t elligent decisions for t h eir net w ork s. 0 dBm 1 MW –1 0 d Bm

10 0 u W

–2 0 d Bm

10 uW

–3 0 d Bm

1 uW

To q uickly d et er m ine r elat iv e v alues w hen wor k ing in d Bm , use t he follow in g calculat ions: I f you h ave a pow er incr ease of 1 dBm , m ult ip ly t he pow er b y 1. 25. I f you h ave a pow er incr ease of 2 dBm , m ult ip ly t he pow er b y 1. 5. • •

Table of Content s ndexa pow er incr ease of 3 dBm , m ult ip ly t he pow er b y 2. I f you hIave

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

This also w or k s in rev er se. For inst ance, a d rop of 3 dBm is a one- half dr op in pow er. By Cisco Systems, Inc. For exam ple, g iv en a pow er level of 2 0 d Bm or 1 00 MW, if t he pow er is increased b y 5 dBm , t he Pubin lish Cisco r esult g er: p ow er Press in w at t s w ou ld b e 100 MW , doub led and t h en m ult iplied by a fact or 1. 5 , w hich Pubs Dat tem 1 1, 00330 0 MW. r esult in e:a Sep pow erberlev el2of I SBN: 1- 58 705 -1 19 -2

At t enuPages: at ion 11 is28t h e loss of sig nal pow er as it passes t hr ough a mediu m, w het her it is t he air , a ph ysical t r ansm ission lin e, or ev en an elect r on ic cir cuit , such as a f ilt er . Ju st as y ou m easur e t h e gain, or t he incr ease in a sig nal, y ou also n eed t o be aw ar e of a loss of pow er , or at t enu at ion . I n fact , you need t o be able t o calculat e t h is in a loss bud get t o en sur e t hat w hen a signal is t r ansm it t ed , it arr iv es at t he receiv ing st at ion wit h enou gh st r eng t h. A receiv er m ust b e sen sit iv e enoug h t o be able t o select t he cor r ect fr eq uency. I f t he r eceiver is in cap able of t his, y ou w ill The u pdat ed edit t hever b est - selling in-Ione w ork r ef erence p roving ides cover of nev er be able t o ion dowof n con t , pr odu cinallg an F annet d, ult im ing at ely, demod ulat y our intage elligence. essent ial an d cu t t ing- edg e t ech nologies.

Transmission Lines Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . The p ur pose of a t ran sm ission line is t o pr ov ide t he phy sical con nect ion bet w een t h e t r ansm it t in g s include cov erag e of por t ant P and EAP dev iceNew an dchapt t he rer eceivin g d ev ice. Tran smim ission linest opics com elike in vVoI ar ious f orm s an d mat er ials. I n w ireless net w ork s, t he com m on t y pes ar e Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Coax ial cables I n t ernWav et w or in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat egkuides enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast t he tof er m s, con cepregar t s, t echn devices ' sain net w ork ing Ther e ar e m any v erersions each, b ut dlessologies, of t he t an y ped ch osen, used here in aret oday t he m indu st ryer. ist Lear howneed t o incor porawar at e int er: net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . char act icsn you t o be e of Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all RFkin atgt en uatessionals, ion net w or p rof r egar dless of ex pert ise. I ms pedance Reader w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on DC rloss ar ealalso it t oserv pr ov ide DC p ower t o an upconv ) s, rev iew quest ions a b r oad ang e( ifofyou int egr sy stusing em s and ices, in clud ing det ailed descrer iptt er ion t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Phyesical ch aract er ist eighnt etan d bken rad iu s t s, but also t o old er , legacy Cov erag is also ext end edics, n otsuch only as t o wnew wor ingd concep syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Cost pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu anchar d imact pr ov ake moralso e in tr elligent icient The f irctstivtithry ee er eisteff icsiciency, ar e all help relating ed tt he o a rdeader eg r eeman d are elat ed t,ocost t he- eff fr eq uencies decisions for t h eir net w ork s. t hat ar e t r ansm it t ed on t he w ir e. The higher t h e fr equency , t h e gr eat er t he at t enu at ion, an d, t her efor e, t he g reat er t h e loss. I m pedance is cr it ical, b ecause it mu st m at ch t he dev ices at eit h er en d. An im pedance m ismat ch m ean s t hat t her e is a less- t han- p er f ect t r ansfer of energ y at t he m ech anical connect ion p oint s. Anot h er pr oblem t hat im pedance m ism at ches com poun d is reflect ions. When 10 0% of t he

t r ansm it t ed ener gy is n ot coup led int o t he sink , or d est inat ion circuit , t he ener gy needs t o go som ew her e. This ener gy is eit her r adiat ed in t o f r ee space, w hich is called a leak, or it is r eflect ed t o t he t r ansm it t ing dev ice. This ener gy can cause m any pr oblem s if it is r eflect ed out of phase w it h t he orig in al. An origin al signal t hat is su bject ed t o a reflect ion of it self t hat is eq ual in am plit ude and 180 d eg rees out of ph ase ef fect ively is r ed uced t o 0. I t is inconceiv able t h at a r ef lect ion of 100 % of t h e pow er, 180 degr ees out of phase, w ould ev er occu r, but som e percent ag e of ref lect ion and, t o som e degr ee, • Table of Content s being out of phase w it h t he orig in al alw ays occur s. The result can be addit iv e per fect ly in p hase, • I ndex bu t it is su bt r act ive if n ot . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

I n Cisco By wir eless Systems, t h ese Inc. eff ect s are m easur ed an d ar e called Volt age St anding Wav e Rat io ( VSWR) . VSWR is a m easur e of imp ed ance m ism at ch bet w een t he t ran sm ission line an d it s load , w hich is t he Pub antlish enna. ThePress hig her t he VSWR, t he gr eat er t he m ism at ch. er: Cisco Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Antennas Pages: 11 28

The second piece of t he RF t ran sm ission is t h e gr oup of ant enn as. We hav e discussed t he basic t r ansceiv er and connect ed a t r ansmission line t o it . Now w e need t o look at t h e ot her end of t h e t r ansm ission lin e. This is w her e t he an t enna fit s. The ant enna has t w o m ain f unct ions. One is t o accept RF p ow er fr om t h e t r ansmit t er an d rad iat e it in t he r igh t d ir ect ion, t o t he r eceiv ing The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of ant enn a. The second fu nct ion is t o r eceive t he ener gy f rom t he t r ansm it t er and couple it t o t he essent ial an d cu t t ing- edg e t ech nologies. r eceiver . Ant enn a t h eor y h as sev eral key concept s, as d iscussed nex t . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

Full-Duplex nov ice t oSimultaneous ex pert . Transmission er s include cov erag of t im t ant like and EAP t ran sm ission . Som e On e tNew hing chapt t h at shou ld be ment ion ede is h epor idea of tfopics ull- dup lexVoI simPult aneous r adio sy st em s of fer f ull- dup lex , f ull- t im e t r ansmission. To do t his fr om t he per sp ect iv e of an Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age ant enn a, y ou need t w o u niqu e ant enn as, or a d ev ice t hat can p rov ide a sig nal p at h for t h e t r ansm it hand e fr equencies anide eouleader sly u sin on w e or ant ennfa. Aut oredr eceiv by Cisco Sy st ems, sim w orult ldw ingnet king or This t he Idnev t erice n etis. called a du plex er . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat A d uplexnet er essen act s as a split er derst / com and bin erant hat t wt ocont uniq uepor f requ t owsh e enables w or kint ially g p r ofessionals t o tun d imallow plemsen em ar y en intcies er net orkaring one an t enna. The t r ansm it and r eceiv e fr equencies need t o be r elat ively close t oget her, becau se t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing tindu hey st r ely on t he RF ch aract er ist ics of one liv e ant enn a elem ent . This use of a dup lex er is called ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . fr equplet en cy d iv u ltdiplex inged( FDM) Com ew it hision newman u pdat chapt. er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Man y year s ago, I w as r espon sib le for a m icr ow ave rad io- relay syst em t h at u sed quad r uplexer s. net w or kin g p rof essionals, r egar dless of ex pert ise. This let u s use on e ant enna w it h t w o t r ansm it an d t w o r eceiv e f r eq uencies. The quad ru plex er w as f ix ed, m eaning w eercouldn unding e it , of andLAN it was u red of mpilled alum Reader s w ill obt ain at hgat reat un der'tsttan and man WANufnact et w or k ing, ar t icu lar lyinum t h e. Th e elect r ical behav ior w as t hat of a t u ned cav it y , act ing sim ilar t o a w av eg uide, allow in g t heided desired har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov on signals t o pass w hile at t enu at ing all ot her s. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . An isot r op ic ant enna is a t h eor et ical ant enn a t h at can rad iat e in all dir ect ions equ ally . I t is used Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy as a benchm ar k or r ef erence w hen w e exp ress t he pr opert ies of d ir ect ional ant en nas. When w e syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich evalu at e ant enn as, we ref er t o an ant enn a's g ain , w hich is oft en m easur ed in dBi—t he pow er pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease r adiat ed or r eceiv ed wit h r esp ect t o an isot r opic ant enn a. This p rov ides a st an dar d ref er ence pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient m easu rem en t t h at let s u s com p are ant ennas. Figur e 20 - 2 illust r at es ant enn a t h eor y . decisions for t h eir net w ork s.

Figu r e 2 0 -2 . Ant en na Th eor y

•

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Effective Radiated Power (EIRP) Pages:Isotropic 11 28 Ef fect ive I sot r opic Rad iat ed Pow er ( EI RP) is t h e result of t he RF pow er deliv er ed t o t he an t en na m ult iplied b y t he g ain as ref er enced t o an isot r opic r adiat or . EI RP can b e calculat ed as f ollow s: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essentEIial d cu t t inge t ech+nologies. RPan( dBW) = Ptedg x ( dBW) Gant ( dBi) – Lt lc ( d B) w her e Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Pt x is t h e t r ansm it t er ' s pow er out p ut in d BW New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Gan t is t h e ant enn a gain , t y pically along t h e ant enn a's m ain lobe Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Lt lc is t he loss of t he t ran sm ission line, includin g conn ect or s Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . EI RP is nor m ally calculat ed and r ep ort ed in dBW, b ut can also be calculat ed in dBm and sim p le Iwnat t ern t s. et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast heRP t erinmds,Bm con Here' s an ex am ple er of tEI : cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w( dBm it h new s on– secur y , st or age, opt ical net w or k in g, scalabilit y, EI RP ) = an Pt xd (udpdat Bm)ed + chapt Gant er ( dB) Lt lc ( it dB) and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net wexam For or kinple, g p rof sup essionals, pose a t r ansm r egar it dless t er out of pex utpert s 8 .5 ise. w at t s wit h an 11 dB gain ant enn a, t he cab le loss is 1. 2 dB, and con nect or losses ar e 0. 25 dB. The t r ansm it t er out p ut mu st fir st b e conv er t ed fr om Reader ill obt a RP g reat w at t s t os w dBm . Thain e EI is er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad EI RP r ang = e 3 9. of29 intdBm egr al+sy11. st em 0 dB s and – 1 .serv 45 dB ices, = in 48. clud 8 4 ing d Bmdet EIailed RP descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Antenna Types pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Ther e ar e m any t y pes of ant en nas. Which t yp e y ou choose is d irect ly r elat ed t o t h e t y pe of decisions for t h eir net w ork s. r adiat ion pat t er n, f r eq uency, and RF char act er ist ics of t he w ir eless net w or k cov er age. I t is in select ing an ant enna w here t he concept of EI RP n eeds t o be ev aluat ed, becau se it is a cr it ical fact or in an t en na select ion. Man y t yp es of ant ennas are available f or w ireless sy st em s. Th e m ost basic crit er ion f or dif fer en t iat ion is t h e concep t of d ir ect ionalit y. I n t h is respect , t her e ar e t w o b asic an t enna t yp es:

Om nid ir ect ion al Unidir ect ional An om nidir ect ional ant enna is one in w hich t he t r ansm it t ed p ow er is rad iat ed in all dir ect ion s. A un id irect ional an t enna rad iat es it s en er gy in a sp ecif ic direct ion. •

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Befor e w e pr Ioceed , w e should qu alif y t he p hr ase " in all dir ect ions. " Wh en w e d escrib e an • ndex ant enn a, w e also need t o consider anot h er ant enna t r ait —polar izat ion. An ant enn a's polarizat ion I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion is t he act iv e elem ent ' s ph ysical placem ent r elat iv e t o t he Ear t h . The act iv e elem ent is t he By Inc. antCisco enn aSystems, elem ent t o w h ich t he pow er is applied and, t heref ore, r adiat ed fr om . Ant enn as can be hor izont ally or v er t ically polar ized. Th e diff er ence bet w een an isot r opic and an om nidir ect ional Pub lish ant enn a er: is tCisco h at tPress h e om nidir ect ional ant enn a r adiat es in 360 degr ees, b ut t he r adiat ion pat t er n is limitPub ed Dat bye:t he polar Sep tem ber izat 1 1, 2ion 003 of t he act ive elem en t . I SBN: 1- 58 705 -1 19 -2

An ant enn a's p hy sical com ponent s in clu de an act ive element or element s, r eflect ors, an d Pages: 11 28 dir ect or s. Th e act iv e elem ent is t he element t o w hich ener gy is app lied and r eceived. This elem ent is cou pled t o t he t ran sceiver t h rou gh a t ran sm ission line. A u nidir ect ion al ant enn a dir ect s it s r adiat ed ener gy in a specific d ir ect ion, hence, concent r at ing it . Th is is done t hr ough t h e use of r ef lect or s. Com m on t yp es of unidir ect ion al ant enn as ar e Theabolic, u pdat ed edit ion t hed bish, est -panel, sellingand all- yinoneThnet orkeing r ef h erence p rov idesbe cover par sem ipar abof olic, agi. ey whav a hig g ain an d can ver yage of essent ial al. an They d cu t tar ingedg e ftor ech nologies. dir ect ion e used poin t - t o- point and poin t - t o- m ult ipoint link s. Wit h car efu l engineer in g t hey can b e dir ect ional t o a degr ee, meanin g t h at t h ey can be used in a sect or lay out . For inst ance, in a m obile w ir eless or poin t - t o- m ult ipoint br oadb and deploy ment , a h ub Con ov er veriew echn t ial ee t o nant et wor k ingt hprus ofession als levrad els,iat f rom t r ansm it t cise er / r eceiv sitseof m tay u seolog t hries ee essen 120 - degr ennas, concent r atat ingallt he ed nov ice t o ex pert . energ y in t he desired sect or ( see Figur e 20 - 3) . I n t hese t hr ee sect or s, y ou also n eed t o en su re t hat y ou ef fect ively r eu se t he av ailab le fr equencies ef ficient ly. Consider t h at t h is par t icu lar ar ea New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP of cover age is b ord er ed by ident ical ar eas of cover age. Becau se of t he possibilit y of int er ference bet w een cells if t h ey use sim ilar fr equ en cy p lans, y ou n eed t o ensu re t hat t he f requ en cy plan Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age pr event s int ercell f requ en cy ov er lap ping . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat 0 -3 . Antt oen Sect s—Th r ee 2 0porDareg r ee enables net wFigu or kin gr ep r2 ofessionals unna derst and or an d im plem en t by cont1em y int er s net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

An imp ort ant con cept in t he select ion and perf or man ce of a un idirect ional con e ( or dish) ant enn a is beam w idt h . The en er gy t hat is t ran sm it t ed is concen t r at ed by vir t ue of t he const r uct ion of t he cone t h at p rov ides t he ref lect or f unct ion. A gr eat an alogy for t his is t h e Maglit e st y le of flashligh t . Wh en y ou r ot at e t he lens collar on t his k ind of flashlight , y ou act u ally m ov e t he lig ht bu lb in and out . When you do so, t he wid t h of t he beam of ligh t n arr ow s or w idens. Th e same hap pens w it hTable en erofg yContent pr opagat ed f rom a dish ant enna. The act ual lev el of t r ansm it t ed ener gy ( in • s t his case, light ) r em ains con st an t , bu t is d isp er sed ov er a g reat er ar ea. Ther ef ore, less energ y is • I ndex av ailab le acr oss a gr eat ar ea at t he r eceivin g end . I f you concent r at e t h e beam, you can use I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion low er pow er or per haps reach far t her . By Cisco Systems, Inc.

Figur e 20 - 4 sh ows one t y pe of d ir ect ional an t en na. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 2 0 -4 . Com mon D ir e ct i ona l An t e nn a

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Figur e 20 - 5 sh ows a com mon f orm of omn idir ect ional ant enna. You u se an om n id irect ional ant enn as w w ill hen y ain ou waan t t o er r adiat e tst heant ding ran smit t ed sig nalWAN f r omn et t he base st at ion orlar t ran Reader obt g reat un der of LAN and w or k ing, p ar t icu ly tsm h eit t er sit edw t o ar alle,possib le locat ions a 360 pat t er n.ent Comm onnology syst eminf s in w h ich har pr ot ocols, and serinv ices inv- degr olv edee . Fu ndam al t ech or mat iont his is prisovdesir idedable on arber br oadcast adio andalnav igat Ev serv en wices, it h an id irect t enna, y ou ust inions a oad r ang e rof int egr sy st emion. s and in omn clud ing detional ailed an descr ipt ion s, m rev iewk eep quest t hat as soon as you leave t heand antren y ou and w ill ad notdit ach iev er esou a p err ces f ectf or cir cular cover age tmo ind en su re con cept comp r eh en sion et na, en t ion, ional fu rt her st udy . pat terag er n. eThis is because of nt he an t enna' s r adiat ionkpat n, as tw asalso t h e tenv ir on t hat t he Cov is also ext end ed ot only t o new n et wor ingt er concep s,ell but o old er ,ment legacy signal ravprerovid ses ining fraee space. syst emts, m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figu r e 2 0 -5 . Com mon O m n idi r ect ion al Ant e n na

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28ab out sev er al k ey ant enn a concep t s. You m ig ht hav e not iced t h at w e k eep You hav e r ead m en t ioning ant enn as' t ran sm it ch aract er ist ics. Of cour se, an an t enna m ust also b e able t o r eceive sign als r adiat ed f r om ot her sour ces. Th e sig nals r eceived by an an t en na an d t hat are subsequent ly deliv ered t o t he r eceiver 's fr ont en d ar e in t he mag nit ud e of m icr ov olt s and, in som e sy st ems, ev en low er. I n or der t o effect iv ely p rov ide a su r viv able com mu nicat ion p at h in w ireless com union icatof ions, enn a m ust par t icular ualit ies.p rov These alit ies The u pdat ed m edit t het bhe estant - selling allin-possess one net w ork ing r efqerence idesqu cover ageletoft h e ant ennial a ran eceiv e tex t r emely eaknologies. sig nals and t r ansm it t hem t o t he r eceiver at a lev el st r ong essent d cu t ingedg e twech enoug h t o r ecov er t he m od ulat ed inf or mat ion .

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Free Space RF Propagation

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP The t hir d p iece of RF t ran sm ission is t h e air int er face, or t he fr ee sp ace bet w een t he t r ansm it t ing and r eceivin g eanoft enna sy st em. tAft er ologies t h e en erlik ge y opt leavical es tnhe t r anksm ant enna, it is r adiat ed wit h Cov erag cut t ing edge echn et wor ingit and st or age suf ficient pow er t o reach t he r eceiv in g ant enna, and w it h suf ficien t st r engt h f or t he receiv er. Aut by irCisco Sy st ems, w or ldwgy idepasses leadert hr in oug net w f orely t hehost I n t er n et . n eed t o b e How ev er h, ored t he env onm ent t hat t he ener h or is king ex t r em ile. You aw ar e of m any f act or s an d t ake t hem int o accoun t w hen desig ning a wir eless sy st em . Her e are I n t ern et wt hese or k in fact g Tech som e of or s:nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing space loss t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . indu stFree ry . Lear n how Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Lin e oft hsig and speed, is ht book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Fresnel zon e Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e t h pr buotlgocols, e har dwEar ar e, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions When r adio w av es depar t t he t r ansm it t ing ant enn a, t hey ar e af fect ed by t he at m ospher e, t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ph ysical st r uct ur es, an d geogr aphy as t hey pr opag at e t o t he r eceivin g an t enna. Th e fir st Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy est im at ion y ou m ak e w hen t r ying t o und er st and a pat h is fr ee space loss ( FSL) . This is a best syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich case calculat ion of t he loss incur r ed in a t ran sm ission pat h. I t is t heoret ical and assum es t hat pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease t her e is no dif fr act ion , r ef r act ion , obst r uct ions, or scat t er in g. I t is ju st t he loss in a p at h as a pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient signal pr opagat es f art her fr om t h e sour ce and sp r ead s becau se of beam div er g en ce. I t can be decisions for t h eir net w ork s. calcu lat ed using t his for m ula: Lp = 36. 6 + 20 LogF + 2 0Log D w her e

Lp is t h e fr ee space loss or at t enuat ion bet w een an t en nas in dB The con st an t 3 6. 6 is t he use of st at u t e m iles. I f you u se n aut ical m iles, t h e const ant is 37. 8. F is t h e t r ansm it fr equ en cy in MHz D is t he p at h leng t h in st at u t e m iles •

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Man y FSL calcu lat ors are available on t h e WWW. You can just plug in you r v alu es t o ar r ive at t he • I ndex answ er. Use any sear ch eng in e t o look for " f r ee space loss calcu lat or. " I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

A vCisco By er y imp Systems, ort ant Inc. at t rib ut e in t he b eh avior of rad io w aves is line of sigh t ( LOS) . Line of sit e w it h r adio f r eq uencies is m or e t h an t he abilit y t o see t h e r eceiving an t en na f r om t he t ran sm it t in g ant enn a.er: ToCisco havPress e t r ue LOS, no object s, includin g t r ees, houses, and t he Eart h, can be in t he Pub lish Fresnel zon e. Th e Fresnel zone is t he ar ea ar oun d t he v isu al line of sight t hat r adio w av es Pub Dat e: Sep tem ber 1 1, 2 003 pr opag at e int o aft er t h ey leav e t he t ran sm it t ing an t en na. Th is area mu st be clear , or t he sig nal's I SBN: 1- 58 705 -1 19 -2 qu alit y dim in ish es, b ecause ex t ra at t enuat ion is p resen t . Pages: 11 28

Fresnel zon es ar e zon es of rad iat ed energ y. I n t h eor y , t h er e ar e an inf in it e num b er of t hem. I n pr act ice, h ow ev er, w e con cer n our selv es w it h on ly t he f irst Fr esn el zone. These zones ar e ellip soid in sh ape and ex ist arou nd t he d irect LOS p at h. Th e energ y as it rad iat es f r om t he ant enn a look s like a foot ball. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Iessent n t he ial f ir st zone, need m ost of t h e en er gy t hat is pr esent t o r each t h e r eceiving anFr d esn cu t el t ingedg yeou t ech nologies. ant enn a, not w it h st an ding t h e fr ee sp ace loss y ou exp ect based on t he fr eq uency and dist ance. For t he max im um ener gy t o be conv eyed, you st r ive t o ensur e t hat no m ore t han 40% of t he LOS tCon hr oucise gh tov heerzon v iew e sis of obst t echn r uctolog ed. ies Youessen also tneed ial t o tno et t ak wor e kint ing o accou pr ofession nt t heals Ear att hall 's lev b ulge, els, w f rom hich is a result nov ice of t tohe exEar pertt h. 's cur v at ur e. The com pou nd ef fect of t h ese t w o pat h at t r ibut es d ict at es t he ant enn a's m inim um height abov e gr oun d. Figur e 20 - 6 illust r at es t he ef fect of t h e Ear t h' s bu lg e, chapt e of im por t ant t opics like VoI P and EAP and t hNew e con cepterofs tinclude he Fr esncov el erag zone. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

Figu r e 2 0 -6 . Fr esne l Zone a n d Ea r t h Bu lge

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

To calculat e t h e r adius of t h e fir st Fr esnel zon e, use t his f or mu la: Rf t = 7 2. 1 * t h e squar e of D1 * D2 / FD

w her e Rf t is t he r adius of t he fir st Fr esn el zone in feet D1 is t h e dist ance fr om t he t r ansm it t er t o t h e pat h obst acle D2 is t h e dist ance fr om t he pat h ob st acle t o t he r eceiv er •

Table of Content s

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ndex F is t h e I fr equency in GHz

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

D Systems, is D1 + D2 By Cisco Inc.,

t he dist ance in m iles

To calculat e t h e ef fect of Eart h b ulge, use t h is for m ula: Pub lish er: Cisco Press Datlge:eSep ber=1 1, Ear tPub h bu in tem feet D 22 003 / 8 I SBN: 1- 58 705 -1 19 -2

w her ePages:

11 28

D 2 is t he dist ance b et w een an t ennas squ ar ed Table 2 0- 3 sh ows st an dar d values f or com mon d ist an ces. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn t ial et wor ofession als at all lev els, f rom Tabolog le 2ies 0 -essen 3 . Ea r t tho nBu lg ek ing Valprue s nov ice t o ex pert . D ist New a ncechapt in M er il es Bul gelike i n VoI Fe et s include cov erag e of im por t ant t opics P and EAP 2

0. 5 Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age 4 2. 0 Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . 6 4. 5 I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat 8 8. im 0 plem en t cont em por ar y int er net w ork ing enables net w or kin g p r ofessionals t o un derst and an d t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, 10 12 .5 an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . 12 plet e w it h new an d u pdat ed chapt er s on secur it18 Com y ,.0st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all 14 24 .5 net w or kin g p rof essionals, r egar dless of ex pert ise. 16 32 .0 Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions To ensu re con t hatcept a par t icular r adio h can p er f orm satad isfact or ily,r esou you m ustf or en su reher t hat t he . t o en su re comp r eh en sionpat and r et en t ion, and dit ional r ces fu rt st udy Fresnel zon e is adequat ely clear of obst r uct ions and t h at t h e Ear t h bulg e is allow ed for . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacyTh is m ight havin ing y our an t ennas o thigh er elev ennena vir m onm ast s.ent You also need syst emm s,ean pr ovid g at omraise or e r ealist ic pict ur e tof he realw oratldions n et on w orant k ing s in w hich tpr o of und er st and t he area' s geogr aphy . A good pat h p rof ile and su r vey ar e necessar y t o ensur e essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease t h at w ireless ems perf as iciency, ant icipathelp ed. ing t he r eader m ake mor e in t elligent , cost - eff icient pr odu ct ivsy it yst an d im pr or ovm e eff decisions for t h eir net w ork s.

NLOS Wireless: Overcoming Multipath Signals in NLOS High Speed This sect ion int rod uces one of t he biggest challenges in w ireless com m unicat ions. Modulat ion •m et hods, encoding Table of m Content s an d mit ig at ion t echniq ues also ar e discu ssed. et hods, •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Multipath Signals By Cisco Systems, Inc.

er:hCisco A mPub u ltlish ip at signPress al is t h e com p osit ion of a p rim ar y signal plus d uplicat e or ech oed im ages caused Dat ions e: Sepof temsignals ber 1 1, 2 of 003f obj ect s b et w een t he t r ansm it t er and r eceiver . I n Figur e 20 - 7, t h e by rPub eflect r eceiver h ear s t705 h e-1pr19im I SBN: 1- 58 -2 ary sign al sen t d ir ect ly fr om t h e t r ansm ission facilit y , b ut it also sees secondPages: ar y sig nals t hat ar e bou nced of f n ear b y obj ect s. 11 28

Figu r e 2 0 -7 . M u lt ipa t h Sign al Rece pt ion The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. [ View full size im age]

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w nced ill obtsignals ain a g reat er un an ding andt hWAN n eten wtorsign k ing, ar t icu lar of ly tt h These bou ar r ive at der t h estreceiv er of latLAN er t han e incid al. pBecause he is har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided m isalign ment , t he ou t - of- phase signals w ill cause int er sym bol int erf erence or d ist or t ion of t heon a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions r eceived sig nal. Alt hou gh m ost of t he mu lt ip at h sig nals ar e caused by boun ces of f t all obj ect s, tmo ult enipat su reh con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . signals can also occu r fr om b ounces of f low object s, such as lakes and p avem en t . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst in g asig mnal or eisr ealist ic pict e of ldnal n etan w or ing en onm ent s in w hich The em acts, u alprrovid eceived a comb inatur ion of taheprrealim arwy or sig d ksever al vir echoed sign als. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Becau se t he dist ance t r av eled by t he or iginal sign al is shor t er t han t he boun ced sig nal, t h e t ime pr ct iv it ycauses an d imt pr e eff iciency, ing r eader m akeovmor e inand t elligent costint - eff icient difodu fer en t ial woovsignals t o be rhelp eceiv edt.he These sig nals er lap comb, ine o a sing le decisions for t h eir net w ork s. one. I n r eal lif e, t he t im e b et w een t he fir st r eceiv ed signal and t he last echoed sig nal is called t he delay sp read. I t can be as h ig h as 4 µsec. I n Figur e 20 - 8, t h e ech oed signal is delay ed in t im e an d r educed in p ower . Bot h ar e caused b y t he addit ional dist ance t hat t he bounced sig nal t r av els ov er t h e pr imar y sign al. The gr eat er t he dist ance, t he lon ger t he delay and t he low er t he pow er of t he echoed sign al. You mig ht t hink

t hat t he lon ger t he delay , t he bet t er of f t he r ecept ion w ould be. How ever , if t he delay is t oo long , t he recep t ion of t he ech oed sy mb ol ( S1) and t h e pr imar y sy m bol ( S2 ) can also int eract . Because t her e m ight not be a dir ect pat h for t he incident sig nal in non - lin e- of- sight ( NLOS) env iron ment s, t he pr im ar y sig nal m igh t be sm all in comp ar ison t o ot her second ary sign als.

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re Table of Content Figu s

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I ndex

2 0 -8 . M u lt ipa t h Rece pt i on

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n analog sy st em s, such as t elev ision , t he hum an eye can act ually see t his m ult ipat h signals sit uat ion. Somet im es you see a gh ost im age on y our t elevision, an d n o m at t er how m uch y ou I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat adj ust t he set , t he im age does not go aw ay . I n analog syst em s, t his is an ann oyan ce. I n digit al enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing syst em s, it usu ally cor r upt s t he dat a st r eam and cau ses loss of dat a or low er per for m ance. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Cor r ect ion algor it hm s m ust be pu t int o place t o com p en sat e for t h e m ult ipat h signals, r esu lt in g indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . in a low er available d at a r at e. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all I n digit al sy st em s, t he in put signal is sam pled at t h e sym bol r at e. The echoed sign al act ually net w or kin g p rof essionals, r egar dless of ex pert ise. int er fer es wit h t h e r ecept ion of t he secon d sy m bol, causing int er sy m bol in t er f er ence ( I SI ) . This I SI is t he main r esu lt of m ult ipat h signals. Dig it al syst em s m ust be desig ned t o deal w it h it . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept Microwave Communication comp r eh en sion andLinks r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst emt he s, pr ovid in ggaofmdoreveelopm r ealisten ic tpict uricrow e of tav heerealw or ldt rnansmission et w or k ing en viriponm Since beginnin of m w ir eless equ m enent t , s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr easeed m anuf act ur ers an d operat or s h ave t ried t o m it igat e t he eff ect s of reflect ed signals associat pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost w it h sig nal pr op agat ion. Th ese r eflect ion s ar e called m ult ipat h sig nals. I n real- w or ldeff siticient uat ions, decisions for t h eir net w ork s. m icr ow av e syst em s inv olv e car ef ul design t o ov er come t he eff ect s of mu lt ip at h sig nals. Most m ult ipat h signal mit ig at ion ap pr oach es fall w ell shor t of t he fu ll r eliable in for m at ion r at e pot ent ial of man y w ireless com m un icat ions sy st em s. Th is sect ion discusses how t o cr eat e a digit al m icr ow ave t ran smission sy st em t hat n ot on ly can t oler at e m ult ipat h signals b ut t hat also can act u ally t ake ad van t age of t h em .

Digit al micr ow ave sy st em s f all int o t w o cat egor ies: w avelen gt h s less t h an 1 0 GHz an d w av elengt hs gr eat er t han 10 GHz ( called m illim et er w av es) . Sev er al b ands ex ist below 1 0 GHz for high - sp eed t r ansm issions. These m ay be licen sed ban ds, such as MMDS ( 2. 5 GHz) , or un licensed b ands, such as U- NI I ( 5. 7 GHz) . Band s t hat ar e below 10 GHz hav e long pr opag at ion dist ances ( up t o 30 m iles) . They ar e only m ildly af fect ed b y clim at ic chang es, such as r ain. Th ese fr equ en cies ar e gener ally not ab sor b ed by object s in t he env ir onm en t . They t end t o boun d and, t hu s, r esult in a high nu m ber of m ult ipat h sig nals. •

Table of Content s

Band s over 1 0 GHz, such as 24 GHz, LMDS ( 28 GHz) , an d 3 8 GHz, ar e v er y lim it ed t o dist ance • I ndex ( less t han 5 miles) . They ar e also qu it e su scept ible t o signal fades at t r ibu t ed t o r ain. Mu lt ip at h I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion signals t end not t o be an issu e becau se t he t r ansm ission dist ances ar e less and b ecause m ost of By Systems, Inc. t heCisco mu lt ipat h sig nal ener gy is ab sor bed by t h e ph ysical env ir onm ent . Howev er , wh en t h ese fr equ en cies ar e used in hig hly dense ur ban ar eas, t he sign als t en d t o bou nce off ob ject s, su ch as m etPub al lish bu er: ild in gs Press or m et al w ind ow f ram es. The u se of r epeat ers can ad d t o t he mu lt ip at h sig nal Cisco pr opag at ion b y delayin t he r eceived sig nal. Pub Dat e: Sep tem ber 1 1, g 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Multipath Signals in NLOS Environments I n LOS en vir onm ent s, m ult ipat h signals are u su ally min or and can b e ov er com e easily . The am plit ud es of t he ech oed signals ar e m uch sm aller t h an t h e pr im ary one and can be eff ect iv ely filt ou ed t using st and ion allt ech ever NLOS en vir onm s, tage h e ech Theerued pdat edit ion of ard t he bequalizat est - selling in-niqu onees. netHow w ork ing ,r in ef erence p rov ides ent cover of oed signals m igh t hav e h ig her pow er levels because t he pr im ar y signal m ig ht be par t ially or t ot ally essent ial an d cu t t ing- edg e t ech nologies. obst r uct ed and, g en er ally , because m ore mu lt ip at h sig nals ar e pr esent . This m ak es t he equalizat ion desig n m or e d if ficult . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom I n all nov t heice p rev discussion s, mu lt ipat h sig nals hav e b een a semif ixed ev ent . How ev er , ot h er t oious ex pert . fact or s, such as m oving ob ject s, com e int o play . The par t icu lar m ult ipat h signals cond it ion er ssam include erag of im por ant tis opics liket im VoI P and EAP changNew es fr chapt om one ple pcov er iod t oet he nex t . tThis called e var iat ion . D ig it al syst em s m ust be cap able of w it hst andin g f ast chan ges in m u lt ip at h sign al condit ion s, refer r ed t o as fast fad ing . Covwerag ofcondit cut t ing edge e opt et wor st or To d eal it h t ehis ion, digitt echn al syologies st em s nlik eed fastical Autnom at ick ing Gainand Cont rolage ( AGC) cir cuit s. Adap t ive equ alizer s, discu ssed next , need f ast t r aining t im es. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Modulation and enables net w or kin g p rEncoding ofessionals t oMethods un derst and for an d QAM im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu yst mod ry . Lear t o incor porcom at e int er net w or kin g ems t echn olog ies inon t o aquad LAN/ WAN envplit ir onm Man er n nf ixhow ed micr ow ave m unicat ion sy st are b ased r at ur e am udeent . Com plet ion e w it h new. These an d u pdat chapt on secur y , st age, optitical m odulat ( QAM) sy sted ems hav er e vs arious levitels oforcom plex y. net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net wpler Sim or kin sygstpems, rof essionals, such as ph r egar asedless sh ift of key exing pert ( PSK) ise. , ar e v er y r obu st and easy t o im plement because t hey h ave low dat a r at es. I n PSK m odulat ion , t he w av e's shap e is m odified in n eit h er Reader sw a g reatbut er un anphase. ding of The LANp and or kght ing,ofp ar larif ly am plit ud e ill norobt f rain eq uency, r atder herstin haseWAN can bneettwhou ast icu a sh t int hteim e. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Ianbbinar r oad yr ang ph ase e ofsh int if tegr k eyin al sy g st( BPSK) em s and , t he serv p hases ices, in forclud t h eing sindet e wailed av e st descr art at ipt eit ionher s, rev 0 or iew1 /quest 4. I n ions t o en su BPSK mre odu con latcept ion, comp on ly 1r eh b itenission t r ansm and itr tet edenpter ion, cyand cle (ad called dit ional a syrmb esou ol)r.ces In m f ororfu e-rtcomp her st lex udy . Cov m odulat erag ion e is sch alsoemext es, end m ed or entot han only 1 bit t o is new t ran n et smwor it t ed k ing perconcep sym b tol. s, but The also m odu t olat old ion er scheme , legacy syst qu adr emats,urpr e ovid ph ase in gshaifm t or key e in r ealist g ( QPSK) ic pictisursim e ofilar t het orealBPSK. w orHow ld n ev et weror , kinst ingead en vir of onm onlyent t wso in separ w hich at e pr of ph ase essionals st at es, oper QPSK at uses e. Tools fou rand ( 0, gu 1 / id 2,elines 1 / 4, an f ord opt 3/ 2) im, izing car r y syst in g 2em b itper s per for m sym ance b ol.w Lik ill incr e BPSK, ease pr odu ct QPSK is ivused it y an bd ecause im pr ov ofeiteff s riciency, obu st n ess. helpHow ing tever he r ,eader because m ake it m mor od e ulat in tes elligent only 2, cost bit s -peff ericient sy m bol, it decisions st ill is not for vertyh eir eff icient net w ork for s.h igh- speed com m unicat ions. Hence, high er bit r at es r equir e t he use of significant ban dw idt h. Ev en t houg h QPSK uses no st at e chang es in am plit ud e, it is som et im es called 4- QAM. Four levels of am plit ud e com b in ed w it h t he f our lev els of p hase r esult in 1 6- QAM. I n 1 6- QAM, 2 bit s ar e encoded on p hase chang es, an d 2 bit s are en cod ed on am plit ude ch anges, y ielding a t ot al of 4

bit s p er sy m bol. Figur e 20 - 9 illust r at es t he mod ulat ion con st ellat ions f or t hr ee com mon schemes—QPSK, 1 6QAM, and 64- QAM.

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Figu r e 2Table 0 -9of. Content Q PSK, 1 6 - QAM , a nd 6 4 - QAM M odu la t i on Con st e ll at ion s s I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

[ View full size im age]

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Ihar n Figur dw aree, 20pr - 10, ot ocols, each and u niqu ser e vphase ices inv is olv spaced ed . Fueq ndam uallyent in al b ot t ech h t he nology I an dinfQorcoor matdinat ion isesprinovtided he on raesult b r oad in gr ang m odeulat of int ionegr const al sy ellat st em ion. s and Th eserv angle ices, of in r otclud at ion ingindicat det ailed es tdescr he phase, ipt ion s, and rev t he iewdist quest ance ions t oom fr en su t he recent con er cept point comp indicat r eh enes sion t heand ampr et lit en ude. t ion, This and apad pr oach dit ional to m r esou odulat r ces ionf orcan fu rtbe her exp standed udy . t o Cov 64 - QAM erag eand is also 256 -ext QAM endor edhigh n ot er only . Altthoough new n64 et-wor QAM k ing is ver concep y popt s, ular butinalso bot ht ocable old erand , legacy w ir eless syst br oadb em and s, pr pr ovid odu inct g s, a2 m56or eQAM r ealist is ic also pictbur eine goft est t heed. realTh w e or high ld nerettwhe ordensit k ing en y vir in onm QAM,ent t he s inhig wher hich pr of essionals signalt o- n oise oper r atat io e.( SNR) Toolst hand at mgu u st id elines be m aint f or ain opted im izing t o meet systt he emr per eq uir fored m ance bit errwor ill rincr at es ease ( BERs) . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figu r e 2 0 -1 0 . Er r or Ra t e s f or PSK a nd Q AM Sy st em s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP How t h e dat a is encoded also p lays an im por t ant par t in t h e equat ion . The d at a is u su ally scr amCov bled, aned of a signif icant amt echn ount ologies of f orw ar r or cor rect ion ( FEC) ator a age is also t ran sm it t ed. erag cut t ing edge likde er opt ical n et wor k ing andd st Ther ef or e, t he sy st em can r ecov er bit s t h at ar e lost b ecause of n oise, m ult ipat h signals, an d int er fer enh ce. sig Cisco nificant rov em t inide BER is achieved using or aI ngiven at t h e Aut oredA by Syimp st ems, w orenldw leader in net w or king FEC f or tfhe t er n etSNR . r eceiver ( see Figur e 20 - 11) . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st rrye. Lear n how t o incor porin at st e int er netal w or t echn olog in t oed a LAN/ env ir onm ent .t a Figu 2 0 -1 1 . BER Aga Sign - tkin o-gNoise f oriesCod an dWAN U ncode d Da Com plet e w it h new an d u pdat ed chapt er s on it ys, st or age, opt ical net w or k in g, scalabilit y, Stsecur r ea m and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. [ View full size im age]

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Advanced Signaling Techniques Used to Mitigate Multipath Signals Sever al t echniqu es mak e d ig it al m odulat ion sch em es m or e r obust : QAM wit h d ecision f eedb ack equalizat ion ( DFE) , d irect sequence spr ead sp ect r um ( DSSS) , FDM, an d ort h ogonal fr equency div ision m ult iplexin g ( OFD M) .

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QAM withI ndex DFE •

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

I n wir eless QAM syst em s, DFE is used t o mit ig at e t he ef fect s of I SI cau sed by m u lt ip at h sign als. By Cisco Systems, Inc. When delay spr ead is p resen t , t h e echoes of p rev ious sym b ols cor r up t t h e sam p lin g in st an t f or t he cu rr ent sy m bol. Th e DFE filt er over samp les t he incom ing sig nal an d f ilt er s ou t t h e ech oed Cisco Press carrPub ierlish s. er: The com plex it y of DFE sch em es causes t hem not t o scale w it h in cr eases in ban dw idt h . Pub Dat e: Sep tem 1 1,DFE 2 003filt er ( t h e num b er of t aps) is p rop ort ion al t o t he size of t he d elay The com plex it y ofber t he I SBN: 158 705 -1 19 -2 spr ead . The num ber of r equir ed t ap s is pr opor t ional t o t he delay spr ead ( in second s) m ult iplied by t hePages: sym b11ol28r at e. For a QAM- based w ir eless syst em t r ansm it t ing in t he MMDS b and ( a 6 - MHz- w ide chann el) t o sur viv e a 4- µsec delay spr ead , 24 t ap s ar e requ ired. To equalize a syst em w it h 24 t aps, a DFE syst em n eeds 7 2 feed for w ar d an d 2 4 feed back t aps. I n add it ion t o t he n um ber of t aps need ed , t he com plex it y of t he m at h needed for each t ap in cr eases w it h t he num ber of t ap s. Theref ore, The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t he in cr ease in com plexit y becom es an ex pon en t ial f unct ion of t he car rier signal' s ban dw idt h. essent ial an d cu t t ing- edg e t ech nologies. Figur e 20 - 12 com par es t he com plex it y rat e of QAM/ DFE and OFDM. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Figu r e 2 0 -1 2 . Com pu t a t ion al Com ple xi t y of Q AM Ve r su s O FD M

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Spread Spectrum Spr ead sp ect r um is a m et hod com m only u sed t o m od ulat e inf orm at ion int o m anageable b it s t hat ar e sen t ov er t he air wir elessly . Sp read spect ru m w as inv en t ed b y film act r ess Hedd y Lam ar , w ho receiv ed an aw ar d fr om t h e gov ern ment f or t his accomp lish ment . She r et ains t h e pat ent t o •t his d ay. Table of Content s •

I ndex

IEssen nt e rn et w or k, ing chnologie H a ndbook th Edit ion t ially sprTe ead sp ect rs um refer s, Four t o t he concept of sp lit t in g in for m at ion over a ser ies of r ad io chann els or fr equencies. Gen er ally, t he n um ber of fr equ en cies is in t he r ang e of about 70 , and By Cisco Systems, Inc. t he in for m at ion is sent ov er all or m ost of t he fr equencies befor e being dem odulat ed, or com bined at t h e receiv ing end of t he r adio sy st em. Pub lish er: Cisco Press

Datse:of Sep ber 1spect 1, 2 003 Tw oPub k ind sptem read ru m ar e available: I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Dir ect seq uence sp r ead spect ru m ( DSSS) Frequ en cy hopp in g sp read spect r um ( FHSS) DSSS can pr ov ide h ig her dat a r at es, w it h access r at es up t o 11 Mbp s. FHSS sy st em s can achieve The u pdat ionBecause of t he b FHSS est - selling all- inone net whork ing gr ef erence rov cover agesyst of em s 3 Mbp s dated a redit at es. emp loys f r eq uencyoppin schem es,p m orides e indiv idual essent inge itt ech nologies. can ex ial ist an in da cu givt ten aredg ea w h out in t er f er ing w it h one an ot her. Howev er, direct sequ en ce sy st em s ar e m ore t oler ant of local int er ference. Wh en bot h sy st em s u se t he sam e t r ansmit pow er lev el, a DSSS sy st em has a low er - pow er spect ral densit y. This m eans t h at t h e sam e am ou nt of p ow er is ciseoss ov er v iew t echn olog ies essen t ialt ends t o n ett owor k ing tpr els,syf rom r adiatCon ed acr aw iders fof r eq uency r ange, w hich lessen heofession eff ect s als on at ot hall er lev local st em s nov ice t o ex pert . using t he sam e f r eq uency sp ect r um . chapt er sanalogy include tcov erag imspr poread t antspt opics like and EAP A comNew m only used o und er estof and ect r um is VoI t hatP of a ser ies of t r ain s depar t ing a st at ion at t h e same t im e. Th e pay load is d ist r ibu t ed r elat iv ely eq ually am ong t he t rain s. When a Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age t r ain arr iv es at it s d est inat ion, it s pay load is rem ov ed and collat ed . Dup licat ions of pay load ar e com mon sp r ead spectSy ru m so t hw atorwldw henide dat a ar rivinesnet exw cessively cort he ru ptI ned, oretfails t o arr iv e at Aut hinored by Cisco st ems, leader or king f or t er n . all, t he redu ndan cies inh er ent in t h is archit ect ur e p rov ide a m ore r ob ust d at a link . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat DSSS is net a signaling mret hod t hat av comp lex it t h e need f or em equalizat , a enables w or kin g p ofessionals t ooid unsderst and any dand im plem en t cont por ar yion. int erGenerally net w ork ing nar r ow band QPSK sig nal is u sed. This nar r ow band signal is t hen mu lt iplied ( or spr ead) acr oss t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork inga m uchst ry w id er band wid tt oh.incor Th e por am at ount um ed is exies pr essed 1 0 WAN ( SNR/env 10 )ir. onm ent . indu . Lear n how e intoferspect net wror kinneed g t echn olog in t o aas LAN/ Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Ther ef or e, if an SNR of 20 dB is r eq uired t o ach iev e t he appr opr iat e BER, t he t ot al spr ead and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all ban dw idt h needed t o t r ansm it a digit al sign al of 6 Mbp s is 600 MHz. net w or kin g p rof essionals, r egar dless of ex pert ise. This is n ot v ery band wid t h- eff icient . I n add it ion, t h e r eceiv er 's sam pling r at e needs t o be ab out Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e 10 0 t im es t h e dat a rat e. Th er efor e, f or t his h yp ot het ical sy st em, t he sam pling r at e also needs t o har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on be 6 00 m eg asam p les p er second. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tWit o en re con comp r eh eninning t ion, and ional r esou f orit hfuTr rt ain her N, st udy . h su DSSS, allcept t rains leav e en in sion an orand d er rbeteg w it hadTrdit ain 1 and endr ces in g w Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy depend in g on h ow m any chan nels t he spr ead sp ect r um sy st em allocat es. I n t he DSSS syst s,upr a m or e ay r ealist ic epict e of t he realn et hw or k ing enber vir onm entoad s in tw hich ar chem it ect re,ovid t h eintgr ains alw s leav in ur t he sam e or derw , or altld houg t he nu m of r ailr r ack s pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease can be in t he h und reds or ev en t housand s. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t hmeir net waccess ork s. ( CD MA) allow s sever al simu lt aneous t r ansm issions t o occur . Each Cod e div ision ult iple dat a st r eam is mu lt ip lied w it h a pseudor and om noise code ( PN code) . All users in a CDMA syst em u se t he sam e fr equency ban d. Each signal is sp r ead out and lay er ed on t op of each ot her and is ov erlaid using cod e spr ead ing in t h e same t ime slot . The t r ansm it t ed signal is r ecov er ed using t he PN code.

Dat a t r ansm it t ed by ot her users look s lik e w hit e n oise an d d rop s out du ring t h e r ecept ion phase. Any n ar row ban d noise is dispersed dur ing t he d esp reading of t h e dat a sig nal. The adv ant age of CMD A is t h at t h e am ount of band w idt h r eq uired is shar ed ov er sev eral user s. How ever , in syst em s t hat hav e m ult iple t r an sm it t er s and r eceiver s, pr oper pow er m anag em ent is need ed t o ensur e t hat one u ser d oes not over pow er ot her user s in t he sam e sp ect r um . Th ese p ow er m anagem ent issues ar e m ainly confin ed t o CMDA ar ch it ect ur es. •

Table of Content s

• FHHS

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

WitCisco h t he FHSS ar chit ect ur e, t he t rains leav e in a dif fer en t or der —t hat is, not sequ en t ially fr om By Systems, Inc. Tr ain 1 t o Tr ain N. I n t he b est of FHSS sy st ems, t rains t hat ru n in t o in t er f er ence ar e not sent out again un er: t il tCisco he inPress t er f er ence abat es. I n FHSS sy st ems, cer t ain f r eq uencies ( chan nels) ar e avoid ed Pub lish un t il t he in t er f er ence abat es. Pub Dat e: Sep tem ber 1 1, 2 003

I nt er ferI SBN: en ce1-t58 en705 ds-1t19 o -2 cov er m or e t han one chan nel at a t im e. Ther ef or e, DSSS sy st em s t end t o lose mPages: ore d11 at28 a f r om int er fer en ce, b ecause t h e dat a is sent ov er sequ en t ial chann els. FHSS syst em s hop bet w een chan nels in n onseq uent ial or der . The b est FHSS syst em s adj ust chan nel select ion so t hat highly in t er f er ed ch annels ar e av oid ed , as m easu red by ex cessiv ely low bit err or r at es. Eit h er appr oach is ap pr opr iat e and d ep en ds on cust om er r equ ir em en t s, w it h t h e select ion cr it eria pr imar ily being t hat of sev ere mu lt ip at h sig nals or an int er fer in g RF env ment The iron u pdat ed .edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

FDMCon cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing

pr ofession als at all lev els, f rom nov ice t o ex pert . I n an FDM syst em , t he available b andw idt h is d iv ided int o m u lt ip le dat a car r ier s. The dat a t o be t r ansm it t ed is t herens include d iv ided cov am erag ong tehese bcarr s. Because each carEAP r ier is t r eat ed New chapt of imsu por t antiert opics like VoI P and independ en t ly of t he ot hers, a fr equency g uar d b and m ust b e placed ar oun d it . This gu ard b and low er Cov s t h erag e bane dw of idt cutht ing eff iciency. edge t echn I n som ologies e FDM lik esyopt st em ical s, nup et wor t o 50 k ing perand centstof or age t he available ban dw idt h is w ast ed . I n most FD M sy st em s, indiv idual user s ar e segm ent ed t o a par t icu lar Aut h ored by Cisco ide or king f ors t capacit he I n t ery.n et subcar r ier ; t herefor e, t hSy eirstbems, ur st rwator e ldw cann otleader exceedint hnet at w sub car r ier' I f .som e subcar r ier s ar e idle, t heir ban dw idt h cannot be sh ared w it h ot her subcar rier s. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing OFDM indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Iand n OFD M ( see e 20 , m ulteipan le dcar r ier or et ones) ar e used divics idet hat t h eare dat essen a acr oss speed, t h isFigur book is a- 13) com plet u pt o-s d( at r ef er ence t o t het ot op t ial tthoeall av ailab le sp , sim ilarr egar t o FDM. er, in net w or kin g pect rofr um essionals, dlessHowev of ex pert ise.an OFDM syst em , each t one is con sid er ed or t hog onal ( ind ep en dent or un relat ed) t o t h e adjacent t ones and , t her efor e, does not r eq uir e a Reader w ill obt ain a gOFDM reat err eq unuir deres st an ding of LAN andarWAN or of k ing, p ar titicu e icient gu ard bsand. Because g uar d band s only oundn aet w set t ones, islar m ly or et heff har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov spect rally t h an FDM. Because OFD M is m ade up of man y nar r ow band t ones, nar r ow ban dided on a r oad r ang e of ades int egronly al syastsm emall s and ices, clud ing s, rev intber fer en ce degr p ortserv ion of t h einsig nal andet d hailed as lit descr t le or ipt noion ef fect oniew t h equest ions tr oemenaind su reer con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . of t he f requ en cy com pon en t s. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, t he m ake mors e in t elligent , cost - eff icient Figu help r e 2ing 0 -1 3 .r eader OFDM Tone decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

OFDMPages: syst em s use bu rst s of d at a t o m inimize I SI cau sed by d elay spr ead. D at a is t r ansm it t ed in 11 28 bu rst s, an d each bur st consist s of a cy clic p ref ix follow ed by dat a sy m bols. A t y pical OFDM signal occu py ing 6 MHz is m ade u p of 512 indiv idual carr iers ( or t ones) , each car ry ing a sing le QAM sym b ol per bu rst . The cyclic pr efix ab sor bs t r ansient s fr om p rev ious bu rst s cau sed by m ult ipat h signals. An addit ion al 64 sym b ols are t ran sm it t ed for t he cyclic pr efix . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of For each sy mb ol per iod, a t ot al of 57 6 sy m bols ar e t r ansm it t ed b y only 51 2 uniqu e QAM sy m bols essent ial an d cu t t ing- edg e t ech nologies. per b ur st . I n g en er al, b y t he t im e t h e cyclic pr efix is ov er , t he r esu lt in g w av efor m cr eat ed by t he com bining m ult ipat h signals is n ot a fu nct ion of an y samp les f r om t he pr ev ious b ur st . Hen ce, t her e Con is no I SIov . The cy clic efix olog m ustiesbeessen g reatt ial er tt ho an e delay spr ead of als t h e at m all ult ipat h sigf rom nals. cise er v iew s of pr t echn n ett hwor k ing pr ofession lev els, I n a 6MHz syst em , t h e indiv idual sam ple r at e is 0 . 16 µsecs. Ther efor e, t he t ot al t im e for t he nov ice t o ex pert . cyclic pr efix is 1 0. 24 µsecs, g reat er t h an t h e ant icipat ed 4 µ secs delay spr ead. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing VOFDM

edge t echn ologies lik e opt ical n et wor k ing and st or age

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n addit ion t o t he st andar d OFDM pr inciples, t he use of spat ial diver sit y can incr ease t he syst emet'swtor oler t o nologies noise, inHand t er f erbook ence,, Four and tm is calledrefer v ectence ored tOFDM I n t ern k inance g Tech h ult Edipat it ionh , signals. is a comThis pr ehensive hat (enables VOFDM)net . Spat ial d iv er sit y is a w idely accept ed t ech nique for im pr ov in g perf or man w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int erce netinw ork ing m ult ipat h signal ener virtonm ent ipat h sig nals a fun ctused ion ofint ht oday e collect ion of ing t echnologies. Mast he t er ms. s, Because con cep t s,mtult echn ologies, an ar d e devices ' s net w ork bou nced signals, t h at collect ion is dependent on t he locat ion of t he r eceiv er ant enna. I f t wo or . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent m or e ant ennas are placed in t he sy st em , each h as a d iff er ent set of mu lt ip at h sig nals. The Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, eff s of each annel y frplet om eonan e dant enn o et he t , sot ocar r iert op s tics h att hat m ighare t be unu tsab andectspeed, t h isch book is vaarcom u pt o-adtat r efnerex ence t he essen ial le t o on all one an t enna m ig ht be usable on an ot her. Ant enna spacing is at least 10 t im es t he w av elen gt h. net w or kin g p rof essionals, r egar dless of ex pert ise. Signif ican in a SNR ar eerobt b yding using ennnas. icallyp,ara tsecon d ant Reader s wt illg ain obtsain g reat unain dered st an of mu LANlt iple and ant WAN et w Typ or k ing, icu lar ly t h eenna add s about dB in LOS t solv and o 10 dB env ir onm t s.ion is pr ov ided on har dw ar e, pr3 ot ocols, andenv serirvonm icesen inv ed .upFutndam ent in al NLOS t ech nology inf oren mat a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Elements of a Total Network Solution The com m on elem en t s of a t ot al net w or k solu t ion ar e

• •

Pr em ises Table netof w ork Content s s I ndex

net or ks I nt e rn Access et w or k ing Tewchnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Cor e n et w or k s

PubNet lish er: w ork Cisco man Press agement Pub Dat e: Sep tem ber 1 1, 2 003

Deploy m en t I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Premises Networks Pr em ises net w ork s ar e v oice, d at a, or v ideo d ist r ibu t ion n et wor k s t hat exist or w ill ex ist w it hin tThe he su bscr ed iberedit p rem Tybpical point s allof demar ion beting w een access pand pr emcover ises net or ks u pdat ion ises. of t he est - selling in- onecat net w ork r ef erence rov ides agew of for t he p ur poses of t his discussion include ch annel b ank s, PBXs, rou t er s, and m ult iserv ice access essent ial an d cu t t ing- edg e t ech nologies. dev ices. Cu st om ercise pr em equip signals hewor hub , t r anslat es t hem intall o cust omer Con ovises er v iew s ofment t echnr eceives olog ies essen t ialfr om t o ntet k ing pr ofession als at lev els, f rom usable d at a, tand r ansm nov ice o ex tpert . it s r et ur ning dat a back t o t he h ub. The t r ansm it t er, t he r eceiv er , an d t h e ant enn a ar e gener ally housed in a com p act r ooft op un it ( RTU) t hat is sm aller t han a sat ellit e TV New Ichapt er s nt include e of imspor t ant P eand m inidish. t is mou ed on tcov he erag subscr iber' r oof in taopics locatlike ion VoI w her it wEAP ill h ave a clear LOS t o t he near est LMD S hu b sit e. I nst allat ion in clud es sem ipr ecision p oint ing t o en su re max im um eragof e of t ing t echn ologies lik e opt ical n et wor k ing and st or age per forCov m ance t hecut RF linkedge . h ored Sy st ems, or ldw ide( NI leader in f net king f or tlat heion I n,t er n etodulat . The inAut door u nit by , t hCisco e net w ork in t erfwace unit U) , p er ormwsor t he m odu dem ion, and in- b uilding w ire- line int er face f unct ions. I t also pr ov id es an in t er m ediat e f requ en cy t o t h e RTU. IMan n t ern et werf oraces k in g rTech Hand book t h Eden it ion , is ae com y int equ irnologies ed by end cust om ,erFour eq uipm t r equir t h e pr NIehensive U t o h averefer a brence eadt ht hat of enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing ph ysical and logical int er faces. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu rye. dLear n how incor por e int or kin t echn olog ies t o con a LAN/ ir onm ents. NI Usstar esign ed t ot oaddr ess a at r ang e er ofnet t arwget ed gsub scr ibers wh in ose nectWAN iv it y env r equir em ent Com plet e w it hT1 new d u pdat chapt er sany on ot secur , st or age, net or k inThe g, scalabilit m ight include / E1,anPOTS, Eted hern et , or her itstyandar d netopt w orical k int er w face. NI U pr ovy, ides t h is book is taercom pletgef un an ct d ion u p- t(od at ecar r efds. er ence op ics essen tand hesespeed, int er faces w it h in w or kin I WF) Dif fert oent thet ytpes of tIhat WF are car ds ar et ial t o all kining tphe rofNI essionals, r egar dless pert ise. cells and pr ov ide t h e appr opr iat e sign alin g. rnet eq w uirored U t o con ver t t he inpof ut sexint o ATM Com m on I W Fs in clud e 10 BASE- T an d T1 / E1 circuit em u lat ion . The NI U also h as an I F t hat is Reader w ill a gRTU. reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e t r anslatsed b yobt t heain CPE har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Access Networks Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals Access net w oroper ks are at e.t he Tools t r anspor and gu t and id elines dist r ib f orutopt ion im net izing w or ks syst t hat em br per id for ge m t hance e pr emises w ill incrnet ease w or k pr odu and t hcte ivcor it ye an n et d wim orpr k ov d em e eff ar iciency, cat ion p oin help t s. ing For t he t he r eader p ur poses m akeofmor t hise diniscussion t elligent,, tcost he pr - eff imar icient y decisions m ean s of for pr ov t hiding eir net t he w ork t ran s.sp ort f rom an access n et wor k p oin t of p resence ( POP) t o t h e pr em ises is r adio, an d t h e dist r ibut ion bet w een access net w or k POPs is eit h er f iber or r adio.

Core Networks

Cor e n et w or k s ar e t he p ublic or p r iv at e b ack bon e net w or ks t hat , in a g en er al sense, t he access net w or k oper at or s use t o con nect t heir m ult it ud e of r eg ionally dispersed POPs and t o int er con nect t o pub lic ser vice pr ov ider net w or k elem ent s. For t he p ur poses of t his d iscussion , t he point of dem ar cat ion bet w een t h e access net w or k and t he cor e net w or k is a cor e sw it ch t h at ser v es as an upst r eam dest inat ion point for a m ult it ud e of access net w or k br anches or elem ent s.

• Table of Content s Network Management •

I ndex

IThe nt e rn w or H aw ndbook , Fouren th t Edit ion h er g et lue t hk ing at tTe ieschnologie all t h e snet or k elem s t oget

an d su ppor t s t h e k ey in for m at ion p r ocessin g t ask s t hat m akeInc. a bu siness r un eff ect iv ely is t h e Net wor k Managem en t Sy st em ( NMS) , w hich By Cisco Systems, includes Op er at ion al Supp or t Sy st em ( OSS) f unct ionalit y . I n it s fu ll im plem ent at ion , t he NMS is an ex ionally com plex set of m od er at ely t o h ighly int eg rat ed soft w ar e plat f or ms. For t h e Pubcept lish er: Cisco Press pu rp oses of t h is ch apt er , t he elem en t m anag er s n ecessar y w it hin each syst em - lev el piece of t he Pub Dat e: Sep tem ber 1 1, 2 003 access net w or k ar e assu med, but t he over archin g NMS is bey ond t he scope of t h is chapt er . I SBN: 1- 58 705 -1 19 -2

28 sh ould pr ovide en d- t o- end f unct ionalit y t h rou ghou t b ot h t he w ir eless and I deallyPages: , t he 11 NMS w ireline element s of t he n et w or k , including t h e back bone an d t he cust om er pr em ises.

A n et wor k m anag em ent syst em per for m s ser v ice, n et wor k , and elem ent m anagem en t acr oss m ult iv en dor and m ult it echnolog y net w ork s, includin g The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Topology man agem en t Con nect iv it y m anag em ent Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Ev ent man agem en t New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP The f un ct ion s of t he n et w or k m anag em ent syst em can be fu r t her out lined as f ollow s: Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age An int egr at ed t opology m ap t hat display s an en t ir e set of n odes and link s in t he net w or k , Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . show n w it h m app ed alar m s I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat A st or e of net w or k - w id e ph ysical ( nod es/ link s) and logical ( cir cu it s/ PVCs) t opology for enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing inv ent or y t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu stArycust . Lear incor por at netnwetor kinkgan t echn olog ies in o us a LAN/ WAN env ir onm ent . omnerhow car et oint erf ace t o ep int rover ide wor d end - user st tat Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is ce book com e an d u p-MBS, t o- d at e r ef erand ence t ow tor hek/tlink op ics t hat Perf or man st atisistaics onplet PCR, SCR, CDVT, net st at u s are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. SLA r ep ort in g w it h cust om er par t it ioning and alert in g of cust om er v iolat ion s Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dwAlar ar e,mprcorr ot ocols, and serr oot v ices inv olv . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on elat ion an d - cause aned alysis a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions A nreetcon worcept k simcomp ulat ion o sion t est w h etrheterenat ion, pr oblem w as ely rcor t o en su r eh ten and and ad ditcom ionalplet r esou cesr ect f ored fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Trs, ouble t ickinet or ce man agement syst em pr ovid g ina g/ mworore kf r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease based on st at ist icst he collect ed, m w itake h cust ert elligent and net, wcost or k - view s pr oduPerf ct iv or it yman an dceimrepor pr ov tes eff iciency, help ing r eader morom e in eff icient decisions for t h eir net w ork s. Usag e- b ased billing for ATM connect ions Read- on ly CNM for v iew in g n et w or k an d conn ect ion

Deployment Tier 1 cu st om er s use Cisco's ecosy st em of deploy m en t par t n er s. Deploy m en t f or syst em s cover ing BTA, MTA, or nat ionw ide f oot pr int s requ ires t h e follow ing ar eas of ex per t ise an d r esour ces:

• •

Con st r uTable ct ionof( tContent ow er s,s mast s) I ndex

( FCC an d slocal com ,pliance f or ion RF, I nt e rn Licensin et w or k ingg Te chnologie H a ndbook Four th Edit

const r uct ion, an d access)

By Cisco Systems, Inc.

Sit e sur v ey ( RF env ir on ment evaluat ion )

PubI lish nt egr er: at Cisco ionPress ( select ion

an d acqu isit ion of var ious RF com ponent s)

Pub Dat e: Sep tem ber 1 1, 2 003

PrI SBN: ime 1( cu st omer eng agement t hr oug h con t r act ) 58 705 -1 19 -2 Pages: 11 28 Finance ( secu ring or pr ovisioning of pr oject f inancing )

I nst allat ion ( assemb ly of com pon en t s) Pr ovisioning ( spar e com ponent s) The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of g dsycu st em s edg e t ech nologies. essentBillin ial an t t ingCon cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Wireless Local-Area Networks (WLANs) This sect ion int rod uces wh at is m ost lik ely t he f ast est g r owin g w ir eless t ech nology t oday . The deploy m en t of Wir eless Local- Ar ea Net w ork s ( WLANs) is qu it e com m on in m an y en t erp rises. •

Table of Content s

•

I ndex

WLAN Overview I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

A W LAN is a dat a t r ansmission sy st em design ed t o off er t r adit ional LAN ser v ice using a w ir eless ph ysical layer . I n Sep t em b er 1999 , t h e I EEE r at ified t he 80 2. 11b st and ard , w hich is t he lish er: Cisco Press domPub inan t WLAN st and ard . The I EEE 802 .1 1 w or k ing gr oups con t inue w or k ing on t he evolu t ion of Pub Dat e: Sep t hese st andar dtem s. ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

The g oal of 11 80282. 11b WLANs is t o of fer m obile u ser s w ired Et h er net - lik e per for m ance, availabilit y , Pages: and t h rou ghp ut , as well as f r eedom fr om t h e w ir ed infr ast r uct ur e. Table 2 0- 4 p r ovides a br ief com par ison of WLAN st and ard s. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Tab le 2 0 - 4 . A B r ie f Com pa r ison of t h e Blu et oot h an d 8 0 2 .1 1 W LAN Stan Con cise ov er v iew s of t echn olog ies essen t ialda t ornds et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Blu et oot h 80 2.11 New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP P hy si ca l la y er FHSS FHSS, DSSS, inf r ared ( I R) Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age H op fre qu en cy 16 00 hops per second 2. 5 hop s per second Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Pow e r out pu t 10 0 MW 1 W I nDtaern t h Ed ehensive t a etrawtor esk in g Tech nologies Hand book , Four 1 Mbp s it ion , is a com pr11 Mb ps refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Ma x im um num be i ce t oologies, 26 t o 25 t echnologies. Mast err tof he dev t er m s, scon cep t s, tUp echn an d devicesUpused in0t oday ' s net w ork ing supp or.t e d n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . indu st ry Lear Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Se curi t y 0- b it , 40 - bit , an d 6 440 - bit t o 12 8- bit RC4 and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all bit net w or kin g p rof essionals, r egar dless of ex pert ise. Ra nge 30 t o 300 f eet 40 0 f eet indoor s, 10 00 feet Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e LOS har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on en rt ang v eresion 0 in clud ing det ailed descr V1. 0 ipt ion s, rev iew quest ions aCurr b r oad of int egr al sy st em s and serv V1. ices, t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst pr oviding in g ina Table m or e r2ealist Not eem t hs, e follow 0- 4: ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions fort ot h12 eir8-net ork s.r efer s t o d at a secu r it y alg or it hm s. 40 - bit bitwRC4 An 802 . 11 ran ge of 10 00 feet r efer s t o out door con dit ions. I ndoor con dit ions ar e m or e dif ficult f or t h ese t y pes of RF sy st em s. 80 2. 11 pow er out p ut of 1 W per m it t ed by t he FCC is subst an t ial, alt houg h m ost 8 02. 1 1

dev ices hav e a pow er out p ut of 100 MW or less. The m ax im um n um ber of dev ices supp ort ed depend s on t he d at a r at e p er d ev ice. The Cisco Air onet Prod uct s use 8 02. 11 . Alt hou gh t hr ee st andar ds ar e in use in t he U. S. , and an addit ion al t w o ar e in use in Eur op e ( Hy perLAN and Hy per LAN2) , t he FCC t hink s h ighly of t h e 802 .1 1b st andar d, and a close •r elat ion sh ip ex Table ist sofbContent et weens t he FCC and t h e I EEE, w hich b ack s t h e st andar d. •

I ndex

I nt e rn et s H a802 ndbook Four thing EditGr ionoup s. Table 2w0-or5k ing list sTetchnologie h e var ious .1 1, W ork By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Tab le 2 0 - 5 . 8 0 2 .1 1 St a nda r d W or k i ng Gr oup s

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

W ork i ng Gr ou p

Te ch nolog y St a nda rd

80 2. 11a

54 Mb ps, 5 GHz, r at ified in 1 999

80 2. 11b

11 Mb ps, 2. 4 GHz, r at if ied in 1999

The u 11d pdat ed edit ion Wor of t he b este- selling in-orone netains w ork ing r ef erence p rov ides cover age of 80 2. ld mod and r egallulat y dom essent ial an d cu t t ing- edg e t ech nologies. 80 2. 11e Qu alit y of ser vice 80 2.Con 11f cise ov er v iew I ntserof access Pr ot ocolt ial ( I APP) t echnPoint olog ies essen t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . 80 2. 11g 2. 4 GHz, h igher dat a r at e ( gr eat er t han 2 0 Mbps) 80 2.New 11h chapt er s include Dy nam ic cov f requ eragen e of cy im allocat por t ant ion and t opics t r ansm like VoI it pow P and er cont EAP r ol m echanism s 80 2.Cov 11i erag e of cutAut h en t icattion and secu rit t ing edge echn ologies likye opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The 8 02. 1 1 st an dar d is com posed of sev er al com ponent s and ser v ices t h at int er act t o pr ov id e Istnat t ern w or kilit inyg tTech nologies Fouroft ht he Ed it ionw,orisk astcom ionetmob ran sp ar en t t oHand highbook er lay, ers net ack.pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er he t er con cep echnent ologies, an d devices used in t oday ' s net w ork ing The 8 02. 1 1 WLAN d eftines t wmos,p ieces oft s, eq tuipm : indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, W ir el ess t h is LAN bookstisaat ion comor plet clieen antd—u The p- t o-wdirateless e r ef st er at ence ion tiso tthhe em t op ost icsbasic t hat com are essen ponent t ialoft oa all net w or w kin ireless g p rof net essionals, w ork . A wr egar ir eless dless LANofstex atpert ion ise. is any p iece of equipm ent t hat cont ains t h e 80 2. 11 pr ot ocol f unct ionalit y at bot h t h e MAC and phy sical layer s and t hat has a connect ion t o Reader s w ill obt ain a g reat er untder an ding of LAN n yet w ar ted icuin larbot ly thh et h e w ireless media. Typ ically, he st 8 02. 11 p rot ocol and f un ctWAN ion alit is or imk ping, lempent har dwsoft ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided w ar e and h ard w are of a Net wor k I nt er f ace Card ( NI C) . A w ir eless st at ion could be a on PC, a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions lapt op , or han dheld device. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag Access e is also poi nt ext (end AP)ed—nAn ot only access t o pnew oint nact et wor s ask ing a b ridg concep e bet t s,w but een also the w t oir old eless er , an legacy d w ir ed syst em net s,wpr orovid ks. An in g access a m or ep roin ealist t consist ic pictsurofe aofr adio, t he reala wwiror edldnet n et wworork kint ingeren face vir onm ( suchent ass Et in hwerhich net pr of essionals or ATM) ,oper and at bre.idgin Tools g sof and t wgu are. id elines Th e access f or optpoint im izing act ssyst as em t h e per base forst mat ance ion w forillt incr h e wease ireless pr odunet ct ivwitor y k, anpr d im ovid prin ovgeaccess eff iciency, t o t h help e w ired ing tnet he wr eader or k formmake u lt ip mor le w e irineless t elligent st at,ions. cost -W effhen icient an decisions access for poin t h eirt is net prwesen ork s. t , all com m unicat ion b et ween w ir eless st at ions or bet w een a w ir eless st at ion and a w ir ed net w or k client go t hr oug h t he access poin t .

WLAN Architecture

The 8 02. 1 1 ar chit ect ur e has f ive main com ponent s: Basic Ser v ice Set ( BSS) I ndepend en t BSS I nf rast r uct ur e BSS • •

Table of Content s

Dist r ibut ion syst em I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ex t ended ser v ice set

By Cisco Systems, Inc.

The b asic building block of an 80 2. 11 w ireless n et wor k is t he BSS. I t con sist s of w ir eless st at ions lish er: t hatPub com muCisco nicatPress e dir ect ly or in dir ect ly w it h one an ot her. Pub Dat e: Sep tem ber 1 1, 2 003

The in dependent is t h e basic WLAN t opology . I t is a set of st at ions t hat recognize each ot her I SBN: 1- 58 705BSS -1 19 -2 and est ablish com mu nicat ions in a p eer - t o- peer ar ran gem en t . Nodes com mu nicat e dir ect ly w it h Pages: 11 28 one an ot her and , t h er efor e, m ust b e w it hin ran ge of one anot her . An infr ast r uct ur e BSS has t he added fu nct ion of an access poin t . An access point allows client s t hat hav e conn ect ed t o t h e WLAN t o g ain conn ect iv it y out side t h e WLAN wh en t h e access point is connect ed t o t he wir ed net w ork . I t also ef fect ively dou bles t he r adiu s of t he w ir eless net w or k, The u pdat ion tof netmw ork r efcan erence of because t wed o dedit ev ice hatt he ar eb est con- selling nect ed allat ainmone ax imu disting ance compmrov unides icat ecover v ia t age he access essent point . ial an d cu t t ing- edg e t ech nologies. The d ist r ibu t ion sy st em is t he w ir ed n et w or k . I t allow s f or back bone conn ect iv it y for access Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom point s. nov ice t o ex pert . An ex t end ed ser v ice set is t he p rod uct of ov erlap ping infr ast r uct ur e BSSs, in w hich t h e access s include covdist erag e ofion im BSS. por t ant t opics likehav VoIePassociat and EAP point sNew can chapt p ass er t raf fic v ia t he r ibut Client s t hat ed w it h t heir r esp ect iv e APs t h us can est ablish en d- t o- end com mu nicat ion. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age The u niqu en ess of t h e WLAN t echn ology exist s at Lay ers 1 an d 2 of t h e OSI m odel, t h e phy sical Autahlink oredlay byerCisco Syect st iv ems, or ldw ide in net king he bet I n twereen n et .t h e MAC lay er and dat s, r esp ely . wThe 802 .1 1leader phy sical layweroris t hef or layter and t h e w ir eless m edium wh er e f r ames ar e t r ansm it t ed an d receiv ed. Th e phy sical lay er I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat pr ov ides t hr ee fu nct ions. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing tThe echnologies. Mast t he t er an m s,incon echn ange ologies, an d devices ork ing p hy sical lay er er pr ov id es t er fcep acet s, t o texch f r ames w it h t heused MACin layt oday er for' s tnet ranw sm ission indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent and r ecept ion of dat a. The p hy sical lay er uses sign al carr ier and spr ead spect r um m odu lat ion t.o Com plet w itahf ram newes anov du oniu secur it y p, hy st or age,lay opt net w in g, ier scalabilit t r ansm itedat erpdat t heed w irchapt elessermsed m . The sical er ical pr ovid esorakcarr sen se y, and speed, t h is book is a com plet e an d u pt od at e r ef er ence t o t he t op ics t hat are essen t ial t o all indicat ion t o t he MAC layer t o v er ify act iv it y . net w or kin g p rof essionals, r egar dless of ex pert ise. The 8 02. 1 1 st an dar d p rov ides f or t he follow in g phy sical lay ers: Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad ang of Uses int egrinfr al sy s and ices, in clud descr ipt ion iew quest ions I nfrra re ed— ar st edem ligh t t o tserv r ansm it bin ary ing dat det a atailed eit her 1 Mbp s (s, t herev b asic access t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . r at e) or 2 Mb ps ( t h e enhan ced access r at e) . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em FHs,SS— pr ovid Uses in g RF a msignals or e r ealist at 2.ic4 pict GHz urteo of t r ansm t he realit d at w or a at ld n 1 et and w or2k ing Mbpen s. vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease signals at 2. 4 help GHz ing t o ttrhe ansm it d atma ake at 1,mor 2, e5.in 5 t, elligent and 11, Mb ps. pr oduDctSSS iv it y—anUses d imRF pr ov e eff iciency, r eader cost - eff icient decisions for t h eir net w ork s. The 8 02. 1 1 MAC lay er pr ovid es reliable dat a deliver y for t he up per lay er s ov er a w ir eless ph ysical layer m edium . D at a d eliv er y is b ased on asy nchr onou s, best - ef for t , conn ect ionless deliver y. Her e ar e t h e m ajor at t ribu t es: Ther e is no guar ant ee of successfu l deliver y .

The 8 02. 1 1 MAC lay er also pr ov id es a cont r olled access m et hod t o t he shar ed w ir eless m ed ium v ia Carr ier Sen se Mult iple Access w it h Collision Av oidance ( CSMA/ CA) . CSMA/ CA is similar t o t he collision det ect ion u sed by 8 02. 3 Et h er net LANs. The 8 02. 1 1 MAC lay er also pr ov id es pr ot ect ion for t he d at a being deliver ed b y pr ov id ing secur it y an d p r iv acy ser v ices. Secu rit y is pr ovid ed by b ot h aut hent icat ion and encr yp t ion . •Wir ed Equiv alen Tablet Pr of ivacy Content( sWEP) is d ef ined as t he 8 02. 11 secu rit y pr ot ocol. I t s goal is t o achiev e •t he lev el of secur I ndexit y and p riv acy foun d in w ir ed n et w or k s. RF com mu nicat ions ar e open, so It rntansm e rn et w issions or k ing can Te chnologie be in t er sH cep a ndbook t ed. WEP , Four is th tEdit h e ion feat ur e u sed for dat a encr y pt ion bet w een t he client and access poin t . The minim um imp lem ent at ion is t he use of a st at ic 40 - bit or 12 8- bit RC4 k ey . By Cisco Systems, Inc. I n t he r ecent past , t h is encry pt ion m et hod had been com pr om ised. This at t ack has been docum ent ed in w h it e paper s av ailab le on t he I nt er net . This v uln er abilit y is m it igat ed in t he Cisco Pub lish er: Cisco Press im plem ent at ion s by m or e- rob ust secur it y m easur es. I t is im perat iv e t h at an y net w or k desig n Pub Datte: ber 1ion 1, 2of 003net w ork secur it y in a WLAN env ir onm ent . consider heSep evtem aluat I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Distribution Services The d ist r ibu t ion sy st em mu st be able t o offer cer t ain serv ices t o clien t s of t he W LAN. These dist r ibut ion ser v ices ar e t y pically pr ovid ed by access point s. Th e fiv e dist r ib ut ion ser v ices ar e The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Associat ion Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Disassociat ion nov ice t o ex pert . Reassociat ion New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Dist r ibut ion Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age I nt egr at ion Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The associat ion serv ice is r espon sib le for t h e logical connect ions bet w een an access poin t an d a I n t ern. etEach w or kclient in g Tech Hand t h Ed it ionbefor , is ae com ehensive refer ence client mu nologies st associat e w book it h an, Four access point it is pr allow ed t o send dat a tthat hr oug h netpoint w or kin ofessionals t o un derst d im plem cont em por ar yt he int er net w ork ing tenables he access intgoptrhe dist r ibut ion syst em and . Theancon nect ionen ist necessar y for d ist r ibut ion t echnologies. Mast er tehe er m s,dat con t echn ologies, d devices in tfoday net w ork ing syst em t o kn ow w her t o t send a cep t o at s,par t icular clien tan . The client tused yp ically orm s' san indu st ry ion . Lear incor netent w orerkin ies client in t o acan LAN/ WAN env ent . associat sernv how ice ont oce, w h por en tat hee int st aterion s tghet echn BSS.olog Each associat e wiritonm h one Com plet e wtit, hbunew d u pdat ed chapt er s on secur , stltor opt ical net w or k in g, scalabilit y, access poin t anan access point can associat e w it hit ymu ipage, le st at ions. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net wdor kin g p rofion essionals, pert ise.ion bet w een an access point and a client w hen The isassociat serv ice rtegar ear s dless d ow nofanexassociat t hat client no longer r equir es t he ser vices of t he d ist r ibut ion sy st em . Wh en a st at ion b ecom es Reader s w ill obt a gbegin reat eraun derassociat st an dingion of tLAN and WAN e n et or an k ing, p ar t icu lar lyagain. t h e Th e disassociat ed, it ain m ust new o com m unicat ww it h access point har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on access poin t m ay f orce a client t o d isassociat e b ecause of r esou r ce r est rain t s, becau se t he access a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions point is shut t ing dow n, or becau se t he access p oin t is n o long er available. Client s d isassociat e twohen en su re con cept r eh sion and r ion et enist ion, and adion dit ional r esou f or fuby rt her st udy . t hey leav e a comp net w or k.enDisassociat a not ificat and can b er ces inv oked eit her Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy associat ed par t y. Neit h er par t y can r efu se t er m inat ion of t he associat ion . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals Tools and egu elines opt im izing emaccess per for pmoint ance w ill incr Reassociat ion oper let s at a e. client chang it id s cur r en ft or associat ion w syst it h an , such as ifease it w an t s pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff t o again associat e w it h an access p oin t w it h w hich it w as pr ev iou sly associat ed . The icient decisions h eir ice netis w ork r eassociatfor ion tserv sims. ilar t o t he associat ion ser v ice, b ut it includes inf or m at ion ab out t he access poin t w it h w hich a m obile st at ion h as been p rev iously associat ed . Not e t h at a client requ ires t h e r eassociat ion ser v ice w hen it m oves t h rou gh t he ESS, loses cont act w it h t h e access point w it h w h ich it is associat ed , and w ant s t o becom e associat ed w it h a new access p oint . Wh en r eassociat ing, t he clien t pr ov ides inf orm at ion t o t he access poin t it is

abou t t o associat e w it h about t he access point fr om w hich it is ab out t o disassociat e. The new associat ed access point con t act s t he pr ev iously associat ed access p oint t o obt ain d at a t h at m ight need t o be for w ard ed t o t he client as w ell as ot her inf orm at ion r elev ant t o t he new associat ion. The client alw ay s init iat es r eassociat ion . The p r im ar y serv ice used b y an 8 02. 1 1 clien t is t he dist r ibut ion ser v ice. A client uses t he dist r ibut ion ser v ice ev ery t im e it sen ds dat a link lay er MAC fr am es acr oss t he d ist r ibu t ion syst em . The d ist r ibu t ion ser vice giv es t he clien t t h e necessar y infor m at ion t o r each t h e pr oper • Table of Content s dest inat ion BSS f or it s MAC fr am es. The t h ree associat ion ser v ices—associat ion, r eassociat ion, • I ndex and disassociat ion—p rov ide t he necessar y infor m at ion for t he dist r ibut ion serv ice t o op er at e. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Dist r ibut ion w it hin t he d ist r ibu t ion sy st em does not necessar ily inv olve any add it ional f eat u r es By Inc. ion ser v ices, bu t a client mu st be associat ed w it h an access point befor e t h e outCisco side Systems, t he associat dist r ibut ion ser v ice can successfully f or war d fr am es. Pub lish er: Cisco Press

ThePub in tDat eg re:atSep iontem serv ice connect s t he 802. 1 1 W LAN t o ot her LANs, eit her w ir eless or w ir ed . A ber 1 1, 2 003 net w or k por t al p er f orm s t he int egr at ion ser v ice. Th e int egr at ion ser vice allow s for con nect iv it y I SBN: 1- 58 705 -1 19 -2 bet w een t h ese f unct ionally un ique local ar ea n et w or k s. Pages: 11 28

Cisco Sy st em s p rov ides an ar ray of h ar dw are t hat en ables feat ur e- r ich, scalable, w ir eless LAN solut ions. Cu r rent ly , 8 02. 11 a and 8 02. 11 b solut ion s ar e available. Access poin t s, br idges, ant enn as, client adapt er s, and OSS and BSS solut ions are of fer ed. The in gedit list ion d escr Airallonet WLAN everence ices: p rov ides cover age of The fuollow pdat ed of ibes t he bt he est -Cisco selling in- fam one ily netof w ork ing dr ef essent ial an d cu t t ing- edg e t ech nologies. Cisco Ai rone t 1 2 0 0 — The Cisco Air onet 1 200 ser ies is t he flagship of t he Air onet lin e. I t is t he cise st an dar en erolog at ion - perf man man ageable, eliable WLANs. Con ov erd vfor iewnsex oft -t gechn ieshigh essen t ialort o n etce, worsecur k ing e, pr ofession als at rall lev els, f rom Inov t inice t egtrat es seam lessly wit h an exist ing net w or k as a wir eless ov erlay or cr eat es o ex pert . fr eest an ding all- w ireless n et wor k s, enabling m obilit y qu ick ly and cost - ef fect ively. The m odular and rad able m im pr ot ect s cut ropics rent and fu t ur netEAP w or k inf rast r uct u re New chapt er supg include cov plat eragf or e of por t ant like VoI P eand inv est m ent s. Comp lian t w it h I EEE 80 2. 11 a and 80 2. 11 b st and ar ds, t he Cisco Air onet 120 0 Cov ser ies erag allows e of cut fort ing b ot hedge singtleechn and ologies du al- lik band e opt conf icalignuretat wor ionk ing plusand f ieldstupg or age r adabilit y t o mod ify t hese conf ig ur at ions as y our requ irem ent s and t echnolog y ev olv e. The Cisco Air onet 1 200 Aut h ored byesCisco st ems, w orr uct ldwuide in net wcust or king f or w t he er nimu et . m m obilit y and ser ies creat a wirSy eless inf r ast re tleader hat pr ovides om ers it hI n mt ax flex ibilit y , enab lin g con st an t conn ect ion t o all net w ork resour ces f r om v ir t u ally an yw h er e I n t ernwetireless w or k inaccess g Tech is nologies deploy Hand ed . book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. s, con cep Air t s, onet t echn1ologies, an daccess devices used t odaya' ssecu net rwe,ork ing Cisco AiMast roneer t 1t he 1 0 0t er —mThe Cisco 100 ser ies point pr in ov ides indu staff ryor . Lear n how t ot oincor at e int er net kincom g t echn olog ies inyt oand a LAN/ WANy env dable, easyusepor WLAN solut ionwtor h at bines m obilit f lex ibilit w it hir onm t he ent . Com plet h new anfdeat u pdat chapt s on y , pr st or age, opt ical net w or k inant g, ag scalabilit enteerwpritiseclass ur es ed requ irederby n etsecur w or k it ing ofession als. Tak ing adv e of t hey, and speed, booksecur is a itcom plet ant dheu po- d at efter o t he itt op icsailable t hat are t ial t o all Cisco wt hiriseless y suit e ef or st rtong este ren erence p riset secur y av andessen t h e Cisco net w or kinsof g ptrof essionals, dless ex pert ise. I OS w are for easer egar of use andoff amiliar it y, t he Cisco Air onet 1 100 series access poin t deliver s m anageabilit y , per for m ance, inv est m ent pr ot ect ion, and scalabilit y in a cost Reader w ill ain age a g reat der st al ancost ding of of ow LAN et w or Air k ing, p ar t icu0 lar the effsect iv eobt pack w it hera un low t ot nerand sh ipWAN . ThenCisco onet 110 serlyies f eat ur es har dwaarsing e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided le, u pgr ad able 802 . 11b r adio, int eg rat ed div er sit y dipole an t ennas, an d an inn ovaton iv e a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions m ount in g sy st em for easy inst allat ion in a var iet y of locat ion s and or ien t at ions. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr oduNO ct ivTE it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The p r eceding Airon et pr odu ct descript ion s ar e fr om t he Cisco Sy st em s Web sit e. For m or e infor m at ion, see w w w .cisco. com / en/ US/ pr oduct s/ hw / w ir eless/ in dex. ht m l.

Summary A b asic under st andin g of w ir eless concep t s is necessar y t o ensur e t h at y ou m ake t he cor rect choices w h en designin g w ir eless net w or ks. A good un derst and ing of t he b asics is helpf ul w h en y ou' re t ry ing t o und er st and an ex ist ing net w ork t hat you m ight need t o t r oub leshoot . When •t r y in g t o det er Table minofe Content high er s- lay er net w ork b eh avior , t h e eff ect of t he low er- lay er net w or k and it s •idiosyn cr asies I ndex are ver y imp or t ant . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

IByn Cisco a new n et worInc. k d esign , it 's im por t an t t o det erm ine t he app r opr iat e sp ect r um , as w ell as Systems, det er min e t he ab ilit y of y our net w ork t o coexist w it h ot her w ir eless comm u nicat ion s. When y ou' re t ry ing t o locat e less- t han- op t imu m per for m ance in a w ir eless net w ork , a solid Pub lish er: Cisco Press un derst an ding of t he spect r um u sed is im por t ant . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 58 705 -1 19 -2 decision is select in g t h e har dw ar e. Ant enn a, cable, and har dw ar e Anot h er cr it1ical design select ion Pages: ar e 11 p 28art of t he design , and y ou mu st be car efu l t o select t he cor r ect com pon en t s based on t he g oals of you r net w or k desig n.

The lim it at ions of NLOS com m unicat ions an d t he m et hods av ailable t o over come t hem ar e crit ical w h en y ou select a w ir eless t ech nology . Mod ulat ion met hod s, sch em es t o m or e eff ect iv ely enable t h e use of lim it ed spect ru m, and t he p r ev ent ion of in t erf er ence ar e all consider at ions t hat The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of m ust b e fact or ed in t o a desig n. essent ial an d cu t t ing- edg e t ech nologies. You m ust ident if y m any com ponent s w hen d ev eloping a t ot al net w or k solu t ion. Reg ard less of t h e equipm ent or ov t echnology oices, t hese ar e t he enwor ef itksing of w d ep entlev : els, f rom Con cise er v iew s ofcht echn olog ies essen t ialend t o nbet prireless ofession alsloym at all nov ice t o ex pert . I t com pl et e s t h e access t e chnol ogy por t fol io— Cust om ers com m only use m or e t han New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP one access t echn ology t o ser vice v ar iou s par t s of t h eir net w ork an d dur ing t he migr at ion ph ase ofet heir net w ork s, wt echn hen upg r ading rs onn et a wor sch keding uled b asis. Wir eless let s a f ully Cov erag of cut t ing edge ologies lik eoccu opt ical and st or age com pr eh en siv e access t echnology por t folio w or k w it h ex ist ing dial, cable, and DSL tAut echnologies. h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . t w goes er e nologies cabl e a nd fi be r ca, nnot inh,erisent nat ur of w ir eless t hat tithat d oesn' t I n t ernI et or k inwghTech Hand book Four — t h The Ed it ion a com pr eehensive referisence r eq uir e w ires or lines t o accom m odat e t he dat a/ voice/ vid eo pipeline. As such, t h e syst em enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing carr ies inf orm at ion across g eog rap hic ar eas t hat ar e pr ohibit iv e in t er m s of dist ance, cost t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing, t im e.t oI tincor also por sidest t he erou issues ofies I LEC collocat indu staccess, ry . Learor n how at eep ints er netnwum or kin g st echn olog in t o a LAN/ion. WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Alt hou tgh ingisfees for plet access atded areas s, ics t owt hat er s,are andessen t ops t of and speed, h ispay book a com e antdo uelev p- t oat e r ef ersuch, ence tas o tm heast t op ial t o all bu ild in gs, is not un usual, t h ese f ees, t he associat ed logist ics, and con t r act ual agr eement s net w or kin g p rof essionals, r egar dless of ex pert ise. ar e oft en m inim al comp ar ed t o t he cost s of t r en ching cable. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e t inv olv s re duce t im e t oinv reolv veed nue —ndam Com ent panies cannology generat enion ue is in pr less t im e on har dwI ar e, pr oteocols, and dser v ices . Fu al t ech infeorrev mat ov ided t hr ou gh t he d ep loy m ent of w ir eless solut ions t han w it h com par able access t echnolog iesions a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest because a w ir eless syst em can be assem bled and br oug ht online in as lit t le as t w o t o t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .t hr ee houers. Cov erag is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich This t echn olog y let s ser v ice p rov ider s sell access w it h out h avin g t o w ait f or cable- t r en ch in g pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease oper at ions t o comp let e or for in cu mb en t p rov ider s t o pr ovide access or back haul. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for id t h es eir bnet w dba ork s.nd a cce ss e x t en si on— Wireless com m only bot h com pet es w it h an d I t prov roa com plem ent s ex ist in g b r oadban d access. Wir eless t echnologies play a k ey r ole in ex t end in g t he reach of cab le, f iber, and DSL m ark et s, and t hey d o so q uickly an d r eliab ly. I t also com mon ly pr ovid es a comp et it iv e alt er nat iv e t o b road band w ir eline or pr ovid es access in geogr aph ies t hat d on' t q ualify f or loop access.

Regar dless of t he p rov ider of a w ir eless sy st em , t h e fu ndam ent al elem en t s r em ain relat iv ely const ant : Dat a or net w or k Ed ge or access r out er • •

Tablemof Content s DSP mediu I ndex

( coax ial, odu lat,or/ d em oduion lat or , I nt e rn RF et w m or kedium ing Te chnologie s Hm a ndbook Four th Edit

ant enn a)

By Cisco Systems, Inc.

RF m an agement soft w ar e

lish er: Cisco Press Lik ePub ever y access m edium or t echn ology , w ireless h as it s pr os an d con s. Her e ar e some of t he pr os: Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

I t 's mu ch less ex pensiv e t o d ep loy t han t r en ching for cab lin g. I t 's mu ch q uick er t o deploy. A link can be u p in a cou ple of hou rs. Wir eless can g o w her e cables can 't , su ch as m ou nt ainous or inaccessib le t err ain. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of r ed t ap is edg inv olved d ep loym ent if r oof r ight s or elev at ion access are available. essentLess ial an d cu t t einge t echfor nologies. I t in volv es an in herent high d eg ree of secu rit y , an d ad dit ional secur it y layer s can b e add ed . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Wir id es nov eless ice t o pr exov pert . br oadban d m ob ilit y , p ort ab ilit y t hat t et h er ed access doesn 't pr ov ide. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What ar e t he main com ponent s of a w ireless sy st em ?

2:

I ndex is t h e w avelen gt h of an 850 MHz carr ier? What

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : What By Cisco Systems, Inc.ar e 4:

some con sid er at ions w h en choosing a t r an sm ission line?

What ar e t he t w o basic ant en na t y pes?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

What does t h e acron ym EI RP st an d f or ?

I SBN: 1- 58 705 -1 19 -2 Pages: 28 6 : 11What

is a Fr esn el zone?

7:

What ar e m ult ipat h signals?

8:

What ar e t he fiv e basic buildin g b lock s of an 80 2. 11 r ef er ence ar chit ect u re?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of f iv eedg serv oes t he d ist r ibu t ion serv ice off er ? essent ial9 :an dWhat cu t t inge ices t echdnologies. 1 0 : What ar e fou r m ain b en ef it s of using w ir eless t echn ologies? Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • ht t p: / / hom e. ear t h lin k. net / ~ aar eit er / int r ot o. ht m ( guide t o w ir eless I n t ern et ) •

Table of Content s

•• ht t p: / / ht t p. cs. ber keley. edu/ ~ g r ib ble/ cs29 4- 7_ w ir eless/ sum m aries/ in dex. h t m l ( UC Berk eley I ndex cour se in w ir eless) I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

• ht t p: / / w inw w w . ru t ger s. edu/ p ub/ Link s. h t ml ( wir eless link s) Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

• w w w .air linx . com / pr od uct s. h t m ( RF pr odu ct m enu) I SBN: 1- 58 705 -1 19 -2

Pages: 11 28

• w w w .allnet d ev ices. com / n ew s/ index . ht m l ( allNet Dev ices new s) • w w w .am er icasnet w or k. com / issues/ 97 issues/ 971 001 / 100 197 _fu t ur ebb. ht m l ( br oadban d's evolu t ion ) The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. • w w w .b r oadband for um . com ( cab le br oadban d f or um ) Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom ice t o exirpert . / cn n/ w cii. ht m ( WinSt ar pr ess r eleases) • w w wnov .b usinessw e. com New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP • w w w .com et . colum b ia. edu / ~ an gin/ e69 50/ coolsit es. ht m l ( wir eless t op ics h ome page) Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age h ored by Cisco st ems, w or • w w wAut .ct im ag. com / ( CTISy new slet t er ) ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat •enables w w w .d at net a.wcom or kin / t ugt or p rials/ ofessionals w eb_conn t o ect un ion. derst htand ml (an wirdeless im plem w eb enttutcont or ial) em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . •Com www .d ect com/an sitdem ap. ht ( DECTw plet e wwiteb. h new u pdat edmchapt er s eb) on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. • w w w .d nspub lishin g. com / r c/ r cin dex. cfm ( recipr ocal com p en sat ion sit e) Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har ar e, pr ot ocols, anddect ser2v .ices olv ed . FuDndam • w wdw w .er icsson. com / BN/ ht m inv l ( Er icsson ECT) ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov e gov is also end Com ed n m ot on_ onlyCar t orier new n et wor ing concep t s, k/ but alsot . tht om old , legacy • w werag w .f cc. / Buext reaus/ / Repor t s/kFCCSt at e_Lin recen l (er FCC car r ier syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in w hich dat a) pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient •decisions w w w .f iber linw e.ork com foropt t hicson eir net s. ( Fiber opt ics On lin e) • w w w .g bm ar ks. com/ w ir eless.h t m ( Goodm an' s Wir eless Telecom m lin ks) • w w w .g lobalw ir elessnew s. com / ( RCR Global Wireless New s)

• w w w .h er r ing. com / m ag/ issu e4 8/ com m. ht ml ( Er icsson's br oadban d plans) • w w w .h om et oy s. com / ht in ew s/ oct 99 / art icles/ allied/ allied .h t m • w w w .in t er net t elephon y. com ( I n t er n et t eleph ony ) •

Table of Content s

•

I ndex

I• nt w or ing Te chnologie H a ndbook , Four th Edit ion ch iv e/ 7. 06 .9 8. ht m l w ewrnwet.in t erk net t elephon y.scom / archiv e/ feat ur ear

( FSAN over view )

By Cisco Systems, Inc.

• w w w .it . k t h. se/ ed u/ gr u/ Fing er inf o/ t elesy s. f in ger/ Mobile. VT96 / DECT. ht m l ( DECT) Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

• w w w .it u . in1-t /58 im705 t / 2r adiodev / pr oposals/ in dex. h t m l ( I TU w or ld rad io st and ard s) I SBN: -1 19 -2 Pages: 11 28

• w w w .m ob ilecomp ut ing .com / ( mob ile com pu t ing and comm u nicat ion s) • w w w .p honezone. com/ t ut or ial/ next g en . ht m ( next - g en er at ion ph one syst em s) The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. • ht t p: / / w w w - st ar. st anf or d. ed u/ ~ osam a/ lin ks. ht m l ( sing le- chip 2. 4 GHz rad io) Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom • w w wnov .t ekice . com Measur t o /ex pert . ement / App_ Not es/ ap- Wir eless/ w elcom e.h t m l ( wir eless dig it al m odulat ion ) New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP • w w wCov .t elecom eb. com/ / ( Com mu nicat ions ) erag ewof cut t ingctedge t echn ologies likToday e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . • w w w .t i. com / sc/ d at a/ w ireless/ pan os1 . pdf ( wir eless sy st em s and t echnolog y over view ) I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing • w w w .t i. com / sc/ d ocs/ w ir eless/ cellt er m . ht m ( glossar y of w ir eless t er m s) t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . plet e w. org it h new an dt ouevolv pdat ed er s on •Com www .t iap ( guide ingchapt w ireless sersecur vices)it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. • w w w .t r. com / ( Telecom m un icat ion s Repor t s) Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on •awbwr oad w .t rio. ca/eannu t hr m ( ices, Ont arinio, Can ada eless andiptmion obile r esear r ang of intal/ egr alust sys/ st m emobsat s and. htserv clud ing detwir ailed descr s, rev iew ch) quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy • w w w .w ap for um . or g/ w hat / t echn ical. ht m ( WAP f oru m specs) syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr it y rof anor d um im pr ov e/ w effpficiency, help eadert umt orials) ake mor e in t elligent , cost - eff icient • wodu w w ct .wivebp . com _w ir eless. hting ml t( he wirreless decisions for t h eir net w ork s. • w w w .w ir elessdat a. or g ( wir eless dat a f oru m) • w w w .w ir elessdat a. or g/ new s/ cu rr ent t x t . asp ( cu rr ent new slet t er )

• w w w .w ir elessdesign online. com ( Wireless D esign On lin e) • w w w .w ir elessweek. com / indu st ry / ind t oc. ht m ( Wireless W eek ind ust ry in for m at ion and st at ist ics) • w w w .w ow - com Table. com of Content / ind exs . cfm ( CTI A w ir eless w eb pag e: Wor ld of Wir eless) •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

• w w w .w ow - com . com / w ir elesssur v ey / 1 298 dat asur vey . pdf ( 199 8 U. S. w ireless su rv ey) By Cisco Systems, Inc.

• w wPub w .zd netCisco . comPress / an ch ord esk / st or y/ st or y _13 84. ht m l ( su rv ey of access t ech nologies by ZD lish er: Anchor desk) Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 28 / int week / pr int / 97 101 3/ 15 889 7. ht m l ( Oct ober 19 97 su rv ey of access • w w w Pages: .zd net11 . com t echnologies)

Regulations and Government

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. • w w w .b r oadband - gu id e. com / lw/ reg/ in dex. ht m l ( Pen nw ell pub licat ions) Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . • w w w .com m now . com / 3 rd _Gener at ion. ht m l ( art icle abou t TR- 45 w ork shop on I MT- 200 0) New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP • w w w .f cc. gov / b andw idt h / ( FCC b andw idt h h ome p age) Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age ems, w orile ldw ide leader net w or 2king t heR/I T n tIernit n iat et . ive] ) • w w wAut .it uh. ored ch / imby t / (Cisco I n t er nSy atst ion al Mob Telecom m uninicat ions000 f [orI TU I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat w or kin g osm p r ofessionals t o rt un. hderst d imrplem en t cont •enables w w w .n tnet ia. doc.g ov/ hom e/ alloch t ml (and U. S.anspect um char t ) em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, WLL and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. •Reader w w w .an s. ain co. uk regist locloop/ d efand ault .WAN ht m #ncont ent s ( LLp ar com p et iont h) e s walysy ill obt a /gpub reatlish/ er un der stered/ an ding of LAN et w or k ing, t icu laritly har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions •t ow w .gre lobalt ony . com / arsion chives/ GT5 98cov . htional m l ( WLL eatfuu rt r e) enwsu con eleph cept comp r eh en andGT59 r et en8/t ion, and aderdit r esoucover r ces ffor her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst s,t er prnet ovid in g a m y. orcom e r ealist t hes/ realw e1. or ldhtnmetl w( Febr or k ing onm entt -sgener in w hich • w wem w .in t elephon / con ic t enpict t / hturmel/of f ocu f eat ur uaren y 1vir 998 nex at ion pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease WLL) pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. • w w w .isir .com / w ireless/ ( WLL w or ld ) • w w w .n t ia. doc.g ov/ f or um s/ wir eless/ index .h t m l ( WLL for um )

• w w w .v er t icom . com/ cieee_1 / index .h t m ( St ev e Gold berg 's I EEE t alk on w ir eless LL) • w w w .w av esp an. com/ solut ion s/ u lt ram an .sht ml ( Wavespan St r at um 1 00)

LMDS/MMDS (Wireless Cable) •

Table of Content s

•

I ndex

•I nt htetrn p:et/ /wbu ech .coms /Ht elecom f r eet elecom or ksin ingesst Te chnologie a ndbook/, bt Four th Edit ion 990 2. ht m l ( hist ory of MMDS) By Cisco Systems, Inc.

• ht t p: / / gr ou per. ieee. or g/ gr oup s/ 8 02/ 1 6/ ( I EEE 802 . 16 Broad Band Fix ed W ir eless h ome page) Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

• ht t p: / / nw est . nist .g ov/ ( Click New s f or cur rent st andar d s act iv it y ) I SBN: 1- 58 705 -1 19 -2

Pages: 11 28

• ht t p: / / nw est . nist .g ov/ t ut or ial_et s. pd f ( a good LMDS cont ex t br ief in g) • w w w .am er icasnet w or k. com / issues/ 98 issues/ 980 801 / 980 801 _lmd s.h t m l The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t inge t ech nologies. • w w w .am er icasnet w oredg k. com / issues/ 99 su pplem en t s/ 9 906 01lm ds/ 99 060 1_t oc. ht m cise ovacom er v iew s of t echn ies essen ialhtt m o nl et wort hk ing ofession als at all lev els, f rom • w w wCon .cabledat new s.com / wolog ireless/ cm ic1t2. ( Nor Am pr erican MMDS t r ials) nov ice t o ex pert . chapt erreaus/ s include cov erag e of im por t ant t opics like VoI and EAP • w w wNew .f cc. gov / Bu Wir eless/ Fact sheet s/ lm ds. ht m l ( FCC f actPsheet on LMD S auct ion r esult s) Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age • w w w .n m cf ast .com ( I BM and New Med ia par t n er in MMDS) Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . ern eteledot w or k incom g Tech nologies Four Ed it ion , lis( a com pr ehensive •I nwt w w .t . com / 10 97/ fHand eat urbook es/ t d,c1 097tthelcos. ht m BellSout h MMD S wrefer r it euence p) t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing •indu w w st w .W .com / index . ht m por ( t he h ome page or t he Wireless ion) ry .CAI Lear n how t o incor at eWCA's int er net w or kin g t fechn olog ies in t oCable a LAN/Associat WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all • w w w .w ebp rof or um . com / nor t el4/ ( Nor t el t u t or ial on LMDS) net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e • w w w .zd net . com / int week / pr int / 97 063 0/ inw k 000 9. ht m l ( br oadban d w ir eless alt ern at ives) har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cordless Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease •prwodu w w ct .biv r oadband it y an d im - gu pridov e.ecom eff iciency, / w i/ t echu help pdat inge/ tthe echup r eader jf 98.m htake ml (mor wir eless e in t elligent in- b uilding , costt-elep eff icient hone decisions syst em s) for t h eir net w ork s.

Satellite

• ht t p: / / sat - nd .com / new s/ ( sat ellit e new s) • ht t p: / / t cpsat . gr c. nasa.g ov/ t cp sat / ( TCP ov er sat ellit e WG) • w w w .d at a. com / issue/ 990 707 / sat ellit e. h t m l ( I n t er n et sat ellit e link s) •

Table of Content s

•• w w w .ee. su rrI ndex ey .ac. uk / Personal/ L.W ood/ const ellat ion s/ ( t he or bit s) I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Inc. / m ag/ issu e4 8/ space. h t m l • wCisco w w .hSystems, er r ing. com

( Lor al por t r ait )

Pub lish er: Cisco Press

• w wPub w .ir idium . com/ in dex. h t ml ( I r idium hom e pag e) Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 11or 28g/ m obile. ht m ( Mobile Sat ellit e User s Associat ion ) • w w w Pages: .m sua.

• w w w .p r oject 77. com Pr oj ect 7 7 ( I r idium pr icing ) The editcom ion of he bview est - selling in• w w uwpdat .sat ped hone. / ( tover of p rogallram s)one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. • w w w .sat p hone. net ( I r idium ser v ice p rov ider sat ellit e w ar ehouse) Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . • w w w .sk y br id gesat ellit e.com / ( Sky Br id ge) New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP • w w wCov .sk yerag repor e tof . com/ cut t ing ( resear edgecht echn and ologies r ep ort inlikg ef or optt hical e sat n et ellit wor e kind ingust and ry ) st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . • w w w .spot beam. com / lin ks. ht m ( I n t er n et and sat ellit e link s) I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing •t echnologies. w w w .spot beam. com m ansum m cep ( GEO mar y) Mast er t/he t er m s,. ht con t s, sum t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, • w w w .spot beam. com / m ansum 99. h t m ( I n t er n et and I SP sum m ar y) and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. • w w w .t echw eb. com/ se/ dir ect link . cgi?NWC1 9980 315 S001 1 ( sat ellit e insecur it y ) Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a r angeb. e ofcom/ int egr stlink em s. cgi?NWC1 and serv ices, clud ing 7det ailed descr reves) iew quest ions • wbwr oad w .t echw se/al dirsy ect 9980in315 S001 ( br oadban d ipt Kaion sats,ellit t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy •syst w wem w .w d. net / sat . ht ( sat ellit v oice sywstor em s,izar pr ovid in/g~ av vmaughn or e r ealist icmpict ur e of et he realld com n et wpar or kisons) ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Modulations

• ht t p: / / div a. eecs.b er k eley .edu / ~ lin nar t z/ MCCDMA. ht m l ( OFD M d ef init ions)

• ht t p: / / pr op agat ion. jp l.n asa. g ov/ p rop db/ HELP/ CLOUD. HTM ( ef fect s of clou ds an d r ain) • ht t p: / / sss- m ag. com / fav link s/ in dex. ht ml ( man y m odulat ion link s) • ht t p: / / w ir eless. st anf ord . ed u/ r esear ch .h t m l ( St anfor d Univer sit y w ir eless r esear ch) •

Table of Content s

•• w w w .cat v . orI ndex g/ m odem / t echn ical/ of dm . ht m l ( OFD M, t h e next up st ream m odu lat ion) I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Systems, Inc. • wCisco w w .ee. mt u. ed u/ cour ses/ ee4 65/ g r oupe/ index . ht m l

( CDMA class)

Pub lish er: Cisco Press

• w wPub w .gDat r .ssr .u pm . es/ ~ ana/ of dm _link s.h t m ( OFD M sit es) e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 11h. 28se/ csee/ sp / pr oject s/ ofdm / of dm . ht m l ( OFD M d escr ip t ion) • w w w Pages: .sm . lut

Interfaces The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent d cu14t t ingedg e taz. echhom nologies. • ht t p: /ial / cxan 6673 a.chn d1. e. com / 13 94I n for m er / 99 080 0. ht m 1 394 ( n ew s h om e page) er v iew/scomp of t echn essen t ial4 t over o n etview wor k) ing pr ofession als at all lev els, f rom • ht t p:Con / / skcise ip st ov one.com con .olog ht m ies l ( I EEE 139 nov ice t o ex pert . erope.cisco. s include com cov erag e /ofpub imlic/ por4t59/ ant 8t.h opics VoI • ht t p:New / / w wchapt w - eur / w arp t m l like ( HSSI ) P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age • w w w .m f sd at anet . com/ m f s- in t er n at ion al/ hssi. ht ml ( HSSI ) Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . ern et w or k inmg.com Tech/ nologies Hand book •I nwt w w .sdlcom ( HSSI PCI m odu le), Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Glossary Terms a dj a cen t cha nne l. A chan nel or f r eq uency t hat is dir ect ly ab ove or below a specific chan nel or f requ en cy . •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

a m p li t ude . By Cisco Systems, Inc. The m ag nit ud e or st r en gt h of a v ar ying w av efor m . Ty pically , t his is repr esent ed as a cu r ve x - axis.

Pub along lish er: Cisco a g rPress aph' s

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

a na log si gna l . The r epr esent at ion of inf or mat ion w it h a cont in uously v ariab le phy sical quant it y, su ch as v olt age. Becau se of t his const ant ch ange of t he w av e shape as it passes a giv en p oint in t im e or space, an analog sig nal m ay hav e a vir t ually ind ef init e n um ber of st at es or v alu es. The u pdat edit ions w ofitthhea bdest selling all-wh in-ich oneis net ing as r efaerence p rov ides cover age of e, This ed cont rast igit-al signal, expwrork essed squar e w av e and, t her ef or essenthas ial an d cu t t ingedg e t ech nologies. a v er y lim it ed n um ber of discr et e st at es. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice a nt e nna . t o ex pert . New chapt er st ran include e of im like VoI P and A d ev ice for sm it tcov in gerag or receiv ingpor a trant adiot opics fr equency ( RF) . AntEAP ennas are d esign ed f or specif ic and r elat iv ely t ig ht ly d ef ined f r eq uencies an d ar e q uit e v ar ied in design . An Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age ant enn a f or a 2 . 5 GHz ( MMDS) sy st em w ill n ot w or k f or a 2 8 GHz ( LMDS) d esign . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat a nt e nnanet g ai enables w n. or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing The m easur e of an ant enna assem bly per for m ance r elat iv e t o a t h eor et ical ant enn a called indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . an isot r op ic rad iat or ( r adiat or is an ot her t er m for ant enna) w hen ex pr essed in d Bi. Cert ain Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, ant enn a d esigns feat ur e hig her per for m ance r elat iv e t o vect or s or fr equ en cies. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e ba ndw i dt h. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e uency of int egr al synstecessar em s and ices, clud ingmdet ailed s, .rev ions The f r eq r ange y t oserv conv ey ain sig nal easur ed descr in heript t zion ( Hz) Foriew exquest am ple, t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . v oice sign als t yp ically r equir e app rox im at ely 7 k Hz of b andw idt h, and d at a t r af fic t y pically Cov erag is es also extox end n ot50 only t oofnew n et wor concepmeanin t s, but g also oldt erm er , legacy r eqeuir appr imed at ely k Hz b andw idt hk. ing A second f or ttoh e band wid t h is syst emt he s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in w hich act u al w idt h or am oun t of spect r um u sed by a w ir eless sy st em . pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. br oad ban d. I n general, an RF sy st em is deemed br oadb and if it has a const ant dat a rat e at or in excess of 1. 5 Mbps. I t s cor r espon ding opp osit e is nar row b and.

br oad ca st . I n general, t his is t he opposit e of nar r ow cast and im plies t hat a sig nal is sent t o m an y point s at t he sam e t ime or is t r ansm it t ed in an omn idirect ional p at t ern . •

Table of Content s

•BTA.

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

TradInc. ing By CiscoBasic Systems,

Area. An ar ea or f oot pr int in w h ich an en t it y is licensed t o t r ansm it it s fr equ en cies. BTAs w er e est ablished b y Ran d McNally and ar e def in ed as coun t y lines. Rand McNally licensed it s m ap ping dat a t o t h e FCC for ease of desig nat ion for sit e licenses.

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

CDM A. Pages:

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Cod e div ision m ult iple access. A t r an sm ission sch em e t h at allow s m ult iple u ser s t o sh are t he sam e RF ran ge of f requ en cies. I n ef fect , t he sy st em div ides a lar ge set of f requ en cies int o a sm aller r ang e and div ides t he dat a t ran sm ission am ong t hem . Th e t r ansmit t in g dev ice d ivides t h e dat a am ong a p reselect ed set of non seq uent ial f requ en cies. The r eceiv er The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t hen collat es t h e v ariou s dat a pieces f rom t he d ispar at e f r eq uencies in t o a coh er ent dat a essent ial an d cu t t ing- edg e t ech nologies. st r eam . As par t of t h e RF sy st em set up , t he r eceiv er com p onent s ar e adv ised of t h e scr am bled ord er of t he incom ing fr equencies. An im por t an t aspect of t h is schem e is t h at t he cise receiv er s olog out ies anyessen sign al ot ther t h wor an tkhe specified or all a given Con ov er er vsyst iew sem of ftilt echn t ial o n et ingones pr ofession als fat lev els, f rom t r ansm ission. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP cha nne Covl.erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age A com m unicat ionsSy p at w id ew enoug h t oleader per mitin anet sing le king RF t rf or ansm Aut h ored by Cisco sthems, or ldw ide w or t heission. I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing coax ia l cab leMast . t echnologies. er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . A teypweit h of new cab le a cen coner duct or secur t h at is oun dedopt b yical a shield. Com plet anwdituhpdat edt er chapt s on it ysur , stror age, net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. conv erst er . obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Reader w ill har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on RFr ang sy steem h ave t wsy o fu ndam ent al fr equencies: t h at is sent over t h es, air carr quest ier a b r oad ofs int egr al st em s and serv ices, in clud one ing det ailed descr ipt ion rev( iew ions fr equ en cy ) , an d on e t hat is sen t b ack and for t h bet w een Cisco equipm ent and t he t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . anteenn as ( int m ed e fronly equency ) . This is pker f orm ed byt s,a but con ver an Cov erag is also exter end ediat n ot t o new n et wor ing concep alsot er, t o also old ercalled , legacy up con ver t er, dow nconv ert er , or t ran sv ert er . Th e int erm ediat e f r eq uencies ar e split inhich to a syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w high er and low er f r eq uency t hat ar e used f or eit her t r ansm ission or r ecept ion of dat a pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease bet t him e ant enn a assem blyhelp an ding Cisco ev ices.m ake mor e in t elligent , cost - eff icient pr odu ct iv w it yeen an d pr ov e eff iciency, t he dr eader decisions for t h eir net w ork s. dB. Decib el. A un it f or m easur ing r elat iv e pow er r at ios in t erm s of g ain or loss. Unit s ar e exp ressed in t er m s of t h e logar it hm t o base 10 of a rat io and t y pically ar e ex pr essed in

w at t s. dB is not an absolut e v alue. Rat h er , it is t he m easur e of pow er loss or gain bet w een t w o d ev ices. For ex amp le, a –3 d B loss indicat es a 5 0 p er cent loss of pow er , and a + 3 d B r ead ing is a d oubling of pow er . The r ule of t hum b is t hat 10 dB indicat es an in cr ease ( or loss) by a fact or of 1 0. Lik ew ise, 2 0 d B ind icat es an incr ease ( or loss) of a fact or of 1 00, and 30 d B indicat es an increase ( or loss) of a fact or of 10 00. Because an t en nas an d ot h er RF d ev ices/ sy st em s com mon ly hav e pow er gains or losses on t he or d er of m ag nit ude of 4, dB is a m or e easily u sed ex pr ession. •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

dBi .

By Cisco Systems, Inc.

dB r ef er encing an isot r opic an t enna ( hence t he " i" ) t h at is t h eor et ically p er fect in t er ms of et r icPress pat t er ns of r adiat ion. Real- w or ld ant ennas do n ot p er f orm w it h ev en nom inal Pub sym lish er:mCisco am ount s of sy m m et ry , b ut t his eff ect is generally u sed t o t h e syst em designer 's Pub Dat e: Sep tem ber 1 1, 2 003 adv ant ag e. I SBN: 1- 58 705 -1 19 -2

Pages: 11 28

dBm . dB r ef er encing 1 milliw at t . 0 dBm is defined as 1 MW at 1 k Hz of fr equ en cy at 60 0 oh m s of im pedance. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. dBW .Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . dB r ef er encing 1 wat t . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age de m odul at or . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . A d ev ice for assemb lin g sign als aft er t h ey hav e been r eceiv ed by an an t enna. A I n t ern dem et w or odulat k in g Tech or is nologies t yp ically Hand t h e fir book st m, ajor Fourdevice t h Ed it dow ion , nisstar eam com pr f rom ehensive an antrefer ennaence r eceiv t hat ing enables syst net em w or , and kin gitpex r ofessionals ist s on t he tbolock un derst d iagand ram an befor d imeplem v ar iou enst cont Ciscoem dev porices. ar y int Theercor netrwespon ork ing ding t echnologies. dev ice on Mast t h eert rtansm he t erission m s, con side cepoft s,a tsyst echn em ologies, is a mod an dulat devices or . used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all EI . kin g p rof essionals, r egar dless of ex pert ise. netRP w or sot r aopic Rad Pow erding . An of ex LAN pr ession of t henpeterwfor orm ancep ar oft icu an lar antlyent hna ReaderEfsfect w illive obtI ain g reat eriat uned der st an and WAN k ing, e in a enprdot ir ect ion and r elatser ivevtices o the ce of aent t hal eort ech et ical ( isotinf r oporic) ant enna. is on har dw giv ar e, ocols, invperf olvor edman . Fu ndam nology mat ion is prThis ov ided exp ressed at tal s or d BW. RPserv is t he sum of t he ower sent t o tipt h eion ants,enn plu squest ant enn a b r oad r ang e of in intwegr sy st em s EI and ices, in clud ingpdet ailed descr revaiew ionsa gain. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease e ct rom cterum . prleodu ct iv itag y net an dicimspe pr ov eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The f ull r an ge of elect r om agnet ic ( sam e as m agnet ic) f r eq uencies, t h e su bset of w hich is used in com mer cial RF sy st em s. Com m ercial RF sy st ems are t yp ically classified in r ang es t hat include MF, HF, VHF, SHF, an d EHF. Milit ar y sy st em s t y pically include f r eq uencies out side t hese t yp es.

fi x ed w ir el ess. The t yp e of Cisco w ir eless in w hich neit her t he t r an sm it t er nor t he r eceiv er is mob ile. Cisco w ireless is alw ay s b road band w ir eless, w it h dat a r at es in ex cess of 1. 5 Mb ps.

• foot p ri nt .

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I nt e rn et The w or g k ing eogTe r aphic chnologie ar ea s H in a ndbook w hich, Four an ent th Edit it y ion is licensed

t o br oadcast it s signal.

By Cisco Systems, Inc.

er: Cisco Press fr eqPub uelish ncy re use. Pub Dat e: Sep tem ber 1 1, 2 003

On e of t he am en t al concep t s on w hich com m er cial w ir eless sy st ems are b ased . I t I SBN: 1- 58 705f und -1 19 -2 inv olves p art it ion in g an RF r adiat ing ar ea ( cell) in t o segm en t s. For Cisco pur poses, t his Pages: 11 28 m ean s t hat t he cell is b rok en in t o t h ree equ al seg ment s. One segm en t u ses a fr equency t hat is f ar en ough aw ay f r om t he f r eq uency in t he bor der ing seg ment t o pr ev ent int er fer en ce pr oblem s. Th e sam e f r eq uency is used at least t w o cells apar t f r om each ot her . This pr act ice let s cellular p r ovider s hav e m any t im es m or e cust om er s f or a g iven sit e license. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. ga in . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . The r at io of a signal' s out p ut amp lit u de t o it s inp ut am p lit u de. This r at io is t yp ically exp ressed in decib els. The higher t h e gain, t he b et t er t he ant enn a r eceiv es or t r ansmit s, New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP bu t also t h e m ore noise it includes. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . li cen se . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat The pw uror chased t o t ran sm w av es an over a plem BTA is pically en- w y ear enables net kin g p rr ight ofessionals t o it unRF derst and d im entty cont em given por ar yfor intaert net ork ing per iod. Th e license t igh t ly gov er ns t he d esign par am et er s of an RF sy st em and it s RF t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net wuse. ork ing licenses ar e ( t y pically ) pur chased f rom t he FCC on an auct ion b asis. Th e FCC pr ovides indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . licenses o en su comerpet it ion in ait yfr,ee m age, ark etopt ( altical h ough is g, not alw ay s y, Com plet e w it h tnew anre d umax pdatim edum chapt s on secur st or net wt his or k in scalabilit obv ious in how t he FCC m anages t h e auct ions) and sp ect r al eff iciency , w hich is anot her and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all w ay of sayin g ef ficient use of t h e RF spect r um . net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on LM S. r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions a bD r oad t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Local Mult ipoint Dist rib ut ion Ser v ice. A r elat iv ely low - pow er licen se for b road cast ing v oice, Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy v ideo, and dat a. Typ ically , t w o licen ses ar e g ran t ed in t hr ee fr equencies, each t o separ at e syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich ent it ies w it hin a BTA. Th ese licen ses ar e k now n as Block A and Block B licen ses. Block A pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease licenses oper at e f rom 27. 5 t o 2 8. 35 GHz, 2 9. 10 t o 29. 25 GHz, and 31. 0 75 t o 3 1. 225 GHz, pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient for a t ot al of 1. 159 MHz of ban dw idt h. Block B licenses operat e fr om 3 1. 00 t o 3 1. 07 5 GHz decisions for t h eir net w ork s. and 31 . 225 t o 31. 30 0 GHz, for a t ot al of 150 MHz of band w id t h. LMDS sy st ems hav e a t y pical m axim um t r ansmission r ang e of app rox im at ely 3 m iles, as opposed t o t he t r ansm ission ran ge of an MMD S syst em , w hich is t yp ically 25 m iles. Th is diff erence in r ange is pr imar ily a f un ct ion of ph ysics and FCC- allocat ed ou t put pow er r at es.

LO S. Lin e of sig ht . Ref er s t o t he fact t h at t h er e m u st be a clear , un obst r uct ed p at h bet w een t r ansm it t er s an d receiv ers. Th is is essent ial f or LMD S pr od uct s and enhan ces g en er al per for m ance in ev ery RF deploy m en t , com par ed t o par t ial or com plet ely obst ru ct ed dat a pat h s. The op posit e of LOS is non- line- of - sig ht ( NLOS) . •

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I nt e rn MM D et S.w or k ing

Te chnologie s H a ndbook , Four th Edit ion

By Cisco Systems, Inc.

Mu lt ichan nel Mu lt ip oin t D ist r ibu t ion Ser vice. As m any as 33 discr et e chann els ar e t r ansm it t ed in a p seud or andom or d er b et ween t he t r ansm it t ers and r eceiv er s. The FCC has Pub lish er: Cisco Press allocat ed t w o b ands of fr equencies for each BTA—2. 15 t o 2 . 161 GHz and 2. 5 t o 2 .6 86 GHz. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

m obil e w ir el e ss. Cisco does n ot pr ov ide m obile w ir eless comp onent s. I nst ead, it pr ovid es backb one dev ices such as a GGSN t h at supp or t m obile w ir eless infr ast r uct ur es. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. N LOS. Con cise ovof er-vsig iew t echn olog ies obst essen t ial n et k ing ofession als at all lev els, f rom Nonlinehts. of Also k now n as r uct edt opat h wor or pat hwpray. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP pa ra bol ic a nt e nn a. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age A d ish lik e ant en na t hat sends RF w av es in a highly f ocused m ann er . Su ch ant en nas Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . pr ov ide v er y lar ge p ow er gains an d ar e h ig hly eff icient . This ant enn a is t y pical of Cisco's U-gNI I , an d MMDSHand sy stbook ems,, bFour ut t his is itnot only available appr opr iat e I n t ern LMDS, et w or k in Tech nologies t h Ed iont,he is a comdesign pr ehensive referor ence t hat for t hose f requ en cies. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, pa t h loss. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w orThe kin gp ow p rof egar dless of RF ex pert eressionals, loss t h at roccur s w hen w avise. es are t ran smit t ed t hr oug h t he air . This loss occu r s becau se t he at m osph er e f ilt er s t he sig nal. Cer t ain elect r om agn et ic fr eq uencies Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e ( v er y h igh and noncom m er cial) ar e com plet ely b lock ed or f ilt er ed by t h e at m osp here. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag em is ult also extnt end poi nt - t oipoi . ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools gu id elines f or opt syst per of forrm ance ws ill incr ease P2MP. Generally r efer sand t o t he com mu nicat ionimb izing et w een a em ser ies eceiver and pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient t r ansm it t er s t o a cent r al locat ion. Cisco P2MP is t yp ically set up in t hr ee seg ment s to decisions for t h eir net w ork s. enable f r eq uency r eu se. Cisco of fer s MMDS, U- NI I , and LMDS sy st em s in P2MP.

poi nt - t o- poi nt .

P2P. Has a h ig her ban dw idt h t han P2MP because, am ong ot her t h in gs, it h as less ov er head t o man age t h e dat a pat hs, an d only one r eceiv er ex ist s per t r ansm it t er. Cisco off er s MMD S, U- NI I , an d LMDS sy st ems in P2 P.

RF. • •

of Content s Rad io frTable equency . Gener ally ref er s t o w ireless com m unicat ions w it h f requ en cies below 3 00 I ndex GHz.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

TD MA . Pub lish er:

Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

Tim e div ision m ult iplex access. A t echniqu e for sp lit t in g t ran sm ission s int o t ime slot s, 58 ables 705 -1 19a-2gr eat er nu mb er of user s f or a g iven fr equency . A com m only used wI SBN: hich1-en Pages: 11 28e, as opposed t o CDMA. t echniqu

U-NI I . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Unlicensed Nat ion al I nf orm at ion I nfr ast r uct ur e. Cisco of fers a w ir eless pr oduct for t his in essent ial an d cu t t ing- edg e t ech nologies. t he 5. 7 GHz f requ en cy . Th is fr equency d oes n ot r equir e t h e use or p ur ch ase of a sit e license, bu t , as w it h all elect r onic d ev ices sold com m er cially, it does r equir e r egist rat ion w it hcise t heovFCC. NI sI is t er molog coined b y feder s t oprdescr ibe cit s' and Con er v iew of at echn ies essen t ial al t o rnegulat et woror k ing ofession alsizen at all lev els, f rom bu sin esses' access t o infor m at ion. Equiv alen t t o t he t er m " in for m at ion sup er h ig hw ay ," it nov ice t o ex pert . does n ot describe syst em ar chit ect u r e or t opology . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age W ir el ess Access P rot ocol. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . A lan guag e used f or w r it in g web pag es t hat u ses f ar less over head, w hich m akes it I n t ern pr et w efer or kable in g Tech for wnologies ir eless access Hand book t o t he , Four I n t er t hn Ed et .itWAP's ion , is cor a com r espon pr ehensive ding OS refer w as ence cr eat ted hatb y enables 3COM net wfor or kin it sgPalm p r ofessionals Pilot . Nokia t o un recen derst t lyand adopt an dedimt he plem Palm en t OS cont f or emitpor s war eby capab int er net le wcellular ork ing t echnologies. ph one. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 21. Digital Subscriber Line Obj e ct i ve s • •

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I dent if y and discu ss diff er ent t y pes of digit al su bscr iber line ( D SL) t echn ologies. I ndex

I nt e rn Discuss et w or k ingt he Te chnologie H a ndbook Editnologies. ion b en ef it ss of using x, Four DSLtht ech By Cisco Systems, Inc.

Ex plain how ASD L w or k s. Pub lish er: Cisco Press

Ex plain t he b asic con cept s of sign alin g and mod ulat ion.

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Discuss addit ion al DSL t ech nologies ( SDSL, HDSL, HD SL- 2, G. SHDSL, I DSL, and VDSL) . Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction Digit al Sub scr ib er Line ( DSL) t echn olog y is a m od em t echn ology t hat uses exist ing t w ist ed - pair t elep hone lines t o t r anspor t high- b andw idt h d at a, such as m ult im ed ia and v id eo, t o ser vice subscr ib er s. The t er m x DSL cov ers a nu mb er of sim ilar y et comp et in g f or m s of DSL t ech nologies, •includin g AD SL, TableSDSL, of Content s HDSL, HDSL- 2 , G. SHDL, I D SL, an d VD SL. x DSL is dr aw ing sig nificant •at t ent ion fr om I ndex im plem en t ers and ser v ice p rov ider s because it pr om ises t o deliver h ighIban nt e rn w or ing a Terchnologie s isper H a ndbook Four th Editw ion dwetidt hkdat at es t o d sed ,locat ions it h relat iv ely sm all chang es t o t h e ex ist ing t elco infCisco rast r uct ur e. Inc. By Systems, x DSL ser v ices ar e dedicat ed, p oin t - t o- poin t , pu blic net w or k access over t w ist ed- pair cop per w ire Pub lish er: Cisco Press on t he local loop ( last m ile) bet w een a net w ork ser vice pr ov ider' s ( NSP) cent r al office an d t h e 1, 2 003 custPub omDat er e:sitSep e, tem or ber on 1local loops cr eat ed eit her int r ab uilding or int r acam pus. Cur rent ly , m ost D SL I SBN: 158 705 -1 19 -2 main ly deliv ered t o resident ial cust om er s. Th is ch apt er focu s m ain ly on deploy m en t s ar e ADSL, 11 28 defin inPages: g ADSL.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Asymmetric Digital Subscriber Line Asym m et r ic Digit al Su bscr iber Lin e ( ADSL) t ech nology is asy m met r ic. I t allow s m or e band w id t h dow n st r eam —fr om an NSP's cent r al off ice t o t he cust om er sit e—t han upst r eam fr om t he subscr ib er t o t h e cen t ral off ice. Th is asy m m et r y , com bined wit h alw ay s- on access ( w h ich •elim inat es call Table Content s setof up) , m akes ADSL ideal f or I nt er net / int r anet sur f ing, v ideo- on- d em an d, an d •r em ot e LAN access. I ndex User s of t hese app licat ions t yp ically dow n load m uch m ore in for m at ion t han It hey nt e rnsend. et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

ADSL t r ansm it s m ore t han 6 Mbps t o a su bscriber an d as m uch as 640 Kbp s m ore in bot h dir ect ion s ( show n in Figur e 21 - 1) . Su ch r at es exp and ex ist ing access cap acit y by a fact or of 50 Pub lish er: Cisco Press or m or e w it hout new cabling . ADSL can lit er ally t r ansfor m t h e ex ist ing pub lic in for m at ion Pub Dat e: Sep tem ber 1 1, 2 003 net w or k fr om on e limit ed t o v oice, t ex t , and low - r esolu t ion gr aphics t o a pow er fu l, ubiqu it ous 1- 58 syst emI SBN: capab le705 of-1br19in-2ging m ult im ed ia, including f ull- m ot ion v ideo, t o ev er y hom e in t he com ing y ear s.Pages: 11 28

Figu r e 2 1 -1 . Th e Com pon en t s of a n ADSL Ne t w or k I ncl ud e a Te lco a nd CPE The u pdat ed edit ion of t he b est - selling all- in-aone net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. ADSL w ill play a cr ucial r ole ov er t he n ex t decad e or m or e as t elep hone com pan ies ent er n ew m ar ket ss w f orill deliver m at v ideo m u ltand im edia f ornm oadban w ill Reader obt ain ing a g infor reat er union derin st an dingan ofd LAN WAN etat w s. or kNew ing, br p ar t icu lardlycabling the thar ak edwdecades t o r each all pr osp ect iv e subscrib er s. Success of t h ese n ew ser v ices depend s on ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on raeachin as man subscrib erstsem as sp and ossible ur ingint he y ears. By ipt br in ging m ov ies, b r oadgr ang e ofyint egr al sy servdices, cludf irst ing few det ailed descr ion s, rev iew quest ions tt elev ision , v ideo cat alogs, r em ot e CDROMs, corp orat e LANs, and t he I n t ern et int o hom es and o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . sm all businesses, ADSL w ill m ake t hese mar k et s viab le and pr ofit ab le for t elephon e com Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacyp anies and apps,licat ion in supp s ealike. syst em pr ovid g a lier m or r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. ADSL Capabilities An ADSL cir cuit con nect s an AD SL m od em on each en d of a t w ist ed- pair t elep hone line, cr eat in g t hr ee inf orm at ion chann els: a high - speed dow n st r eam chann el, a m edium - speed du plex chann el, an d a basic t elep hone ser vice chan nel. The basic t elephone ser vice chan nel is split of f fr om t he dig it al m odem by f ilt er s, t h us gu ar ant eeing u nint er ru pt ed basic t eleph one serv ice, ev en

if ADSL fails. The h igh- speed ch annel r ang es f r om 1. 5 t o 9 Mbps, and d uplex r at es ran ge f rom 16 t o 640 Kbp s. Each ch annel can be sub mu lt iplex ed t o f orm mu lt iple low er - r at e chan nels. I n ADSL net w ork s, t he filt ers are r efer r ed t o as Plain Old Telep hone Sy st em Split t er s , or POTS Split t er s. Th ey f un ct ion as b and- p ass filt er s f or t w o dist in ct f requ en cy ran ges, abov e 15 KHz, and below 1 5 KHz. Their pur pose is t o effect iv ely allow f or t he coex ist ence of bot h t he low er fr equ en cy v oice and t he higher - fr equency m odu lat ed d at a signal on t he sam e t r ansmission line. This r equir es POTS sp lit t er s, or f ilt er s, at bot h t he AD SL cust om er sit e and at t he serv ice • Table of Content s pr ov ider' s cen t r al off ice. •

I ndex

IADSL nt e rn et or k ingsTe s Haa ndbook , Four th ent Edit ion mwodem prchnologie ov id e dat r at es con sist wit h

Nor t h Am er ican T1 1 .5 44 Mbp s and Eu rop ean h ier ar chies ( see Figur e 21 - 2) , an d can be p ur chased w it h var ious sp eed r anges an d capab ilit ies. The m inim um con figu rat ion pr ov ides 1. 5 or 2. 0 Mb ps dow n st r eam and a 16 - Pub Kbps duplex chan nel; ot her s pr ov ide r at es of 6. 1 Mbp s and 64 Kbp s for duplex . Pr oduct s w it h lish er: Cisco Press dowPub n stDat r eam r at es up t o 8 Mbps an d duplex r at es up t o 640 Kbp s ar e available t oday . ADSL e: Sep tem ber 1 1, 2 003 m odem s accom m odat e Asy nchr onou s Tr ansfer Mode ( ATM) t ran sp ort w it h var iable r at es and I SBN: 1- 58 705 -1 19 -2 com pensat ion f or ATM over head, as well as I P pr ot ocols. By E1 Cisco 2. 0 48 Systems, Mbp s digit Inc. al

Pages: 11 28

Figu r e 2 1 -2 . Th is Cha r t Show s t h e Sp ee ds f or D ow n st r ea m Be ar e r a nd Du pl ex Be ar e r Cha n ne ls The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Dow nst r eam dat a r at es depend on a nu m ber of fact or s, including t h e len gt h of t he copp er lin e, it s w ir e gaug e, t he p resen ce of br idged t aps, and cr oss- coup led int er fer en ce. Lin e at t enuat ion incr eases w it h lin e len gt h and fr equency , and d ecr eases as w ir e diam et er in cr eases. I gn orin g br idg ed t aps, AD SL p er f orm s as sh ow n in Table 2 1- 1.

Tab le 2 1 - 1 . Cla im e d AD SL Phy si ca l- M edi a Per f or m an ce D a t a Ra t e ( M bps)

W ir e Ga uge ( AW G)

D ist a nce ( fe e t )

W ir e Siz e (mm)

D ist a nce ( km )

18 ,0 00

0. 5

5. 5

26

15 ,0 00

0. 4

4. 6

24

12 ,0 00

0. 5

3. 7

26

90 00

0. 4

2. 7

• 1. 5 or 2

24 s Table of Content

•

I ndex

1. 5 or 2

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

6.Cisco 1 By Systems, Inc. 6. 1 Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 1- 58 -1 19r-2 Tw o ofI SBN: the m ost705 dest uct ive im pair m ent s in a D SL local loop env ir onm ent ar e br idged t aps an d Pages: 11 28 load coils.

Abr idged t ap is any por t ion of a loop t hat is not in t he dir ect t alk ing pat h bet w een t h e CO and t he ser vice user 's t er m inat ing equipm ent and t hat is un t er m inat ed. A br idg ed t ap m ay be an un used cable p air con nect ed at an in t er m ediat e point or an ext en sion of t he cir cuit b ey ond t h e ser user locat m entalls, such as net halft aps, t s, or opens, w illcover cause Thev ice u pdat ed' sedit ionion of. tLine he b im estp- air selling in- one w ork ingshor r ef erence p rov ides age of ressent ef lect ions, w h ich degr ades t h e r each, sig nal qu alit y, and ach iev able d at a r at e. ial an d cu t t ing- edg e t ech nologies. Load coils ar e used t o m odify t he elect r ical ch aract er ist ics of t h e local loop , allow in g bet t er qu alitCon y voicer ansm over ex t ten ances ypofession ically gr als eat er han , 000 cise fr ovequency er v iew s tof t echnission olog ies essen ialded t o ndist et wor k ing( tpr at tall lev18 els, f rom feet ) .nov I n ice t hist o exex t endedpert . d ist an ce scenar io, loading coils ar e p laced ev er y 6, 000 f eet on t he line. Load coils ar e usually 88 m illihenr y ( m H) indu ct or s in st alled in cable splice cases or j unct ion box es. Thechapt load er coils sign if ican t ly im t het ant 3 k Hz qu alit y (VoI fr equency r esp onse) of long New s include cov erag e pr ofove im por t opics like P and EAP t elep hone cables, bu t eff ect iv ely elim inat e t h e abilit y of t he cab le t o pass D SL f r eq uencies. Load Cov erag e of cut t ing edge echn lik e opt n etance wor kof ingt he and st or coils aff ect DSL fr equencies by talt erinologies g t he ind uct iveical r eact t ran smage ission line. Cisco Syies st ems, ldwt oide leader in net or king n ett o. 95 per cent of Alt houAut ghhtored he mby easu r e var fr omwt or elco t elco, t hese capwabilit iesf or cant he covI nert erup a loop plan t , depend in g on t he desired dat a rat e. Cust om er s b ey ond t h ese d ist an ces can be t ern et wwor g Tech nologies book Four t h Ed sy it ion , iss.a As com ehensive refer t hate rI neached it hk infiber - based d ig it Hand al loop car,r ier ( DLC) st em t hpr ese DLC sy st em sence b ecom enables net w or g p r ofessionals un panies derst and im plem en t cont por ar y int erinnet ork iv ing com mer cially avkin ailable, t eleph onet ocom cananofdfer v ir t ually ub iqem uit ous access aw relat ely t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing shor t t im e. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Comyplet e w it hions newenv an ision d u pdat s on y , com st orpr age, optvical netAs w or in g, tscalabilit y, Man applicat ed fed or chapt ADSLerinv olv esecur d ig itital essed ideo. a krealim e signal, and al speed, is book is alink com plet d ku-patror e r ef er tence t heurt op t hat are fessen ialdat t o aall digit vid eot hcan not use - or n eet an wor levt oel der con rol prt ooced es ics com m only ound tin net wmu or kin g pion rofsessionals, egar dless ise. s incor por at e f orw ar d- er r or corr ect ion t h at com nicat syst em s. rTheref ore, of ADex SLpert m odem dr am at ically r educes er ror s caused b y im pulse noise. Er r or corr ect ion on a sy m bol- by - sym b ol Reader s w rilleduces obt ainerar gorreat er un der an ding ofs LAN WAN ninett ow aorlin k ing, p ar icu lar ly t h es of basis also s caused b y stcon t inuou noiseand coupled e. Tw o tcom ponent har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov on g for w ar d er r or cor rect ion are Reed- Solom on Codin g an d Byt e I n t er leaving . Reed Solom onided Coidin a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions emb ed s ov er head dat a bit s in t he for w ard d ir ect ion, pr ov iding t he receiv ing end w it h enou gh tinf o orm en suatreion con comp r ehcorr en sion and r etwenit thout ion, and ad dit ional r ces f or fu rt her udy . in g t ocept det ect and ect err or s, t h e need f or r etr resou an sm ission. Byt e I n st t erleav Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy t ak es t he t r ansm it t ed dat a st r eam and r e- ord er s it in t he t im e dom ain in or der t o m it igat e t h e syst emofs, sh prort ovid in gataion m or e rulse ealist ic pict e of eff ect - dur imp noise efur fect s. t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ADSL Technology

ADSL depend s on adv anced dig it al sig nal p r ocessin g an d cr eat ive alg orit h ms t o squ eeze so m uch inf orm at ion t hr oug h t w ist ed- p air t eleph one lines. I n ad dit ion, m an y adv ances hav e been r eq uir ed in t r ansfor m er s, an alog f ilt er s, and analog/ digit al ( A/ D ) conv ert er s. Lon g t elephon e

lines m ay at t enuat e sig nals at 1 MHz ( t he out er edge of t he ban d u sed by AD SL) by as m uch as 90 dB, for cin g analog sect ions of ADSL m odem s t o wor k v ery har d t o r ealize lar ge d yn am ic r anges, sep ar at e chann els, and m aint ain low noise f ig ur es. On t he out side, AD SL look s simp le—t r an sp arent syn ch ron ous d at a p ip es at v ar iou s dat a r at es over or dinar y t elephon e lines. The in sid e, w h er e all t he t r ansist ors wor k , is a m ir acle of m odern t echnology . Figur e 21 - 3 display s t he AD SL t ran sceiver –net w or k end. • •

Table of Content s I ndex

Figu r e 2 1 -3 . Th is Di ag r am Pr ov id es a n Ov e r vi ew of t he D ev ice s t h at M a ke U p t he ADSL Tr a nsce iv er - Ne t w or k En d of t he Topology

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age To cr eat e m ult iple chan nels, AD SL m odem s div ide t h e av ailab le band wid t h of a t elep hone line in one ofAut t wo w ays: equency div ision ultide iplexing echo n in Figur e h ored by frCisco Sy st- ems, w ormldw leader( FDM) in netor w or kingcancellat f or t he Iion, n t er as n etshow . 21 - 4. FDM assign s one b and for upst r eam dat a and anot h er band for dow nst r eam dat a. The dow n stetr w eam pat is t h en d iv ided bybook t im ediv ision intpr o ehensive one or mor e hence igh- speed I n t ern or k in g hTech nologies Hand , Four t h Edmitult ioniplexing , is a com refer t hat chann elsnet anwd or one or e low - sp eed chann r eamenpat h isem also iplex ed w intork o ing enables kin or g pm r ofessionals t o un derstels. and The an dupst im plem t cont porm arult y int er net corr espond in gMast low -er speed annels. Echo cellat ion assigns t he u pst reamin btand he t echnologies. t he t ch er m s, con cep t s,can t echn ologies, an d devices used odayt 'os ov neterwlap ork ting dow , and sept oarat es por t heat t we oint byerm eans of local echolog o cancellat a t echniq ue irwonm ell kn ow. n indunststryr eam . Lear n how incor net w or kin g t echn ies in t o ion, a LAN/ WAN env ent in V.3 2 and 4 mod Wited h eit her er t ech niqu e, AD lit s off a ical 4 - k Hz f orscalabilit basic y, Com plet e w itV.3 h new anem d us. pdat chapt s on secur it y SL , stsp or age, opt net rweg orion k in g, tand elepspeed, hone ser at tis heaDC end hed band . d at e r ef er ence t o t he t op ics t hat are essen t ial t o all t h vice is book com pletofe tan u p- t onet w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and serFigu v ices rinv ndam al ce t ech nology e olv 2 1ed -4. .FuEch o ent Can lla t i on inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

•

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figur e 21 - 4 d ep ict s echo cancellat ion. Tran sm it t ing an d r eceiv ing in for m at ion usin g t he sam e fr equ en cy spect r um cr eat es in t er f er ence w it hin t he sing le loop sy st em it self. Th is int er ference dif fer s fr om cr osst alk b ecause t h e off en ding t r ansm it w av ef or m is k now n t o t h e r eceiver an d can eff ect iv ely b e subt r act ed f r om t he at t en uat ed receiv e signals. Elim inat ing t h e eff ect s of t h e The u pdat of ttoheasb est - selling all- innet w ork ing r ef erence p rov ides cover age of t r ansm it t eredisedit r ef ion er r ed echo cancellat ionone . essent ial an d cu t t ing- edg e t ech nologies. An ADSL m odem or ganizes t he aggr egat e d at a st r eam cr eat ed by m ult iplexin g d ow nst r eam chann els, d uplex chann els, and m aint enan ce chan nels t oget her int o block s, and it at t aches an ov er v iewt os of t echn ologThe ies essen o n etcor wor k ing ofession at all err or Con cor rcise ect ion code each block. r eceivt ial er tt hen r ect s erprr ors t hat als occur durlev ingels, f rom nov ice t o ex pert . t r ansm ission, u p t o t h e lim it s im plied by t he cod e and t he block leng t h. At t he user ' s opt ion, t he un it also can cr eat e super blocks by int er leav ing dat a w it hin su bblock s; t his allow s t h e r eceiv er t o New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP corr ect an y com b in at ion of er r ors wit h in a specif ic sp an of b it s. This, in t ur n, allow s f or effect iv e t r ansm ission bot h tdat and vt id eo ologies sig nals. lik e opt ical n et wor k ing and st or age Cov erag of e of cut inga edge echn Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Signaling and Modulation This sect ion includ es t he f ollow ing :

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CAP andTable DMT of Modu Content lats ed ADSL I ndex

St and ard s and I nt e rn ADSL et w or k ing Te chnologie s HAssociat a ndbook ,ions Four th Edit ion By Cisco Systems, Inc.

CAP and DMT Pub lish er: Cisco PressModulated ADSL Pub Dat e: Sep tem ber 1 1, 2 003

DMT anI SBN: d CAP ar705 e -1 line1- 58 19 -2coding m et hods for m odu lat ing t he elect r ical signals sent over t h e cop per w ire in t h e local loop. Car r ierless Amp lit ude an d Phase ( CAP) is a com mon line- coding m et hod. Pages: 11 28 CAP is a w ell- und er st ood t echn ology because of it s similar it y w it h QAM. Alt h ough CAP is w ellun derst ood and r elat iv ely inexp en siv e, some ar g ue t hat it is diff icu lt t o scale because it is a single- carr ier m odulat ion t ech nique and is suscept ib le t o nar r ow ban d int er f er ence. Discr et e Mu lt i- Ton e ( DMT) uses m ult iple car rier s. At t h is point , DMT is cap able of m ore sp eed t han CAP. This is on e r eason t hat t he ANSI com m it t ee T1E1 . 4 accor ded it st andar ds st at us in docum ent The u pdat T1. 41 3. ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. This st an dar d calls for 256 sub bands of 4 k Hz each, t hereby occup yin g 1 .0 24MHz. Each su bban d can be m odulat ed w it h QAM 6 4 for clean sub band s, dow n t o QPSK. I f each of t he subb ands can ConQAMcise ov v iewulat s ofion, t echn olog iesfor essen t o n et wor ingt spr6.ofession all ret levur els, f rom supp ort 64ermod t hen t he w ar dt ial ch annel sup kpor 1 Mb ps.als Onatt he n pat h nov ice t o ex pert . ar e 32 subb ands, w it h a p ot ent ial f or 1. 5 Mbp s. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

CAP Cov anderag DMT e ofCompared cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age ored by Sy st ems, or ldw idea leader in net w or D king orat he I niplet er n car et . r ier t ech nique CAP isAut a hsinglecarCisco rier t echniqu e tw hat uses w ide p assb and. MT fis m ult t hat uses m any n arr ow ban d chan nels. The t w o hav e a n um ber of engineerin g d iff er ences, ev en It hou n t ern et wult orim k inatgely Tech Hand book t h Ed is w a or com pr ehensive refer pr ence t hat . gh, , t hnologies ey can off er sim ilar, Four serv ice t o itt ion h e ,net k layer s discussed eviously enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Adaptive Equalization Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Adap t ivkin e equalizer s ar e amr egar p lif ierdless s t h at e frise. equency r esp onse t o com pensat e f or at t enu at ion net w or g p rof essionals, of shap ex pert and ph ase er r or . Adapt iv e equ alizat ion r equir es t hat t he m odem s learn line char act erist ics and do so by send in gain pra obes and g an at ding t he ret n signals. Then et eqwualizer now Reader sw ill obt g reat er lookin un der st of ur LAN and WAN or k ing,t hen p ar tkicu larslyh tow h e it mu st am t o g et and a n ice, lat f requ ened cy. response. The eat er t h einf dyor nam r ange, t he m oron e har plify dw arsign e, prals ot ocols, ser vfices inv olv Fu ndam ent al t gr ech nology maticion is pr ov ided com plex r tang he equalizat ion. ADSL 5 0ices, d B of dy nam r ang e, descr com plicat ing t ive a b r oad e of int egr al sy st emrequ s andires serv in clud ingicdet ailed ipt ion s, adap rev iew quest ions equalizat w it h r ecent adv ances it aland sig nal p rocessing ( nrum h as t o en su reion. con Only cept comp eh en sion and r etinendig t ion, ad dit ional r esou cesber f or cr fuunching rt her st)udy . it becom e epossib le ext t o hend aveedsuch ion ninetrwor elatkively small packag Cov erag is also n ot equalizat only t o new ing concep t s, but ing. also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Adap t ive equ alizat ion r equir ed gu f oridCAP because char act er ist ics arance y sig nificant acr oss pr of essionals oper at e. isTools and elines f or opt noise im izing syst em per forvm w ill incrlyease tpr heodu fr equency t ive equ alizat n ot n eeded ecause, ncost oise ct iv it y anpassband d im pr ov .e Adap eff iciency, help ing ion t heisr eader m ake for morDeMT in t belligent - eff icient char act er ist ot w v ar y s. across an y giv en 4- k Hz su bban d. A maj or issu e in com par ing DMT decisions forics t h do eir nnet ork w it h CAP is d et er m ining t he p oint at w hich t he com plexit y of ad apt iv e equalizat ion su rp asses t h e com plex it y of DMT's m ult ip le Fou rier t r ansfor m calculat ions. Th is is det er m ined by f ur t her im plem ent at ion ex perience.

Power Consumption Alt hou gh DMT clear ly scales and does not need ad apt iv e equalizat ion, ot her fact or s m ust be considered. Fir st , w it h 256 chann els, D MT h as a d isadv ant age r eg ar ding pow er consum pt ion ( and , t her efor e, cost ) w hen com par ed w it h CAP. DMT has a high peak - t o- av er age pow er rat io because t he mu lt ip le car r iers can const r uct ively int er fer e t o y ield a st ron g sign al. DMT has h ig her com put at ion al r eq uir em ent s, r esu lt in g in m or e t r ansist ors t han t he t r an sceiv er chips. Nu mb er s •ar e m ost ly prTable ofar Content opr iet y at tshis p oint , b ut it is est im at ed t hat a single t ran sceiver w ill consum e 5 •W of pow er , Iev ndex en w it h fu r t her adv ances. Power consum p t ion is im por t an t because hu ndr eds or It hou nt e rnsan et wds or k(ing as Te car chnologie r ier s d ear s H alyndbook hop e), Four of tth r ansceiv Edit ion er s m igh t b e at t h e cen t r al off ice, or CEV. Th is w ould r eq uir e mu ch m or e heat dissipat ion t h an CAP r equir es. By Cisco Systems, Inc. Pub lish er: Cisco Press

Latency Pub Dat e:

Sep tem ber 1 1, 2 003

I SBN: 1- 58 705 -1 19 -2

Anot h er issue f or DMT is t h at lat encies are som ew hat h igher t h an w it h CAP ( 15) . Becau se each Pages: 11 28 subb and uses only 4 k Hz, no bit can t r avel f ast er t han per mit t ed by a QAM- 6 4. Th e t r ade- off bet w een t h rou ghp ut and lat en cy is a hist or ical one in dat a com m un icat ion s and has n orm ally been set t led in t h e mar k et place.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Speed essent ial an d cu t t ing- edg e t ech nologies. DMT app ear s t o hav e t he sp eed adv ant ag e over CAP. Because n arr ow car r ier s h ave r elat ively few eq ualizat or eolog aggr essiv e mt ial odulat t echniqu can beals used on lev each Con cise ion ov erpvrob iewlem s ofs,t m echn ies essen t o nion et wor k ing pres ofession at all els, f rom channnov el. ice For t CAP t o ach o ex pert . iev e com par able bit r at es, it m ig ht be necessar y t o use m ore b andw idt h, far beyon d 1 MHz. This cr eat es n ew pr oblems associat ed w it h high f requ en cies on w ires an d chapt er ssinclude e of imppor antcon t opics VoI P and EAP w ouldNew r ed uce CAP' cu r rent cov adverag ant ag e in owter su mplike t ion. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

ADSL Associations AutStandards h ored by Ciscoand Sy st ems, w or ldw ide leader in

net w or king f or t he I n t er n et .

I n t ern eter w or k inNat g Tech nologies Hand Four t h Ed it ionk,ing is aGrcom ehensive refer hated an The Am ican ional St andar ds I nbook st it u,t e ( ANSI ) Wor oupprT1E1. 4 r ecen t lyence apprtov enables net w or r ofessionals t o un and an dStim plemden t cont por intean er net w ork ing ADSL st andar d kin at g ratpes u p t o 6. 1 Mb ps derst ( DMT/ ANSI andar T1. 41 3)em . Th e ar Euyrop Technical t echnologies. t he t)ercont m s,r ibu contcep t s, ann t echn an3 dt odevices t oday ' s net w orks.ing St and ard s I nstMast it ut eer( ETSI ed an exologies, t o T1. 41 r eflect used Eu ropinean r equir ement indu41 st3rycu . Lear t o incorapor at e er net t echn ies in t o aend. LAN/I WAN onm ent . T1. rr entnlyhow em bodies sing le int t erm inalw or in tkin erfgace at tolog h e pr emises ssue Ienv I exirpands t he Com pletde tw new d ultpdat s onat secur it yemises , st or age, net wf or or kconf in g,igscalabilit y, st andar o itinhclu de an a mu iplexed edchapt in t erferace t h e pr end,opt p rical ot ocols ur at ion and andwspeed, t h is book a com anrov d uem p- t en o- dt s. at e r ef er ence t o t he t op ics t hat are essen t ial t o all net or k m anagem entis , an d ot hplet er eimp net w or kin g p rof essionals, r egar dless of ex pert ise. The ATM For um and t h e Digit al Audio- Visual Council ( DAVI C) hav e bot h r ecog nized AD SL as a Reader w ill obt a ission g reat erprun der stf an of edia. LAN and WAN n et w or k ing, p ar t icu lar ly t h e ph ysicals layer t r ain an sm ot ocol or ding UTP m har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Additional DSL Technologies This sect ion d iscusses t he f ollow ing DSL t echnologies:

•

SDSL

•

Table of Content s I ndex

I nt e rn HDSL et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

HDSL- 2

PubG. lish SHDSL er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

I SDN D ig it al Sub scr iber Line ( DSL) I SBN: 1- 58 705 -1 19 -2 Pages: VDSL

11 28

SDSL The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Sy m m et Subscriber Line ( SDSL) is a r at e- adapt iv e v er sion of HD SL an d, lik e HDSL, is essent ialr ic anDigit d cu al t t ingedg e t ech nologies. sym m et r ic. I t allow s eq ual ban dw idt h dow n st r eam f rom an NSP' s cen t r al off ice t o t h e cust om er sit e as up st ream f rom t he sub scr iber t o t he cent r al of fice. SDSL su ppor t s d at a on ly on a sin gle line and oes ov n ot t an alogolog calls. line coding an d can ansm it up 1. 54 Condcise er sup v iewpor s of t echn ies SDSL essen uses t ial t o2B1Q n et wor k ing pr ofession alst rat all lev els,t of rom Mb ps nov t o and a su. bscriber , or can be conf igur ed t o of fer a var iable r ang e of band w id t h up t o ice tfr o om ex pert 1. 45 Mb ps. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut hTE ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . NO I n t ern etow Binar or k in g Hand , Four t h Ed it ion , is at hat comcom pr ehensive ence yt hat Tw y , Tech One nologies Quat er nar y isbook a linecod ing t ech nique pr esses refer t w o binar bit s enables netawint or okinone g p trim ofessionals ane. d im plem en t cont em por ar y int er net w ork ing of dat e st at e ast oa un fouderst r- levand el cod t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, is a com e anbin d ued p- w t oe r ef ser on ence t o t he( wt op icselim t hatinare t ialup t o) ,all The sy m mett rhyist hbook at SDSL of ferplet s, com it d h at alway access hich at esessen call set net w or kin rof essionals, dless of pert m akes it agf p avor ab le WAN rtegar echnology f orexsm allise. t o m edium businesses an d b ran ch of fices, an d can be an aff or dable alt er nat iv e t o d ed icat ed leased lines an d Fr am e Relay ser v ices. Becau se Reader sw ill obt a gfreat der web st an ding of LAN et wnin or kging, p ar t icu ly t h e t r aff ic is sym m etain rical, ile t er ranun sf er, host ing , andand distWAN ance-nlear ap plicat ionlar s can har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on eff ect iv ely b e imp lem ent ed w it h SD SL. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy HDSL syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Or iginally edprby h igh biting - r atteheDSL ( HDSL) / T1/ E1 et echn olog ies h ave been pr odu ct iv itdev y anelop d im ov eBellcore, eff iciency, help r eader m ake mor in t elligent , cost - eff icient st andar d ized t hs. e Un it ed St at es and b y ETSI in Eu rop e. The ANSI st and ard cov er s decisions for tby h eirANSI net winork t w o- pair T1 t r ansm ission, w it h a dat a r at e of 784 Kbp s on each t w ist ed pair . ETSI st andar ds exist bot h for a t w o- pair E1 sy st em , wit h each p air carr y ing 116 8 Kb ps, and a t hr ee- p air E1 syst em , w it h 784 Kbp s on each t w ist ed pair . HDSL became popu lar becau se it is a bet t er w ay of pr ovisioning T1 or E1 ov er t w ist ed - pair

copper lines t h an t he long- used t echniqu e k now n as Alt er nat iv e Mar k I nv er sion ( AMI ) . HDSL uses less b andw idt h an d r equir es no r ep eat er s up t o t he CSA r ange. By u sin g ad apt iv e line equalizat ion and 2B1 Q m odu lat ion , HDSL t r ansm it s at 1. 544 Mb ps or 2 .0 48 Mbp s. AMI is a syn ch r onous clock- en cod in g t echn ique t h at u ses b ip olar pulses t o repr esent logical 1 v alues. I t is, t her ef or e, a t hr ee- lev el syst em . A logical 0 is r epr esent ed by no sym bol, and a logical 1 is r ep resen t ed b y pu lses of alt ern at ing polar it y. AMI coding w as used ex t ensively in fir st - gener at ion PCM n et wor k s, bu t suf fer s t he d raw b ack t hat a long r un of 0s p rod uces no • Table of Content s t r ansit ions in t he d at a st r eam and , t her ef or e, does not con t ain su ff icient t ran sit ion s t o g uar ant ee • I ndex lock of a DPLL. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

T1 Cisco By ser v Systems, ice can be Inc.in st alled in a day f or less t h an $1, 00 0 b y inst allin g HD SL m od em s at each end of t he lin e. I n st allat ion v ia AMI cost s m uch mor e an d t akes m or e t im e because of t he r eq uir entCisco t o ad d r epeat ers bet w een t he sub scr iber and t h e cen t ral off ice ( CO) . D ep en ding on Pub em lish er: Press t he Pub leng t h of t he line, t h e cost t o ad d repeat er s for AMI could be up t o $5, 0 00 and cou ld t ake Dat e: Sep tem ber 1 1, 2 003 m or e t han a w eek. HDSL is heavily used in cellu lar t eleph one b uildout s. Tr af fic f rom t he b ase I SBN: 1- 58 705 -1 19 -2 st at ion is backh auled t o t he CO usin g HD SL in m or e t han 50 p er cen t of inst allat ions. Cu r rent ly , Pages: 11 28 t he vast maj or it y of new T1 lines ar e pr ovisioned w it h HDSL. How ever , because of t he em bedd ed base of AMI , less t han 30 per cen t of ex ist ing T1 lines ar e pr ov isioned w it h HD SL. HDSL does hav e d raw b ack s. First , n o p rov ision ex ist s f or analog v oice b ecau se it uses t he v oice ban d. Second, AD SL ach iev es bet t er speed s t han HDSL because ADSL' s asym m et r y delib er at ely kThe eeps t he ed cr osst t he linalle. inSym m et ricwsy sting em s, as pHDSL, hav e crosst u pdat editalk ionatof one t he end b est of - selling one net ork r efsuch erence rov ides cover age alk of at bot h end essent ial s. an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing HDSL-2 nov ice t o ex pert .

pr ofession als at all lev els, f rom

HDSL-New 2 is chapt an emerersginclude in g st ancov darerag d and a pr er nat iv eVoI to P HDSL. Th e int ent ion is t o off er a e of imom porisin t antg talt opics like and EAP sym m et r ic ser vice at T1 sp eeds u sin g a single- w ir e p air r at her t han t w o pair s. This w ill en able it Cov erag cutert ing ologiesI t lik et wor ing and st or ageulat ion, shor t er t o operat e for eaoflarg potedge ent ialt echn au dience. w eill opt r eqical uiren mor e kag gr essive mod dist ances ( abou t 1 0, 000 f eet ) , an d bet t er phon e lines. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Mu ch of t he SDSL eq uipm ent in t h e m ark et t od ay uses t he 2 B1Q lin e code dev elop ed f or k in vgices TechDigit nologies Fourcom t h Ed it ion isave a com pr ehensive refer t hat at II nntt ern egr et atw edorSer al NetHand w or kbook . The, Bell pan ies, h in sist ed t hat u sin g tence his SDSL enables net werortkin p r ofessionals o un and an d im en t and contot em porser ar yvices int ert hat net warork speed s high hang 76 8 Kb ps can tcau sederst in t erf er ence w itplem h voice h er e ing t echnologies. erire t he m ts,hecon cepe t w s,irteechn ologies, an d devices used in t oday ' s net w ork ing off ered on copMast per w witt er h in sam b und le. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Combplet e w itad h van newt age an dof u pdat ed 2, chapt er swon it y , st or optas ical net w or k inbg, scalabilit y, The iggest HDSLw h ich as secur dev eloped t oage, ser ve a st and ard y w hich andferspeed, t h is book is a com pletld e an p- t oe rtef er ence o t he ed t opnot ics ttohat o all dif en t v endor s' eq uipm ent cou intderuoper atde,at is hat it is dtesign in tare er f eressen e w itthialotther net vwices. or kinHow g p rof essionals, dless pert ise.ing ser v ices only at 1. 5 Mbp s. ser ever , HDSL- 2r egar is f ull r at eofonexly, of fer Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on G.SHDSL a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . G. SHDSL st andar d s-ed b ased, mu ltt irat e ver sion HDSL2 ant s, d off s sy mm et rerical ser vice. The Cov erag e is is aalso ext end n ot only o new n et worof k ing concep buteralso t o old , legacy adv ant HDSL, worhich was ic developed serv e as a st d kby w hen ich ferent en ts vin endor s' syst emag s, eprof ovid in g a2 m e r ealist pict ur e oft ot he realw or ld andar n et w or ing virdif onm w hich equipm ent could er at e, is gu t h at it is desig nedimn izing ot t o syst int erem fer eper w itfor hm otance h er ser v ices. How ev er, pr of essionals operinatt erop e. Tools and id elines f or opt w ill incr ease t heodu HDSLd ov add on ly help ser ving icest he at r1. 5 Mbps. Mult irate einHDSL2 is par t- eff of icient I ssue 2 of pr ct iv it2y st anandar d im pr e resses eff iciency, eader m ake mor t elligent , cost t he st an dar ow net n as G. SHD decisions ford tkn h eir w ork s. SL, an d is r at if ied by t he I TU. G. SHDSL builds u pon t he benefit s of HDSL- 2 b y off er ing sy mm et r ical rat es of 2 .3 Mb ps.

ISDN Digital Subscriber Line

I SDN digit al su bscr iber line ( I DSL) is a cross b et ween I SD N and x DSL. I t is like I SDN in t hat it uses a sing le- w ir e pair t o t r ansm it fu ll- dup lex d at a at 128 Kbp s and at dist ances of up t o RRD r ange. Like I SDN, I D SL u ses a 2B1Q line code t o enable t r an sp arent oper at ion t hr ough t h e I SD N " U" int er face. Finally, t he u ser cont inu es t o u se ex ist in g CPE ( I SD N BRI t er m inal ad apt er s, br idg es, an d r out er s) t o m ake t he CO connect ions. The b ig d iff er ence is fr om t he car rier 's p oin t - of- view . Un lik e I SDN, I DSL d oes n ot conn ect t hr ou gh t he v oice sw it ch. A new p iece of dat a comm u nicat ion s equipm ent t erm inat es t h e I DSL • Table of Content s connect ion and sh ut s it off t o a r out er or dat a sw it ch. Th is is a k ey feat ur e b ecause t h e • I ndex ov er loading of cent r al of fice voice sw it ch es by dat a user s is a g row ing p rob lem f or t elcos. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By The Cisco lim Systems, it at ion ofInc. I D SL

is t hat t he cust om er no lon ger has access t o I SDN sign alin g or voice ser v ices. But for I n t ern et ser v ice p r ovider s, w ho do n ot p rov ide a pub lic voice ser v ice, I DSL is an int er est ing ay Press of u sing POTS dial ser vice t o offer h igher - sp eed I nt er net access, t ar get ing t he Pub lish er: w Cisco embPub ed Dat dede: base of m ore t han fiv e m illion I SDN u ser s as an init ial m ar ket . Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

VDSL

Very - High- Dat a- Rat e Digit al Subscr iber Lin e ( VDSL) t ran sm it s h igh- speed d at a ov er shor t r eaches of t w ist ed- pair cop per t eleph one lines, w it h a r ange of sp eeds d ep en ding on act ual line lengt . The ax imu r eam r at eallu nder considerat et w eenp5rov 1 and Mbpage s over The uhpdat edmedit ion m of dow t he nbst est - selling in- one net w orkion ing is r efberence ides55 cover of lines up t o 100 0 f eet ( 30 0 m ) in lengt h. Dow n st r eam speeds as low as 13 Mbp s ov er leng t hs essent ial an d cu t t ing- edg e t ech nologies. bey ond 400 0 feet ( 15 00 m ) ar e also com mon . Upst r eam rat es in early m od els w ill be asym m et r ic, j ust lik e ADSL, at speeds f r om 1. 6 t o 2 . 3 Mbps. Bot h dat a chann els w ill b e sep arat edcise in frov equency rom band s used f or basic t elep ser vice and I SDN, linels, g ser vice Con er v iew s fof t echn olog ies essen t ial t o n et hone wor k ing pr ofession als atenab all lev f rom pr ov iders t o tov erlay on exist ing ser v ices. Cu r rent ly , t h e t w o h ig h- speed chan nels ar e also nov ice o ex pertVDSL . sep arat ed in fr equency . As needs ar ise for higher - speed up st ream chan nels or sym m et ric r at es, chapt s include e of im por t ant VDSLNew syst em s meray need t o cov useerag echo cancellat ion . t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary ADSL t echnology is asy m m et r ic, allowin g m or e ban dw idt h f or dow nst r eam t han up st ream d at a flow . Th is asym m et ric t echn olog y comb ined w it h alw ays- on access m ak es AD SL id eal for u ser s w ho t yp ically d own load m uch m or e dat a t han t hey send. •

Table of Content s

•An ADSL m odem I ndex is connect ed t o bot h ends of a t w ist ed - pair t elephone lin e t o cr eat e t hr ee Iinf nt orm e rn etat w ion or k ing Te chnologie s H a ndbook Edit ion chann el, a m edium - speed du plex ch annel, an d chann els: a high - speed, Four dowthn st r eam a b asic t eleph one ser v ice ch annel. ADSL m odem s creat e m ult ip le ch annels by d ividin g t h e By Cisco Systems, Inc. av ailab le band w id t h of a t elep hone line using eit h er fr eq uency- division mu lt iplex ing ( FDM) or ech o cancellat ion . Bot h t ech niques split off a 4- k Hz r eg ion f or basic t elephon e ser v ice at t he D CPub lish er: Cisco Press end of t he b and. Pub Dat e: Sep tem ber 1 1, 2 003 SBN: 1- 58 705 -1 -2 bscr iber Lin e ( SDSL) pr ov ides var iable, sy mm et r ic, high- sp eed dat a Sy nchrIonous Digit al19Su com mu Pages: nicat11 ion 28 u p t o 1. 54 Mb ps. But SDSL doesn' t allow analog on t he sam e line, as AD SL d oes. SDSL uses 2B1 Q line codin g, a t ech nology em ployed in I SD N and T1 ser v ices. SDSL is a v iable bu sin ess opt ion b ecause of it s capab ilit y of t r an sm it t ing hig h- speed d at a ov er longer dist ances fr om t he CO and b ecause of it s ease of deploy ment m ade p ossible b y it s spect r al com pat ib ilit y .

High Bit - Rat e D SL ( HD SL) is a sy mm et r ic ver sion of DSL t h at u ses 2B1 Q lik e SDSL, but ov er The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t w o- w ir e pair s. HDSL is t ar get ed at business deploy ment because it of fer s f ull- rat e sy m m et r ical essent ial an d cu t t ing- edg e t ech nologies. 1. 5 Mbp s ser v ice. HDSL- 2 is a st and ard s- based v er sion of HD SL of fer ing sym m et rical 1 .5 Mb ps ser v ice lik e HDSL, but w it h a single t wist ed pair of w ires. HDSL is f ull- rat e and does not off er v ariabCon le rat es.ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom cise nov ice t o ex pert . G. SHDSL does of fer m ult ir at e ser v ice wit h sy mm et r ical sp eeds of up t o 2 .3 Mb ps. I SDN d igit al subscrNew ib er chapt lin e (er I DSL) is simcov ilarerag in m ay st ant t o I tSDN. imPary er ence is t h at I DSL is s include e any of imwpor opics The like pr VoI anddiff EAP alw ays on an d can r each speed s up t o 512 Kbp s w it h com pr ession. I D SL u ses 2 B1Q lin e coding and does n ot e sup an alog . On t h eologies ot her han I DSL allow at a com m unicat ions ov er Cov erag ofpor cuttt ing edge t echn lik ed,opt ical does n et wor k ingdand st or age longer d ist an ces t h an ot her DSL opt ion s ( up t o 26, 00 0 f eet ) and is considerab ly less ex pensiv e t han IAut SDN h ored ser vice, by Cisco in most Sy stcases. ems, wBecau or ldwse ideI DSL leader supinpor net t swexist or king ing f Ior SDN t heCPE, I n t eritn et mak . es it easy t o conv er t fr om I SDN t o I DSL. Ver y - High- D at a- Rat e D igit al Sub scr iber Lin e ( VDSL) t r ansm it s high I n t ern et w or k iner g Tech Hand t h Ed it ion , is a tcom ehensive ence t hat y is speed d at a ov sh or tnologies dist ances t hr book ou gh, tFour w ist edp air copper eleppr hone lin es. refer VDSL t echnolog enables netdef w or g pstr age, ofessionals t o ional un derst and an dis im plem enbef t cont por ar y st intandar er netdized. w ork ing st ill in t he inkin it ion b ut addit r esearch r eq uir ed oreem it can be t echnologies. Mast t he t er tm s, con cep t s, How t echn ologies, angh d devices inst oday s net w ork ing VSDL and ADSL ar er e similar echnolog ies. ever , alt hou VSDL t rused ansmit dat a ' at near ly 10 st ry . Lear t o incor por er net w orplex kin gt tr echn ies tin t o aology LAN/. WAN env ir onm ent . tindu im es t he r at enofhow ADSL, ADSL isat t heeint mor e com ansmolog ission echn Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

Nam e t he cu rr ent ver sion s of DSL t ech nology .

2:

I ndex ar e t he t w o- lin e coding m et h ods u sed for AD SL? What

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : Which By Cisco Systems, Inc. 4:

ver sion s of DSL off er sym m et rical serv ice?

What sym m et r ical v er sion of DSL off ers mu lt ir at e ser vice ov er a single p air of w ire?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 58 705f -1 -2 a 5 : 1-How ar19of

r each can I DSL ach iev e f rom t he CO?

Pages: 11 28

6:

What dow n st r eam and u pst ream r at es ar e pr op osed for VD SL?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • AD SL For um (w w w .ad sl. com / ) •

Table of Content s

•• Cisco DSL IDepot ndex (w w w .cisco. com / w arp / pu blic/ 7 79/ ser vp ro/ p rom ot ion s/ d sld ep ot / ) I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 22. Cable Access Technologies Obj e ct i ve s • •

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Under st and hy br id f iber coax ( HFC) n et w or k ing con cept s as a v iable d at a m edium . I ndex

I nt e rn Ietdent w or kifing Te chnologie H aize ndbook Four th Edit ion y and char actser dom, inan t HFC lim it at ions By Cisco I ntSystems, er face Specificat Inc. ions

associat ed w it h Dat a Over Cable Serv ice ( DOCSI S) dat a t r ansm ission.

Under st and t he ( D OCSI S) st and ar d f or dat a t r anspor t over Cab le Telev ision Sy st em ( CATV) .

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

I SBN: 1705iliar -1 19 -2 Becom e 58 f am w it h DOCSI S har dw ar e deploy m en t an d r esult ing capabilit ies. Pages: 11 28

Becom e aw ar e of f ut ur e ap plicat ion s of t he D OCSI S st and ard t o supp ort adv anced ser vices.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction Hist orically, CATV h as been a unid ir ect ion al m edium d esign ed t o car r y br oadcast an alog v ideo chann els t o t he max im um n um ber of cust om er s at t he low est p ossible cost . Since t he int r odu ct ion of CATV m ore t han 50 y ear s ag o, lit t le has chan ged b ey ond incr easing t h e num b er •of chann els sup Table Content poroft ed. Th es t ech nology t o pr ov id e high - m arg in , t w o- w ay serv ices r em ained •elusiv e t o t heI ndex op er at or . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Du ring Systems, t h e 19 90s, By Cisco Inc. w it h t he in t rod uct ion of direct b r oadcast sat ellit e ( D BS) and dig it al subscrib er line ( DSL) , t h e cab le oper at ors ex per ien ced a seriou s challen ge t o t heir ex ist ence by com pet ing t echnologies t hr eat ening t o er ode mar k et shar e of t heir single p rod uct . Pub lish er: Cisco Press

Dat e: ors Sep tem berk1et 1,ed 2 003 DBSPub operat m ar m or e ch oice an d bet t er qualit y ent er t ainm ent pr oduct t hr ough d ig it al I SBN: 158 705 -1 19 -2 t echnology , w her eas t he in cu mb en t local ex ch ange car r ier s ( I LEC) p r oposed t o off er a com binat Pages: ion11of 28 voice, v id eo, and dat a by m eans of DSL.

Fear ing loss of m ark et shar e an d t he need t o of fer adv anced ser vices t o r em ain econom ically v iable, key m ult iple sy st em operat or s ( MSOs) f orm ed t he Mult imedia Cable Net w or k Sy st em Par t ner s, Lt d. ( MCNS) , wit h t h e pur pose of d ef ining a p rod uct an d sy st em st andar d capable of pr ov iding dat a and fu t ur e ser v ices ov er CATV plant s. MCNS pr oposed a pack et - based ( I P) The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of solut ion in cont ent ion w it h a cell- b ased ( ATM) solu t ion p r omot ed by I EEE 802 .1 4. MCNS par t n er s essent ial an d cu t t ing- edg e t ech nologies. included Com cast Cab le Com mu nicat ions, Cox Comm u nicat ion s, Tele- Com m un icat ions I n c. , Tim e War ner Cab le, Med iaOne, Roger s Cab leSy st em s, an d Cable Telev ision Lab orat ories ( Cab leLabs) Con cise. ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . The D at a Over Cab le Ser v ice I n t er f ace Specif icat ion ( DOCSI S) 1. 0 st andar d t hat r esult ed fr om t he MCNS ef for ter wsasinclude unanimcov ously t edpor ast ant t he t Nor t h like Amer ican st and ard , and v en dor s New chapt eragaccep e of im opics VoI P and EAP agg ressiv ely int r oduced pr oduct s in com pliance w it h t h is st andar d. MSOs d ef ined u pgr ade and const rCov ucterag ion per ogr ams t o edge incr ease t he supp ort bandw h ofk ing t heirand plant s age an d t o pr ov ide t w oof cut t ing t echn ologies lik in e gopt ical nid ettwor st or w ay f unct ionalit y . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The D OCSI S 1 . 0 st and ar d p rescribes m ult iv endor in t er op er abilit y and p rom ot es a ret ail m odel I n t ern for t heetconsum w or k in gerTech 's d irect nologies p ur ch Hand ase book of a cable , Fourm t hodem Ed it ion ( CM) , is a of com choice. pr ehensive To ensurrefer e mence ult iv endor t hat enables int er operab net w ilitory ,kin CableLabs g p r ofessionals sub jectt os all un derst pr od uct ands an offdered im plem t o r igor en t ous conttem est por ing .arEq y uipm int er net entw ork ing t echnologies.p assing successfully Mast er all t het est t ersmws,illcon be cep CableLabs t s, t echnQualified ologies, an f ord headdevices endused Cable in Modem t oday ' s Ter net w mork in ating ing indu Sy st em st ry (. CMTS) Lear n ,how an d t CableLabs o incor por at Cer e int t if ied er net forw CM or kin devices. g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, To e, t het hDisOCSI S is 1 . 0a st andplet ar de is ing be ersalt osuccess, w itthhat deploy ment st ial now andd at speed, book com anpdrov u pt o-tdo at e raefuniv er ence t he t op ics are essen t o in all oper at ion wor ldw ide. net w or kin g p rof essionals, r egar dless of ex pert ise. Cab leLab conj and com m un itnies, recen t lyt icu defin ed t DOCSI S Reader s ws,illinobt ainunactgion reatwerit hunt he dervstendor an ding of user LAN and WAN et whas or k ing, p ar lar ly he 1. 1.dw Wit enh ancem s vt oices t heinv pr olv ot ocol, it ndam is nowent mal ore capnology able ofinf suppor in g is Voice er on har arhe,t he pr ot ocols, andent ser ed . Fu t ech or mattion pr ovOv ided Iantber net rPr ot ocol ( VoI P)aland secuices, rit y , in anclud d ising also p avin t he wipt ayion f ors, adv f ut uions re r oad ang e of int egr sy stadv em anced s and serv det ailedg descr revanced iew quest m ser v ices. t o ult enim sued re ia con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Evolution from One-Way Broadcast to Two-Way Hybrid Fiber Coax A CATV net w or k consist s of a head- end locat ion w here all incomin g sign als are receiv ed an d, •r eg ar dless ofTable Content t h eirofsour ce, sfr equency - div ision m ult iplexin g ( FDM) is ap plied , am plified, an d •t r ansm it t ed dow I ndex n st r eam f or d ist r ibut ion t o t he com plet e cable plan t . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Or iginal CATV n et w or k s, as show n in Figur e 22 - 1, w er e ex clusively one- w ay , comp rised of By Cisco Systems, Inc. div erse am plifier s in cascade t o comp en sat e for t h e int r insic sig nal loss of t h e coax ial cable in ser ies w it h t aps t o cou ple v ideo signal fr om t h e m ain t r un ks t o sub scr iber hom es v ia dr op cab les. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages:r11 Figu e 282 2 -1 . A Sim pl e, O n e- W ay V ide o Br oa dca st Topology U si ng Coa x ia l Cab li ng Excl usiv e ly

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . IBesid n t ernes et w or kginugnidir Techect nologies book Four t hcascad Ed it iones, is a com b ein ional, tHand he long am, plifier result ed pr inehensive a sy st emrefer w it hence h ight hat noise enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er w ning ork ing t hat w as inh er ent ly un r eliable an d f ailur e- p ron e, in ad dit ion t o b eing suscep t ible t o net lig ht tstechnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing r ik es and ing ress noise fr om for eig n r adio fr equency ( RF) sig nals. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . plet noise e w it hisnew u pdat edmchapt onersecur it y ,en sttor k in g, (scalabilit y, . ICom ngr ess unwan andt ed elect agn eter ic sen gy t hat er age, s t h eopt Hyical br id net - Fibweror Coax HFC) plant and rspeed, a com plet e an floor d u p-of t o-tdh at r ef er ence t o sy t he t op, ics t hatisare essen The esult oft htis h isbook is t oisr aise t he noise is et ran smission st em w hich m ean t t ot ial bet o a all net w or sy kinstgem. p rofThis essionals, dless ex pert closed causesr egar devices t oof t ran sm itise. at h ig her pow er levels t o ach iev e t he sam e per for m ance. Som e sou r ces of ing ress noise ar e un t er m inat ed t aps, loose connect ors and Reader w ill fobt ain a g reat er un fit t in gs,s and ault y equip ment . der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad angnificant e of intim egrpralovem sy st em and ices, in clud ingt he detint ailed The f ir st rsig en tst o t heserv CATV p lan t w as r odudescr ct ionipt ofion f ibs,er rev - opiew t ic quest ions tt o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . echnology an d t he ad vent of t he HFC plant ( see Figur e 22 - 2) . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ovreeeff helppl inge t HFC he r eader e inNt elligent Figu 2iciency, 2 -2 . Sim Di stmrake ibumor t ion et w or, kcost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Por t ions of t h e coaxial cable an d su ppor t ing am plificat ion elem en t s ar e r ep laced w it h m ult if iber I SBN: 1- om 58 705 19 -2 end or h ub locat ion . The ag gr eg at ed v ideo sign al is used t o m odu lat e a opt ic cab le fr a -1head Pages: 28 dow n st r eam11laser , w h ich t r ansm it s t he op t ical sig nal t o an opt ical nod e, wh ich , in t ur n, conv er t s t he sign al f rom an op t ical t o an elect r ical sig nal t h at can t hen be p rop agat ed dow nst r eam t o t h e ent ir e cust om er ser ving ar ea. I t can be r eadily seen t hat t he in t r oduct ion of t he f iber can signif ican t ly r ed uce t he n um ber of cascaded s con en t-ly im pr oving st em signalt o-ides n oise r at io ( SNR) The u pdatam ed plifier edit ion of tsequ he b est selling all- in-sy one netrweliabilit ork ing y, r eft he erence p rov cover age of of tessent he dow nst r eam vid eo sig nal, and pot en t ial syst em ban dw idt h. I n ad dit ion, t h is m akes t h e ial an d cu t t ing- edg e t ech nologies. syst em r eady f or t he n ex t st ep t o t w o- w ay oper at ion . As an add ed benef it , HFC r educes oper at ional an d m aint en ance cost s, an d im pr ov es t he im m unit y of t he syst em t o ingr ess noises. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Tw o- w ay ice oper ion is . ach iev ed b y t he ad dit ion of requ isit e u pst r eam amp lif ier s in t he amp lif ier nov t oat ex pert hou sin gs, t he ad dit ion of a nar r ow - ban d u pst r eam laser in t he op t ical node, a dedicat ed up st r eam iber ter o st hinclude e head cov en d, an de aof comp ible topt icallike r eceiv t o conv New fchapt erag im poratt ant opics VoIer P and EAPert any upst r eam inf orm at ion t o an elect r ical signal. Wh en all com pon en t s ar e in p lace, p rop er ret u rn pat h Cov cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age alignm enterag is reeqofuired. Aut h ored bying Cisco Sytst ems, w ort ldw ideaph leader in cable net w or king I n tgerreat n eter . r eliab ilit y , By m eans of add an op ical RI NG opogr y, t he n et w orfkoraft he for ds supp ort s gr eat er band wid t h w it h t h e cap abilit y t o t ran sp ort m or e infor m at ion, and is ready t o I n t ern et w inay g Tech book Edof it ion , isisit a ecom prpon ehensive refer t hat supp ort t woro-k w opernologies at ion byHand t h e sim ple, Four ad ditt hion requ com en t s, as illuence st rat ed in enables Figur e 22net - 3.w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h isr e book pletnced e an d uHFC p- t o- dNe at et w r efor er ence t hatogr are aph essen Figu 2 2 is -3a. com Adva k w tito ht he Rit op ngicsTop yt ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Net w ork rob ust ness, scalabilit y, and flexib ilit y is f ur t her im pr ov ed b y t he in t rod uct ion of t he Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom int er m ed iat e hub f rom wh ich adv anced ser v ices can u lt imat ely b e launched. nov ice t o ex pert . The HFC net w or k and t opog rap hy as ou t lined b ecom e t he basic building b lock s f or developing New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP access t r anspor t cap abilit ies n eeded by t h e MSOs t o com pet e in t he dy nam ic com m unicat ion env iron ment Cov erag. e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Limitations and Specifications of the HFC Plant The HFC net w or k has t h e pot ent ial t o of fer t r emend ous b andw idt h in t he d ow nst r eam or for w ar d dir ect ion f rom t he h ead end or hu b t o t h e cu st omer . Depend in g upon t he ex t ent of t he p lan t up gr ade, t he available b andw idt h could be as mu ch as f r om 54 t o 860 MHz. Dow nst r eam •chann el bandTable of Content s er m in ed b y t he ind ividu al count ry ' s vid eo br oadcast st and ard s. w id t hs ar e d et •

I ndex

IThe nt e rn orical k ing br Teoad chnologie s H a ndbook , Fourassignm th Edit ionent s lim it t h e upst r eam or r ever se dir ect ion fr om h et istwor cast video ch annel tBy heCisco cu stSystems, om er t oInc. t he spect r um b et w een 5 t o 42 MHz. Th is upst r eam spect ru m is fr equ en t ly host ile t o ret ur n - pat h connect ivit y d ue t o t he in gr ess of f oreign int er fer ing sig nals, su ch as h am r adio cit izen ban d ( CB) , am ong ot h er legit im at e RF em ission s. Pub lish er: Cisco Press

Pub2Dat Sepmm tem ber 1 1, 2 t003 Table 2- e: 1 su ar izes he specificat ions f or t he d ow nst ream d irect ion, an d Table 2 2- 2 I SBN: 158 705 -1 19 sum m arizes t h e sp ecif-2icat ions for t h e up st r eam dir ect ion . Pages: 11 28

A D OCSI S sy st em mu st pr ov ide gr eat er t han 99 p er cen t av ailabilit y w hen f or w ard ing 150 0- by t e pack et s at t h e r at e of at least 1 00 pack et s per second . To achiev e t hese cr it er ia, cer t ain CATV per for m ance specif icat ion s ar e m andat ed on bot h t he u pst r eam and dow nst r eam spect r um . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Tab le 2 2 - 1 . Dow nst r e am Ca ble Spe cif icat ions Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Assum es n om i na l an al og vi de o car ri er l ev e l ( pea k e nv el ope pow e r) in a 6 - MH z cha nne l w it h a ll New chapt er s include cov erag e of im por t ant pre t opics VoI P and EAP condi t ions senlike t concurr en t ly a nd re f er en ce d t o D ow nst re am Pa ra m et e r fr eq ue ncie s gr ea t e r t han 8 8 M H z Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age RF chan nel spacing ( BW) 6 MHz Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Tr ansit d elay , CMTS t o most Less t han or equ al t o 0. 800 m s I ndist t ern ant et wcust or kom in gerTech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing CNR in a 6- MHz ban Not t han 3 5 d Ban ( analog v ideo level) t echnologies. Mast er dt he t er m s, con cep t s,less t echn ologies, d devices used in t oday ' s net w ork ing indu ryio . Lear t o er incor poret atee intNot er net w ort han kin g3t5echn iest in a LAN/BW WAN env ir onm ent . C/ I st rat for tnothow al pow ( d iscr less d B olog w it hin het od esign Com e wband it h new d usig pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and plet br oad ingran ess nals) and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Com posit iplebeat d istror t iondless Not eatise. er t h an 50 dBc w it hin t he design BW net w or kin ge pt rrof essionals, egar of exgrpert for analog- m odu lat ed car rier s Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Com d- orand der ser distvor t ioninvNot gr. eat t h an it hin t inf he or design BW har dwposit ar e, eprsecon ot ocols, ices olv ed Fu er ndam ent50 al dBc t echw nology mat ion is pr ov ided on for analogm odu lat ed car rier s a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t oCren su mod re con cept r et gr eneat t ion, ional r cesdesign f or fu rt her st udy . ossulat ioncomp lev el r eh en sion andNot er and t h anad 40ditdBc w itr esou hin t he BW Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Amem plits, udpr e ovid rip ple 0. 5urdB hinrealt he wdesign BW syst in g a m or e r ealist ic pict e ofw tithe or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Gr oup delay r ipple in t he 75 ns w it h in t he design BW pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient spect ru m occu pied b y t he CMTS decisions for t h eir net w ork s.

Micr oreflect ions bou nd for dom inan t echo

10 dBc at less t han or equal t o 0 .5 m s 15 dBc at less t han or equal t o 1 .0 m s 20 dBc at less t han or equal t o 1 .5 m s 30 dBc at less t han or equal t o 1 .5 m s

• Car r ier humTable Content m odof ulat ion s • I ndex

Not gr eat er t h an 26 dBc ( 5 per cen t )

Bur stetnwoise Less t han I nt e rn or k ing Te chnologie s H a ndbook , Four th Edit ion2 5 By Cisco Systems, Inc.rn al Season al and diu

signal lev el

m s at a 1 0 Hz av er age rat e

8 dB

v ariat ion Pub lish er: Cisco Press

Signal lev el slope ( 50 t o 750 MHz)

16 dB

Pub Dat e: Sep tem ber 1 1, 2 003

Max imI SBN: um analog ideo 1- 58 705 -1v19 -2 car rier level Pages: at t he11CM in put , in clu siv e of 28 abov e signal lev el v ariat ions

17 dBm V

Low est an alog v ideo car rier level 5 dBm V at t he CM inp ut , in clusiv e of abov e signal lev el var iat ion The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Good engin eer in g, d esign , and m aint enance p ract ices for CATV plan t s ensur e t hat t hese t r adit ional video par am et er s can easily be m et an d m aint ain ed f or oper at ional sy st em s. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Par am et er s of pr im ary con cer n, h ow ev er, relat e t o sig nal lev el and noise. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Tab le 2 2 - 2 . Upst r ea m Cab le Specif ica t i ons

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Assum es a l l cond it i ons pr ese nt I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat U pst re am concurr en t ly enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast used edge in t oday ' s net w ork ing Frequ en cy ran ge er t he t er m s, con cep t s, t echn ologies, an d 5devices t o 4 2 MHz, t o edge indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Tr ansit m ostan dist CM nearest CMsecur or CMTS Less t han t og,0.scalabilit 800 m s y, Com plet ed elay w it h, new d uant pdat edt ochapt er s on it y , st or age, opt ical or netequ w oralk in and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Car r ier - t o- n oise r at io Not less t han 2 5 d B net w or kin g p rof essionals, r egar dless of ex pert ise. Car r ier - t o- in gr ess p ower ( t he sum of d iscr et e and Not less t han 2 5 d B Reader w ill ingr obt ain g reat der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e br oadbsand ess asig nals)err un at io har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on r ier -rtang o- inet er hestsu ms of noise, dist ort , ing detNot less t han 5 ds,Brev iew quest ions aCar b r oad off er intence egr al( tsy em and serv ices, inion clud ailed descr ipt2ion d istcomp or t ion, crossm odulat ion) and r at ioad dit ional r esou r ces f or fu rt her st udy . t ocom en mon su re pat con hcept r ehand en sion and r et en t ion, Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Car r ier hum m od ulat ion Not gr eat er t h an 23 dBc ( 7 per cen t ) syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich prBur of essionals emlon per fortm ance st n oise oper at e. Tools and gu id elines f or opt im izing syst Not ger han 10 wmills incr at aease 1 k Hz pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m akeavmor e in t elligent , cost eff icient er age rat e for m ost cases decisions for t h eir net w ork s. Am plit ud e rip ple 0. 5 dB/ MHz ( 5 42 MHz) Gr oup delay r ipple

20 0 n s/ MHz ( 5 42 MHz)

Micr oreflect ions: single echo

10 dBc at less t han or equal t o 0 .5 ms 20 dBc at less t han or equal t o 1 .0 ms

•

Table of Content s

• Season al and I ndex diu rn al signal lev el var iat ion

20 dBc at less t han or equal t o 1 .0 ms Not gr eat er t h an 8 d B m in t o m ax

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

The g r eat er challenge f or t h e oper at or is t o realize suff icient usable u pst ream b andw idt h t o Pub lishter: achieve he Cisco syst Press em s t hr oug hpu t r equir ement s for dat a or ot her ser v ices. The lim it ed upst r eam banPub dw idt ust t en shar ed w it h ot her serv ices, r ang ing fr om im pulse pay - p er - v iew ( I PPV) , Dath e: m Sep temof ber 1 1,b2e 003 t elem etI SBN: r y, and alarm gat her ing infor m at ion fr om t h e act ive element s in t h e cable plant , as w ell 1- 58 705 -1 19 -2 as h aving Pages:t o11com 28 p et e wit h int er fer ing sig nals t hat r adiat e int o t he low er f r eq uency ran ge. Becau se of t he lim it ed and of t en - host ile upst r eam ban dw idt h, t he h ard w are design m ust im plem ent div er se count er m easur es t o m it ig at e t he ef fect s of bot h f ix ed and t r ansient har m fu l noise. I n ad dit ion, t he net w or k designer m ust ch oose f r om t he available r emain in g sp ect r um and oft en m ust im plem en t b andw idt h com pr om ises f or a D OCSI S d ep loy m ent . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial anion d cuoft t up inge tsign ech nologies. A com binat stedg ream al qu alit y m easur ed b y car r ier - t o- noise rat io ( CNR) , ant icipat ed m ar ket penet rat ion , ser v ices of fer ed , and av ailab le upst r eam spect r u m w ill ult im at ely d ict at e t he ph ysical config ur at ion of t he r et ur n- pat h p hy sical lay er . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DOCSIS Standards, Signaling Protocols, and Applications The D OCSI S in t er f ace sp ecificat ions enab led t he developm ent an d deploym ent of dat a- ov er•cable syst emTable s iet ary , m u lt iv endor , in t er oper able basis f or t r anspar ent bidir ect ional s on of a nContent onpr opr •t r ansfer of I nt I ndex er net Prot ocol ( I P) t r aff ic bet w een t he cab le sy st em head en d an d cust om er Ilocat nt e rnions et w orov k ing H a ndbook th Edit er Te anchnologie all- coaxs ial or HFC, Four cable n etion wor k . By Cisco Systems, Inc.

The sy st em con sist s of a CMTS locat ed at t he head end, a coaxial or HFC m edium , and a CM locat ed at t he p rem ises of t h e cust om er , in conju nct ion wit h DOCSI S- defined layer s t hat supp or t Pub lish er: Cisco Press int er operab ilit y and ev olut ion ary f eat ur e capabilit ies t o p er m it f ut u re v alue- add ed serv ices. Pub Dat e: Sep tem ber 1 1, 2 003

DOCSI ISSBN: layer 1- 58d705 ef init -1 19ions -2 ar e as f ollows: Pages: 11 28

I P n et w or k lay er Dat a link lay er com pr ised of : The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of k e Cont rol ( LLC) sub lay er conf orm ing t o Et her net st an dar ds essent ial an-dLogical cu t t ing-Lin edg t ech nologies. - Link secu rit y su blayer f or basic pr iv acy , au t hor izat ion, an d aut hent icat ion Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Access Con t r ol ( MAC) sublay er for op er at ion supp ort in g var iable- len gt h nov ice- tMed o exia pert . pr ot ocol d at a un it s ( PDU) an d feat ur ing: New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP CMTS t rolt echn of con t ent ion atwor ion kt ing r ansmission op por t un it ies Cov erag e of -cut t ing con edge ologies lik eand optreserv ical n et and st or age A st r eam of minislot s in u pst rineam Aut h ored by - Cisco Sy st ems, w or ldw idet he leader net w or king f or t he I n t er n et . - Bandw idt h Hand eff iciency ou gh len h pack et s I n t ern et w or k in g Tech nologies book t, hr Four t h var Ed itiableion , is a gt com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing - er Ex tthe en sion forcon t he f utt s, ur teechn sup por t of Asy nchr onousused Tranin sf er Mode ( ATM) t echnologies. Mast t er ms s, cep ologies, an d devices t oday ' s net w orkoring ot her t y pes of PD U indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, - Suppor t forplet mueltan ip le and w dat aare ratessen es and speed, t h is book is a com d ugrp-ade t o- dofatserv e r efice er ence t oide t her ang t op eicsoft hat t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Phy sical ( PHY) lay er com pr ised of : Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ocols, and ser icesgence inv olvlayer ed . Fu ndam entgalt ot ech nology inf or mat ion0)is pr ov ided on - ot Dow nst r eam convver conf or min MPEG2 ( Rec. H.2 22. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con ceptsical comp r eh en sion and r et en t ion, and er ad for dit :ional r esou r ces f or fu rt her st udy . - Phy Media Dependent ( PMD) sublay Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper- at Dow e. Tools nst r eam and based gu id elines on I TUf orTopt Rec imJ. izing 83 Ann systex em B per w it hforeit mher ance 6 4wor ill incr 256 ease pr odu ct iv it y an d im qupr adr ovat e ur effeiciency, am plit ud help e ming odulat t he ion r eader ( QAM) m ake , con mor cateeninatt elligent ion of Reed, costSolom - eff icient on and decisions for t h eirTrnet ellis w ork f orw s. ar d- er r or corr ect ion ( FEC) , in addit ion t o v ar iable- dept h int er leav ing - Upst r eam , emp loy ing : - Quadr at u re phase shift k ey ing ( QPSK) or 16 QAM

- Suppor t for mu lt ip le sym bol rat es - CM con t rolled and pr ogr am mab le fr om t h e CMTS - Fr equency ag ilit y - Suppor t for fix ed - fr am e and v ariab le- lengt h PDU for m at s • •

Table of Content s e- div ision m ult iple access ( TD MA) , w hich w ork s b y div id ing a r adio - Tim I ndex fr equ en cy in t o t im e slot s and t h en allocat in g slot s t o m ult iple calls. I n

I nt e rn et w or k ing Te chnologie s H awndbook Four th fr Edit ionen cy t his ay , a ,sin gle equ By Cisco Systems, Inc.

can supp ort m ult iple, simu lt aneous d at a

chann els. - Prog ram m able Reed- Solom on FEC and pr eam b les

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2- 003 Capabilit y

t o supp ort fu t ur e ph ysical lay er t echn olog ies

I SBN: 1- 58 705 -1 19 -2

I n addit ion, 11t he Pages: 28 specif icat ion d ef ines m ean s by w hich a CM can self - discov er t he ap pr opr iat e up st r eam an d d ow nst ream f r eq uencies, b it r at es, mod ulat ion for m at , err or cor r ect ion, and pow er levels. To m aint ain equit ab le ser vice levels, indiv idual CMs ar e n ot allow ed t o t r ansm it except und er defined and cont r olled condit ions. The D OCSI S lay ers are r epr esent ed by Figur e 22 - 4 an d are com par ed wit h t h e classic OSI lay er. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r e 2 2 -4 . D OCSI S a nd OSI Pr ot ocol La ye r s

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The D OCSI S p hy sical lay er per mit s con sider able f lex ibilit y t o ensur e q ualit y t r ansm ission can be achieved over cable p lant s of v ar ying q ualit y. Of sig nificance ar e t he opt ional upst r eam ch annel ban dw idt hs and m odulat ion choices av ailable for bot h t he upst r eam and dow nst r eam sig nal flow s.

Based up on band wid t h and mod ulat ion opt ions, in add it ion t o DOCSI S- specified sy m bol r at es, t he t ot al and eff ect iv e dat a r at es of DOCSI S facilit ies ar e sum m ar ized in Tables 22 - 3 t hr ough 22 5. Th e over head generat ed by FEC inef ficiency r epr esent s t he d if fer en ce bet w een t he r espect iv e r at es.

•

Table of Content s

Tab le 2 2 - I3ndex . Nom in al D OCSI S Dow n st r ea m Da t a Rat es i n 6 - M Hz Ch an ne l • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Mod ulat ion t ypInc. e By Cisco Systems, Sy mb ol r at e

64 QAM

25 6 QAM

5. 05 7 MSs

5. 36 0 MSs

30 .3 4 Mbps

42 .9 Mb ps

27 Mb ps

38 Mb ps

Pub lish er: Cisco Press

TotPub al dDat ate:a Sep r attem e ber 1 1, SBN:d at 1- 58 Ef fect Iive a 705 r at -1 e 19 -2

2 003

Pages: 11 28

Tab le 2 2 - 4 . Nom in al D OCSI S Upst r e am Da t a Rat es f or Q PSK The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Band wid t h 20 0 k Hz 40 0 k Hz 80 0 k Hz 16 00 kHz 32 00 kHz Sy mb ol rcise at e ov er v iew s of 0. t16 MSs 32 MSs 64 kMSs 1. 28 MSs 2. 56 MSs Con echn olog ies 0. essen t ial t o n et0.wor ing pr ofession als at all lev els, f rom nov ice t o ex pert . Tot al d at a r at e 0. 32 Mb ps 0. 64 Mb ps 1. 28 Mb ps 2. 56 Mb ps 5. 12 Mb ps Ef fect New ive dchapt at a rer atse include 0. 3cov Mbp erag s e of 0. im6por Mbp t ant s t opics 1. 2like Mbp VoI s P and2.EAP 3 Mbp s

4. 6 Mbp s

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

Tab - 5 .nologies Nom inHand al Dbook OCSI S tUpst e am t aprRat es f or 1ence 6 QAM I n t ern et w orle k in2 g2 Tech , Four h Ed itrion , is aDa com ehensive refer t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Band wid t h 20 0 k Hz 40 0 k Hz 80 0 k Hz 16 00 kHz 32 00 kHz indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet w it ed chapt er secur it y ,0.st or MSs age, opt ical net w or k in g,2.scalabilit Sy mb oler at e h new an d u0.pdat 16 MSs 0.s32onMSs 64 1. 28 MSs 56 MSs y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Totwalordkin at ag rpat e essionals,0.r64 Mbdless ps of1.ex 28pert Mbise. ps 2. 56 Mb ps 5. 12 Mb ps 10 .2 4 Mbps net rof egar Ef fect ive d at a r at e 0. 6 Mbp s 1. 2 Mbp s 2. 3 Mbp s 4. 5 Mbp s 9 Mbp s Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions DOCSI rt her specif iesr eh t hen at sion f or aand sy str em b ecom f unct ional ran d operat ionfual, m andat or. y t o en suSrefucon cept comp et ent toion, andead dit ional esou r ces f or rt her st udy ser ers m int erext face CMTS and s. concep Th ese tserv er salso inclut odeold t her e ,follow ing: Covverag e uisstalso endt he ed n ot only t oCM newdeploym n et wor ent k ing s, but legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease nam Config ur at ion Pr ot ocol ser ver as def y RFC 2, 181 ser ver pr oduDy ct iv it y ic anHost d im pr ov e eff iciency, help ing( Dt HCP) he r eader m,ake morineed in b t elligent cost. - This eff icient pr ov ides need ed I P addr esses for bot h t he CM an d su bseq uent PC d ev ices t hat f ollow . decisions for t h eir net w ork s. Tim e of Day ( TOD ) serv er , as def in ed by RFC 8 68 for t he pu r pose of t ime- st am ping oper at ional sy st em ev ent s. Tr ivial File Tr ansfer Pr ot ocol ( TFTP) ser ver , as def in ed b y RFC 1 350 f or t he pur pose of r eg ist er ing and dow nload in g CM con figu rat ion f iles f or indiv idual cu st omer serv ice. These

conf ig ur at ions could include q ualit y of ser v ice ( QoS) p aram et er s, baseline p riv acy ( BPI ) im plem ent at ion , oper at ing fr equency assignm ent s, t h e num ber of h ost dev ices, and so on . For lar ge- scale deploy m en t s, it is r ecom m ended t hat t hese ser v er s b e supp ort ed by d ed icat ed har dw ar e p lat f or m s t o ensur e r apid syst em r esp onse and scalab ilit y . The D OCSI S specificat ions d ict at e a CM r eg ist r at ion pr ocess as r epr esent ed by Figur e 22 - 5. I n an env iron ment equipp ed w it h a CMTS an d sup por t ed w it h t h e requ ired ser v er s, a CM scans t he • s dow n st r eam Table spectofruContent m w hen it is init ially pow er ed on for a com pat ible RF ch annel car r ying d at a •adh er ing t o DOCSI I ndex S phy sical lay er char act er ist ics. Th e CMTS period ically br oadcast s up st ream Ichann nt e rn et or k ingipt Te or chnologie s Hov a ndbook ion f rom w hich a CM w ill lear n it s assign ed elw descr s ( UCD) er t he, Four DS th ch Edit annel, up Cisco By st r eam Systems, op er atInc. ional fr eq uency . The CM h as now est ablished b ot h a US an d a DS fr eq uency. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Figu r e 2 2 -5 . Cabl e M ode m Re gi st r at ion Se qu en ce

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

[ View full size im age]

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net wCMTS The or kin gp perrof iodically essionals, t r ansmit r egarsdless upst rof eam ex pert band ise. w id t h allocat ion m aps ( hencefor t h r ef er r ed t o as MAP) in shar ed t im e slot s in t he D S dir ect ion . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw The CMTS ar e, assigns pr ot ocols, a t em andpor serary v ices serinv vice olvident ed . Fu if ier ndam ( SI D ent ) (al t y tpically ech nology SI D inf = 0) or mat t o tion he CM, is prwovh ided ich on a b r oadar coar begins ang eseofpow int egr er ran al sy ging st em ( R1 s and using serv 3 ices, dB increm in cludent ings)det anailed d t imdescr e sy nchr ipt ion onizat s, rev ion iewprquest ocessions t o en bet w een su reitcon selfcept an d comp t he CMTS r eh enon sion a cont and ent r et en iont ion, basis and u sing ad dit shar ional ed rtesou im e rslot cess.f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy The CMTS er iodically k eepaliv em o verwify link uit y en bet een ent it self all syst em s, prpovid in g a msend or e rsealist ic pict uressages e of t he trealor ld n etcont w orin k ing virwonm s inanwdhich CM it s in t he sam ain. Whgu enidaelines CM receiv esim it sizing fir st syst k eep alivper em e, itw ill r evincr ert ease s t o a fin e pr ofun essionals oper atee.dom Tools and f or opt em foressag m ance pow erctr iv ang gd ( R2 using dB in crem . r eader m ake mor e in t elligent , cost - eff icient pr odu it yinan im pr ov e 0. eff25 iciency, help en ingt s) t he decisions for t h eir net w ork s. Follow ing t h e R2 pr ocess, a CM is con sider ed t o hav e est ablish ed a link b et ween it self and t he CMTS, but t he lin k w ill be br ok en if 16 consecu t ive keepalive m essag es are lost . On a con t en t ion b asis in shar ed t im e slot s, using a t em por ar y SI D, a CM for w ar ds a band w id t h r eq uest t o t he CMTS, w hich, in t ur n , for w ar ds a gr ant t o t h e CM, perm it t ing it t o f or war d up st r eam inf or mat ion in allocat ed t im e slot s. Th e CM subsequent ly m ak es a DHCP discover y

follow ed by a D HCP r equest . Th e CMTS for w ar ds a DHCP ack now ledgm ent fr om t h e DHCP ser v er cont aining an I P ad dr ess, a default gat ew ay , t he ad dr esses of a TFTP an d TOD ser ver , and a TFTP conf igur at ion file nam e. The CM sub seq uent ly init iat es t he TOD an d TFTP pr ocess. From t he TFTP ser ver , t he CM receiv es a con figur at ion file cont ain in g QoS, secu rit y , ap plicab le fr eq uency assig nm en t s, and any n ew soft w ar e im ages. •

Table of Content s The CM f or w ard s t his conf igur at ion file t o t he CMTS an d in it iat es a r eg ist r at ion r eq uest . I f t he •conf ig ur at ionI ndex file is v alid , t he CMTS assigns t he CM a perm anent SI D an d regist ers t he CM t o Ionline nt e rn etst w at or kuing s. Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Follow ing r egist rat ion , t he CM opt ionally init iat es t he act iv at ion of t he 5 6- bit DES en cr y pt ion algor it hm t o pr ov ide secu rit y b et ween t he CMTS and it self ov er t he cab le plant . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 As CMs r eg ist er , t heir ind ividu al st at us can be m on it ored r em ot ely v ia access comm an ds t o t he I SBN: 1-258 19ines -2 CMTS. Table 2-705 6 d-1ef st at us m essag es fr om a Cisco univ er sal b road band r out er . Pages: 11 28

Tab le 2 2 - 6 . List an d D ef in it ion of Show Cabl e M ode m St at e Com m a nds f r om a one Cisco TS r ef erence p rov ides cover age of The u pdat ed edit ion of t he b est - selling all- innet wCM ork ing essent ial an d cu t t ing- edg e t ech nologies. Me ssa ge

Me ssa ge De fi ni t ion

Con ciseMod ov erem v iew of sider t echned olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Of fline is scon of fline nov ice t o ex pert . init ( r 1) Mod em is sent init ial r ang in g New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP init ( r 2) Mod em is ran ging e ofging cut tis ingcomp edgeletteechn ologies lik e opt ical n et wor k ing and st or age init ( rCov c) eragRan by Cisco Sy st w or ldw ide leader in net w or king f or t he I n t er n et . init ( dAut ) h ored DHCP r eq uest wems, as r eceived ( i)et w or kDHCP r epnologies ly w as rHand eceiv ed; add ress I ninit t ern in g Tech bookI P , Four t h Edwitas ionassig , is aned com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing init ( t ) TOD r eq uest w as r eceived t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu n how t o incor porr at e inteder net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . init (st o)ry . LearTFTP r equest w as eceiv Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, online em isisregist and speed, t hMod is book a comered plet eand an denabled u p- t o- dfor at ed rat efaer ence t o t he t op ics t hat are essen t ial t o all net w or kin rof essionals, r egar dless exwpert online( d) g pMod em is regist ered, butofnet or k ise. access for t he CM is d isabled Reader w )ill Mod obt ain erered, un derBPI st anisding of LAN WAN n et w or k ing, p ar t icu lar ly t h e online(spk em aisg reat regist enabled, anand d KEK w as assigned har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on ) Mod is regist enabled, d ing TEKdet w as assigned aonline( b r oad pt r ang e of em int egr al sy stered, em s BPI and is serv ices, in an clud ailed descr ipt ion s, rev iew quest ions t or ejen su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou ces tfoorbad fu rtMI herC st udy . ect ( m) Mod em d id at t em pt t o regist er ; r egist rat ion w as r efused rdue Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst r ej ect em(s, c) pr ovid Modinem g adm idoratet em r ealist pt tic o regist pict urer e of ; r egist t he realrat ion w orwld asnret efused w or k ing dueent ovirbad onmCOS ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease ectct( pk KEK m odem assignm enting w as rejr ect ed m ake mor e in t elligent , cost - eff icient prr ej odu iv it) y an d im pr ov e key eff iciency, help t he eader decisions t h eirmnet w orkk s. r ej ect ( pt )for TEK odem ey assignm ent w as r ej ect ed

DOCSI S pr escr ibes t hat dat a for w ar ding t hr ou gh t he CMTS m ay be t r anspar en t b ridg ing or , as an alt er n at e, may em ploy n et w or k lay er rou t ing or I P sw it ching. I t also specif ies t hat dat a for w ar ding t h rou gh t he CM is link lay er t r anspar ent br idging w it h m odificat ions allow ing t he

supp ort of m ult iple n et w or k lay er s. I n addit ion, DOCSI S defines gener ic CMTS and CM har dw ar e specif icat ion s t o ensur e m ult iv en dor int er oper abilit y in f ield deploy m en t s. These are su mm ar ized in Table 2 2- 7.

•

Table of Content s

•

I ndex

Tab le 2 2 - 7 . A G en er i c CM TS Ha r dw ar e Specif icat ion

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

P ar am e t er

Cha ra ct e ri st ic

Frequ en cy ran ge

Upst r eam

5 t o 4 2 MHz ( 5 t o 65 MHz of fshor e)

Dow nst r eam

88 t o 860 MHz

Upst r eam

20 0, 4 00, 8 00, 160 0, 3 200 k Hz

Dow nst r eam

6 MHz ( 8 MHz off shor e)

Upst r eam

QPSK or 16 QAM

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Band wid t h

Pages: 11 28

Mod ulat ion m od es

Dow nst r eam 64 or 2 56 QAM The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Sy mbial ol ran at d escu t t ing- edg e t ech Upst r eam 16 0, 3 20, 6 40, 128 0, 2 560 Ksym b ols/ sec essent nologies. Dow nst r eam 5. 05 694 1 or 5. 36 0537 Msy m bols/ sec Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom CMTS pow r ang Dow nst r eam 8 t o 5 8 dBm V ( QPSK) , 8 t o 55 dBm V ( 16 QAM) nov iceert olevel ex pert . e Upst r eam 5 ttoopics + 15 like dBmVoI V P and EAP New chapt er s include cov erag e of im por–1 t ant Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age For t he DOCSI S av ailabilit y crit er ia t o be r ealized or exceeded, t h e har dw ar e m ust sup por t ored bycou Cisco st ems, or pr ldw ide tleader in er net f or t ile he upst I n t err eam n et . . For t he noise-Aut mithig at ing nt erSy measur eswor oper ies t o op at w e or in king t he host up st r eam , t he operat or has a ch oice of eit her QPSK or 1 6 QAM enab lin g op er at ion w it hin a Idegr n t ern et w or k in gbut Tech Hand book t h Ed .it ion , is a com pr ehensive refer ence t hat aded CNR, wnologies it h redu ced spect r al, Four ef ficiency enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast he or t ercor m s, con cep t s, t echn an d devices used in r teduce oday ' st he netamou w ork ing Add it ion ally , f or warerd terr r ect ion ( FEC) can ologies, b e opt ionally conf igur ed t o nt of indua stcorr ry . up Lear t o incor at eorint netopt w or ologBW ies can in t obae LAN/ WAN env ir onm . dat t edn bhow y noise. Fu rtpor herm e,eran imkin al gupt echn st ream select ed by t he operent at or it h new pdateit edher chapt er sspect on secur y , spect st or age, icalned nettw in g,ser scalabilit tCom o fitplet datea w chan nels an betdwueen noisy r u m itor ru m opt assig o or otkher vices. y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net wlast or kin g pntrof r egar ex pert ise. The cou eressionals, measur e av ailabdless le is of a concept of sp ect r um m an agement , in w h ich t he select ed up st r eam f requ en cy , m od ulat ion, an d chan nel ban dw idt h can be alt ered t o ensu re r eliable access Reader w ill obt a gtreat er un der an ding of LAN andsitWAN et w or k ing, t r ansm sission betain w een he CMTS an dst CM in case of t ran or y nnoise p er iods.p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of act int egr alics sy st serv ailed descr ipt s, ing rev iew quest ions The p hy sical char erist ofem t hes and g en er ic Dices, OCSIinSclud 1 .0ing hardet d war e, noisem ition ig at tcount o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . er m easur es, and t he associat ed cable p lan t p aram et ers hav e been d ef ined an d sp ecified in Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Table 2 2- 8. Based on t h is infor m at ion, an d kn owin g t he act ual cab le plant s char act erist ics, t he syst s, can pr ovid in gconsider a m or e deploy r ealist ic urdw e of t he w or lda n et w or k .ing en vir onm ent s in w hich operem at or now ingpict har ar e t o realdevelop pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Tab le 2 2 - 8 . Gen er i c CM H ar d w a r e Sp eci f ica t i on

P ar am e t er

Cha ra ct e ri st ic

CM pow er level r ang e: Ou t put

QPSK: 8 t o 58 d BmV 16 QAM: 8 t o 5 5 dBm V

• I npu t

Table of Content s

•

I ndex

Tr ansm ission lev el

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

15 t o 15 dBm V 6 t o 1 0 dBc

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DOCSIS Hardware Deployment and Resulting Service Capabilities Assu m in g HFC CATV t opogr aph y as show n in Figur e 22 - 6, CMTS equ ip ment could be d ep loy ed at •bot h t h e hub Table Content an d of t he heads en d locat ions. For t h e pu rp ose of t his app licat ion, t he Cisco u niver sal •br oadb and r out I ndex er is considered. The uBR724 6 is an int eg rat ed r out er w it h a capacit y of up t o Ifou nt errncable et w or km ing Te chnologie a ndbook Fourcar th Edit ion odem car ds,s wH it h mod,em ds available w it h one or t w o d own st ream p ort s and fr om one t o six u pst r eam por t s. I n ad dit ion, t h e un iv er sal br oadban d r out er can be eq uipped for By Cisco Systems, Inc. back bone con nect iv it y f rom a lar ge select ion of p or t adap t ers, r ang ing fr om T1 / E1 ser ial t o Packet Ov er SONET ( POS) , t o Dy nam ic Pack et Tr an sp ort ( DPT) and fr om 1 0BaseT Et h er net , Pub lish er: Cisco Press Gigab it Et hern et t o Hig h- Speed Ser ial I nt er face ( HSSI ) . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 2 2 -6 . CM TS De ploy m en t Possi bil it ie s in a Ty pical HFC CATV Pl an t [ View full size im age]

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv ituBR10 y an d 012 im pris ovCisco's e eff iciency, t he r eader ake e inert elligent The Cisco m ost help recening t CMTS. I t h asmm uchmor gr eat capacit, ycost an d- eff in ticient eg rat es decisions for t h eir net w ork s. m or e redu ndan cy , g iving MSO's an opp or t unit y t o ser v ice mor e cust om ers w it h a sm aller foot pr int . Also av ailable is a n ew m odem card , t he MC52 0, w hich supp ort s fiv e dow nst r eam and t w ent y u pst r eam RF dom ains. When select ing t he b ack bon e con nect ion op t ion, an assessment of t he t ot al back bone t raf fic an d t he available m edium mu st be consider ed . I n all lik elihood, f or our ex am ple, t he backb one f rom

t he hub locat ion w ou ld b e t r anspor t ed op t ically t o t he h ead end, w here all t r aff ic wou ld b e agg regat ed by eit her a r out er or an I P sw it ch b ef or e being for w ar ded t o t he I n t er n et or t o t he pu blic swit ched t elep hone n et w or k ( PSTN) . Oft en, t he MSO w ill pr ov ision a cache eng ine at t he head en d t o r educe t h e band w id t h t o t h e I nt er net and , conseq uent ly , r ed uce t he facilit y lease cost . Con nect iv it y t o t he PSTN is oft en r eq uired t o su ppor t eit h er d ialu p I n t er n et ser v ice, v oice, or Telco ret u rn dat a ser v ice. •

Table of Content s

•Telco ret u rn , I ndex if available f r om t he MSO, is as an int er im serv ice off er ing because it s plan t It opog nt e rn et w or k ing Te not chnologie a ndbook Four tht o Edit r aphy h as beens fHully up gr, aded t wion o- w ay

oper at ion. I n such applicat ions, a h ighspeed By CiscodSystems, own st ream Inc. conn ect ion is est ab lished ov er t he HFC p lant , w h er eas t he u pst r eam connect ion is est ablished via a Point - t o- Poin t Pr ot ocol ( PPP) connect ion ov er t h e t eleph one net w orlish k, er: w itCisco h a Press dialup m odem at t he cust om er pr emise and an access ser v er collocat ed at t h e Pub ServPub iceDat Pre:ovider s Facilit y . Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 To em ph asize t h e engineer in g con sider at ions n ecessar y f or est ab lishin g a DOCSI S net w or k, a 11 28 case m od el will b e evaluat ed . The r elev ant business par am et er s ar e sum m ar ized simp lePages: business in Table 2 2- 9. Th e analy sis consider s only r esid en t ial and limit ed bu siness cust om er s sup por t ed by t he head end locat ion .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Tab le 2 2 - 9 . Fi ve -Ye ar Busin e ss Pla n Su m m ar y

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Pla nt Grice owt ot hex pert . 0 . 7 5 P er ce nt pe r Ann um nov High- sp eed dat a ser vice of fer ed : New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Resident ial 25 6 Kb ps DS 12 8 Kb ps US Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Business 1. 5 Mbp s DS 51 2 Kb ps US Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Penet r at ion r at es: I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net and an dinim en t wit cont y tint er net w ork ing Resident ialw or kin g p r ofessionals t o un derst 3 per cent firplem st y ear h em 30 por p er ar cen CAGR t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Business Twwoorinkin y ear t w o;olog addies onine t per y ear WAN t hereaf t erir onm ent . indu st ry . Lear n how t o incor por at e int er net g t echn o a LAN/ env Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Analy sis assum pt ion is s: a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all and speed, t h is book net w or kin g p rof essionals, r egar dless of ex pert ise. Resident ial act ivit y fact or 25 per cen t Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Business act iv it y f act or 25 per cen t har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on aDat b r oad r angfact e of in clud ing det ailed descr ipt ion s, rev iew quest ions a peak orint egr al sy st em s and serv 8 ices, per cent t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich The b usiness plan in e. dicat es t and hat tgu heidDOCSI serv is for syst an ex istper ing for serv ing arwea hat ease w ill pr of essionals oper at Tools elines Sf or optice im izing em m ance ill tincr exp er ience m oderat e gr ow t h, p rob ably lim it ed t o new hom e const r uct ion, ov er t h e plan period . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient The op er at or in t ends t o off er a sing le dat a p r oduct t o each of t h e r esident ial an d business user s decisions for t h eir net w ork s. w it hin t he ser ving ar ea. Penet r at ion r at e is t he per cen t age of t ot al hom es passed in t he serv ing ar ea and r ep r esent s t h e nu mb er of cu st omer s w ho buy t he ser v ice. The act iv it y fact or r epr esent s t he p er cen t age of sub scr iber s w ho ar e act iv ely on lin e eit h er

up load ing or dow n load ing in for m at ion. The peak f act or r epr esent s t he r elat ionship bet w een t he p er ceiv ed or appar ent band w id t h load of a sy st em com p ared t o t h e act ual f init e b andw idt h av ailab le fr om t h e ph ysical CMTS deploy ment . Peakin g r eflect s t he f act t h at d at a t r ansf er t o an indiv idual user is t yp ically d ur in g in t erv als of inst ant an eou s du rat ion . The cab le plant in fr ast r uct ur e ( head end ser v in g ar ea) t hat is con sider ed f or t h is deploym ent has • Table of Content s char act er ist ics, assigned sp ect r um , an d select ed m odulat ion as sum m arized in Table 2 2- 10 . •

I ndex

IThe nt e rn w orend k ing supp Te chnologie H a ndbook Fourar thea Edit h et ead or t s aslocal serv,ing ofion 25 ,0 00

hom es passed , dist r ib ut ed amon g 25 optCisco ical n odes w it h u pst r eam CNR ran ging fr om 30 t o 3 6 d B. The CNR is a sig nificant par am et er By Systems, Inc. because it d ict at es t h e nu mb er of nodes t h at can be com bined in t o a sin gle r eceive por t . DOCSI S r eq uir es a CNR of 25 dB, ir r esp ect iv e of t he u pst r eam mod ulat ion ch osen for cer t ified operat ion . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Tab le 2 2 - 1 0 . He a d En d Ser v in g Ar e a Ch ar a ct e r ist i cs a nd Av ai la ble Spect r um HFC char act erist ics Dow nst r eam : 88 t o 750 MHz The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t Upst ech nologies. r eam : 5 t o 42 MHz Head end serv ing ar ea 25 ,0 00 hom es passed Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . 25 nod es ( aver age of 1 ,0 00 hom es each ) New chapt er s include cov erag e of por ant 3t opics and EAPof 32 dB CNR v ary ingimbet wteen 0 an dlike 3 6 VoI dB; Pav er age Av ailab sp ect r um Dowt echn nst r eam : EI A annel 43k9. 25 and MHzst or age Covleerag e of cut t ing edge ologies likch e opt ical6n0etatwor ing 32ide MHz, 80 0 inkHz w id t fhor t he I n t er n et . Aut h ored by Cisco Sy stUpst ems,r eam w or :ldw leader netband w or king Dow nst rbook eam,: Four 64 QAM I nMod t ernulat et wion or k in g Tech nologies Hand t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Upst r eam : QPSK t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, The QPSKisana dcom band wid h dofu8p00t o-k dHz w ill pact tthoet he r et ut op rn ics p atthhat d atare a t hr ough putt o all and select speed,ion t h of is book plet e tan at e r efim er ence essen t ial rnet at e. w or kin g p rof essionals, r egar dless of ex pert ise. From v ariab les, y earofcust omand er and pr kofile ary Readert he s wbillusiness obt aincase a g reat er un derastfiv ane-ding LAN WANt r naff etic w or ing, sum p ar tm icu lar is ly pr t hep e ared and sum m ar as inand Table 2- 11inv . olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on har dw ar e, prized ot ocols, ser v2 ices a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions The able t hat rt eh heen num of rhetomes p assed andit d tional he p en et r atr ces ion fr or at es hav increased t o ent su re indicat con ceptescomp sionber and en t ion, and ad r esou fu rt here st udy . considerab overext t hend e evaluat , w it t he rnesu lt ant perceived id t h tt oo b e er pr,ocessed Cov erag e islyalso ed n otion only t oh new et wor k ing concep t band s, butwalso old legacy by t he CMTS entin g at at he head en d.ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich syst emequipm s, pr ovid m or e r ealist pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease The n um of dCMTS un eit seff t oiciency, sup por help t t heing pert he ceivr eader ed loadmm ustmor b e edet ined , consid er icient ing t h e use pr odu ct ivber it y an im pr ov ake inerm t elligent cost - eff of t he Cisco uBRMC16C consist in g of on e dow nst r eam and six up st r eam por t s. Fir st , how ever , a decisions for t h eir net w ork s. v alid up st ream ag gr eg at ion scenar io m ust b e est ab lish ed . Con sider com binin g t h r ee n odes, each hav ing a CNR of 3 6 d B, r esult in g in an aggr egat ed CNR of app rox im at ely 27 dB t hat com for t ab ly ex ceeds t he DOCSI S cr it er ia. We m ust now d et er m ine t h e quan t it y of CMTS unit s t o sat isfy t h is applicat ion:

25 nod es/ 3 nod es per r eceiv er = 9 r eceiv er s, ind icat ing a need f or t w o u BR- MC1 6C unit s Con sider ing t he 8 00 k Hz QPSK upst r eam limit at ion s, t he h ard war e select ion m ust b e validat ed against t he t raf fic an aly sis for t he b usin ess p lan , as sum m ar ized in Table 2 2- 11 .

•

Table of Content s

•

Tab le I ndex

2 2 - 1 1 . He a d En d Cust om e r a nd Tr af f ic Pr ofi le

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Y ea r 1

Y ea r 2

Y ea r 3

Y ea r 4

Y ea r 5

H om p assed Pub es lish er: Cisco Press

25 ,0 00

25 ,1 88

25 ,3 76

25 ,6 66

25 ,7 58

Dat Sepcust tem ber 1 1,er 2 003 RePub side nte:i al om

75 0

98 2

12 86

16 85

22 07

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2

3

4

5

DS 48M

DS 64M

DS 84M

DS 100 M

DS 144 M

US 24 M

US 32 M

US 42 M

US 55 M

US 72 M

I SBN: 1- 58 705 -1 19 -2

Busin ess cust om er Pages: 11 28

Tot a l t ra ff ic

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. D ow nst re am V al ida t i on Conocise ovMC1 er v iew of t echn olog t o n et worpar k ing als atirem all ent lev els, rom8 Tw u BR6C sr esult ing in 2 xies27essen = 5 4t ial Mbps, com ed pr t oofession Year 5 requ of 1f44/ nov o ex pert . = 1 ice 8. 1 tMbps ( w here 144 Mbp s is t he Year 5 ap par en t BW and 8 is t he d at a p eak ing f act or ) New s include U pst chapt re am erVa l ida t i oncov erag e of im por t ant t opics like VoI P and EAP Cov e MC1 of cut t echn e opt ical k ingan and st orkage Tw oerag u BR6Ct ing w it edge h 9 act iv e rologies eceiver slikconfig ur edn et f orwor QPSK d 800 Hz BW, r esult ing in 9 x 1. 2 = 1 0. 8 Mbps, com par ed t o Year 5 requ irem ent of 7 2/ 8 = 9 Mb ps ( w her e 72 Mb ps is Aut ored 5by st ems, w or f or t he I n t er n et . t he hYear apCisco par enSy t BW and w8 or isldw t heide d atleader a p eakin ingnet fact orking ) I n t ernSu et w or k ibe in g rTech bscr Li mnologies i t V a l idaHand t ion book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. er ert he er m s,5 con s, t sechn ologies, usedis in t oday ' s net w ork ing The t ot alMast nu mb of t Year subcep scr tiber is 220 7 + 5an = d22devices 12, w hich w ell w it hin t he indu stsugg ry . Lear n how o incor atscr e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . est ed lim it tof 120 0por sub ibers per CMTS. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Based on t he analysis h is sim b usin ess heerin it ial tdeploy CMTS har dwtar and speed, t h is book isofa t com pletple e an d u pt o-case, d at e rtef ence o t he tment op ics of t hat are essen ialet w o ill all m eet of t he ent irr egar e fiv eyearofp ex lanpert an dise. b ey ond , w it hou t com pelling t h e oper at or t o net w ort he kinngeeds p rof essionals, dless up gr ade t h e configu r at ion. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Future DOCSIS Applications This chap t er descr ibes t he DOCSI S 1. 0 p r oduct d ef init ion int ended t o sup por t h igh- speed dat a ov er a cable net w or k . The m ost r ecen t ev olu t ion of t he DOCSI S st andar d is DOCSI S 1. 1. I t supp ort s addit ion al ser v ices t od ay and w ill ease t h e deploy m en t of f ut ur e ap plicat ion s, wh ich •coincid e w it hTable of Content s pr oduct en hancement s t o sup por t t he needs of t h e m ark et t o ensur e net w or k •r eliabilit y , and I ndex hig h sy st em availabilit y . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Planned fu t ur e serv By Cisco Systems, Inc. ices an d applicat ions include t eleph ony based upon Voice over I nt er net Pr ot ocol ( VoI P) , v ideo ov er I P using Mot ion Pict ur e Ex per t Gr oup ( MPEG) f r am e for m at , QoS, and enhan ced secur it y def in it ions. At t he sam e t im e, CM an d set - t op box ( STB) dev ices capab le of Pub lish er: Cisco Press supp ort in g t hese and ot her ser v ices ar e b eing int r od uced . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 When considering t h19e-2sim u lt an eou s supp ort of t hese new ser vices and applicat ions, a mor e ext ensiv Pages: e plann 11 28 ing con cept m ust b e considered.

The D OCSI S 1 . 1 specificat ion p rov ides t h e follow ing fu nct ional enh ancem ent s ov er DOCSI S 1. 0 coaxial cab le net w ork s: The uEn pdat ed edit ion tof t heebpr est - selling in-t ime one tnet w ork ing ras ef erence p rov ides cover age of hanced QoS o giv iorit y for allr ealraf fic, such v oice an d video: essent ial an d cu t t ing- edg e t ech nologies. - The DOCSI S 1. 0 QoS mod el ( a serv ice I D ( SI D) associat ed w it h a QoS p rof ile) has Con cise ov err eplaced v iew s ofwt echn ies essen t ial t o nt hetatwor k ings pr ofession als at yallinlev els, f rom been it h a olog ser viceflow m odel allow gr eat er flex ib ilit assigning nov iceQoS t o ex pert . par am et er s t o diff er ent t y pes of t r aff ic and in r espondin g t o chang ing band w id t h condit ions. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP - Suppor t for mu lt ip le ser v ice f low s per cable m odem allow s a sing le cab le mod em t o Cov erag e of ing edge t echn lik e opt ical n et wor ing and st or age supp ortcut a tcom bin at ion of ologies d at a, v oice, and v ideo t r afkfic. Aut h ored Syular st ems, or ldwper ide cable leadermin net winoreit king he ion I n t,erusing n et . unid ir ect ional - Grby eatCisco er g ran it y inw QoS odem herf or dirtect ser v ice flow s. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net-w Dyn or kin gp an d ,im en te cont por ar y int ersnet ork ingt am icr ofessionals MAC messagt oesuncrderst eat e,and m odify anplem d d elet t r af em fic serv ice flow t o wsu ppor t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing on- d em an d t r af fic r equest s. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet w itthednew u pdatfor ed tchapt on secur Supepor QoSanmdodels he uper st sream ar e: it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g -pBest rof essionals, r egar ex pert - ef for t — Dat a t dless raf fic of sent on aise. non - guar ant eed best - ef for t basis. Reader s w ill- Com obt ain g reat ermun aneding of— LAN and n et w orum k ing, p arwtid icu ly dt hatea m itat ed in for atder ion str at ( CI R) Guar antWAN eed minim band t hlarfor har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on t r aff ic. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp enssion and—r et en t ion, adedit ional trresou f orasfuvrtoice, her st udyis . - Unsolicit ed gr eh r ant ( UGS) Const ant and bit rat ( CBR) aff ic,r ces su ch t hat Cov erag e ischar alsoact ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy er ized b y fix ed- size packet s at f ix ed in t erv als. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals opert at Tools and gu id— elines im izing systs, em per for ill incr ease - Realime. e polling ( RTPS) Real-f or t imopt e ser vice flow such as m v idance eo, twhat pr oduce pr odu ct iv it yun anicast d im, pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient v ar iable siz e packet s at fix ed in t er v als. decisions for t h eir net w ork s. - Unsolicit ed g r ant s w it h act ivit y d et ect ion ( USG- AD) — Com binat ion of UGS and RTPS t o accom mod at e r eal- t im e t r af fic t h at m ight hav e p er iods of inact iv it y ( such as v oice u sin g silen ce su ppr ession) . The serv ice flow u ses UGS fix ed gr an t s w hile act ive, bu t sw it ches t o RTPS polling du rin g p er iods of in act iv it y t o avoid w ast ing band w id t h.

En hanced t im e- slot scheduling m ech anism s t o supp ort gu aran t eed delay and j it t er sen sit iv e t r aff ic on t he shar ed mu lt iple- access upst r eam lin k. Pay load Header Sup pr ession ( PHS) conserv es link - lay er ban dw idt h by su ppr essing un necessar y p ack et h ead er s on bot h u pst r eam and dow nst r eam t r aff ic flow s. Lay er 2 fr agm ent at ion on t he u pst r eam pr ev ent s lar ge d at a p ack et s f rom aff ect ing r ealt im e t r aff ic, su ch as vsoice and v id eo. Lar ge d at a p ack et s ar e fr agm ent ed and t hen • Table of Content t r ansm it t ed in t he t im e slot s t h at ar e av ailable bet w een t h e t ime slot s used f or t he r eal• I ndex t im e t r aff ic. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Con cat enatInc. ion

allow s a cable m od em t o send mu lt iple MAC fr am es in t he sam e t ime slot , as opp osed t o m ak ing an indiv idual g r ant a r eq uest f or each fr am e. This av oids w ast ing Pubup lishster: Cisco bPress r eam andw idt h w hen sen ding a n um ber of v er y sm all pack et s, such as TCP ackn ledg t pack Pub Dat e:ow Sep tem m beren 1 1, 2 003 et s. I SBN: 1- 58 705 -1 19 -2

Adv anced au t hent icat ion and secur it y t h rou gh X. 509 digit al cer t ificat es and Tr iple Dat a Pages: 11 28 En cr y pt ion St and ard ( 3 DES) key encr yp t ion. Secu re sof t w ar e dow nload allows a serv ice pr ovid er t o r emot ely up gr ade a cable m odem' s soft w ar e, w it hout r isk of in t er cept ion or alt erat ion . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary Hist orical coax ial br oadcast n et w or k ing w as descr ibed in t h is ch apt er , and it s inh er ent lim it at ions t o value- ad ded serv ices wer e ident if ied . HFC net w or k in g was in clu ded, w it h a b rief descr ipt ion of it s adv ant ages and benefit s cap able of supp ort in g h igh- speed d at a conn ect iv it y. •

Table of Content s

•The lim it at ions I ndex of p rev ailin g HFC desig ns, DOCSI S av ailab ilit y cr it eria, an d requ isit e cable p lan t Ispecif nt e rn et w or k ing Te chnologie s H a ndbook th essed Edit ionas w ell. icat ion s and t erm inolog y w er ,eFour ad dr By Cisco Systems, Inc.

I n addit ion, t his chapt er su mm ar ized t h e DOCSI S st andar d, sign alin g pr ot ocol, requ isit e supp ort in g ser ver s, gener ic pr oduct sp ecificat ions, an d ap plicat ion s. Repr esent at iv e CM st at us Pub lish er: Cisco Press m essages as v iewed at t he CMTS w ere p r ovided t o r eflect p aram et ers and t ools crit ical f or t he Dat e: Sep tem ber 1 1, a2 003 operPub at ional aspect s of DOCSI S sy st em . I SBN: 1- 58 705 -1 19 -2

Finally, f ut u11 re28ser vices and app licat ions wer e ident if ied t o coincide w it h t h e ev olut ion t o DOCSI S Pages: 1. 1.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

Descr ibe t he adv ant ag es or benefit s off er ed b y an HFC net w or k .

2:

I ndexif y t he p rocess of pr ovid in g t w o- way operat ion of an HFC cable p lan t . I dent

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

: Descr ibe By Cisco 3 Systems, Inc.

t he up st ream an d d ow nst ream b andw idt hs associat ed w it h t h e DOCSI S st andar d .

Pub lish er: Cisco Press

4:

Sum m ar iz e t he D OCSI S av ailabilit y cr it er ia.

Pub Dat e: Sep tem ber 1 1, 2 003 I5 SBN: 58 705if-1 -2 : 1I dent y 19 t he

D OCSI S- defined net w or kin g lay ers.

Pages: 11 28

6:

I dent if y t he D OCSI S 1 .0 serv ers, an d descr ibe t heir r esp ect iv e pu rp oses in t he net w or k.

7:

What ar e t he facilit ies in w hich an MSO m ight deploy t h e univ ersal b r oadband ? of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of The u pdat edr out editerion essent ial an d cu t t ing- edg e t ech nologies. 8 : Defin e Telco r et ur n and t ell w hen t his app licat ion m ight be consider ed . Con 9 : cise List ov er a few v iewof s of t het echn pr oper olog t ies ies and essen fu t ial ur et oapp n etlicat worions k ingassociat pr ofession ed w als it hatDOCSI all levSels, 1. 1. f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information Books •

Table of Content s

•

I ndex

•I nt Az and Niel oadban d Access Techn ology . New Yor k : McGr aw - Hill, 199 9. e rnzam, et w or kAlb inger Tet ,chnologie s HRansom a ndbook ,. Br Four th Edit ion By Cisco Systems, Inc.

• Cicior a, Walt er , Jam es Far m er, and Dav id Lar ge. Mod er n Cable Telev ision Technology . Bost on: lishKauf er: Cisco Press MorPub gan m ann Publisher s, I n c. , 1 998 . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

• Gr ant , William . Cab le Telev ision , Th ir d Ed it ion . New Yor k: GWG Associat es, 199 7. Pages: 11 28

• Raskin, Donald, and Dean St oneback. Br oadban d Ret ur n Sy st em s for Hy br id Fiber/ Coax Cable TV Net w or ks. New Yor k : Pr ent ice Hall PTR, 1 997 . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of • Thom as, Jef f. Cab le Telev ision: Pr oof of Per for m ance. New Yor k : Pr ent ice Hall PTR, 1 995 . essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing URLs

pr ofession als at all lev els, f rom

nov ice t o ex pert .

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP • w w w .cablelabs. com Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age • w w w .cablem odem .com Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I• nwt w ern et w or kelep in g Tech Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat w .cablet honynologies . com enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing ry . Lear •indu w w st w .cat v . or gn how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

Magazines

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on •aCab levision 773 Rid Blvd ., Hig hland Ran ch det , Coailed 801 26. b r oad r ang.e8of intSout egr alh sy stgelin em s eand serv ices, in clud ing descr ipt ion s, rev iew quest ions w w .cablev isionm ag .com t owen su re con cept comp r eh. en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich • Cab lew orld. I nt er t ec Pub lishing , a Prim edia Comp any , 98 00 Met calf Av e., Ov er land Par k, KS pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease 66 212 - 221 5. w w w .cablew or ld . com . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. • CED ( Com m un icat ion s En gineer ing & Design) . P. O. Box 266 007 , Highland Ranch, CO 8 0163 60 07. w w w .cedm agazine. com.

Chapter 23. Introduction to Optical Technologies • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Lear n about diff erent app roaches t o opt ical n et w or k ing.

By Cisco Systems, Inc.

Under st and t he d if fer en t m et hod s of buildin g op t ical net w ork s. Pub lish er: Cisco Press

Lear n Sep about diff1 erent Pub Dat e: tem ber 1, 2 003 opt ical

n et w or k t op ologies.

I SBN: 1- 58 705 -1 19 -2

Op t ical net w ork s p rov ide t h e m ean s t o t ran sp ort aud io, v id eo, and dat a acr oss opt ical Pages: 11 28 t r ansm ission and sw it chin g sy st em s. This chap t er inv est igat es t r ad it ion al ar ch it ect u res, such as SONET/ SD H, and em er ging p arad ig m s, su ch as I P over DW DM, Gig abit Et her net , and ATM. Recen t ly, eq uipm ent an d st an dar ds b odies hav e st art ed dev elop in g t he m eans t o sig nal an d sw it ch opt ical n et wor k s. This chap t er discu sses r ecent developm ent s in m anaging an d cont rolling opt ical n et w or k s fr om t he I ETF, OI F, and I TU. Addit ion ally , t h ese or gan izat ion s m ust d ecide h ow ed edit ofh tthe est - selling all- in- one net w ork ing r ef erence p rov ides cover age of tThe hey uwpdat ill conv erg ion e w it he bot her s' pr oposals. essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

What Is Optical Networking? Op t ical net w ork s ar e net w or k s pr ov id ing opt ical pat h s bet w een ser v ice pr ovid er s an d cust om ers. Op t ical net w ork s ar e pr ov ided bet w een cor por at ion s and hom es t hr oug h Fiber To The Hom e ( FTTH) . Op t ical net w ork s p rov ide t h e necessar y infr ast r uct ur e t o meet b andw idt h n eeds t oday •and in t he f utTable Content s ed ia allow s nar r owb and, w id eb and, and br oadb and applicat ions t o u re. of Opt ical m •be n et wor k ed. I ndex As t h e desire f or ban dw idt h incr eases, opt ical net w or k s ar e t r uly t he on ly m ed iu m It o nt emeet rn et w tor Te chnologie s H a ndbook , Four th Edit h keing ever - exp anding dem and s for d at ion a capacit y incr eases. By Cisco Systems, Inc.

Fur t her in g t he d iscussion of opt ical n et wor k ing is w hat com p rises t he op t ical net w ork . Th er e ar e m any op in ions on w hat arch it ect ur e is b est for t h e dev ices, cross- connect s, and swit ches u sed. Pub lish er: Cisco Press This sect ion f ocu ses on r eal deploy m en t only , em phasizing lar ger deploy ment s. Opt ical net w or k s Dat e: Sep tem ber 1 1, 2 003 alsoPub m ak e use of elect r ical ch aract er ist ics; t h er efor e, t his chap t er cov er s leg acy eq uipm en t in I 19 -2 exist ingSBN: ent 1er58 pr705 ise-1an d ser vice pr ov ider net w or ks as w ell. Pages: 11 28

The f ollow in g sect ions br iefly describ e t he v ar ious t y pes of opt ical n et w or k s.

Wave Division Multiplexing and Dense Wave Division Multiplexing The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ingedg e t(ech nologies. Wav e Div ision Mult ip lex ing WDM) and Dense Wav e Div ision Mu lt ip lex ing ( DWD M) p rov ide opt ical p at hs t o and fr om ser vice pr ov iders w hile using t ight ly spaced opt ics. I TU sp aced opt ical t r ansm it t er s, w hich ar e filt ered using a v ar iet y of filt ering t echniq ues ( such as arr ay w av e Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom gu id es) , and opt ical am plifier s ( such as EDFA) allow b ot h cir cuit - sw it ch ed and d at a circu it s t o b e nov ice t o ex pert . deliver ed . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e ofHome cut t ing Fiber to the

edge t echn ologies lik e opt ical n et wor k ing and st or age

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Op t ical net w ork s ar e net w or k s pr ov id ing opt ical pat h s dir ect ly b et w een ser vice pr ov iders and cust ometerws' Using lead ingedg e opt ical tinf r ast r uct allow ser v ice pr ovider s ttohat cost I n t ern orhom k in ges. Tech nologies Hand book , Four h Ed it ion , uisres a com prsehensive refer ence eff ect iv ely p rov ide b andw idt h d irect ly t o cust om er s. FTTH is t r uly br oadb and con nect iv it y f oring enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork tt elecom m ut er s. FTTH allow s f or conv er g ed m ult im ed ia and it s g row t h as t he need for b andw idt h echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing gr ow s. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rofNetworks essionals, r egar dless of ex pert ise. All-Optical Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e All- Op t ical Net w ork s ( AONs) ar e n et wor k s pr ov iding opt ical p at hs b et w een ser vice pr ov iders an d har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on cust om er s. All op t ical net w ork s ar e t h e m ean s t o t r an sp ort and sw it ch circuit s and packet s a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions ph ot onically . By t ran sp ort in g an d sw it ching ph ot onically , ent er pr ise and ser v ice p r ovider s can t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . r ed uce t he amou nt of eq uipm ent r equ ir ed t o r egenerat e elect rical sign als. Th e adv ant ag e of Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy using AONs is in r ed ucing t he cost of b uilding and m anag in g t he opt ical n et wor k . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease AONs ar e n et w or k s t hat allow ser v ices t o r un dir ect ly ov er fiber w it hou t in t er v en ing layer s—in pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient ot her w or ds, st ay ing in t he ph ysical or p hot onic lay er. Because of v ar iou s issues w it h decisions for t h eir net w ork s. t r anspor t ing ph ot ons in opt ical f iber, net w ork pr ovid er s use elect r ical am plifier s and r eg en er at or s. AON uses t echn iques in t he t r an sp ort at ion of solit ons w it h opt ical am plifier s ( Ram an) in opt ical fib er t o allow signals t o not r eq uir e elect r ical r egener at ion, r et imin g, an d r eshap ing. Much lik e ph ot ons, solit ons h ave d ist an ce lim it at ions; how ev er , solit on s can b e t un ed and r esh aped in t he phy sical lay er . Sw it ch in g AONs can also b e accom p lished phot on ically . Sever al opt ical t echn iq ues ( such as MEMS) allow ph ot onic signals t o be sw it ched.

All opt ical n et wor k s ar e br ok en int o m et ro opt ical net w or k s and core opt ical net w or ks.

Metro Optical Networks Ex plosive gr ow t h in I nt er net an d ent er pr ise applicat ions is p ushing global en t erp rise and serv ice pr or ks. ex amp le, ap plicat ion s such as e- business, st or age con solidat ion , and • ov ider net w Table of For Content s m ult iser v ice in t eg r at ion ar e chan ging t he lan dscap e for en t er pr ise and ser v ice pr ovid er s. Met r o • I ndex opt ical n et w or k s encomp ass m et r o, access and I nt e rn et w or k ing Te chnologie s H a ndbook Four th Edit ionm et r o cor e. Met r o op t ical net w ork s ar e bet w een t he cent r al office an d/ or serv ice point s of p r esence ( POPs) t o m ajor su bscr iber p oin t s ( access By Cisco Systems, Inc. net w or k) . Ser v ices ar e t y pically gr oom ed int o larg er dat a/ cir cu it pip es f or t r anspor t at ion . Pub lish er: Cisco Press Pub Optical Dat e: Sep tem ber 1 1, 2 003 Core Networks I SBN: 1- 58 705 -1 19 -2 Pages: 28 w ork s lie bet w een cent r al of fices an d/ or ser vice POPs an d con nect each ot h er Cor e op t ical11net w it h fiber suit ed for lon g- hau l, ex t end ed long- haul, an d u lt ra- lon g- hau l t r ansm ission. Bu lk ser v ices, w hich are gr oomed fr om m et r o op t ical net w ork s, ar e t r anspor t ed over long dist ances t o ot her cent r al of fices and/ or ser vice POPs. See t h e sect ions " Lon g- Haul Net w or k s, " " Ex t ended Lon g- Haul Net w or k s, " an d " Ult ra- Long- Hau l Net w ork s" for m or e det ails. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Passive Optical Networks Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Passivnov e Op Net w or icet ical t o ex pert . k s ( PONs) can be b r oken int o t wo m ark et s—r esident ial an d business. Alt hou gh PONs can be considered a m at u re and deployed t ech nology , t h ey fall v ery shor t of lar ge-New scalechapt deploy en t . PONs con sist Opt w ork like UnitVoI s ( ONUs) and Opt ical Net w or k er sminclude cov erag e ofofim porical t antNet t opics P and EAP Term inals ( ONTs) . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Ty pically , PONs are b uilt f or net w or k s looking f or cost adv ant ag es w it h asy mm et r ical band w id t h ored by uCisco Sy st ems, w or ldw idesplit leader net w or king t he I n tcan er n et . t r an sp ort ed r eq uirAut emhent s. By sin g econom ical opt ical t er s, inopt ical pow er f(or signals) be t o mu lt iple locat ion s. Generally d own st ream t r af fic ( t r af fic f rom t he serv ice pr ov id er ) t o t h e I n t ern in g Tech nologies Fourttrhaff Ed , ist ha ecom ehensive t hat cust ometerw or is khigher b andw idt h Hand t h an book upst r,eam icit(ion fr om custpromer ) . Alsorefer em ence ploy ed ar e enables netdwist orrkin p r ofessionals t o unopt derst and ansceiv d imer plem t ost contcases, em porPONs ar y intar erenet w ork low er - cost ibugt ed f eedb ack ( DFB) ical t r an s. I nenm used b ying t echnologies. t he t er m s, con ologies, devices ' s net com panies, suMast ch asercable com pan iescep antds, uttechn ilit ies. PONs an cand also be pused ar t ofinat oday hy br id n et w w ork or king . indu t o use incorofpor at e int er net w or t echn olog in tmu o alt LAN/ WAN env ir onm Hy brst idryn.etLear w ornk show m ake PONs' low cost t okin prg ovide con veries ged im edia br oadban d ent . Com plet easww it h anist d in u pdat ed chapt on secur y , st or age, opt ical net w or k in g, scalabilit y, ser v ices ellnew as ex g legacy nar rer ows band servitices. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

Residential anda gBusiness Reader s w ill obt ain reat er un der PONs st an ding

of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad Ther e ar reang t w oe kofinds int egr of cu al st syomer st emss for andPONs—business serv ices, in cludand ing det r esident ailed ial. descr Buipt siness ion s, cust rev iew om er quest s ions rt oeqen uirsu e re high con ercept band comp wid trheht han en sion resident and rial et en cust t ion, omand ers; ad in dit f act ional , bursiness esou r ces custf om or fu errts her m igh sttudy ev en . sell Covverag ser ices et oisr esident also extial end cued st om n oteronly s ont o t he new sam n et e wor inf rast k ing r uct concep ur e. PONs t s, butaralso e an t opt o old ical er ,access legacysolut ion tsyst hat em r eqs,uirpres ovid noinpgowa er m or and e rtealist hat ser ic vpict es ur me u ltof ip tleheSmall real- w Off orice/ ld nHom et w or e kOf ing fices en vir ( SOHOs) onm ent , sbuinsin wesses, hich pr of essionals and r esident ialoper cu st atomer e. Tools s f rom anda gu single id elines f iber. f orI nopt forim m izing at ion syst is t ran emspper or for t edmbet ance w een w illt hincr e cust ease om er pr odu and buctsin iv itess y an apdplicat im pr ion ov e ser effviciency, ices. Depend help ing ingt he onr teader he pr ov m ider, ake mor cu ste omer in t elligent s get ,eitcost h er- eff t heir icient ow n decisions sep arat e wfor avelengt t h eir net h or w ork a dat s. a st ream . Ty pically , r esid en t ial cust om er s' band w id t h requ irem en t s ar e w it hin dat a st r eam lim it s. SOHOs an d ot h er business cust omer s gener ally hav e high er ban dw idt h and ar e m or e sy m m et r ical t h an t h e asym m et r ical d at a st r eam used b y r esident ial cust om er s. Wh en bu ild ing PONs, business and r esident ial cu st omer r equir ement s are con sid er ed and ar e dif fer en t iat ed w it h diff erent SLAs ( Ser v ice Lev el Agr eem ent s) .

Optical Network Units and Optical Network Terminals ONUs ar e used t o agg regat e ONTs. ONTs ar e used at a business or r esident ial cu st omer t o t er min at e ser v ices f or deliv er y fr om t h e net w or k and/ or t r ansmission in t o t h e net w or k. Ty pically, up t o 32 ONTs can be serv ed fr om a sing le ONU. ONUs are t yp ically f ound in t he cent r al of fice and / or a r em ot e bu ild in g; in som e cases, t h ey can be p ole- and/ or pedest al- m ou nt ed wh en t h e equipm ent isTable t em perat u re- h ard en ed . • of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ethernet Passive Optical Networks By Cisco Systems, Inc.

Et h er et er: Passive Opt ical Net w or k s ( EPONs) p r ovide Et her net or I P dir ect ly ov er fib er w it h out t he Pubnlish Cisco Press int er venin g lay ers of ATM and SONET. By using Gigab it Et hern et ( GE) an d/ or 1 0 Gig abit Et her net Pub Dat e: Sep tem ber 1 1, 2 003 ( 10 GE) dir ect ly m app ed on t o DWD M, serv ice pr ov id er s can econ omically pr ov id e cust om er s I SBN: 1- 58 705 -1 19 -2 br oadb and and nar r ow band Et hern et / I P ser v ices. See t he sect ion " Passiv e Op t ical Net w or k s" t o Pages:t 11 28 learn abou PONs.

Metro Access Networks The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Today s en ent sedg or e ent tech er pnologies. rise and serv ice pr ovid er s h ave chan ged t he land scape for essent'ial anvir d onm cu t t ingt r adit ional net w ork s. Tr adit ional access net w ork s g en er ally hav e included ever yt h ing w it hin 40 k m of t he ser vice sw it ch ing cent er ( POP, TDM sw it ch , and so on) . Met r o access net w or k s now can com prCon ise cise m et ov r o er access cor e olog net wies or ks by tusing atked solutals ions. This s f rom v iew san ofdt echn essen ial t o int n etegr wor ingDWDM pr ofession at all levlet els, ent er pr ise serpert vice. pr ov iders hav e m et r o access net w ork s of 4 0 t o 80 k m and m et r o core nov iceant od ex net w or ks upw ar ds of 2 00 k m. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Bot h m et r o access net w or ks an d met r o cor e net w or ks let en t erp rise and serv ice pr ov id er s collect cust om Cov er erag t raf fic e ofancut d, tin ingsom edge e cases, t echn ologies pr ov id elik swe itopt ch in ical g an n et d wor roukt ing w and it hin st or t he age net w or k if r eq uir ed . I f gr oom in g and t r anspor t at ion are r equ ir ed, t hey are done in t he POP an d/ or Aut h ored Sy it stching ems, w or ldw int er off ice f acilitby y (Cisco I OF) sw cent er . ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Transparent Optical t echnologies. Mast er t he t erNetworks m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Cu st om needant d o ut rpdat anspar t ly ter r anspor t t h eir vices r usiv elyw or use anspar ent y, Com pleter e swwit ho h new ed en chapt s on secur it y ,ser st or age,unin opttical net k int rg, scalabilit opt n et wtor k s.book Typ ical st omer hav sensit iv e d ater a ence as w ell at t hare ey essen or t heir andical speed, h is is a cu com plet e san d uept o- d at r ef t o as t het rt af opfic icst ht hat t ial t o all cust er sgdpon't w ant t o r efor m at in t oofex in gise. legacy or n ew er nex t - gener at ion sy st em s. net wom or kin rof essionals, r egar dless existpert Tr anspar ent op t ical net w or ks essen t ially allow cust om er s t o p lu g t heir opt ical signals in t o Reader sw ill obt ainneit a gher reatcar er eunab der st an of LAN andical WAN argt icu lar lyique. the t r anspon ders t hat out nording af fect t h e opt linen et r atweorork ing, fr ampin t echn har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov Tr anspar ent op t ical t r anspond er s can be f ound in access, m et r o, an d t ran sp ort net w or k s.ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Transport Networks syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Tr wor k s pr prov oveide t ical inhelp t er conn bet wmeen et roe access net,wcost or ks- eff anicient d met r o pr anspor odu ct ivtitnyetan d im eff op iciency, ing tect he ion r eader akemmor in t elligent core net w for ork s. Tr anspor t net decisions t h eir net w ork s. w ork s u se lon g- hau l, ex t end ed long- haul, an d u lt ra- lon g- hau l equipm ent t o g ive ent er pr ise and ser v ice pr ovider s t r anspor t pipes f or all ser v ices ov er dist ances of 80 t o 200 k m . OTNs em ploy engin eer ed I TU and / or Telcor dia ( BellCor e) sy st em s t o t r anspor t gr oom ed or sw it ched TDM and/ or dat a t raf fic t o and f rom ot her sw it ch in g cent er s and I OF, SONET, SDH, and PDH syst em s ar e used in t r anspor t n et wor k s.

Long-Haul Networks Bein g able t o t ran sp or t circuit and dat a ser v ices b et w een lar ge m et r o access n et w or k s is hig hly desirab le. Long- haul ( LH) n et wor k s pr ov ide t r anspor t at ion circuit and pack et - aggr egat ed and gr oom ed ser vices bet w een cen t ral off ices and b et w een cent r al of fices and ser v ice POPs. This is accom p lished w it h t he use of WD M an d D WDM laser s, filt ers, an d op t ical am plifiers. Pack et and circuit t r aff ic are gr oomed in sw it ching and I OF cent er s and t hen ar e t ight ly packed int o opt ical • Table of Content s pay loads t o be op t ically t r ansp ort ed up war ds of 600 k m t o ot her sw it ch in g and I OF cen t er s or •cust om er s. I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

OpCisco t ical Systems, lin e rat es f or long - haul net w ork s ar e g en er ally OC- 4 8/ STM- 1 6 and OC- 1 92/ STM- 64. By Inc. Dist ances and capacit y ar e gov er n ed by t he t y pe of laser, fiber , and opt ical spacing . Using b ack t o- bPub ack elect r ical t r anspon ders, op t ical sig nals can b e elect r ically r egenerat ed, r et im ed, an d lish er: Cisco Press r ef r amed t o allow sh aping of t he op t ical sig nal, aiding in allowin g t he opt ical sign al t o b e Pub Dat e: Sep tem ber 1 1, 2 003 ext end ed . Figur e 23 - 1 sh ows an ex am ple of LHN. I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 2 3 -1 . M e t r o Ed ge, M et r o Cor e , Lon g-H au l, an d Ex t e nde d LongHa u l O pt ica l Ne t w or k s The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.[ View full size im age] Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Extended Long-Haul Networks This is a r elat iv ely n ew net w or k t opology t hat pr ovides a solu t ion f or serv ice pr ov id er s b et w een long- haul and ult r a- long- h aul n et w or k s. Using a h yb r id t echniq ue of ED FA and Ram an am plificat ion, d ist an ces of 6 00 t o 2 500 k m can be achieved. Ex t en ded lon g- hau l ( ELH) n et w or k s cost - ef fect ively allow opt ical sign als t o t r anspor t pack et and cir cuit t r aff ic wit h out hav ing t o emp loy opt ical r egenerat ion f or up t o 2500 k m ( see Figur e 23 - 1) . •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ultra-Long-Haul Networks By Cisco Systems, Inc.

Ult r a- long- hau l ( ULH) n et wor k s ar e used for t r af fic r equir ing t r anspor t ov er dist ances gr eat er Press t hanPub6lish 00er: kmCisco . ULH net w or ks can also be u sed for t he sam e ar ea as LH and ELH net w or k s. Ev en Pub Dat e: Sep tem 1, ed 2 003 w it h over lap, ULHberis 1pr omin ant ly used for d ist an ces in t he t housand s of kilom et er s, includ in g I SBN: 158 705 -1 19 -2 subt er r anean or oceanic op t ical net w or ks. Ter rest r ial opt ical n et w or k s use ULH n et wor k s w her e t he use of elect Pages: 11 28 r ical r egener at or s m akes deploy m en t econom ically challenging . Usu ally AON t echnology is used , allowin g op t ical sig nals t o not requ ir e elect r ical r eg en er at ion , r e- t im ing , and r esh aping. Phot onic t ran sp or t sy st em s r eq uir e no opt oelect r onic ( OEO) r eg en er at ion. For ex am ple, m any elect r ical r eg en er at or s an d ad d/ dr op m ult iplexer s ( ADMs) ar e r eq uir ed t o pr ov id e ULH t r anspor t at ion . Oper at ional an d cap it al saving s can be achieved w it hout The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t he use of elect r ical r egener at or s and add/ dr op m u lt ip lex ers. ULH pr ovid es t he sam e lev el of essent ial an d cu t t ing- edg e t ech nologies. r est or at ion, pr ovisioning , and per for m ance as t r adit ional SONET/ SD H. Figur e 23 - 2 sh ows t he com plexit y r equir ed for ULH opt ical net w or ks. By u sin g Ram an op t ical Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom am plificat ion, p rov ider s can r edu ce t he am ount of elect r ical regener at ion and eq uipm ent . Th is nov ice t o ex pert . point is im por t ant for operat ion al and m aint enance concer ns, par t icular ly wit h sub t er r anean or oceanNew ic optchapt ical net or k s. cov erag e of im por t ant t opics like VoI P and EAP er swinclude Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by CiscoFigu Sy st ems, r e 2w 3 or -2ldw . Ul idet rleader a -Loningnet Ha w or ulking N et f orwt or he kI n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Gigabit and 10 Gigabit Ethernet Optical Networks

Dir ect ly m app ing GE and 10 GE t o t h e opt ical net w or k can cost - eff ect iv ely meet cust om er br oadb and band w idt h r eq uirem ent s t od ay and in t he f ut ur e. Dir ect I P ov er phot onics does not r eq uir e nonb lock ing cross- connect s t h at r equir e opt ical p ort scalab ilit y . GE an d 1 0GE dev ices can use Layer 1, 2, an d 3 f unct ionalit ies, increasing ser v ice f unct ionalit y , per for m ance, and scalab ilit y . GE an d 1 0GE opt ical n et w or k s can be connect ed b y high - perf or m ance rou t ers t o pr ov ide scalab ilit y , r est orat ion , and bit - r at e t ran sp arency . Packet net w or ks h ave no b ound aries for bot h t he ser vice and p hy sical lay er . •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Generalized Multiprotocol Label Switching Gener alized Mu lt ipr ot ocol Lab el Sw it ch in g ( GM PLS) , as p r oposed by t he I nt er net Engin eer in g Task Force ( I ETF) , w ill allow r out er s, sw it ch es ( packet and cir cuit ) , D WDM net w ork s, ADMs, ph ot onic cr oss- connect s ( PXCs) , and opt ical cr oss- connect s ( OXCs) t o dy nam ically pr ov ision •r esour ces. GMPLS Table ofwContent ill alsos pr ov id e pr ot ect ion an d r est orat ion t o t he p rov isioned serv ices. •

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IGMPLS nt e rn et wcan or k ing Te chnologie s H alay, ndbook , Four ion en t ed m od el used t o pr ovid e t he cont r ol plane f or su ppor t an over peer , anthd Edit au gm TDM net w or ks ( su ch as PD H, SDH/ SONET, and G. 70 9) , DW DM net w ork s, and ph ot onic By Cisco Systems, Inc. sw it ch in g. Tim ing, sig naling, and rou t ing ar e all par t of t hese mod els. lish er: Cisco Press ThePub f ollow in g sect ions cover on ly high - lev el aspect s of GMPLS. For f ur t her in for m at ion, r eview Pub Sepdtem ber 1 1, 2 003 RFCs 3 Dat 031e: an 2 026 and v isit t he I ETF for um . I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Label Switch Routers RFC 303 1 d oes not recognize p ack et an d cell bou ndar ies, w hich p recludes it fr om f orw ar ding dat a der ived fr om t h e infor m at ion in t he pack et or cell header s. Label Sw it ch Rout er s ( LSRs) , The u pdat edit ion of et t he b estcells, - selling all-Th in-e one neting w ork ing ras ef erence coversu age of t w hich car red y t hese pack s and can. follow LSRs, d ef inedp rov by tides h e I ETF, ppor essent ial an d cu t t ingedg e t ech nologies. for w ar ding decision s based on t im e slot s, w avelen gt h s, and opt ical por t s: Con cise ov eri tvch iew s of ab t echn essen ial t o nI nett er wor k ingt hpratofession als at allet levb els, f rom P ack e t Sw - Cap le ( olog P SC)iesi nt e rfatces— f aces r ecognize p ack oundar ies nov ice t o ex pert . and can for w ar d d at a b ased on t he cont ent of t he p acket h ead er . Ex amp les in clud e int er faces on rou t er s t hat f or w ard dat a based on t he header 's con t en t an d in t er f aces on New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP r out er s t hat for w ar d dat a b ased on t he cont en t of t h e m ult ipr ot ocol label sw it ch in g ( MPLS) " shim " h ead er . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age La y er 2 Sw it ch- Ca pa bl e ( L2 SC) in t er fa ces— I n t er f aces t h at r ecognize f ram e/ cell Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . bou ndar ies and can f or w ard dat a based on t h e cont ent of t he f ram e/ cell header. Ex amp les in gt erTech f aces on Et hern et book br idges t h at or it wion ard, dat based on t h e cont ent of tthe I n t erninclude et w or k in nologies Hand , Four t h fEd is aacom pr ehensive refer ence hatMAC header an d in t er f aces on ATMLSRs t hat f orw ar d dat a based on t he ATM VPI / VCI . enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Tim e - D i vi si on Mul t ip le xi ng ( TD M) Ca pa bl e in t er fa ces— I n t er f aces t h at f or war d dat a indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . based on t h e dat a' s t im e slot in a r epeat ing cycle. Ex am ples in clu de SDH/ SONET cr ossCom plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, connect s ( XCs) , t er m inal m ult ip lex er s ( TMs) , and ADMs. Ot her exam ples include in t erf aces and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all pr ov iding G. 70 9 TD M capab ilit ies ( t h e " digit al wr app er " ) and PDH in t erf aces. net w or kin g p rof essionals, r egar dless of ex pert ise. La m bda Sw i t ch- Ca pa ble ( LSC) i nt e rf aces— I n t er f aces t h at f or war d dat a based on t h e Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e w av elengt h on w hich t he d at a is r eceiv ed . An ex am ple of such an in t er f ace is a Phot on ic har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Cr oss- Connect ( PXC) or Opt ical Cr oss- Conn ect ( OXC) t hat can op er at e at t he lev el of an a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions indiv idual w avelengt h . Add it ion al exam ples includ e PXC in t er f aces t h at can oper at e at t he t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . level of a gr oup of w avelengt h s—a w av eb and and G. 709 int er faces pr ov iding opt ical Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy capabilit ies. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Fibe r Sw it ch - Capa bl e ( FSC) i nt e rfa ces— For w ar d d at a b ased on t he d at a's p osit ion in pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient ph ysical ( r eal- w or ld) sp ace. An ex amp le of su ch an int er face is a PXC or OXC t hat can decisions for t h eir net w ork s. oper at e at t he level of a sin gle f ib er or m ult iple f ib er s. A cir cu it can be est ablish ed on ly bet w een or t hr ou gh in t erf aces of t he sam e t yp e. Depending on t he par t icu lar t ech nology b eing u sed for each in t erf ace, diff er ent cir cuit n am es can be u sed , such as SDH cir cuit , op t ical t r ail, and lig ht pat h. I n t h e cont ext of GMPLS, all t h ese circuit s are r ef erenced by a com m on nam e: Lab el- Sw it ched Pat h ( LSP) .

The con cept of nest ed LSPs ( LSPs w it hin LSPs) , alr eady av ailable in t rad it ional MPLS, facilit at es bu ild in g a f orw ar ding h ier ar ch y—a hier archy of LSPs. This hier arch y of LSPs can occur on t he sam e int erf ace or bet w een dif fer en t int er f aces. For exam ple, a hier ar chy can be bu ilt if an int er face can mu lt iplex sev er al LSPs fr om t he sam e t ech nology ( lay er ) —t hat is, a lower - or der SDH/ SONET LSP ( VC- 1 2) nest ed in a high er - or der SDH/ SONET LSP ( VC- 4) . Sev er al lev els of signal ( LSP) n est ing ar e d ef ined in t he SDH/ SONET mu lt iplex ing hier archy . •The n est ing can Tablealso of Content occu r sbet w een int er faces. At t h e t op of t he h ier ar ch y ar e FSC int er faces, •follow ed by LSC I ndexint er faces, TDM in t erf aces, L2SC in t erf aces, an d PSC int er faces. This w ay , an t hat stkart and ends son PSC ,inFour t er th f ace ILSP nt e rn et w or ingsTe chnologie H aa ndbook Editcan ion be n est ed ( w it h ot her LSPs) in an LSP t hat st art s and ends on an L2SC in t erf ace. This LSP, in t u rn , can b e nest ed ( w it h ot her LSPs) in an LSP t h at By Cisco Systems, Inc. st ar t s and ends on a TDM int erf ace. I n t u rn , t his LSP can be n est ed ( w it h ot h er LSPs) in an LSP t hat st ar t s and ends on an LSC int er face, w hich, in t u rn , can b e nest ed ( w it h ot her LSPs) in an lish er: Cisco Press LSPPub t hat st art s and ends on an FSC in t er f ace. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 11 28 Link Pages: Management Protocol

GMPLS is b ased pr im arily on ext end ed r out in g an d sign alin g p r ot ocols u sin g I Pv 4 ( and I Pv6 in t he fut ur e) for addr essing . But LSPs n eed t o consider f ram ing , pr ot ect ion sw it ching, and so on. Thu s, Link Managem en t Pr ot ocol ( LMP) is n eeded for sign alin g. LMP is g en er ally considered The edit ion t he b est -rou selling in- one net.wDiscov ork ingery r ef erence p rov w heruepdat shored t est pat h of fir st ( SPF) t ing allis insuf ficient of resour ce ides st at ecover and age dom of ain essent ial an d cu t t ingedg e t ech nologies. t opolog y ar e dependent on t hese rou t ing pr ot ocols. GMPLS cont r ol and d at a plan es are sep arat ed , so LMP is r equir ed t o pr ov ide k now led ge b et w een TE link s and neigh bor ing nodes. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom LMP pr ov ides m echan ism s t o m ain t ain con t rol channel con nect iv it y ( I P cont r ol ch annel nov ice t o ex pert . m aint enance) , v erif y t he p hy sical conn ect iv it y of t he d at a- bear in g lin ks ( lin k ver ificat ion) , corr elat e t he lin k pr oper t y inf orm at ion ( link pr op er t y cor relat ion) , and m anage link failur es ( fau lt New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP localizat ion and f ault n ot ificat ion) . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age The m aj or it y of con t r ol chann els f or GMPLS r equir e I P t o t r anspor t t he signaling and r out in g pr ot ocols suchby asCisco LMP) .Sy GMPLS notide specif y how t hiswis one.f or That Aut h (ored st ems,does w or ldw leader in net ordking t heisI nup t ertnoett he . m anuf act ur er. Cont r ol chan nels for GMPLS can b e eit h er in - band or out - of - band . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat LMP pr ovnet ides cont el m anagem en t (and m ultan ip le wav elenengtt hs bet w een opt chork es)ing and enables w or kin rgolp rchann ofessionals t o un derst d im plem cont em por ar y ical int ersw netitw link pr op er t y cor r elat ion. Link conn ect iv it y ver ificat ion and fault m anagem ent can also be t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing considered fornLMP ar e opt aserper indu st ry . Lear howbut t o incor porional at e int net IwETF. or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all LMP Control net w orControl kin g p rofChannel essionals,and r egar dless of Channel ex pert ise.Management Reader s twr ol ill Chan obt ain reat an er dunCont der st anCh ding of LAN and WAN et w or ar k ing, p ar tt o icuest larab ly lish t h e and LMP Con nela (gCC) r ol annel Managem en t (nCCM) e used har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov m aint ain nodal con t r ol chann els. CC is u sed t o ex ch ange MPLS con t rol plane in for m at ion.ided on a b r toad ang ealin of g, intan egrd al sy st em agement s and servcan ices, cluded ingb et det descr ipt ion s, CCs rev iew Rou ing, r sign link man beinshar wailed een nodes. These canquest be ions tdy o nam en suicreorcon cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy st at ically con figu r ed . Each CC is allow ed t o n eg ot iat e and m aint ain con nect iv it y. u sing Cov erag e is ext endhed only newb en et wor ing s, but also alive t o oldfor er , chan legacy t he hello pr otalso ocol. The ellon ot p r ot ocolt ocan con sidk er edconcep lig ht wteig ht keepnel syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent in w hich failur es allow ing lin k- st at e adjacencies. LMP r equir es t hat one cont rol ch annel alw ay ssbe pr essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease avof ailab le. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions forest hand/ eir net ork s.iat es t he ex ch ange of con t rol- p lane inf orm at ion . Fau lt m anag em ent , CCM m anag or wnegot link pr ov ision in g, p at h man agem en t , and label d ist r ibut ion ar e shar ed b et ween t he link w it h in one or m ore b idir ect ional con t rol ch annels. Pr ovisioning a con t rol channel is done eit her st at ically or aut om at ically , w it h CCM pr ov ision in g t he I P ad dr ess on t h e far end of t h e cont r ol chann el. CCM uses sig naling pr ot ocols, such as RSVP- TE ( RFC 32 09) , and t r aff ic en gineering ext ensions of pr ot ocols, such as OSPF- TE and I S- I S- TE, f or link dist r ibut ion and pat h

m anagem ent , r esp ect iv ely .

Link Property LMP also def in es lin k pr oper t y corr elat ion, w hich is used t o agg regat e mu lt iple ( dat a) link s. Com pon en t link s ar e bu ndled and corr elat ed , exchan ged, or mod ified. Lin k pr oper t y ( LP) •corr elat ion can Table Content beofset up wshen t h e link is av ailab le, but not dur ing t h e ver ificat ion st ag e. •

I ndex

nonint er faces, along, Four w it hthI P host IPSC nt e rnand et w or k ingPSC Te chnologie s H a ndbook Edit ion s and r out er s, can r eadily be id en t ified b y I P add resses. Wit h I P r out in g p r ot ocols, r out es f or I P d at agr am s can b e r out ed v ia SPF alg or it h m . By Cisco Systems, Inc. Con ver sely , non - PSC cir cu it s can f ind r out es using a CSPF algor it hm . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

User-to-Network Interface I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

What is signif icant f or GMPLS is t h at exist ing I P r out in g pr ot ocols can be u sed for non- PSC lay er s. Rich developm ent in t h ese pr ot ocols' fun ct ion alit y, su ch as int rad omain ( link - st at e) r out ing and int er dom ain ( policy) r out ing, can b e used . This is of p ar t icu lar in t erest f or pr ov iders in an ov er lay mod el. Th e non - PSC lay er can b e aut on omou s. I n t erd omain r out ing ( such as BGP) can be used t o r out e in for m at ion ov er aut on om ous net w or k s. This obv iously has a hug e benefit The pdat of tpr heov b iders. est - selling netint w rork ing ain r ef erence p rovprides cover t o exuist in ged in tedit erd ion omain Segmallentinatone ion of adom ar eas can ov ide r outage ing of essent ial an d cu t t ingedg e t ech nologies. dom ains b y using I S- I S or OSPF ( lin k- st at e) rou t ing for TE. User - t o- Net w ork I nt er face ( UNI ) is t he link b et w een t he GMPLS n ode and a GMPLS LSR ( net w or k Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom side) . Net w ork - t o- Net w or k I nt erf ace ( NNI ) is t he in t erf ace bet w een t w o n et w or k LSRs. The nov ice t o ex pert . hist or y of GMPLS is one t hat con sid er ed UNI an d NNI at t h e sam e t im e an d cr eat ed a dist in ct ion for GMPLS. This sect ion does n ot r eview t h is dist in ct ion ; it only poin t s out t hat t her e is one. Th e New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP OI F UNI specif icat ion is t he client sp ecificat ion for SD H/ SONET, w h ich is designed for an ov erlay m odel. Cuerag rr ent t het ing OI Fedge UNI dt echn oes not su ppor G. 709 al Wr apper otage her phot onic Cov e ly of, cut ologies lik et opt ical Dig n etitwor k ing and or st or net w or k m odels. GMPLS assu mes t h at OI F UNI is a su bset of GMPLS. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

G.ASON I TU' s G. ASON ( Aut om at ic Sw it ched Opt ical Net w ork s) u ses t r anspor t net w or k ar ch it ect ur e r ecom m en dat ions ( G. 803 , G. 80 5, G. 8 72, an d I . 32 6) , am on g ot hers. •G. ASON usesTable of Content a cont r ol p lans e t o con figur e sw it ched an d sof t p er m anent connect ions at t he •t r anspor t lay Ier ndex . Reconfigu r at ion f or connect ions or t he abilit y t o m odify conn ect ions w hile Ipr ntov e rniding et w orrkest ing or Teat chnologie s H a ndbook , Four Edit ion ion is requ ired. For spthecific t echn ical d et ails on G. ASON, ref er t o I TU' s T- RECG. 80 80 r ecom m en dat ion. By Cisco Systems, Inc.

G. ASON is essen t ially t he ar chit ect u r e and r eq uirem ent s f or t he con t r ol plane com pon en t s in lish er: Cisco Press SDHPuband PDH t o allow t r anspor t net w ork resour ces t o set up , m aint ain, an d release conn ect ions Pub Dat e: Sep 1, 2signaling 003 for G. ASON t o tem perber for1m an d conn ect ion ser v ices f or t he cont rol plane b et w een t he t h ree I SBN: 158 705 -1 19 -2 dist inct p lanes—con t rol, man agement , and t r anspor t . Call cont r ol and conn ect ion con t r ol ar e pr ov ided Pages: v ia11sign 28 alin g, w her e t he con t r ol plane set s u p an d t ear s d own t h e connect ion( s) . Rest or at ion is also in clud ed . I nt er act ion ( f ault , QoS, and so on) bet w een t h e t r anspor t p lan e and cont r ol p lan e allows t he t r anspor t plane t o upd at e t h e con nect ion 's st at u s t o t he cont r ol p lane as r equir ed. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Control Plane

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The con t rol plane p er f orm s link st at u s ( capacit y, failur e) t o supp ort connect ion set up / t ear d own nov ice t o ex pert . and r est or at ion. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Dom ains ar e u sed t o allow su bdiv ision of cont r ol plan es. I f desired, t ran sp or t plan es can also be subd ivided int o t he sam e planes. Sub divid in g dom ains let s t hem b e adm inist er ed—som et hing Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age high ly desir able f or serv ice pr ovid er s w ho w ant geogr aphic or eq uipm ent diver sit y. UNI is t h e r ef erence p oin t by b etCisco w eenSy t he adm inist at ive and d king u ser .f or E- NNI hen et r efer Aut h ored st ems, w orrldw idepoint leader in an neten w or t he Iis n t ter . en ce point bet w een dom ains. I - NNI is t he r ef erence p oin t b et w een r ou t ing areas an d set s of cont r ol com ponent e apnologies plicab le.Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat I n t ern et w orskw inhgerTech enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Policies ar e used acr var r efer ce point s ( UNI NNI , andused E- NNI an d ' are uw niqu to t echnologies. Mast eross t het he t er m s,ious con cep t s,ent echn ologies, an, dI - devices in )t oday s net orkeing tindu hemst. Table 2 31 sh ows var ious p olicies applied t o call cont r ol, conn ect ion con t r ol, and r out ing ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .. Add ressin v ar iou it iesed in chapt a G. ASON t rolitplane n eeded for net muwltor iple it ies, Com plet e gw fitor h new ansdent u pdat er s oncon secur y , st orisage, opt ical k inent g, scalabilit y, includin g conn ect ion cont r ol, SNNP, r out ing ar ea, calling / called par t y call cont r ol, net w ort kialcall and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t o all cont ol,kin and t r anspor tr. egar Ad drdless essing it iesise. can be uniqu ely assigned by t h e G. ASON an d can net wror g pUNI rof essionals, of en extpert t hen be u sed globally an d/ or w it hin an ar ea. Resou rce discover y is don e st at ically or aut om at acrain ossa UNI , E, and I -ding NNI fof unct ions. Reader s ically w ill obt g reat erNNI un der st an LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Tabiclepict 2 ur 3 -e1of. Pol icy Fun ions syst em s, pr ovid in g a m or e r ealist t he realw or ldct n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

•

UNI

I -N NI

E- N N I

Call cont rol

Yes

—

Yes

Resour ce discov ery

Yes

Yes

Yes

Con nect ion cont r ol

Yes

Yes

Yes

Con nect ion select ion Table of Content s

Yes

Yes

Yes

—

Yes

Yes

• Con nect ion Ir ndex out ing

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

As oper at ing exp er ience is gained w it h em ploy ing cu r rent t r anspor t net w ork t echn olog ies an d newPub t echn lish er:olog Cisco ies Press ev olve ( su ch as v ar iable- size p ack et s, high - sp eed t r anspor t n et wor k s, and ASON) t hese ecomm at ion s need t o be en hanced, or n ew r ecom m en dat ions n eed t o b e Pub ,Dat e: Seprtem ber 1 1,end 2 003 dev elop ed , 1in58close cooperat ion w it h t he st an dar dizat ion act iv it ies on t ran sp ort net w or k syst em s I SBN: 705 -1 19 -2 and equip ment . Enh ancem ent s are also need ed t o t he r equir ement s for t he m anagem ent Pages: 11 28 capabilit ies of t r anspor t n et w or k s. Mor eov er, r eq uirem ent s f or new t r an sp ort net w or k int er faces need t o be st u died.

Unified Control Plane The u pdat ed edit ion of t he b est - selling

all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Ther e ar e sev eral appr oaches t o con t r olling t h e opt ical cont r ol p lan e. One com m on t rait is t hat dir ect sig naling is r eq uir ed . Unified Cont r ol Plane ( UCP) is one t echn ique t hat let s OTNs sig nal Con cise ov erThe v iewbenefit s of t echn olog ies essen t ial k ing prh ofession lev bels, f rom indiv idual nodes. of UCP is t hat ban dwt oidtnhet(wor t y pically igh bandals w idat t h)allcan e en abled nov ice t o ex pert . m or e cost - ef fect iv ely. Ser v ice p rov ider s can u se UCP. Most , if not all, developed UCP can be defin ed as p rop riet ar y . This d oes n ot m ean t hat it cannot or w ill not int er oper at e w it h ot her UCP New er s include cov erag e of im por t ant t opics like VoI P and EAP im plem entchapt at ion s. e oft hat cut com t ing pr edge echnessing ologies, rlik e ing opt,ical wor k ingprand st or age UCP isCov soferag t w are ises taddr out andn et signaling ot ocols. I t r uns on I P r out er s ( such as GSR and 760 0) and opt ical net w or k elem ent s ( such as 15 454 , 15 600 , 15 801, Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . and 15 200 ) w her e cont r ol f unct ions are unif ied across t h e dispar at e t echnology lay er s, mak ing cont r ol ind ep en dent of t ran spor t . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Dif ferent m odels ar e defined by t he ind ust ry . Th e ov er lay m odel and p eer m odel ar e t h e m ost t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing pop ular . The p eer m odel h as ju st one com m on con t r ol plane f or Layer 3 and opt ical n et wor k s. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Overlay net w or kinModel g p rof essionals, r egar dless of ex pert ise. Reader sw ill mod obt ain a g reat er der st an ding and WAN n ettw p arand t icuone lar lyf or t h et h e The ov er lay el defines t w ounadm inist rat iv eofdLAN omain s—on e for heorIkPing, lay er har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided opt ical lay er. Each lay er uses it s ow n con t r ol plane an d Opt ical User Net w or k I nt er face ( OUNIon ) a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o com m un icat e w it h t he ot her ( see Figur e 23 - 3) . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and f or opt im izing syst em Pl per forem ance w ill incr ease Figu r e gu 2 id 3 elines -3 . Com mon Cont r ol an pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Peer Model Sever al Op t ical Cont r ol Plan e ( OCP) init iat iv es ar e u nder w ay w it hin t he t elecom indu st ry . Th e end goal of all t hese st an dar ds b odies' act iv it ies is t o pr ov id e aut om at ed en d- t o- end op t ical net w or k pr ov isionin g w it h t he addit ion of m esh r est or at ion. Th e follow ing ar e br ief d escr ip t ions of t he st an dar ds b odies and t heir OCP init iat iv es' focu s: • •

Table of Content s I ndex

The Opt ical I nt er net w ork ing For um ( OI F) is w or k ing on an im plem en t at ion agr eem en t f or a UNI bet w een opt ical n et w or k clouds and client s.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

The I ETF is w ork ing on a st and ar d t h at ex t ends t he capabilit ies of MPLS t o cont r ol aver: elengt an d cir cu it s in addit ion t o p ack et s. Pubwlish Cisco hPress Pub Dat e: Sep tem ber 1 1, 2 003

The I TU is w or k ing on a st andar d for opt ical cont r ol. I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Overlay Network Configuration For an over lay net w or k t hat not ev er yon e need s t o r ou t e, t hey do need t o be ab le t o signal t he connect ion requ est s. Ty pically , an ov er lay m odel is u sed w hen t he op t ical net w ork ser vice The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of pr ov ider and t he user of t he f acilit y r equir e no t r ust . O- UNI def in es opt ical int er face essent ial an d cu t t ing- edg e t ech nologies. r eq uir em ent s f or t h is int eract ion. GMPLS r out esov clien r equest s w itolog hin ties he essen opt ical st at ically or dy nam ovid in g t he Con cise er v tiew s of t echn t ialnet t ownor etk, wor k ing pr ofession alsically at allprlev els, f rom ser v ice. Rout ing inf orm at ion st ay s in t h e opt ical b ack bon e and is not shar ed w it h subnet w or k s, nov ice t o ex pert . because it is u nnecessar y t o d o so. Pack et client s use t he op t ical net w ork as point - t o- point I P link s. New For TDM s, opt ical e fix idt h pat s. P and EAP chaptclient er s include covLSPs erag earof imed por- ban t antdw t opics likeh VoI Wit h tCov he erag ov er e layofmod y can b e anlikissue t ical net w ork cap acit y g row s. D ue t o cut tel, ing scalabilit edge t echn ologies e optas icalt he n etop wor k ing and st or age t he lack of r out in g in for m at ion, clien t s cannot select t h e cor r ect r out er or ligh t p at h. I n t oday 's net w or ks, t his issu e does appear o be if icant Th is war r ant s fur st n u et dy. as t he opt ical Aut h ored by Cisco Synot st ems, w ortldw idesign leader in. net w or king f or t het hIer n t er net w or k gr ow s. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Peer Model indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, The er lay t mod el fails pr ovid alerrou t es.t oTht he is is t he ice w e pessen ay fort ial h avin g and ov speed, h is book is at ocom pletee en andd tuo-p-end t o- dopt at eimr ef ence t op icsptrhat are t o all adm inist r at ive con st r aint s. Th e peer m odel add resses t h is pr oblem and is m or e suit able f or cases net w or kin g p rof essionals, r egar dless of ex pert ise. in w hich such adm inist rat iv e m easu r es n eed not be ob ser ved. Use a sin gle cont r ol plan e for all dev icess( w such asain r out s and icalstsw ches)of and UNI , as nim in MPLS. Reader ill obt a er g reat er opt un der anitding LANno and WAN etplied w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tFull o en su re con ceptModel comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Peering Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich A f ull p eer ing m odel has a sin gle I GP in st ance for t he ent ir e net w or k, inclu ding I P r out er s and pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease opt ical sw it ches. There are t wo possible imp lem ent at ion s: pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Si ngl e- ar e a im pl em e nt a t ion— Com mon I GP. Use a flat n et wor k or gan izat ion w it h a com mon I GP ru nning in I P and op t ical net w ork s. Mu lt i ar ea sol ut i on— I GP w it h su m mar izat ion. Use hier archical r out in g w it h in I GP w it h m ult iple ar eas and sum m arizat ion of r eachab ilit y and resour ce infor m at ion.

Filtered-Pair Model and Augmented Model Filt er ed- pair an d augm ent ed mod els d o n ot shar e t op olog y infor m at ion. The opt ical cont rol plane and I P/ r out er cont r ol p lan es are separ at ed and hav e no kn ow ledg e of each ot h er . Usin g t his m odel allow s I P/ rou t ers t o learn ab out p eer s and associat ed opt ical endp oint s b y sh ar in g or exchan ging inf ormofatContent ion w its h each ot her . • Table •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Optical Control Plane User Network Interface The Op t ical Con t rol Plane User Net w or k I nt erf ace ( OCP- UNI ) is a set of soft w ar e f unct ions b ased on an em er ging st andar ds pr ot ocol t hat let s sy st ems in it iat e and comp let e cir cuit an d lig ht - pat h connect ions acr oss opt ical net w or ks. Th ese elem ent s may in clu de ADMs, cr oss- con nect s, op t ical •sw it ch es, r out Table Content er s, ofand ATMs sw it ches. •

I ndex

IFor nt e rn et w orple, k ingCisco's Te chnologie sH ndbook thion Editof iont he OCP- UNI allow s cust om er s t o ex t en d " A- t o- Z" exam 1 545 4a im p lem, Four ent at pr ov isionin g b ey ond t h e dom ain of a single ONS 154 54 SDCC- con nect ed net w or k w it hou t By Cisco Systems, Inc. r eq uir ing t he u se of a high er - lay er man agem en t sy st em t o " bin d" t he pat h b et w een subn et w or k s. This f eat u r e is sim ilar t o t he ONS 154 54' s A- t o- Z pr ov isioning f eat ur e but includes Pub lish er: Cisco Press a n um ber of enhan cem ent s. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN:ov1-er 58 705 19 -2 is u sed t o in vok e ser v ices t h at op t ical net w ork s of fer t o client s. Use of t he Signaling t he-1UNI UNI int Pages: erf ace 11 28 r eq uir es

Defin in g t he serv ices of fer ed ov er t he UNI Defin in g how t h ese serv ices ar e in vok ed The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essentDefin ial an t t ingedg e tm ech nologies. indg cu t he signaling ech anism for in vok ing t he ser vices I n t he UNI 1. 0 imp lem ent at ion , t hese ser v ices ar e used t o inv ok e connect ion cr eat ion , delet ion, cise ov ery v. iew t echn olog ies essen t tial o n etmwor levur els, and stCon at us in quir To sp rof ovide t hese ser vices, he t UNI ustk ing of ferprtofession h e followals ingatprall oced es:f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP N e ig hbor di scov er y— Allow s a client syst em t o in for m t h e net w or k elem en t of it s Cov eragivit e of connect y . cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Autrv h ored Cisco ems,s wt horeldw king hemIat n tion er nab et .out available Se ice dby iscov e rySy —stAllow netide w orleader k elemin entnet s tw o or con veyf or inftor ser v ices t o t he client sy st em s. Ser vice discover y uses t he in for m at ion f r om neighb or I n t erndiscover et w or k iny gt oTech Hand book , Four ion , issyastcom pr ehensive refer ence t hat connologies vey ser v ice in for m at ion ttoh tEd h eitclient ems. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er rol t he cha t er mnne s, con t echn ologies, d chan devices in t odays' st hnet w ork ing Si gna li ng cont l mcep ai ntt s, e na nce— A contan r ol nel used t hat connect e client sid e indu stand ry . Lear n how incor t h e net w orkt osid e. por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, Ad dretss h isrebook sol utisi on— a comAllow plet es an clien d ut ps ttoo-obt d atain e r ef opt er ical encenet t owt or hekt op point ics st hat of atare t achm essen en t ,ial t o all net w or because kin g p rof t her essionals, e is a separ r egar at ion dless bet ofwex een pert t he ise. t wo ent it ies. Regist rat ion ( a requ est t o associat e client lay er ad dr esses w it h an op t ical net w ork point of at t achm en t ) an d q uer y ( obt ainin g Reader s wnet ill wobt ainpoint a g reat ert achm un derent st anad ding of fLAN n et w or kiting, p aress) t icu lar t h e ed by t he ork - of - at dr ess or a and rem WAN ot e clien t by s addr ar ly e cover har dwt his ar e,ser prvice. ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en UNI OCPsu re also con cept in clud comp es feat r ehur enes sion t hat and autr et om enatt ion, e op and t ical ad net dit wional or ks acr r esou ossr ces var ious f or fueq rt uipm her stent udy - based . Covwerag net or k eelem is also ent s. extThese end edfeat n otu only res art o e new t h e aut n eto-wor d iscover k ing concep y of adj t s,acen but t also net wt or o old k elem er , legacy ent s an d systom aut emat s,ed pr addr ovid in ess g ar eg m ist or e r atr ealist ion wic it hpict t hese ur e au of ttohediscover real- w or edldnet n etwwororkkelem ing en ent virs onm or net entwsork in s. w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Client equest ices of t he opt wor k umsin g UNI . UNI sig- naling pr odu ctnet iv itwyork ansdr im pr ov eserv eff iciency, help ingical t hen et r eader ake mor esignaling in t elligent , cost eff icient m essages for ar et ht reir anspor ed s. over I P con t rol ch annels—in- ban d ( I B) or out - of- ban d ( OB) . Var ious decisions net wtork pr ot ocols, su ch as LDP and RSVP- TE, allow UNI sign alin g, b ut ar e n ot t h e only solut ions.

Optical Control Plane Optical Network-to-Network Interface OCP is a mod ular soft w ar e f eat u r e set t hat pr ovid es fun ct ion s r elat ed t o n et w or k ing con t r ol •capabilit ies, su Table ch of asContent r out insg, signaling , pr ov ision in g, an d r esour ce and ser vice d iscover y . OCP is •being dev eloped I ndexby equ ipm en t m anu fact ur er s t o au t om at e end- t o- en d op t ical net w ork Ipr ntov e rnisionin et w or kg. ingMesh Te chnologie Ha ndbook , Four Edit ion being con sid er ed f or im plement at ion as a rest orsat ion capab ilit yth is also rByest or at ion t ech nique for OCP. Cisco Systems, Inc. Man ual pr ocesses ar e used in t oday ' s opt ical n et w or k s t hat r eq uir e t he u se of m u lt ip le Pub lish er: Cisco Press m anagem ent sy st em s t o set up m ult iple segm ent s f or end- t o- en d cir cu it pr ov ision in g. OCP Sep tem 1 1, 2 003 allevPub iatDat ese:t his b y ber allowin g op t ical net w ork s t o be const r uct ed in n ew w ays. For OCP opt ical I SBN: 158 705 -1 19 -2 net w or ks, m or e int elligence in n et wor k element s ( such as band wid t h aw ar eness and ser v icelevel sup Pages: por11 t )28r educes capit al an d op er at ional cost s. NNI is an opt ical sub net w ork in t er f ace for sign alin g an d r ou t in g in a net w ork dom ain. At t his t im e, GMPLS t ech nology is lik ely t o evolv e as t h e pr efer red im plem ent at ion in an OCP O- NNI . This d oes not m ean t hat G. ASON w ill n ot b e par t of NNI . I n fact , G.8 080 m ak es a pr ov ision for NNI and ot h er opt ical int er face signaling and r out ing p rot ocols. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent cu twt ingt ech At t hisial t iman e,dnet or k edg eleme en t s nologies. ar e considering NNI f or signaling and r out in g ex ch ange bet w een t he opt ical net w or k elem ent s ( such as sw it ch es an d rou t er s) t o set up ligh t - pat h r eq uest s t hr ou Con gh tcise he op corse of n ett echn w or kolog . ovt ical er v iew ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . NNI is anot her em er ging indu st ry - st and ard p rot ocol. Wh ile NNI is in d ev elop m en t , UNI ext ensions and pr iet y excov t ensions bepor used eq uipm s. For exam p le, st an dar d New chapt er sopr include erag e w ofillim t antby t opics likeent VoIvPendor and EAP I P r out in g u sin g OSPF pr ot ocols can b e used t o supp ort cir cuit pr ovisioning , and signaling can be accomCov p lished it hcut RSVPw itthechn opt ologies ical, UNIlik , eand oprniet ary kex t ensions. erag ewof t ing TE edge optpr ical et wor ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Next-Generation Protection and Restoration Pr ot ect ion and r est or at ion w ill evolv e t o of fer m or e t h an j ust " pr em ium " and " pr ot ect ed " opt ion s for pr ivat e- line cir cu it s. Most n ew ser vice of fer in gs n ow include class- of - ser v ice cap abilit y. SDH/ SONET APS ring s t y pically h ave t he h ig hest level of p rot ect ion available in opt ical n et w or k s. •Wit h 50 m s for Table of Content APS opt icals n et wor k s, t hey ar e v iew ed as t he k ing s of t he t elecom w orld and ar e •v iew ed as t y pical I ndex by m ost cust om ers. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ot er t yp es of rest By h Cisco Systems, Inc. or at ion can and w ill evolv e t o allow cu st om er s w it h pr ot ect ed ser v ice r est or at ion w it hin sev er al seconds. Mesh or ot her n et w or k in g pr incip les can r eser ve or en gineer ban dw idt h by p rior it y , div ersit y , and lat ency. I n consider at ion of b andw idt h , a backu p r out e Pub lish er: Cisco Press w ould not be r equir ed t o be d ed icat ed or p lan ned f or , t hu s savin g m oney an d allow ing for Pub Dat e: Sep tem ber 1 1, 2 003 opt im izat ion of band w id t h wh ile ser vin g cust om er needs. I SBN: 1- 58 705 -1 19 -2

Unpr otPages: ect in 11 g 28 ser vice pr ot ect ion usin g man ual r est orat ion is anot her ser v ice t h at can be of fer ed t o cu st om er s w ho alr eady in vok e Lay er 3 pr ot ect ion schemes. Serv ice w ould be p rov ided wh en r ep air is comp let e or w hen m an ual r est or at ion is don e. Pr ot ect ion r out es can also be v irt ual ( 1 : n) . Wh en a lig ht pat h is creat ed, a pr ecalculat ed pr ot ect ion p at h is recalcu lat ed , bu t not r eser ved. This t echniqu e allow s con st an t r eopt im izat ion The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of of t he opt ical net w or k. essent ial an d cu t t ing- edg e t ech nologies. Pr eem pt ed ser v ice u sin g p rot ect ion band w id t h pr ovid es ser vice t o ot her cust om er s. Pr eem pt ed ser v ice is cise not ov new o t he d I ies LECessen com m untitoy.n et I f wor t h ekpr ot pr ectofession ed t r aff als ic r eq r ot ect ions, Con er vtiew s ofRBOC t echnan olog t ial ing at uir alles levpels, f rom t he prnov eem pt ed ser v ice on t h e pr ot ect ed r out e is af fect ed ( u nav ailab le) . ice t o ex pert . Mix edNew servchapt ices, er such as I P an d erag TD M, canimalso t olike conVoI ver P t ligh pat h r eq uest s across s include cov e of por tuse ant OCP t opics andt -EAP opt ical n et w or k s. OCP pr om ises t h e abilit y t o conv er ge ser v ice lay er s and app licat ions. Secur it y and prCov iv acy hecut light h can be gologies uar ant eed, allow vice d ent ise pr ovid er s t o eragofe tof t ingpat edge t echn lik e opt icaling n etser wor k inganand ster orpr age m anage resour ces w it h in t h eir d om ain s and allow ext en sion int o ot her dom ains. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Serv ice pr ov id er s n eed m ult iple solut ions f or of fer in g UCP and / or any ot h er t yp e of sig naling pr ocols. n et nologies w or k s ar Hand e pr edom lyt hlegacy net w or bu ild s or nex t -refer gener at ion b uilds. I n tot ern et w orOpt k inical g Tech bookinant , Four Ed it ion , is a kcom pr ehensive ence t hat Legacy op t ical net w ork b uilds w er e built for cir cu it swit ched t r aff ic. Typ ically , next generat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w orkion ing net w or ks are built f ort he b otthercir - swit and ologies, pack et - sw t r affused ic. Sev al ot 'her t ywpes t echnologies. Mast er m cu s, it con cepched t s, t echn anitdched devices in er t oday s net ork of ing opt ur es tem ploy por ot hat ere phy sical ing an d sw ching, but tWAN hey ar e not cover induical st ryar. chit Learect n how o incor int er net wlay orer kinr gout t echn olog iesitin t o a LAN/ env ir onm ent .ed her Come.plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary Op t ical net w ork s p rov ide t h e m ean s t o t ran sp ort aud io, v id eo, and dat a acr oss opt ical t r ansm ission and sw it chin g sy st em s. Man aging and cont r ollin g opt ical net w or k developm ent is w ell und er way by t h e I ETF, OI F, and I TU. Sig naling and swit chin g op t ical net w ork s p rov ide •cost - ef fect ively Table Content intofegr at ed svoice, v id eo, dat a, an d st or age applicat ions. Secu re an d scalable •net w or ks using I ndex opt ical cont r ol p lan es will of fer n ew SLAs f or ser v ice p r ovider s and add it ional Iban nt e rn w or ing Te H aov ndbook dwetidt hkfor enchnologie t er p risespr iders., Four th Edit ion By Cisco Systems, Inc.

Sever al m et hods of im plem en t at ion w ill be used by pr ov iders and cu st omer s alike. Wit h m anuf act ur ers an d ser vice and ent er pr ise pr ovid er s b elong ing t o on e or m or e of t he st and ard s Pub lish er: Cisco Press and w or kin g g rou ps, im plement at ion is d eliber at ely reser v ed. How ever , t her e ar e ong oin g ef for t s e: Sep tem ber 1 1, 2 003 fr omPuballDatt hese org anizat ions in how t hey w ill conv er ge wit h each ot hers' pr oposals. I SBN: 1- 58 705 -1 19 -2

Ev en in Pages: t od ay' 11 28 s opt ical n et w or k s, fiber capacit y is u nder used . As a mediu m, fiber - opt ic cable h as no challen ger for b andw idt h capacit y . Op t ical net w ork ing w it h t he u se of sign alin g an d man aging nex t - gener at ion equ ipm en t an d ex ist in g legacy equip ment allow s ser v ice an d ent er pr ise pr ov iders and cu st omer s t o gar ner t he benefit of op t ical net w ork ing . Obv iously , not ev er y asp ect of opt ical n et w or k ing w as discu ssed in t h is ch apt er . You are en cou rag ed t o r ev iew t he r efer en ce m at erials t o ion v isitoft he s bodallies'inWeb es. The u pdat an ed dedit t hestband est ard - selling one sit net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: •

What ar e t he LSR' s int er faces? Table of Content s

I ndext hr ee plan es ar e u sed in G. 808 0 t o per for m signaling an d conn ect ion What I nt e rn et w or kser ingvTe chnologie s H a ndbook , Four th Edit ion ices? •

2:

By Cisco Systems, Inc.

3:

What is t h e pur pose of d omain s used in G. ASON?

Pub lish er: Cisco Press

4:

When y ou u se PONs, w hich t r af fic, up st r eam or d ow nst r eam , r equir es m ore ban dw idt h? Why ?

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Pages: 11 28 t w o dom ain s ar e used f or adm inist r at ion in t h e OTN for t h e ov er lay m odel? 5 : What

6:

What t y pe of op t ical net w ork allow s cust om ers t o d ir ect ly plug opt ical signals r eg ar dless of op t ical lin e rat e or fr am ing ?

7 : ed I n edit G. ASON, hatb is as tallhe inr eference b etrween dompains? The u pdat ion of wt he estused - selling one net pwoint ork ing ef erence rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. 8 : Which pr ot ocol is used t o p rov ide link an d neig hbor ing nod e k now led ge? Wh y? Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • I TU- T Recom m en dat ion G. 808 0/ Y. 13 04, w w w .it u . in t / r ec/ r ecom m endat ion. asp? t y pe= it em s&lan g= E& par en t = T- REC- G. 80 80- 2 001 11- I •

Table of Content s

•

I ndex

•I nt dr - iet ccam p- gm p lschit ect, uFour r e- 0 ht tion p: / / w w w 1. iet f. or g/ m ail- archiv e/ iet f e rnaft et w or kf-ing Te chnologie s Har a ndbook th4, Edit ann ounce/ Cur r ent / m sg22 930 .h t m l By Cisco Systems, Inc.

• RFC Pub lish 2 026 er: Cisco , w wPress w .iet f .or g/ rf c/ rf c2026 . t xt Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

• RFC 2 748 , w w w .iet f .or g/ rf c/ rf c2748 . t xt Pages: 11 28

• RFC 3 031 , w w w .iet f .or g/ rf c/ rf c3031 . t xt • RFC 3 035 , w w w .iet f .or g/ rf c/ rf c3035 . t xt The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. • RFC 3 036 , w w w .iet f .or g/ rf c/ rf c3036 . t xt Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom ice t oF200 ex pert . , w w w .oif or um .com / • UNInov 1 .0 , OI 1. 125 New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP • NNI 1. 0, w w w .oif or um .com / Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age h oredOI byF2Cisco stwems, w or leader in net w or king f or t he I n t er n et . • NNIAut DDRP, 002 .0Sy 23, w w .oif orldw umide .com / I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat •enables dr aft - iet netf-wmorpkin ls- ggen p rer ofessionals alized - sig naling, t o un derst ht t p:and / / w an w wd1.im ietplem f. or g/ enmt ailcontarchiv em por e/ar ietyf -int er net w ork ing t echnologies. ann ounce/ Cur Mast r ent /er m sg20 t he t 113 er m.h s, t m con l cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, •and drspeed, aft - iet f-tm p lslsp-is h ier chplet y, htet p: f. eorrg/ archiv e/ iet f -ics t hat are essen t ial t o all h is book a ar com an/ /dwuwp-wt1. o-iet d at efm er ailence t o t he t op ann ounce/ Cur r ent / m sg20 272 .h t m l net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e •hardr aftar- iet ls- b und le, wser ww .iet f .or pred oceedings/ 2nov I - D/nology dr af t - iet pls-ion bu ndle04. t x t on dw e, fprmotpocols, and v ices invg/ olv . Fu ndam 0ent al t/ech inff-ormmat is pr ov ided a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t• o dr enaft su-re ceptp-comp ehsonet en sion andhtrtet t ion, and adordit esou r e/ ces ietcon f- ccam gm prls- sdh, p:en //w w w 1. iet f. g/ional m ail- rarchiv ietffor - fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy ann ounce/ Cur r ent / m sg23 580 .h t m l syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr ct-iv it fy ccam an d im iciency, ing t he rht eader mwake , coste/- eff • odu dr aft iet p- pr gmov pe ls-eff sonet - sdh-help ex t ensions, t p: / / w w 1.mor iet f.eoring/t elligent m ail- archiv iet ficient decisions for t h eir net w ork s. ann ounce/ Cur r ent / m sg18 647 .h t m l • dr aft - iet f- ccam p- gm p ls- r out in g, ht t p: / / w w w 1. iet f. or g/ m ail- archiv e/ iet f ann ounce/ Cur r ent / m sg20 086 .h t m l

• dr aft - iet f- m p ls- ldp - st at e, ht t p: / / w w w 1. iet f. or g/ m ail- archiv e/ iet f ann ounce/ Cur r ent / m sg12 101 .h t m l • dr aft - iet f- m p ls- cr ldp, ht t p: / / w w w 1. iet f. or g/ m ail- archiv e/ iet f ann ounce/ Cur r ent / m sg21 677 .h t m l Table s ify , w w w .iet f .or g/ pr oceedings/ 0 1m ar/ I - D / m pls- cr lsp- m odify - 03 . t xt • dr aft - iet f- m p ls-of cr Content lsp - mod •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

• dr aft - iet f- m p ls- g en er alized - cr- ld p, ht t p: / / w w w 1. iet f. or g/ m ail- archiv e/ iet f By Cisco Systems, Inc. ann ounce/ Cur r ent / m sg20 114 .h t m l Pub lish er: Cisco Press

• drPub aftDat - iet m ptem ls-ber cr ldpnnu m, ht t p: / / w w w 1. iet f. or g/ m ail- archiv e/ iet f e:f-Sep 1 1, 2u003 ann ounce/ r ent /m 677 .h t m l I SBN:Cur 1- 58 705 -1 19sg21 -2 Pages: 11 28

• dr aft - iet f- m p ls- ldp , ht t p: / / w w w 1. iet f. or g/ m ail- archiv e/ iet f - annou nce/ Cur r en t / m sg 089 73. ht ml • dr aft - iet f- m p ls- lm p, w w w .iet f .or g/ pr oceedings/ 0 1m ar/ I - D / m pls- lm p- 02. t x t The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. • dr aft - n adeau- ccam p - gm pls- t c- mib , ht t p: / / w w w 1. iet f. or g/ m ail- archiv e/ iet f ann ounce/ Cur r ent / m sg16 480 .h t m l Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . • dr aft - n adeau- ccam p - gm pls- label- m ib, ht t p: / / w w w 1. iet f. or g/ m ail- archiv e/ iet f ann ounce/ Cur r ent sg16 481 t m l e of im por t ant t opics like VoI P and EAP New chapt er s/ m include cov.herag Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age • dr aft - n adeau- ccam p - gm pls- t e- mib , ht t p: / / w w w 1. iet f. or g/ m ail- archiv e/ iet f ann ounce/ Cur r ent m sg16 .h t mwl or ldw ide leader in net w or king f or t he I n t er n et . Aut h ored by /Cisco Sy483 st ems, I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat • dr aft - n adeau- ccam p - gm pls- lsr - m ib, ht t p: / / w w w 1. iet f. or g/ m ail- archiv e/ iet f enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing ann ounce/ Cur r ent / m sg15 246 .h t m l t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 24. VoIP Obj e ct i ve s • •

Table of Content s

Under st and H.3 23 net w or k devices. I ndex

I nt e rn Wor et w orkk w ing Four th Edit ion it hTetchnologie he H. 32 s3 Hparndbook ot ocol, su it e. By Cisco Systems, Inc.

Know t he Session I nit iat ion Prot ocol ( SI P) . Pub lish er: Cisco Press

Descr ibe conn ect ing VoI P n et wor k s w it h t he SS7 net w or k .

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 705ev -1 19 Ch ances are1-t58 hat en-2if y ou are new t o t he net w or k in g in dust r y , y ou h ave h ear d of v oice ov er I nt er net Pages: Pr ot 11ocol 28 ( VoI P) . VoI P is t he t r anspor t of voice t r aff ic ov er an I P in fr ast r uct ur e r at her t han ov er t he t rad it ion al t im e- division mu lt iplex ing ( TDM) - based t elephon e net w ork , also called t he pub lic sw it ched t elephon e net w or k ( PSTN) . VoI P r efer s t o t he t r anspor t of voice at t he net w or k layer of t h e I nt er nat ional Org anizat ion for St andar dizat ion' s ( I SO' s) open syst em s int er con nect ion ( OSI ) m odel.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of VoI P h as been g ain ing mom ent u m in t he ind ust r y over t h e past few y ear s w it h t h e su ppor t of essent ial an d cu t t ing- edg e t ech nologies. indu st ry heavy w eig ht s, such as Cisco. Many ent er pr ise com p anies, com pet it iv e local ex chang e carr ier s ( CLECs) , and incum b en t local exchan ge car rier s ( I LECs) deploy VoI P solut ion s of v ary ing degr ees. Like ov aner ytvhing he m ain dt ial r iv ing orce d ofession VoI P deploym isels, monf rom ey . Con cise iew sinofbusiness, t echn ologt ies essen t o nfet worbehin k ing pr als at ent all slev The dnov ep loym ent of pr ivat e I P infr ast r uct ur es t o t ran sp or t v oice sav es comp anies on leased cir cu it ice t o ex pert . cost s, man agement ov er h ead , and equipm ent r eq uired. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP For exam ple, as show n in Figur e 24 - 1, a t y pical ser v ice p rov ider net w or k cont ains sw it ches, int er m acherag in e et r unk s (tIing MTs) t hatt echn are ologies high- speed lin ks bet w een it ches, Sy st em 7 Cov of cut edge lik e opt ical n et wor ksw ing and stSignaling or age ( SS7) equipm ent , su ch as sign alin g t r an sf er point s ( STPs) , and a st aff t o r un t he in fr ast r uct ur e ( not show Aut h n ored in t h bye Cisco fig ur e)Sy . These st ems,are w orver ldwy ide high leader cost s,inpar nett w icuorlarly king f for or CLECs, t he I n t er w hich n et . m ig ht not hav e t h is cap it al up f ron t . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ryFigu . Learrne how t o .incor at e int net w orr kin olog WAN env 2 4 -1 Serpor v ice Prer ov ide a ng dt echn Ba si c ies VoIinPt o IanLAN/ fr a st r u ct uirr onm es ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. [ View full size im age]

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

NO TE

Figur e 24ov - 1erisv iew notsmofeant t o olog show yt ht ial ing t o in naetnet k, pr becau se t hat t akels, e f rom Con cise t echn iesever essen worwkor ing ofession als wou at allldlev qu it e a lar ge f igur e. I nst ead, it is meant t o sh ow how each net w or k can b e deploy ed in nov ice t o ex pert . it s m ost b asic w ay . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age VoI P equ ip ment , such as I P ph ones, voice- en abled gat ew ay s, and call m anager s, can b e pu rchased and by instCisco alled Sy in st exems, ist in gw Ior Pldw netide w orleader ks f or ainsm all f r act ionf or of t the he I TDM Aut h ored net w or king n t er nnet et . w ork . For indiv iduals or com p anies t hat need t o off er voice t r anspor t and ser v ices, but t h at do not hav e t he I n t ern capit aletf w ororlar k in geg exp Techen nologies dit ur es,Hand VoI Pbook m ight , Four be at hgood Ed it ion alt ern , is at a ive comfor pr ehensive incr easingrefer v oice ence sert vices. hat enables The p r imnet ar ywror eason kin g pf or r ofessionals VoI P is t het osav uning derst s on and perancall d imt plem oll access. en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing VoI in t ertnoalincor v oice anspor aswaorPrkin iv at Br anch ( PBX)WAN r ep lacem en t in induPstisryu. sed Learfor n how port rat e int ert ,net g teechn ologExchan ies in t oge a LAN/ env ir onm entt he . off ice, an d as a long haul voice t r anspor t in ent er pr ise or ser v ice pr ovid er n et wor k s. Som e Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, specu lat e t hat P wis ill asoon legacy w or kt,oand migh somare eday . How and speed, t h isVoI book com replace plet e antdheu pt o- d atTD eM r efneretence t he itt op ics t hat essen t ialevter, o all w it h t he am oun t of legacy TDM equipm ent deploy ed t h rou ghou t t h e w orld , VoI P w ill likely net w or kin g p rof essionals, r egar dless of ex pert ise. com plem ent t he TD M n et w or k f or m any y ears t o com e r at her t han r eplace it . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Anot h er notpred area ofand costser sav ingsinv has wndam it h t h ent e I Palinf rastnology r uct ur e. t icular forov ided on har dw ar e, ot ocols, v ices olvt oeddo . Fu t ech inf Par or mat ion ly is pr com panies t hat ead inf rast r uct ur einin place, longh aul v oice sers, v ices can quest b e add ed a b r oad r ang e ofalr int egryalhav sy est an em IsPand serv ices, clud ing det ailed descr ipt ion rev iew ions m expcept en sivcomp ely t han creat e TD M- based n et wor k f or v oice ser t o uch en suless re con r eh en sioning anda rsepar et en tat ion, and ad dit ional r esou r ces f or fu rtvices. her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy The f easib ilitovid y d ep one t rhe cu rricent orkt he t r affic and uchenvoice t r aff ics needs to syst em s, pr in genads m or ealist pictnet ur ew of real-load w or ld n ethwow or kming vir onm ent in w hich beofsu ppor t ed. oper For at exe. amp le, ifand a corp ion fhas offim ices in New York and New Jerwsey, VoIease P can b e pr essionals Tools gu idorat elines or opt izing syst em per for m ance ill incr used o iv t ritanspor t he inteereff siticiency, e v oice thelp r af fic herr eader t h an mak ingmor t hee com pan y pay f or- eff t ollicient access pr odutct y an d tim pr ov ingr at t he m ake in t elligent , cost on a p er - call The ab ilit decisions for tbasis. h eir net w ork s. y t o pr ov ide t h is t yp e of ser v ice also d ep en ds on t h e available ban dw idt h and t he abilit y t o p rov ide t he pr oper q ualit y of ser v ice ( QoS) . Anot h er cost sav ing s can b e seen not wit h t h e eq uipm ent it self, but w it h t he st aff t hat is n eeded t o ru n it . Alt houg h st af fing t y pically inclu des indiv iduals w h o un der st an d w id e- ar ea n et w or k ( WAN) con nect ion s, t her e is a n at ur al ov er lap w it h t he sam e indiv iduals w ho m aint ain t he r out er s, becau se VoI P is based on I P t r an sp ort . The lear ning cur ve is of t en a lot less for som eone

t o com e u p t o speed on VoI P an d associat ed config ur at ion st eps t han for som eone w ho m ust learn t h e en t ire ser vice pr ov ider net w or k and t echnologies such as SS7.

NO TE • •

of Content s SS7 is aTable p rot ocol su it e t hat ser v ice p rov ider s use for call sign alin g, cir cu it m aint enan ce, I ndex and billing of ser v ices f or w or ld w id e v oice serv ices.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

ThisPub ovlish erlap is not obser ved in all cor por at ions. Many com panies sep arat e pur e I P an d voice job er: Cisco Press r oles. Th is is ment ion ed t o ident ify ot her w ay s in w h ich smaller com panies can sav e m oney. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

H.323 Network Devices To m ost people, VoI P m ean s alm ost exclusive use of a suit e of p rot ocols f rom t he I nt er nat ion al Telecom m unicat ion Union ( I TU) un der t he um br ella of H. 3 23, b ut pr ot ocols su ch as Session I nit iat ion Prot ocol ( SI P) w hen used w it h Session D escr ip t ion Prot ocol ( SD P) , can pr ovid e t he •sam e t yp e ofTable Content s VoI Pofcall m anagem ent fun ct ion alit y . SI P is discu ssed lat er in t his ch apt er. •

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IBefor nt e rn e et w ing Te chnologie s Har a ndbook Four tht h Edit wor e kdiscuss t he pr im y pr ot,ocols at ion m ak e up t he H. 3 23 pr ot ocol suit e, it is im por t an t tBy hat y ou under st and t he d ev ices in t h e H. 323 net w or k and w hat fu nct ions each p er f orm s. Figur e Cisco Systems, Inc. 24 - 2 sh ows som e of t h e m ore com m on H.3 23 dev ices. Their appr ox im at e locat ion in t he H. 32 3 net w or k is indicat ed. Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 Figu r e282 4 -2 . H .3 2 3 N et w or k De vi ces a n d Appr ox im at e Ne t w or k Loca t i on

[ View full size im age]

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

H.323 Terminals

An H.3 23 t erm inal is ident ified in t h e H. 323 specif icat ion as a dev ice t h at p rov ides r eal- t im e, t w o- w ay com mu nicat ion w it h anot h er H.3 23 t erm inal, gat ew ay, or m ult ipoint con t r ol un it ( MCU) . For H. 32 3 t er m inals, supp ort for voice is r equir ed, and v ideo an d d at a ar e op t ion al. An H. 323 t er m in al is m or e easily descr ibed as a device t hat dir ect ly sup por t s and u nder st ands H. 323 and d oes n ot n eed a g at ew ay for t r anslat ion. This is similar t o t erm inal eq uipm ent t yp e 1 ( TE1 ) d ev ices in an I SDN n et w or k . Ex am ples of H.3 23 dev ices ar e I P Phon es, v oice- enab led r out er s, and voice- en abled access ser ver s. The r out er an d access ser ver ar e includ ed in Figur e 24 - 2 b ecau seTable t heyofare discu ssed in m or e det ail lat er w hen dial peer s ar e discu ssed. • Content s •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

H.323 Gatekeepers By Cisco Systems, Inc.

H. 323 gater:ekCisco eep er s ar e d ev ices t h at allow t he H. 323 net w or k t o be scaled. Dur ing nor m al H. 32 3 Pub lish Press conf ig ur at ion on a voice- en abled r ou t er or access ser v er , d ial peers are u sed t o id en t ify t h e Pub Dat e: Sep tem ber 1 1, 2 003 dest inat ions f or n um bers or gr oup s of num ber s t h at ar e t o be analy zed and passed t hr oug h said I SBN: 1- 58 705 -1 19 -2 dev ices. A d ial peer is r eq uired for each dest inat ion in t h e H. 323 net w or k t hat calls mu st be 11 28 r out edPages: t o. I n a sm all imp lem ent at ion, con figu r in g d ial peers is not an issue, bu t as t h e net w or k gr ow s, config ur ing dial peer s becomes m or e of an adm inist rat iv e b ur den. For inst ance, if y ou hav e 45 v oice- enab led r out er s and y ou n eed a m inim um of 1 980 d ial peer s f or a fully m esh ed net w or k ( 44 per d ev ice) , t his does n ot includ e any ad dit ional d ial peer s r equ ir ed for m ult ip le gr oup s for t he sam e dest inat ion. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Iessent nst ead t o config e tnologies. hat m any dial peer s, gat ek eep er s can be u sed t o m anag e t his ialofanh davin cu tgt ingedg e ur t ech fu nct ion. Gat ek eep er s ar e r esponsible f or m anaging H. 32 3 zon es. H. 32 3 zones ar e gr oups of H. 323 dev ices w it hin a log ical con t r ol dom ain. Th is con cep t is sim ilar t o an I P net w or k subn et . Con er v iew t echn essen,t ial k ing m pray ofession levr els, f rom An H.3 23 cise zoneovcan havseof only on olog e gaties ek eeper bu t og n atet ekwor eepers ser ve als as tat heall cont ol d ev ice ice zones. t o ex pert . e of t he ot her m anagem en t f unct ions inclu de secu rit y , call ad mission , for m nov ult iple Som ban dw idt h cont r ol, r esour ce r epor t ing, an d alias an d num ber t r anslat ion or r esolut ion . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP As H. 32 3 d ev ices, such as v oice- enabled rou t ers, ar e ad ded t o t he net w ork , t h ey regist er w it h Cov erag e of cut t ting ologies e opt ical n, et worSt k ing st orpr age t he gat ekeeper using he edge H.2 25t echn Regist rat ion lik , Adm ission and at usand ( RAS) ot ocol. H. 2 25 RAS oper at ion is discussed in det ail in t he sect ion " H. 225 RAS. " Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The H. 2 25 RAS p rot ocol allow s t h e H. 323 dev ices t o ident ify t o t h e gat ek eeper w hich gr oup of Iph n tone ern etnu wm orbers k in g tTech Hand book Fourgt hatEd it ion , is a comt his pr ehensive referically ence, tand hat w hen hey nologies ar e respon sible f or ., The ekeeper builds t ab le dy nam enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing calls are placed t hr oug h H. 3 23 devices, t hey qu er y t h e gat ek eeper f or t he call's dest in at ion tH. echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing 323 dev ice. Th e gat ek eeper eit her f in ds t h e nu mb er locally or q ueries a n eig hbor gat ekeeper indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm for t he d est inat ion H. 323 d ev ice and t hen ret u rn s t hat inf orm at ion t o t he or iginat ion H. 323 ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, dev ice. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

H.323 Reader s Directory w ill obt ain a gGatekeepers reat er un der st an ding

of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a r oad interegr sy st em s and servtices, in cludy ing ailed ionH. s, 32 rev3 iew quest Dirb ect or yr ang g ateekof eep s (al D GKs) ar e dev ices h at allow ou tdet o f ur t herdescr scaleiptt he net w ork ions tinf o rast en sur uct re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ur e. Th e DGK is responsible f or k eepin g t r ack of t h e locat ion of all t h e H.3 23 Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy gat ek eeper s. To com m unicat e w it h each ot her , g at ek eep er s n eed t o k now w here all t he ot h er syst em s, prsovid g awmitor r ealist ur3e23 of devices, t he real- w n et w or fkor ingt he ennvir in w hich gat ek eeper ar e.in As h e dial peerics pict on H. it or is ld possible etonm w or kent t os become pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease lar ge enoug h t hat id en t ify ing t he locat ion of all t he g at ekeepers can becom e an adm inist rat iv e pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient bu rd en . decisions for t h eir net w ork s. The D GK is conf igur ed w it h a list of gat ek eeper s. As calls com e t h rou gh t he g at ek eepers, t h ey in t ur n qu er y t h e DGK for t he locat ion of t h e r em ot e g at ekeeper t hat is r espon sib le for a call t hat is not locally serv ed.

H.323 Gateways By pu r e definit ion, a g at ew ay is a dev ice t h at conn ect s t wo dissim ilar net w or ks. For in st an ce, it m ight t r anslat e bet w een an I P net w or k and an I PX net w or k . I n t he cont ex t of H. 323 , a gat ew ay is a device t hat connect s an H. 323 net w or k t o a non - H.3 23 net w or k, su ch as t h e PSTN. A gr ow ing int er est over t h e past f ew y ear s in t he VoI P w orld has been t he abilit y t o in t er connect t he ser vice pr ov ider SS7 net w ork w it h p riv at e H. 32 3 n et w or k s. •

Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Multipoint Control Unit (MCU) By Cisco Systems, Inc.

The p ur pose of t he MCU is t o pr ov id e t he abilit y t o conf er ence t h ree or m or e H. 323 d ev ices. Ciscoerencing Press Mu ltPub ip lish oiner: t conf has t w o basic m odes of oper at ion—cent r alized and decent r alized. I n Pub Dat e: Sep tem ber 1 1,confer 2 003 en cin g, all H. 32 3 devices com m un icat e d irect ly w it h t he MCU in a cen t r alized m ult ipoint SBN: 1- 58fashion 705 -1 19 -2 point - tIopoint , and t he MCU d ir ect ly man ages t he con fer en ce. Pages: 11 28

I n decent r alized m ult ip oin t conf erencing , each H. 323 dev ice uses m u lt icast t o sen d all inf orm at ion t o t he ot h er con ference p art icipan t s and by passes a MCU. Typ ically, MCUs ar e used only in cen t r alized m ult ipoint con fer en ces, bu t t h ey can be used in a h yb rid fash ion bet w een t h e t w o m et hod s. MCUs can act as a br id ge b et w een cent r alized an d d ecent r alized dev ices, t her eby allow in g a hy br id con fer en ce t o t ak e place. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

H.323 Protocol Suite Alt hou gh t he m ost com m on use of H.3 23 is for VoI P t r anspor t , t h e specif icat ion does include t he capabilit y t o t r anspor t v ideo an d d at a. Th e init ial design for H. 32 3 was t o b e a m ult im edia t r anspor t , n ot j ust v oice. Table 2 4- 1 d escr ibes som e of t h e dif fer en t pr ot ocol st an dar ds t h at ar e •included und Table Content er t heof H. 32 3 us m br ella and t heir int ended use. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Tab le 2 4 - 1 . Spe ci fi ca t ion s Und er t he H .3 2 3 Um br e lla

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

Sp ecifI SBN: ica t1ion Sp 58 705 -1 19ecif -2 ica t ion Su bhe ad ing N a m e Pages: 11 28 Main syst em s oper at ion

I nt e nd ed U se

H. 323

H. 323 is t h e over all oper at ions specificat ion set f or t h by t he I TU. H.3 23 specif ies t h e int er act ion s bet w een t he var ious pr ot ocols used in t h e H.3 23 pr ot ocol suit e. Ther e ar e sev eral v er sions of t h e st andar d. Ver sion 4 f rom 11/ 2 000 is t h e m ost The u pdat ed edit ion of t he b est - selling cur r allen t inspecif one icat netion w ork b eing ing r ef u sed. erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Sy st em cont rol H. 225 H. 225 is u sed for call m anag em ent fu nct ions, such as call set up and t eard ow n. H. 225 is b ased on t he Q. 9 31 icat ion Con cise ov er v iew s of t echn ologspecif ies essen t ialf or t o InSDN. et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . H. 225 RAS H. 225 RAS m essages ar e used f or com mu nicat ion b et ween 323 aytsopics and H. 32VoI 3 gP atand ek eep er s. Th ese m essages New chapt er s include cov erag eH.of im gat por ew t ant like EAP include t he abilit y t o imp lem ent scalabilit y , secur it y , billing, ban dw h cont Cov erag e of cut t ing edge t echnand ologies lik idt e opt ical rnol. et wor k ing and st or age H. 245 H. 245 specif ies t he u se of a cont r ol chann el t o p rov ide Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . r eliable in - band t r anspor t for capab ilit y ex chang e. H.2 45 allow,sFour t he or in g and t er m ing p art ies ence t o agrt hat ee on I n t ern et w or k in g Tech nologies Hand book t h iginat Ed it ion , is a com prinat ehensive refer fu nct ions, such as comp ression / decomp ression ( CODEC) enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing et thods. t echnologies. Mast er t he t er m s, conm cep s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin echn olog ies in tyofor a LAN/ WAN env ir onm ent . Video H. 261 H. 261 specif iesg tthe m et hodolog t he coding and Com plet ew it hs new an d u pdat ed chapt er s on of secur it y ,signals. st or age,This optin ical net or krinatg, specif icat ion decoding v id eo clud esw bit e, scalabilit sour ce y, and speed, t h is book is a com plet e coding an d u p-algor t o- d at e r ef er ence t o frt he t op ics, tand hat er areroressen t o all it hm , sam pling equency handt ial lin g. net w or kin g p rof essionals, r egar dless of ex pert ise. H. 263 H. 263 ident if ies t he com pr ession of v ideo st r eams at low er Reader s w ill obt ain a g reat er un der bit st anr at ding es. of I t LAN is based and on WAN t hen et H.2 w or 61k ing, specif p ar icat t icu ion. lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on io r ang e of int G.egr 71 1, These arices, e notinall ofing t hedet availed ailable CODECS, hey quest ar e ions aAud b r oad al sy st em s and serv clud descr ipt ion s,but revtiew specif icat ion s G. 72 3. 1, G.7 29 som e of t he m or e comm on ones in use. They allow t he . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy com pr ession of v oice t o v ar yin g d eg rees ov er an I P net Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy w ork . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

NO TE The H. 2 61 and H.2 63 v id eo specif icat ion s are out of t he scope of t his ch apt er and ar e not discussed fu rt h er .

H.323 H. 323 describ es t he ov er all H. 32 3 n et wor k an d h ow t h e diff erent pr ot ocols un der t he H. 32 3 um br ella int er act w it h each ot her . This specificat ion is im p ort an t b ecause w it hou t it , t here wou ld be j ust in div id ual p rot ocol sp ecificat ions w it h out any cohesiv e r elat ion sh ip b et w een t hem. •

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I ndex H. 323 also ident if ies wh ich specif icat ion s ar e t o b e used f or v ideo and d at a com mu nicat ions, I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion w hich par amet er s ar e r eq uired, and w hich ar e op t ional. By Cisco Systems, Inc.

H. 323 calls ar e set up in sect ions k now n as call leg s. A call leg is a logical connect ion b et w een t w oPub H.lish 3 23 er m inals. er: tCisco Press Each endpoin t along t h e call set u p p at h has t w o id en t ifiable call legs—in and out . Figur e 24 - 3 illust r at es t he call legs b et ween t w o gat ew ay s in a call. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 2 4 -3 . H .3 2 3 Cal l Le gs

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age The r u le of t hum b is t hat t her e ar e t w o call legs f or each end point t hat perf or ms call pr ocessin g h ored Cisco ems, w ort ldw ide leader or king or t he n t erpr n et . in t heAut call pat h.by The im pSy ortst an t p oint o r emem ber isint hnet at w only end fpoint s tIhat ocess call m essages hav e call legs. I n ot her w or ds, t he r ou t er s t h at ar e u sed t o t ran sp ort I P p ack et s I n t ern et wtor nologies book , Four , ist a com prels ehensive refer hatew ay bet w een h ek in t wgo Tech g at ew ay s do Hand not hav e call legt hs. Ed Soit aioncall hat t rav fr om on e H.ence 323 tgat g er p rsofessionals o un plem en tleg cont tenables hr ou gh net fiv ewIor P kin r out t o an ot her t H. 32 derst 3 g atand ew ayanhdasimfou r call s. em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, H.225 and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. H. 225 is t h e pr ot ocol r esp onsib le for call set up and t ear dow n bet w een H. 323 endp oin t s ( see Reader s w- ill er on un der st an ofk LAN WAN w or k ing, p arand t icu lar ly t ht oe Figur e 24 4) .obt H.ain 22 5aisg reat based Q. 93 1. ding I t wor s in tand andem w itnhetH. 245 , RTP, RTCP har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov com plet e t he call set up and cut t hr ough t h e voice st r eam . I t is im por t ant t o n ot e t hat t heided H. 2 on 25 a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions chann el is open befor e any ot her ch annels used for call set up and is com plet ely separ at e fr om tH. o 225 en suRAS re con cept comp r eh en sion en0t ion, andialadcall dit ional ces use f or fu her ic st udy and H. 245 . H. 225 usesand por tr et 172 f or init set upr esou and rcan dyrtnam por t.s Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy t her eaft er . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net Figu w ork s.r e 2 4 -4 . H .2 2 5 Cal l Se t u p M e ssa ges

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

The b lank lined sect ions in Figur e 24 - 4 r epr esent t he H.2 45 cap abilit y exchan ge pr ocess and t he I SBN: 1- 58 705 -1 19 -2 RTP/ RTCP st r eam creat ion pr ocess f or v oice t ran sp ort . Bot h of t hese pr ocedu r es t ake p lace af t er Pages: 28 call set u p messag es. Th ey are discussed in t he sect ions " H. 245 " and " RTP and t he in it ial H.11225 RTCP. " As show n in Figur e 24 - 4, H. 22 5 u ses sever al m essages f or basic call set up bet w een H. 323 endp oin t s: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Set up Call Pr oceed g s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Con cise ov erin v iew nov ice t o ex pert . Aler t in g New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Con nect Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Setup I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat The f ir st m essage sent dur ing t he H. 2 25 call set up p rocess is t he Set up m essage. Th is m essage enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing is a for w ard m essage, or a m essage t hat t rav els fr om t h e call' s or iginat or ( t he callin g par t y) t o t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t he t er m inat ing p art y ( t he called par t y ) . Th e Set up m essage cont ains in for m at ion sim ilar t o t hat indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . of a Q.9 31 Set up m essage, bu t sever al k ey areas ar e w or t h point ing ou t . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is bookin is plet e anen d tus po- d fat e r ef ence he t op are 25 essen ial t o all Sever al m and at ory foramcom at ion elem ( ItEs) r om Q.er931 arteo rtequir edics in tthat he H.2 Settup net w or kin g p rof essionals, r egar dless of ex pert ise. m essage—pr ot ocol d iscr im inat or, call r efer ence, messag e t y pe, bear er cap abilit y, and user - u ser I E. All ot her I Es ar e opt ion al or f orb idden for u se. Table 2 4- 2 d escr ibes som e of t h e m ost Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e im por t ant con t ent s w it hin t he user - u ser I E. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst emle s, pr a rmt or ealist ic e of real- w-or ld n et w ent w hich Tab 2 ovid 4 - 2in . gPa i ale rCont e npict t surof t ht he e User User I Eor fkring omenavirnonm H.2 2 s5 inSet up pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease M e ssag e pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Su bhe ad ing

D e scri pt i on

pr ot ocolI dent ifier

I dent if ies t h e v er sion of H. 22 5 t hat is su ppor t ed wit h t h is call.

sour ceAdd r ess

The list ed alias of t h e call' s or iginat ion endp oin t .

sour ceI nf o

I dent if ies t h e t y pe of endp oint t hat origin at es t he call.

dest inat ionAd dr ess

The d est inat ion ad dr ess of t h is call set up r equest .

Table of Content s

• conf er enceI D I ndex

A u niqu e ident ifier f or t his conf er ence. All conf er ences are assigned a

I nt e rn et w or k ing Te chnologie s un H a iq ndbook , Four th Edit ion ue I D. By Cisco Systems, Inc.

conf er enceGoal

I dent if ies w het h er t he pu rp ose of t his conf er ence is t o cr eat e, join, inv it e, ex chang e capabilit y , or app ly supplem en t ar y ser v ices.

Pub lish er: Cisco Press

cryPub pt oTokens Dat e: Sep tem ber 1 1, I SBN: 1- 58 705 -1 19 -2

Can be used f or a sim ple aut h en t icat ion m et hod bet w een gat ew ay s or bet w een a gat ew ay and a g at ekeeper. This t ok en is r ecalculat ed at each leg of t he call set u p.

2 003

Pages: 11 28

fast St ar t

Used only if t he fast conn ect pr ocedu r e is t o b e used b et w een endp oin t s.

neededFeat u r es

A list of f eat ur es t hat need t o be includ ed f or t he call t o comp let e.

desiredFeat es ion of t heAblist op t ional f eatone ur es t hat can clu dedpfrov or tides h e call. Thage ese of The u pdat ed ur edit est -ofselling all- innet w ork ingbe r efinerence cover u res ar e not r equir ed f or call comp let ion. essent ial an d cu t t ing- edg efeat t ech nologies. supp ort ed Feat ur es

A list of f eat ur es t hat are su ppor t ed by t h e call' s or ig inat or .

Con cise ov er v iew sy ofAt echn ies t o bneetused wor k ting pr ofession als 45 at all lev els, h2 45Secur it yCapabilit set ofolog f eat ur essen es t hatt ial can o secur e t h e H.2 chann el f rom nov ice t o ex pert . bet w een t h e en dpoin t s. New ifchapt erag of im porf or t ant t opics P and EAP callI dent ier er s includeA cov u niqu ee ident ifier t his call tlike h at VoI is assigned by t h e call' s or ig inat or . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern NO et wTE or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing The sou rceAddr in atcep ionAdd ress ologies, por t ionsan ofdt he user - used user Iin E in essence e ing t echnologies. Mast eress t heand t er mdest s, con t s, t echn devices t oday ' s net ar w ork t he call' s orig in at ing and dest inat ion nodes. How ever , t he sou rce ad dr ess n um ber indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . ( E. 1e64 ber an ) also is ined clu chapt ded inertsheoncalling y or n um beropt I E, asnet in w Q.or9 k31 Setscalabilit up Com plet w itnum h new d u pdat secur itpar y , tst age, ical in g, y, m essages. Fur t her mor e, t h e dest in at ion ad dr ess is in clu ded in t he called p ar t y num er t o all and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he op ics t hat are essen b t ial I E.kin Thgepdest inat ionAdd ress dless is a requ ired net w or rof essionals, r egar of ex pertfield ise. f or H. 323 d ev ices com pliant w it h v er sion 2 or lat er. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions You becept aw arcomp e t h at ersion e ar eand f our en t and v ersions of H. 32 3, an d t hey diff ow .t h e t o enshould su re con r eht hen r etdif enfer t ion, ad dit ional r esou r ces f or fu rt er herinsthudy rCov elaterag ion sh et w ext eenend p rot is h andled. por t ant s, cebut is t he art As e ip is b also edocols n ot only t o new Of n etnot worable k ingim concep alsof ast t o St old er field. , legacy m enem t ioned Table fast St t field w or k srealin conj t heenf ast connect syst s, prin ovid in g a2 4m 2, or et hreealist ic ar pict ur e of t he w orun ldctnion et ww oritkhing vir onm ent s in w hich oced ur e, fir st av at ailable in ver 2.elines Fast con ov ides t he ilitfor y tm o ance open wailllog icalease chan nel pr of essionals oper e. Tools andsion gu id f or nect opt imprizing syst emab per incr forodu capctabilit exchan eb y cut thelp ing dow onr eader t he num ber mor of r oun t rips requ ired call pr iv it y yan d im prge, ov et her eff iciency, ing tnhe m ake e indt elligent , cost - efffor icient set up. decisions for t h eir net w ork s. I n ot her w or ds, v er sion 1 specif ies a t ot al of sev en or eigh t r oun d t rips bet w een H. 323 dev ices r eq uir ed f or call set u p. Ver sion 2' s fast connect pr ocedur e allow s call set u p t o t ak e place ov er t w o r ou nd t r ip s bet w een H. 323 d ev ices. The fast conn ect pr oced ur e w as creat ed t o d ecr ease t h e am ount of t im e t hat call set u p t akes.

Call Proceeding The Call Pr oceeding m essage is sent in t he back w ard d ir ect ion —fr om called p art y t o calling par t y . The Call Pr oceeding m essage sp ecifies t h at t h e call set up p rocess has begu n. Th is can b e seen as t h e ack now ledgm ent t hat t he Set u p m essag e w as r eceived by t h e called par t y and is being act ed on . Lik e t he Set u p m essag e, sev er al f ield s ar e requ ired—pr ot ocol discr im inat or , call •r ef erence, m Table of Content s essage t yp e, and user - u ser I E. •

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INot nt e ice rn et twhe or kab ingsence Te chnologie of t h es bear H a ndbook er cap , Four abilit th y Edit field. ion This f ield is not pr esen t because t h e calling par t y t y pically is r espon sib le for st at ing t h e bear er cap abilit y in t h e init ial Set up m essage. For By Cisco Systems, Inc. Call Pr oceed in g, Aler t ing, an d Conn ect messag es, t he bear er cap abilit y I E is op t ional. Table 2 4- 3 descr ibes som e of t he n ot able f ields t hat are in clu ded in t he user - u ser I E of t he Call Proceeding Pub lish er: Cisco Press m essage. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Tab le 2 4 - 3 . Pa r t i al Cont e n t s of t h e User - User I E f r om a n H.2 2 5 Cal l Pr oce edi ng M e ssage The u pdat b est selling all- in- one net w ork ing r ef erence p rov ides cover age of Su bhe aded ingedit ion ofDtehe scri pt -i on essent ial an d cu t t ing- edg e t ech nologies. pr ot ocolI dent ifier I dent if ies t h e v er sion of H. 22 5 t hat is in use. dest inat o er v iewAllow t he olog called art y ttoialident w het herpraofession gat ew ay included w it hin ConionI cisenf ov s of t sechn ies pessen t o nifetywor k ing alsis at all lev els, f rom nov ice t o ex pert .t he call p at h. callI dent if ier A u niqu e ident ifier f or t his call t h at is assigned by t h e call' s or ig inat or . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP h2 45Ad dr ess A specific t r anspor t addr ess on w hich t h e called en dpoint or g at ek eep er Cov erag e of cut t ing ologies ical n etH. wor and hanedge dling ttechn he call w ant slikt eo opt est ablish 24k5ing sign alinst g.or age Aut h ored by Cisco st ems,itw or ldw ide leader w orPr king f or t he Aler I n t er n et, .and Con nect h2 45Secur it yMode h2Sy 45Secur yMode is list ed in in t henet Call oceeding, t ing m essages if secur it y is r equest ed in t he in it ial Set up m essage f or t he I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat H. 245 chan nel. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing fast Connect Refu sed A called ret u t hisologies, f ield t o an t hed callin g par t y ifinfast con' snect t echnologies. Mast er t he t er m s,p art cony cep t s,rntsechn devices used t oday net w ork ing pr oced ur es ar e not su ppor t ed. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, feat u reSet A list ing of t he su ppor t ed feat ur es for t his call. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. When Prain oceeding isan retding ur ned t o t he callin g par y,orsev er alp field s lar serly v et has Readert shew Call ill obt a g reatm eressage un der st of LAN and WAN n ett w k ing, ar t icu e answ t o pr t hot e ocols, callingand par tser y rvequ s olv in ted he. call Set up . First , n nology ot ice t hat t he callI enpr t ifier is on har dwers ar e, icesest inv Fu ndam ent al t ech inf or mat iond is ov ided list . This f ield imp bot h par t iesincan t r ack w hich ar equest for wions h ich a b ed r oad r ang e ofisint egror alt ant sy stso emt shat and serv ices, cludkeep ing det ailedofdescr iptmessages ion s, rev iew call a called y receiv es ar et set m essage itional h t he rh245 it y fu Capab set., it t o enI Ds. su reWhen con cept comppar r ehten sion and enup t ion, and adw dit esou rSecur ces f or rt herilit styudy rCov espon dse bisy also set t in g end t he ed appnrop riat et h24 5Secu y Mode in t h e tCall Pr oceedin in g, an d erag ext ot only o new n et rit wor k ing concep s, but also t o g, oldAlert er , legacy Con t heic fast Refrealusedwfor ield. called t y onm u sesent t his field to syst nect em s, mpressages. ovid in g aAlso m ornot e rice ealist pictCon ur e nect of t he ld nThe et w or k ing par en vir s in w hich not y t he calling t y Tools t h at t and h e fast nect f or pr ocedur e is not ort ed f rom eitwhill er incr v endor pr ofifessionals operpar at e. gu idcon elines opt im izing systsupp em per for m ance ease im plem iond or erov sion supp ort . help ing t he r eader m ake mor e in t elligent , cost - eff icient pr odu ctent iv it at y an imvpr e eff iciency, decisions for t h eir net w ork s. The h 245 Addr ess field is u sed in t he Call Proceed ing and Aler t ing m essages. This f ield ident if ies t he addr ess t hat is requ est ed for u se for t he H. 245 signaling chan nel. The Set up m essage can use t h is field, bu t on ly if t he callin g p ar t y suppor t s H. 2 45 sig naling befor e t h e con nect st at em en t . I t 's mor e com m on f or t h e Call Pr oceedin g an d Aler t ing m essages t o u se t his f ield t han it is for Set up t o u se it .

Alerting The Aler t ing m essage is also sent in t h e back war d dir ect ion t o not ify t he callin g par t y t hat t he pr oper end point has b een ident ified and is r in ging . As w it h t he Call Proceed ing m essage, some fields ar e r equir ed—pr ot ocol d iscr iminat or, call refer ence, messag e t y pe, and user - user I E. Wit hin t he user - u ser I E, t here are f ield s t o n ot e f or t he Aler t ing message. Table 2 4- 4 d escr ibes •sev er al of t heTable s s t hat ar e used in t he Aler t ing m essages. comofmContent on field •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Tab le 2 4 - 4 . Pa r t i al Cont e n t s of t h e User - User I E f r om a n H.2 2 5 Ale r t in g Pub lish er: Cisco Press M e ssag e Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Su bhe ad ing Pages: 11 28

D e scri pt i on

pr ot ocolI dent ifier

I dent if ies t h e v er sion of H. 22 5 t hat is in use.

dest inat ionI nf o

Allow s t he called p art y t o ident if y w het her a gat ew ay is included in t h e call pat h .

The pdatifed b est - selling one nett hwat orkising r ef erence idess cover age callIudent ieredit ion of A ut he niqu e ident ifier allf orint his call assigned by tphrov e call' or ig inat orof . essent ial an d cu t t ing- edg e t ech nologies. h2 45Ad dr ess A specific t r anspor t addr ess on w hich t h e called en dpoint or g at ek eep er han dling t he call w ant s t o est ablish H. 24 5 sign alin g. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom h2 45Secur nov iceitt yMode o ex perth2 . 45Secur it yMode is list ed in t he call Pr oceedin g, Alert in g, an d Connect m essages if secur it y is r equest ed in t he in it ial Set up m essage f or t he H. 2 45 New chapt er s include chann el. cov erag e of im por t ant t opics like VoI P and EAP alertCov in gAddr dentedge if ies tthechn e addr ess oflikteheopt p art forstt or h isage call. eragess e of cut It ing ologies icaly nbeing et woraler k ingt ed and scr eeningI nd icat or I dent if ies w het h er t he alert ed dev ice's addr ess is visible in t his m essage. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . capacit y List s t h e called par t y 's cur r ent call capacit y . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing The as cerpor t ain s tnet hatwshould notolog ed. ies Th einaler Addr essenv andir onm t he ent . indu Aler st ry .t ing Learmnessage how t ohincor at efield int er or kin g tbe echn t o at ing LAN/ WAN scr eeningI nd icat or w ork t oget her in t he ev en t t h at t h e called par t y is t o be screened fr om t he Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, callin g p art y. By scr een in g ad dr esses, a level of secu r it y can be in st it ut ed dur ing t he call set and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial up t o all pr netocess. w or kin g p rof essionals, r egar dless of ex pert ise. The capsacit f ield cu rr call stcap acit y of of LAN t he called par tny et . Iwt 'or s imp ortpant forlar oblyvious Reader w illy obt ainis at he g reat erent un der an ding and WAN k ing, ar t icu the rhar easons. I f t h e called par t y endp oint h as no m ore r esour ces, t h e call can not com plet e.ov This dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ided on raesour ce r epor t ing and m anagem en t f unct ionalit y can be p er f orm ed by a gat ekeeper . Of floading b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions rt oesour ce r epor t ing and m anagem en t t o t he gat ekeeper allow s t he g at ek eep er t o m ak e smar en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . t decisions call rext outend in ged if rnesou r cest oarnew e unnavailable. Cov erag e on is also ot only et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Connect pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The Connect m essag e t ells t he callin g p ar t y t hat t he called p art y has an sw er ed t he call, an d t hat v oice p at h cu t - t hr oug h can now com m ence. The Con nect m essage uses a lot of t h e same field s t hat t he Aler t ing and Call Proceed ing messages do, w it h t he addit ion of sev eral mor e. The connect edAddr ess field id en t ifies t o t he callin g p art y t he alias ad dr ess of t h e called par t y t hat answ ers t he call. The p resen t at ionI nd icat or field ident if ies w h et h er t he conn ect edAdd r ess is

show n t o t h e calling p art y .

Release and Release Complete The Release ( REL) an d Release Com plet e ( RLC) messages ar e w here H. 2 25 diff er s m or e signif icant ly fr om I SDN Q.9 31—par t icu lar ly in t he f act t h at H. 32 3 end point s do n ot u se t he REL •m essage: Table of Content s •

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ect / r elease/ r elease com sequence I nt e rn The et w ordkisconn ing Te chnologie s H a ndbook , Four th plet Edit e ion By

is n ot used sin ce t he only ad ded v alue is t hat a net w ork t ou ser inf or mat ion elem ent can b e append ed t o t he r elease m essage. As Cisco Systems, Inc. t his d oes not apply t o t he p ack et - based net w ork env ir onm ent , t h e sin gle st ep m et hod of sen ding only Release Com plet e is used. Pub lish er: Cisco Press Pub Dat e: H. Sep225 tem ber 1 1, 2 003 ion —I TU Specificat

1 1/ 20 00, page 40

I SBN: 1- 58 705 -1 19 -2

Figur ePages: 24 - 511 illust 28 r at es t he sing le RLC sent f r om t he calling par t y t o t he called p art y w hen t he callin g p art y w ant s t o discon nect t h e call. H. 32 3 en dpoint s use t he RLC m essage on ly wh en call t er min at ion is r equir ed.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Figu r e 2 4 -5 . H .2 2 5 Cal l Tea r dow n w i t h an RLC M e ssag e essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Table 2 4-net 5 dwescr ibes e of t h e tfields showand n inan t he Release plet e por m essage's serw - user I E. enables or kin g p rsom ofessionals o un derst d im plem enCom t cont em ar y int erunet ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Tab le 2 4 - 5 . Re le ase Com pl et e M essa ge Fie lds a n d Rel ea se Code s net w or kin g p rof essionals, r egar dless of ex pert ise. Reader w ill a gpt reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Su bhesad ingobtDain e scri i on har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Specifies hy t h escall m inat ed. ing det ailed descr ipt ion s, rev iew quest ions ar eason b r oad r ang e of int egr al wsy st em andwas servt er ices, in clud t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . bu sy Add ress The alias ad dr ess of t h e bu sy called p art y. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s,y pr ovidSpecifies in g a m orteher ealist ic gpict urice' e ofs tcapacit he realor lddif n et or ce k ing virw onm in w hich capacit sendin d ev y.wThe ferwen is en t hat it h ent t h esRLC pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr m essage, t h e capacit y is t he call capacit y of t he send ing device af t er t heease cur r en t pr odu ct iv it y an dcall im pr ovbeeen eff iciency, has r eleasedhelp . ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The f ollow in g list d escr ibes som e of t h e m or e com m on call release cau se codes: noBa ndw i dt h— No chann el is available f or t h e call t o com plet e.

ga t e k ee pe rRe source s— No av ailab le resour ces. un re acha bl eD e st ina t ion — No r out e t o t he dest in at ion. This t yp ically m ean s t hat t her e is no I P pat h t o t he d est inat ion , w het her t h rou gh r out ing or t h e lack of a dial peer . de st ina t i onRe j e ct ion— Norm al call clearing . • •

in va l idR ev ision — The Table of Content s endp oint t hat reject ed t his call is incom pat ible. I ndex

un re acha bl eGat ek e ep er — The gat ek eep er is unav ailable, usually because of a n et w or k inf rast r uct ur e p rob lem .

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

ga t e w a y Re sou rces— There is con gest ion in t he sw it ching equipm ent , t yp ically in t he inat ionPress gat ew ay or endp oint . Pubdest lish er: Cisco Pub Dat e: Sep tem ber 1 1, 2 003

ba dForm a t Addr e ss— I n valid or un recogn ized nu mb er for m at . I SBN: 1- 58 705 -1 19 -2

Pages: in Con 11 f—28The endp oint t hat was requ est ed in t h e Set up m essage is alr eady " in con fer en ce. " The called p art y is busy .

fa cil it y Cal lD e fl ect ion — A nor m al call- clear ing message. secur it y D en ie d— The secu rit y check did not m at ch, and t h e call w as r ej ect ed. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. cal le dP ar t y N ot Re gist e re d/ cal le rN ot Re gist e re d— These m essag es are sent w hen an endp oin t is n ot r egist er ed w it h a gat ek eeper an d a call requ est is sen t or t he endp oin t is not r eg ist w itsh of t he pr oper eeper . t o n et wor k ing pr ofession als at all lev els, f rom Con cise overered v iew t echn ologgat ies ek essen t ial nov ice t o ex pert . ne e ded Fe a t ure N ot Suppor t e d— One of t h e call' s r eq uir ed f eat u r es is n ot sup por t ed b y tNew he called y. chapt perars tinclude cov erag e of im por t ant t opics like VoI P and EAP tCov un erag ne le edSi ngR ej ect e d—ologies H.2 25 lik t un b eenstror eqage uest ed by t he callin g ofgna cut tliing edge t echn e neled opt icalsign naling et wor k has ing and par t y b ut is not su ppor t ed by t h e called par t y. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . H. 225 t u nneled signaling can be u sed for d iff er ent applicat ions. Specif ic t o H.3 23 net w or ks t hat connect wor it hk in t he ser vice pr ov ider SS7 net w orkt,has SS7 call sign alin g hit s t he H.3 23 I n t ern et w g Tech nologies Hand book , Four Edsoon it ion ,as is tah ecom pr ehensive refer ence t hat net w or k, m any SS7 call feat ur es ar e lost . H.2 25 t un neled signaling can b e used t o t u nnel t hing ose enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork feat u res acr oss t he H. 32 3 n et wor k t o be p rov ided at t he called par t y locat ion or bet w een callin t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ingg and called parnt ies. indu st ry . Lear how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Wit t he fast pr com ocedplet ur e,e an chann el can be topened in an 25 tt un to andhin speed, t h is conn bookect is a an dH.u24 p- 5t o-con d att reolr ef er ence t o t he op ics t hat areH.2 essen ial nel t o all rnet ed w uce t he num ber of r equir ed r oun d t rip s bet w een endp oin t s. or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on H.245 a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . H. 245 is u sed bet w een H. 323 dev ices f or sev eral diff erent fu nct ions f or call cont r ol m anagem ent . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy When y ou t hink abou t H. 24 5, capab ilit y ex chang e pr obably com es t o m ind . Alt hou gh t hat is a syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich v er y im por t ant aspect of H. 245 , it is n ot t he only f unct ion t hat is ser v ed w it h H. 245 . Ot h er pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease r espon sib ilit ies of H. 245 ar e m ast er / slave det er m inat ion, con t r ol chann el man agem en t , r ound pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient t r ip delay det er m inat ion, main t en ance loop sign alin g, an d m od e requ est s. decisions for t h eir net w ork s.

Capability Exchange The cap abilit y ex chang e bet w een endp oin t s hap pens b ef or e a logical H. 24 5 cont rol ch annel is

opened bet w een t hem . The cap abilit y ex chan ge ident if ies w h at capabilit ies each endp oint in t h e call pr efer s and can h andle. Cap abilit ies t hat ar e ex ch anged include CODEC list s ( in ord er of pr efer en ce) and vid eo or dat a specif icat ion s if need ed . The cap abilit ies ar e or der ed int o a capab ilit y Table an d t hen in t o an alt ern at iveCap abilit ySet . Th e pu rp ose of t he alt er nat iv eCap abilit ySet is t o ident if y t o t he d est inat ion endp oint ( in eit her dir ect ion ) all t h e av ailab le operat ion al capabilit ies and t o specify t h at on e m ust b e select ed . For inst ance, it w ou ld list all t he supp ort ed aud io CODECs, b ut only one could be select ed for use • Table of Content s fr om t hat set . More t han one op er at ional CODEC at a t im e is n ot sup por t ed. •

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IAft nt eer rn et w oralt k ing s H a ndbook t he ernTe atchnologie iveCap abilit ySet s ,hFour avethb Edit eenion creat ed,

t hey ar e gr ouped int o simu By Cisco lt aneousCapab Systems, Inc. ilit y Set s. These set s ident if y w hich of t he alt er nat iv eCap abilit ySet s m ay b e used in conj unct ion w it h each ot her . For inst ance, t hey m ight ident ify a v ideo and au dio CODEC t hatPub mlish ayer: beCisco u sed t oget h er . Press Pub Dat e: Sep tem ber 1 1, 2 003

Cap abilit ies ar e also g rou ped in t o t r ansm it , r eceiv e, an d t ran smit - r eceiv e gr oup in gs, alt hou gh 1- 58 705 -1 19 -2 t his is IaSBN: logical gr oup ing. These g rou ps ident if y t r ansm it , r eceive, an d cap abilit ies t h at m ust be Pages: 28 h dir ect ion s ( t r ansm it - r eceiv e) . t he sam e in11bot

Master/Slave Determination The pdat ede edit ion of t he selling one ing r efion, erence p rov tides agelict ofs Mastuer/ slav det er minat ionb, est as -set f ort hallb yint he H.net 3 23w ork sp ecificat is used o setcover t le conf essent ial an d cu t t ingedg e t ech nologies. bet w een H. 32 3 end point s. Th e H.3 23 endp oin t s set a t er m inal t y pe t hat id en t ifies w hat t y pe of t er min al t hey ar e, and t hey g en er at e a r andom n um ber t o be d isclosed in t he st at usDet erm inat Num field. Four er ent t erm can be als assigned, sh ow n in Con cise ov erion v iew s ofber t echn olog ies diff essen t ial ttyopes n etof wor k inginals pr ofession at all levas els, f rom Tablenov 2 4-ice 6. t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Tab le 2 4 - 6 . Te r m in al Ty pe s t o Be U se d i n M ast e r / Sl av e De t e r m in at ion Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . rmet inwalorTy V a lue Tabl eHand book , Four t h Ed it ionH, .is 3 2a3 com Te rm in al Ty perefer s ence t hat I nTe t ern k inpe g Tech nologies pr ehensive enables wtor kin g p r ofessionals t o un derst and an d imTe plem t cont em por inteerknet w ork Fea t ur enet Se rm en in al Gat ew ayar yGat e epe r ing MCU t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing En t it h non MC 50 olog ies in60 — env ir onm ent — . indu styryw. itLear how t o incor por at e int er net w or kin g t echn t o a LAN/ WAN Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, En t it y cont ains an MC bu t n o MP 70 80 12 0 16 0 and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net g ains p rof essionals, r egar dless of ex pert ise. Enw t itor y kin cont MC w it h dat a MP — 90 13 0 17 0 En t it y scont MC aw gitreat h dat and ioding MP of LAN and—WAN n et w10 0 lar ly t h e 18 0 Reader w illains obt ain era un deraud st an or k0 ing, p ar14 t icu har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on En t it y cont ains MC w it h dat a, audio, an d video MP — 11 0 15 0 19 0 a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t oTable en sutre confrcept r eh en vsion and4,r et en00 t ion, and 27 ad dit ional r esou r ces f or fu rt her st udy . ak en om comp I TU H. 323 er sion 1 2/ , page Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease The p ur pose of t his t able is t o id en t ify w h ich t erm inal t y pes t ak e pr iorit y ( becom e t h e m ast er ) . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient En t r ies t h at h ave a—id en t ify t h at t er m inal t y pe' s inabilit y t o use t he list ed f eat ur e set . The decisions for t h eir net w ork s. endp oin t w it h t he higher v alue f r om t he t able as t er min al t y pe b ecom es t he m ast er for t he connect ion. I t is possib le for an endp oint t o be t he m ast er in on e connect ion an d a slave in anot h er . I f t h e t w o t er m in al t y pes ar e t he sam e, t h e en dpoin t w it h t he h igher f eat u re set becom es t he m ast er . On e of t he m ain uses of t he m ast er/ slav e det erm inat ion is deciding t he pr ef er r ed or d er of it em s,

such as audio CODECs. For exam ple, if t h e mast er list s t he ord er of pr ef er ence as G.7 23 and t hen G. 72 9, b ut t he slave h as an or dered list of G. 729 an d t h en G. 7 23, t he slave sh ould reor der it s CODEC pr efer en ce t o m at ch t hat of t he m ast er en dpoin t .

Control Channel Management •Aft er t he exchan Tablege of of Content s ilit y an d t he ident if icat ion of t he mast er and slav e en dpoint s, H.2 45 capab •opens a cont Ir ndex ol chan nel. The logical cont r ol ch annel is u sed for cont rol message t r anspor t and is Ialw nt e ays rn et wassign or k ing ed Te chnologie s Hchan a ndbook Four th Edit ion nel r emain s open unt il t he call' s t er m in at ion. as logical nel, 0. That chan H. 245 is also r esp onsible for closing t he con t rol ch annel w h en necessar y. By Cisco Systems, Inc.

Figur e 24 - 6 sh ows t he st eps t h at t y pically t ak e place dur ing a call set up negot iat ion . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 2 4 -6 . H .2 4 5 Cal l Se t u p M e ssa ges

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The con t rol ch annel is op en ed u sing t h e openLogicalChannel m essag e. Because v oice is t he m ost I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat com mon app licat ion of H. 323 , w e w ill focus on t h e pr oced ur e for voice t r anspor t . W hen au dio is enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t o be used wit h an RTP st ream , t h e m ed iaCont r olChan nel par am et er is in clu ded w it h t h e t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing openLogicalChann el message. The f or war d m ed iaCont r olCh annel m essage in clu des t he ad dr ess indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . of t he rev er se RTCP chann el. The r eceivin g end point replies w it h an op en LogicalChan nelAck t hat Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, cont ains t he m ediaTr anspor t Chan nel and t h e m ed iaCont r olChan nel. The m ediaTr anspor t Chan nel and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all cont ains t he RTP t r anspor t ch annel f or t he m edia ch annel, and t h e m ed iaCont r olChan nel net w or kin g p rof essionals, r egar dless of ex pert ise. cont ains t he t r anspor t addr ess for t he f orw ar d RTCP ch annel. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Round-Trip Determination a b r oad r ang eDelay of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov e ist ralso ext end n ot only o new k ing t s, sbut oldnet er , wlegacy The erag r ou ndip delay deted erm inat ion tser v es tnwetowor d if fer entconcep f un ct ion in talso he H.t o323 or k . I t syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent w hich ident if ies t h e r ound - t r ip d elay b et w een t he endp oin t s, and it v er if ies t hat t he r em ot e senindpoin t is pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease st ill fu nct ional an d com m unicat ing w it h t he H. 32 3 n et wor k . This f un ct ion can be used as a t y pe pr ct iv it y an pr ov e eff help akenet mor in t elligent , cost - eff icient of odu " hear t beat " tdo im v erif y net w iciency, or k operat ioning w itt he hinr eader t he H.3m23 w ore k. decisions for t h eir net w ork s.

Maintenance Loop Signaling The m aint en ance loop sign alin g m et hod in H.2 45 let s t he cont rol ch annel p er f orm loop s t o pr ov ide t est ing t o t h e net w or k. Thr ee diff er ent t yp es of loop s ar e specif ied :

Sy st em — Refers t o all p r esent log ical ch annels. Me di a — The m edia st r eam t hat is used b y t he call. Log ical cha nne l — A loop of a specif ic logical chann el. •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

NO TE

By Cisco Systems, Inc.

H. 323 specif ies only t he use of a m edia loop. The sy st em an d log ical ch annel loops are Pub mlish ar er: kedCisco as Press for bid den. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Mode Request The m od e r eq uest is t he r eceiv ers' abilit y t o requ est t he m od e t hat t he t r an sm it t er s w ill use. The t w o m et hod s av ailab le t o end point s ar e u nicast and m ult icast . Un icast is u sed in point - t o- point The u pdat edin edit ion of tions, he b est - selling all- inrov ides age of H. 323 t er m al connect and m ult icast is one usednet in w H.ork 32ing 3 t err ef merence inal- t o-pMCU con cover nect ion s for essent ial anor d cu t t inge t ech nologies. cen t r alized decen t redg alized confer en ce requ est s. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

RTP nov andiceRTCP t o ex pert .

Real- tNew im e chapt pr ot ocol er s (include RTP) , also cov erag called e of realim tpor im e t ant t r anspor t opicst like pr otVoI ocol, P and is responsible EAP f or cr eat ing t h e av en ues t hat t he medium ( audio, video, or dat a) t akes. RTP is ident if ied by t h e I nt er net Coving eragTask e of For cut tce ing( I edge t echn e opt ical next et wor k ing st323 or age En gineer ETF) in RFCologies 18 89. lik RTP is used en siv elyand in H. n et w or k s along w it h RTP Cont r ol Pr ot ocol ( RTCP) f or bot h u nicast and m ult icast oper at ion. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . RTP st ream s bet w een end point s ar e u nidir ect ional. Bid ir ect ional com mu nicat ion r equ ir es an RTP I nrt eam ern etin w or k in nologies Handnbook , Four t h -Ed st b ot h gd Tech irect ions, as show in Figur e 24 7. it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it hFigu new ran chaptSt errsea on m secur it yd , stt or opt ical net we orct k in g, scalabilit y, e d2u4pdat -7 .edRTP s an heage, RTCP Conn i on and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figur e 24 - 7 also sh ows t he RTCP conn ect ion. RTCP is used t o r ep ort t o en dpoint s on t he qu alit y of dat a dist r ib ut ion t hat is pr ov ided on t h e lin k. RTP st r eam s ar e opened on ev en UDP p or t nu mb er s t hat ar e in a r an ge of un used por t num b er s. RTCP uses t he next - h igher od d UDP por t in

t hat sam e ran ge. En dpoint s t hat ar e en gaged in a connect ion u sin g RTP f orm an RTP session. This RTP session includes d est inat ion t r anspor t addr esses for each par t icipant in u nicast confer ences or a com m on dest inat ion t r anspor t ad dr ess in m ult icast confer ences. A dest in at ion t ran sp or t add r ess consist s of a n et wor k ad dr ess an d a pair of p ort s for RTP an d RTCP. So, f or a unicast conf er ence bet w een endp oin t s, each endp oint has it s ow n net w or k addr ess but shar es t he sam e por t pair f or RTP and RTCP. •

Table of Content s

•RTP does notI ndex pr ov id e a m echanism f or QoS. I nst ead, it r elies on ot her pr ot ocols, such as Ir nt e rn etce w or k ing vat Te chnologie H a ndbook , Four esour r eser ion pr otsocol ( RSVP) . th Edit ion By Cisco Systems, Inc. Pub lish er: Cisco Press H.450 Pub Dat e: Sep tem ber 1 1, 2 003 SBN: 1- 58of 705sp -1ecificat 19 -2 H. 450 Iis a set ions t hat w er e designed t o of fer serv ices t o t he en d u ser s in an H. 3 23 11 28 ser vices ar e int ended t o em ulat e t he ser v ices t h at ar e of fer ed in t he ser vice net w orPages: k. These pr ov ider' s SS7 net w or k so t hat pr ov iders of H. 3 23 can com pet e w it h ex ist in g ser vices in t he PSTN. Table 2 4- 7 d escr ibes t he H. 45 0 sp ecificat ions an d t heir uses.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Tab le 2 4 - 7 . H.4 5 0 Se r vi ce s I ssue d f or Cust om e r Use

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Sp ecif ica t ion N a m e D e scri pt i on nov ice t o ex pert . H. 450 .2 Call t ran sf er Tr ansfer s calls fr om one en dpoint t o anot her . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP H. 450 .3 Call r edir ect ion Redir ect s a call fr om on e endp oin t t o anot h er . Th is ent ails t he kcall ef or st e or answ Cov erag e of cut t ing edge t echn ologies lik er ed optirect ical ing n et wor ing band ageer ing . H. 450 .4h ored byCall h old t he call in w a or hold o be sweter Aut Cisco Sy st ems, w or ldwPlaces ide leader in net kingstfat ore tthe I n tan er n . ed lat er fr om t he sam e end point . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat H. 450 .5 Call p ar k Places t he call in a hold st at e t o be an sw er ed f rom t he enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing sam e en dpoint or a diff erent endp oin t . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry.6. Lear n how incor or kin olog in t o ag LAN/ env ir onm ent . H. 450 Call two ait ing por at e int er net Thewab ilit yg ttoechn r eceiv e ies incomin call nWAN ot ificat ion as soon Com plet e w it h new an d u pdat ed chapt eras s on secur it y been , st or age, opt ical on netan w orend k in point g, scalabilit y, a call has est ablished . and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all H. 450 .7 g p rof essionals, Messag e Wait ing Specifies net w or kin r egar dless of ex pert ise. t hat a m essage is w ait in g f or t h e user. I ndicat or ( MWI ) Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e H. 450 .8 Nam e ident ificat ion I dent if ies t h e user w ho is placin g t h e call ( calling p art y har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on ( caller I D) ident if icat ion) . a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t oH.en su.9 re con ceptCall comp r eh enion sion and r et en t plet ion, es and ad dit r esou r ces fu rt herofstaudy . 450 com plet Com a call t hional at w as r eject edf or b ecause busy Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy endp oin t af t er t hat endp oin t b ecom es available. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich .1 0 Call fer Decid w het her t osyst answer t hfor e call or r w eject t heease call prH.of450 essionals oper at e.ofTools and gu id elines f oresopt im izing em per m ance ill incr aft er anot her call has been est ablish ed . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions netinwtork s. H. 450 .1 1for t h eirCall ru sion I nt er ru pt s a call bet w een par t ies in an H. 32 3 call t o place a new call w it h eit her of t h e t w o inv olv ed par t ies.

Audio CODECs

Aud io COD ECs ar e u sed t o t ran sp or t aud io ( t y pically voice) at var y ing comp ressed bit r at es. A CODEC is a v ery im p ort an t ad dit ion t o t h e t r anspor t of VoI P net w ork s b ecause it allow s m or eeff icient use of r esour ces.

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NO TE Table of Content s I ndex

I nt e rnTher et w orek ar inge Te chnologie s H a ndbook , Four ion on ym sev eral w ays t o int er pr ettht hEdit e acr

CODEC. Som e say it st an ds f or an d ot hers say it st ands for com pr ession/ d ecom pr ession. Alt h ough t hey ar e bot h cor rect in t heir ow n r ight , CODEC in t he con t ex t of H.3 23 is m ore app riat ely t h ough t of as com pr ession/ d ecom pr ession. Pub lish rop er: Cisco Press

coder/ decod er , By Cisco Systems, Inc.

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: CODECs are11p28 r ocessed by d igit al signal pr ocessors ( DSPs) w it hin t he f abr ic of t he H.3 23 har dw ar e. DSPs ar e d ev ices t hat ar e u sed t o pr ocess digit al sig nal f orm s at v er y h ig h sp eeds.

I n a legacy TDM- b ased net w or k, a v oice call u ses a sin gle 64 - Kbps chan nel called a d igit al signal level 0 ( DS0 ) . A v oice call does not r eq uire t he u se of all 64- Kb ps, bu t because no m et h od is in place t o reallocat e unu idt h, ex cess b andw h is w ast The u pdat ed edit ion of sed t he ban b estdw - selling allin- one netidt w ork ing r efed. erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. A st an dar d call in H. 323 also u ses w hat is equiv alen t t o a 6 4- Kbp s chann el by defau lt . The most basic of CODECs is t he G. 7 11a or G. 71 1u COD EC. Th ey sp ecify t hat voice calls use a f ull 64 Kb ps in eit hCon er Alawov(er E1) or smofu-tLaw T1 ) ies comessen pandtin if wor 24 DS0s wofession or t h of tals r affat ic all ar elev suppor ed on cise v iew echn(olog ialg.t oSon et k ing pr els, f trom a g at eway , t there can .be a m axim um of only 24 v oice calls. nov ice o ex pert CODECs b r oken int o t wocov grerag oup s—medium comt opics plexit ylike and com plex it y. Th ese g rou ps Neware chapt er s include e of im por t-ant VoIhighP and EAP ident if y how com plex t he alg orit h m is t h at is used for t he CODEC. Hig her- com plex it y CODECs t ak e m or erag e pr ocessin powedge er t han m ed ium - com lex it y COD ECskan t herefor e, t y pically allow Cov e of cutgt ing t echn ologies lik epopt ical n et wor ingd,and st or age few er calls on t h e same H.3 23 device. Medium - com plexit y CODECs allow fou r calls per DSP, Aut hhighoredcom by Cisco st ems, wallow or ldwonly ide leader in net or kingTable f or t he er ns et w her eas plexit ySyCODECs t wo calls perwDSP. 2 4-I8n tlist t h. e m ed iu m and hig h- com plex it y CODECs and t heir ind iv idu al comp ression r at ios. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com pletle e w2it4h- new an d upl pdat er sps on fsecur it y ,DECs st or age, opt ical net w ortkeindg, Bit scalabilit Tab 8 . Com exed it ychapt G r ou or CO a nd Associa Ra t ey,s and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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COD EC

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H a ndl ing D e la y in m s

G. 71 1 A- law and m u- law

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Table of Content s

• G. 72 3. 1 MP-I ndex MLQ

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

G. 72 3. 1 ACELP

High

5. 3

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G. 72 3. 1 Annex A MP- MLQ ( VAD)

High

6. 3

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Pub lish er: Cisco Press G. 72 3. 1 Annex A ACELP ( VAD)

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G. 72 8I SBN: LD- CELP 1- 58 705 -1 19 -2

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Less t han 2

G. 72 9Pages:

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G. 72 9B

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G. 72 9 An nex B ( VAD )

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By Cisco Systems, Inc.

Pub Dat e: Sep tem ber 1 1, 2 003

11 28

ACELP— raic Lin earallPr inedict ionnet w ork ing r ef erence p rov ides cover age of The u pdat Alg ed eb edit ion Codeof t heExb cit ested - selling one essent ial an d cu t t ing- edg e t ech nologies. LD - CELP— Low - Delay Code- Ex cit ed Lin ear Predict ion CS- ACELP— St ru ct u rolog e Algebr aic CodeearprPredict ionals at all lev els, f rom Con cise Conj ov er vugat iew se of t echn ies essen t ial t oExncit et ed worLin k ing ofession nov ice t o ex pert . MP- MLQ— Mult ipulse Mu lt ilev el Quan t izat ion New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . NO TE I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat G. 72 9 ( g72 9r 8) is t he def ault CODEC in t he Cisco I OS. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w G. it h729 newAnan d uB pdat chapt s on secur it ye, st or age, k in.g,This scalabilit Not ice t hat nex andedG.7 23. 1erAnnex A hav " VAD" listopt ed ical nextnet t owtor hem m eansy, and speed, t h is book is a com plet e an d u pt od at e r ef er ence t o t he t op ics t hat are essen t ial t o all t hat v oice act iv it y det ect ion is int eg rat ed int o t he CODEC and cann ot be disabled . net w or kin g p rof essionals, r egar dless of ex pert ise. VAD is a f eat u r e t hat helps t h e H.3 23 net w or k devices use ban dw idt h m or e ef ficien t ly. For Reader s wifillt w obt a g reat un der ding w or k ing, p aret icu ly ttim h ees in exam ple, o ain people ar e er t alkin g t st o an each ot of h erLAN overand an WAN H. 323n et net w or k , t her w illlarbe har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov t his con ver sat ion du r in g w h ich neit her p art y is sp eak ing . Keep in min d t h at t h e t r anspor tided on a b rwoad ang intrast egr al syur ste, eman sd and serv ices, ingover det ailed descr ionI s, net or k ris ane Iof P inf r uct ev en silen ceinisclud sent t he net w oript k as P prev ackiew et s.quest For ions tnet o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy w or k inf rast r uct ur es t hat pay on a per - packet basis, t his is cause for con cer n, becau se it. Cov e is ey also w asterag es mon . ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals Tools band guect id elines opt imand izingsup syst per for VAD allev iat esoper t hisatpre.oblem y det ing t h ef or silence prem essing anympance ack etwsillfr incr om ease bein g pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost effed icient sen t d ur ing t hose per iods. Dur ing t h ese p er iods of inact iv it y, com f ort noise is gener at on t h e decisions forit tdoes h eir net ork nd s. as if t he call h as been d isconn ect ed. Figur e 24 - 8 illust r at es t he call so t h at notwsou basic dif fer en ce bet w een devices w hen VAD is used and w hen VAD is t u rn ed of f.

Figu r e 2 4 -8 . H .3 2 3 Cal ls w it h an d W i t h out VAD

[ View full size im age]

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Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Not all CODECs int er oper at e. Gr eat car e m ust be t aken t o en su re t hat t he pr op er CODECs ar e selectCon ed on cisebot ovherend v iew s sofoft he t echn conn olog ect ies ion.essen I f t het ial CODECs t o n et wor t hatk ing are pr select ofession ed do alsnot at all m atlev chels, or ar f rom e incomnov patice ible, t ot h exepert call . set up f ails. I f t h e rem ot e CODEC is un kn ow n, CODEC classes can b e creat ed in Cisco I OS t o allow CODEC n eg ot iat ion t o occu r bet w een endp oint s. Con figu rat ion of New chaptis er cov s include cov e ofchapt im por opics VoI P andt hat EAPcan in t er oper at e: CODEC classes er ed lat ererag in t his ert.ant Hert e ar e like t he CODECs Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age G. 72 9 an d G. 729 A Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . G. 72 9 an d G. 729 I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables G. 72 net 9A w or ankin d G. gp 729 r ofessionals A t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing 9 Annnex d G. 729A B w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . indu stG. ry72 . Lear howB tan o incor por at Ann e intex er net Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, G. 72 9 tAn B an 729 Ann exdBu p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all and speed, h isnex book is da G. com plet e an net w or kin g p rof essionals, r egar dless of ex pert ise. G. 72 9A An nex B an d G.7 29A Annex B Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e 5. 3 Kbps) 723 .1olv ( 6 ed .3 .Kbp s) har dwG. ar72 e, 3. pr1ot( ocols, and an serdvG. ices inv Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions G. 72 3. 1 ( 5. 3 Kbps) an d G. 723 .1 ( 5 .3 Kbp s) t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e 3. is 1also end edanndotG. only et wor G. 72 ( 6. 3ext Kbps) 723 t.1o new ( 6 .3 nKbp s) k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals at e. and f or ems)per for m ance w ill incr ease G. 72 3. 1 oper Annex A Tools ( 5. 3 Kb ps)gu aniddelines G. 723. 1 opt Annim exizing A ( 6.syst 3 Kbp pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions eir netAw(ork G. 72for 3. 1t hAnnex 5. 3s.Kb ps) an d G. 723. 1 Ann ex A ( 5. 3 Kbp s) G. 72 3. 1 Annex A ( 6. 3 Kb ps) an d G. 723. 1 Ann ex A ( 6. 3 Kbp s) As is t h e case w it h any voice net w or k ( I P or ot herw ise) , delay is a v ery im p ort an t issue. Too m uch delay in t h e net w or k causes p oor , choppy voice qu alit y and possib ly ev en call d rop s and

disconnect s. Ther e are t w o gener al t y pes of delay ( t y pically m easur ed in m s) —pr opag at ion d elay and han dling delay. Pr opagat ion delay is ex perienced as dat a is t ran sm it t ed fr om on e locat ion t o anot her . I t is sim ply t he amou nt of t ime it t ak es t he inf or mat ion t o t r aver se t he n et w or k . Hand lin g d elay is t he am ount of t im e t hat endp oin t s t ak e t o pr ocess t he in for m at ion. For exam ple, t h e am ount of t im e t hat is r eq uir ed t o com pr ess or decom pr ess t h e call w it h a COD EC • of Content s is a handling Table d elay . Table 2 4- 8 list s t h e comp ression or h andling delay f or each CODEC. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

H.225 RAS

Pub lish er: Cisco Press

Gat ek eeper s and dir ect ory gat ekeepers are opt ional com pon en t s t hat allow t he H.3 23 net w or k t o Pub Dat e:mSep ber 1 1,b2y003 be scaled or etem easily cent ralizing H. 323 endp oint man agement . Gat ek eeper s use t h e su it e of I SBN: 158 705 -1 19 -2 in t h e H. 225 specif icat ion t o comm un icat e wit h each ot her as w ell as RAS messages ident ified Pages: w it h H.3 23 11 en28 dpoin t s. Ear lier in t his ch apt er, H.2 25 w as m en t ioned as a p rot ocol u nder t h e H. 323 um b rella. I t is separ at ed f r om H. 225 in t his chap t er becau se of it s applicat ion in H. 32 3 net w or ks. How ev er , H. 22 5 RAS is act ually p art of t he H. 22 5 sp ecificat ion; it is n ot a sp ecific subsect ion . Tw o m ain t y pes of gat ek eeper signaling ar e w idely used—dir ect ed call sig naling and gat ek eeper The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of r out ed sig naling ( GRS) . Direct ed sign alin g u ses t h e gat ek eeper f or dest inat ion locat ion bu t r elies essent ial an d cu t t ing- edg e t ech nologies. on t he g at eway s t o set up t he calls b et w een end point s. GRS u ses t h e gat ek eeper s for en dpoint locat ion as well as f or t h e call sig naling pat h. The easiest w ay t o t ell t he diff er ence bet w een t h em is t hatCon dircise ect ed s only RAS m essage m unicat bet w een ew els, ay and ovsignaling er v iew s ofshow t echn olog ies essen t ial t o com n et wor k ing ion pr ofession alst he at gat all lev f rom gat eknov eeper H.pert 22 5. call set up) . ice (tnooex New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

NO TE Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Becau se Cisco gat ekeeper s su ppor t only t h e dir ect ed call sign alin g m et hod , t his I n t ern or k in Techfnologies , Four t h flow Ed its. ion , is a com pr ehensive refer ence t hat metetwhod isgused or all subHand sequbook en t RAS call enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Table 2 4-e 9wlist t h e an RAS essag t y pes het her sedical for net gatw ew o- scalabilit gat ekeeper Com plet it h snew d umpdat ed echapt erand s onwsecur it y ,t hstey or are age,u opt orayk intg, y, com mu nicattion 1 ) , gat eep er - t oayt ocom ion ( t2) or gat t o- gat ek eeper and speed, h is (book is ek a com plet eg anatdew u pd atme unicat r ef er ence o ,t he t op ekeeper ics t hat -are essen t ial t o all com nicat (3). net wmu or kin g pion rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con Tab cept lecomp 2 4 -r9eh. en RAS sion M and e ssa r et en ge t ion, Typ and esadadit nd ional M er esou ssag r ces e Dir f or e fuct rt her ionst udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich RAS Me ssa ge Me ssa ge N am e Com m un icat ion D ire ct ion pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease prGRQ odu ct iv it y an d imGat pr ov eff iciency, help ing t he r eader m ake mor1e in t elligent , cost - eff icient ekeeeper Req uest decisions for t h eir net w ork s. GCF Gat ek eeper Confir m 2 GRJ

Gat ek eeper Rej ect

2

•

RRQ

Regist r at ion Req uest

1

RCF

Regist r at ion Conf ir m

2

RRJ

Regist r at ion Rej ect

2

Unr eg ist r at ion Request

1

I ndex Unr eg ist r at ion Conf ir m

2

URQ

Table of Content s

• UCF

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

URJ

Unr eg ist r at ion Reject

2

By Cisco Systems, Inc.

Pub lish er: ARQ

Cisco Press Adm ission

Requ est

1

Con fir m

2

Pub Dat e: Sep tem ber 1 1, 2 003

ACF ARJ

LRQ

Adm I SBN: 1- 58 705 -1 19 -2ission Pages: 11 28

Adm ission Reject

2

Locat ion Request

3

LCFu pdat ed edit ion Locat m 3 The of tion he bConf est - ir selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ingedg e t ech nologies. LRJ Locat ion Reject 3 RI P

Requ est I n Pr ogr ess 2 Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

DRQ Disen gage Request 1 or 2 New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP DCF Disen gage Conf irm 1 or 2 Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age DRJ Disen gage Reject 1 or 2 Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat BRQ Band wid t h Chang e Requ est 1 enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast Band er t hewid t ert hm Chang s, con cep t s, fir t echn BCF e Con m ologies, an d devices 2 used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . BRJplet e w it h newBand t h Chang e Reject 2 ical net w or k in g, scalabilit y, Com an d wid u pdat ed chapt er s on secur it y , st or age, opt and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. I RQ I nf orm at ion Request 2 Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e I RR I nf orm ion Response 1 har dw ar e, pr ot ocols, and at ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on aI ACK b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions I nf orm at ion Ackn owledg ment 2 t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . I NACK I nf orm Neg at Acknnow ledgm 2 also t o old er , legacy Cov erag e is also ext end edatnion ot only t oive new et wor k ing ent concep t s, but syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease prRAI odu ct iv it y an d imResour pr ov e ce eff Availabilit iciency, help t heorr eader m ake mor1e in t elligent , cost - eff icient y I ing ndicat decisions for t h eir net w ork s. RAC Resour ce Availabilit y Con fir m 2

As y ou can see, t here is a pat t er n w it h RAS m essages. Requ est , Conf ir m , an d Rej ect ar e t he t hr ee pr im ar y message t y pes t h at ar e used, w it h t he ex cep t ion of in for m at ion- gat h er ing

m essages.

Gatekeeper Discovery Gat ek eeper d iscov er y is t h e pr ocess in w hich t he gat ew ay locat es t he g at ek eeper. Bef ore t he gat ew ay r egist er s w it h t he g at ekeeper, discov ery mu st be p er f orm ed. Typ ically, t his can be •accom p lishedTable of Content in t wo w ays.s Th e gat ew ay can locat e t he gat ek eep er b y a u nicast r eq uest or b y a •m ult icast r eqIuest ndex , as show n in Figur e 24 - 9. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

I f a u nicast GRQ is sen t , t h e receiv ing gat ek eep er r espond s dir ect ly w it h eit h er a GCF or GRJ t o t he r equest ing gat ew ay .

Pub lish er: Cisco Press Pub I fDat am e: ult Sepicast tem berGRQ 1 1, 2 003 is sent ,

only a g at ek eeper t hat w ant s t o gr ant t he gat ew ay discov ery r espon ds it -1 h 19 a -2 GCF. I f no suit ab le gat ek eeper is p resen t , no r espon se is mad e. I f m or e I SBN: 158 w 705 tPages: han on 11e28gat ek eeper r esp onds, t h e fir st r esp onse r eceived is used.

Figu r e 2 4 -9 . Un icast a n d M u lt ica st Ga t e k ee pe r Di scove r y The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tGateway o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Registration Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Gat ay r egist rat ion t h e prand ocess inelines w hichf or t h eopt H.im 323 gatsyst ew ay er m sw it h tw heillgat ekeeper pr ofew essionals oper at e.isTools gu id izing emr egist per for ance incr ease and t ells t he g at ekeeper about all t h e num b er s or ad dr esses it is r esp onsible for . I f an RRQ h as pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient been sent for t o at hgat eeper f r om a g at ew ay , t h e discov er y pr oced ur e has com plet ed . The RRQ is decisions eir ek net w ork s. answ ered w it h an RCF t o con fir m t he addit ion of t he g at eway or an RRJ t o d ecline it . The g at ekeeper can d ecline r egist rat ion f or sev eral r easons, n ot t h e least of wh ich is secu rit y . Gat ek eeper s can be conf ig ur ed t o accept or decline r eg ist r at ion s based on t he requ est er 's sub net or specific I P ad dr ess, am ong ot her t h ings.

Gat ew ay r egist rat ion has been im pr oved sin ce H.3 23 v er sion 1 . I n v er sion 1, t he gat ew ay r eq uir ed a regist r at ion ev ery 30 seconds, w h ich could con su m e con sid er able b andw idt h in lar ge net w or ks. H. 32 3 ver sion 2 inst it ut ed a n ew regist r at ion met hod called light weigh t r egist rat ion . I t r eq uir es t hat a gat ew ay send a p art ial regist r at ion aft er t h e init ial r eg ist r at ion is comp let e. Th e caveat is t hat no ch anges m ay be mad e t o t he gat ew ay conf igur at ion. Ot her w ise, a full r eg ist r at ion is again r eq uir ed . •

Table of Content s

Gateway Unregistration • I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

IByf aCisco g at Systems, ew ay w an t s t o u nr egist er f r om it s gat ek eep er , it m ust send a URQ t o t he gat ek eep er . For Inc. t he gat ew ay t o u nr eg ist er , it mu st r eceive a UCF in respon se. I n t he case of a g at ekeeper failur e, r ecov ery m easur es sh ould be inst it ut ed t o allow t he g at ew ay t o r eg ist er w it h a d iff er ent Pub lish er: Cisco Press gat ek eeper af t er a t im eout or failov er. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 Call Admission

Aft er t he r egist rat ion pr ocess h as successfully com plet ed , t he gat ew ay is r ead y t o p lace calls. For calls placed bet w een gat ew ay s using t he sam e g at ek eep er , t his is k now n as an int r azone call. Figur e 24 - 10 illust r at es t he pr ocedu re t hat is used f or gat ew ay s t o p lace calls using a The u pdat gat ek eepered . edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. St e p 1 . When a call is p laced, t he gat ew ay sends an ARQ t o it s local gat ek eeper . The ARQ is used t o ask per m ission t o place t h e call. Th e gat ek eeper can block t he call an d send an Con ov er v tiew of tt echn olog essen t ial t obnack et wor ing pr ofession lev els, rom ARJcise or allow h e scall o com pleties e by sending an kACF. Em beddedalsinat t hall e ARQ is t fhe nov ice t o ex pert . r eq uest ed H. 323 alias or n um ber . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

NO TE

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . A com m on way t o u se a gat ek eeper is t o use it for b andw idt h cont r ol. On m any I n t ern et w or k in Tech s, nologies Hand h Ed ion , as is aband comwpr t hat gat ekgeeper y ou can set book limit s, Four for ittem s it such idehensive t h or numrefer b er ence of calls per enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w gat ew ay . For exam ple, if Gat ew ay A is allow ed t o place on ly sev en concur r en t ork ing t echnologies. Mast t he er m s,sends con cep t s, t an echn ologies, d devices used. in t oday ' s net w ork ing calls, t heergat ek teeper back ARJ on t h eaneig ht h r eq uest indu st St ry .e Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN onm ent p 2 . I n t his case, t he call is allow ed t o pr oceed. Th e gat ek eeper look s atenv t heirincom ing. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, call r eq uest and look s for t he called nu mb er - t o- I P addr ess m apping t h at is st or ed in it s and speed, book is a The com plet e an d is u p-built t o- das at egat r efew er ence t o ist t he opitics t hatg at are essen tand ial t o all dy namt hicisdat abase. dat abase ay s r eg er t w h t he ek eeper net w orident kin gifpyrof essionals, r egar dless of ex pert ise. w hich n um ber t hey ar e r esp onsible for . Af t er t he p r oper gat ew ay I P ad dr ess h as been locat ed, t he gat ek eep er r et ur ns t hat in for m at ion, em bedd ed in t he ACF, t o t he Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e or iginat ing gat ew ay . har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions St e p 3 . The or igin at ing gat ew ay t ak es t he ACF an d at t emp t s t o set up a call dir ect ly t o t h e t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . r em ot e gat ew ay. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich St e p 4 . Upon receip t of t h e call set u p r equest , t h e t erm inat in g g at eway send s a Call pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Pr oceeding r esp onse back t o t he or iginat in g g at ew ay . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. St e p 5 . Befor e sen ding t he Aler t ing or Con nect m essages t o t he or igin at in g gat ew ay, t he t er min at in g gat ew ay also has t o qu er y t h e gat ek eeper w it h an ARQ t o ask f or per mission t o answ er t he call. The b andw idt h const r aint s can w ork on b ot h in boun d and out bou nd calls, so t he g at ew ay m ust m ake sur e t hat it is allowed t o accept t he call. St e p 6 . The g at ekeeper r espon ds w it h an ACF, allowin g t h e t er minat in g gat ew ay t o accep t

t he in com ing call. St e p 7 . The t er m inat ing gat ew ay sends t he Alert in g m essag e back t o t he or iginat in g gat ew ay . St e p 8 . The t er m inat ing gat ew ay sends t he Con nect m essage b ack t o t h e or ig inat ing gat ew ay . • •

Table of Content s

St e p 9 . The H. 2 45 ex chang e occu rs. I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

St e p 1 0 . The RTP st r eams and RTCP con t r ol chann el are opened f or v oice p at h cu t -

By Ciscot hr Systems, ou gh. Inc. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

FiguI SBN: r e 21-458-1 7050 -1.19Ca -2 ll Adm issi on Re que st ( ARQ ) Pr oced ur e f or I nt r az one Cal ls Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kinTE g p rof essionals, r egar dless of ex pert ise. NO Reader s wlist ill obt ainions a g reat er st unep. derHow st anev ding LAN and or k ing, p ar t icu lar ly t hee is This m ent ev ery er, of rem emb er tWAN hat ifntet hew fast connect pr ocedur har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ovsided on used, t h e H. 225 and H. 24 5 sequences ar e comb ined, an d t h e nu mb er of rou nd t r ip a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions bet w een endp oint s is r educed. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Location pr odu ct iv it yRequest an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. I f t he called n um ber is not ser v ed by t he local gat ek eep er , it m ig ht be necessar y for t he local gat ek eeper t o qu er y a rem ot e g at ek eep er t o f ind t he t er m in at ing endp oin t . Becau se t he call is passed t o anot h er gat ekeeper, it is said t o be an in t er zon e call. Th e m essage t h e gat ek eeper sen ds t o t he r em ot e gat ek eeper is in t he for m of an LRQ. An LRQ is a gat ek eeper 's w ay of sayin g, " Th is is not one of m y nu mb er s. Do y ou k now w here it is?" Figur e 24 - 11 illust r at es t he

pr oced ur e f or int erz one callin g.

Figu r e 2 4 -1 1 . I n t e r zon e Ca ll in g Usin g Gat ek e epe r s

•

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . NewTE chapt er s include cov erag e of im por t ant t opics like VoI P and EAP NO Cov erag ingt he edge echn likRTP, e opt RTCP) ical n etwwor k ingbeand st or age The f inal estof agcut es tof call t set u pologies ( H.2 45, ill not ment ion ed again and ar e assu med t o com plet e successfu lly . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat St e p 1 . The or igin at ing gat ew ay sen ds an ARQ t o it s gat ekeeper. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing St e p 2 . The g at ekeeper ident ifies t h at t h e dialed n um ber belongs t o a r em ot e g at ek eep er indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . and sends an LRQ t o t h e pr oper gat ek eep er . At t he sam e t im e, t he g at ekeeper sen ds a RI P Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, m essage t o t he orig in at ing gat ew ay t o not ify t he gat ew ay t h at it is in t h e pr ocess of and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all locat ing t he p rop er en dpoint . The p ur pose of t he RI P m essage is t o k eep t he call f r om net w or kin g p rof essionals, r egar dless of ex pert ise. t er min at in g or t im in g out b ef or e a r esponse is r eceived fr om t he r em ot e gat ekeeper. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e e ppr3 ot . The t er and m inat ing gat ek s at t ent he in LRQ inf anor d mat lookion s f oris tpr heovcalled har dw St ar e, ocols, ser v ices inveep olv er ed .look Fu ndam al com t eching nology ided on nu mb er t oI P addr ess m apping t h at is st or ed in it s dy nam ic d at abase. Aft er t h e pr operions a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest gat ew ay I P ad dr ess h as been locat ed, t h e gat ek eeper r et ur ns t hat in for m at ion, em bedded t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . in an LCF, t o t he or iginat in g g at ekeeper. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich St e p 4 .oper The at ore. igin at ingand gatgu ekeeper he LCF intem o an sends it t oease t he pr of essionals Tools id elinest r fanslat or optes imtizing syst perACF for mand ance w ill incr or iginat ing gat ew ay . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. St e p 5 . The or igin at ing gat ew ay t ak es t he ACF an d uses it t o set up a call dir ect ly t o t h e t er min at in g gat ew ay. St e p 6 . The t er m inat ing gat ew ay r equest s per m ission t o answ er t he call u sin g an ARQ of it s ow n.

St e p 7 . The t er m inat ing gat ek eep er allow s t h e t erm inat in g g at eway t o an sw er t he call by sen ding it an ACF. St e p 8 . The t er m inat ing gat ew ay com plet es t he call signaling pr ocess an d set s u p t he call.

Call Disengage •

Table of Content s

•When a p art yI ndex inv olv ed wit h a call t hat w as set up w it h t he aid of a gat ek eep er wan t s t o en d t he Icall, nt e rnitetsends w or k inga Te chnologie s Hgaat ndbook , Four th Edit ionek eeper DRQ t o t he ek eep er . Th e gat

m ay also send t he D RQ t o t h e gat ew ay if it wCisco an t sSystems, t o en d tInc. h e call it self . Aft er t h e gat ek eeper r eceiv es t he DRQ f r om t he g at eway , it By r espon ds w it h a D CF t o com p let e t h e call discon nect or a DRJ t o r eject t he gat ew ay 's r equest . Pub lish er: Cisco Press

The D RQ can also b e used t o sen d b illing inf or mat ion abou t t he call being ended t o t h e Pub Dat e: Sep tem ber 1 1, 2 003 gat ek eeper . I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Bandwidth Modification Band wid t h mod ificat ion ( BRQ, BCF, BRJ) allow s a g at eway t o u pdat e or m odify it s b andw idt h usage t o a gat ekeeper . When a call is init ially connect ed t h rou gh a g at ekeeper, t he call is The edit b estr -egar selling all-ofin-t he oneCODEC net w ork ing rIef erence p rov cover age of assuumpdat ed ted o be a ion full of 64t he Kbps, dless used. f ban dw idt h isides limit ed for t he essent ial an d cu t t ingedg e t ech nologies. gat ew ay , it can sen d a BRQ t o t he gat ek eep er t o up dat e it aft er t h e call has b een con nect ed t o t ell t he gat ekeeper, " Hey , I ' m using G. 72 9, so I ' m using only 8 Kbp s for t his call, not 64 Kbps. " The g at ekeeper r espon ds w it h a BCF or BRJ. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Information Request New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP erag e of requ cut t ing t echn e opt n etgat worew k ing age Gat ekCov eeper s can est edge call and st atologies us inf orlikmat ionical f rom aysand u sinst g or t he I RQ m essage. The r eceivin g g at ew ay sh ould r espond w it h an I RR t h at in clud es t he p rop er st at u s inf orm at ion. A by Cisco w or ldw in netunsolicit w or kingedf orast he t erofn et gat ewAut ay hmored ay send t he I Sy RRstmems, essages t o tide he gleader at ek eeper a wI nay id.en t ify ing it self as a " liv e" g at ew ay t o t h e gat ek eeper . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net wn or kin g p r ofessionals un derst anun d im plem t cont y eep int er w ork ing I f t he I RR's eedRespon se field is tpoopulat ed and in an solicit edenI RR t o em t hepor g atarek ernet , t he tgat echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net ek eeper m ay u se t he I ACK or I NACK ack now led gm en t m essag es t o ackn ow led ge t hewI ork RR ing in a indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . posit iv e or negat iv e m anner . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

Resource Availability

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har A g at dweway ar e, pr generat ot ocols, es and an RAI ser vmessage ices inv olv t o ed not . Fu ify ndam a gatent ek eep al t er echofnology it s cu rr infent or mat callion capisacit pryov . Th ided is on a bessage m r oad r ang can ebe of uint sed egrfor al in syfor st em m at s ional and serv p ur poses ices, inorclud t o ing t ell det t heailed gat ek descr eep er ipttion hats,t he revsending iew quest ions t o en gat ewsu ayrecann con cept ot t akcomp e any r eh mor en sion e calls. andThe r et en gatt ion, ek eep and er ad respond dit ional s wr esou it h a rRAC ces f tor o con fu rtfir her m st t he udyst. at e Cov erag and t o steop is sendin also ext g end callsedt on tot hat only gattew o new ay. As n etsoon wor k as ingt he concep congest t s, but ive also st at et ohas oldclear er , legacy ed, t he systew gat emay s, sends pr ovidan in gotaher m or RAI e r, ealist say ing ic pict t haturite can of t he again realhand w or le ld in n et coming w or k ing callenr vir equest onm s. ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Session Initiation Protocol (SIP) SI P ( RFC 25 43) is a p art of t he I ETF Mult ipar t y Mult im ed ia Session Cont r ol ( I ETF- MMSC) pr ot ocol suit e. I t is used f or end- t o- end call signaling and m anag em ent in a pack et net w or k t o pr ov ide v oice, v ideo, and ot h er real- t im e ser v ices t o t w o or m or e endp oint s. SI P is an ASCI I •based pr ot ocol Table of Content t hat oper atses at t h e applicat ion lay er of t he OSI m odel. These key p rop er t ies ar e •seen as adv ant I ndex ages over H. 32 3: I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Ea se of u se , i m p le m ent at i on, a nd t rou ble shoot i ng— Because SI P is ASCI I - b ased, t he m essages ar e pr esen t ed in clear t ex t . The clear - t ex t m essages ar e w rit t en in an easy - t oPub lish er: Cisco Press un derst an d m et hod t h at allow s for quick t r oubleshoot ing and a sm aller m essage size. Pub Dat e: Sep tem ber 1 1, 2 003

Su I SBN: pport 1- 58s705 ex-1ist 19i-2 ng prot ocol s— SI P is an I ETF specif icat ion t hat w or ks seam lessly w it h exist ing pr ot ocols, su ch as Dom ain Nam e Sy st em ( DNS) , Session Descr ipt ion Pr ot ocol Pages: 11 28 ( SDP) , and RTP. D e si gne d t o i nt e gra t e w it h e x ist in g a pp lica t ion s— SI P w as desig ned t o int egr at e w it h dat a app licat ions, such as chat and e- mail. The uD pdat ion eof t henced b est -m selling all- innetcan w ork ing r ef erence p rov idesdless coverofage of e si ed gneedit d for nha obi li t y— Serone v ices follow cust om ers r egar w here essentt hey ial an d cu t t ingedg e t ech nologies. ar e on t he SI P net w or k. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

SIP Messages nov ice t o ex pert .

chapt include cov erag of im liket VoI P and SI P mNew essages arere sASCI I - based. Th ee act ualpor f ort ant mat tt opics in g uses he syn t ax EAP of HTTP v er sion 1. 1, w hich is an I ETF st an dar d for m essag e en coding. Using t his f or mat , you w ill not ice t h at t h e SI P Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age add ress URLs look a lot lik e t he ad dr esses y ou f ind on t he WWW . This is n ot by mist ak e. I t goes back t o ease of d ecodin g, use, and t r oub leshoot in g. I f host nam es are u sed inst ead of I P Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . add resses, DNS ser v er s can be q ueried for n am e resolut ion. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat SI P m essages ar e p laced in t w o m ain gr ou ps—requ est and r espon se. Req uest s are messages enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing sen t f r om a UAC t o a UAS. Resp onses ar e m essag es sent fr om a UAS t o a UAC. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . On SI P n et w or k s, requ est s ar e also called m et hod s. Six main t y pes of m et hods ar e ident if ied in Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, RFC 254 3: and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. I N V I TE— A r eq uest t o set up a n ew SI P session. This session set up met h od is u sed on SI P Reader sw wor ill ks. obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e net har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of intRegist egr al er sysstaem in clud ing det descr s, arev ions REGI STER— SIsPand endpserv oin tices, . A REGI STER m etailed hod is senipt t wion hen SIiew P t erquest m inal t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . r eg ist er s w it h a SI P p rox y serv er t o ident ify it self and it s nu mb er s f or use. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in gack a now m or ledg e r ealist ic of pict of TE. t he Un realor ld n etis w or k ing ed en, vir s inafwt er hich ACK— Final ment anurIeNVI t il wt he ACK r eceiv allonm m etent hods t he pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease I NVI TE ar e considered pr ov isional and par t of t he session set up p rocess. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient OP TIfor ONt hS— r eq uest decisions eir A net w ork s. f or capabilit ies. Th e OPTI ON m et hod is u sed t o q uery a ser v er or anot h er UA for it s session capabilit ies. CAN CEL— Cancels a r equest t h at h as not yet been com plet ed . This is sent if a v oice call is placed ov er SI P, bu t t h e session is t er m inat ed ( t he user han gs u p) b ef or e t he session is answ ered.

BY E— A r eq uest f or session t ear dow n or disconnect . This is sim ilar t o a Discon nect m essage in I SDN. Ex am ple 24 - 1 sh ows a sam ple I NVI TE m et hod. Table 2 4- 10 ex plains t h e m ajor h ead er s.

Exa m pl e 2 4 -1 . SI P I N VI TE M et hod Ou t pu t •

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INVITE sip:[email protected]:5060;user=phone SIP/2.0 By Cisco Systems, Inc.

Via: SIP/2.0/UDP 10.15.1.6:5060 Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 From: ;tag=1E11E574-8FC I SBN: 1- 58 705 -1 19 -2

To: Pages: 11 28 Date: Thu, 12 Dec 2002 20:08:06 GMT Call-ID: [email protected] The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Supported: timer,100rel essent ial an d cu t t ing- edg e t ech nologies. Min-SE: 1800 Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Cisco-Guid: nov ice t o 3533831795-3282768339-2151073359-2667021480 ex pert . User-Agent: Cisco-SIPGateway/IOS-12.x New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP CSeq:Cov 101 INVITE erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by6Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Max-Forwards: I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Timestamp: 947189286 enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Contact:

indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w180 it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Expires: and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Allow-Events: telephone-event Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Content-Type: application/sdp har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int233 egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Content-Length: t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Tab le 2 4 - 1 0 . M a jor SI P I N VI TE He ad er s

•

H e ade r

D e scri pt i on

I NVI TE sip: 20 290 330 00@1 0. 15. 2. 6 : 506 0; user = p hone SI P/ 2. 0

The SI P met h od b ein g sent is an I NVI TE for a v oice call at 10 . 15. 2. 6: 5 060 . The w ell- k now n por t is 506 0, an d t he called nu mb er is 202 903 300 0. Th e user t yp e is a p hone, an d t he v er sion of SI P being used is 2. 0.

Table of Content s

• Via: SI P/ 2. 0I /ndex UD P 10 .1 5. 1. 6: 5 060 I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

From :I SBN: 1- 58 705 -1 19 -2 < sip :Pages: 201 903 300 0@10 . 15. 1. 6> ; t ag= 1E1 1E5 7411 28 8FC

VI A cont ains t he SI P v er sion, t he t r anspor t pr ot ocol, and t he call's or iginat or w it h it s w ell- kn own p ort ( 50 60) . I f t his session w er e t o p ass t hr ou gh pr oxy ser ver s, each ser v er w ould add a VI A header w it h it s ow n ad dr ess. I dent if ies w ho t he call is f r om. Her e t h e SI P URL is ident if ied as nu m b er @I Pad dr ess, b ut host nam es can be u sed in t he sam e for m at , such as joh ndoe@cisco. com .

To: < sip: 2 029 033 000 @10. 15 . 2. 6; user = p hone> I dent if ies w ho t he call is in t en ded for . The The u pdat ed edit ion of t he b est - selling all- in- one net wSI orkPing erence p rovorides cover URLr ef and or iginat u ser t yp age e areofalso essent ial an d cu t t ing- edg e t ech nologies. included. Dat e: Thu, 12 Dec 200 2 20: 0 8: 06 GMT Met hod t im est am p . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Call-nov I D: ice D2A1FE7 3- C3 A u niqu e call id en t ifier t hat is used t o t o ex pert . AB11D 3- 80 39C64F9EF7 84A8 @10. 15 . 1. 6 k eep t r ack of t he call st at e. The r an dom nu like mb erVoI isPfollow ed b y t he @host f or m at . New chapt er s include cov erag e of im por t ant t opics and EAP Min- SE: 1 800 Session t imer . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age User - Agent : Cisco- SI PGat ew ay / I OS- 12 .x I dent if ies ex act ly t he t y pe of ag en t t h at is Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he t ercase, n et . it is a Cisco placing t he call. I n Itnhis gat ew ay r un ning Cisco I OS 1 2. 2. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables CSeq: 101 net wI NVI or kin TE g p r ofessionals t o un derst and an d imCSeq plemst enands t cont f or emcom por ar man y int d sequ er neten w ork ce ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, nuan mbd erdevices . I t cont used ains in t h teoday SI P' m s net et hod w ork t ying pe indu st ry . Lear n how t o incor por at e int er net w or kin g t echn andolog a num ies in erical t o a vLAN/ alueWAN u sed env t o id ir onm en t ify ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , tst his or m age, et hod opt ical in a net u nique w or kman in g, ner. scalabilit Eachy, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er subsequent ence t o t her eq t op uest ics tincr hat em areent essen s t his t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. nu mb er . Max - Forw ar obt ds: ain 6 a g reat er un der st an ding of LAN and The m axnim um ber his Reader s w ill WAN et wum or kning, p ar of t icut im lares ly tt h e malessage m ay binf e for w arion dedist hr t h eon har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent t ech nology or mat prough ov ided net wdet or ailed k. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing descr ipt ion s, rev iew quest ions t oCon entsu dit locat ionalion r esou r ces tfhe or tfu udyUA . actre: con cept comp r eh en sion and r et en t ion, and ad The w here errtmher in atsting Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy < sip : 201 903 300 0@10 . 15. 1. 6: 506 0; user= p hone> can find t he origin at ing UA. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich prEx ofpir essionals es: 18 0 oper at e. Tools and gu id elines f or opt im izing Met hod syst tem im eout per for v alue. m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Con t en t - Ty appnet licat ion/s.sd p I dent if ies t h e int ended cont ent and m ed ia decisions forpe: t h eir w ork t y pe. The " SDP" st an ds f or Session Descr ipt ion Pr ot ocol. I t is used for m edia negot iat ion ( capabilit y ex ch ange) . I t is discussed in t he nex t sect ion . Con t en t - Leng t h: 233

The leng t h of t he cur r en t m essag e.

RFC 254 3 also id en t ifies six classes of m essag es. Each class of messages deals w it h eit her inpr ogr ess or com plet ed act ions. They ident if y dif ferent t y pes of call pr ogr ess messages or session err or s.Table 2 4- 11 list s t h e m ain n um er ical gr oup s of SI P r esp onse m essages and descr ibes t heir u se on t h e net w or k. •

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Tab le 2 4 - 1 1 . SI P Re spon se Code Cl asses

By Cisco Systems, Inc.

Me ssa ge Cl ass

Pub lish er: Cisco Press

D e scri pt i on

10 0 Pub Dat e: Sep tem ber The 1 1, 2 003 1 00 ser ies of m essages specif ies t h at a r eq uest is in pr ogr ess, b ut h as PROVII SBN: SI ONAL not 1- 58 705 -1 19 -2 successfully com plet ed or f ailed y et . Her e ar e som e comm on m essages: Pages: 11 28

10 0— Try ing 18 0— Ringin g

18 1— Call is being f orw ar ded The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of 18edg 2—e Call qu eu ed essent ial an d cu t t ingt echis nologies. 18 3— Session p rog ress Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom 20 0 nov SUCCESS The ice t o ex pert . 2 00 ser ies of m essages specif ies a successf ul com plet ion of a par t icular r eq uest . Ther e is r eally only t he 20 0 OK m essage in t h is class. erag e rof im pornteeds ant t opics VoI EAP locat ion . 30 0 New chapt er s include The SI Pcov session equest t o be like direct edP tand o a new REDI RECTI ON Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age 40 0 CLI ENT An er r or w it h t he client m u st be cor r ect ed. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . ERROR I n50 t ern 0 SERVER et w or k in g TechAn nologies er r or wHand it h t he book ser, ver Four mt ust h Edbe it ion cor, rect is aed. com pr ehensive refer ence t hat enables ERROR net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing 60 0stGLOBAL u serpor h as been eclined w itghtin t heolog neties w orin k,t oand all ot her at t em pt s by indu ry . Lear n how The t o incor at e int erdnet w or kin echn a LAN/ WAN env ir onm ent . FAI LURE t his u ser w ill also f ail. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

Session Reader s w illDescription obt ain a g reat erProtocol un der st an ding

of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a of un int ct egr al w syitst serv ices, in pr clud ing detPr ailed iptm ion s, im rev iewt an quest SIbPr oad w or kr sang in econj ion h em sevserand al est ablished ot ocols. obabdescr ly t he ost por t is tions he tSession o en su reDescr con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy ipt ion Pr ot ocol ( SDP) . SD P is used t o ex ch ange capab ilit ies. You find t h is pr ot.ocol Cov e ect is also ext endged only t o183 newSession n et wor kPring t s, tbut alsoOK t o old er , legacy syn terag ax dir ly f ollowin SI nPotI NVI TE, ogrconcep ess, and h e 200 r espon se for an syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm entes s in I NVI TE. The p ur pose of SDP in t h e SI P net w or k is t h e sam e p ur pose t hat H. 245 serv in wH.hich 3 23 pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease net w or ks. SD P let s m ed ia negot iat ion t ak e place bet w een UAs, including such infor m at ion as pr odu iv it ECs y an and d im RTP pr ov in e for eff iciency, ing m ake e in of t elligent cost aud io ct COD m at ion. help Ex am plet he 24r-eader 2 sh ows t he mor ou t put t he SD, P par- eff amicient et er s f r om decisions for t h eir net w ork s. a SI P I NVI TE m et h od. Table 2 4- 12 d iscusses each of t hese fields in det ail.

Exa m pl e 2 4 -2 . SI P I N VI TE SD P Par a m et er s

v=0 o=CiscoSystemsSIP-GW-UserAgent 762 3453 IN IP4 10.15.1.6 s=SIP Call c=IN IP4 10.15.1.6 •

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m=audio 16952Inc. RTP/AVP 18 100 By Cisco Systems, a=rtpmap:18 G729/8000 Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

a=fmtp:18 annexb=no

I SBN: 1- 58 705 -1 19 -2

Pages: 11 28 X-NSE/8000 a=rtpmap:100

a=fmtp:100 192-194 a=ptime:10 The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Tab le 2 4 - 1 2 . SI P I N VI TE SD P Par a m et er s

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Cov H e ade r erag e of cut t ing edge t echn ologies D e scrilikptei opt on ical n et wor k ing and st or age v = 0 Aut h ored by Cisco Sy st ems, w or ldw Theide v erleader sion ofinSDP net wt hat or king is inf or u se. t he I n t er n et . CiscoSy emsSI P-nologies GW- UserHand Agentbook Or,iginat infor m at ion, in clud ing UA t yrefer pe, net w ort hat k t y pe, I no= t ern et w orst k in g Tech Four tor h Ed it ion , is a com pr ehensive ence 76 2 3 453 I N I P4 10 .1 5. 1. 6 and cont act nam e. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. t s, t echnnam ologies, an d devices used in t oday ' s net w ork ing s= SI P Call Mast er t he t er m s, con cepSession e. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com c= I N plet I P4 e w1 it 0.h15. new 1 .6an d u pdat ed chapt Ier nfsorm on at secur ion it abou y , stt or t hage, e m ed opt iaical t y pe, netas w orink in I Pv4 g, scalabilit or I Pv 6, y, and speed, t h is book is a com plet e an dand u p-ttho-e dcon at enect r ef er ion ence ad dr t oess. t he The t op ics cont nect hat are ion essen add ress t ialist o all net w or kin g p rof essionals, r egar dless oft he ex pert addrise. ess of t he sending UA. t = 0 0 s w ill obt ain a g reat er un der st an Stding ar t an st opand t imWAN es. n et w or k ing, p ar t icu lar ly t h e Reader of dLAN har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology or mat ion is pr ov ided on m = audio 169 52 RTP/ AVP 1 8 100 Media t yp e and t r anspor t por t tinf o be u sed. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t oa=en r tsu pmreap: con 1 8cept G729 comp / 800 r eh 0 en sion and At r ett ren ibut t ion, es as andt hey ad dit app ional ly t or esou the m r ces ed ia f orfield. fu rt her I n t st his udy case, . Cov erag e is also ext end ed n ot only t o includes new n et wor it em k ing s such concep as tthe s, but CODEC also in t o use old er ( G. , legacy 72 9) . a= fm annex syst emt p s,: 18 pr ovid in gb= a no m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease r t pm 00d X00iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient pra= odu ct ivap: it y 1an imNSE/ pr ov80 e eff decisions for t h eir net w ork s. a= fm t p : 100 19 2- 19 4 a= pt im e: 10

SIP Network Devices SI P u ses a client / serv er m odel w hen t r anspor t ing m essages bet w een endp oint s. The t w o ent it ies ident if ied ar e t he u ser ag en t clien t ( UAC) and t he user ag en t ser ver ( UAS) . The UAC is t he client dev ice t hat in it iat es t he SI P r equest . The UAS is t he serv er t hat r espon ds t o t hat SI P r equest . All SI P d ev ices m u st be ab le t o act as bot h a UAC and a UAS. As show n in Figur e 24 - 12, w hen •Bill sen ds a requ Tableest of Content t o Nanscy , Bill is t h e UAC, and Nancy is t h e UAS. Howev er, if Nan cy send s a •r eq uest t o Bill, I ndex t he r oles are r ev er sed . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 2 4 -1 2 . SI P UAC an d U AS Re la t i onshi p

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . User agent s ar e end point devices in t he SI P n et w or k , such as SI P ph ones or gat ew ay s. Mor e t ern et orhker in gUAs Tech nologies book Four h Ed ion ,t siswaitcom ence t hat rI necent ly w , ot h ave b eenHand added, su,ch as tch at it clien h SI pr P ehensive su ppor t orrefer even w ireless enables net wper or kin ofessionals o un and ph ones and songalp rdig it al assist tant s (derst PDAs) . an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear how 2t543 o incor intver er net w or kin g t echnholog ieson in et oora all LAN/ env ir ing onmt ent . Also defin ed inn RFC ar epor SIat P eser s. They t y pically andle of WAN t h e follow asks: Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Regist ion net w or kin g rpat rof essionals, r egar dless of ex pert ise. Redir ectobt ionain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Reader s w ill har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Pr oxy a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . SI P sessions m ay b e set up dir ect ly b et ween UAs or t hr ough int er m ed iaries, such as a SI P Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy r eg ist r ar , r edir ect , or pr oxy ser ver . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease A SI P regist r ar ser v er m anages t h e r eg ist r at ion of en dpoint s and associat ed num ber s in mu ch pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient t he sam e w ay g at ek eep er s h andle t he r eg ist r at ion of H. 323 gat ew ay s. SI P UAs do not h ave t o decisions for t h eir net w ork s. use a SI P r eg ist r ar serv er , bu t a regist r ar ser v er m akes m anag in g t he UAs easier . A SI P redir ect ser v er div er t s SI P session s t o ot h er locat ion s. Applicat ions include call f or w ard in g for busy , no answ er , or m anually r ed irect ed n um ber s. Much lik e t h e dir ect ed call sign alin g used w it h H.3 23 gat ek eeper s, t he SI P redir ect ser v er find s out t he SI P session 's n ew dest in at ion an d r ep or t s it t o t he SI P UA. The SI P UA is t h en r esp onsible for send in g t he SI P I NVI TE message t o

t he new dest inat ion. A SI P pr oxy ser ver is an act iv e int erm ediar y bet w een UAs. I t r eceives inb ound session requ est s and r esp onses, p er f orm s n ame and/ or num ber r esolu t ion, pr ov ides secur it y serv ices, an d act s on behalf of all conn ect ed SI P UAs. The SI P pr oxy ser ver can be eit her st at efu l or st at eless. A st at ef ul SI P pr oxy k eep s det ailed inf orm at ion abou t t h e m essages' t ran sact ion st at us an d, in some cases, call st at e as w ell. Th e • Content s st at eless SI PTable p roxof y sim ply for w ar ds t h e m essages as r eceiv ed and doesn' t w or r y abou t k eepin g •t r ack of w hatI ndex messag es w en t w her e. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

SI P p rox y serv ers By Cisco Systems, Inc.can also per for m session for k in g, in w hich t hey sen d a SI P session requ est t o sev er al locat ion s sim u lt aneously . A SI P pr ox y m ight need t o use t h is feat ur e t o locat e t he pr op er destPub inat ion par t y if a " f ollow - me" ser vice is u sed. Think of t h is as y elling int o a r oom f or lish er: Cisco Press som eon e and t hen w ait in g for t h e pr oper per son t o r esp ond. Pub Dat e: Sep tem ber 1 1, 2 003

I SBN: 58g705 -1 19 -2messages t o m u lt ip le locat ions, t he pr ox y ser v er m ust b e able t o keep Becau se for 1kin sends Pages: 11 28 t r ack of each of t heir st at es. For t his r eason , t o u se for k in g, t h e SI P pr ox y m ust be st at eful in nat u r e. Upon r eceiv in g responses fr om m u lt ip le par t ies, it is up t o t he SI P p rox y t o filt er t h e un necessar y r eplies and for w ar d t he pr op er r esponse t o t he or iginat in g SI P UA. Figur e 24 - 13 illust rat es call f or king an d t h e r et u r n f ilt er ing per for m ed.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r e 2 4 -1 3 . SI P Sessi on For k in g an d Ret ur n Fil t e r in g

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

NO TE

Alt hou gh t he d ef init ions of t h ese SI P ser ver f unct ions ar e d iff er ent , it is comm on t o find SI P serv ers t hat hav e all t hr ee f unct ions.

SIP Call Flows •

Table of Content s

Thr ee basic call flow s ar e d iscussed in t his chap t er . Th e fir st call f low is bet w een t w o SI P UAs. I n • t his case, it isI ndex b et w een t w o SI P g at ew ay s. The t op of Figur e 24 - 14 sh ows t he SI P m et hod I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion t r ansfer b et w een SI P UAs. By Cisco Systems, Inc.

Pub lish er: Cisco Press

Figu r e 2 4 -1 4 . SI P UA-t o-SI P UA Ca ll Flow

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or g Tech nologies t h at Ed tithe iont,op is of a com preehensive refer The f ollow inkginlist d escr ibes t heHand f ive book st eps, Four sh own Figur 24 - 14. Th ese ence st epst hat net or kinsession g p r ofessionals o un renables ep r esent a wbasic set up in t SI P: derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . When origin SI Ped UAchapt init iat t hesecur SI P itsession it sends an net I NVI TEk in requ est sim ilar Com plet e w tithe h new anatding u pdat eres s on y , st or ,age, opt ical w or g, scalabilit y, t o t he one discussed earlier. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. The t er m inat ing SI P UA r esp onds w it h a 100 Tr y in g message t o not ify t he r equest er t hat t he Reader s wmessage ill obt ainhas a g been reat err eceived. un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Aft er t hee tof er int min at al ingsySI UA locatserv es t he r esou rceing an ddet f inds t o beipt avion ailab le, iew t he quest ions a b r oad r ang egr stPem s and ices, in clud ailedit descr s, rev t erre min atcept in g SI P UAr eh sen a 180 ing m essage o aler t trhe or iginat UA. t o en su con comp ends sion and Ring r et en t ion, and adtdit ional esou r ces f in or gfuSI rtP her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy When he called p art t h eurph t erw mor inat a 20ent 0 OK syst em s, pr tovid in g a m or ey ransw ealister icspict e one, of t het he realld ing n et wSIorPkUA ing sends en vir onm s inmwessage hich t o t he or iginat in g SI P UA. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient This m essag e m ust b e answ er ed wit h an ACK message. At t his t im e, t he SI P session is decisions for t h eir net w ork s. act ive. The b ot t om of Figur e 24 - 14 sh ows t he call t ear dow n or discon nect pr ocedur e. Discon nect in g t he call is sim p le, b ecause t h e par t y t h at d ecides t o hang up sends a BYE m essage. This m essag e is r espon ded t o w it h a 2 00 OK m essag e.

The second call flow is b et w een t wo SI P UAs, but a SI P pr oxy ser ver act s as an in t er m ediary bet w een t h em , as sh own in Figur e 24 - 15. I n pur e p rox y m ode, t he only t h ing t hat is diff erent is t hat t he SI P pr ox y ser v er in t er cept s an d " p r oxies" t he messages bet w een SI P UAs.

Figu r e 2 4 -1 5 . SI P UA-t o-SI P UA Ca ll Flow w it h SI P Pr oxy Ser v e r •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all When SIgPppr oxy is in volvred w it h a SI session , it h as t he opt ion of t ur ning on a f eat ur e called net w orakin rof essionals, egar dless ofPex pert ise. r ecor d rou t e. Th e r ecor d r ou t e header allow s t he p r oxy ser ver t o st ay in t h e signaling pat h f or t he session long hat er session actding ive. of I f tLAN he call oug h kming, or e pt haran onlar e ly pr ox Reader s w illas obt ain as a gtreat un deris st an andgoes WANt hr n et w or t icu t h ey, each subsequent y canand alsoser b ev ices add ed o ted he. rFu ecor d r out . Th at inf w ay , a backw raceable har dw ar e, prprotox ocols, invtolv ndam entealh tead echer nology or mat ion is ar prdovtided on pat t o trhe session' or al igin ist s. a b rhoad ang e of intsegr syex st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . The erag last ecall flow ext invend olv es SI P rned ectk serv er . Witths,t his , t he essage Cov is also ed t nhe otuse onlyoft oa new etirwor ing concep but call alsof low t o old er ,mlegacy exchan ges ar e slig ht ly dif fer en t . Figur e 24 16 sh ows t he call f low bet w een t w o SI P UAs ar e syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s int hwathich using a SI P redir ect ser v er. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figu r e 2 4 -1 6 . SI P UA-t o-SI P UA Ca ll Flow w it h SI P Redi r ect Ser v e r

•

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . The r edir ect ser v er is used in m uch t he sam e w ay a g at ek eep er is w it h d ir ect ed call signaling . The r edir ser er v ers include is used only t o ident if y por t het ant locat ion oflike t heVoI t erP mand inat ing Newect chapt cov erag e of im t opics EAPUA. Aft er t h at h as been est ablish ed t hr ou gh a 30 0- series m ult iple- choice message, t he or igin at ing UA is respon sible f or com mu Cov nicat erag ineg of dircut ecttly ingw edge it h t het echn t er mologies in at inglik UA. e opt Allical ot her n etcom wor kming unicat andion, st orinclud age in g session disconnect , is han dled b et w een t he t w o UAs. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Connecting VoIP Networks with the SS7 Network VoI P is u sed for m an y applicat ions. I n a lot of in st ances, conn ect iv it y int o t he legacy ser v ice pr ov ider net w or k is r eq uired t o com m un icat e w it h non - VoI P net w or ks. Th e ser v ice p rov ider SS7 net w or k is an int ern at ional n et wor k t h at r eaches ev en t he m ost r em ot e spot s on t he planet . The •SS7 net w ork Table of Content ' s cover age is sin alm ost ever y par t of ev er y coun t r y. •

I ndex

IMillions nt e rn et wof or km ing Te chnologie s H a ndbook Four th ar Edit iles of lan d- line ph one, cable e ion deploy ed t hr ough out t he w or ld, an d conn ect ing int o tBy hat inf rast r uct u re g ives user s of VoI P net w or ks man y possibilit ies. For v oice p rov ider s, t he Cisco Systems, Inc. pr iv at e I P net w or k can ser ve as a cost - saving long - haul t r anspor t m echanism . For I SPs, t he dial t r aff ic can b e off loaded f r om t he ser vice pr ov ider net w or k befor e it t ies up valu able r esour ces for Pub lish er: Cisco Press ext end ed p er iods of t im e. Mer ging t he dat a and voice net w or ks cr eat es an in t r icat e com bin at ion Pub Dat e: Sep tem ber 1 1, 2 003 of ser v ice possibilit ies, su ch as t w o- st ag e dial ( p hone car ds) , r esou r ce p ool m anag em ent ( RPM) , I SBN: 705 -1 19m -2essag e client s. and even SI1-P-58based Pages: 11 28

Alt hou gh H.3 23 and SI P ar e bot h em er g in g as popu lar m et h ods f or deploy ing voice serv ices, t h e fact r em ains t hat t he ser v ice pr ovid er n et wor k s t h rou ghou t t h e w orld hav e b een deploy ed for sev er al decades. Wit h t hat in m ind, H.3 23 and SI P m ight help pr ovid e increasingly ad van ced ser v ices t o end user s, bu t t hey w ill lik ely com plem en t in st ead of r ep lace it for t he near f ut u re. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary Voice over I P ( VoI P) has em erg ed in r ecent year s as a hot t opic am ong ent r ep reneur s, ent er pr ise net w or ker s, and m ult im illion- d ollar ser v ice p rov ider s. As w it h an yt hing in t he ind ust ry , it has t o do w it h m on ey . Th e abilit y t o t ran sp ort v oice ov er a p r iv at e I P in fr ast r uct ur e allow s com p anies •t o sav e on cost Table of Content s ly legacy TDMbased conn ect ions and per- m inu t e char ges f or long- d ist an ce calls. •I n ef fect , t hese I ndex com panies become t heir ow n lon g- dist ance p rov ider s. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Wit hin tSystems, he realmInc. of VoI P ar e t w o com p et in g y et v ery sim ilar t ech nologies—H. 3 23 and SI P. To By Cisco m any , VoI P au t om at ically m eans H. 323 . The I TU d ev eloped t h e H. 323 pr ot ocol suit e as a m ult im ed ia suit e of pr ot ocols f or pack et - b ased net w or ks. Alt h ough t h e vid eo and dat a por t ions Pub lish er: Cisco Press of t his p r ot ocol su it e hav e not been u sed t o t he sam e dept h as t h e v oice aspect s, t hey do exist . Pub Dat e: Sep tem ber 1 1, 2 003 Voice t r anspor t h as been w idely deploy ed t h r oughou t t he w or ld . Ev er y day , ser v ice pr ovider s pu t I SBN: 158 t705 -1t19 m or e voice por s in o -2 t h eir H. 3 23 net w ork s. Pages: 11 28

H. 323 specif ies a nu m ber of diff erent dev ices f or use un der t he p r ot ocol um br ella. H. 3 23 t er min als are end point dev ices t hat int er act dir ect ly wit h t h e H.3 23 net w or k, su ch as I P phon es or H. 32 3- enabled sof t w ar e packag es on PCs. H.3 23 gat ek eeper s and dir ect ory gat ekeepers are opt ion al dev ices t hat allow y ou t o scale t he H. 32 3 n et wor k . Gat ek eep er s k eep t r ack of w hich gat ay s ed canedit serion viceofwthich ber s, and dirone ect ornet y gwat eking eep rerefserence k eep t p r ack of w cover her e tage he of Theew u pdat he b num est - selling all- inork rov ides dif fer en t gat ek eep er s ar e locat ed ( as w ell as wh ich gat ew ay s t hey cont ain ) . essent ial an d cu t t ing- edg e t ech nologies. H. 323 gat ew ay s ar e dev ices t h at connect t he H. 323 n et w or k t o a n on- H. 323 net w or k , such as a gat ewCon ay tcise h at ov conn e olog H.3 23 w ort ial k t ot oa nser v icek ing p rovprider 's TD Met wor er vect iews saofprtivat echn ies net essen et wor ofession alsbased at all nlev els, kf .rom Mu lt ipnov oinice t cont rol unit s ar e d ev ices t hat con t rol H.3 23 confer ences w it h in an H. 323 n et w or k . t o ex pert . Man y devices incorp or at e some sor t of MCU f unct ionalit y w it hin t heir code, and MCUs are becom in g chapt less and comcov m on in eact e deploy s. like VoI P and EAP New er s less include erag ofivim por t antment t opics H. 323Cov is aerag su iteeofofcut pr ot ocols t hat w ork t oget her o prical ovid e wor r eliable oicestcall set up , t eard ow n, t ing edge t echn ologies lik e topt n et k ing vand or age and m anag em ent . Th e H. 323 specif icat ion is u sed as an um br ella sp ecif icat ion t hat act s as t h e " glu e"Aut forh ored all t he byotCisco h er sp Sy ecificat st ems,ions w orin ldw clud ideedleader . H. 225in isnet u sed w or king for call f orset t heupI nand t er ntet ear . dow n. I t is loosely b ased on I SD N Q. 93 1 sign alin g, an d it has m any of t he sam e char act er ist ics. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables H. 245 is net u sed w orfor kincapab g p r ofessionals ilit y ex chang t o e. un The derstcapabilit and an dies imex plem chan enged t cont ar em e itpor em ar s such y int er asnet audio w ork ing t echnologies. CODECs. An otMast her adv er tant he ag t eremof s, tcon he VoI cep P t s,net t echn w orkologies, is t he ab anilit d devices y t o useused t h e sam in t oday e am'ou s net nt w ofork ing indudw ban st ry idt. hLear t o tnran how sp or t ot incor m or epor calls at euint sinerg net CODECs. w or kin gCOD t echn ECsolog com ies prin ess t o taheLAN/ v oice WAN st r eam env irtonm o varent y ing . Com plet degr ees eand w it tho new v ar yin angd quualit pdatyed . G. chapt 72 9 er can s on t r anspor secur itt yeigh , st or t tage, im esopt m ore ical calls net w in or kainsingle g, scalabilit D S0 t han y, and a t rad speed, it ion alt hserv is book ice prisovid a com er net pletweork an.dAlso u p- tfounct d ationin e r efgerw ence it h H. t o245 t he ar t op e ics RTPt hat andare RTCP. essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. RTP is used specifically t o m anag e t he v oice pat hs bet w een en dpoin t s. RTP p r ovides t h e r ealtReader im e sers vwices ill obt t h at ainaraegrreat equir ered unt der o t rst anspor an ding t voice of LAN calls andover WAN ann et I Pwnet or kwing, or k .pRTCP ar t icu pr larov ly ides the har dw ar e,onprtot feedback h eocols, RTP st and r eam sers.v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions SI t echn ology hatsion w asand cr eat the I ETF. I t ional is in clud ed r uces nder MMSC. t o Penissuarenew conercept comp r ehten r eted en tby ion, and ad dit r esou f orI ETFfu rt her st udyRFC . 25 43 w as t healso in itext ial end ver sion of tonly h e SI pr ot ocol. SIkPing w as d esigned t o also help talleviat som e of t he Cov erag e is ed n ot t oP new n et wor concep t s, but o old er e , legacy shor t comin exp er a ienced it h H.ic 323 . SI dev elopwed asnaettw r ue ult en im vir edia p rot hat syst em s, prgs ovid in g m or e wr ealist pict ur P ew ofas t he realor ld or kming onm entocol s in tw hich w seam lessly est ablished, prelines ot ocols, asizing DNSsyst an dem SDper P. for m ance w ill incr ease pror ofks essionals oper w atite.h Tools and gu id f orsuch opt im pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient SI P is an ASCI - based decisions for t hI eir net wclearork s. t ex t st r uct u re t hat uses t he HTTP 1 . 1 encodin g schem e. This allow s for easy d ecoding an d t rou bleshoot in g of SI P net w ork s. SI P m essag es w er e designed in a client / ser ver m odel u sin g UACs and UASs. Ev er y device in t he SI P net w ork mu st be capab le of fu nct ioning in eit h er mod e. SI P UAs ar e dev ices t hat ar e t y pically associat ed w it h being an end - user dev ice, such as a SI P ph one. How ev er , t his can also include SI P gat ew ays. SI P UAs can set up SI P sessions d ir ect ly

w it h each ot her or t hr ough a SI P pr ox y ser v er . SI P p rox y serv ers can per for m t hr ee d ist in ct fu nct ions. They can be u sed as a r egist r ar ser v er , pr ox y ser v er , or redir ect ser v er, or a com binat ion of all t h ree. SI P p rox y serv ers pr ovid e cen t r alized m anagem en t of UAs, call rou t e det er min at ion, secu rit y , t r anslat ion, and SI P net w or k ser v ices. For sev eral year s now , I P net w or ks an d ser vice pr ov ider net w or ks hav e been m erg ing. This • of Content s int egr at ion isTable inevit ab le due t o t he rising dem and for cov erag e and ser v ices an d t he qu est t o •low er cost s. SS7 I ndexint er con nect solut ions conn ect next - generat ion I P n et w or k s t o legacy serv ice Ipr ntov e rnider et w or k ing Teks. chnologie s H a ndbook , Four tht Edit ion net w or Alt h ough VoI P doesn' ap pear t o b e going an yw her e, it 's not lik ely t o ov Cisco By er t akSystems, e t h e serInc. v ice p rov ider inf rast r uct u re an yt im e soon. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What is an H. 323 gat ek eep er ?

2:

I ndexis t h e pur pose of SDP? What

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Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

: WhatInc. is By Cisco3Systems, 4:

t h e main r eason t h at com panies deploy H. 32 3 an d/ or SI P net w ork s?

What pr ot ocol ar e t h e m essages in H. 2 25 based on —Q. 921 , Q. 93 1, Q. 9 32, or Q. 70 3?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I5SBN: 1- 58 705 -1 19 -2 : Which device Pages: CODEC 11 28

6:

is r esp onsible for pr ocessin g voice st r eam s an d p er f orm ing com plex algor it hm s?

What m essage m u st follow a 20 0 OK m essage w h en it is receiv ed?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information H.323 •

Table of Content s

•

I ndex

•I nt w ewrnwet.cisco. com pcgi- bins/HSupp ort /, br owthse/ psp_ w or k ing Te /chnologie a ndbook Four Edit ion view . pl?p= I nt er net w ork ing : H323& s= I m p lem ent at io By Cisco Systems, Inc.

• w w w .cisco. com / en/ US/ t ech/ t k6 52/ t k 90 / t ech nologies_ t ech _not e09 186 a008 010 fed1. sht m l# int r o Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

• w w w .cisco. com / en/ US/ pr oduct s/ sw / iossw r el/ ps18 33/ pr oduct s_f eat u re_g uide_chap t er 0 9186 a008 0 I SBN: 1- 58 705 -1 19 -2

Pages: 11 28

• w w w .cisco. com / en/ US/ t ech/ t k6 52/ t k 69 8/ t echnologies_t ech_n ot e0 918 6a00 800 94ae2. sht m l# t opic2 • w w w .cisco. com / en/ US/ pr oduct s/ hw / r out er s/ ps221 / pr oduct s_conf igur at ion_ guide_ch apt er0 918 6a00 The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. • w w w .cisco. com / en/ US/ t ech/ t k6 52/ t k 69 8/ t echnologies_w hit e_p aper0 918 6a00 800a8 993 . sh t m l# sou

SIP

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

t ing edge • w w wCov .ieterag f .or g/e rfofc/cut rf c2543 . t xt t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . • w w w .cisco. com / en/ US/ pr oduct s/ sw / voicesw / p s2 157 / pr oduct s_ad minist r at ion_ guide_chap t er 0 918 I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing SS7 Interconnect for por Voice indu st ry . Lear n how t o incor at e intGateways er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all •net w wwwor.cisco. / en/ US/ t ech/ t k6dless 52/ t kof 65ex 3/pert t echnologies_w hit e_p aper0 918 6a00 8011 375 8. sht m l kin g pcom rof essionals, r egar ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Glossary Terms cal l le g. A log ical con nect ion bet w een t w o H.3 23 t erm inals. Each endp oin t alon g t h e call set u p p at h Table of ifContent s has t w o ident iab le call legs—in and out .

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

CLEC.

Pub Com lish er:pet Cisco it ivPress e Local

Exchan ge Car r ier . A st art up ser v ice p rov ider t h at com pet es w it h t h e voice, dat a, and ser v ice cust om ers. Most w ere cr eat ed af t er t he Telecom I SBN: 1- 58m 705 unicat -1 19 -2ions Act of 1 996 inst illed com pet it ion in a classically m onopoly - dom inat ed indu st11 ry28 . Pages:

Pubest Datablish e: Sep tem 1 1, 2 003 ed ber RBOCs for

COD EC. The u pdat edit ion decom of t he pr b est - selling all- in-/one net ingprr ef erence p rov of Comed pr ession/ ession ( or coder decod erw) .ork Com esses voice stides r eamcover s t o vage ary ing essentdegr ial an d cu t t ingedg e t ech nologies. ees t o p rov ide m or e- ef ficien t u se of b andw idt h in an H. 323 net w or k. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom H . 2 2 5nov . ice t o ex pert . New chapt s include cov erag im por ant .t opics like call VoI P and An I TU sp er ecificat ion based oneI of SDN's Q.t 931 Pr ovides set up EAP and t ear dow n messag ing for H.3 23 calls b et ween en dpoint s. Work s w it h H. 245 , RTP, an d RTCP for com plet e call Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age set up. Uses a single RLC for call t ear dow n. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat H . 2 4 5 . net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing enables t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing An I TU sp ecificat ion used f or capabilit y exchan ge b et w een end point s dur ing H. 323 call indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . set up. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. H.323 . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw A arpe,r ot procol ot ocols, ser . Fu ent alt rt ansp ech nology or mat is prnet ov ided su it eand creat edv ices by t hinv e olv I TUedfor mndam ult im edia ort in inf a pack et ion - based w or k on . a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Used w idely for VoI P t ran sp ort . The H. 32 3 sp ecificat ion descr ibes t he in t er act ion bet w een t o en su con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . allreinclud ed pr ot ocols. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr iv it d im help ing t he r eader m ake mor e in t elligent , cost - eff icient H .odu 3 2 3ctdi reyctan ory gaprt ov e keeeeff peiciency, r. decisions for t h eir net w ork s. Let s y ou scale an H. 323 n et w or k t o a level ab ove gat ekeeper . The d ir ect ory gat ekeeper k eeps t rack of t h e dif ferent gat ek eep er s and w hich num b er s shou ld b e rou t ed t o t hem .

H . 3 2 3 ga t e k ee pe r. A d ev ice t hat allows you t o scale t h e H.3 23 net w or k by m aint ain in g list s of H. 32 3 gat ew ay s and w hich num ber s t hose g at ew ay s can ser v e.

H . 3 2 3 ga t e w a y . •

Table of Content s

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I ndex A d ev ice t hat connect s an H.3 23 net w or k t o a non - H.3 23 net w or k, su ch as t h e PSTN.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

H . 3 2 3 t e rm in al .

Pub lish er: Cisco Press PubADat e: Sep ber int 1 1,er 2 003 d ev icetem t hat act s

dir ect ly w it h t he H. 32 3 n et wor k , such as an I P ph one.

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

I LEC. I ncum bent Local Exchan ge Car r ier . An est ablish ed n at ional serv ice pr ovid er in t h e U. S. Also called an RBOC. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. MCU . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov t o ex pert r. ol Unit . Let s you conf er ence t hr ee or m or e H. 323 d ev ices. Mu ice lt ip oin t Cont New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age OSI m ode l. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Op en Sy st em s I nt er connect ion m odel. Th e I SO cr eat ed t he OSI m odel in 198 4 t o help e gequip int er operat ion, bFour et w teen s baycom pr ov ing a sevener comm I n t ern facilit et w orat k in Techment nologies Hand book h Edvitendor ion , is pridehensive referlay ence t hat on fr am ew ork for all v endor s t o dev elop against . enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, RBOC. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w orRegional kin g p rofBell essionals, egar dless of .ex pert ise.ion al ph one com panies t hat w ere cr eat ed af t er Oper atring Com pany Th e r eg t he br eak up of AT& T at t he end of 19 83. Bell Sou t h, Sou t hw est Bell, and Bell At lant ic ar e Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e all RBOCs. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy RTCP. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e.r ol Tools id elines optoint im izing pery for w ill incrion ease Real- Tim e Cont Pr ot and ocol.gu Repor t s t of or endp s on syst t h e em qualit of m d ance at a dist r ibut pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient pr ov ided on t h e lin k. decisions for t h eir net w ork s.

RTP . Real- Tim e Prot ocol. Tr ansp ort s real- t im e st ream s of v oice in an I P env iron m en t f or bot h

un icast and mu lt icast t raf fic. RTP st r eam s ar e u nidir ect ional, so a call bet w een t w o endp oin t s has t w o RTP st ream s.

SI P . Session I n it iat ion Pr ot ocol. Par t of t he I ETF- MMSC pr ot ocol suit e. Used for en d- t o- end call Table of Content s signaling and m anag em ent in a packet net w or k t o p rov ide v oice, video, an d ot her r ealI ndex t im e ser v ices t o t w o or mor e end point s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

SI PPub Mlish e t er: hod. Cisco

Press

Pub Dat e: Sep tem ber 1 1, 2 003

SI P r equest m essag es. I SBN: 1- 58 705 -1 19 -2

Pages: 11 28

SS7 . Signaling Sy st em 7. Th e sig naling sy st em used in t er n at ion ally t o p rov ide sign alin g set up, t ear dow n, link man agement , and ser v ice cap acit y t o subscr ib er s. ( Kn own as C7 The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of int er nat ionally .) essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom TD M.nov ice t o ex pert . Tim eD iv ision Mult iplexing . The ocess of div id inglike t imVoI e int p or EAP t ion s called t im eslot s. New chapt er s include cov erag e ofp rim por t ant t opics Poand Each t im eslot is a m om en t in t im e and is allot t ed a sp ecif ic ch annel t o t r ansm it dat a on t he neterag w or k. Forcut ext am cirologies cu it haslik24 t imeslot Timeslot # 1 tst r ansm Cov e of ing ple, edgea tT1 echn e opt ical ns. et wor k ing and or ageit s, and t hen 2, and t h en 3, and so on. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat U AC. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Ag en t Client . Origpor in at r eqeruest in kin t h eg SI P net w ories k. in t o a LAN/ WAN env ir onm ent . indu st User ry . Lear n how t o incor ates e int net sw or t echn olog Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. U AS. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Agoten t Ser ver ev ice hatedr espon ds t oent t he equest f r om hemat UAC. har dw User ar e, pr ocols, and. The ser v dices invtolv . Fu ndam al rt ech nology inftor ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy V AD . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper e. Tools and gu idinelines f ornet opt syst ance twuillseincr Voice Act iv it at y Det ect ion. Used H. 3 23 w im orkizing s t o pr ovem ide per m orfor em ef ficien of ease net w ork pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient r esour ces. Dur ing a t yp ical VoI P call, ev en silen ce is t ran sp ort ed acr oss t he I P n et w or k . decisions for VAD t h eirisnet w ork s. When used , silence is d et ect ed an d is not t ran sm it t ed.

V oI P .

Voice over I nt er net Prot ocol. A t er m coined t o d escr ibe t he t ran spor t of v oice over an I P inf rast r uct ur e. Alt hou gh m ost people associat e t he H. 32 3 p rot ocol su it e ex clusively w it h VoI P, ot her st an dar ds m ay be used , such as SI P.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 25. Dynamic Packet Transport/Spatial Reuse Protocol • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Descr ibe t he back gr ound of DPT/ SRP.

By Cisco Systems, Inc.

Ex plain t he D PT/ SRP ar chit ect ur e. Pub lish er: Cisco Press

Under and band th Pub Dat e: st Sep tem ber 1 1,wid 2 003

reuse.

I SBN: 1- 58 705 -1 19 -2

Descr ibe t he DPT/ SRP pack et f orm at . Pages: 11 28

This chap t er int r oduces Dy nam ic Pack et Tr anspor t ( D PT) and Sp at ial Reuse Pr ot ocol ( SRP) . I t exam ines t h e DPT archit ect ur e and SRP' s f eat u res, includ in g b andw idt h op t imizat ion , pack et pr ior it y, t he f airn ess algor it hm , an d t opology d iscov er y . The packet for m at s of bot h cont r ol an d dat a planes ar e ex plained. Finally, t his chapt er look s at how DPT sup por t s m ult icast t r aff ic. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Cisco elop echenology , based on t h e MAC- lay er SRP, t o pr ov ide a band wid t h- eff icient essentdev ial an d ed cu tDPT t ing- tedg t ech nologies. r ing t ech nology op t im ized for p ack et t r an sp ort . I t pr ov ides scalab ilit y of n odes, plug- an d- p lay oper at ion, sup por t f or pr ior it y t r aff ic, fair ban dw idt h usage t o all n odes on t he r ing, and fast er v iew s s. of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom r ecov Con ery cise f r omov r ing fault nov ice t o ex pert . The SRP p rot ocol is b ein g consider ed as p ar t of t h e st andar dizat ion for I EEE 802 . 17 Resilient New chapt er is s include covep erag e of .im t ant t opics slike VoI EAP Packet Ring. SRP m edia- ind en dent Dpor PT im plement SRP ovPerand f ib er in SONET/ SDH f r amin g; hence, DPT can b e deploy ed t r anspar ent ly ov er SONET/ SDH, WDM, or dar k fib er in fr ast r uct ur e. Cov erag t ing ologies opt ical sn et wort koing and st or Sup por t of b otehofmcut u lt im odedge e andt echn sin glemod elik fibe er allow DPT deployed w age it hin t he POP and also as MAN and WAN link s, t y pically at OC- 12c/ STM- 4 c ( 62 2 Mbps) sp eeds and abov e. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DPT Architecture DPT con nect s nodes ( also called st at ions) t o t w o count er rot at ing fiber r ings. Th ese ar e called t h e inner an d out er r in gs. Bot h r ings ar e p art of t he sam e I P su bnet . Unlik e ot her du al- rin g t echnologies, such as FD DI , t her e is no idle or st and by r ing. Bot h r ing s t r ansm it pack et s •concur r en t ly.Table of Content s •

I ndex

I nt e rne et 25 w or- k1ing Te chnologie s Hcon a ndbook , Four Edit ion Figur illust r at es t he nect ion ofthDPT nodes v ia t h e t w o r ing s. By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Figu r e 2 5 -1 . D PT Con ne ct i vi t y

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. As show n in Figur e 25 - 1, each n ode sends t he dat a pack et s in on e dir ect ion ( dow n st r eam ) on Reader a rgol reat er et unsder anopp dingosit of eLAN and n et w or k ing, p arott icu ly g. t hTh e e one r ings w anilld obt t h eain cont pack in st t he dir ect ionWAN ( upst r eam) on t he herlarr in har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided onof cont r ol p ack et s pr ov ide f eat u res, such as t opology discov ery an d failur e r ecov ery . Th e decision a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions w hich direct ion t o send packet s t o r each anot h er node is mad e by t h e Add ress Resolu t ion tPr o ot enocol su re( ARP) con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . pr ocess. An ARP p acket is sent on one r ing, and t he t ar g et r espon ds v ia t h e Cov is also n ot ed only new et wor k ing concep s, but The also ARP t o old , legacy shorerag t est -ehop pat hext asend deted er min byt ot he t opnolog y discover y pr tocess. orer iginat or uses t he syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in w hich r ing t hat t he ARP r esp onse w as r eceived on t o sen d fut ur e packet s t o t h at t ar get node. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr imof pr ov e eff iciency, ingmt en het ,r eader m ake mor in t elligent , cost Asodu parct t iv ofittyheangdoal plug - and - play help deploy add it ion al nod ese can be added t o -teff h eicient r in g at decisions for t h eir net w ork s. any st ag e w it hout r econf igur ing any of t he exist ing nod es or m anagem en t sy st em in t erv ent ion. The r ing h eals ( w r aps) arou nd t he d isconn ect ion w hile t he n ew node is added. This r esilien cy is discussed lat er in t h is chapt er .

SRP Bandwidth Optimization Unlike ot her pack et r in g t echn ologies, such as Tok en Rin g, SRP has no t ok en cir culat ing t he ring , so m ult iple st at ion s can t r ansm it on t h e r in gs at t he sam e t im e. SRP uses dest in at ion st r ippin g, w hich occur s w hen t he receiv ing st at ion r em oves t h e pack et fr om t he r ing. There is n o n eed t o •w ait f or t he tTable of Content r ansmit t in g stsat ion t o receiv e t h e packet aft er it has cir cu lat ed t he en t ire r ing an d •r em ov ed it frIom ndext h e r ing. Hence, gr eat er ban dw idt h ut ilizat ion can be ach iev ed . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Figur e 25 - 2 sh ows By Cisco Systems, Inc. mu lt iple pack et s cir culat ing t he r ing s sim u lt aneously . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Figu r e 2 5 -2 . SRP B an dw idt h Re use

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Isyst n Figur e 25 - 2, SRP ovorides t he micechanism o ld send t oorNode At onm t h e same em s, pr ovid in g aprm e r ealist pict ur e off or t heNode real-1w tor n et w k ing 3. en vir ent s int ime, w hich Node 2 sends oper t o Node b ecause t h eidpacket ar opt e on if fer en t segm entfor s of t h e out er incr r ing. pr of essionals at e. 4Tools and gu elines sf or imdizing syst em per m ance w ill ease Meanw 5 pr also a packhelp et t oing Node via t he in nermor r ineg.inIttelligent is possib le for pr odu cthile, iv it y Node an d im ov esends eff iciency, t he r4eader m ake , cost - effeach icientnode tdecisions o hav e fufor ll access t o twhork e ms.ed ium 's t ran sm ission speed . t h eir net Not e t h at m ult icast p ack et s ar e sour ce- st r ipped rat her t han dest inat ion- st r ipped t o en su re t hat all nod es receiv e t h e m ult icast packet . I f m ult icast p ack et s w ere d est inat ion - st rip ped, t h e fir st m ult icast - en abled n ode r eceivin g t h e pack et w ould st rip it f r om t he ring . I nst ead, each n ode m akes a copy of t he mu lt icast packet for it s ow n use an d f or w ard s t he or igin al pack et t o t he nex t

nod e. When t he m ult icast pack et ar r iv es back at t he or iginat in g node, it is st r ipp ed f rom t he r ing. When a n ode r eceiv es an incom ing dat a pack et , it m ay do one of t h e follow ing: St r ip t he p ack e t f rom t h e ri ng— The pack et circulat ed t he r ing an d w as r em oved by t h e sen ding nod e ( for ex am ple, a m ult icast p ack et r et ur ned t o t h e or iginat or ) . • •

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Re cei veI ndex a nd st ri p t he pa ck et — The pack et is dest ined for t h is node' s Lay er 3 addr ess.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Re cei ve a nd f orw ar d t he pa ck et — I t is a m u lt icast p ack et an d mu st be p assed on.

By Cisco Systems, Inc.

Forw ar d t he pa ck et on t he ri ng— The pack et is not add ressed f or t his n ode. Pub lish er: Cisco Press Pub WDat rae:p Sep t hetempa berck 1 1, et2 003 ba ck

ont o t he ot he r ri ng— A r ing fau lt or ot h er discon nect ion has occu r red, and-1 19 rin-2g w r ap is in ef fect . I SBN: 1- 58 705 Pages: 11 28

P ass- t hr ough t he pack e t on t he r in g— This nod e' s cont r ol p lan e is not in op er at ion .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SRP Packet Priority SRP pr ovid es four t ran sm ission q ueues—t w o queues f or t r aff ic sour ced ( or t r ansm it t ed) by a nod e and t w o q ueues for t r affic t ran sit in g t h e r ing t hr oug h t h at n ode. The t wo t r ansm it qu eu es ar e desig nat ed as high - or low - p rior it y t r ansm ission queues. Sim ilar ly , for t r ansit t r aff ic, t he •nod e also has Table of Content a high - an d slow - pr ior it y qu eu e for each rin g. The I P Pr ecedence and SRP Pr ior it y •fields sup por It ndex eigh t pr ior it y lev els, w hich ar e m app ed t o eit h er t he hig h- or low- pr ior it y q ueues. IThis nt e rnm etapp w or king ing can Te chnologie H a ndbook , Four th Edit ion b e cu sts omized. By Cisco Systems, Inc.

Packet s ar e t r an sm it t ed fr om t h e fou r queues in t he follow in g ord er : Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

1 . Highr ior it y-1t r19 ansit packet s I SBN:p158 705 -2 Pages: 11 28

2 . High- p r ior it y t r ansm it p ack et s 3 . Low - p rior it y t r ansm it p ack et s 4 . Low - p rior it y t r ansit p acket s The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Thr eshial olds s ar e used t o ensur e t hat t r ansit t raf fic is n ot d rop ped b y essent anand d cufteedb t ing- ack edg emechanism t ech nologies. t he t ran smit t in g of n ew t r aff ic by a node. This is defined in t h e SRP Fair ness Algor it hm . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SRP Fairness Algorithm The SRPFair ness Algor it hm ( SRP- f a) ensu res t h at n o one n ode can m onopolize t h e rin g an d pr event ot her n odes fr om accessing t heir f air sh ar e of t he b andw idt h w hile at t he sam e t im e allow in g a nod e t o u se any f ree ban dw idt h . •

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•This f lex ibilit y I ndex is achieved via an alg orit h m execut ing on each n ode. When a n ode exp er iences Icongest nt e rn et wion, or k ing a ndbookban , Four thidt Edit it rTe epchnologie ort s it s st rHansmit dw h ion usage v ia cont rol packet s t o it s up st ream n eigh bor . The u pst r eam node u ses t his v alu e in a feedback loop t o adju st ( t h rot t le) it s t r ansm ission r at e on By Cisco Systems, Inc. t he rin g. This n ode m ay , in t ur n, ad vise it s u pst r eam neig hbor . Th e det ails of t he alg orit h m' s oper at ion are com plex. Refer t o t he " For Mor e I nf orm at ion" sect ion at t he en d of t his chapt er t o Pub lish er: Cisco Press learn m or e. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

NO TE SRP- f a op er at es only on low - pr ior it y t r aff ic. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DPT Resiliency DPT rin gs use I nt elligent Prot ect ion Sw it ch in g ( I PS) t o p r ovide fast r ing r ecov ery fr om nod e or fib er fault s. I PS can det ect Layer 1 fau lt s and self - heal w it hin 50 m s w it hou t causing Lay er 3 r econv er gence. Ring r ecov er y is achiev ed by ring w r aps. •

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•A r ing w r ap may I ndex occur aut om at ically as a r esult of sig nal f ailur e or degr adat ion in sig nal q ualit y Ior nt emrnanu et w ally or k ing chnologie H a ndbook Four th or Edit asTecom m andsed by an ,op er at . Iion f bot h r ing s ar e cu t t og et her, t he n odes on eit her side of t he br eak im m ediat ely wr ap . I f only one r ing is cut , t he nod e in t he d own st ream side of By Cisco Systems, Inc. t he cu t d et ect s t h e sig nal f ailu re and send s t he upst r eam node an I PS con t rol m essage v ia t h e ot her r ing . Then t hat upst r eam nod e also w rap s. I n b ot h cases, t he n odes det ect in g t h e failur e Pub lish er: Cisco Press also not if y ot her st at ions by sending cont r ol m essag es. Pub Dat e: Sep tem ber 1 1, 2 003 SBN: 58 705r -1 Figur e I25 - 31-illust at19 es-2a d ual- fib er failur e and a node t h at h as exp er ienced a Lay er 3 cont r ol plane Pages: failur e11w 28hose DPT int er face is oper at ing in p ass- t h rou gh m ode.

Figu r e 2 5 -3 . D PT Re si li en cy The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

I n nor mal fau lt - fr ee operat ion , dat a pack et s fr om nod e 1 dest in ed f or nod e 4 are sent on t he inner r ing v ia nod e 5. Af t er t he fiber br eak occur s and t he ring w r aps, n ode 1 sen ds dat a pack et s t o node 4 v ia t h e same in ner r in g as befor e b ecause t h e t opology d iscov er y p rocess is as of y et un aw are of an y shor t er pat hs. Nod e 5 t hen wr ap s t his p ack et b ack on t o t h e out er r ing , w here each n ode passes t he p ack et v ia it s t ran sit buf fer u nt il it reaches nod e 4. Not e t hat node 4 d oes not r eceive an d st r ip t he p ack et d irect ly off t h e out er r ing. Rat her , it w rap s t he p ack et b ack ont o t he in ner r ing befor e t h e nor m al pack et - receiv ing pr ocess h andles t he packet . •

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I n t he header of each SRP p ack et , t h e rin g id en t ifier field in dicat es w h et h er t he p ack et or iginat ed • I ndex on t he in ner or out er r ing . I n a w r ap cond it ion, t h e int erm ediat e n odes not e t hat t he r ing- I D is I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion t hat of t he ot her r ing and do not at t em p t t o pr ocess it , on ly for w ar d it . Not un t il t h e packet is By Systems, Inc.o t he or igin al r in g can any node, includ in g t he int end ed r eceiv er , p rocess t he w r Cisco apped back ont pack et . Pub lish er: Cisco Press

At som e p oin t , t h e t opology d iscov er y p rocess det erm ines t h e new r ing or der, and t r aff ic fr om Pub Dat e: Sep tem ber 1 1, 2 003 nod e 1 t rav els dir ect ly v ia t h e out er r ing t o node 4 r at her t h an follow in g t he sub opt im al w r apped I SBN: 1- 58 705 -1 19 -2 pat h v ia n ode 5. Pages: 11 28

Also in Figur e 25 - 3, n ot e t hat nod e 2 has lost it s sof t w are con t rol plane t h r ough eit her failur e or oper at or int er v en t ion . Becau se t he DPT int er face st ill has p ow er , it oper at es in pass- t hr ou gh m ode—m er ely r ep eat in g all packet s it receiv es back ont o t he rin g, t h us bot h m inim izing disr upt ion and pr eser v ing band w id t h, b ecause b ot h rin gs ar e st ill oper at ional. I f node 2 exp er iences pow er of outt he age, nod es 1 analld 3in-see a dual fiber b reak anides d p ercover f orm age t he of The u pdat ed aedit ion b est - selling onet his netas w ork ing r ef erence p rov necessar r in aps edg to re ecov ernologies. . essent ial yan d gcuwt rt ingt ech When t he fault is clear ed , t h e rin g au t om at ically un w rap s. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Topology Discovery Each node on t he r ing per iod ically sen ds t op ology discover y pack et s t o t h e out er r ing. Each node app en ds it s MAC ad dr ess an d specifies w het her it s int er face is w r app ed . The t opology discover y pack et event u ally ret u rn s t o t he sour ce node. Wh en t w o con secut iv e discover y pack et s are sent •and r eceived Table Content w it h oft he sam se r in g in for m at ion, t h e nod e builds a t op olog y m ap of t he r ing. This •m ap is used It ndex o r espon d t o ARP requ est s v ia t he shor t est pat h t o t he sour ce MAC. I f t he pat hs ar e Iequal nt e rn etdist w orance, k ing Teachnologie H a ndbook , Four th Edit ion hash issdon e t o select t he r ing. By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DPT/SRP Packet Formats Ther e ar e t w o t y pes of p ack et f or mat s—cont r ol packet s an d d at a p ack et s. SRP' s Max im u m Tr ansfer Unit ( MTU) is 92 16 by t es, and t he m inim um is 55 by t es. Th e cur r en t Cisco def ault is 44 70 by t es. Bot h p ack et s t y pes use t h e same generic h ead er . •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SRP Version 2 Generic Header All SRP pack et s hav e a com m on 1 6- bit header f orm at , as sh ow n in Figur e 25 - 4.

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Figu r e 2 5 -4 . SRP V er sion 2 Ge ne r ic He ad er

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

This h ead er con t ains t h e follow ing fields: Tim e t o li ve ( TTL) — 8 b it s. Decr em en t ed by 1 each t ime t he pack et t r ansit s a node. To safegu ard again st endlessly looping p ack et s, w hen t he TTL r eaches 0 , t he p acket is st r ipp ed The ufrpdat ion The of t he estTTL - selling ork ber ing rofef nod erence p rov age of om ed t heedit r ing. initbial m ustallbeint wone ice tnet he w n um es on a rides ing tcover o h andle w r ap essentcondit ial anions. d cu tHence, t ing- edgt heet ech nologies. t heor et ical m ax imu m nu mb er of nodes on a r ing is 25 6 / 2 = 1 28. Ri ng id ent ifi e r ( R ) — 1 b it . I ndicat es w het her t h e packet or ig inat ed on t h e inner or ou t er Con iew0 sindicat of t echn t ialant od naetv wor r ing.cise A vov aluerevof es olog t he ies ou t essen er rin g, alu ek ing of 1prinofession dicat es als t he at innall er lev rinels, g. f rom nov ice t o ex pert . Mod e— 3 b it s. I d en t ifies t he t yp e of SRP p acket as a cont r ol p ack et or dat a packet . Table New include 25 - 1 chapt list s ter h es valu es. cov erag e of im por t ant t opics like VoI P and EAP Cov erag of i) cut edge echnet ologies e opt et wor kfing orPreced age en ce bit s. The P rior it y e( Pr —t ing 3 b it s. A tpack pr ior itlik y of 0 t ical o 7 , ncopied romand t he stI P SRP imp lem ent s on ly t w o levels of pr ior it y queue t o w hich t he eigh t Pr iorit y values ar e Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . m apped. I n t ernPar et witory k(inP) g— Tech Hand , Four h Ed is a com pric ehensive 1 bnologies it . An odd parbook it y calcu latted onit ion t he, SRP g en er header . refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e anle d u2p-5t-o-1d. atMe od r ef er t o tshe t op ics t hat are essen t ial t o all Tab e ence Val ue net w or kin g p rof essionals, r egar dless of ex pert ise. Reader V a lue s D w eillscri obtpt ain i on a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on edint egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions a00 b r0oad rReser ang e vof t o00en con cept 1 su reReser v ed comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy 01 0em s,Reser v ed syst pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease 01 1 ATM dat a cell pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t trol h eirm essage net w ork(s. 10 0 Con p ass t o host ) 10 1

Con t rol m essage ( locally buf fer ed f or host )

11 0

Usag e pack et

11 1

Dat a pack et

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SRP Data Packet Figur e 25 - 5 sh ows t he f orm at of an SRP d at a p ack et . Not e t h at t h e Mode field w it hin t he header is set t o 0x 7 ( binar y 11 1) , ind icat in g a dat a packet . •

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Figu r e 2 5 -5 . SRP V er sion 2 Da t a Pa ck et For m at

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern addit SRPnologies genericHand header, f ollow ields in clud ed : et ion w or tkointgheTech bookt he , Four t h ing Ed it fion , isare a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing i na tnion Addpor re ss A er )— 48 bitkin s. gThe g lobally uniq dr ir ess. indu stDrye .stLear howMA t oCincor at e( Dint net w or t echn olog ies in tue o aI EEE LAN/MAC WANad env onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Sou rce MAC Addr ess ( SA) — 48 bit s. The g lobally uniq ue I EEE MAC ad dr ess. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Prot ocol Type — 16 bit s. Not e t h at t h e v alu e cannot be 0 x2 007 , because t his ind icat es a cont r ol p ack et . Refer t o Table 2 5- 2 f or t h e valu es. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on P ay loa d— Variable leng t h. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su remcon ceptckcomp r eh en sion r ets.enThe t ion, and dit ional r esou r ces f or fu rt her st udy . Fra e Che Su m ( FCS) — and 32 bit 3 2b it ad CRC. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Tab le 2 5 - 2 . Pr ot ocol Ty pe s

V a lue

D e scri pt i on

0x 20 07 SRP con t r ol ( discussed in t he nex t sect ion ) 0x 08 00 I P V4 0x 08 06 ARP •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SRP Control Packet Figur e 25 - 6 sh ows t he f orm at of an SRP cont r ol packet . Not e t hat in t h e gener ic header, t he TTL is nor m ally set t o 1 , because t he con t rol m essage w ill be p r ocessed by t h e nex t n ode any w ay . The p r ior it y shou ld b e set t o 7 t o en su r e t hat con t r ol pack et s are t r eat ed w it h p r ior it y on t he •r ing. Table of Content s •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 2 5 -6 . SRP V er sion 2 Con t r ol Pack et Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin essionals, r egarheader, dless of t ex ise.ing f ields are in clud ed : I n addit iong tporof t he SRP generic he pert f ollow Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dwDar ocols, ser re v ices . Fu entis alset t ech matrion is pret ovsided on e e, st ipr naot t ion MAand C Add ss (inv D Aolv ) —ed48 bitndam s. This t onology all 0' s inf f ororcont ol pack because a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t hey w ill be receiv ed b y t he next node any w ay. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag is also extAddr end ed n ot only o new worgklobally ing concep t s, Ibut old , legacy Soue rce MAC ess ( SA) —t 48 bit s.n et The uniq ue EEEalso MACt oad drer ess. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals Prot ocoloper Type at e. — Tools 16 bitand s. SRP gu id con elines t r ol pack f or opt et simare izing 0x 200 syst7. em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Contfor rolt hVeir e rsion 8 s. b it s. The v ersion num ber f or t he Cont r ol Ty pe field . Cu rr ent ly all decisions net w— ork cont r ol m essage t yp es are ver sion 0. Cont rol Ty pe — 8 b it s. I d en t ifies t he t yp e of con t r ol m essage. Table 2 5- 3 list s t h e valu es. Cont rol Che ck sum — 16 bit s.

Cont rol TTL— 16 bit s. This v alue shou ld b e set t o t he sam e generic SRP h ead er TTL t h at t he orig in at or uses for dat a packet s ( t hat is, at least t w ice t he nu mb er of nodes on t he r ing) . The gener ic SRP header TTL for cont rol packet s is st ill set t o 1. P ay loa d— Variable leng t h. Fra m e Che ck Su m ( FCS) — 32 bit s. The 3 2- b it CRC. •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

V aPub luelish er:

Cisco Press

Tab le 2 5 - 3 . Cont r ol Ty pe Va lu es D e scri pt i on

Pub Dat e: Sep tem ber 1 1, 2 003

0x 00

I SBN: 1- 58 705 -1 19 -2

0x 01 Pages:

11 28

Reser v ed Topology discov ery

0x 02

I PS m essage

0x 03 t o 0x FF

Reser v ed

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Multicast Support SRP dir ect ly sup por t s I P m ult icast ( Class D) pack et s. The MAC add resses 0 0: 00 : 5E: xx : x x: x x ar e r eser ved for m u lt icast . Also, t he least - signif icant bit of t he m ost - signif ican t by t e is set as t he m ult icast bit . Finally , t he low er 2 3 b it s of t he Class D I P ad dr ess ar e m app ed t o t he r em ainder of •t he MAC addrTable ess. of Content s •

I ndex

IAll nt em rnult et wicast or k ing chnologie s H a ndbook Edit - enTeabled n odes m at ch , aFour DAthad drion ess of 0 1: 00 : 5E: xx : x x: x x , and b ot h r eceiv e and for w ar d t he p ack et . As m ent ioned ear lier, t he m ult icast p ack et ev en t ually is sour ce- st r ipped By Cisco Systems, Inc. aft er cir culat ing t he ent ir e r ing . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary Cisco dev elop ed Dy nam ic Pack et Tr anspor t / Spat ial Reu se Prot ocol t o pr ov ide a band w id t heff icient rin g t echn olog y opt im ized f or pack et t r anspor t . Nod es are conn ect ed t o t wo count er r ot at ing fib er r ing s—t he inn er and out er r ings. Bot h r ings t ran sm it packet s. Because •pack et s are dest Tableinof atContent ion- st rsip ped and no t oken is r eq uired for rin g access, m ult iple n odes can •t r ansm it sim ult I ndex aneously on diff er ent seg ment s of t he r ing giv ing gr eat er bandw id t h. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

The SRP p ack et Inc. f orm at supp ort s eigh t p rior it y levels copied f r om t he I P pr ecedence bit s, w h ich By Cisco Systems, can be used for int er nal queuing of pack et s t r ansm it t ed by a nod e. The act ual SRP in t er f aces hav e only t wo lev els of queues—a low - and high - pr iorit y queue f or t r ansm it an d t r an sit t r aff ic t o Pub lish er: Cisco Press w hich t he eight lev els ar e m apped. Th e SRP Fair ness Algor it hm ensur es t hat each n ode has fair Pub Dat e: Sep tem ber 1 1, 2 003 access t o t he r ing du rin g cong est ion, but can u se mor e t h an it s fair shar e w hen t her e is no I SBN: congest ion. 1- 58 705 -1 19 -2 Pages: 11 28

DPT/ SRP is r esilien t an d su ppor t s p lu g- and - play deploy m en t b ecause of it s ab ilit y t o heal r ing br eaks by im plement in g r ing w r aps an d t ran sp arent pass- t hr oug h mod e feat ur es.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: • •

How d oes D PT/ SRP diff er fr om ot h er r ing t echnologies such as Tok en Rin g an d Table?of Content s FDDI I ndex

I nt e rn et2 w:or k ing Te d chnologie s HSRP a ndbook , Fouren th tEdit ionet How oes D PT/ im plem p ack

p rior it y ?

By Cisco Systems, Inc.

3:

What m ech anism det erm ines w hich rin g a nod e sh ould send a dat a packet t o r each anot h er node?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

4:

How d oes D PT/ SRP recover f r om a f iber br eak?

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Whit e pap er : " Dy nam ic Pack et Tr anspor t Technolog y and Per f orm an ce, " Cisco Sy st ems, 2 000 , w w w .cisco. com . •

Table of Content s

•

I ndex

•I nt Whit pap er Te : " Spat ial Reuse Pr ot,ocol Techn ology ," Cisco Sy st ems, 2 000 , w w w .cisco. com . e rn et e w or k ing chnologie s H a ndbook Four th Edit ion By Cisco Systems, Inc.

• I n for m at ional RFC 28 92: The Cisco SRP MAC Lay er Pr ot ocol , Tsiang, D. ( Cisco Sy st ems) and G. SuwPub alalish( er: Cisco CiscoSyst Press em s) , Augu st 20 00, w w w .iet f .or g. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Glossary Terms t ra nsi t ing t r af fi c.

• •

Packet s t hat t he DPT node receiv es on it s DPT in t er f ace and t hat are for w ar ded u nchang ed ofPT Content t o t he nTable ex t D n odes in t he r ing. An ex am ple is a DPT p ack et w it h a d est inat ion MAC I ndex add ress for a st at ion ot her t h an t his nod e.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

t ra nsm it t e d t ra ff ic. Pub lish er: Cisco Press PubPacket Dat e: Sep 1 1, 2 t003 s ftem or ber w hich his

DPT nod e is t he sour ce MAC st at ion. Th is inclu des pack et s generat ed by I SBN: t he1- nod 58 705 e -1it19 self -2 and also t r af fic t h at t h e node receiv es on anot her of it s in t er f aces and for w ar11ds Pages: 28 ou t it s D PT int er face.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 26. Extensible Authentication Protocol (EAP) • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Descr ibe EAP.

By Cisco Systems, Inc.

Under st and PKI supp ort w it h EAP. Pub lish er: Cisco Press

Descr EAP Pub Dat e: ibe Sep tem berTr 1 anspor 1, 2 003 t

Lay er Secur it y ( TLS) .

I SBN: 1- 58 705 -1 19 -2

Under st and Prot ect ed EAP ( PEAP) . Pages: 11 28

I nt r odu ce v ar ious EAP im plement at ion s. Ex t ensib le Au t hent icat ion Pr ot ocol ( EAP) is an au t hent icat ion pr ot ocol t hat w as defin ed t o supp ort m ult iple au t hent icat ion m echanism s. Point - t o- Point Pr ot ocol ( PPP) con nect ion s t y pically negot e ed t heedit aution hentoficat ion p rot ocol dur ing he con ion 's rLink Con t rol Prides ot ocol ( LCP) The u iat pdat t he b est - selling allin-tone netnect w ork ing ef erence p rov cover ageph ofase. This r equir t o supp ortt ech t henologies. aut hent icat ion m et h od bein g used . essent ial anesd PPP cu t t ingedg e Alt hou gh aut hent icat ion is not r eq uir ed for PPP conn ect ions d ur ing t he conn ect ion' s LCP p hase, t he enCon dpoint cisesov negot er v iew iat e s of w hich t echn aut olog h enies t icat essen ion tpr ialottocol o n ett o wor use k ing t o pr estofession ab lish t als he conn at allect levion. els, They f rom m ay choose nov ice tnoo ex aupert t h, .PAP, or CHAP au t hent icat ion. EAP d ef er s t h e negot iat ion of t his aut h en t icat ion m ech anism un t il m ore in for m at ion ab out t he conn ect ion can b e gat h er ed. Th er e New gr chapt er sconcer include covt oerag of eg imrit por t ant likeion VoImechanism P and EAPs, and EAP is an has been ow ing n as t heeint y of auttopics hent icat at t em pt t o p rov ide a fou ndat ion t o secur e t his p ar t of net w or k access cont r ol. Man y vend or s are Cov erag e of cutEAP t ing int edge t echn ologies e opt et wor k ing and st or age bu ild in g su ppor t for o bot h clien t and lik serv er ical app nlicat ions. Aut htored Sypr stot ems, ldw EAP ide leader in net or king f or and t he Itnhis t erchap n et . t er cov ers This chap er ex by plorCisco es t he ocolwitor self. is defined in wRFC 22 84, som e of t he specifics defined in t hat RFC t o help you un derst an d t h e basis of t he pr ot ocol. You Iwnill t ern et w or keinof g Tech nologies Hand book Four talong h Ed it ion a com pritehensive refer ence t hat see som t h e adv ant ages of u sing, EAP, w it ,h is t he secur y concer ns t h at m ak e t his enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing pr ot ocol so at t ract iv e in a v ar iet y of im plem en t at ions. Rem ot e Aut h en t icat ion Dial- I n User tServ echnologies. er ht he er m cep t s, tthese echn ologies, anTh d devices used in tibes odayh' ow s net w orkUS ing ice ( RADI Mast US) is elpftul in s,adcon dr essing con cer ns. is ch apt er descr RADI indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . can be used as a b ack - end ser v ice t o pr ov ide aut h en t icat ion sup por t f or t he user . Wit h t h is Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, m or e- com plet e pict ur e of t h e EAP aut hent icat ion pr ocess, y ou w ill look at dif ferent and speed, is sbook is aincom d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all im plem ent att hion of EAP t h eplet netewan or k. net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

The EAP Protocol The p r ot ocol sp ecificat ion for EAP is n ot com plicat ed . The au t hent icat ion pr ocess has on ly a f ew st eps. You w ill t ake a closer look at each of t he st eps and see som e of t he d iff er ent opt ions av ailab le for t he client and t h e aut hent icat or . •

Table of Content s

•EAP st art s w hen I ndext h e link est ablish ment ph ase is com plet e. The EAP n eg ot iat ion t ak es place in t he I nt rn etat w or k ing Te chnologie s H a dat ndbook , Four ion et . Figur e 26 - 1 sh ows t he d if fer en t f ield s for EAP nfeorm ion field of t he PPP a link laytherEdit pack pack et s and t he leng t h of each field in oct et s. By Cisco Systems, Inc. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Figu r e 2 6 -1 . EAP Pack e t For m a t

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . er s tinclude erag of imen por antant opics and Figur eNew 26 - chapt 1 sh ows he f ive dcov iffer ente elem t s t of EAP plike ack VoI et . P The fir EAP st t hr ee f ields ar e r eq uir ed . Depend in g on t h e t y pe of EAP pack et being sen t , t he ot her fields m ay also b e pr esent . e of cut t ing t echn Each Cov fielderag is discussed in tedge he follow inologies g list : lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Code— The Cod e field of an EAP pack et ident if ies t h e t y pe of EAP pack et being sen t . This I n t ernfield et w or in g Tech Hand Four Ed itcodes: ion , is a com pr ehensive refer ence t hat iskone oct etnologies in len gt h andbook has ,one oft hf our enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing - Request indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, onseis a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all and speed, -t hResp is book net w or kin g p rof essionals, r egar dless of ex pert ise. - Success Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e - ot Failur e and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on har dw ar e, pr ocols, a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions I de nt i fi er — The I dent if ier f ield is also one oct et in lengt h. I t con t ains an ident ifier n um ber t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . for t he p ack et . I t is used t o mat ch r equest pack et s w it h t he pr op er r eply p ack et . Ther e Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy m ight be a need f or t he client t o r et r ansmit a r equest . Th is ret r ansm ission is requ ired t o syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich use t h e same id en t ifier as t he pr ev ious at t em pt so t h at t h e aut h en t icat or can p rop er ly pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease dist ingu ish bet w een r et r ansmissions and n ew requ est packet s. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Le ng t h— The Leng t h field is a t w o- oct et f ield t hat defines t h e len gt h of t he EAP p ack et . The v alue of t he Lengt h f ield includes t he leng t h of t he EAP pack et 's Code, I dent ifier , Leng t h, and Dat a fields. Any dat a af t er t he ran ge ident if ied by t he Len gt h field shou ld b e consid er ed pad ding of t he PPP dat a link lay er an d sh ould be ign ored by EAP. Ty pe — The Ty pe f ield of t he EAP p ack et ind icat es t h e t y pe of dat a cont ained in t he pack et .

This f ield depend s on t he p ack et 's Code f ield. A code of r equest or response ind icat es t h at t he Typ e field is set . Th is field is on e oct et in leng t h. Th e Neg at ive Ack now ledgm ent ( NAK) t y pe m ay b e used in a r esponse pack et only t o indicat e t h at t h e aut h en t icat ion t y pe is n ot supp ort ed . All EAP imp lem ent at ions are requ ir ed t o sup por t t h e fir st f our t y pes list ed n ex t . Not e t h at if t he packet is a success or f ailur e code pack et , t his f ield has no r equir ement . The d iff er ent t yp es are as follow s: - I de nt i t y — The aut hent icat or gener ally u ses t he ident it y t yp e in t h e fir st p ack et of Table of Content s t he aut hent icat ion pr ocess t o quer y t he client . Th is is t he in it ial requ est for t he clien t I ndex t o send it s ident it y for au t hent icat ion.

• •

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, - N otInc. i fi ca t i on — Pub lish er:

Disp lays a m essage t o t he client fr om t he aut hent icat or . Th is can be a w ar nin g m essag e or a passw or d ex pir at ion t im e. Th is m essage is n ot r equir ed t o be sen alt hou gh t he EAP im plement at ion m ust suppor t it s use. Ciscot ,Press

Pub Dat e: Sep tem ber 1 1, 2 003

- N AK — This t y pe is v alid on ly in r esponse pack et s. I t is used wh en an un accept ab le aut h en t icat ion t y pe is requ est ed. For ex amp le, t he au t hent icat or m ight r eq uest PAP 11 28 aut h en t icat ion , and t h e client m ig ht su ppor t only CHAP. Th e client sen ds a NAK so t hat t he aut hent icat or r equ est s an alt ern at ive aut hent icat ion t y pe.

I SBN: 1- 58 705 -1 19 -2 Pages:

- MD 5 - Cha ll eng e— The challen ge m essag e t o t h e peer, mu ch lik e a CHAP r eq uest in a st an dar d PPP negot iat ion . The p eer m ust respond w it h eit her anot h er MD5The u pdat edChedit ion eofort he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of alleng a NAK. essent ial an d cu t t ing- edg e t ech nologies. - One - Ti m e Pa ssw or d ( O TP) — The challen ge m essag e for p er f orm ing t h e aut h en t icat ion v ia an OTP sy st em. The r esp onse t o an OTP t y pe p ack et m ust be eit her Con cise ov er NAK orv aiew t yspeofoft echn OTP.olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . - Gene r ic Tok e n Ca rd— Defined for u se wit h v ar iou s t ok en car d im p lem ent at ions. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP The au t hent icat or sends t he m essage t yp e cont aining a messag e r eq uir in g user in put . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Ty - da t by a —Cisco The Ty dat a wfield is ide 0 b leader yt es or in g rnet eatw eror , depend Autpe h ored Sypest ems, or ldw king f oring t heon I ntt he er nTy et .pe f ield of t he EAP packet . Most ly t his f ield con t ains d isplay m essag es t o t h e client in a r eq uest pack et . I f a NAK p ack Hand et , t hbook is field contt hainEd s itinf orm onprwehensive hat au t hent icat ion tmet I n t ernt he et wpacket or k in g is Tech nologies , Four ion , isataion com refer ence hat h od is accept able. I f t he Ty pe f ield is MD5 Challenge, t h e cont ent s of t h e Ty pedat a field enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net wcor orkrelat ing e t o t he PPP CHAP f ields of Valu esize, Value, and Nam e. ( See t he PPP CHAP RFC [ 1 994 ] ) If t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork.ing t he Typ e field is r epr esent at iv e of an OTP or gener ic t ok en car d, t h e Typ edat a f ield indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . cont for man atdion r equed ir ed by er t h se on ser secur v er f or e or aut h en opt t icat ionnet . w or k in g, scalabilit y, Com plet e ains w it h innew u pdat chapt it yt,hst age, ical and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Using RADIUS for EAP Authentication On e of EAP's best pr oper t ies is t he ab ilit y t o add RAD I US as a back - end aut hent icat ion ser v ice. Wit h t he u se of a RAD I US ser ver , t he EAP au t hent icat ion var ies a lit t le f rom a t r adit ional RADI US aut h en t icat ion . I n a t r adit ional RADI US aut h en t icat ion , t he Net w or k Access Serv er ( NAS) •pr om pt s t he Table user of f orContent t he aus t hent icat ion met h od t o be u sed. When t he clien t r esp onds t o t h e •r eq uest by t he I ndex NAS, t h e NAS cr eat es an access- r eq uest pack et t o send t o t he RAD I US ser ver b y It rntanslat e rn et wing or k ing chnologie s Ha ndbook Four int th Edit ion app r opr iat e RADI US at t r ibu t es for t h e ser v er . t hatTeaut h en t icat ion m et,hod o t he The ser Systems, ver r esp Inc. onds wit h eit her an access- accept or access- r eject r esponse pack et . When t he By Cisco NAS r eceiv es t he r esp onse, it int er pr et s t he r esult s f rom t he au t hent icat ion m et hod and sends t hem t o t he client , eit her accep t ing or r ej ect in g t he user aut h en t icat ion . This is slight ly diff er ent Pub lish er: Cisco Press w it h t he u se of EAP as t h e aut h en t icat ion m ech anism. Pub Dat e: Sep tem ber 1 1, 2 003

SBN:NAS 1- 58 705 -1 19 -2 When tI he uses RADI US as a back- en d serv er f or t he EAP aut hent icat ion, t h e NAS is not r eq uir Pages: ed t o 11 su28 ppor t t he au t hent icat ion met h od b eing u sed. I n t h is case, t he NAS oper at es as a pr ox y for t he au t hent icat ion b et ween t he clien t an d t h e RADI US serv er and t r anspar ent ly p asses t he aut hent icat ion m essages bet w een t h e client and t he b ack - end ser v er. The NAS is n o long er inv olved in t he aut hent icat ion p rocess. I t oper at es in p rox y m ode, sending t h e EAP messages bet w een t h e t w o r emot e peer s. Th is generic p lat for m f or aut h en t icat ion now allow s vend ors t o dev and d if fer t hent icat ionallmet ods net t h at ar eing un rderst ood by t he clien t anage d t h of e The elop u pdat ed use edit ion ofent t heau b est - selling in-hone w ork ef erence p rov ides cover ser v er, wit h out con cer n for sup por t on t h e NAS. The NAS is r eq uired only t o bun dle t h e EAP essent ial an d cu t t ing- edg e t ech nologies. m essages and send t hem t o t he RADI US ser ver .

Tw o nCon ew cise RADIov US t r ibut h aveolog been ed t tial o supp ort EAP. wor k t als ogetather o pels, r ovide er vatiew s ofest echn ies add essen t o n et wor k ingThprey ofession all tlev f rom RADI US ort . . novEAP ice t supp o ex pert The f irNew st ischapt t he EAPMessag ecov aterag t r ibut t send t het opics EAP inf or VoI matPion f rom er s include e e. of Iim por t sant like and EAPt he clien t t o t he ser ver , and v ice ver sa. The NAS can sen d t he inf orm at ion in one or m or e EAP- Messages. The serv er can also use Covterag h is at e tof r ibut cutet ing t o redge esp ond t echn w it ologies h a challen lik e ge, opt accept ical n et, wor or rkejing ectand pack stet or. age I t is assu m ed t hat t his au t hent icat ion met h od w ill b e used f or st r ong cr y pt og rap hy or ot her sen sit iv e aut h en t icat ion Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . m et hods. I n t ern et w or kRADI in g Tech nologies , Four t h Messag Ed it ion e, is com pr ehensive refer ence t hat The second US at t r ibut e tHand hat wbook as add ed is Auat hent icat or . The Messageenables net or w oratkin g p reofessionals d im plem t cont em y art int serat net w orkt ing Aut h en t icat t r ibut maint ain s t oheuninderst t egr itand y ofan t he RADI USenpacket s anpor d tar hw t acks o the t echnologies. Mast t he t erect m s, cep t s,a tin echn anet d . devices odaybe ' s used net w ork ing RADI US EAP ser v ererby p rot ingcon t he dat sid eologies, t he p ack This at tused rib ut einmt ust indut st t o incor por at er net g t echn ies in, taccep o a LAN/ env ir onm ent any imry e . t Lear her enishow an EAPMessag e eatint t r ibut ew inort hkin e RADI USolog r equest t , orWAN challenge p ack et.s. e w it h new an dicat u pdat edt rib chapt opt ical net w g, scalabilit y, et ICom f t heplet MessageAut hent or at ut e er is snon ot psecur resenit ty ,wst it hortage, he EAPMessag e or atkt rinibut e, t h e pack and speed, t h is book a com plet an detu' pt o-egr d atitey rcann ef er ence t he t op ics t hat2 6are essen should be d iscar ded, bisecause t h e epack s int ot b et over ified. Table 1 sh owst ial t het ot wall o net w RADI or kin US g p rof new at tessionals, r ib ut es andr egar t h eirdless I ETFofatex t r pert ibut eise. n um ber s. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re entsion and et enm t ion, ad dit ionalI U r esou r ces fAut or fuhe rt her udy Tab le con 2 6cept - 1 . comp I ETFr ehAt r i but e rNu berand s f or RAD S EAP nt st i ca t i. on Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich At t at r ibe.utTools e D elines e scri ptf or i on prI ETF of essionals oper and gu id opt im izing syst em per for m ance w ill incr ease um ct b er prNodu iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t hEAPeir net w ork s. 79 Message En cap su lat es EAP inf or m at ion t o be t r an sf er r ed b et ween t he client and t h e RADI US ser v er 80

Messag eAut h en t icat or

En su res m essag e int egr it y by encr y pt ing t he EAP m essag es w it h t he RAD I US secret key

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

A Typical Authentication Conversation Now t h at y ou hav e a b et t er id ea of how EAP w or k s, and you h ave seen t h e r ole of a back - end RADI US serv er in t he au t hent icat ion p r ocess, let ' s look at a t y pical aut hent icat ion conv ersat ion w it h an EAP clien t , a NAS, and t he RADI US ser ver . Ther e ar e dif fer en t im plement at ions of EAP in •sev er al diff erent Tablenet of Content s ch it ect u res. Each imp lem ent at ion follow s t h e same b asic pr em ise for w or k ar •t he aut hent icat I ndex ion flow . Figur e 26 - 2 illust r at es a b asic au t hent icat ion packet flow f or RAD I US IEAP nt e rninv et wolv or king ing a Teclient chnologie H a ndbook th Edit , a sNAS, and ,aFour RADI US ion ser v er . By Cisco Systems, Inc.

Pub lish er: Cisco Press

Figu r e 2 6 -2 . RAD I US EAP Au t h en t i ca t ion Pa ck et Flow

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

[ View full size im age]

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

PKI Support with EAP What abou t t h e abilit y t o use digit al cer t ificat es w hen p er f orm ing user aut hent icat ion w it h EAP? Pub lic Key I nf r ast r u ct u re ( PKI ) is t he use of digit al cer t ificat es. PKI is a sy st em d esign ed t o m anage asy m m et r ic cr yp t ogr aph ic key s t o ensur e t h e v alid it y of t he d at a b eing p assed. Th is •dat a is likely Table aut h of enContent t icat ions d at a f or a specific user and f or a specific u se, w hich is valid for only •a p er iod of t im I ndex e. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Tw o n ew em er ging By Cisco Systems, Inc. st andar ds for EAP use t h ese cer t if icat es—EAP- TLS an d PEAP. Each off er s a dif fer en t per spect iv e. Neit her is bet t er or w or se t han t he ot her. How ev er, each m et h od has dist inct p r opert ies and is suit ed t o d iff er ent im p lem ent at ion requ irem ent s. The u se of digit al Pub lish er: Cisco Press cer t if icat es f or user aut h en t icat ion is a lit t le m or e com plicat ed simp ly becau se of it s nat u re. Th e e: Sep tem ber 1 1, 2 003 nex Pub t t wDat o sect ions d iscuss t h ese ex t en sion s t o EAP because t hey ar e a gr ow ing requ irem en t f or I SBN: 58 705 -1 19 new EAP im1plement at-2 ion s. Pages: 11 28

EAP Transport Layer Security (EAP-TLS) Tr anspor t Lay er Secur it y ( TLS) is t he newest I ETF ver sion f or t he Secur e Socket Lay er ( SSL) The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of pr ot ocol. TLS is SSL ver sion 3. 0 . TLS aut hent icat es t h e user ' s ident it y f or bot h t h e aut h en t icat ion essent ial an d cu t t ing- edg e t ech nologies. ser v er and t he client . Each uses it s p riv at e k ey and cer t ificat e t o ver ify t h e ot her end point . Fir st t he ser ver sends it s ident it y inf or mat ion . The clien t v er if ies t he cert if icat e wit h a t r ust ed Cer t ificat Autov h orit ( CA) ver .olog Aft ies er tessen he clien ies tkhe er, it sen dsatit sallcer t ificat to Con ecise er vyiew s ofser t echn t ialt ident t o n etifwor ingser prvofession als lev els, ferom t he ser ver t o ident if y t he u ser at t em pt in g t o aut h en t icat e. The ser v er ch eck s t h e cer t ificat e f or it s nov ice t o ex pert . v alid it y on t he CA ser v er t o conf irm t he u ser 's id en t it y. This is k now n as m ut u al aut h en t icat ion . Each New par t ychapt v erif er iess tinclude h e identcov it y erag of t heeof otim herpor t ot ant hav et opics EAP success w and it hout t r ansm it t ing any like VoI P EAP passw ord s across t h e link . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in Protected EAP (PEAP)

net w or king f or t he I n t er n et .

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Pr ot ect ednet EAP PEAP) t he sam pr derst inciples ev er,em wpor it h ar PEAP henet w ork ing enables w or(kin g p r uses ofessionals t oe un andas anEAPd imTLS. plemHow en t cont y intter aut h en t icat ion is a lit t le diff er ent . I t uses PKI only t o aut h en t icat e t he serv er t o t he This t echnologies. Mast er he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' sclien net wt .ork ingis called ser v er side cert if icat es. Th e pur pose of t h is t y pe of aut h en t icat ion is t h reefold . Fir st , it indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . allowplet s t he t t o ask sered verchapt t o prer ovseon it ssecur identitityy, w it s cer t ifical icatnet e. Th is kis m uch lik e any Com e wclien it h new an d tuhe pdat stitorhage, opt w or in g, scalabilit y, pu blic Web sit e t h at u ses SSL. When a u ser v isit s a Web sit e u sin g SSL ( HTTPS in t h e br , and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essenow t ialser t o) all tnet he wser ver is r equir ed t o pr ov ide it s cer t ificat e t o p r ove t h at it is t he h ost y ou are t ry ing t o or kin g p rof essionals, r egar dless of ex pert ise. est ablish a con nect ion w it h. Th e second p ur pose of using PEAP is t o allow f or flex ib ilit y in t h e Reader user auts hwen illt icat obt ain ion .aI g t reat is n ot er alw un der ay sstpr anact ding icaloffor LAN ev er and y clien WANt tnoetbe w or issued k ing, p a ar cer t icu t if icat lar lye t hoebe used har for dw client ar e,aut prhent ot ocols, icat ion. and PEAP ser v ices allow inv s olv f or ed alt. ern Fu ndam at ive ent client al -t ech sidenology aut hent inficat or mat ion ion m etishod pr ov s, ided on a includin b r oad gr ang OTP. e of The intt egr h irdal, and sy st em f in al, s and pur serv p oseices, of u sin in clud g t he ingser det v er ailed sid e descr cer tipt ificat iones,isrev t h iew at t hquest e session ions tiso encr en suyp ret ed conwcept it h t comp he serr ver eh encert sion if icat ande rbefor et en teion, t heand useradsend dit ional s t heir r esou usern r ces amf or e tfu o rt t hher e ser stvudy er . .Th is Cov pr event eragseat ist acker also ext s f rom end ed ex n t rot actonly in g user t o new namnes et wor f rom k ing t heconcep au t hent t s,icat bution also p ack t o et old . er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

EAP Implementations Now t h at y ou hav e a b et t er und er st andin g of w h at EAP is and som e of t he p rot ocol' s diff erent ext ensions, w e can look at a few of t he dif fer en t im plem en t at ions of such a pow er fu l aut h en t icat ion m ech anism. •

Table of Content s

•The u se of t his I ndex pr ot ocol is g row in g. EAP w as int r odu ced in t he w ir eless access aut hent icat ion Im ntodel. e rn et wThe or k ing Te chnologie s Hr aeq ndbook Editicat ion ion for Lay er 2 access t o t he net w ork ar e clear. I t ad van t ages of uir ing, Four autth hent pr ohib it s host s f rom obt aining a Lay er 3 ad dr ess u nt il af t er aut h en t icat ion . This concept was By Cisco Systems, Inc. exp anded t o LAN- sw it ched en vir onm ent s. By u sin g EAP f or Lay er 2 access on a sw it ch por t , net w or k adm inist r at or s hav e comp let e con t rol over w h ich users are allow ed t o access t h e LAN. Pub lish er: Cisco Press Add it ion ally , t h is m et h od of aut hent icat ion pr ovid es a m ean s of cont r ollin g t hat user ' s VLAN, Pub Dat e: Sep tem ber 1 1, 2 003 r eg ar dless of t h e phy sical sw it ch por t . I t uses RADI US t o p r ovide t he at t r ibu t es for such I SBN: 1- 58 705 19 -2 adm inist r at ive con-1t rol. Pages: 11 28

I n addit ion t o t hese im plem en t at ions, EAP has b een ext end ed t o rem ot e- access m et h ods. EAP can be app lied t o t rad it ion al dialup conn ect ions, as w ell as t o VPDN con nect ion s w here t he endp oin t is a r out er . The NAS need s only t o su ppor t EAP as a PPP aut hent icat ion t y pe f or t his im plem ent at ion . The au t hent icat ion met h od u sed inside EAP need n ot b e su ppor t ed by t h e NAS it selfu, pdat as discussed simallplyinp rox t he au ing t hent icat ion t op rov t h eides RADI US ser v er. The ed edit ionearlier of t he. bThe est -NAS selling oneies net w ork r ef erence cover age of Figur e 26 3 sh ows each of t hese EAP im plem en t at ions—w ir eless, r em ot e access v ia dialup , and essent ial an d cu t t ing- edg e t ech nologies. sw it ch ed LAN. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Figu r e 2 6 -3 . Ph ysica l Topologi es f or D if f er e nt I m ple m en t a t i on s of EAP New chapt er s include cov erag e ofAu im por t antt itca opics like VoI P and EAP t h en t ion Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Wit h t he g r owin g u se of EAP in net w or k aut h en t icat ion , w e ar e seeing an increase in nat ive supp ort f or su ch au t hent icat ion mechanism s. Micr osoft Wind ow s operat in g sy st em s n ow ship

w it h nat iv e su ppor t for EAP au t hent icat ion of n et wor k conn ect ions. Linux d ist r ibu t ions also supp ort EAP as a v alid aut hent icat ion m et h od. Cisco Sy st ems has alr ead y built in sup por t f or all t hese net w or k aut h en t icat ion im plement at ion s. Ot her v endor s ar e w or k in g t ow ard t h is en d.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary As y ou hav e seen, EAP is a pow erf ul means of p r ovidin g u ser au t hent icat ion for n et w or k access. I t s pop ular it y is gr ow ing as net w or k adm inist r at ors and vend or s recogn ize it s flexib ilit y . Fr om a t r adit ional MD5- Challen ge t o digit al cer t ificat es, adm inist rat or s can use a st r ong au t hent icat ion •m ech anism t Table Content hat mofeet s t h es r eq uirem ent s of t h eir secur it y policies. EAP cu r rent ly cov ers •im plem ent at ion I ndex s fr om w ir eless t o sw it ched LAN au t hent icat ion. I t is clear t h at EAP is an Iemer nt e rnging et w orst k ing chnologie s ill H a ndbook ion andTeard t h at w cont inu, Four e t othexEdit pan d it s role in t he net w ork s of t om or r ow. By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: • •

What f ield of an EAP p ack et ident if ies wh et her t he m essag e is a r equest , r esp onse, Table of Content success, or f ailusre? I ndex

I nt e rn et2w:or k What ing Te chnologie H a ndbook Four th Edit ion EAP is t h e prsimar y b en, ef it of u sing

as an aut h en t icat ion m ech anism?

By Cisco Systems, Inc.

3:

What t w o RADI US at t r ibut es ar e u sed in EAP aut hent icat ion?

Pub lish er: Cisco Press

4:

Does EAP supp ort ser v er - side cert if icat es, clien t - sid e cer t if icat es, or bot h?

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • RFC 2 284 , PPP Ext en sible Aut h en t icat ion Pr ot ocol, ft p: / / f t p. isi. edu/ in - not es/ rf c228 4. t xt •

Table of Content s

•• RFC 2 716 ,IPPP ndexEAP- TLS Aut hent icat ion Pr ot ocol, ft p: / / f t p. isi. edu/ in - not es/ rf c271 6. t xt I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Inc.US • Cisco RFC 2Systems, 869 , RADI

Ex t en sions, w w w .iet f .or g/ rf c/ rf c2869 . t xt

Pub lish er: Cisco Press

• I nPub t erDat nete: Dr aft : Pr ot ect ed EAP Prot ocol , w w w .iet f .or g/ in t er n et - d r aft s/ dr aft - josefsson - pp pext Sep tem ber 1 1, 2 003 eap- t ls- eap- 05 .t x t I SBN: 1- 58 705 -1 19 -2

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Part V: Bridging and Switching Ch apt er 27 Tr an sp arent Br idging • •

Ch apt er 28 Mixed- Media Br id ging Table of Content s

Ch apt er 29 Sou r ce- Rou t e Br id ging I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ch apt er 30 LAN Sw it ching and VLANs

By Cisco Systems, Inc.

Ch apt er 31 Asy nchr onou s Tr ansfer Mod e Sw it ch in g

Cher: aptCisco er 32 MPLS Pub lish Press Pub Ch Datapt e: Sep 1 1,a 2Link 003 er tem 33ber D at

Sw it ching

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 27. Transparent Bridging Obj e ct i ve s • •

Table of Content s

Under st and t r anspar en t b ridg e pr ocesses of lear ning , f ilt er ing, for w ard ing, and flooding . I ndex

I nt e rn Ex et wplain or k ingt he Te chnologie H a ndbook Four th -Edit ionalg orit h m . p ur poses of t he sp ,anning t r ee By Cisco Systems, Inc.

Descr ibe t he br idg e and por t mod es in a sp annin g- t r ee net w ork . Pub lish er: Cisco Press

Tr anspar ent b r id ges w er e f irst developed at D ig it al Eq uipm ent Cor por at ion ( Digit al) in t he ear ly Pub Dat e: Sep tem ber 1 1, 2 003 19 80s. D ig it al subm it t ed it s w ork t o t h e I nst it ut e of Elect r ical and Elect r onic Engin eer s ( I EEE) , I SBN: 58 705 -2 w or k int o t he I EEE 802 . 1 st an dar d. Tr anspar ent br idges ar e v er y p opular w hich in cor p1-orat ed-1 19 t he Pages: 28 8 02. 3 net w or ks. Th is ch apt er pr ov ides an over view of t r anspar ent br idgin g's in Et her net /11 I EEE han dling of t r aff ic and pr ot ocol comp onent s.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Transparent Bridging Operation Tr anspar ent b r id ges ar e so nam ed becau se t heir pr esence and op er at ion ar e t r anspar en t t o net w or k host s. Wh en t r anspar ent br idges ar e pow er ed on, t hey lear n t he w ork st at ion locat ions by an alyzin g t h e sour ce addr ess of in com ing f ram es f rom all at t ached net w ork s. For exam ple, if •a b r id ge seesTable of Content s on por t 1 fr om Host A, t he b ridg e concludes t h at Host A can b e a fr am e ar r ive •r eached t hr oug I ndex h t he segm en t conn ect ed t o p ort 1. Thr ough t h is pr ocess, t r anspar en t b rid ges Ibu nt ild e rn et or k ing( tTe s Hparocess) ndbook , ,Four th Edit a wt able h echnologie lear ning su ch as tion h e one in Figur e 27 - 1. By Cisco Systems, Inc.

Pub lish er: Cisco Press

Figu r e 2 7 -1 . Tr a nspar e n t B r idge s Bu il d a Ta ble Th at De t e r m in es a Host ' s Accessibi li t y I SBN: 1- 58 705 -1 19 -2

Pub Dat e: Sep tem ber 1 1, 2 003

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com h new pdat edbasis chaptfor er st ron secur y , din st or optaical net in g, ed scalabilit The bplet r id e gewuitses it s tan abdleuas t he af fic f orwit ar g.age, Wh en fr am e wisorr keceiv on on ey,of and speed, t h is book is a com plet e an d u pt od at e r ef er ence t o t he t op ics t hat are essen o all t he br idge's in t erf aces, t h e br idge look s u p t h e fr am e's d est inat ion add r ess in it s int er nalt ial t abtle. net w or kin g p rof essionals, r egar dless of ex pert ise. I f t he t ab le con t ains an associat ion bet w een t he dest in at ion ad dr ess an d an y of t he br id ge's por t s aside f r om t he one on w hich t he fr am e w as r eceiv ed , t he fr am e is for w ar ded ou t t h e Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e indicat ed por t . I f no associat ion is f oun d, t h e fr am e is flood ed t o all por t s ex cept t he in boun d har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on por t . Br oad cast s an d m u lt icast s also ar e f lood ed in t his w ay . a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tTr o anspar en su reent conbcept comp r eh en sionisolat and e r etint enr aseg t ion, ment and ad dit ic, ional r esou ces fcin or gfut rt st udy . r id ges successfully t r aff t her eb y rredu heher t r aff ic seen on Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy each ind ividu al seg m en t . This is called filt er ing an d occur s w h en t he sou rce an d d est inat ion MAC syst em s, prr esid ovideinon g at he m orsam e r ealist ic epict e ace. of t he ld ally n et w ingesennet virwonm s in w add resses e br idg intur erf Filtrealerin w g or u su imorpkrov or k ent r espon sehich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease t im es, as seen by t he user . Th e ext ent t o wh ich t r aff ic is r ed uced an d r esponse t im es are pr ct iv itdepend y an d im pr ov e eff iciency, t heent r eader ake iv mor cost imodu pr oved s on t he v olum e of help int ering segm t r aff icmrelat e teo in t hteelligent t ot al t,raf fic,- eff as icient w ell as decisions for t h eir net w ork s. t he volum e of b road cast and m ult icast t r aff ic.

Bridging Loops

Wit hou t a br idge- t o- b rid ge pr ot ocol, t h e t r anspar en t - br idge alg or it h m f ails w h en m ult iple p at hs of br idg es an d local- ar ea net w or ks ( LANs) ex ist bet w een any t w o LANs in t he in t er n et w or k . Figur e 27 - 2 illust r at es such a br idg in g loop .

• •

Figu r e 2 7 -2 . Br i dgi ng Loops Can Resul t i n I n a ccu r at e For w ar di ng a nd n in sg i n Tr an sp ar e nt Br i dgi ng Env ir onm e n t s TableLe of ar Content I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Sup s a fed ramchapt e t o er Host Bot hitbyrid r eceive t h e net fr am e kand r ect ly learn Compose plet et hat w it hHost new Aansend d u pdat s onB.secur , stges or age, opt ical w or in g,cor scalabilit y, tand hat speed, Host A tis on segm ent 2. Each br idg e t hen for w ar ds t h e fr am e ont o seg ment 2. h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Unfor t ukin natgely, on ly w illr egar Hostdless B r eceiv e pert t w oise. copies of t he fr am e ( once f rom br idge 1 and on ce net w or p rofnot essionals, of ex fr om br id ge 2 ) , bu t each b rid ge now believ es t hat Host A r esid es on t he sam e segm ent as Host B. Wh en Host B ain r ep lies t o Host e, botof h LAN br idges ill r eceiv and subsequent Reader sw ill obt a g reat er unA's derfrstam an ding andwWAN n et weor k ing, p ar t icu larlylyf ilt t her e t he rhar ep lies ecause t h e brand idgeser t able w ill t hndam at t h eent dest ( Host is on e same dw arbe, pr ot ocols, v ices invindicat olv ed .eFu al inat t echion nology infA) or mat iont his pr ov ided on net or k rseg asegr t h ealfrsy am a b rwoad angment e of int st e's em ssour andce. serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ICov n addit b asic pr oblem s, nt he p rolif er at ion of t br in net w or ks eragion e ist o also extcon endnect ed nivotit yonly t o new et wor k ing concep s, oadcast but also m t oessages old er , legacy w it hem loop ep r esent a or pot iallyic ser ious p rob lem o Figur 27w - 2, syst s, sprr ovid in g as m e ent r ealist pict ur e nofet twor he krealw or ld . nRef et werr or ing k ingagain en vir tonm ent se in hich assu m e t hat Host ial frand am eguisidaelines br oadcast . Bot h br idges f orw ar for d tm heance fr amwes pr of essionals oper A's at e.init Tools f or opt im izing syst em per ill end incrlessly, ease using allivav w or w id t help h and g the m t r ansm ission ot her ,pack s on b ot h pr odu ct it yailable an d imnet pr ov e keffband iciency, ingblockin t he r eader ake mor e in of t elligent costet - eff icient seg m en t s.for t h eir net w ork s. decisions A t opology w it h loops, such as t hat show n in Figur e 27 - 2, can be u sefu l as w ell as p ot en t ially har m fu l. A loop im plies t he exist ence of m ult iple pat hs t h rou gh t he int er net w or k, and a n et w or k w it h mu lt iple pat h s fr om sour ce t o dest in at ion can incr ease ov er all n et wor k f ault t oler ance t hr ou gh im p rov ed t opological flex ibilit y .

Spanning-Tree Algorithm The spann in g- t ree algor it h m ( STA) w as developed by Digit al Equ ipm en t Corp orat ion , a k ey Et h er n et vend or , t o p r eserv e t h e benefit s of loop s w hile elim inat ing t h eir p rob lem s. Dig it al' s algor it hm su bseq uent ly w as r evised b y t he I EEE 802 comm it t ee an d w as p ublished in t h e I EEE 80 2. 1d specif icat ion. The Dig it al algor it hm an d t he I EEE 8 02. 1d algor it hm are not com pat ib le. •

Table of Content s

•The STA desig I ndex nat es a loop - fr ee subset of t h e net w or k' s t opolog y by p lacing t hose b rid ge por t s It hat nt e rn or iv k ing chnologie sH ndbookin , Four iony ( blockin g) con dit ion. Blockin g b rid ge por t s can , et if wact e, Te w ould creat ealoops t o athstEdit andb be act iv at ed in t h e ev ent of a pr im ar y lin k failur e, pr ov iding a n ew pat h t hr ou gh t he By Cisco Systems, Inc. int er net w ork . lish er: Cisco Press ThePub STA uses a conclusion fr om gr aph t h eor y as a basis f or const ru ct in g a loop- f r ee sub set of t he Pub Sepolog tem ber 1, aph 2 003 t heor y st at es t he f ollow in g: net w or Dat k' se:t op y. 1Gr I SBN: 1- 58 705 -1 19 -2

For any conn ect ed gr aph consist in g of n odes and edges conn ect ing pair s of nod es, a Pages: 11 28 spann ing t r ee of edg es maint ain s t he con nect iv it y of t he gr aph but cont ains no loop s. Figur e 27 - 3 illust r at es how t he STA elim inat es loops. The STA calls for each b r id ge t o be assig ned a un iq ue ident if ier . Ty pically, t his ident if ier is on e of t he b r id ge's Media Access Con t r ol ( MAC) ad dr esses, plus an adm inist r at iv ely assig ned pr iorit y . Each por t in ev er y b rid ge also is The pdataedunedit ion of tifhe selling one, w net w ork r ef erence p rov ides add cover ageFin of ally , assiguned iq ue ident ierb (est wit- h in t hatallb rinid ge) hich is ing t yp ically it s ow n MAC ress. essent ial an d cu t t ingedg e t ech nologies. each b ridg e por t is associat ed w it h a p at h cost , w h ich r ep r esent s t h e cost of t r ansm it t in g a f ram e ont o a LAN t h rou gh t hat por t . I n Figur e 27 - 3, p at h cost s ar e n ot ed on t he lin es em anat ing f r om each Con b ridg e. Pat h vcost u su ally ed tbut bewor assig ned m an ually or kels, f rom cise ov er iewss ar ofet echn ologdefault ies essen ial tcan o n et k ing pr ofession alsbyatnet allwlev adm inist r at or s. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Figu r e 2e 7of-3cut. tSTABase d ologies Br i dgelikse Use De siwor gna te d a nstdor Root Por t s t o Cov erag ing edge t echn opt ical n et k ing and age Eli m in at e Loops Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

The f ir st act ivit y in spann ing- t r ee comp ut at ion is t he select ion of t he r oot b ridge, w hich is t he br idg e w it h t h e low est - v alue b rid ge ident if ier . I n Figur e 27 - 3, t h e r oot b ridg e is Br idge 1 . Next , t he r oot p ort on all ot her br idges is d et er m in ed . A br id ge's r oot por t is t he por t t hr oug h w h ich t he root br idg e can b e reached w it h t h e least aggr egat e p at h cost , a v alu e t hat is called t he r oot pat h cost . •

Table of Content s

Finally, d esign at ed b rid ges and t heir designat ed por t s ar e det er m in ed . A d esign at ed b ridg e is • I ndex t he br idge on each LAN t hat pr ov ides t he m inim um root pat h cost . A LAN's design at ed br idge is I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion t he only br idge allow ed t o f or war d fr am es t o an d fr om t h e LAN f or w hich it is t h e desig nat ed By Cisco br idg e. Systems, A LAN' s Inc. design at ed por t is t he por t t hat connect s it t o t he design at ed b rid ge. I n som e er: cases, w o or m or e br idges can hav e t he sam e r oot pat h cost . I n Figur e 27 - 3, f or Pub lish Cisco tPress exam ple, Br idges 4 and 5 can bot h r each Br id ge 1 ( t he root br idg e) w it h a pat h cost of 10 . I n Pub Dat e: Sep tem ber 1 1, 2 003 t his case, t he b r id ge ident if ier s ar e u sed again, t his t im e t o d et er m ine t h e desig nat ed br id ges. I SBN: 1- 58 705 -1 19 -2 Br idge 4 's LAN V por t is select ed over Br idge 5 's LAN V por t . Pages: 11 28

Using t h is pr ocess, all bu t on e of t he b rid ges dir ect ly conn ect ed t o each LAN ar e elim inat ed , t her eby r em ov ing all t w o- LAN loops. The STA also elim inat es loops in volv ing m or e t han t w o LANs, w hile st ill pr eser v ing con nect iv it y . Figur e 27 - 4 sh ows t he r esu lt s of apply ing t he STA t o t he net w ork sh own in Figur e 27 - 3. Figur e 27 - 4 sh ows t he t r ee t opolog y mor e clearly . I t also show t h atedt hedit e STA placed h Br idge 3 one an d net Bridg e 5' s por s t o LAN V in st andb m ode. The uspdat ion has of t he b est -bot selling all- inw ork ing r efterence p rov ides covery age of essent ial an d cu t t ing- edg e t ech nologies. ConFigu cise ovr er s of t echn olog ies essen n et worogy k ing an pr ofession als at all lev els, e v2iew 7 -4 . A LoopFr ee Trt ial e et oTopol d an STABase d f rom nov ice t o ex pert . Tr an spar e nt -B r idge N et w or k New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The sp anning - t r ee calculat ion occur s w h en t he br idge is p ow er ed up and w henever a t opology chang e is det ect ed . The calculat ion r equ ir es com mu nicat ion b et w een t he spann ing- t r ee br idg es, w hich is accom plished t h r ough conf igur at ion m essages ( som et im es called br idge pr ot ocol dat a un it s, or BPDUs) . Config ur at ion m essag es con t ain in for m at ion ident if y in g t he br idg e t hat is

pr esu m ed t o be t h e r oot ( r oot id en t ifier) and t h e dist ance fr om t he sen ding br idg e t o t h e r oot br idg e ( r oot pat h cost ) . Config ur at ion m essag es also con t ain t h e br idg e and por t id en t ifier of t he sen ding br idg e, as w ell as t he ag e of infor m at ion con t ained in t h e con figu rat ion m essage. Br idges exchan ge conf igur at ion m essages at regu lar int erv als ( t y pically 1 t o 4 second s) . I f a br idg e fails ( causing a t op ology chang e) , neighb orin g b rid ges w ill det ect t he lack of conf ig ur at ion m essages and w ill init iat e a spann in g- t r ee r ecalculat ion. •

Table of Content s All t r anspar ent - b rid ge t opolog y decisions ar e m ade locally by each br idge. Br idges ex ch ange •conf ig ur at ionI ndex messag es w it h n eigh bor ing br idges, and no cen t r al aut h orit y ex ist s t o d et er m ine Inet nt ew rnor et k w or k ing Tey chnologie H a ndbook , Four th Edit ion t opolog or admsinist r at ion. By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Frame Format Tr anspar ent b r id ges exchan ge conf igur at ion m essages an d t opology - ch ange m essages. Con figu rat ion m essages ar e sent b et ween br idges t o est ablish a net w or k t op olog y. Topology chang e m essages ar e sen t af t er a t op olog y chang e has b een det ect ed t o in dicat e t hat t he STA •should be r erTable of Content s br idges t o r elear n t h e locat ion of h ost s becau se a host may un. This for ces •or iginally havI ndex e been accessed fr om por t 1, alt h ough af t er t he t op ology chang e it m ay b e reached It hr nt eou rn et k ing ghw or por t 2 Te . chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figur e 27 - 5 illust r at es t he I EEE 802 .1 d con figu rat ion - m essage f orm at . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Figu r e 2 7 -5 . Tw el ve Fie lds Com pr i se t h e Tr an spar e nt -B r idge Con f igu r at ion M e ssag e

Pages: 11 28

[ View full size im age]

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . The f ield s of t he t ran sp arent br idg e con figu rat ion m essage are as follow s: New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP P rot ocol I de nt if ie r— Cont ains t he v alue zer o. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age V e rsion— Cont ains t he v alue zer o. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Me ssa ge Ty pe — Cont ains t he v alue zer o. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Fla g— Cont ains 1 b yt e, of wh ich only 2 b it s are used . The t opology - ch ange ( TC) least t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing signif icant bit sig nals a t opology chan ge. The t op ology - ch ange ack now ledgm ent ( TCA) most indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . signif icant bit is set t o ack now ledge r eceipt of a conf igur at ion m essage w it h t he TC b it set . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, h is a com anidge d u p-by t o-list d atinegr it efser2ence t he itt yopf ollow ics t hat t ial Root It D — book I d en tis ifies t he plet r oote br by t et op rior ed are by itessen s 6 - by t e tIoD.all net w or kin g p rof essionals, r egar dless of ex pert ise. Root Pa t h Cost — Cont ains t he cost of t h e pat h f rom t he b ridg e sen ding t he con figu rat ion Reader w ill obt g reatbreridg une.der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e m sessage t oain t hea root har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad ang eI D— of int sy stt he empsr and in clud descr s, rev iew quest ions Brirdge I degr en tal ifies ior it yserv an dices, I D of t he ing b riddet ge ailed sending t h ipt e mion essage. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e isI D— alsoI dext edt he n otponly t o new n et twor ing concep t s,mbut also t oasold er ,t .legacy P ort enend t ifies or t f rom w hich h e kconfigu r at ion essag ew sen This f ield syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in w hich allow s loops cr eat ed by m ult ip le at t ached b rid ges t o b e det ect ed and han dled. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease —ov Specif ies t h e am ount e sin ce t he rmor oot esent t he con, figur ion m essage pr oduMe ct ivssa it y ge an dAge im pr e eff iciency, help ing of t het im r eader m ake in t elligent cost -ateff icient on wfor hicht hteir h e net cur w r en t s. conf ig ur at ion message is based. decisions ork Ma x im um Age — I n dicat es wh en t h e cur rent conf ig ur at ion messag e should be d elet ed. H e llo Tim e — Prov ides t h e t ime period bet w een r oot br id ge conf igur at ion m essages. Forw ar d De l ay — Prov ides t h e len gt h of t ime t hat br idges should w ait b ef or e t r ansit ioning

t o a new st at e aft er a t opology chan ge. I f a br idg e t r ansit ions t oo soon , not all net w or k link s m ight be r eady t o ch ange t heir st at e, and loops can result . Topology - chan ge m essages consist of only 4 b yt es. These include a Pr ot ocol- I dent if ier field, w hich con t ains t h e valu e zer o; a Version f ield , w hich con t ain s t he value zer o; and a MessageTy pe f ield, wh ich cont ains t he v alue 1 28. •

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•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What t hr ee f ram e t y pes d oes a t r anspar ent br id ge f lood?

2:

How I dndex oes a br idg e lear n t he r elat ive locat ion of a w or k st at ion ?

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : Systems, What t wInc. o br id ge By Cisco

PDUs d oes a t r anspar ent br id ge g en er at e, and w hat ar e t hey u sed

for ? Pub lish er: Cisco Press

4:

What is t h e diff er ence bet w een f or war din g an d flooding ?

Pub Dat e: Sep tem ber 1 1, 2 003

5:

I SBN: 1- 58 -1 19 -2 Aft er b 705 r id ges det erm ine

t he span ning- t ree t op olog y, t hey w ill t ak e on var ious r oles por t s in t o v ar iou s m odes. Specif ically , t he roles ar e r oot an d d esign at ed br idg es, an d t h e m odes ar e desig nat ed por t s and r oot por t s. I f t here are 1 0 br id ges and 11 segm en t s, how man y of each ar e t her e in t he b road cast dom ain?

Pages: 28 ig ur e and11conf

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Clark , Kenn ed y, and Kev in Hamilt on . CCI E Pr ofessional Develop m en t : Cisco LAN Sw it ching . I ndian apolis: Cisco Pr ess, 19 99. •

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•

I ndex

•I nt Per lmwan, Rad I n t erconn ions, Second e rn et or k ing Teia. chnologie s H aect ndbook , Four th EditEdit ion ion : Br id ges, Rout ers, Sw it ches, and I n t ern et w or k in g Pr ot ocols. Bost on: Add ison Wesley , 19 99. By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 28. Mixed-Media Bridging Obj e ct i ve s • •

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Under st and br idging in a m ix ed Et hern et and Tok en Rin g env ir onm en t . I ndex

I nt e rn Descr et w or kibe ing Te chnologie sH a ndbook Foursour th Edit ion t he dif fer en ces b et w ,een cerou t e

t r anspar ent and t r anslat ion al br idg in g.

By Cisco Systems, Inc.

List som e of t h e ch alleng es of t r anslat ion al br idg in g. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background Tr anspar ent b r id ges ar e fou nd pr edom in ant ly in Et h er net net w ork s, and sour ce- rou t e br idges ( SRBs) are f oun d alm ost ex clu siv ely in Tok en Rin g net w ork s. Bot h t r anspar ent b r id ges and SRBs ar e pop ular, so it is r easonable t o ask w het her a m et hod ex ist s t o dir ect ly b r id ge bet w een t h em . •Sever al solutTable ofave Content s ions h ev olved. •

I ndex

ITr ntanslat e rn et wional or k ingbTe chnologie a ndbook , Four ridg ing pr sovH id es a r elat ivthelyEdit inion ex pensiv e solu t ion t o som e of t he m any pr oblems inv olved w it h b r id ging bet w een t r anspar ent br idging an d SRB dom ains. Tr anslat ional br idging By Cisco Systems, Inc. fir st ap peared in t he m id- t o lat e- 19 80s but has n ot b een ch am pioned b y any st an dar ds or ganizat ion . As a r esult , m any asp ect s of t r anslat ional br id ging ar e left t o t h e imp lem ent or . Pub lish er: Cisco Press

Pub 0, DatIe:BM Sepaddr tem ber 1 1, 2 003 I n 199 essed som e of t h e w eak nesses of t r anslat ional br idging by in t r oducing sour ceI SBN: 158 705 -1 19 -2 br idgin g. SRT br idges can for w ar d t raf fic f r om bot h t r anspar ent and r out e t r an sp arent ( SRT) sour cePages: r out e 11 28 en d n odes and can for m a com m on sp annin g t r ee w it h t r anspar en t b rid ges, t hereby allow in g en d st at ions of each t y pe t o com m un icat e w it h end st at ions of t h e same t yp e in a net w or k of ar bit r ary t opology . SRT is specif ied in t he I EEE 8 02. 1 d Ap pendix C.

Ult im at ely , t he g oal of connect ing t r anspar ent b r id ging and SRB dom ains is t o allow com mu nicat ion b et w een t ran sp arent br idg es an d SRB end st at ions. Th is ch apt er descr ibes t h e The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t echnical pr oblem s t hat m ust b e add ressed by alg orit h ms at t emp t ing t o d o t h is and pr esent s t w o essent ial an d cu t t ing- edg e t ech nologies. possible solu t ions: t r an slat ional br idging an d SRT br idg in g. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Translation Challenges Man y ch alleng es are associat ed w it h allow ing end st at ions f r om t he Et her net / t r anspar ent br idg in g dom ain t o comm u nicat e w it h end st at ions f r om t he SRB/ Tok en Ring d omain : •

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I ncom pa t ibl e bi t or de ri ng— Alt hough b ot h Et her net an d Tok en Ring supp ort 48 - bit I ndex Access Cont r ol dr esses, t he int er nal har dw ar e r ep resen t at ion of t hese I nt e rn Media et w or k ing Te chnologie s H(aMAC) ndbookad , Four th Edit ion add resses d iff er s. I n a ser ial b it st r eam repr esen t ing an ad dr ess, Tok en Ring con sid er s t h e By Cisco Systems, Inc. fir st b it encoun t er ed t o be t he h ig h- or der bit of a b yt e. Et her net , on t he ot her hand , considers t he f ir st bit encoun t er ed t o b e t he low - or der b it . The Et hern et f orm at is ref er r ed Pub lish er: Cisco Press t o as canonical f orm at , an d t he Tok en Rin g met h od is n oncanonical. To t ran slat e bet w een Pub Dat e: Sep tem 1, 2 003 canonical anber d n1oncanonical f orm at s, t he t r anslat ional b rid ge r ever ses t h e bit ord er for each I SBN: 158 705 -1 19 -2 by t e of t h e addr ess. For ex am ple, an Et her net ad dr ess of 0 C- 00 - 01- 38- 7 3- 0B ( canonical) tPages: r anslat 11es 28 t o an add r ess of 30 - 00- 80- 1 C- CE- D0 ( noncanon ical) for Tok en Ring. •

Em be dde d MAC a dd re sse s— I n som e cases, MAC add resses act ually ar e car ried in t he dat a por t ion of a f ram e. Th e Addr ess Resolut ion Pr ot ocol ( ARP) , a p opular p rot ocol in Tr ansm ission Cont r ol Pr ot ocol/ I nt ern et Pr ot ocol ( TCP/ I P) net w or ks, f or exam ple, p laces har dw ar e ad dr esses in t h e dat a por t ion of a link lay er fr am e. Conv ersion of addr esses t h at The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of m ight or m ight not app ear in t h e dat a por t ion of a fr am e is dif ficult becau se t hese mu st be essent ial an d cu t t ing- edg e t ech nologies. han dled on a case- by - case b asis. I PX also em beds Lay er 2 ad dr esses in t h e dat a por t ion of som e fr am es. Tr anslat ional br idges should r esequ en ce t he bit or der of t hese em b ed ded add t oo. rot ocols r esp ond ttial o t he add resses em bedded rot ocol Con resses, cise ov er v iewMany s of tpechn olog ies essen t o nMAC et wor k ing pr ofession als atinallt he levpels, f rom rnov at her t h an in t he Lay er 2 h ead er s. Ther efor e, t he t r an slat ional br idge m u st r esequence ice t o ex pert . t hese by t es as w ell, or t he device w ill not be capab le of respond ing t o t h e corr ect MAC add Newress. chapt er s include cov erag e of im por t ant t opics like VoI P and EAP ICov ncom iblcut e m ax iedge m u mt echn t ra nsfe r unilik t e( MTU ) siz e s— Ring and eragpa e tof t ing ologies opt ical n et wor kToken ing and st or ageEt hern et supp ort dif fer en t m ax im u m fr am e sizes. Et her net 's MTU is appr ox imat ely 1 500 by t es, w hereas Aut hen Tok ored Rin by g f rCisco ames Sy can st ems, be m uch w or ldw lar ger. ide leader Because in net br idg w or esking are fnot or t capab he I n t le er nofetfr. am e fr ag ment at ion an d r eassem bly , pack et s t hat ex ceed t he MTU of a giv en n et wor k m u st be I n t erndretopp w ored k in. g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. H a ndl ing Mast of er fr am t hee t- er stm a ts,uscon bi tcep a ct t s,ion t echn s— ologies, Token Ring an dfrdevices am es include used int hr t oday ee f r' am s net e- w stork at uing s indu stbit rys: . Lear A, C, n how an d E. t o The incorpur porpose at e int of er t hnet esew bit or kin s isg ttoechn t ell olog t h e ies fr am ine's t o asour LAN/ ce WAN w het env her irt honm e ent . Com plet dest e inat w it hion new sawant d heu fpdat r ame ed( A chapt bit set er s) ,on copied secur tithye, fr stam or age, e ( C opt bit ical set )net , orwfoun or k indg,erscalabilit r or s in t he y, and speed, fr am e t(hEisbit book set )is . Because a com plet Etehern an detu pdoes t o- dnat otesup r ef er por ence t t h ese t o t he b it s, t opt he ics qu t hat estare ion essen of howt ial t o t deal o all net w or w kin it h gt hem p rof essionals, is left t o t hreegar Et hdless er net -of Tok exen pert Ring ise. br idge m an ufact ur er . Reader H as ndl w illing obt of aineaxclu g reat si ve er un Toke dernst Ri anng dingfun ofctLAN i ons— and Cert WAN ain n et Tok w or enk ing, Rin gp barittsicu hav larelyno the corollar y har dwinarEt e,her pr ot net ocols, . For and ex amp serle, v ices Et her invnet olv ed h as . Fu nondam pr iorent it y al m echanism t ech nology , winf hereas or matTok ion en is pr Ring ov ided does. on a b r oad Ot hrer ang Token e of int Ring egr al bitsy s tsthat emmu s and st be serv t hrices, ow n in ouclud t w ing hen det a Tok ailed en descr Ring ipt fr am iones,isrev conv iewerquest t ed t oions an t o en su Et hreercon n etcept fr amcomp e include r eh ent he siont ok and en rbet it ,ent he t ion, mon and it oradbit dit, ional an d trhe esou r eser r cesvat f or ionfubrtither s. st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy H as,ndl ing of fr am ic e s— sp arent br idg eslddo otorinh er ent ly uonm nder st sand hat t o syst em pr ovid in geaxp mlore or e rr ealist pictTran ur e of t he realw or n etnw k ing en vir ent in w hich do w it h SRB ames. ansparfent br id lear n abou t t hfor em net w or k' y pr of essionals oper exp at e.lorer Toolsf r and guTr id elines or opt imges izing syst em per ance wsillt opolog incr ease hrivou ofet eff h e iciency, sour ce ad dr ing ess tof ingmfake ram es. hav e no, cost k now ledicient ge of t h e pr odutct it yghananalysis d im pr ov help heinr com eader morThey e in t elligent - eff SRB for routthe-eir discov decisions net wery ork pr s. ocess. H a ndl ing of rou t ing i nfor m at i on f ie ld ( R I F) inf orm a t ion w it h in Tok en Ri ng fr am e s— The SRB algor it hm places r out in g in for m at ion in t h e RI F field. Th e t r anspar ent - br idg in g algor it hm h as no RI F equiv alen t , and t h e idea of placing r out ing inf orm at ion in a f ram e is for eign t o t ran sp arent br idg in g.

I ncom pa t ibl e spa nni ng- t re e a lgor it h m s— Tran sp arent br idg in g and SRB b ot h use t he spann ing- t r ee algor it hm t o t r y t o avoid loops, bu t t he par t icular algor it hm s em ploy ed by t he t w o br idg in g met h ods ar e incom pat ible.

• •

H a ndl ing of fr am e s w it h out r out e i nfor m at i on— SRBs exp ect all int er - LAN f r ames t o cont ain r out e inf or mat ion . When a f r ame wit h out a RI F f ield ( includin g t r an sp arent br idgin g conf ig ur at ion and t opology - chang e m essages, as w ell as MAC fr am es sent f rom t he t r anspar ent - b ridg ing dom ain) arr iv es at an SRB br id ge, it is ig nor ed . Table of Content s I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Translational Bridging Becau se t here has been no r eal st and ard izat ion in how com m un icat ion bet w een t w o media t y pes should occu r , no sing le t r anslat ional br idg ing imp lem ent at ion can b e called cor r ect . This sect ion descr ibes sever al pop ular m et hods for im plem en t ing t r anslat ion al br idg in g. •

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•Tr anslat ionalI ndex b ridg es reor der sour ce and dest inat ion addr ess bit s w hen t r anslat ing bet w een IEt ntheer rn n etet w or k ingTok Te chnologie a ndbook Edit ion and en Rin gsf Hr ame for ,mFour at s.th The pr ob lem of em bedded MAC addr esses can be solved by p r ogr amm ing t h e br idge t o check for v ar ious t y pes of MAC add r esses, b ut t his solut ion mu st By Cisco Systems, Inc. be ad apt ed w it h each new t y pe of em bedded MAC addr ess. Som e t ran slat ional- b rid ging solut ions sim ply check for t h e m ost pop ular em bedded addr esses. I f t r anslat ion al- br idging Pub lish er: Cisco Press soft w ar e r un s in a m ult ipr ot ocol r out er , t he rou t er can successfu lly r out e t hese pr ot ocols and Pub Dat e: Sep tem ber 1 1, 2 003 av oid t h e pr oblem ent ir ely . I SBN: 1- 58 705 -1 19 -2

The RIPages: F field 11h 28as a sub field t h at in dicat es t he lar gest fr am e size t hat can b e accept ed by a par t icular SRB imp lem ent at ion . Tr anslat ion al br idg es t hat send f ram es fr om t he t r anspar ent br idg in g dom ain t o t he SRB dom ain usually set t h e MTU size field t o 15 00 by t es t o lim it t h e size of Tok en Rin g f r ames ent er ing t he t ran sp arent - br idging dom ain. Some host s cannot corr ect ly pr ocess t his field, in w hich case t r anslat ional b r id ges ar e for ced t o dr op t hose f ram es t hat exceed Et h erunpdat et ' s ed MTU size. The edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Bit s r epr esent ing Tok en Rin g fun ct ion s t hat hav e no Et h er net cor ollar y t y pically ar e t h row n out by t ran slat ion al br idges. For exam ple, Tok en Ring' s pr ior it y, reser v at ion, an d m on it or bit s ( cont ained in ov t heeraccesst r ol olog by t e) e d iscar Tok enk ing Ring' fr am e stals at us bit slev ( cont Con cise v iew s ofcon t echn iesaressen t ialded. t o n et wor prsofession at all els, ained f rom in t henov b ytice e follow in g t he endin g d elim it er, wh ich f ollow s t h e dat a field) are t reat ed diff er ent ly t o ex pert . depend in g on t he br idg e m anuf act u r er . Som e b ridg e m anuf act ur er s sim ply ign ore t he bit s. Ot h erNew s h ave t heerbrsidg e set cov t he erag C bite (of t o im in dicat e t hat t he like fr amVoI e has b een cop ied ) b ut n ot t h e A chapt include por t ant t opics P and EAP bit ( w hich in dicat es t hat t he dest inat ion st at ion r ecognizes t he addr ess) . I n t he for m er case, a Tok enCov Rinerag g sour e of cecut nod t ing e det edge ermt ines echn w ologies het h erlikt he e opt f ram ical en it etsent wor khas ing becom and steorlost age. Pr opon en t s of t his ap pr oach sug gest t h at r eliab ilit y m echanism s, su ch as t h e t r acking of lost f r ames, ar e bet t er Aut ored en byt at Cisco SyLay st ems, ide leader w or king left for imh plem ion in er 4 wofort ldw he OSI m odel.inPrnet oponent s off or sett the ingI nt ht er e nCetb.it cont end t h at t his b it m ust be set t o t r ack lost fr am es but t hat t he A bit can not be set because t he br idge is n ot n t ern et wdest or k in tI he final ingatTech ion. nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. he t cr er eat m s,e con cepwtar s, et echn ologies, an d devices t oday netSRB w orken ing Tr anslat ional bMast ridger es tcan a soft g at ew ay b et ween t he t w oused domin ains. To' st he d indu st ry . tLear how tion o incor athas e intaerrnet or kin g t an echn ies innum t o aber LAN/ WAN env ir onm st at ions, he tn r anslat al br por idg e in gwnum ber d aolog br idge associat ed w it h itent , so. it Comsplet new danSRB. d u pdat erber s on, in secur y , st oract age, optr ical net or ken intg, y, look lik e aw it sthandar Th eedrinchapt g n um t hisitcase, u ally eflect sw t he ir escalabilit t ran sp arent and t hain is book pletent e an u pt o- ddom at e ain, r ef ert ence t o t heional t op ics t hat essen br idgspeed, in g dom . To tis heat rcom anspar - bdrid ging he t r anslat b rid ge are is anot hert ial t o all w or kin g pbr rof essionals, r egar dless of ex pert ise. tnet r anspar ent idge. Reader s idgin w ill obt g reat er dun der st an LAN and n et wdom or k ain, ing, SRB p ar t icu ly t hion e is When br g f ain r omat he SRB omain t o ding t he t of r anspar ent - WAN b rid ging inflar or mat har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov idedt he on r em ov ed. RI Fs usually ar e cached f or u se b y subsequent r et u r n t r af fic. When br idgin g f r om a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t r anspar ent br idging t o t he SRB dom ain, t he t r anslat ional br id ge can ch eck t h e fr am e t o see if it thas o enasu con cept comp sion and rhas et enat ion, r esou r ces f orion fu, rtither st udyin. t o t h e unreicast dest in at ionr eh . I fent he f r ame mu ltand icastadorditbrional oadcast d est inat is sent Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy SRB dom ain as a spann ing- t r ee exp lorer . I f t he f r ame has a unicast add r ess, t he t ran slat ion al syst em s, pr ovid g adest m or e rion ealist pict of t he Irealet wd, or kiting en vir, onm in Fw hich br idg e looks u p in t he inat in ict he RIurFecache. f a pw ator h ld is nfoun is used and ent t h es RI pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease inf orm at ion is add ed t o t he f r ame; ot herw ise, t he f r am e is sent as a sp annin g- t r ee ex plor er. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions Figur e 28 -for 1 sh t hows eir net a mwix orkofs.Tok en Ring an d Et her net , w it h a t r anslat ional b r id ge int er connect ing t he Token Ring t o t he Et hern et . A u nicast t r ansfer sour ced by st at ion 1 on t he Tok en Ring t o st at ion 2 on t h e Et h er net segm ent passes t h r ough t w o b r id ges. St at ion 1 g en er at es a fr am e w it h a RI F t hat list s Ring1 - Bridg e1 - Ring 2- Br idge2- Rin g3 as t h e pat h. Not e t hat Ring 3 is really t he Et h er n et seg ment . St at ion 1 d oes not k now t hat St at ion 2 is on Et her net . When st at ion 2 r espon ds t o st at ion 1, it generat es a fr am e w it hout a RI F. Bridg e 2, t he t r anslat ional b r id ge,

not ices t he d est inat ion MAC add r ess ( st at ion 1) , in ser t s a RI F in t he f ram e, and f orw ar ds it t ow ar d st at ion 1.

Figu r e 2 8 -1 . A N et w or k t o De m onst r a t e a Un icast Tr a n sf er Be t w ee n a Tok en Rin g a nd a n Et he r ne t - At t a che d St at i on •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Becau se t he t w o sp anning - t r ee im p lem ent at ions ar e n ot com pat ible, m ult iple p at hs b et ween t he SRB and t he t ran sp arent - br idging dom ains t yp ically ar e not per m it t ed . Figur es 28- 2 t hr ough 28 Con ov er v iew serof t echn olog iest essen t ial t in o nt et wor k ing prbofession 4 illust r atcise e f ram e conv sions t hat can ak e place r anslat ional ridg ing.als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Figu r e 2 8 -2 . Four Fi el ds Re m ai n t h e Sa m e in Fr am e Conv er sion Be t w ee n I EEE 8 0 2 .3 an d Tok e n Ri ng

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Figu r e 2 8 -4 . Four Fi el ds Re m ai n t h e Sa m e in Fr am e Conv er sion t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . t w ee Eted h er et Typ e I In et0wor x8 k0ing D5concep For m t analso d Tok e er n , Rin g Cov erag eBe is also extnend n otn only t o new t s,a but t o old legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figur e 28 - 2 illust r at es t he fr am e con ver sion b et w een I EEE 802 .3 and Tok en Ring. Th e dest inat ion and sour ce addr esses ( DASA) , ser vice- access point ( SAP) , Logical Link Cont r ol ( LLC) inf orm at ion, and dat a ar e passed t o t he cor respond ing fields of t he dest in at ion f r ame. Th e dest inat ion and sour ce addr ess bit s ar e r eor der ed. Wh en br idg ing fr om I EEE 8 02. 3 t o Token Ring , t he leng t h field of t h e I EEE 80 2. 3 fr am e is r em ov ed. Wh en br idg in g fr om Tok en Rin g t o I• EEE 8 02. 3, tTable he accesscont r ol by t e an d t he RI F ar e r emov ed. Th e RI F can be cach ed in t he of Content s t r anslat ional b rid ge f or use by r et ur n t r aff ic. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Figur e 28 - 3 illust r at es t he fr am e con ver sion b et w een Et her net Ty pe I I an d Tok en Ring By Cisco Systems, Inc. Prot ocol ( SNAP) . ( SNAP add s v en dor an d t y pe cod es t o t h e Dat a field of t h e Sub net w ork Access Tok en Rin g f r ame. ) Th e dest inat ion and sour ce addr esses, t y pe inf orm at ion, and dat a ar e passed t o t Pub he lish corer: respond ing fields of t h e dest in at ion f r ame, an d t he DASA bit s ar e r eord er ed. W hen Cisco Press br idg in g fr om Tok en1Rin g SNAP t o Et her net Ty pe I I , t h e RI F inf orm at ion, SAP, LLC in for m at ion, Pub Dat e: Sep tem ber 1, 2 003 and v en dor code are r em oved. The RI F can be cached in t h e t r anslat ional b ridg e for use by I SBN: 1- 58 705 -1 19 -2 r et ur n t raf fic. Wh en br idg in g fr om Et hern et Ty pe I I t o Token Ring SNAP, no inf orm at ion is Pages: 11 28 r em ov ed.

Figu r e 2 8 -3 . Th r ee Fie lds Rem a in t he Sam e i n Fr a m e Con ve r si on The u pdat ed editBe iont w of ee t henb est in- one ork ing erence ides cover age of Et -hselling er n etall-Typ e I net I awnd Tokr efen Rin pgrov SNAP essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Figur e 28 - 4 illust r at es t he fr am e con ver sion b et w een Et her net Ty pe I I 0 x8 0D5 f orm at and Token I n t ern or k in Tech Hand Four t h Ed is haercom refer ence SAP, t hat LLC Ring . (etEtwhern etg Ty pe nologies I I 0x 80 D5 car book r ies I,BM SNA d atit aion in, Et n et pr fr ehensive am es. ) The DASA, enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w inf orm at ion, and dat a ar e passed t o t he cor respond ing fields of t he dest in at ion f r ame, anork d ting he tdest echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork80 ing inat ion and sour ce addr ess bit s ar e r eor der ed. Wh en br idg ing fr om Et hern et Ty pe I I 0x D5 indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent t o Token Ring , t he Ty pe and 80D 5 Header f ields are r em oved. When br idging f rom Token Ring. t o Com w iteh Inew anD5, d u pdat er oved. s on secur , st or age, opt icalinnet w or in g, scalabilit y, e Et h erplet n eteTyp I 0x 80 t he ed RI Fchapt is r em Th e it RIy F can be cached t he t r kanslat ion al br idg and speed, t h is book is a com plet e an d u pt od at e r ef er ence t o t he t op ics t hat are essen t ial t o all for use by r et ur n t r aff ic. net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Source-Route Transparent Bridging SRT br idges com bine im plem en t at ions of t h e t r anspar en t - br idg in g an d SRB algor it hm s. SRT br idg es u se t he r out in g in for m at ion in dicat or ( RI I ) b it t o dist in guish bet w een fr am es em p loy ing SRB and fr am es em p loy ing t r anspar ent br idging . I f t he RI I bit is 1 , a RI F is pr esent in t h e fr am e, •and t h e br idge Table of Content s alg or it hm . I f t he RI I bit is 0 , a RI F is not pr esent , an d t he br idg e u ses t h e SRB •uses t r ansparI ndex ent br id ging . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

As w it h Systems, t r anslat Inc. ional br idg es, SRT br idg es are n ot p er f ect solu t ion s t o t he p rob lem s of m ixedBy Cisco m ed ia br idg ing. SRT br idg es st ill m u st deal w it h t he Et her net / Tok en Ring incom pat ib ilit ies descr ibed earlier. SRT b rid ging is likely t o requ ire h ar dw are upg rad es t o SRBs t o allow t h em t o Pub lish er: Cisco Press han dle t he in cr eased bu rd en of an aly zing ever y pack et . Soft w ar e u pgr ades t o SRBs also m ight e: Sep tem ber 1 1, 2 003 be rPub equDat ir ed. Fur t h er m or e, in env ir onm en t s of m ixed SRT b r id ges, t r anspar en t b rid ges, and I SBN: 1- 58 705 es -1 19chosen -2 SRBs, sour ce r out m ust t r aver se wh at ever SRT br idges an d SRBs ar e available. Th e Pages: 11hs 28 p ot en t ially can be su bst ant ially inf er ior t o sp annin g- t r ee pat hs cr eat ed b y r esult in g p at t r anspar ent br idges. Fin ally , m ix ed SRB/ SRT br idg ing net w ork s lose t he benefit s of SRT br idg in g, so user s f eel com pelled t o ex ecu t e a com plet e cut ov er t o SRT b ridg ing at consider able exp en se. St ill, SRT br idg in g p er m it s t h e coex ist en ce of t wo incom pat ible env iron m en t s and allow s com m un icat ion bet w een SRB and t r anspar ent - b ridg ing en d nodes. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: • •

Tr anslat ional b ridg ing addr esses sever al issu es w h en int er connect ing diff erent m ed ia Table of as Content s net and Token Ring . List an d descr ibe f our of t he met h ods t y pes such Et h er descrI ndex ibed in t he chapt er .

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

2 : Systems, On e of Inc. t he By Cisco

challenges of t r anslat ional br id ging is t h e reor der in g of bit s w henev er a fr am e m ov es fr om an Et h er net t o a Token Ring segm en t . I f an Et her net st at ion t ar get s a Token Ring st at ion w it h a dest in at ion MAC ad dr ess of 0 0- 00 - 0C- 11- 2 2- 33 Pub lish er: Cisco Press ( canonical f or mat ) , w hat w ould t he MAC add ress look like on Tok en Ring Pub Dat e: Sep tem ber 1 1, 2 003 ( non can onical for m at ) ? I SBN: 1- 58 705 -1 19 -2

3 : Pages: Can11a28t ran slat ion al br idge w ork f or all Et her net and Tok en Ring net w ork s an d pr ot ocols? 4:

What is t h e diff er ence bet w een a sou r ce- r out e b rid ge and a sou r ce- r out e t r an sp arent br idg e?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Clark , Kenn ed y, and Kev in Hamilt on . CCI E Pr ofessional Develop m en t : Cisco LAN Sw it ching . I ndian apolis: Cisco Pr ess, 19 99. •

Table of Content s

•

I ndex

•I nt Per lmwan, Rad I n t erconn ions,, Four Secon d Edit e rn et or k ing Teia. chnologie s H aect ndbook th Edit ion ion : Br id ges, Rout er s, Swit ches, and I n t ern et w or k in g Pr ot ocols. Bost on: Add ison Wesley , 19 99. By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 29. Source-Route Bridging Obj e ct i ve s • •

Table of Content s

Descr ibe w h en t o use sour ce- r out e br id ging . I ndex

I nt e rn Under et w or k st ingand Te chnologie s Hen a ndbook Edit ion t he d if fer ce bet,wFour eenthSRB and

t r anspar en t b ridg ing.

By Cisco Systems, Inc.

Know t he m ech anism t hat end st at ions use t o specif y a sour ce- rou t e. Pub lish er: Cisco Press

Under st and t he b asics of sour ce- r out e fr am e for m at s.

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background The sou rce- r out e br idg ing ( SRB) alg orit h m w as dev elop ed by I BM and w as pr op osed t o t h e I EEE 80 2. 5 com m it t ee as t he means t o b ridg e bet w een all LANs. Sin ce it s in it ial pr oposal, I BM has off ered a n ew br idging st and ard t o t he I EEE 802 com mit t ee: t he sour ce- r out e t r anspar en t ( SRT) •br idg in g solut Table Content s ion . ofSRT br idging elimin at es pur e SRBs, p rop osin g t h at t he t w o t yp es of LAN •br idg es b e t r Ianspar ndex ent br id ges and SRT br idges. Alt hou gh SRT b r id ging has ach iev ed sup por t , ISRBs nt e rn et k ing chnologie s H aed ndbook th er Edit arweorst ill wTeidely deploy . SRT, Four is cov edionin Ch apt er 28 , " Mix ed- Media Brid ging. " This chapt erSystems, sum m arInc. izes t he basic SRB fr am e- for w ar ding algor it hm an d d escr ibes SRB f r ame field s. By Cisco Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SRB Algorithm SRBs ar e so nam ed because t hey assum e t hat t h e com p let e sour ce- t o- dest in at ion rou t e is placed in all int er - LAN f r ames sent by t he sou rce. SRBs st or e an d f or w ard t h e fr am es as indicat ed b y t he rou t e app ear ing in t he ap pr opr iat e fr am e f ield. Figur e 29 - 1 illust r at es a sam ple SRB net w or k. •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Figu r e 2 9 -1 . An SRB N et w or k Cont ai ns LANs a n d Br i dge s

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on I n Figur e 29 - 1, assum e t hat Host X w ant s t o sen d a fr am e t o Host Y. I nit ially, Host X d oes not a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions k now w h et h er Host Y r esid es on t h e same LAN or a dif fer en t LAN. To d et er m in e t his, Host X t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . sen ds ou t a t est fr am e. I f t hat fr am e ret u rn s t o Host X w it hou t a posit ive in dicat ion t h at Host Y Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy has seen it , Host X assum es t hat Host Y is on a r em ot e segm ent . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease To d et er m ine t h e ex act r em ot e locat ion of Host Y, Host X sends an ex plor er fr am e. Each br id ge pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient r eceivin g t h e exp lor er f ram e ( Br idg es 1 an d 2 , in t his exam p le) cop ies t he f ram e on t o all decisions for t h eir net w ork s. out b ound p ort s. Rout e inf or mat ion is ad ded t o t he ex plor er fr am es as t hey t r av el t hr oug h t he int er net w ork . W hen Host X's ex plor er f r am es r each Host Y, Host Y replies t o each indiv idually , using t he accum ulat ed r out e inf or mat ion . Upon r eceip t of all r esponse f ram es, Host X ch ooses a pat h b ased on som e p redet er min ed crit er ia. I n t he ex amp le in Figur e 29 - 1, t h is pr ocess w ill y ield t w o r out es:

LAN 1 t o Br idge 1 t o LAN 3 t o Br idge 3 t o LAN 2 LAN 1 t o Br idge 2 t o LAN 4 t o Br idge 4 t o LAN 2 Host X mu st select on e of t hese t w o r out es. The I EEE 802 . 5 specificat ion d oes not man dat e t h e crit er ia t h at Host X should use in ch oosin g a r out e, bu t it does m ake sev er al su ggest ions, includin g t h eTable follow • of ing: Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

First fr am e r eceiv ed

By Cisco Systems, Inc.

Response w it h t he m inim um num ber of h ops Pub lish er: Cisco Press

Response w it h t he lar gest allow ed f r ame size

Pub Dat e: Sep tem ber 1 1, 2 003

I SBN: 1- 58 705binat -1 19 -2ions of t he pr eced in g cr it eria Var ious com Pages: 11 28

I n most cases, t he p at h con t ained in t h e fir st f ram e r eceiv ed is used. Aft er a r out e is select ed, it is inser t ed int o fr am es d est ined for Host Y in t he for m of a r out ing infor m at ion f ield ( RI F) . A RI F is included only in t hose f ram es dest ined f or ot h er LANs. The pr esence of r out in g in for m at ion w it h in t h e fr am e is ind icat ed by set t ing t he m ost sign ificant bit The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of w it hin t he Sou rce Ad dr ess f ield, called t he r out ing inf or m at ion in dicat or ( RI I ) b it . essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Frame Format The I EEE 802 .5 RI F is st r uct u red as show n in Figur e 29 - 2.

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Table of Content s

Figu r e I ndex 2 9 -2 . An I EEE 8 0 2 .5 RI F I s Pr e se nt i n Fr a m es D est i ne d f or O t h er LAN s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag ing edge ical fields: n et worRout k inging andCon st or The RI F illu st reatof edcut in tFigur e 29 t- echn 2 conologies sist s oflik t weoopt main t r age ol and Rou t ing Desig nat or . Th ese f ields are d escr ib ed in t he su mm ar ies t hat follow . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Routing Field enables net Control w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu Rout st ry . ing LearCon n how t o incor er net w or kins:g Ty t echn a ,LAN/ envFram ir onme.ent . The t r ol field conpor sistats eofint f our sub field pe, olog Lengies t h,inDt oBit an d WAN Lar gest The Com plet w it hmnew an dinu tpdat chapt s :on secur it y , st or age, opt ical net w or k in g, scalabilit y, fields ar ee sum ar ized he f ed ollow ing er list and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Ty pe — Consist s of t hr ee possib le t y pes of rou t ing cont r ols: Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e - Sp ecif icaand ll y rout e d—inv Used w h. en t h e sou odenology sup plies t he r out in pr t he RI F on har dw ar e, pr ot ocols, ser v ices olv ed Fu ndam entrce al tnech inf or mat ione is ov ided header . The id st ges e t hserv e frices, am e in byclud usin g tdet he ailed r out e descr design ors,f ield( s) . quest ions a b r oad r ang e of int egr albrsy emr sout and ing iptat ion rev iew t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . l pa t hs xp lor — Used t o fin a r kem e n ode.t s,The t e is as t he Cov erag e is- Al also ext ende ed n oteronly t o new n etdwor ingotconcep butrou also t o collect old er , ed legacy am in e gt r av eror ses he n et . Br idges d t ow or t he num ber anwdhich t he syst em s, prfrovid am e rtealist icwor pictkur e of t he ad realld frnam et weort heir k ing br enidge vir onm ent s in r ing num berTools on t oand w h ich t he f r amf or e isopt forim w izing ar ded.syst ( Them e fir st for br idg e also add s tease he r ing pr of essionals oper at e. gu id elines per m ance w ill incr er pr ofov t he f irst rin g. ) help Th e ing t ar get est inatm ion w ill r eceive as man y fr am as pr odu ct iv it ynu anmb d im e eff iciency, t he dr eader ake mor e in t elligent , cost - effes icient es tnet o tw hat decisions forr out t h eir orkdest s. in at ion. - Sp ann in g- t r ee e x plor er — Used t o fin d a r em ot e n ode. On ly br idges in t he spann ing t r ee f or war d t he fr am e, adding t h eir b r id ge nu m ber and at t ached rin g nu mb er as it is f or war d ed . The span ning- t ree ex plor er r edu ces t h e num b er of f r ames sen t d ur ing t he d iscov er y pr ocess.

Le ng t h— I n dicat es t he t ot al len gt h ( in by t es) of t he RI F. The value can r ang e fr om 2 t o 30 by t es.

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D Bi t — I n dicat es and con t r ols t he d ir ect ion ( f or w ard or r ever se) t hat t he f r am e t r aver ses. The D b it aff ect s w het her br idges r ead t he r ing nu mb er / br idg e nu mb er com bin at ions in t he r out e d esign at ors fr om r ight t o lef t ( f or war d) or f r om lef t t o r ight ( r ev erse) . Table of Content s

La rg estI ndex Fr am e — I n dicat es t he lar gest f ram e size t hat can be han dled alon g a desig nat ed size, bu t b rid ges can low er it if t h ey can not accom m odat Cisco Systems, Inc.e t he r equest ed size.

I nt e rn retout w ore. k ing chnologie s Hially a ndbook ionf r ame TheTesou rce init set s, Four t he th larEdit gest By

Pub lish er: Cisco Press

Routing Pub Dat e: Designator Sep tem ber 1 1, 2 003 Fields I SBN: 1- 58 705 -1 19 -2

Each rPages: out ing11designat or field consist s of t w o sub field s: 28 Ri ng N um be r ( 1 2 bi t s) — Assigns a v alue t h at m ust be un ique w it h in t h e br idged net w or k. The uBri pdat ed N edit ion - selling all-ainone net ings rtef erence p rovbides cover ageber of dge um beof r (t4hebbitest s) — Assigns v alue t h atw ork f ollow he r ing num er . Th is num essentdoes ial an d cu t t ingedg e t ech nologies. n ot hav e t o be u nique unless it is p arallel w it h anot her b rid ge connect ing t w o r ing s. Br idges add t o t he f r ame t heir br idge num ber an d t h e r ing num ber on t o w hich t he f r ame is cise ov erf irvst iewb sr idofget echn iest he essen t o ber n et wor k ing for w arCon ded. ( The alsoolog ad ds rin gt ial n um of t he fir pr st ofession r ing. ) als at all lev els, f rom nov ice t o ex pert . Rou t es are alt er nat in g sequences of r ing and br idge n um ber s t hat st ar t and end w it h rin g chapt er sRI include cov terag e or of eim ante tropics VoI P and EAP. The I EEE sp ecifies a nu mbNew er s. A sin gle F can con ain m t hpor an ton out inglike designat or field m axim um of 14 r out ing designat or field s ( a m ax im um of 13 b ridg es or hop s becau se t he last Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age br idg e num ber alw ay s equals zer o) . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Unt il r ecent ly , I BM sp ecified a m ax imu m of eig ht rou t ing desig nat or f ield s ( a m ax imu m of sev en br idg es or hops) , an d most br idge m anu fact ur er s follow ed I BM' s im plem ent at ion . Newer I BM I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat br idg e sof t w ar e pr ogr am s com bined w it h new LAN ad apt ers su ppor t 13 hops. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: • •

Descr ibe a basic dif fer en ce b et ween t ran spar en t b ridg es and sou r ce- r out e b rid ges Content s din g p r ocesses. r elat Table iv e t ooft he f or war I ndex

I nt e 2 rn:et wRecall or k ing Te chnologie s H ast ndbook , Four th Edit t hat t he SRB and ard s do not ion sp ecify By

how a sou r ce select s a pat h t o t he dest inat ion w henever m ult iple ch oices exist . Th e ch apt er list ed f our m et hods t hat a Cisco Systems, Inc. sour ce cou ld u se t o m ak e t he d ecision an d said t hat t he f ir st r eceived fr am e ( pat h ) w as t h e most comm only u sed m et hod. W hat assum pt ion s m ight t he sour ce m ak e Pub lish er: Cisco Press abou t t h e net w or k w hen u sin g t his m et hod? Pub Dat e: Sep tem ber 1 1, 2 003

3:

I SBN: -2 How1- 58 d o705 st-1 at19 ions

an d br id ges k now if t h er e is a sou rce r out e defined in t he f ram e?

Pages: 11 28

4:

What pr oblem s m ight y ou an t icipat e in a larg e SRB net w ork wit h m any alt er nat e pat h s?

5:

Becau se only 4 bit s ar e used t o d ef ine br idg e num ber s, does t h is mean t hat t her e can 4 beed onedit ly 16 idges ) ? Wh y or hy net n otw ? ork ing r ef erence p rov ides cover age of The u pdat ionbrof t he b( 2est=- 16 selling allin- w one essent ial an d cu t t ing- edg e t ech nologies. 6 : Can y ou hav e a lar ge n um ber of br idges at t ach ed t o a cent r al r ing, all w it h t he sam e br idg e valu e? Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom 7 :novAice 1 2-t obit exvpert alu e. defin es r ing nu m bers. Can y ou hav e m or e t han 40 96 r in gs in t he net w or k ( 2 12 = 40 96) ? Why or wh y not ? New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Com put er Technology Resear ch Corp orat ion . The I BM Token Ring Net w or k . New Yor k : Pr ent ice Hall, 19 90. •

Table of Content s

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•I nt IeEEE. I EEE dar d for Local Area w orion k s: Tok en Ring Ph ysical Lay er Specif icat ion s. " June rn et w"or k ing St Tean chnologie s Ha ndbook , FourNet th Edit 19 89. By Cisco Systems, Inc.

• Alt Pub hlish ough er: Cisco n ot dir Press ect ly relat ed t o sour ce- r out e br d i ging , an ef for t t o d ef ine a high- sp eed Token RingPub stDat ande:ard f orber I EEE 02. 5 is und er w ay . Det ails m ay be m on it or ed at t h e Web sit e Sep tem 1 1, 28003 ht t p: / /Iw w w1. hst ra.-1 com SBN: 58 705 19 -2/ . Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 30. LAN Switching and VLANs Obj e ct i ve s • •

Table of Content s

Under st and t he r elat ion ship of LAN sw it ch ing t o legacy int er net w or king dev ices such as I ndex br idg es an d rou t er s.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Under Systems, st and Inc. t he

ad van t ages of VLANs.

Know t he d if fer en ce bet w een access and t r un k lin ks.

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

Know t he p ur pose of a t r un k pr ot ocol. I SBN: 1- 58 705 -1 19 -2

Under Pages: st 11and 28 Lay er 3 sw it ching concep t s. ALAN sw it ch is a dev ice t hat p r ovides m uch high er por t d en sit y at a low er cost t h an t rad it ion al br idg es. For t h is reason, LAN sw it ch es can accomm odat e net w or k desig ns f eat u rin g f ewer u ser s per segm en t , t h er eby incr easing t h e aver age av ailable ban dw idt h per u ser . This chap t er pr ov ides a sum m ar y of gener al LAN sw it ch operat ion an d m aps LAN sw it ching t o t he OSI The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of r ef erence m odel. essent ial an d cu t t ing- edg e t ech nologies. The t rend t ow ar d few er user s p er segm ent is kn ow n as m icr osegm ent at ion . Micr o- seg ment at ion allow sCon t hecise cr eat of psriv e or olog d ed icat segt ment at kis, e ofession user perals segatment . Each ov ion er v iew ofat t echn ies ed essen ial t o s—t n et hwor ingonpr all lev els, fuser rom r eceives inst an t access t o t he f ull b andw idt h an d d oes not hav e t o cont end f or av ailab le nov ice t o ex pert . ban dw idt h w it h ot her users. As a r esu lt , collisions ( a nor m al phenom enon in sh ar ed - mediu m net w or ks em ploy hu bs) do long t he eq uipm operat es in fu ll- d uplex m ode. New chapt ering s include covnot eragoccu e ofr,imas por t antast opics like VoIent P and EAP A LAN sw it ch f orw ar ds fr am es based on eit her t he f r ame' s Lay er 2 addr ess ( Lay er 2 LAN sw it ch ) or , in Cov somerag e cases, t het ing f ram e's Lay er ologies 3 ad dr ess ultical ilayner LANk sw ch) . st A or LAN e of cut edge t echn lik e( m opt et wor ingitand agesw it ch is also called a f r ame sw it ch becau se it for w ar ds Layer 2 f ram es, w her eas an ATM swit ch for w ar ds cells. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Figur e 30 - 1 illust r at es a LAN sw it ch p rov iding dedicat ed band wid t h t o dev ices an d illust r at es t he rI nelat t ern ion etsh w or ip kof in gLayer Tech 2 nologies LAN swHand it ching book t o ,t he Four OSI t h dat Ed itaion lin, kislayer a com . pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new pdat chapt Sw er s on secur y , Da st ortage, neter w or k invi g,ce scalabilit y, Figu r ean3d0u-1 . AedLAN it ch I sit a a Liopt nkical Lay De and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

History The ear liest LAN sw it ches w er e d ev elop ed in 19 90. Th ey w er e Lay er 2 dev ices ( br idg es) dedicat ed t o solving d esk t op band wid t h issues. Recent LAN swit ches ev olv ed t o m ult ilay er dev ices capable of h andling p rot ocol issues inv olved in h igh- b andw idt h ap plicat ion s t hat •hist or ically hav Table Content e bofeen solv sed by r out er s. Today , LAN sw it ches ar e used t o r eplace hub s in t he •w irin g closet I because ndex user app licat ions d em an d g reat er ban dw idt h . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

LAN Switch Operation LAN sw it ches ar e similar t o t r anspar ent br idges in fun ct ion s such as lear nin g t h e t opolog y, for w ar ding , and f ilt er ing. These sw it ches also supp ort sev er al new an d u nique feat ur es, su ch as dedicat ed com m unicat ion bet w een dev ices t hr ou gh full- d uplex oper at ions, m ult iple sim ult aneous •conv er sat ions, Table Content andof m edia- sr at e adap t ion. •

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IFullnt e rndup et wlex or k ing Tem chnologie s H abet ndbook , Four Edit com unicat ion w een netthw or k ion devices incr eases file- t r ansfer t hr ou ghp ut . Mu lt iple simu lt aneous conv ersat ions can occu r by for w ard ing, or sw it ching , sev er al pack et s at t h e same By Cisco Systems, Inc. t im e, t her eb y increasing net w or k cap acit y by t he num ber of conv ersat ions su ppor t ed. Fulldu plex com m un icat ion eff ect iv ely d oubles t he t hr ough put , w hile w it h m edia- r at e ad apt ion, t he Pub lish er: Cisco Press LAN sw it ch can t r an slat e b et w een 10 and 100 Mb ps, allow in g band wid t h t o be allocat ed as Pub Dat e: Sep tem ber 1 1, 2 003 needed. I SBN: 1- 58 705 -1 19 -2

DeployPages: ing LAN 11 28 sw it ches r eq uir es n o chan ge t o ex ist ing hub s, net w ork in t erf ace car ds ( NI Cs) , or cabling.

VLANs Defined The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent d in cued t t inge t ech nologies. A VLANialisan def as aedg br oadcast d om ain w it h in a sw it ched net w or k. Broad cast dom ains describe t he ex t ent t hat a n et w or k pr op agat es a b road cast fr am e gener at ed b y a st at ion. Some sw it ches m ay be conf igur ed t o sup por t a sin gle or m ult iple VLANs. Whenever a swit ch supp ort s m ult iple Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom VLANs, b road cast s w it h in one VLAN n ev er app ear in anot her VLAN. Sw it ch por t s conf ig ur ed as a nov ice t o ex pert . m em b er of on e VLAN belon g t o a diff er ent br oadcast d omain , as com par ed t o sw it ch por t s conf igNew ur edchapt as mer em of acov diferag fer enet of VLAN. s bers include im por t ant t opics like VoI P and EAP Cr eat Cov ing erag VLANs enab min ist r at or s t o build oadcast omains w it h st f ew er u ser s in each e of cut tles ingad edge t echn ologies lik e br opt ical n etdwor k ing and or age br oadcast d om ain . This in cr eases t h e ban dw idt h available t o user s becau se few er user s w ill cont end for t heby b andw h .st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Aut h ored CiscoidtSy Rou t eret sw also m gaint ainnologies br oad cast dom ain, isolat block b r oadcast fr amrefer es. Theref I n t ern or k in Tech Hand book Four tion h Edb ity ion , isinagcom pr ehensive ence tore, hat tenables r aff ic can p ass fr om one VLAN t o anot h er only t hr oug h a r out er . net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Nor each elong s at t o eaint difer fer enwt or VLAN. ore,ies a net k w itWAN h m any bnetent s w.ill indumally st ry . ,Lear n sub hownet t o bincor por net kin g tTheref echn olog in t ow aorLAN/ envsu ir onm pr obab ly hav e m any VLANs. Sw it ches and VLANs en able a n et wor k ad min ist r at or t o assig n ser s Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilituy, tand o brspeed, oadcastt hdom ains based up on t he user 's j ob need . This p rov ides a h igh lev el of deploy m en is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o tall flex ibilit y for a w or k adm inistdless rat or.of ex pert ise. net w or kin g p rofnet essionals, r egar Adv ant ag t heder f ollow : of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Reader s wes ill of obtVLANs ain a ginclude reat er un st aning ding har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Segm en t at ion of br oadcast dom ains t o cr eat e mor e b andw idt h t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag ext end ot only new n it ethwor k ing tconcep t s, ies but also t o old er , legacy Addeitis ionalso al secur it y ed b y nisolat in gt ou ser sw br idge echn olog syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals e.ibilit Tools and gu id elines or opt imrat izing emphper for mplacem ance went ill incr ease Deploy moper en t fat lex y based u pon job ff unct ion hersyst t han ysical pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Switch Port Modes Sw it ch p ort s ru n in eit her access or t ru nk m ode. I n access m ode, t he in t er f ace belon gs t o one and only on e VLAN. Nor m ally a sw it ch p ort in access mod e at t aches t o an end u ser d ev ice or a

ser v er. The f ram es t r ansm it t ed on an access link look like any ot her Et her net f ram e. Tr unk s, on t he ot her hand , m ult iplex t r aff ic for mu lt iple VLANs ov er t he sam e ph ysical link . Tr unk lin ks u su ally in t erconn ect sw it ches, as show n in Figur e 30 - 2. How ever , t h ey m ay also at t ach en d devices su ch as ser ver s t hat hav e special adapt er car ds t hat p ar t icipat e in t h e m ult iplexin g p rot ocol. • •

Table of Content s I ndex Figu r e 3 0 -2 . Sw i t ch e s I n t e r conn ect e d w it h Tr un k Li nk s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Not e t h at som e of t he d ev ices at t ach t o t heir sw it ch u sing access link s, w hile t he con nect ion s and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all bet w een t h e sw it ches u t ilize t ru nk link s. net w or kin g p rof essionals, r egar dless of ex pert ise. To m u lt ip lex VLAN t r aff ic, sp ecial p rot ocols ex ist t hat encapsulat e or t ag ( m ar k ) t h e fr am es so Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e t hat t he receiv ing dev ice k now s t o w hich VLAN t h e fr am e belong s. Tru nk pr ot ocols ar e eit her har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on pr opr iet ar y or based u pon I EEE 80 2. 1Q. For ex am ple, a p rop r iet ar y t r un k pr ot ocol m ay be lik e a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Cisco's p rop riet ar y I nt er - Sw it ch Lin k ( I SL) , w hich en ables Cisco dev ices t o mu lt iplex VLANs in a t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . m anner op t imized for Cisco com pon en t s. Or , an int er vend or solu t ion may b e im plem ent ed, su ch Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy as 8 02. 1Q, w hich enab les p rod uct s f rom mor e t han one v en dor t o m ult iplex VLANs on a t ru nk syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich link . pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu anlink d im ovlteiple eff iciency, helpsing t hebreeader m ake e intt elligent , cost - effbicient Wit houcttivt rituynk s,prmu access link m ust inst alled t o mor su ppor mu lt ip le VLANs et w een decisions for t h eir net w ork s. sw it ch es. Th is is not cost - eff ect iv e and d oes n ot scale w ell, so t ru nk s ar e pr eferab le for int er con nect in g sw it ches in most cases.

LAN Switching Forwarding

LAN sw it ches can be char act erized by t h e for w ar ding m et h od t hat t hey supp ort . I n t h e st or eand - for w ar d sw it ching m et hod, er r or check ing is per for m ed an d er r oneous f ram es ar e discard ed . Wit h t he cu t - t hr oug h sw it ching m et hod, lat ency is r educed by elim inat in g er r or check ing . Wit h t he st or e- and- for w ard sw it ching m et h od, t h e LAN sw it ch cop ies t he ent ir e fr am e int o it s onb oard b uff er s an d com pu t es t he cy clic r edun dancy check ( CRC) . The fr am e is discar d ed if it cont ains a CRC er r or or if it is a r unt ( less t han 6 4 b yt es, includ in g t he CRC) or a giant ( mor e t• han 1 518 byTable t es, including of Content s t h e CRC) . I f t he f ram e d oes not con t ain an y err or s, t he LAN sw it ch look s up t he d est inat ion ad dr ess in it s for w ar ding , or sw it ch ing, t able and det er min es t he • I ndex out g oing int erf ace. I t t hen w ar ds t h ethfr Edit am ion e t ow ar d it s dest in at ion. I nt e rn et w or k ing Te chnologie s Hfor a ndbook , Four By Systems, WitCisco h t he cu t - t hrInc. oug h

sw it ching m et hod, t he LAN sw it ch copies only t he dest in at ion ad dr ess ( t h e fir st 6 b yt es f ollow ing t h e pr eamb le) int o it s onboar d bu ffer s. I t t h en look s up t he dest in at ion lishin er: itCisco Press addPub ress s swit chin g t ab le, det er m ines t he out goin g int er f ace, an d f or war d s t he f r ame t ow ard it s dest inat A ber cut1-1, t hr ough sw it ch pr ov ides r ed uced lat ency because it b eg ins t o for w ar d t h e Pub Dat e: ion. Sep tem 2 003 fr am e Ias soon reads t he dest inat ion add ress and det er min es t he out g oing int erf ace. SBN: 1- 58as 705it -1 19 -2 Pages: 11 28

Som e sw it ch es can be conf igur ed t o p er for m cu t - t hr oug h sw it ching on a p er - por t basis unt il a user- defined er r or t h reshold is reached, w h en t h ey au t om at ically chan ge t o st or e- and - for w ar d m ode. Wh en t he er r or r at e f alls b elow t he t h reshold, t he p ort aut om at ically ch anges b ack t o st or e- an d- f orw ar d m ode. The usw pdat ed edit ionuse of tst heoreb est selling alloneiques net wtork r eft erence p rovsw ides cover LAN it ches m ust an- dfor w ar d int echn o suing ppor m ult ilayer it ch ing. age Th e of sw it ch essent aned tcu ingedg t echbefor nologies. m ust r ial eceiv het ten t ire fre ame e it p er f orm s an y pr ot ocol- layer op er at ions. For t h is reason, adv anced sw it ches t hat per for m Layer 3 sw it ch ing are st or e- and - for w ar d d ev ices. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

LAN Switching Bandwidth

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP LAN sw it ches also can be char act erized accor ding t o t he p rop or t ion of b andw idt h allocat ed t o em of et cut lik e opt n et k ing and agepor t , w hile each Cov p orterag . Sym rict ing sw itedge chingt echn pr ovologies ides evenly d istical r ibut edwor ban dw idt h t st o or each asym m et r ic sw it ching pr ov ides un lik e, or un eq ual, b andw idt h bet w een som e por t s. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . An asym m et r ic LAN sw it ch p r ovides sw it ched conn ect ions bet w een por t s of un lik e b andw idt h s, Isuch n t ernas et w k inbinat g Tech Handan book , Four t h EdThis it iont ,ypise aofcom ehensive refer ence10 t hat a or com ionnologies of 10 BaseT d 100 BaseT. sw itprchin g is also called / 100 enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork sw it ching . Asy mm et r ic swit chin g is op t im ized for client / serv er t r aff ic flow s in w hich m u lt ip leing tclient echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork s sim ult an eou sly com m unicat e w it h a serv er , r eq uir in g mor e b andw idt h dedicat ed t o t hing e indu st . Lear t o aincor at e int w ort kin ser v er rypor t t o nprhow event bot tpor leneck at er t hnet at por . g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and h isitbook a comsw plet e an conn d u p-ect t o-ions d at ebet r efw ereen encepor t ot st he ics sam t hat eare ial, such t o all A symspeed, m et r ict sw ch p r is ovides it ched w itthopt he banessen dw idtt h netall w or1kin g p rofor essionals, r egar dless as 0BaseT all 1 00BaseT. Sym mofetex r icpert sw itise. ching is op t imized for a r easonab ly dist rib ut ed t r aff ic load, such as in a p eer - t o- peer deskt op env iron m en t . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har ar e, pranag ot ocols, v ices ed . ed Fu ndam ent of al ban t echdw nology inf or mat ionion issprbet ovw ided A n dw et wor k m er mand ust ser ev alu at einv t heolv need am ount idt h for con nect een on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest dev ices t o accom m odat e t h e dat a flow of net w ork - based applicat ions w hen decid in g t o selections an tasym o en su rer ic conorcept r ehsw enitsion m et symcomp m et ric ch. and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

LAN Switch and the OSI Model LAN sw it ches can be cat egor ized accord ing t o t h e OSI lay er at w h ich t hey f ilt er an d f or w ard , or sw it ch , fr am es. These cat egor ies ar e: Lay er 2, Layer 2 w it h Lay er 3 feat ur es, or m ult ilayer . •A Layer 2 LAN Table Content s at ionally sim ilar t o a m ult ip ort br idge but has a m uch h igher sw itofch is oper •capacit y and I supp ndex ort s m any new f eat ur es, such as f ull- dup lex op er at ion. A Layer 2 LAN sw it ch Iper nt efor rn et k ing Tein chnologie s Herin a ndbook , Fouron th Edit mwsorsw it ch g and filt g b ased t heion OSI dat a lin k layer ( Layer 2 ) MAC add ress. As w it h br idg es, it is com p let ely t r anspar ent t o net w or k pr ot ocols and user app licat ions. By Cisco Systems, Inc.

A Layer 2 LAN sw it ch w it h Lay er 3 f eat ur es can m ak e swit chin g d ecision s based on m or e Pub lish er: Cisco Press inf orm at ion t han j ust t h e Lay er 2 MAC addr ess. Su ch a sw it ch m ig ht in corp orat e som e Layer 3 Dat e:t rol Sep tem 1, 2su 003ch as br oadcast and m ult icast t r aff ic m anagem ent , secu rit y t hr ough t r affPub ic- con featber ur 1es, I SBN: 158 705 -1 19 -2 access list s, and I P fr agm ent at ion . Pages: 11 28

A m u lt ilay er swit ch m akes sw it ching and filt er in g decisions b ased on OSI dat a link lay er ( Lay er 2) and OSI n et wor k lay er ( Lay er 3) addr esses. This t y pe of sw it ch dy nam ically decides w het her t o sw it ch ( Lay er 2) or r out e ( Layer 3 ) incom ing t r aff ic. A m ult ilayer LAN sw it ch sw it ch es wit h in a w or kg rou p and rou t es bet w een dif ferent w or kg rou ps. The u pdat editgion of tshe ba estflow - selling allin- one w ork r effrerence p rov ides cover age Lay er 3 swed it chin allow dat s t o by pass r outnet er s. Theing f irst am e passes t hr ough t h e rof out er essent ial an d cu t t ingedg e t ech nologies. as n orm al t o ensur e t hat all secu rit y p olicies ar e observ ed. Th e sw it ches w at ch t he w ay t hat t he r out er t r eat s t he fr am e and t hen r ep licat e t h e pr ocess f or subsequent fr am es. For ex am ple, if a ser iesCon of FTP flow s ft rechn om aolog 1 0.ies 0. 0. 1 t o t1ial 92.t o 16n8. 1, kt ing he f pr ram es nor m pass roufgh cise frovam er ves iew s of essen et1. wor ofession alsally at all levt hels, roma r out ernov . Mult ilay er sw it ching ob ser ves h ow t he rou t er ch anges t h e Lay er 2 and Lay er 3 h ead er s ice t o ex pert . and im it at es t he r out er f or t h e r est of t he f ram es. This r educes t he load on t he r ou t er and t he lat ency t hrchapt oug h er t he net w or kcov . erag e of im por t ant t opics like VoI P and EAP New s include Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: • •

A m u lt ilay er swit ch m imics t h e act ion s of a r out er w h en an init ial f ram e p asses Table of rContent t hr ou gh a out er . sWhat t h in gs d oes t he m ult ilayer sw it ch d o t o t he Layer 2 an d Layer I ndex s t o t h or ough ly im it at e t he r out er ? 3 header

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

2 : Systems, A LAN Inc. sw it ch By Cisco 3:

m ost closely r esem bles w hat t y pe of int er net w or king dev ice?

Tw o t r u nk pr ot ocols w ere d escr ibed. For w hat sit uat ion wou ld y ou use t h e I EEE 80 2. 1Q m ode?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 1- 58 705 -1 19 -2 g m et hod pr ot ect s net w or k seg ment ban dw idt h fr om er r ored fr am es? 4 : I SBN: Which swit chin Pages: 11 28

5:

How d oes a st or e- an d- f orw ar d sw it ch kn ow if a f r ame is er r or ed ?

6:

Do VLAN b ord er s cr oss r out ers?

: How d oes t r unk k -diff er fr om an one access link The u7 pdat ed edit iona of t he blin est selling all- innet w ork?ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. 8 : Befor e sw it ch es and VLANs, adm inist r at ors assign ed user s t o a net w or k based n ot on t he user ' s need s, but on somet hin g else. What det er m ined t he u ser n et w or k Con assig cise ov nm eren v iew t ? s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Br ey er , Robert , and Sean Riley . Sw it ch ed and Fast Et hern et . New Yor k : Zif f- Dav is Pr ess, 1 997. •

Table of Content s

•• Clark , Kenn ed y, and Kev in Hamilt on . CCI E Pr ofessional Develop m en t : Cisco LAN Sw it ching . I ndex II nt ndian apolis: Cisco Pr ess,s H19 99. , Four th Edit ion e rn et w or k ing Te chnologie a ndbook By Cisco Systems, Inc.

• Hein, Mat hias, and Dav id Gr iff it h s. Sw it ch ing Tech nology in t he Local Net w or k . New Yor k : I nt er Pub nat lishional er: Cisco Thom Pressson Pu blish in g, 1 997 . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

• Per lm an, Rad ia. I n t erconn ect ions, Second Edit ion : Br id ges, Rout ers, Sw it ches, and 28 I n t ernPages: et w or11 k in g Pr ot ocols. Bost on: Add ison Wesley , 19 99.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 31. Asynchronous Transfer Mode Switching • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Under st and t he ATM cell st r uct u re.

By Cisco Systems, Inc.

I dent if y t he ATM m odel lay er s. Pub lish er: Cisco Press

Know hetem ATM Pub Dat e: tSep ber 1connect 1, 2 003 ion

t yp es.

I SBN: 1- 58 705 -1 19 -2

Descr ibe t he call est ab lishm ent pr ocess. Pages: 11 28

Under st and t he p ur pose of each LANE com ponent . Descr ibe LANE op er at ion s. p ur pose of MPOA. The uKnow pdat edt he edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Asyn ch ron ous Tr ansf er Mode ( ATM) is an I nt er nat ion al Telecom mu nicat ion Union–Telecom m un icat ions St andar ds Sect ion ( I TU- T) st andar d for cell r elay wh er ein inf ormCon at ion iple sert vechn ice tolog yp es, ast ial v oice, v ideo, or dpr atofession a, is conv eyat edall in lev smels, all, ffix ed cisefor ovmu er vltiew s of iessuch essen t o n et wor k ing als rom size cells. ATM n etpert wor.k s ar e connect ion- or ien t ed. This ch apt er pr ov ides su m mar ies of ATM nov ice t o ex pr ot ocols, ser v ices, and oper at ion. Figur e 31 - 1 illust r at es a p riv at e ATM net w or k and a p ublic ATM net New w ork chapt carerr yin s include g v oice,cov video, erag ean ofd im dat por a t raf antfic. t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Autrheored Syiv stat ems, w or ldwNe idet w leader king or tATM he I n t er n et . or k Bot h Figu 3 1 by -1 Cisco . A Pr e ATM or k inannet d waorPu blf ic Ne tw Can Car r y Voi ce, Vide o, a nd Da t a Tr a ff ic I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing [ View full size im age] indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

•

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Standards ATM is based on t he ef for t s of t h e I TU- T Br oadband I nt egr at ed Ser v ices D ig it al Net w ork ( BI SDN) st an dar d. I t w as orig in ally con ceiv ed as a high - sp eed t r ansfer t echnology for v oice, video, and dat a ov er pub lic n et wor k s. The ATM Foru m ext en ded t h e I TU- T' s v ision of ATM for u se over •pu blic and prTable Content s Th e ATM For um h as r eleased w or k on t he f ollow in g specificat ions: iv at eofnet w or ks. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

User - t o- Net w ork I n t er f ace ( UNI ) 2 . 0

By Cisco Systems, Inc.

UNI 3. 0 Pub lish er: Cisco Press Pub UNI Dat e: 3.Sep 1 tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

UNI 4. 0 Pages: 11 28 Pub lic- Net w ork Node I nt er face ( P- NNI ) LAN Em ulat ion ( LANE) lt ip ocol ATM The uMu pdat edrotedit ionover of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ATM Devices and the Network Environment ATM is a cell- sw it ching and m ult iplexin g t echn olog y t hat comb ines t he b en ef it s of circuit sw it ch in g ( guar ant eed cap acit y and con st ant t ran sm ission delay ) w it h t hose of pack et sw it ch ing ( f lex ibilit y and efficiency for in t er m it t ent t r aff ic) . I t pr ov id es scalable b andw idt h f rom a f ew •m eg abit s p erTable of Content second ( Mbp ss) t o man y gigab it s per second ( Gbps) . Because of it s asyn ch r onous •nat u r e, ATM Iis ndex m or e eff icient t han sy nch ron ous t echnologies, such as t im e- d iv ision m ult iplex in g I( nt e rn et. w or k ing Te chnologie s H a ndbook , Four th Edit ion TDM) By Cisco Systems, Inc.

Wit h TDM, each user is assign ed t o a t im e slot , and n o ot h er st at ion can send in t hat t im e slot . I f a st at ion has mu ch d at a t o send , it can sen d only w hen it s t ime slot comes u p, even if all ot her Pub lish er: Cisco Press t im e slot s ar e em p t y. Howev er , if a st at ion h as not h in g t o t r ansm it w h en it s t im e slot com es up, Dat e: Sep tem ber 1 1, 2 003 t he Pub t ime slot is sent em pt y and is w ast ed. Because ATM is asy nchr onou s, t ime slot s ar e av ailable I 19 m -2 at ion ident if y in g t he sour ce of t he t ran sm ission cont ained in t he header of on demSBN: and 1-w58 it h705 in-1for Pages:cell. 11 28 each ATM

ATM Cell Basic Format The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of ATM t r ansfers infor m at ion in f ixed- size un it s called cells. Each cell con sist s of 5 3 oct et s, or b yt es. essent ial an d cu t t ing- edg e t ech nologies. The f ir st 5 by t es con t ain cell- header inf orm at ion, and t he r em ain ing 48 cont ain t he p ayload ( user inf orm at ion) . Sm all, fix ed - leng t h cells ar e w ell su it ed t o t r ansfer ring v oice and vid eo t r aff ic because t raf is sinof t oler ant olog of delays t hatt ial result fr wor om khav t o wait for at a pack Consuch cise ov erfic v iew t echn ies essen t o n et inging pr ofession als aatlar allge levd els, f rom et t o dow nload, amon g ot her t hing s. Figur e 31 2 illust r at es t he basic for m at of an ATM cell. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag Figu r ee 3of1 cut -2 t.ing Anedge ATM t echn Ceologies ll Conlik siestopt s ical of a n etHe worad k ing er and an d st or Pa age yl oad Da t a Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag ATM Devices e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr essionals at e. eTools gu idsw elines or dopt imendp izing oint systs.em for sw m ance w ill incr ease Anof ATM net w or koper is mad up ofand an ATM it ch fan ATM Anper ATM it ch is r espon sible pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost icients t he for cell t r ansit t hr ough an ATM net w ork . Th e job of an ATM sw it ch is w ell d ef ined: I t eff accept decisions for tfhrom eir net ork s. incom ing cell an wATM endp oint or anot h er ATM sw it ch . I t t h en r eads an d u pdat es t h e cell header inf or mat ion an d q uickly sw it ch es t he cell t o an ou t put int er face t ow ar d it s dest in at ion. An ATM en dpoint ( or end sy st em ) cont ain s an ATM n et wor k int er f ace ad apt er . Ex am ples of ATM endp oin t s ar e w or kst at ions, r ou t er s, dig it al ser v ice u nit s ( D SUs) , LAN sw it ch es, an d v ideo coder decoders ( COD ECs) . Figur e 31 - 3 illust r at es an ATM n et w or k m ade up of ATM sw it ches and ATM endp oin t s.

Figu r e 3 1 -3 . An ATM N et w or k Com pr i se s ATM Sw it ch es a nd Endp oint s

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Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

ATM Network Interfaces

Conncise ovkerconsist v iew s sofoft echn ies essen t ial etconn wor kect ingedprby ofession all lev els, rom An ATM et wor a setolog of ATM sw it ch est o in nt er poin t -als t o- at point ATM linfks or nov ice t o ex pert . int er faces. ATM sw it ches su ppor t t w o p rim ar y t y pes of int er faces: UNI an d NNI . Th e UNI connect s ATM en d sy st em s ( su ch as h ost s and r out ers) t o an ATM sw it ch. The NNI conn ect s t w o New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP ATM sw it ches. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Depend in g on w h et h er t he sw it ch is ow ned and locat ed at t he cust om er 's p rem ises or is pub licly ow ned and operby at ed by Sy t hesttems, elephon com p any , UNIin and can f bore tfu bdiv Aut h ored Cisco w oreldw ide leader net wNNI or king hert hI nert ersu n et . ided in t o pu blic and pr iv at e UNI s an d NNI s. A p r iv at e UNI connect s an ATM en dpoint and a pr ivat e ATM sw ch et . Iwt sorpu count er par t conn s an ATMt hendp iv at e it ch t o arefer pubence lic swt hat it ch. A I n t itern k inblic g Tech nologies Handect book , Four Ed itoin iont, or is aprcom prsw ehensive pr iv at e NNI connect s t w o ATM sw it ch es w it h in t he sam e pr ivat e org anizat ion. A pu blic one enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing connect s t w o ATM sw tithe ch es t he pubologies, lic org anizat t echnologies. Mast er t er w mits,hin con cepsam t s, teechn an d ion. devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . An ion t heedbrchapt oadb and in t er car rier erf ace opt ( B-ical I CI ) net , conn o pub lic y, Comaddit plet e wal it hspecif new icat an dion, u pdat er s on secur it y , in st tor age, w orect k insg,t wscalabilit sw it ch es f r om dif fer en t serv ice pr ovid er s. Figur e 31 4 illust r at es t he ATM int er face specificat and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial ions t o all for pror ivat lic net wr ork s.dless of ex pert ise. net w kineg and p rofpub essionals, egar Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on 3 1e -4 er fsace Speices, ci fi ca t ion Diailed ff e r descr f or Pr i vas,t erevaiew nd quest Publions ic a Figu b r oadr reang of .intATM egr al Isynt st em and serv in clud ings det ipt ion Ne t w and or kad s dit ional r esou r ces f or fu rt her st udy . t o en su re con cept comp r eh en sion and r et en t ion, Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich [ Viewf or fullopt sizeim imizing age] syst em per for m ance w ill incr ease pr of essionals oper at e. Tools and gu id elines pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ATM Cell Header Format An ATM cell header can be on e of t w o f orm at s: UNI or NNI . Th e UNI header is used f or com mu nicat ion b et w een ATM endp oint s an d ATM sw it ch es in pr iv at e ATM net w ork s. The NNI header is u sed for com m unicat ion bet w een ATM sw it ches. Figur e 31 - 5 d ep ict s t he b asic ATM cell •for m at , t he ATM TableUNI of Content s cell header f orm at , and t he ATM NNI cell header for m at . •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 3 1 -5 . An ATM Ce ll, ATM U NI Cel l, a nd ATM NN I Ce ll H ea der Each Con t a in 4 8 Byt es of Pa yl oad Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. t hehtead er mer s, does con cep t s,intclu echn an d devices used t oday ' s net w ork ing Unlike t he UNIMast , t heerNNI not deologies, t h e Generic Flow Cont r ol in ( GFC) field. induitstion ry .ally Lear n ehow incor por atae Vir int terual netPat w orh kin g ttechn in t ot hat a LAN/ WAN ent . Add , th NNI t oheader h as I d en ifier olog ( VPIies ) f ield occu pies env t heirf onm irst 12 Com ew it hfor new chapt s on y , itstches. or age, opt ical net w or k in g, scalabilit y, bit s, plet allow ing laran gerd tur pdat u nk sed bet w eenerpu blicsecur ATMitsw and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

ATM Fields ReaderCell s w ill Header obt ain a g reat er un der st an ding

of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Ianbaddit r oad ion r ang t oe GFC of intand egr al VPIsyhstead emer s and fieldserv s, sev ices, eralinot clud hering s are detused ailed indescr ATMipt cell ionheader s, rev iew f ields. quest Th ions e t o en su follow ing re descr con cept ipt ion comp s sum r ehmar en sion ize tand h e ATM r et encell t ion, header and ad f ields dit ional illu str esou r at edr ces in Figur f or fuert31 her - 5:st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Gene r ic oper Flowat e. Cont r ol and ( GFC) —elines Prov ides local nct ions, such ify ing ult iple pr of essionals Tools gu id f or opt imfu izing syst em peras forident m ance w illmincr ease t hdatimshar siniciency, gle ATMhelp in t erf field is t yp ically used, and set t o it s pr odust ctat ivions it y an pr ove ea eff ingace. t he This r eader m ake mor e innot t elligent cost is - eff icient defaufor lt vt halue of 0w ork ( bins.ary 0 000 ) . decisions eir net V ir t ua l Pa t h I de nt i fi er ( V P I ) — I n conj unct ion w it h t he VCI , ident if ies t he n ex t dest inat ion of a cell as it p asses t hr ou gh a series of ATM sw it ches on t he way t o it s dest inat ion. V ir t ua l Ch an nel I d en t if ie r ( V CI ) — I n conj unct ion w it h t he VPI , ident if ies t h e nex t

dest inat ion of a cell as it p asses t hr ou gh a series of ATM sw it ches on t he way t o it s dest inat ion.

• •

P ay loa d Typ e ( PT) — I n dicat es in t h e fir st b it w het her t h e cell cont ain s user dat a or cont r ol d at a. I f t he cell cont ains u ser d at a, t he bit is set t o 0. I f it cont ains cont r ol dat a, it is set t o 1. Th e second bit indicat es con gest ion ( 0 = n o cong est ion, 1 = con gest ion ) , and t h e t hir d bit in dicat es w het her t he cell is t h e last in a ser ies of cells t h at r epr esent a single AAL5 fr am e ( 1 = last cell f or t he f r am e) . Table of Content s

I ndex Cel l Loss Pr ior it y ( CLP ) — I n dicat es wh et her t he cell should be d iscar ded if it encount er s net w ork . I f t h e CLP bit eq uals 1, t he cell Cisco should Systems, be d Inc. iscar ded in p ref er ence t o cells w it h t h e CLP bit equal t o 0.

I nt e rn ext et w ror k ing Te chnologie H a ndbook Four Edit ion em e congest ions as it m ov,es t hrthough t he By

H e ade r Err or Cont r ol ( H EC) — Calcu lat es ch eck su m only on t h e fir st 4 by t es of t he header . HEC can cor r ect a single b it er ror in t h ese b yt es, t h er eby pr eser v ing t he cell r at her Pub Dat e: Sep tem ber 1 1, 2 003 t han d iscar ding it .

Pub lish er: Cisco Press

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ATM Services Thr ee t y pes of ATM ser vices ex ist : p er m anent v ir t u al cir cuit s ( PVC) , sw it ch ed v irt ual cir cu it s ( SVC) , and con nect ion less serv ice ( w hich is sim ilar t o SMDS) . •PVC allow s d Table Content irect of conn ect ivs it y bet w een sit es. I n t his w ay , a PVC is sim ilar t o a leased lin e. •Am ong it s adv I ndex ant ag es, PVC g uar ant ees availabilit y of a con nect ion and does n ot r equir e call Iset nt eup rn etpr w ocedu or k ing rTe s Hsw a ndbook , Four th Edit ionages of PVCs inclu de st at ic conn ect iv it y and eschnologie b et ween it ches. Disadv ant m anual set u p. Each piece of eq uipm ent bet w een t he sour ce and t h e dest in at ion mu st be By Cisco Systems, Inc. m anually p rov ision ed f or t he PVC. Fur t her m ore, n o net w or k r esilien cy is available w it h PVC. lish er: Cisco Press An Pub SVC is cr eat ed an d r eleased dy nam ically and r emain s in u se only as long as d at a is b eing Pub e: .Sep ber sen 1 1, se, 2 003it is sim ilar t o a t elep hone call. D yn amic call cont r ol r equ ir es a t r ansferDat r ed I ntem t his I SBN: 158 705 -1 19 -2 signaling pr ot ocol b et w een t he ATM en dpoint and t h e ATM sw it ch. Th e adv ant ag es of SVCs include Pages: con nect 11 28 ion f lex ibilit y and call set u p t h at can be h andled aut om at ically b y a n et w or k ing dev ice. Disadv ant ag es in clu de t h e ex t r a t im e an d over head r equ ir ed t o set u p t h e connect ion.

ATM Virtual Connections The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ialwan edg e t ech nologies. ATM net orkdscu art et ingf und ament ally conn ect ion- orient ed, wh ich m eans t h at a vir t ual ch annel ( VC) m ust b e set up acr oss t he ATM net w ork pr ior t o an y dat a t r ansfer . ( A v ir t ual chan nel is r oug hly equiv alen t t o a v ir t ual cir cu it . ) Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Tw o t y pes of ATM connect ions ex ist : v ir t ual p at hs, w h ich ar e ident ified by v irt ual p at h id en t ifiers, and v ir t ual chan nels, w hich ar e ident ified by t h e com b in at ion of a VPI and a v ir t ual chan nel New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP ident if ier ( VCI ) . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age A v ir t ual p at h is a b und le of v ir t ual ch annels, all of w hich ar e sw it ched t ran sp arent ly acr oss t he ATM net on tSy he st com m on All VPI s and s,orhow sign if ican ce Autwh ork oredbased by Cisco ems, w orVPI ldw. ide leader in VCI net w kingever f or, thav he Ien on t erly n etlocal . across a par t icular link an d ar e r emap ped, as appr opr iat e, at each swit ch. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat A t ran smnet ission patgh pisr ofessionals t h e ph ysicalt omun edderst ia t hat anspor t s v ir en t ual chan nels v ir er t u net al pat h s.ing enables w or kin andt r an d im plem t cont em porand ar y int w ork Figur e 31 6 illust r at es how VCs concat enat e t o creat e VPs, w hich, in t u rn , t r av er se t he m or t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w edia ork ing tindu r ansm ission pat h. st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

Figu r e 3 1 -6 . VCs Con ca t e na t e t o Cr e at e VPs

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ATM Switching Operations The b asic operat ion of an ATM sw it ch is st r aigh t for w ar d: The cell is receiv ed acr oss a link on a k now n VCI or VPI value. Th e swit ch looks up t he conn ect ion v alu e in a local t r anslat ion t able t o det er min e t he ou t going por t ( or por t s) of t he connect ion and t he n ew VPI / VCI v alu e of t he •connect ion on Table Content t h atoflink . Thse swit ch t hen r et r ansm it s t h e cell on t h at out going link w it h t he •app rop riat e con I ndex nect ion ident if ier s. Becau se all VCI s and VPI s hav e only local sign if ican ce acr oss Iantpear rn tet w or s H a ndbook Four thped, Edit ion icu lark ing lin Te k, chnologie t hese values ar e r,emap as necessar y , at each sw it ch . By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ATM Reference Model The ATM ar chit ect u re uses a logical m odel t o descr ibe t h e fu nct ionalit y t hat it su ppor t s. ATM fu nct ionalit y cor respond s t o t he ph ysical lay er an d par t of t h e dat a lin k layer of t h e OSI r ef erence m odel. •

Table of Content s

• I ndex m odel is com posed of t he f ollow ing plan es, w hich span all layer s: The ATM r eference I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Cont rol — This plane is responsible f or gener at ing and m anagin g sign alin g r equest s.

PubUlish Press seer: r—Cisco This plane

is responsible f or m anagin g t he t r ansfer of d at a.

Pub Dat e: Sep tem ber 1 1, 2 003

Ma na ge m705 en-1t 19 —-2This plane con t ains t w o com pon en t s: I SBN: 1- 58 Pages: 11 28

- Lay er man agement m anages lay er- specific f unct ions, such as t h e det ect ion of failur es and p rot ocol p r oblem s. - Plan e m anagem en t m an ages and coord in at es fu nct ions r elat ed t o t he com plet e em . of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of The u pdat edsyst edit ion essent ial an d cu t t ing- edg e t ech nologies. The ATM r eference m odel is com posed of t he f ollow ing ATM layer s: Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom P hyice si ca la ypert er — nov t ol ex . Analogous t o t h e phy sical layer of t h e OSI r eference m odel, t h e ATM ph ysical layer m anag es t he m edium - depend en t t r an sm ission . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP ATM l ay e r— Com bined w it h t h e ATM adapt at ion lay er , t h e ATM lay er is r ough ly analogou s tCov o t he d at of t he OSIologies ref er ence odel. ATM lay and er is st r esponsible f or t he erag e aoflink cut tlay ingeredge t echn lik e m opt ical The n et wor k ing or age simu lt aneous shar ing of v ir t u al cir cuit s ov er a phy sical link ( cell m ult iplex ing) and passin g Aut h ored cells t h rouby gh Cisco t he ATM Sy stnet ems, w orwkor( cell ldw ide relay leader ) . To in do net t h is, w orit king usesf or t het he VPII nand t er n VCI et . in for m at ion in t he h ead er of each ATM cell. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables ATM netawda orpt kina gt ion p r ofessionals la y er ( A AL) to — unCom derstbined and an w dit himt hplem e ATM en tlay cont er,em t he por AAL ar yisint r oug er net hly w ork ing t echnologies. analogouMast s t o er t het he d att a er link m s, lay conercep oft s, t het echn OSI ologies, m odel. The an d AAL devices is r espon used sib in tle oday for ' isolat s net wing ork ing indu sthigh ry . Lear er - lay n er how pr ot t oocols incor fr por omat teh int e det er net ailswof or kin t hegATM t echn prolog ocesses. ies in tThe o a adap LAN/ WAN t at ionenv layireronm pr epar ent . es Com plet user ew dat it ha new for con an d ver u pdat sion ed int ochapt cellserand s onsegm securenit tys, tst h or e dat age, a in opt t oical 4 8-net by twe or cell k inpay g, scalabilit loads. y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Finally, t he hig layer s r residing ab ove t he AAL net w or kin gp rofher essionals, egar dless of ex pert ise.accept user dat a, ar r ang e it int o pack et s, and han d it t o t he AAL. Figur e 31 - 7 illust r at es t he ATM r efer en ce m od el. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o enFigu su re rcon sion Ref and e r et en t ion, and adldit ional f or Low fu rt her e cept 3 1 -7comp . Thr eh e en ATM r en ce M ode Re la treesou s t or ces t he e stst udy Tw. o Cov erag e is also ext end edLa n ot only t o new n et wor k ing concep t s, but also t o old er , legacy ye r s of t h e O SI Ref e r en ce M ode l syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an dPhysical cu t t ing- edgLayer e t ech nologies. The ATM The ATM ph ysical ers hof ast echn fou r olog f uncties ions: Cells ertked a b it st rals eam t helev t ran smf rom ission Con cise ov er lay v iew essen t ialart oe nconv et wor ingint proofession at, all els, and r eceipt on .t he phy sical m edium are con t r olled, ATM cell boun dar ies ar e t rack ed , and nov ice of t o bit exspert cells ar e p ack aged int o t he app rop r iat e t yp es of fr am es for t h e ph ysical m ed iu m . For ex am ple, cells ar New e p ack chapt aged er s diff include erentcov ly f erag or SONET e of imt han por t fant or DSt opics 3 / E-like 3 mVoI ed ia P and t y pes. EAP The ATM Cov erag ph ysical e of lay cut er t ing is edge divid ed t echn int oologies t w o p art lik es: opt t heical p hy n sical et worm k ing edium and- depend st or ageen t ( PMD) sublay er and t he t ran sm ission conv erg en ce ( TC) sub layer . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The PMD sub layer p rov ides t w o k ey fu nct ions. First , it syn ch ron izes t ran sm ission an d r ecept ion I n t ern et in w or k indg receiv Tech nologies Hand bookflow , Four , is a com ehensive refer t hat by send g an ing a cont in uous of tbhit Ed s witition h associat edprt im ing in for m atence ion. Second, it enables or kin g p rm ofessionals t o pun an d im plem en t cont em porect ar or y int netan w dork ingle. specif iesnet t hew ph ysical ed ia f or t he hyderst sical and m edium used , including conn t y er pes cab t echnologies. Mast er tm heedt iu er m s, con cep d devices used inalt oday ' s net w ork ing Ex am ples of phy sical st andar d st s,fort echn ATMologies, includean Syn ch ron ous Dig it induar st ry . Lear t o incor por at ew intork er net wH/ or SONET) kin g t echn olog t o5aMbps LAN/ WAN env onm . Hier chy / Synnchhow r onous Opt ical Net ( SD , DS3/ies E3,in15 over m ultirim odeent f iber plet e w it thhe new d uen pdat er se,onand secur , st or 8B/ age,10opt ical w or k intg, scalabilit (Com MMF) using 8 B/an 10B coded ingchapt sch em 15 5it yMbps B ov er net sh ielded w ist ed- pairy, h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all (and STP)speed, cab lintg. net w or kin g p rof essionals, r egar dless of ex pert ise. The TC sub lay er has four fun ct ion s: cell delin eat ion , header err or con t rol ( HEC) seq uence Reader w illand obt ver ain ificat a g reat un der ding lin of g, LAN and WAN n et w or k ing, p ar t icu ly The t h e cell gener atsion ion,ercellr at est an d ecoup an d t ran sm ission f ram e ad apt at lar ion. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided delineat ion f un ct ion m aint ains ATM cell boun dar ies, allow ing devices t o locat e cells wit h in a on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest st r eam of bit s. HEC seq uence generat ion an d v erif icat ion gener at es and check s t h e header erions ror tcont o enr su cont cept comp eh endat sion and rrat et en t ion, and ional r ces f or fu rt her udy .t s or ol re code o ensur e vralid a. Celle decou plingadmdit ain t ainsr esou sy nchr onizat ion andstinser Cov e isidalso ext end ed n otATM onlycells t o new n et wort he k ing t s, but er ,plegacy supperag resses le ( unassigned) t o ad apt r atconcep e of v alid ATMalso cellst ot oold t he ayload syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in int w hich capacit y of t he t ran sm ission syst em . Tr ansm ission fr am e adapt at ion p ack ages ATM cells o pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease fr am es accept ab le t o t he par t icular ph ysical lay er im plem en t at ion. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ATM Adaptation Layers: AAL1 AAL1 , a conn ect ion- or ient ed ser v ice, is suit able f or han dling const ant bit r at e sou rces ( CBR) , such as voice and v ideoconfer en cin g. ATM t r anspor t s CBR t r af fic using circuit - em ulat ion ser v ices.

Cir cuit - emu lat ion ser vice also accom m odat es t h e at t achm ent of eq uipm ent cur r ent ly using leased lin es t o an ATM backb one net w or k . AAL1 r eq uir es t im ing sy nchr onizat ion bet w een t he sour ce and t he d est inat ion . For t his r eason, AAL1 d ep en ds on a m edium , such as SONET, t hat supp ort s clock ing. The AAL1 pr ocess pr epar es a cell for t ran sm ission in t hr ee st ep s. Fir st , syn ch r onous sam ples ( for exam ple, 1 by t e of d at a at a sam pling r at e of 12 5 m icr oseconds) are in ser t ed in t o t h e Payload field. Second, Seq uence Num ber ( SN) and Seq uence Num ber Pr ot ect ion ( SNP) fields ar e add ed • Table of Content s t o pr ovid e infor m at ion t hat t he r eceiv in g AAL1 uses t o v erif y t hat it h as r eceiv ed cells in t he • I ndex corr ect or der . Thir d, t he r emain der of t he Pay load field is f illed w it h enou gh sin gle by t es t o eq ual I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion 48 by t es. Figur e 31 - 8 illust r at es how AAL1 pr ep ar es a cell f or t r ansm ission. By Cisco Systems, Inc.

Pub lish er: Cisco Press

Figu r ee: Sep 3 1tem -8ber . AAL1 Pub Dat 1 1, 2 003 Pr e par e s a Cel l f or Tr a nsm ission So Tha t t he Ce lls Re t a in Th ei r O r de r I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy ATM Adaptation Layers: AAL2 syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Anot h ct er ivt it r affic t yp has r eq uirhelp em ent lik er eader CBR bumt ake t endmor s t oe be rst y in nat u- eff r e.icient This is pr odu y an d ime pr ov et im effing iciency, ings t he in t bu elligent , cost called v ariable b it r at e ( VBR) t r aff ic. This t y pically inclu des ser v ices char act erized as pack et ized decisions for t h eir net w ork s. v oice or video t hat do n ot h ave a const ant dat a t r ansmission speed but t hat do hav e r eq uir em ent s sim ilar t o const an t bit r at e ser v ices. AAL2 is suit able f or VBR t r aff ic. The AAL2 pr ocess u ses 4 4 b yt es of t he cell pay load f or user dat a and r eser ves 4 by t es of t he p ayload t o supp ort t he AAL2 pr ocesses. VBR t r aff ic is ch aract er ized as eit her r eal- t im e ( VBR- RT) or as non - r eal- t im e ( VBR- NRT) . AAL2

supp ort s bot h t y pes of VBR t r affic.

ATM Adaptation Layers: AAL3/4 AAL3 / 4 su ppor t s b ot h con nect ion - orient ed and connect ionless d at a. I t w as design ed f or net w or k ser v ice pr ovider s and is closely align ed w it h Sw it ch ed Mu lt im egabit Dat a Ser v ice ( SMDS) . •AAL3 / 4 is used Table t o oft r Content ansmits SMDS packet s ov er an ATM n et wor k . •

I ndex

IAAL3 nt e rn/et k ing Te chnologie s Ht ar ndbook , Four th ionst eps. First , t he conv erg en ce su blayer ( CS) 4wporr ep ares a cell f or ansm ission inEdit f our creat es a pr ot ocol dat a unit ( PDU) b y pr epending a beginnin g/ end t ag header t o t he f ram e an d By Cisco Systems, Inc. app en ding a leng t h f ield as a t r ailer . Secon d, t h e seg ment at ion an d r eassem bly ( SAR) sublay er fr ag ment s t he PD U and pr ep en ds a header t o it . Then t he SAR sublay er append s a CRC- 1 0 t railer Pub lish er: Cisco Press t o each PDU f rag ment f or er r or cont r ol. Finally, t he com plet ed SAR PDU b ecom es t he Pay load Pub Dat e: Sep tem ber 1 1, 2 003 field of an ATM cell t o w hich t he ATM lay er p r ep en ds t he st an dar d ATM h ead er . I SBN: 1- 58 705 -1 19 -2 Pages: 28 PD U header consist s of Typ e, Sequ en ce Num ber, and Mult ip lex ing I d en t ifier An AAL 3/ 4 11 SAR fields. Ty pe f ields ident ify w h et h er a cell is t he b eg inning , cont inu at ion, or end of a message. Sequence nu m ber fields ident if y t he ord er in w hich cells should be reassem bled. Th e Mult iplex in g I dent if ier f ield det erm ines w h ich cells f rom diff er ent t r aff ic sou r ces ar e int er leav ed on t h e same v irt u al circuit connect ion ( VCC) so t hat t he cor r ect cells ar e r eassem bled at t he dest inat ion.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

ATM Adaptation Layers: AAL5 Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom AAL5 nov is t hice e pr y AAL t oimar ex pert . f or dat a and supp ort s bot h connect ion- or ien t ed an d conn ect ionless dat a. I t is used t o t r ansf er most non- SMDS d at a, such as classical I P ov er ATM and LAN Em ulat ion chapt ( LANE) also k now n as h e tsim an dlike ef ficien t at ion lay er ( SEAL) New er .s AAL5 include coviserag e of im tpor ant ple t opics VoI Pt adap and EAP because t he SAR sub lay er simp ly accept s t he CS- PD U and seg ment s it int o 48- oct et SAR- PDUs w it hout an yt ing by t edge es in each Covr eser eragvin e ofg cut t echn cell. ologies lik e opt ical n et wor k ing and st or age AAL5 Aut pr epar es by a cell for Sy t ran sm ission in tide hr eeleader st ep s.inFir st w , tor h eking CS fsub h ored Cisco st ems, w or ldw net or tlayer he I nap t erpends n et . a v ariablelengt h pad an d an 8- by t e t r ailer t o a f r ame. Th e pad ensur es t hat t he r esu lt ing PDU falls on t h e I n t-ern 48 by tet e wbou or kndar in g Tech y of an nologies ATM cell. HandThe book t railer , Fourincludes t h Ed it ion t h ,e islen a gt com h of prtehensive he f r ame refer and ence a 3 2-tbit hatcy clic renables ed und ancy net wcheck or kin g( CRC) p r ofessionals com put ed t o acr un oss derst t hand e enan t ire d im PDU. plem This en t allow cont em s t he porAAL5 ar y int receiv er neting w ork pring ocess to echnologies. det ect bit erMast r ors,erlost t he cells, t er m s, or con cells cep t ht at s, tar echn e out ologies, of seqan uence. d devices Second used , t he in SAR t odaysub ' s net layer w ork ing indumsten seg ryt.sLear t he nCShow PDU t o int incor o 48porby attee int blocks. er net w A or header kin g t echn and tolog r ailer iesare in t onot a LAN/ added WAN ( asenv is in ir onm AAL3/ ent 4 .) , Com so mplet essages e w it hcann newotan b ed int u pdat erleav ed ed chapt . Finerally s on , t he secur ATM it y layer , st or age, places opteach ical net block w orint k in o g, t he scalabilit Pay loady, and speed, field of an ATM t h is cell. bookFor is aallcom cells plet execept an d tuhe p- tlast o- d,ataebritefin er ence t he Pay t o load t he t Typ op ics e (tPT) hat field are essen is sett ial to 0 t o t all o net indicat w orekin t hgatp rof t h eessionals, cell is notr egar t he last dless cell of in exapert serise. ies t hat r ep resen t s a sing le fr am e. For t he last cell, t h e bit in t h e PT f ield is set t o 1. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ATM Addressing The I TU- T st an dar d is b ased on t he u se of E. 164 add r esses ( sim ilar t o t elephon e nu mb er s) f or pu blic ATM ( B- I SD N) net w or ks. Th e ATM For um ex t ended ATM addr essing t o in clu de pr iv at e net w or ks. I t decid ed on t he su bnet w or k or ov er lay m odel of ad dr essing, in w hich t he ATM lay er •is r esp onsib le Table of ap Content for m ping snet w or k layer ad dr esses t o ATM addr esses. This sub net w or k mod el is •an alt er n at iv e I ndex t o using net w or k layer p rot ocol addr esses ( such as I P and I PX) an d ex ist in g Ir nt e rn et wpr orot k ing Te chnologie s HI aGRP ndbook , Four th .Edit out ing ocols ( such as and RI P) Th ion e ATM For um d ef ined an ad dr ess f or mat based on t heCisco st r uSystems, ct u re of Inc. t he OSI net w ork ser vice access poin t ( NSAP) addr esses. By Pub lish er: Cisco Press

Subnetwork of Addressing Pub Dat e: Sep tem Model ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

The suPages: bnet w11or 28k m odel of addr essin g d ecoup les t he ATM lay er f rom any exist ing hig her- lay er pr ot ocols, su ch as I P or I PX. Ther ef or e, it r equir es an ent ir ely new ad dr essing schem e and r out ing pr ot ocol. Each ATM sy st em m ust b e assign ed an ATM addr ess, in add it ion t o any h igher lay er p r ot ocol addr esses. This r equir es an ATM ad dr ess r esolu t ion p rot ocol ( ATM ARP) t o map high er - lay er addr esses t o t heir corr espond in g ATM add r esses. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

NSAP Format ATM Addresses

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The 2 0- b yt e NSAP- f or mat ATM addr esses ar e designed for u se wit h in p riv at e ATM net w or ks, nov ice t o ex pert . w her eas public n et w or k s t y pically use E. 164 ad dr esses, w h ich ar e for m at t ed as defin ed by I TUT. Th eNew ATMchapt For um as specif iederag an eNSAP f or E.like 16 4 VoI ad dr w hich is u sed for er s hinclude cov of imencoding por t ant t opics P esses, and EAP encoding E. 16 4 addr esses w it hin pr ivat e net w ork s, bu t t h is addr ess can also b e used b y some pr iv atCov e net w oreks. erag of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Such Aut pr ivat e net s can base ow nide ( NSAP f orinmat ) wadd ressin g ton E.n16 h ored byw ork Cisco Sy st ems,t heir w or ldw leader net or king f or het hI net er et4. ad dr ess of t he pu blic UNI t o w hich t hey ar e connect ed an d can t ak e t he addr ess pr ef ix fr om t h e E. 16 4 n um ber , ident ying by t h e Hand lowerbook - or der bit s.t h Ed it ion , is a com pr ehensive refer ence t hat I n t ernifet w orlocal k in g nod Teches nologies , Four enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing All NSAP- f ormMast at ATM esses con cep sist t of hr ee ologies, com pon an en tds:devices t h e autused h orit yinan d for' smnet at ident if ier t echnologies. er tad hedr t er m s, con s, tt echn t oday w ork ing (indu AFI )st, ry t he in it ial dom ain id en t ifier ( I DI ) , and t h e dom ainspecif ic par t ( DSP) . Th e AFI id en t ifies . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . tCom he tplet yp e eand m atan ofdt he I DIed , wchapt hich, er in st uon rn secur , ident t h age, e addopt ress allocat and w it hfornew u pdat it if y ,ies st or ical net w ion or k in g, scalabilit y, adm inist r at ive aut hor it y . The D SP cont ains act u al r out ing inf or mat ion . and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on NOrTE a b r oad ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Sumemisaralso iz edext anot h er t he tf o ir st 13 nby es for m concep t h e NSAP efix t hat s the Cov erag end ed w n ay, ot only new ettwor k ing t s, pr but also t o answer old er , legacy qu est ion, " Which sw it ch?" Each sw it ch mu st hav e a pr ef ix v alu e t o uniqu ely ident y itw.hich syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent sifin Dev ices at t ached t o t he sw it ch inh er it t he pr efix v alue f r om t he sw it ch as par t of t h eir pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease NSAP ad dr ess. The pr ef ix is used b y swit ches t o supp ort ATM rou t ing. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The n ex t 6 by t es, called t h e end st at ion ident ifier ( ESI ) , ident if y t he ATM elem ent at t ached t o t h e sw it ch . Each device at t ached t o t he sw it ch m ust hav e a u nique ESI v alue. The last by t e, called t he select or ( SEL) by t e, ident ifies t h e int ended pr ocess w it hin t he dev ice t hat t he connect ion t arg et s.

Thr ee for m at s of p riv at e ATM addr essing d if fer b y t he n at ur e of t he AFI an d I D I . I n t h e NSAPencoded E. 164 f orm at , t he I DI is an E.1 64 num b er . I n t he D CC for m at , t h e I D I is a d at a coun t r y code ( D CC) , w h ich ident if ies p art icular cou nt r ies, as specified in I SO 316 6. Such add resses ar e adm inist ered by t h e I SO Nat ion al Mem ber Body in each count ry . I n t he I CD f orm at , t he I DI is an int er nat ional cod e desig nat or ( I CD) , w hich is allocat ed by t h e I SO 6 523 r eg ist r at ion aut h orit y •( t h e Brit ish St Table of d Content andar s I n stsit ut e) . I CD codes ident ify par t icu lar int ern at ional or gan izat ions. •

I ndex

IThe nt e rn ATM et w or For k ing umTerchnologie ecom m ends s H a ndbook t hat or , Four g anizat th Edit ions ion or p r iv at e n et w or k serv ice pr ov id er s u se eit h er tBy heCisco DCCSystems, or t h e IInc. CD f or m at s t o f or m t heir ow n num b er ing plan.

Figur e 31 - 9 illust r at es t he t hr ee for m at s of ATM addr esses used f or pr iv at e net w or ks. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Figu Pages: r e113281 -9 . Th r ee For m at s of ATM Addr e sse s Ar e Used f or Pr iv at e Ne t w or k s

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich ATM Address Fields pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient The f ollowfor in gt d ipt w ions decisions h escr eir net ork sum s. m ar ize t he f ield s illu st r at ed in Figur e 31 - 9: AFI — I d en t ifies t he t yp e and for m at of t he add ress ( E. 1 64, I CD, or D CC) . D CC— I d en t ifies par t icular count r ies.

H ig h- O rde r D om a in - Sp ecif ic Pa rt ( H O- D SP ) — Com bines t he rou t ing dom ain ( RD) and t he area id en t ifier ( AREA) of t he NSAP add resses. The ATM For um com bined t hese fields t o supp ort a flexible, m ult ilevel ad dr essing hierar chy f or pr efix - based r out in g pr ot ocols. End Sy st em I de nt if ie r ( ESI ) — Specif ies t h e 48 - bit MAC ad dr ess, as ad min ist er ed b y t he I nst it ut e of Elect r ical and Elect ron ic Eng in eer s ( I EEE) . • •

Se le ct or ( SEL) — I s used f or local mu lt iplex ing w it hin end st at ion s and has no n et wor k Table of Content s signif icance. I ndex

I nt e rn IetCD w or— k ing Te chnologie a ndbook Four Edit ion I d en t ifies pars tHicular int,er natthional org anizat ions. By Cisco Systems, Inc.

E. 1 6 4 — I n dicat es t he BI SDN E. 164 add ress. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ATM Connections ATM su ppor t s t wo t y pes of connect ions: poin t - t o- poin t and p oin t - t o- m ult ipoin t . Point - t o- point con nect s t w o ATM end sy st ems and can b e unidir ect ion al ( one- w ay •com mu nicat ion Table Content ) orof bidir ectsional ( t w o- w ay comm u nicat ion ) . Point - t o- mu lt ipoint con nect s a •single- sour ceI ndex end sy st em ( kn own as t he r oot n ode) t o m ult iple dest inat ion end sy st ems ( kn ow n Ias nt eleaves) rn et w or.k ing Te chnologie H a ndbook , Four th Edit ion only. Root nodes can t ran sm it t o leav es, b ut Such connect sions ar e un idir ect ional leaves cannot t r ansm it t o t he r oot or t o each ot her on t he sam e conn ect ion. Cell replicat ion is By Cisco Systems, Inc. don e w it hin t he ATM net w or k by t h e ATM sw it ches w her e t he conn ect ion split s int o t w o or m or e br anches. Pub lish er: Cisco Press

Datbe:e Sep temable ber 1 1, I t wPub ou ld desir in2 003 ATM net w ork s t o hav e bidir ect ion al m ult ipoint - t o- m ult ipoint connect ions. I SBN: 158 705 -1 19 -2 Such connect ions ar e analogou s t o t he br oad cast ing or m ult icast ing cap abilit ies of shar ed- m edia LANs, Pages: such 11 as28Et h er n et and Tok en Rin g. A br oadcast in g cap abilit y is easy t o imp lem ent in shar ed - m ed ia LANs, w her e all n odes on a single LAN seg ment m ust p r ocess all pack et s sent on t hat seg m en t .

Unfor t u nat ely, a m ult ipoint - t o- m ult ipoint capabilit y cannot be im plem en t ed b y using AAL5, w hich is t he m ost com m on AAL t o t r ansm it dat a across an ATM net w ork . Unlik e AAL3/ 4, w it h it s The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Messag e I dent ifier ( MI D) field, AAL5 d oes not pr ovide a w ay w it hin it s cell for m at t o int er leav e essent ial an d cu t t ing- edg e t ech nologies. cells f r om diff erent AAL5 pack et s on a single conn ect ion. This m ean s t hat all AAL5 p ack et s sen t t o a par t icular d est inat ion across a par t icular connect ion mu st be r eceiv ed in seq uence; ot her w ise, t h eovdest inatsion bly rocesst ial w illt obe le pr ofofession reconst rals uctat ingallt he ack fet s. Con cise er v iew of reassem t echn olog iesp essen n etincapab wor k ing levpels, rom nov ice t o ex pert . This is w h y AAL5 point - t o- m ult ipoint con nect ion s can b e only u nidir ect ional. I f a leaf nod e w ere t o t ran smitchapt an AAL5 packet cov onterag o t hee conn ex amp it P w ould be r eceiv ed by bot h t he New er s include of imect porion, t antf or t opics likele,VoI and EAP r oot n ode and all ot her leaf n odes. At t h ese nod es, t he pack et sen t b y t he leaf could be int er leav w it s sent t he ologies r oot andlikpossib ly ot leaf n odes, pror eclud Coved erag e hofpack cut tet ing edgebyt echn e opt ical n her et wor k ing and st age ing t he r eassemb ly of any of t h e int erleav ed pack et s. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ATM and Multicasting ATM requ ires som e for m of m ult icast capab ilit y . AAL5 ( w h ich is t he most com m on AAL for d at a) cur r en t ly does not suppor t int er leav ing packet s, so it does not supp ort m ult icast in g. •I f a leaf nodeTable t ranof smContent it t ed as p ack et on t o an AAL5 connect ion, t h e pack et could be int er m ix ed w it h •ot her p ack et s I ndex and b e imp rop er ly r eassem bled . Thr ee m et h ods h ave b een pr oposed for solv in g It his nt e rn w or k ing Te chnologie s Hing, a ndbook Edit ion, and ov er laid point - t o- mu lt ip oint con nect ion . p et r oblem : VP m ult icast m u lt, Four icastthser ver By Cisco Systems, Inc.

Under t h e fir st solut ion, a m ult ipoint - t o- m ult ipoint VP link s all n odes in t he m ult icast gr oup , and each n ode is giv en a uniq ue VCI value wit h in t he VP. I nt er leav ed packet s h en ce can be id en t ified Cisco Press by tPub helish uner: ique VCI v alu e of t he sour ce. Un for t un at ely , t his m echan ism wou ld r equir e a pr ot ocol Pub Dat e: Sep tem ber 1, 2 003 t o uniqu ely allocat e 1VCI values t o nod es, an d such a p rot ocol mechanism cur r ent ly does not I SBN: 158 705 -1 19 exist . I t is also unclear-2 w het her cur r en t SAR dev ices could easily supp ort such a m ode of oper atPages: ion. 11 28 A m u lt icast ser ver is an ot her pot ent ial solut ion t o t he p r oblem of mu lt icast ing ov er an ATM net w or k. I n t h is scenar io, all n odes w ant ing t o t r ansmit ont o a m ult icast gr ou p set u p a point - t opoint connect ion wit h an ext er nal device k now n as a m ult icast serv er ( per hap s bet t er descr ibed as a resequencer or ser ializer ) . The m ult icast ser v er, in t u rn , is connect ed t o all nod es w ant ing The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t o receiv e t h e m ult icast packet s t hr ough a point - t o- m u lt ip oin t conn ect ion. The m ult icast serv er essent ial an d cu t t ing- edg e t ech nologies. r eceives p ack et s across t h e point - t o- point connect ions and t h en r et r ansmit s t hem across t h e point - t o- m ult ipoint connect ion—bu t on ly aft er ensur ing t hat t he packet s ar e serialized ( t hat is, one pCon acket is ov fully r ansm ed b ef or eies t he n ex tt ial is sent ) . wor I n tkhis ayofession , cell in als t er leaving isels, f rom cise er vtiew s ofitttechn olog essen t o n et ingwpr at all lev pr eclunov ded. ice t o ex pert . An over laidchapt p oint m ult ipoin conn is tt he p ot en tVoI ial solut t o t h e pr oblem of New er- st oinclude covterag e ect of ion im por antt hird t opics like P andion EAP m ult icast in g ov er an ATM n et wor k . I n t his scen ario, all nodes in t he m u lt icast g r oup est ablish a point -Cov t o- m ult ipoint connect ion w it h each ot hlik er enode in tnhe gr oup urage n, b ecom e leav es in erag e of cut t ing edge t echn ologies opt ical et wor k ingand, andinsttor t he eq uivalent connect ions of all ot h er nodes. Hence, all nodes can bot h t r ansm it t o and r eceive fr om Aut all ot h ored her nod by es. Cisco Th Sy is solu st ems, t ionwror equir ldw es ideeach leader nodine net to w maint or king ain f or a con t henect I n t er ionn et f or . each t r ansm it t ing m em ber of t h e gr oup , w hereas t h e m ult icast - ser ver m ech anism r eq uir es only t w o I n t ern etions. w or k in g Tech nologies Hand t hesEdaitrion , israt a ion comppr ehensive refer hatnod es connect This t yp e of con nect ionbook also, rFour equir egist rocess for inf or mence in g t the w oup or kinof gp r ofessionals t o in un tderst t cont y int netpoin w ork tenables hat j oin net a gr t he ot her nodes he grand oupan sod tim hatplem t he en new nodem es por canarfor m er t he t - ing t ot echnologies. Mast ion. er t he mher s, con s, tst echn ologies, d devices used t oday ' s net ork ing m ult ipoint connect Thteerot nodcep es tmu k now ab outant he n ew node soint hat t hey canwadd t he indu st ry . Lear n how incor -por e ltint netcon w ornect kin gion t echn olog in t o -aser LAN/ env ir onm new n ode t o t heir owtno point t o-at mu iper oint s. The mies ult icast verWAN m echanism is ent m or. e Com plet d nect u pdat chapt er s bu ont secur or age, of opt icaliring net waorcent k in g, scalabilit y, scalab le einwt it erhmnew s of an con ionedr esou r ces h as t it hey ,pst r oblem requ ralized speed, t,h w is hich bookisisbot a hcom e tan u p-t leneck t o- d at eand r ef er t he t of op failur ics t hat rand esequencer a pplet ot en ialdbot a ence sing let opoint e. are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ATM Quality of Service ATM su ppor t s QoS gu aran t ees com pr isin g t raf fic con t ract , t raf fic shap ing, and t r affic policing . At r aff ic con t ract sp ecifies an en velope t hat d escr ibes t he int en ded d at a f low . This env elop e •specif ies v alues Table of peak Content s dw idt h , aver age sust ained ban dw idt h, and bur st size, am ong f or ban •ot her s. WhenI ndex an ATM end syst em conn ect s t o an ATM n et w or k , it en t er s a con t r act w it h t he Inet nt ew rnor et k, w orbased k ing Teon chnologie s Ha ndbook , Four th Edit ion QoS par am et er s. By Cisco Systems, Inc.

Tr aff ic shap in g is t he use of q ueues t o const r ain dat a bur st s, limit peak dat a r at e, and smoot h jit t er s so t hat t raf fic w ill f it w it hin t he pr omised env elope. ATM devices are responsible f or lish er: Cisco Press adhPub er ing t o t he cont r act b y m ean s of t r aff ic shaping . ATM sw it ches can use t r aff ic policing t o Pub ber .1 1, 2 003 enfor ceDat t he:e Sep contem t r act The sw it ch can m easur e t h e act ual t r af fic f low and com par e it ag ain st t he I SBN: 158 705 -1 19 -2 agr eed - upon t r af fic env elop e. I f t h e sw it ch f in ds t h at t r af fic is out side of t he ag reed- up on par amPages: et er s,11it28can set t h e cell- loss pr iorit y ( CLP) bit of t he off ending cells. Set t ing t h e CLP bit m akes t h e cell discar d eligible, w hich m ean s t hat any sw it ch h andling t h e cell is allow ed t o dr op t he cell du r in g periods of con gest ion .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ATM Signaling and Connection Establishment When an ATM d ev ice w ant s t o est ab lish a conn ect ion w it h anot her ATM dev ice, it send s a signaling - requ est packet t o it s d irect ly connect ed ATM swit ch. This r equest cont ain s t he ATM add ress of t he desir ed ATM endp oin t , as w ell as an y QoS p ar amet er s r eq uired for t he conn ect ion. •

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•ATM sig naling I ndex pr ot ocols var y b y t he t y pe of ATM link , w hich can b e eit h er UNI sign als or NNI Isignals. nt e rn et wUNI or k ing chnologie H a ndbook , Four th Edit is Te used b et wseen an ATM end sy stion em and ATM sw it ch across ATM UNI , an d NNI is used acr oss NNI link s. By Cisco Systems, Inc.

The ATM For um UNI 3. 1 specif icat ion is t he cu rr ent st andar d for ATM UNI sig naling. The UNI 3. 1 Pub lish er: Cisco Press specif icat ion is based on t he Q. 29 31 pub lic net w ork sign alin g pr ot ocol dev eloped by t h e I TU- T. e: Seprtem 1 1, 003 car r ied in a w ell- k now n def ault conn ect ion: VPI = 0, VPI = 5. UNIPub sigDat naling eqber uest s 2are I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The ATM Connection-Establishment Process ATM sig naling uses t he one- p ass m et hod of conn ect ion set u p t h at is u sed in all m odern t elecom m unicat ion net w ork s, such as t he t elephon e net w or k. An ATM connect ion set up pr oceed s The u pdat eding editmion selling all-end in- one ork ds ingar ef erenceionp rov cover in t he f ollow annofert.he Firbstest , t-he sour ce systnet emwsen connect sigides naling r eqage uestof. The essent ial an d cu t t ingedg e t ech nologies. connect ion requ est is pr opagat ed t hr oug h t he n et w or k . As a result , conn ect ions are set u p t hr ou gh t he n et w or k . The conn ect ion r eq uest r each es t he fin al dest inat ion, wh ich eit her accept s or r eject s t he con nect ion r eq uest . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and Connection-Request Routing and Negotiation

EAP

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Rou t ing of t he conn ect ion r eq uest is gov ern ed by an ATM r out ing p rot ocol ( Priv at e Net w ork Net w ork t er f ace [ PNNISy ] , st wh ich rwout ect ionsinb ased onking destf or in att he ionI nand Aut hI nored by Cisco ems, or es ldwconn ide leader net w or t er nsou et . rce ad dr esses) , t r aff ic, and t he QoS par am et er s r equest ed b y t he sou rce end syst em . Negot iat ing a con nect ion rI neqt ern uest t hor atk is by t heHand dest inat ion is limit editbecause t ing is based on p aram et w in gr eject Teched nologies book , Four t h Ed ion , is a call com rou pr ehensive refer ence t hat et ers of init ial conn ect ion; chang in g p ar amet er s m ig ht aff ect t he conn ect ion r out ing. Figur e 31 - 10ing enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork high lig ht s t he onepass m et hod of ATM con nect ion est ablish m en t . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all re 1 -1 0 . ATM Dedless vi ces Est a bli netFigu w or kin g p3rof essionals, r egar of ex pert ise.sh Conn ect i on s Thr ou gh t h e O ne -

Pass M e t h od Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ATM Connection-Management Messages A n um ber of connect ion- m anag em ent m essage t y pes, including set up, call pr oceeding , connect , and r elease, ar e used t o est ab lish and t ear dow n an ATM conn ect ion. The sour ce end sy st em sen ds a set u p m essag e ( including t h e addr ess of t he d est inat ion end syst em and an y t r aff ic QoS •par am et er s) Table w h enofitContent wan t ss t o set up a conn ect ion. The ing ress swit ch sen ds a call pr oceeding •m essage b ack I ndex t o t h e sour ce in r esp onse t o t he set up message. The d est inat ion end syst em nex t Isen nt e ds rn etaw con or k ing Te chnologie H atndbook , Four th nect m essages if h e connect ionEdit is ion accept ed. Th e dest in at ion en d sy st em send s a r elease m essageInc. b ack t o t he sou rce end sy st em if t h e con nect ion is r eject ed , t her eby clear ing t he By Cisco Systems, connect ion. Pub lish er: Cisco Press

Con nect ion - man agem en t m essages ar e u sed t o est ablish an ATM connect ion in t he follow in g Pub Dat e: Sep tem ber 1 1, 2 003 m anner . First , a sour ce en d sy st em send s a set up m essage, w hich is for w ar ded t o t h e fir st ATM 1- 58 705 sw it ch I(SBN: ing ress sw-1 it 19 ch-2 ) in t he n et wor k . This sw it ch send s a call pr oceed in g message and inv ok es Pages: an ATM r ou t11 in28 g pr ot ocol. The signaling r equest is p rop agat ed acr oss t he net w ork . Th e ex it sw it ch ( called t he eg ress sw it ch ) t h at is at t ached t o t he dest inat ion end sy st em r eceives t h e set u p m essage. Th e eg ress sw it ch f orw ar ds t he set up m essage t o t he end sy st em acr oss it s UNI , an d t he ATM end syst em sends a connect m essag e if t he connect ion is accept ed. The connect m essage t rav erses back t h rou gh t he n et wor k alon g t h e same pat h t o t he sour ce en d sy st em , w hich sended s aedit conn messag backnet t owtork he ing d estrinat ion t opack he of The u pdat ionect of ack t he now b estledge - selling all- in-eone ef erence rovnow idesledge cover tage connect ion. D at a t r ansf er can t hen begin. essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

PNNI PNNI pr ov ides t w o sign if ican t ser vices: ATM t op ology discover y and call est ablish ment . For sw it ch es t o bu ild conn ect ions b et ween en d p oint s, t he sw it ch mu st k now t he ATM net w ork t opolog y. PNNI is t he ATM r out ing pr ot ocol t h at enab les sw it ches t o au t om at ically d iscov er t he •t opolog y andTable of Content t he ch aract ersist ics of t he lin ks in t er conn ect ing t he sw it ches. A link - st at e p rot ocol •m uch lik e OSPF, I ndexPNNI t rack s t hing s such as band w id t h on link s. Wh en a sign ificant ev ent occur s It hat nt e rnchang et w or kes ingt he Te chnologie H a ndbook ion an nounces t h e ch ange t o t h e ot her sw it ch es. char act serist ics of ,aFour linkth, Edit PNNI By Cisco Systems, Inc.

When a st at ion sen ds a call set up r equest t o it s local sw it ch , t he in gr ess sw it ch r efer en ces t h e PNNI r out ing t ab le t o d et er m in e a p at h bet w een t he sour ce and t h e int ended dest inat ion t hat Pub lish er: Cisco Press m eet s t he QoS r eq uirem ent s specified b y t he sour ce. The sw it ch at t ach ed t o t he sour ce t h en Pub Dat e: Sep tem ber 1 1, 2 003 bu ild s a list d ef ining each sw it ch h op t o supp ort t he cir cuit t o t he dest in at ion. This is called t he I SBN: 58 705 -1 19 -2 design at ed t1-r ansit list ( DTL) . Pages: 11 28

VCI = 18 is r eser ved for PNNI .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Integrated Local Management Interface I nt egr at ed Local Manag em ent I nt er face ( I LMI ) en ables devices t o d et er m ine st at us of com ponent s at t h e ot her end of a p hy sical link an d t o negot iat e a com mon set of op er at ional par am et er s t o ensur e int er operab ilit y . I LMI oper at es over a reserv ed VCC of VPI = X, VCI = 16 . •

Table of Content s

•Adm inist r at orI ndex s m ay en able or d isable I LMI at w ill, b ut it is hig hly r ecom m en ded t o enable it . IDoing nt e rn etso w orallow k ing Te s H a tndbook , Four th tEdit s tchnologie h e devices o d et er m ine h e ion high est UNI int er f ace lev el t o op er at e ( 3 .0 , 3. 1, 4. 0) , UNI vs. NNI , as w ell as n um er ous ot her it ems. Fur t h er m or e, I LMI allow s dev ices t o sh are By Cisco Systems, Inc. inf orm at ion such as NSAP add resses, p eer int er face n ames, and I P ad dr esses. Wit hout I LMI , m any of t h ese p aram et ers mu st be m an ually con figu r ed for t he ATM at t ached devices t o op er at e Pub lish er: Cisco Press corr ect ly. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

NO TE The VCI v alu es of 0 t hr ough 31 ar e r eser ved and should not be u sed for user t raf fic. Thr ee fr equent ly en cou nt er ed VCI v alues ar e show n in Table 3 1- 1. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Tab. le 3 1 - 1 . Com m onl y Use d VCI V al ue s nov ice t o ex pert New erion s include cov erag e of im por t ant t opics like VoI P and EAP V CI chapt Funct Cov e of cut tfing ologies optitical 5 erag Signaling romedge an edt echn ge dev ice t olik it se sw ch (ninetgrwor essk ing sw itand ch ) st or age 16 h ored I LMIbyforCisco link Sy p arstamet ges Aut ems,erw exchan or ldw ide leader in net w or king f or t he I n t er n et . f or ATM r ou t in g book , Four t h Ed it ion , is a com pr ehensive refer ence t hat I n t ern18 et w orPNNI k in g Tech nologies Hand enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

LAN Emulation LAN Em ulat ion ( LANE) is a st andar d def in ed by t he ATM Foru m t hat giv es t o st at ions at t ached v ia ATM t he sam e capabilit ies t hat t hey nor m ally obt ain fr om legacy LANs, such as Et h er n et and Tok en Rin g. As t h e nam e sug gest s, t he f unct ion of t he LANE p rot ocol is t o em ulat e a LAN on t op •of an ATM n et Table s wor kof. Content Specifically , t h e LANE pr ot ocol d ef ines m echan ism s f or emu lat in g eit h er an •I EEE 8 02. 3 Et I ndex h er net or an 802 .5 Tok en Rin g LAN. The cu rr ent LANE pr ot ocol does n ot def in e a Isep nt e arat rn et weoren k ing chnologie s H FDDI a ndbook FourIthpack Edit ion capTe sulat ion f or . ( ,FDD et s mu st be m ap ped in t o eit her Et h er n et or Tok en Ring - emu lat ed LANs [ ELANs] b y using exist ing t r anslat ional b rid ging t ech niques. ) Fast Et hern et By Cisco Systems, Inc. ( 10 0BaseT) and I EEE 8 02. 12 ( 1 00VG- An yLAN) b ot h can be m ap ped u nchang ed b ecause t h ey u se t he Pub sam e p ack et f or mat s. Figur e 31 - 11 com par es a p hy sical LAN and an ELAN. lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 3 1 -1 1 . ATM Ne t w or k s Can Em u la t e a Phy sica l LAN

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing The LANE pr otMast ocol er defines ice cep int er f orologies, hig her- an layderdevices ( t hat is, net w k layer p rot ocols t echnologies. t he t era mser s, vcon t s,f ace t echn used inort oday ' s )net w ork ing tindu hat st isryident ical t o t hat of exist Datwaorsen oss olog t he ies ATM or k is encapsulat ed ent in t. he . Lear n how t o incor poring at eLANs. int er net kintgacr t echn in tnet o awLAN/ WAN env ir onm app riat e itLAN MAC et fed ormchapt at . Sim ly put , t he p rot ocols ak ewan n et w or k look Comrop plet ew h new anpdack u pdat er spon secur it y ,LANE st or age, opt icalmnet or kATM in g, scalabilit y, and behav an Et is hera net Token eiterone uch fastare er tessen han an speed,e t lik h ise book comorplet e an dRing u p- tLAN—alb o- d at e r ef enceoper t o tat heing t opmics t hat t ialact t oual all Et hw eror n et Rin g LAN net w or k . of ex pert ise. net kinor g pTok rofen essionals, r egar dless IReader t is im spor t t oain not h at er LANE d oes at of t emLAN p t t and o emWAN u lat entet hew act ocol ofe t he w tillanobt a eg treat un der st annot ding or kual ing,MAC p ar t pr icuotlar ly t h specif cer ned ( t hat CSMA/ CD her net passing format I EEE ) . ided LANEon har dwic arLAN e, prcon ot ocols, and ser vis, ices inv olv edfor . FuEt ndam entor al t ok echennology inf or ion 802 is pr.5ov raeq es rno icat ionals sy t o sthem igher - layer p rot ocols t o en t h eir op er at ion aniew ATM b ruir oad angmeodif of int egr s and serv ices, in clud ingable det ailed descr ipt ionover s, rev quest ions net w or h e LANE ser v iceand p r esent t h e same er face of fex MAC pr ot t o en suk. re Because con cept tcomp r eh en sion r et enst ion, and adser ditvice ionalintr esou r ces orist fuing rt her st udy . ocols tCov o net w ork er ext dr ivend er sed ( such ant oNDI S- nor ODIk- ing like concep d riv er tint face) , no ar e r equir ed erag e islay also n ot as only new et wor s, er but also t o ch oldanges er , legacy in t hose er s.in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich syst em s, drprivovid pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t hProtocol eir net w ork Architecture s. The LANE The b asic fun ct ion of t h e LANE pr ot ocol is t o resolve MAC ad dr esses t o ATM add resses. Th e goal is t o resolve su ch add ress m appin gs so t h at LANE end sy st em s can set up dir ect con nect ion s bet w een t h em selv es and t hen for w ar d dat a. Th e LANE pr ot ocol is deploy ed in t w o t yp es of ATMat t ached eq uipm ent : ATM n et w or k int er face car ds ( NI Cs) and int er net w ork ing and LAN sw it chin g

equipm ent . ATM NI Cs imp lem ent t he LANE p rot ocol and int erf ace t o t h e ATM net w ork but pr esent t he cur r ent LAN ser v ice int er face t o t he higher - lev el pr ot ocol d riv ers wit h in t h e at t ached en d sy st em . The net w or k layer p rot ocols on t h e en d sy st em con t inue t o com mu nicat e as if t hey w er e on a k now n LAN by u sing k now n pr oced ur es. How ev er , t h ey are cap able of using t he v ast ly gr eat er ban dw idt h of ATM net w ork s. •

Table of Content s The second class of net w or k gear t o im plem ent LANE consist s of ATM- at t ached LAN sw it ch es and •r out er s. These I ndex devices, t oget her w it h direct ly at t ached ATM h ost s eq uipp ed w it h ATM NI Cs, ar e Iused nt e rn et orov k ing H a ndbook , Four th Edit t owpr ideTeachnologie vir t ual sLAN ( VLAN) serv ice ion in w h ich por t s on t h e LAN sw it ches ar e assig ned t o parCisco By t icular Systems, VLANsInc. in dependent ly of p hy sical locat ion. Figur e 31 - 12 sh ows t he LANE p rot ocol ar ch it ect u re im plem en t ed in ATM net w ork devices. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Figu r e 3 1 -1 2 . LAN E Pr ot ocol Ar chi t e ct u r e Ca n Be I m ple m en t e d in ATM Pages: 11 28 Ne t w or k D ev ices

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient NO TE decisions for t h eir net w ork s. The LANE pr ot ocol does not dir ect ly af fect ATM sw it ch es. As w it h m ost of t h e ot her ATM int er net w ork ing pr ot ocols, LANE bu ild s on t he ov erlay m odel. As such, t he LANE pr ot ocols oper at e t r anspar ent ly ov er and t hr oug h ATM sw it ch es, u sin g on ly st andar d ATM sig naling pr ocedu r es.

LANE Components The LANE pr ot ocol defines t h e oper at ion of a sin gle ELAN or VLAN. Alt houg h m u lt ip le ELANs can simu lt aneously ex ist on a sing le ATM n et w or k , an ELAN emu lat es eit her an Et hern et or a Token Ring an d consist s of t he follow in g com pon en t s: •

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•

I ndex

I nt e rn LA et wN or kEm ing ul Teat chnologie sH Four th Edit ionis i on cl ie nta ndbook ( LEC), — The LEC

an ent it y in an end syst em t hat per for m s dat a r esolut ion , and r eg ist r at ion of MAC addr esses w it h t he LAN Em u lat ion Serv er ( LES) . The LEC also pr ov ides a st and ar d LAN int er face t o high er - level p rot ocols on legacy LANs. An ATM end sy st em t h at conn ect s t o m ult iple ELANs has one LEC per ELAN. Pub lish er: Cisco Press

forSystems, w ar dingInc. , add ress By Cisco

Pub Dat e: Sep tem ber 1 1, 2 003

LES — The LES p rov ides a cent r al cont rol point for LECs t o f orw ar d r eg ist r at ion and cont r ol I SBN: 705 -1 19 -2 on e LES exist s p er ELAN. ) Th e LES m aint ains a list of MAC addr esses in inf orm1at58 ion. ( Only 11 28and t he cor r espon ding NSAP ad dr esses. tPages: he ELAN Broa dca st an d U nk n ow n Se rv e r ( BU S) — The BUS is a mu lt icast ser ver t h at is u sed t o flood un kn ow n d est inat ion ad dr ess t r af fic and t o for w ar d m u lt icast an d br oadcast t r aff ic t o client s w it hin a par t icular ELAN. Each LEC is associat ed w it h only one BUS p er ELAN.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of LA N Em ul at i on Conf ig ura t i on Ser ve r ( LECS) — The LECS m aint ain s a d at abase of LECs essent ial an d cu t t ing- edg e t ech nologies. and t h e ELANs t o w hich t hey belong. This ser v er accept s quer ies f r om LECs and r esp onds w it h t he ap pr opr iat e ELAN ident ifier —nam ely, t he ATM addr ess of t he LES t hat ser ves t h e app LECS per inist r att iv d omain serprv es all ELANs it hin hat f rom Con rop ciseriat oveerELAN. v iew s One of t echn olog iesadm essen t ial o en et wor k ing ofession als atwall levt els, dom ain.t o ex pert . nov ice BecauNew se sing le ser er com pon t s lack redu , Cisco h as ovPerand comEAP e t his shor t com ing by chapt er sv include coven erag e of im porndan t ant cy t opics like VoI im plem ent in g a pr opr iet ary solut ion called Sim ple Serv er Redu ndan cy Pr ot ocol. SSRP w ork s w it h any v Cov endor s LECs; how ever , it tr echn equirologies es t he use as ser comp erag e of cut t ing edge lik e of optCisco ical ndevices et wor k ing andv er st or age onent s. I t allow s up t o 16 LECSs per ATM LANE net w or k and an infin it e num ber of LES/ BUS pair s per ELAN. Th e Autum h ored Cisco Syastvems, or ldw idedent leader netof w or king f or tserv he Ier n t er n et . ancy: Lan e ATM For alsobyreleased endorw- ind ep en metinh od p rov iding r ed und Em ulat ion Net w ork - Net w or k I n t erf ace ( LNNI ) . Ther efor e, ser v er s f rom diff erent v en dor s can I n tov ern et w in g Tech Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat pr ide intorerk oper ablenologies r ed und ancy. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mastrer t het he t er com m s, pon con en cept st s,of t an echn ologies, an d devices used in t oday ' s net w ork ing Figur e 31 - 13 illust at es ELAN. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g rperof3essionals, r egar dless Con of ex pert Figu 1 -1 3 . An ELAN si stise. s of Cl ie nt s, Ser v er s, a nd Va r iou s

I nt er m e dia t e N od es

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

LAN Emulation Connection Types The Ph ase 1 LANE en t it ies com m unicat e w it h each ot her b y using a series of ATM VCCs. LECs m aint ain separ at e con nect ion s for d at a t r an sm ission and cont r ol t r af fic. The LANE dat a The u pdat ed ar edit iona-ofdirt he est - selling all- inoneVCC, net w and ork ing r eficast erence p rov cover age of connect ions e dat ectbVCC, m u lt icast send m ult for w ar dides VCC. essent ial an d cu t t ing- edg e t ech nologies. Dat a- d irect VCC is a bidir ect ion al point - t o- point VCC set up bet w een t w o LECs t hat w ant t o exchan ge d at a. Tw o LECs t yp ically use t h e sam e d at a- dir ect VCC t o car r y all pack et s bet w een Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom t hem r at h er t han opening a new VCC for each MAC addr ess pair . This t echniq ue conserv es nov ice t o ex pert . connect ion resour ces an d con nect ion set up lat en cy . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Mu lt icast send VCC is a b idirect ional p oint - t o- p oint VCC set u p by t he LEC t o t he BUS. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Mu lt icast f or war d VCC is a unidir ect ion al VCC set up t o t he LEC fr om t h e BUS. I t t y pically is a point - t o- m ult ipoint connect ion, w it h each LEC as a leaf. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Figur e 31 - 14 sh ows t he LANE d at a conn ect ions. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Figu -1 4an . LAN E ed D at a Conn ct i onit ys, Use a Se ie snet ofw VCLs o Lin k y,a Com plet er e w it3h1new d u pdat chapt er s one secur st or age, optrical or k in g, tscalabilit LAN Sw it ch an d ATM H ost s and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Con t rol connect ions include con figu rat ion - dir ect VCC, cont rol- d ir ect VCC, and cont r ol- dist r ibut e VCC. Conf igur at ion- d irect VCC is a bidir ect ion al point - t o- point VCC set up by t he LEC t o t h e LECS. Coned t r oldirion ect of VCC bid ir ect ion al inVCC upw ork b y ing t he rLEC t o t h ep LES. Cont rol- dage ist r of ibu t e The u pdat edit t heisb aest - selling alloneset net ef erence rov ides cover VCC is a unidir ect ion al VCC set up f rom t he LES b ack t o t h e LEC ( t h is is t y pically a point t oessent ial an d cu t t ing- edg e t ech nologies. m ult ipoint connect ion) . Figur e 31 - 15 illust r at es LANE cont r ol conn ect ions. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Figu r e 3 1 -1 5 . LAN E Cont r ol Conn ect ion s Lin k t he LES, LECS, LAN New chapt er s include cov erag e ofi tim opics like VoI P and EAP Sw chpor , at ant nd tATM Host Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

LANE Operation The op er at ion of a LANE sy st em and comp onent s is b est und er st ood by ex aminin g t hese st ag es of LEC op er at ion: per for m ing init ializat ion an d conf igur at ion, joining an d r egist er ing w it h t he LES, fin ding and in g t he • Tablejoin of Content s BUS, and per for m ing dat a t r ansfer . •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Initialization and Configuration By Cisco Systems, Inc. Upon init ializat ion , an LEC f inds t h e LECS t o obt ain r eq uir ed conf igur at ion infor m at ion. I t begins Pub lish er: Cisco Press t his p r ocess w hen t he LEC obt ains it s own ATM add ress, w hich t y pically occu rs t hr ough add r ess Pub Dat e: Sep tem ber 1 1, 2 003 r eg ist r at ion. I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 The LEC m ust t h en d et er m in e t he locat ion of t he LECS. To do t his, t h e LEC f irst mu st locat e t he LECS b y one of t h e follow ing m et hods: b y using a d ef ined I LMI pr ocedur e t o det erm ine t he LECS add ress, by u sing a w ell- k now n LECS add r ess, or b y using a w ell- k now n per m anent con nect ion t o t he LECS ( VPI = 0 , VCI = 17) . ( The w ell- kn own p er m anent con nect ion is n ot com m only used. )

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Aft er t he LEC discov er s t he LECS's NSAP, t he LEC set s up a conf igur at ion- d ir ect VCC t o t he LECS essent ial an d cu t t ing- edg e t ech nologies. and sends an LE_CONFI GURE_ REQUEST m essage. I f a m at chin g ent r y is f oun d, t h e LECS r et ur ns a LE_CONFI GURE_RESPONSE message t o t he LEC w it h t h e config ur at ion in for m at ion t h at it r eq uirCon es tcise o conn ect t o sit soft ar get olog ELAN, clu ding g: ATM ad dr ess e LES, t y pe of ov er v iew t echn iesinessen t ialt he t o nfollow et worin k ing pr ofession alsofatt hall lev els, f rom LAN being ed, .m axim um p ack et size on t he ELAN, an d ELAN nam e ( a t ex t st r ing f or nov iceem t oulat ex pert display p ur poses) . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag of cut t ing edge t echn Joining andeRegistering with theologies LES lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . When an LEC j oin s t he LES and r eg ist er s it s ow n ATM an d MAC ad dr esses, it does so b y follow ing tI hr ee st n t ern eteps: w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing 1 . Aft er t he LEC obt ains t h e LES add ress, t he LEC opt ionally clears t he connect ion t o t h e indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . LECS, set s up t he con t r ol- d irect VCC t o t he LES, and send s an LE_ JOI N_REQUEST m essage Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, on t hat VCC. This allow s t he LEC t o r egist er it s ow n MAC and ATM ad dr esses w it h t h e LES and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all and ( op t ion ally ) any ot h er MAC ad dr esses for wh ich it is pr oxy ing . This inf or mat ion is net w or kin g p rof essionals, r egar dless of ex pert ise. m aint ained so t hat no t w o LECs w ill r egist er t he sam e MAC or ATM addr ess. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e 2 .dwAft eceipt of tand he LE_ N_REQUEST m essage, h e t LES checksinf w it t heion LECS ia ided it s opon en har ar er e, rpr ot ocols, serJOI v ices inv olv ed . Fu ndam entt al ech nology orhmat is prv ov connect ion, v erif ies t he r equest , and conf ir m s t h e client ' s m emb er ship. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . 3 . erag Upon ccessf v eredif icat , t he t he LECconcep as a leaf of italso s point t o-er m,ult ipoint Cov e issualso extulend n otion only t o LES new adds n et wor k ing t s, but t o -old legacy cont r oldist r ib ut e VCC an d issues t he LEC a su ccessf ul LE_JOI N_ RESPONSE m essage hat syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in wthich cont ains a un iq ue LAN Em ulat ion client I D ( LECI D ) . The LECI D is used b y t he LEC t o filt pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease er br doadcast omiciency, t he BUS. pr oduitcts ivow it yn an im pr ovs efreff help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Finding and Joining the BUS Aft er t he LEC has successfully j oined t he LECS, it s f irst t ask is t o f ind t he BUS's ATM ad dr ess t o

join t h e br oadcast gr ou p an d b ecom e a mem ber of t h e em u lat ed LAN. First , t he LEC cr eat es an LE_ARP_REQUEST pack et w it h t he MAC ad dr ess 0 xFFFFFFFF. Then t he LEC sends t his special LE_ ARP p acket on t h e cont r ol- dir ect VCC t o t h e LES. The LES r ecognizes t hat t he LEC is look in g for t h e BUS and r esp onds w it h t he BUS' s ATM ad dr ess on t h e cont r oldist r ibut e VCC. When t he LEC has t he BUS's ATM add ress, it j oins t he BUS by f ir st cr eat ing a signaling p ack et • Table of Content s w it h t he BUS's ATM add r ess and set t ing up a m u lt icast - sen d VCC wit h t h e BUS. Upon r eceipt of •t he sign alin gI ndex requ est , t he BUS add s t he LEC as a leaf on it s poin t - t o- m ult ipoint m ult icast for w ar d IVCC. nt e rn et w orLEC k ing is Te chnologie H ab ndbook th Editand ion is r eady f or dat a t r ansfer . The now a msem er of ,t Four he ELAN By Cisco Systems, Inc.

Data PubTransfer lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

The f inal I SBN: st at 1- e, 58 705 d at-1a19t r-2ansf er , in volv es resolving t h e ATM addr ess of t he dest inat ion LEC an d act ualPages: d at a 11 t ran 28 sf er , wh ich m ight include t he f lu sh p rocedur e. When a LEC has a dat a packet t o send t o an u nk now n dest in at ion MAC ad dr ess, it mu st discover t he ATM ad dr ess of t h e dest in at ion LEC t hr ou gh w hich t h e par t icular add ress can b e r eached. To accom p lish t his, t he LEC f ir st send s t he d at a f ram e t o t he BUS ( via t he m ult icast send VCC) for dist r ibut ion t o all LECs on t he ELAN v ia t h e m ult icast for w ar d VCC. Th is is done becau se The u pdat ofress t he m b est - selling all- ining net r ef erence idesarcover of of r esolv ing ted he edit ATMion add ight t ak e som e t one im e, net andw ork m any w ork p rpotrov ocols e int age oler ant essent ial an d cu t t ingedg e t ech nologies. delay s. The LEC t hen sen ds a LAN Emu lat ion Ad dr ess Resolut ion Pr ot ocol Request ( LE_ARP_Requ est ) Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom cont r ol f ram e t o t he LES via a cont r ol- dir ect VCC. nov ice t o ex pert . I f t he LES k now s t he answ er, it r esp onds wit h t h e ATM ad dr ess of t h e LEC t hat ow n s t he MAC New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP add ress in quest ion. I f t he LES does not kn ow t h e answ er , it floods t he LE_ARP_REQUEST t o som eCov or all LECs u nder par allel t he flooding t h eand act ual at a f ram e, b ut ov er erag e of( cut t ingr ules edget hat t echn ologies lik eBUS's opt ical n et worof k ing st ordage cont r ol- dir ect and cont r ol- dist rib ut e VCCs inst ead of t he m ult icast sen d or m ult icast for w ar d VCCs Aut used b y t he BUS) . Sy I f st brems, idge/ w sw ching w itnet h LEC soft wf or ar et he parI tnicipat h ored by Cisco oritldw ide devices leader in w or king t er n eting . in t he ELAN exist , t h ey respond t o t he LE_ARP_REQUEST if t hey serv ice t he LAN dev ice wit h t h e r eq uest ed MAC is nologies called a pr ox y book ser v ice. I n t ernadd et wress. or k inThis g Tech Hand , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing It echnologies. n t he case of Mast act ual at at er t r ansf , ifcep ant s, LE_ARP messag an e is eceived,used t he in LEC set s' su net p a wdat er dt he m s, er con t echn ologies, d rdevices t oday orka-ing dir ect VCC t o t he dest inat ion LEC an d u ses t h is for dat a t ran sf er r at her t han t h e BUS pat h indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm. ent . Befor e itecan t his,anhow ev er ed , t hchapt e LECermsigh n eedittyo, ustse he LANE f lush w hich y, Com plet w it hdonew d u pdat on t secur or tage, opt ical netpwrocedur or k in g,e,scalabilit ensur es t hat all pack et s pr ev iously sen t t o t he BUS w er e deliver ed t o t he d est inat ion pr ior and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ialt ot ot he all use of t h e dat ad ir ect VCC. I n t he f lu sh p rocedur e, a con t r ol fr am e is sent d ow n t he f ir st net w or kin g p rof essionals, r egar dless of ex pert ise. t r ansm ission pat h follow ing t he last packet . Th e LEC t h en w ait s u nt il t h e dest inat ion ackn owsledg receip t h eerflush pack befor u sinand g t h WAN e second atkhing, t o sen packet Reader w illes obt ain at gofreat un der st anetding ofeLAN n et wpor p ardt icu lar lys.t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Multiprotocol over ATM Mu lt ip rot ocol over ATM ( MPOA) pr ov id es a m et hod of t r ansm it t in g dat a b et ween ELANs w it h out needing t o con t inuou sly p ass t hr ough a rou t er . Nor m ally, dat a passes t h rou gh at least on e r out er t o get f r om one ELAN t o anot h er . Th is is nor m al per - hop r out ing as ex perienced in LAN •env iron ment s. Table of Content s er , enab les devices in d if fer ent ELANs t o comm un icat e wit h out MPOA, h owev •needing t o t rav I ndex el hop b y hop. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Figur e 31 - 16 illust By Cisco Systems, Inc.r at es t he pr ocess w it hout MPOA in par t A and w it h MPOA in par t B. Wit h MPOA- enab led dev ices, only t h e fir st f ew fr am es bet w een dev ices pass t h r ough r out er s. This is called t he defau lt pat h . Th e fr am es pass fr om ELAN t o ELAN t h rou gh appr opr iat e r out er s. Aft er a Pub lish er: Cisco Press few fr am es f ollow t he default pat h , t he MPOA d ev ices d iscov er t he NSAP addr ess of t he ot h er tem ber 1 1, 2 003 dev Pub ice Dat an e: d tSep hen b uild a dir ect connect ion called t h e shor t cut f or t h e subsequent fr am es in t h e I SBN: 158 705 -1 19 -2 flow . Pages: 11 28

Figu r e 3 1 -1 6 . A Com pa r ison of I n t e r -ELAN Com m u ni ca t ion s W it h out ( Pa r t A) a nd w it h ( Pa r t B ) M POA The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. [ View full size im age]

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient The edg e dev ices t h at gener at e t h e ATM t raf fic ar e called m ult ipr ot ocol clien t s ( MPC) and m ay be decisions for t h eir net w ork s. an ATM- at t ached w ork st at ion, or a r out er . The in t er- ELAN r ou t er s ar e called m ult ipr ot ocol ser v ers ( MPS) an d assist t he MPCs in discover in g how t o bu ild a sh ort cut . MPSs ar e alw ay s r out er s. This r educes t he load on r out er s because t he r ou t er s d o not need t o sust ain t he cont in uous f low bet w een dev ices. Fur t her m ore, MPOA can redu ce t he n um ber of ATM sw it ches supp ort in g a

connect ion, f r eeing up v irt u al circuit s and sw it ch r esour ces in t h e ATM n et wor k . Figur e 31 - 16 illust rat es t he connect ion befor e and af t er t he shor t cut is est ab lished. Not e t h at MPOA does n ot r eplace LANE. I n f act , MPOA requ ires LANE v ersion 2.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

Nam e t he f our com pon en t s of LANE.

2:

I ndexLANE comp onent main t ains an ATM ARP t ab le? Which

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Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 :Systems, WhichInc. LANE By Cisco 4:

comp onent main t ains policy for ELAN mem ber sh ip?

List t w o fu nct ions of PNNI .

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

Which field in t h e ATM h ead er ch eck s t he h ead er int egr it y?

I SBN: 1- 58 705 -1 19 -2 11 28 is t h e pr imar y d if fer ence bet w een t he UNI h ead er and t he NNI h ead er ? 6Pages: : What

7:

Which adapt at ion m ode is most appr opr iat e t o int er con nect T1 sig nals f rom PBXs ov er ATM?

: ed Which ionb m is most equent ly w imork plem f or dat a tides r anspor t over The u 8pdat edit adapt ion of at t he estode - selling all- fr inone net ing en r eft ed erence p rov cover age of ATM? essent ial an d cu t t ing- edg e t ech nologies. 9 : What VCI value is reser v ed f or call set u p requ est s f r om an ATM edg e device? Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom 1 nov 0 : ice What t o ex ATM pertpr . ot ocol sim p lif ies t he ATM adm inist rat or' s life b y aut om at ically en su rin g t hat cer t ain ATM par amet er s ar e comp at ible bet w een t w o devices con nect ed t o t he New sam chapt include cov erag e of im por t ant t opics like VoI P and EAP e er linsk? e of cut pr t ing edgecomm t echnuologies opt et wor k ing andswstitor age 1 Cov 1 : erag What ATM ot ocol nicat es lik execlu sivical ely nbet w een ATM ches? Syfer st ems, orween ldw ide leader net w or king f or t he I n t er n et . 1 Aut 2 : h ored Descrby ibeCisco t he dif en ce bwet PVC an d in SVC. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat 1 3 : What is t h e pur pose of t h e adapt at ion lay er? enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing 1 4 : What adv ant ag e is t her e t o im p lem ent ing MPOA? indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Clark , Kenn ed y, and Kev in Hamilt on . CCI E Pr ofessional Develop m en t : Cisco LAN Sw it ching . I ndian apolis: Cisco Pr ess, 19 99. •

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I ndex

•I nt Ginsbur Dav id . ATM: sSolu t ions ,for Ent prion ise I nt ern et wor k in g . Bost on: Add ison- Wesley e rn et w or g, k ing Te chnologie H a ndbook Four th er Edit Pub lishin g Co, 19 96. By Cisco Systems, Inc.

• McD Pub lish ysan, er: Cisco DavPress id E., and Dar r en L. Spohn . ATM Theory and Applicat ion . New Yor k : McGr aw - Hill, 19 98 Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 11 28 • ht t p: Pages: / / www . at mf or um . com f or ATM st andar ds docum en t

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 32. MPLS Obj e ct i ve s • •

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Under st and t he ad van t ages of MPLS. I ndex

I nt e rn Lear et w ornk ing chnologie s Hsa of ndbook , Four th ion. t heTecom ponent an MPLS syEdit st em By Cisco Systems, Inc.

Com par e an d cont rast MPLS and hop- by - hop rou t ing. Pub lish er: Cisco Press

Descr ibe t he t w o met hod s of label dist r ibut ion .

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 705p-1 -2 Ex plain1- 58 t he ur19pose of MPLS t r aff ic engineerin g. Pages: 11 28

I n a t y pical r out er - based n et w or k , Lay er 3 dat ag ram s p ass fr om a sou rce t o a d est inat ion on a hop - by - hop basis. Tr ansit r out er s evaluat e each dat ag ram ' s Lay er 3 header and per for m a r out ing t ab le look up t o det erm ine t he nex t h op t ow ard t h e dest in at ion. Alt hou gh some rou t er s im plem ent har dw ar e and soft war e sw it ching t ech niqu es ( f or ex amp le, Cisco Ex pr ess For w ard in g [ CEF] ) t o acceler at e t h e evaluat ion pr ocess by cr eat ing h ig h- speed cache ent r ies, t hese met h ods The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of r ely on t h e Lay er 3 rou t ing pr ot ocol t o det er m ine t h e pat h t o t he d est inat ion . essent ial an d cu t t ing- edg e t ech nologies. Unfor t u nat ely, rou t ing pr ot ocols hav e lit t le, if an y, visibilit y int o t he net w or k 's Layer 2 char act er cise ist ics, icular in regar t o essen qualittyialoft oserv and lin k load. anges Con ovperart v iew s oflyt echn ologdies n etice wor( QoS) k ing pr ofession als atRapid all levch els, f romin t he t yp e ( and qu ant it y ) of t r af fic h andled b y t he I n t er n et and t he ex plosion in t he num ber of nov ice t o ex pert . I nt er net u ser s is pu t t ing an unp reced en t ed st r ain on t h e I nt er net 's in fr ast ru ct ur e. This pr essu re m andat es chapt n ew ter r aff ic- m anag emerag ent esolu t ions. rot ocol elPsw it ching New s include cov of im por t Mult ant tip opics likelab VoI and EAP ( MPLS) an d it s pr edecessor, t ag sw it ching , ar e int ended t o resolve m any of t he challenges f acing t h e evolv ing I nt er net d heighspeed at a com m unicat ions gener Covan erag of cut t ing dedge t echn ologies lik einopt ical al. n et wor k ing and st or age To m eet ese nby ewCisco deman MPLS chang es leader t he h op- hop par adf or ig m byI nlet Aut ht hored Sy ds, st ems, w or ldw ide in by net w or king t he t ert ing n et .edge rou t ers specif y pat h s in t he net w or k based on a v ariet y of user - defined cr it er ia, inclu ding QoS rI neqt ern uir em et went or ksinan g dTech t henologies ap plicat Hand ion s' book b andw , Four idt h tneeds. h Ed it ion I n, ot isher a com w orprds, ehensive pat h select referion ence in a t hat r out erenables only n et w net orw k or can kinnow g p r ofessionals t ake in t o account t o un derst Lay er and2 an at tdr ibim utplem es. This en t cont solutem ionpor letar s yI nint t ern er et netser w ork v ice ing t echnologies. pr ov iders ( I SPs) Mast and er tlarg he teerent m s, erp con rise cep n et t s,wtor echn k s deploy ologies,a an unif d ied devices Lay erused 3 infr in ast t oday r uct' ur s net e t hwat orkcan ing indu st supp ort ry .r eq Lear uirnem how ent st ot hat incorinpor t h at e past e int er w er net e wsupp or kin ort g ed t echn only olog w ities h tin het oLay a LAN/ er 2 WAN b ack bon enveir(onm suchent as. a Com plet Fram e Relay e w it h or new ATMan b ack d u pdat bon e) ed. chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Inet n essen ce, e essionals, MPLS t ech nology comof bines t h eise. r ich ness of I P rou t ing and t he sim plicit y of hopw or kin g pt hrof r egar dless ex pert by - hop label sw it ching of Fram e Relay or ATM t o pr ovid e seam less in t eg rat ion of conn ect ionReader or ien t eds w Layer ill obt2ain for a w ar g reat dingerwun it hder t he st an conn ding ectof ionless LAN and I P wWAN or ld. nBecause et w or k ing, of tpheir ar t icu du lar al ly natt h ue re ( t hey har dw oper atar e e, on pr t he ot ocols, I P layer and and seron v ices t he inv labolv el-ed sw. itFu ching ndam layer ent al ) , tMPLS ech nology d ev ices inf or ar mat e called ion isLabel pr ov ided Sw it ch on a b r toad Rou er s (r LSRs) ang e of . int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Based one Cisco's p rop riet swtitoching ocol, the I ETF has d ef also ined tMPLS a v endor Cov erag is also ext end edarnyott agonly new npretotwor k ing concep t s, but o old eras, legacy independ p rot o p rot in wcomm on lyenmaj or dif fersen is in syst em s, en pr tovid inocol. g a mTh oree trwealist ic ocols pict urheave of tmu he ch realor ld non. et wThe or k ing vir onm ent ince w hich tpr heof det ails of oper t he pr u sed adj facen t MPLS d ev ices, ing w or kwadm inist r at ors essionals atot e.ocol Tools andbet guwideen elines or opt im izing syst emgiv per fornet m ance ill incr ease an oppor y df or miciency, ig r at ionhelp f r om it chingmnet or kse t in o st and ard, s-cost based MPLS pr odu ct ivtituynitan imgr pradu ov ealeff ingt agt hesw r eader akew mor t elligent - eff icient net w or ks. for t h eir net w ork s. decisions

MPLS Terminology MPLS uses a n um ber of new t er m s. Her e ar e t h e m ost sig nificant : La be l he Table ad er of — Content A header s cr eat ed by an edg e LSR and used by LSRs t o f or w ard pack et s. The h ead er for m at v ar ies based on t he n et wor k m edia t yp e. I n an ATM net w ork , t h e label is I ndex in Te t he VPI / VCI of, Four each cell header. I n all ot h er en vir onm ent s ( for I nt e rn placed et w or k ing chnologie s H afields ndbook th ATM Edit ion exam ple, LANs or point t opoint link s) , t he h ead er is a " shim " locat ed bet w een t he Layer 2 By Cisco Systems, Inc. and Lay er 3 header s, as show n in Figur e 32 - 1. Th e label header can con t ain on e label or a st ack of labels. • •

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Figu r e 3 2 -1 . Posi t i on of t he M PLS Lab el He a der in a La y er 2 Fr a m e

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New erar s include cov erag of Ba im se por (t ant t opics VoI and La bechapt l For w din g I nfor m a t ieon LFI B) — Alike t able crPeat ed EAP b y an LSR- capab le device t hat ind icat es w her e and how t o f or war d fr am es w it h sp ecific label v alues. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age LSR— A dev ice, such as a sw it ch or r out er, t hat for w ar ds labeled ent it ies based on t he Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . label v alue. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Edg e LSR— A dev ice t hat in it ially ad ds t h e label t o or ult im at ely r em oves t h e label fr om enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t he packet . An edge LSR has som e int er faces con nect ed t o ot her LSRs and some in t erf aces t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing connect ed t o non - MPLS- enab led dev ices ( f or exam ple, I P h ost s) . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e wLSR— it h newA an d ice u pdat er sswit on ches securlabeled it y , st orpage, opt ical neton w or k inlabel g, scalabilit Core dev t hatedp rchapt im ar ily ack et s based t he v alue y, and speed, t h is book is a com plet e an d u pt od at e r ef er ence t o t he t op ics t hat are essen t ial t o all pr esent in t he label h ead er . All in t erf aces of a core LSR are con nect ed t o ot her LSRs. net w or kin g p rof essionals, r egar dless of ex pert ise. La be l- sw i t ch ed — When an LSR m ak es a f orw ar din g d ecision b ased on t he v alue of a label Reader w illMPLS obt ain a ger reat dere/stcell. an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e in st he h ead ofera un fr am har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy s )and servpat ices, descr ipt ionLSRs s, revbet iewwquest La be l- Sw it che d Pa t hst( em LSP — The h din efclud ineding b y det t heailed lab els t hr ough een aions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . pair of edg e LSRs. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst emadd s, pr ovid g a m are or e defined r ealist ic for pictMPLS ur e ofopt he realld nATM et w or ingonm en vir A f ew it ion alint er ms er at ion w inort he enkvir entonm : ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient La befor l Vtirh teir ua net l Ciwrcui decisions ork ts.( LV C) — An LSP t h rou gh an I P+ ATM ( MPLS- en abled ATM) syst em . La be l Sw it ch Con t rol le r ( LSC) — An LSR at t ach ed t o an ATM sw it ch t h at com m unicat es w it h t he ATM swit ch t o pr ovide and pr ov ision LVC cross- connect s in t he ATM sw it ch. La be l D ist ri but i on Pr ot ocol ( LD P) — A set of m essages def in ed t o dist r ib ut e lab el inf orm at ion am ong LSRs.

Xm plsATM — The v irt u al int er face b et w een an ATM swit ch and an LSC.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

MPLS Operations This sect ion illust r at es t he p assage of a fr am e t h rou gh an MPLS sy st em t o h ighligh t t h e fu nct ion of sev eral key MPLS com ponent s. Specif ically , it illust r at es MPLS t hr oug h a fr am e- based inf rast r uct ur e as opposed t o a cell- based ( ATM) syst em . •

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•I n Figur e 32 - 2, I ndex a ser ies of LSRs ( edg e and cor e) int er con nect , for m ing a ph ysical pat h b et w een It w nt o e rn et w or k ing s H a ndbook , Four element s, Te Stchnologie at ion A and St at ion B. th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press

Figu r e 3 2 -2 . Ser i es of I nt er conn ect ed LSRs

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

[ View full size im age]

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all The Et her net f r ame car r yin g an I P d at agr am g en er at ed by St at ion A f ollow s t he st and ard net w or kin g p rof essionals, r egar dless of ex pert ise. Et h er n et for m at w it h a nor mal Lay er 2 header follow ed b y a Layer 3 header . Becau se t he dest inatsion ess ar esides a der dif fer ending t n et w k , Stand at ion A t ar get s tkhe Lay er t icu 2 header Reader w illaddr obt ain g reat erinun st an oforLAN WAN n et w or ing, p ar lar ly t hteo it s defau lt g at ew ay ( R1) . I n t his case, t he d ef ault gat ew ay also ser v es as t he edg e LSR ( ing ress on har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided side) . The in gr ess LSR r efer en ces it s in t er nal I P sw it ch in g t able ( For war d in g I n for m at ion Base a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions [t oFI en B] su ) and d et er m in es t hat it needs t o for w ar d t he I P d at agr am t h rou gh int er face S1 t ow ard re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . the nex LSR. Cov terag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Fur t her mor e, t h e FI B en t r y for n et wor k 1 72. 16 . 1. 0/ 24 in t he in gr ess LSR ind icat es t h at t he pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease ingr ess LSR m ust in ser t a label bet w een t h e Lay er 2 an d Lay er 3 h ead er s t o indicat e w hat pat h pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient t he fr am e should t ak e on it s w ay t o St at ion B. Th e ingr ess LSR, t her ef ore, in ser t s an MPLS decisions for t h eir net w ork s. header b et w een t he Point - t o- Poin t Pr ot ocol ( PPP) Lay er 2 header and t he I P header ( t h is pr ocess is called label im posit ion) an d for w ard s t he lab eled packet t ow ard R2. Rou t er 2 look s at t he fr am e ent er ing por t 1 an d d et er m ines t hat a label is em bedd ed bet w een Layer s 2 and 3 based on t he in for m at ion in t h e fr am e's Layer 2 header ( f or exam p le, PPP pack et t y pe or Et her Typ e field in LAN packet s) . Th er efor e, t he rou t er t r eat s t he f ram e accor ding t o t he conf ig ur at ion in it s LFI B, w hich say s t o for w ar d t he f ram e ou t por t 2 and r ep lace t h e incom in g lab el 6 w it h out going label

11 . Each of t he sub sequ en t r out er s han dles t he f r ame in a sim ilar m anner u nt il t h e fr am e r eaches t h e egr ess LSR. The egr ess edge LSR p er f orm s t he label look up in t he sam e w ay as all t h e pr ev ious LSRs, f in ding no out g oin g lab el t o u se. I t , t herefor e, st r ips of f all label inf orm at ion ( t his is called label r em ov al) and passes a st andar d I P dat agr am encapsulat ed in an Et h er net fr am e t o St at ion B. Becau se each of t he r out er s bet w een St at ion s A an d B can sw it ch t he f ram e b ased on con t en t in t he LFI B and does not need t o per for m t he usual rou t ing oper at ion, t h e I P dat ag r am for w ar ding • Table of Content s across t he net w or k is han dled m or e eff icient ly . Fur t her mor e, t h e LSP b et ween R1 and R4 can • I ndex t ak e dif fer en t link s t han t h e ones ind icat ed in t h e I P r out in g t ab le. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

MPLS/Tag-Switching Architecture MPLS r elies on t w o p rin cipal com p onent s: f or war din g an d con t rol. The cont r ol com ponent is r espon sib le for m aint ain in g cor r ect label- for w ard ing infor m at ion am ong a gr ou p of int er con nect ed LSRs. The f orw ar din g com ponent uses labels carr ied b y pack et s and t he lab el•for w ar ding inf Table of Content s ained by an LSR t o per for m pack et f orw ar ding . Det ails abou t MPLS or mat ion m aint •for w ar ding and I ndex cont r ol mechanism s follow . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Control Component Pub lish er: Cisco Press Pub Dat e: in Sepan temMPLS ber 1 1, net 2 003w ork ru n I P rou t ing pr ot ocols on t heir cont r ol plane t o bu ild I P r ou t in g All dev ices I SBN: 158 705 -1 19 -2 t ables. I n MPLS devices t hat su ppor t I P for w ar ding ( f or exam ple, edg e LSR) , t he I P r ou t ing t ablesPages: ar e used 11 28 t o b uild I P for w ard ing t ables ( FI Bs) . I n MPLS dev ices t h at sup por t on ly lab el for w ar ding ( such as ATM sw it ches w it h MPLS fu nct ionalit y) , t he I P rou t ing FI B does not ex ist . Figur e 32 - 3 sh ows t he I P r ou t in g operat ion of t h e MPLS con t r ol plane.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Figu e t3 2 -3 . LSRs B ui ld t h e I P Rout in g Ta ble essent ial an d cu t t ingedgr e ech nologies. [ View full age] Con cise ov er v iew s of t echn olog ies essen t ialsize t o im n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Aft er t he I P r out in g t ables hav e been b uilt , MPLS labels ar e assign ed t o indiv idual en t ries in t he t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing I P r out in g t able ( indiv idual I P pr efix es) and ar e pr opagat ed t o adjacent MPLS devices t hr oug h an indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . LD P. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e NO TE har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang eMPLS of intop egreralatsy st em andarserv ices, in clud ing detder ailed descr iptPr ion rev( iew I n usual ion, labsels e n ot assigned t o Bor Gat ew ay ots, ocol BGP)quest ions t o endest su reinat conions, cept bcomp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy ecause t h e r out er alw ays reaches BGP dest in at ions t hr ou gh recur siv e . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy look up on t he BGP next hop . BGP dest in at ions, t her ef or e, can be reached t hr ough t h e syst em s, pr ovid in geda w mitorhet he r ealist pict ur e off or t he real-dest w or inat ld n ions, et w oras k ing vir onm s in w hich label associat BGPicnext hop t hose ex en plained inent t he pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease sect ion " Hier ar chical Rout in g. " pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Each MPLS dev ice u ses it s ow n local label space. Ther e is no need for globally un ique labels or cen t r alized label assig nm en t , m ak in g MPLS ex t r em ely r obust and scalable. Ev er y label assig ned by an MPLS d ev ice is en t ered as an inpu t label in it s LFI B—t he for w ard ing t able t h at is u sed for label sw it ch ing. Figur e 32 - 4 sh ows lab el assign ment and d ist r ibut ion f or an MPLS device.

Figu r e 3 2 -4 . Cont r ol Pla n e Op er a t ion s in a n LSR [ View full size im age] •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Most lab el assign ment s, bot h local and t hose m ade b y adj acent dev ices, ar e en t ered int o a t ab le calledNew t he chapt Label er I nf at ioncov Base LI of B) .im Thpor e label y t he I P next s orm include erag( e t ant tassig opicsned likebVoI P and EAP hop f or a p art icular I P pr efix is ent er ed as an ou t put label in t he local LFI B t o enable p ur e label f orw ar din g. I n devices t hat supp Cov erag ort IeP of f orcut wart ing d in g, edge such t echn a label ologies is also lik een opt t erical ed ninettwor h e FI k ing B t oand supst por or age t I P- t o- lab el for w ar ding . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. NO TE Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet TheeLIwBit h cont new ains an all d utpdat he labels ed chapt assig er sned on tsecur o an it I Py ,p st refix or age, b y topt he ical localnet LSR w orand k in g, it sscalabilit y, and speed, neighb or t h s. is book The LFI is B a cont com ain pletseonly an d tuhpe tinbou o- d atnde r ef t o-erou ence t bout ondt he labt el op m icsapping t hat are u sed essen t o t ial t o all net w or forkin w ar g dp rof labeled essionals, pack et r egar s. I nf dless or mat ofion ex pert in t he ise.LFI B is, t heref ore, alw ay s a sub set of inf orm at ion in t he LI B. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Label Protocol Cov erag Distribution e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Wit dest inat ionased r out ing, r out er m ak a fim orw ar din g dem ecision b ased on wt he Layer 3 pr ofhessionals operbat e. Tools and agu id elines f oresopt izing syst per for m ance ill incr ease dest inat ion car a p ackhelp et aning d tthe or matm ion or ede in B m ain, tcost ained y t he pr odu ct iv it y addr an d ess im pr ovr eied effin iciency, he inf r eader akest mor in tFI elligent - effbicient rdecisions out er . A rfor outt er con st rwuct it s FI B usin g in for m at ion t he r out er r eceiv es f r om r out ing pr ot ocols, h eir net orks s. such as OSPF and BGP. To su ppor t dest in at ion - based r out in g wit h MPLS, an LSR par t icip at es in r ou t in g pr ot ocols and const r uct s it s LFI B u sin g in for m at ion it r eceiv es f rom t hese pr ot ocols. I n t his w ay , it operat es m uch lik e a rou t er.

An LSR, how ever , m ust d ist r ibu t e and use allocat ed labels f or LSR peers t o cor rect ly for w ar d t he fr am e. LSRs dist r ib ut e labels u sing an LD P. A label b inding associat es a dest in at ion su bnet w it h a locally sig nificant label. ( Lab els can be locally sig nificant becau se t hey ar e r ep laced at each hop .) Whenev er an LSR discov ers a neighb or LSR, t he t w o est ablish a TCP conn ect ion t o t ran sf er label bin dings. LDP ex chang es sub net / label bin dings using one of t w o met hod s: dow n st r eam un solicit ed d ist r ibut ion or d ow nst r eam - on- deman d d ist r ibu t ion. Bot h LSRs m ust ag ree on w hich m ode t o use. •

Table of Content s

Dow nst r eam un solicit ed d ist r ibut ion d isper ses lab els if a dow nst r eam LSR need s t o est ablish a • I ndex new b inding w it h it s neighb orin g u pst r eam LSR. For ex am ple, an ed ge LSR m ay enable a new I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion int er face w it h anot her sub net . The ed ge LSR t h en ann ounces t o t he u pst ream LSR a bind ing t o By Ciscot his Systems, Inc. r each n et wor k. I n dow nst on - deman d dist ribu t ion, on t h e ot her han d, a dow nst r eam LSR sen ds a bind in g Pub lish er:r eam Cisco- Press up stPub r eam on ly if t h e up st r eam LSR r equest s it . For each r out e in it s rou t e t able, t h e LSR Dat e: Sep tem ber 1 1, 2 003 ident if ies t h e nex t h op f or t hat r out e. I t t hen issues a r equ est ( via LDP) t o t he nex t h op f or a I SBN: 1- 58 705 -1 19 -2 label bin ding for t hat rou t e. When t he n ex t hop r eceiv es t he requ est , it allocat es a label, cr eat es an en tPages: r y in 11 it s28LFI B w it h t he incom ing label set t o t he allocat ed label, and t h en r et ur ns t h e bind ing bet w een t he ( in com ing ) label an d t he r out e t o t h e LSR t hat sen t t h e or ig inal r equest . When t he LSR receiv es t he b inding inf or mat ion , it cr eat es an ent r y in it s LFI B an d set s t h e out g oing label in t he ent r y t o t he v alue r eceiv ed f rom t he n ex t hop. I n a net w ork u sin g dow n st r eam - on- dem and dist r ibut ion , t his p rocess is repeat ed r ecur sively un t il t he d est inat ion is rThe eached. u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Forwarding Component Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing

pr ofession als at all lev els, f rom nov ice t o ex pert . The f or w ard ing par adigm em ploy ed b y MPLS is based on t h e not ion of label sw apping . When an chapt er s include erag et he of sw im it por like VoI P and EAP LSR r New eceives a pack et w it h cov a label, cht ant usest opics t he label as an ind ex in it s LFI B. Each ent r y in t he LFI B consist s of an incom ing label and one or m ore su bent r ies ( of t he f orm out goin g lab el, Cov erag e ace, of cut t ing edge t echn ologies lik eion opt) .ical et sw woritkch ingfinds and an st or age out g oing int erf out goin g link - level inf or mat I f t nhe ent ry wit h t h e incom ing lab el eq ual t o t he lab el carr ied in t he packet , f or each com ponent in t he ent r y , t h e h ored by w or leader in netlabel, w or king f or t het he I n t link er n et . el inf orm at ion sw it chAut r eplaces t h eCisco labelSy instt ems, he p ack etldw w itide h t he out going r eplaces - lev ( such as t he MAC ad dr ess) in t h e packet w it h t h e out g oing lin k- lev el in for m at ion, an d f or w ard s I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat t he packet over t h e out g oin g in t er f ace. Som e MPLS d ev ices ( ed ge LSR) can receiv e I P enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing dat ag r ams, p er f orm a look up in t h e FI B, in ser t an MPLS lab el in f ron t of t h e I P dat agr am based t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing on infor m at ion st ored in t he FI B, and for w ar d t he labeled p ack et t o t he next - h op LSR. Th e indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . sw it ch in g pat hs su ppor t ed in an edge LSR are sh own in Figur e 32 - 5. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

r eer3 un 2 -5 Sw i t chof inLAN g Pa t h WAN s in naetnwEdge Reader s w ill obt ainFigu a g reat der. st an ding and or k ing, LSR p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

From t he p rev ious descript ion of t h e for w ar ding comp onent , you can mak e sever al observ at ions. First , t he for w ar ding decision is based on t he exact - m at ch algor it hm u sing a fix ed - len gt h, fair ly shor t lab el as an in dex. This enables a sim plified for w ar ding pr oced ur e, relat iv e t o lon gest - m at ch for w ar ding , t r adit ionally used at t h e net w or k layer . This, in t ur n, en ables higher f or war d in g perf or man ce ( higher p ack et s per secon d) . Th e for w ar ding pr ocedur e is sim ple enoug h t o allow a st r aigh t for w ar d h ard w are im p lem ent at ion. A •second ob serTable of Content vat ion is t h at st h e for w ar ding decision is independ en t of t h e label's f or war d in g •gr anu larit y . Th I ndex e sam e f or w ard in g alg orit h m , for ex am ple, applies t o bot h un icast an d mu lt icast : IAntuenicast rn et w orent k ing r yTewchnologie ould hav se H aandbook sing le, Four su bent th Edit r y ion ( out going label, out g oin g in t erf ace, ou t going link level inf or mat ion ) , and a mu lt icast en t ry mig ht hav e one or m or e subent ries. This illust r at es how By Cisco Systems, Inc. t he sam e f or war din g p ar adigm can be u sed in lab el sw it ching t o su ppor t diff erent r out ing fu nct ions. Pub lish er: Cisco Press

e: fSep tem 1, p 2 003 ThePub simDat ple orw arber din1 g rocedur e, t h us, is essent ially decoupled fr om t h e con t r ol comp onent of I SBN: 158 705 -1 19 -2 label sw it ch ing. New r ou t ing ( con t r ol) f unct ions can r ead ily b e deploy ed w it hou t d ist u rb ing t he for w arPages: ding par 11 28ad ig m . This m eans t h at it is not necessar y t o r eop t imize for w ard ing perf or man ce ( by mod ify ing eit h er har dw ar e or soft w ar e) as n ew rou t ing ( cont r ol p lan e) fu nct ionalit y is add ed . For exam ple, a larg e num b er of MPLS ap plicat ion s shar ing com m on LFI B ar e alr ead y su ppor t ed in Cisco rou t ers, as sh own in Figur e 32 - 6.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r e 3 2 -6 . M u lt ipl e M PLS App licat ions Sh ar i ng a Com m on LFI B Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

Label Encapsulation

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Lab el infor m at ion can be car r ied in a p ack et in a v ar iet y of w ays: a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag ext end ot onlyinser t o new et wor k ing but t o kold erer , legacy As e a is smalso all shim labed el nheader t ed nbet w een t heconcep Lay er t s, 2 an d nalso et wor lay header s ( see syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in w hich Figur e 32 - 7) pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figu r e 3 2 -7 . M PLS La be l He ade r For m at

• •

As par t Table of t he of Layer Content2s header if t h e Lay er 2 header pr ov id es adequat e sem ant ics ( such as ATM) I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

As a result , MPLS can be im plem en t ed ov er any m edia t yp e, in clu ding point - t o- point lin ks, By Cisco Systems, m ult iaccess linkInc. s, and ATM. Th e label- f or w ard in g com pon en t is in dependent of t he n et w or k lay er pr ot ocol. Use of con t rol com p onent ( s) specific t o a p art icular n et wor k lay er pr ot ocol enables t he usePub of lish label sw itPress ching w it h diff er ent net w ork lay er pr ot ocols. er: Cisco Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Label Pages: Switching 11 28 with ATM Becau se t he MPLS f orw ar din g p arad igm is b ased on lab el sw ap ping, as is ATM for w ard ing, MPLS t echnology can be ap plied t o ATM sw it ches by im plem en t ing t he cont rol com p onent . Th e label inf orm at ion needed f or MPLS sw it ch ing is car r ied in t he VPI and VCI f ield of ever y ATM cell. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

NO ConTE cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . The com binat ion of ATM, MPLS, an d I P t ech nology in t he ATM sw it ch es is usually called INew P+ ATM. chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age AutIhP+ ored bynet Cisco Sy stt he ems, w orsw ldw ide leader net w or kinglabel f or tset he up I n tm erech n et anism . I n most ATM w or ks, ATM it ches supp orint add it ional s ( for exam ple, ATM Foru m signaling) , and t he VPI field is u sed t o allocat e p art s of available label I n t ern et g iou Tech nologies Hand book ,ism Four h Edmitost ion ,net is wa or com ence t hat ed t o space t owtor hek vinar s label set up m echan s. tFor ks,pr a ehensive sin gle VPIrefer v alue allocat w oriskin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing tenables he MPLSnet LDP adequat e. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing st ryent . Lear how on t o incor por at netplifies w or kinint g egr t echn ologofies in t oswa itLAN/ ent . Iindu m plem ing nMPLS an ATM sweitint chersim at ion ATM chesWAN and renv outireronm s. An Com plet h new u pdatapp ed ear chapt er as on y , st or age, opt ical -net w or kr in g,er. scalabilit ATM sw itechw it cap able an of dMPLS s as r outsecur er t oitan adjacent packet b ased out This y, and t h is bookaltisern a at com an over d u p-lay t o-m d at e r ef er ence t o es t het he t opnics are essen t ial t o all pr ov speed, ides a scalable iveplet t o et he odel and r em ov eedt hat for ATM ad dr essing, or kin g p signaling rof essionals, r egar dless ofseexdest pertinise. rnet outwing , and schemes. Becau at ion- based f or w ard in g is t opology - dr iv en r at her t han t r af fic- dr iven, apply ing t his ap pr oach t o ATM sw it ches does not inv olve h igh call- set up Reader s w ill obtitain a g reaton er tun st an LAN and WAN n et w or k ing, p ar t icu lar ly t h e r at es, nor does depend he der long ev itding y of of f lows. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a r oad ent r ang of int egr st emsw s and in clud ing ion s, quest ions I mbplem inge MPLS on al ansyATM it ch serv doesices, not pr eclud e t det he ailed capabdescr ilit y tipt o sup porrev t aiew t r adit ional tATM o en con su ret r ol conplane cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ( su ch as PNNI ) on t h e same sw it ch. Th e t w o com pon en t s, MPLS and t he ATM Cov is e, also ext end ed n ot only n et/wor ingace concep t s,her butr esour also tces o old er t, itlegacy conterag r ol pelan operat e independ en t lyt ownew it h VPI VCIk sp an d ot par ioned so t hat syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in w hich t he com pon en t s do not int er act . pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Hierarchical Routing Essen t ial t o MPLS is t he n ot ion of b in ding bet w een a label and net w or k layer r out es. MPLS supp ort s a w ide r an ge of for w ar ding gr an ularit ies t o pr ovid e good scaling char act er ist ics w hile also accom m odat in g d iver se rou t ing fu nct ionalit y. At on e ex t r eme, a label can be associat ed •( bou nd) t o all Table rou of t esContent annous nced int o an I P net w or k fr om an edg e r out er t hr oug h BGP. This MPLS •fu nct ionalit y Ican ndexbe used ver y successf ully t o build high ly scalable I P n et wor k s, as exp lain ed in It his nt e rn et w ion. or k ing Te chnologie s H a ndbook , Four th Edit ion sect By Cisco Systems, Inc.

The I P rou t ing ar ch it ect ur e m od els a net w ork as a collect ion of r out ing dom ains. Wit h in a dom ain, rou t ing is pr ov id ed v ia int er ior r out ing ( such as OSPF) , an d r out in g acr oss dom ains is Pub lish er: Cisco Press pr ov ided v ia ex t erior r out in g ( su ch as BGP) . How ev er , all r out er s w it hin dom ains t h at car ry Pub Dat e: Sep tem ber 1 1, 2 003 t r ansit t r af fic ( such as dom ains for m ed by I SPs) mu st m aint ain infor m at ion pr ovid ed by ex t erior 58st 705 -1 er 19 -2 r out ingI SBN: , not1-ju int ior r out ing. Pages: 11 28

MPLS decouples int er ior and ext er ior r out ing so t h at on ly LSRs at t h e bor der of a d om ain ar e r eq uir ed t o m ain t ain r ou t ing in for m at ion pr ovid ed by ex t erior r ou t ing. All ot her sw it ch es w it h in t he dom ain m aint ain r out ing inf or mat ion p rov ided by t h e dom ain's int erior r ou t ing, w h ich usually is sm aller t h an t he ex t er ior r out in g in for m at ion. This, in t ur n, redu ces t he r out ing load on non dered swedit it chion es an sh ort ens rou t ing er gence t iming e. r ef erence p rov ides cover age of The bor u pdat of dt he b est - selling all-conv in- one net w ork essent ial an d cu t t ing- edg e t ech nologies. To su ppor t t his fu nct ionalit y , edge LSRs do not assign labels t o indiv idual BGP r out es, bu t r euse t he lab els assigned t o BGP nex t h ops f or all BGP dest inat ions t h at can be r eached t h r ough t hem , as show in Figur 32 -s8.of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Conn cise ov erev iew nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Figu r e 3 2 -8 . M PLS For w a r di ng Acr oss a BGP- Ba se d I P Ba ck bon e Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw[ View ide leader net w or king f or t he I n t er n et . full size in im age] I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. This f igur e show s a small I SP net w ork t hat has a few Point - of- Pr esence ( POP) r out er s connect ed t o a net w or k core com posed of t hr ee LSRs. Th e net w or k is also con nect ed t o a p eer in g point ( MAE- East in t he ex am ple) t h rou gh w hich it receiv es t he BGP r out e for n et w or k 1 92. 16 8. 3. 0/ 2 4. The I P packet for w ar ding fr om a POP rou t er t ow ard t h e ext er nal d est inat ion w it hin

19 2. 168 . 3. 0/ 24 ( or an y ot her d est inat ion adv er t ised via BGP f r om MAE- East ) is p er for m ed as follow s: St e p 1 . A POP r out er r eceiv es an I P dat agr am f or a dest in at ion w it hin I P n et w or k 19 2. 168 . 3. 0/ 24 .

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St e p 2 . The POP r out er p er f orm s Layer 3 look up, in ser t s an MPLS label header in fr on t of t he I P dat ag ram , an d for w ard s t he lab eled packet t ow ard t h e nex t - hop r out er . The label in Table of Content s t he MPLS lab el header is t he lab el assign ed t o t he BGP nex t h op, n ot t o t he ex t ern al I P I ndex net w or k.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By CiscoSt Systems, Inc. Cor e- 1 e p 3 . The

LSR f orw ar ds t he labeled p ack et t ow ar d t he d est inat ion ind icat ed in t he MPLS lab el st ack —t h e BGP n ex t hop.

Pub lish er: Cisco Press

e e: p Sep 4 . tem Thebersam pr ocess PubSt Dat 1 1, e 2 003

is repeat ed at t h e Cor e- 3 LSR.

I SBN: 1- 58 705 -1 19 -2

St e p 5 . The egr ess edge LSR ( MAE- East ) r em ov es t he MPLS label h ead er , p er f orm s Layer Pages: 11 28 3 looku p, an d f or war d s t he I P dat agr am t owar d t he ex t ern al dest inat ion.

Thr oug hout t his p r ocess, t he cor e LSRs never p er f orm a Lay er 3 looku p f or an ext er nal I P add ress. Thus, it ' s not necessar y t o r un BGP on t he cor e LSRs, redu cin g t h eir mem or y ut ilizat ion The uCPU and pdatload ed edit w hile ion incr of teasing he b estt-hselling e cor e alln etinworone k 's net st ab wilit orky ing . r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

MPLS-Based Virtual Private Networks On e of t he m ost p opular MPLS ap plicat ion s t oday is t he im plement at ion of v ir t ual p riv at e net w or ks ( VPNs) w it h t he help of MPLS t ech nology . To su ppor t MPLS- based VPNs, Cisco I OS w as m odified t o sup por t a larg e nu mb er of in dependent I P r out in g t ables wit h in a sin gle r out er —a •global I P r outTable ing tof abContent le ands a n um ber of Virt ual Rou t ing and Forw ar din g ( VRF) t ables. As show n •in Figur e 32 - 9, I ndex each VRF has it s own set of r out in g p rot ocols, oper at ing as an independ en t e rn or k ing chnologie H a ndbook , Four th tEdit rI nt out eretfwrom anTe IP rou t ings per sp ect iv e ( bu notionf rom a net w or k m anagem ent perspect ive, w h er e tBy heCisco wh ole r out erInc. is st ill m anaged as one d ev ice) . The t ot al independ en ce of t h e VRF t ab les allow s Systems, dif fer en t VPN net w ork s t o use ov er lapp in g I P addr ess sp ace. For ex am ple, VPN- A and VPN- B could bot h use net w or k 10 .0 . 0. 0/ 8. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 3 2 -9 . VRF Ar chi t ect u r e

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. The p otsent ialobt f orain ov er lapp ad dr spding ace bofetLAN weenand t heWAN VPN ncu s prpevent t he Reader w ill ag reatinerg un deress st an etst wom or ker ing, ar t icuslar ly sim t h e ple MPLS w ar par ad ig m hier I P rou t ing o bnology e used inf in or t h mat e MPLS VPN har dw for ar e, prding ot ocols, and serused v icesininv olvaredch. ical Fu ndam ent al ttech ion is pr ov ided on ar it ectruang re. eA of m ore com for sw and ar ding prices, ocessin usin a label st ack is needed seeiew Figur e 32ions a bchr oad int egr al plex sy st em serv clud ging det ailed descr ipt ion s, ( rev quest 10 . Th st ack is com osed t w or etlabels: t o )en su e relabel con cept comp r ehpen sion of and en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich The t op lab el at ( mar k ed Iand L or gu I GP label in ig ur e) , point in g per t owar d ance t he egwress LSR, is pr of essionals oper e. Tools id elines f ort he optf im izing syst em for m ill incr ease assig ned t hr ough LD P. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The b ot t om label ( mar k ed VL or VPN label in t he f ig ur e) , point in g t owar d a VPN dest inat ion, is assign ed by t he egr ess LSR and is pr opagat ed dir ect ly t o ot her edg e LSRs t hr ou gh mu lt ipr ot ocol BGP.

Figu r e 3 2 -1 0 . M PLS VPN For w ar d ing [ View full size im age]

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Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

A p ack et sent fr om Sit e A1 t o Sit e A2 is for w ard ed t h rou gh t he MPLS VPN back bone in t he The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of follow ing st eps: essent ial an d cu t t ing- edg e t ech nologies. St e p 1 . The I P dat agr am is sent fr om Sit e A1 t o t he in gr ess r out er . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom St eice p 2t .o Iex ngr ess. per for m s an I P looku p an d pr ep en ds an MPLS header consist in g of t w o nov pert labels—a label assig ned via LDP ( t he I GP label [ I L] ) , id en t ify ing t he p at h t ow ard t h e egr ess r out an d a VPN label ( VL) assigned by t h like e egrVoI essP rand out er . New chapt erer s ,include cov erag e of im por t ant t opics EAP St eerag p 3 .eThe p en ult im at e tcore t er ( tlik hee Core rountet erwor in kFigur e 32 st - 10) in t h e ser v ice Cov of cut t ing edge echn rou ologies opt ical ing and or age pr ov ider net w or k r em ov es t he I GP lab el, leav ing only t h e VPN label in t he MPLS h ead er . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . St e p 4 . The egr ess r out er per for m s label look up on t he VPN lab el, r em oves t h e MPLS I n t ern header et w or k in g Tech nologies Hand Fourt ow t h ar Eddit ion a com pr ehensive refer ence t hat , and f orw ar ds t he I P dbook at agr, am Sit e, is A2. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

MPLS Quality of Service An imp ort ant MPLS cap abilit y is QoS sup por t . Tw o mechanism s pr ov ide a ran ge of QoS t o pack et s passin g t hr ough a rou t er or t ag swit ch: • •

Table of Content s

Classif icat ion of pack et s int o diff er ent classes I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Hand lin g of p ack et s v ia app rop r iat e QoS char act erist ics ( such as band w id t h and loss)

By Cisco Systems, Inc.

MPLS pr ov ides an easy w ay t o m ark packet s as b elon ging t o a par t icular class aft er t h ey h ave Pubclassif lish er: Cisco been ied t Press h e fir st t im e. I nit ial classificat ion uses in for m at ion car r ied in t he n et w or k lay er or highPub er -Dat laye:erSep header tem ber s. 1 1,The 2 003pack et m ar king can be d one in t w o w ay s: I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

I n ATM env iron m en t s, a label cor r espon ding t o t he r esu lt ant class is app lied t o t he pack et . Lab eled packet s can be h andled ef ficien t ly by LSRs in t heir pat h w it hou t n eeding t o be r eclassif ied . I n all ot her env iron ment s, t he p ack et 's p r ecedence is st ored in 3 b it s in t he MPLS label The uheader pdat ed. edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The act u al pack et sch ed uling and qu eu in g are lar gely or t hog onal. The key poin t her e is t h at MPLS let s y ou u se sim ple logic t o fin d t he st at e t h at ident if ies how t h e pack et should be cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom sch edCon uled. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

MPLS Traffic Engineering On e of t he f und am en t al pr oper t ies of dest in at ion- based r ou t ing is t hat t he on ly in for m at ion fr om a p acket t hat is used t o for w ar d t h e pack et is t he dest in at ion ad dr ess. Alt hou gh t his p rop er t y enables hig hly scalable r ou t in g, it also limit s t he capabilit y t o inf lu en ce t he act ual pat hs t aken by •pack et s. ThisTable s limitof s Content t he capabilit y t o evenly d ist r ibut e t r aff ic amon g mu lt ip le lin ks, t aking t h e •load off hig hly I ndex ut ilized link s an d shif t ing it t ow ar d less- ut ilized link s. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

For I SPs t hat supp By Cisco Systems, Inc.ort dif ferent classes of ser v ice, d est inat ion - based r out in g also lim it s t heir capabilit y t o segr egat e diff er ent classes wit h r esp ect t o t h e link s used b y t hese classes. Som e I SPs t oday use Fr am e Relay or ATM t o over com e t h e limit at ion s im posed by dest in at ion - based Pub lish er: Cisco Press r out ing . Becau se of t he f lex ible gr anu lar it y of labels, MPLS can over com e t h ese lim it at ions Pub Dat e: Sep tem ber 1 1, 2 003 w it hout using eit her Fram e Relay or ATM. To p r ovide for w ard ing along t he p at hs t h at ar e 1- 58t705 dif fer enI SBN: t f rom he -1 p 19 at -2 hs d et er m in ed b y dest in at ion- based rou t ing, t he cont r ol com pon en t of 28 allat ion of label b in ding s in LSRs t h at d o not corr espond t o t he d est inat ion MPLS Pages: allow s11inst based rou t ing pat hs. Tr aff ic en gineerin g allow s a net w ork ad m in ist r at or t o m ak e t he p at h det er m inist ic and by pass t he nor mal r out ed h op- b y- h op p at hs. An adm inist r at or m ay elect t o exp licit ly def in e t he pat h bet or kion endp o en sur e QoS or one maynet hav e t he f ollowp rov a specified p at h tof o Thewueen pdatnet edwedit of oint t he sb test - selling all- inw ork ingt raf r effic erence ides cover age ressent ed uceial t r aff ic loading across cer t ain link s. I n ot her w or ds, t he n et wor k ad min ist r at or can r ed uce an d cu t t ing- edg e t ech nologies. congest ion by for cing t he fr am e t o t r av el ar ound t h e over loaded segm ent s. Tr aff ic engineerin g, t hen, let s an ad min ist r at or d ef ine a policy for f or war d in g f r am es r at h er t han dependin g on dy nam ic rcise out in ocols. Con ovgerpvrot iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Tr aff ic en gineerin g is sim ilar t o sour ce r out ing in t hat an ex plicit pat h is d ef ined f or t h e fr am e t o t r av el. Howchapt ev er er , usnlike sourcov ce erag r out e ing t hepor hopb yh op definit ionP is notEAP car r ied w it h ever y fr am e. New include of, im t ant t opics like VoI and Rat h er , t he hop s ar e configu r ed in t he LSRs ahead of t im e along w it h t h e app rop riat e lab el v alues. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age A n umAut berh ored of exist by ing Cisco pr ot Syocols st ems, w ere w ormod ldw ide if iedleader t o supp in ort nettwhe or need king sf or of t MPLS he I n t ter r aff n etic. en gineer ing : I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Ex t net ensions t ogOSPF and I S- I S ave b een o allow lin por k- star atye int pr er ot net ocols t o ing enables w or kin p r ofessionals t ohun derst anddefin an dedimt plem en tt hese cont em w ork pr opag at e t he lin k ut ilizat ion in for m at ion acr oss t he n et wor k . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Conestwr it aint - based inged h as been plem en tited Cisco OS ical t o allow t he eadscalabilit en d rou y, t er s Com plet h new an dr out u pdat chapt er simon secur y , in st or age,I opt net w or k inh g, t o find opt im al p at hs acr oss t he n et wor k b ased on operat orest ablished cr it eria. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Resour ce Reser vat ion Pr ot ocol ( RSVP) has b een ext end ed t o supp ort t he est ablishm ent an d m saint plicit r out LSPs. Reader w illenance obt ainofa ex g reat erlyun dered st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary Mu lt ip rot ocol Label Sw it ching ( MPLS) is a t ech nology t h at com bines t h e benefit s of conn ect ionor ien t ed Layer 2 for w ar ding w it h t he b en ef it s of connect ionless Layer 3 I nt er net Pr ot ocol ( I P) . I n MPLS- en abled n et w or k s, all net w or k devices become I P- aw ar e. They r un I P r out in g p r ot ocols on •t he con t r ol plane Table w ofhContent ile perfs or ming t h e act ual p ack et f or war d in g based on labels allocat ed t o I P •pr efix es w it h I ndex a var iet y of label dist r ibut ion pr ot ocols. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

The ab ilit y t o p er for m p acket f or w ard ing in t h e core of an I P net w ork w it h out perf or ming an I P By Cisco Systems, Inc. look up at ev er y h op enab les a v ariet y of new solut ion s: Pub lish er: Cisco Press Pub Dat Seprtem 1 1,w2it003 I nt ere:net outber in g h gr eat ly

r ed uced I P r ou t in g t ables on t he cor e r out ers

I SBN: 1- 58 705 -1 19 -2

MPLSbased t r aff ic engineer in g ( MPLS TE) Pages: 11 28 MPLS- based Vir t ual Pr iv at e Net w ork s ( MPLS VPNs)

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: • •

I n dow nst r eam - on - deman d dist ribu t ion, h ow does t h e upst r eam LSR k now it needs a Table of Content s label? I ndex

I nt e rn k ingdTe chnologie s H a ndbook , Four 2 et : w or How oes FI B d iffer f r om LFI B?th Edit ion By Cisco Systems, Inc.

3:

What ar e t he t w o LD P m odes?

Pub lish er: Cisco Press

4:

I t is h ighly r ecom m ended t hat neighb or LSRs operat e in t h e same LDP mod e. What m ight hap pen if an up st r eam LSR op er at es in dow nst r eam unsolicit ed dist r ib ut ion I SBN: 1- 58 an 705d-1t19 m ode he-2 dow n st r eam LSR r un s in d ow nst r eam - on- d em an d m od e?

Pub Dat e: Sep tem ber 1 1, 2 003

Pages: 11 28

5:

I f a v endor 's rou t er already uses h igh- speed sw it ching and caching t ech niqu es t o for w ar d fr am es, p er f orm an ce m igh t n ot b e a v alid m ot iv at ion for u sing MPLS. I s t her e any ot her r eason t hat m ig ht m er it d ep loym ent of MPLS in such a n et w or k ?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • McD ysan, Dav id Ph .D ., QoS and Tr aff ic Man agem ent in I P and ATM Net wor k s , McGr aw - Hill Pr ofession al Publishing : New Yor k , 20 00. •

Table of Content s

•

I ndex

•I nt Pep , I van , Jim Gu d , and Jeff Apcar e rn etelnj w orak k ing Te chnologie s Hichar a ndbook , Four th Edit ion , Adv anced M PLS an d VPN Ar ch it ect ur es, Volu m e I I , Cisco Pr ess, 2 003 . By Cisco Systems, Inc.

• Pep Pub elnj lish er: akCisco I van Press , and Jim Guich ar d, MPLS and VPN Ar chit ect u res, CCI P Edit ion , Cisco Pr ess, 20 02. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 28 • w w w Pages: .cisco.11 com / w arp / pu blic/ 7 32/ Tech/ m pls/

• w w w .iet f .or g/ ht m l.char t er s/ mp ls- char t er .h t m l The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of • w w w .iet f .or g/ rf c/ rf c2702 . t xt essent ial an d cu t t ing- edg e t ech nologies. • w w w .m p lsr c.com / Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 33. Data-Link Switching Obj e ct i ve s • •

Table of Content s

Descr ibe t he need for DLSw . I ndex

I nt e rn Know et w or k ing chnologie s H aof ndbook th sour Edit ion t heTe ad van t ages DLSw, Four over ce- rou t e

br idg in g.

By Cisco Systems, Inc.

Specify t h e t r anspor t p rot ocol bet w een DLSw sw it ches. Pub lish er: Cisco Press

Under st and t he b asic st r uct ur e of D LSw .

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2p rocesses by nam e and fu nct ion. Recognize D LSw Pages: 11 28

Under st and t he cir cu it est ablish ment pr ocess.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background Dat a- link sw it chin g ( DLSw) p r ovides a m ean s of t r anspor t ing I BM Sy st em s Net w or k Ar ch it ect ur e ( SNA) an d net w ork basic in put / out pu t sy st em ( Net BI OS) t r aff ic over an I P n et w or k . I t ser ves as an alt er n at iv e t o sour ce- r out e br id ging ( SRB) , a pr ot ocol for t r anspor t ing SNA and Net BI OS •t r aff ic in Token Table of Content s ment s t hat w as w id ely d ep loyed befor e t h e int r oduct ion of DLSw . I n Ring env ir on •gener al, DLSw I ndex addr esses som e of t he shor t com ings of SRB f or cer t ain comm un icat ion Ir nt rn et w or k ing Te chnologie Four th Edit eqeuir em ent s—par t icularslyH ainndbook W AN, im plem ention at ion s. This chapt er cont rast s D LSw w it h SRB, sum m arizes un der By Cisco Systems, Inc.ly ing pr ot ocols, and pr ov ides a sy nopsis of nor m al pr ot ocol op er at ions. DLSw init ially em er ged as a pr op riet ar y I BM solut ion in 1992 . I t w as fir st subm it t ed t o t h e I ETF Pub lish er: Cisco Press as RFC 14 34 in 1 993 . DLSw is now docum en t ed in det ail b y I ETF RFC 179 5, w hich w as Pub Dat e: Sep tem ber 1 1, 2 003 subm it t ed in Ap ril 199 5. DLSw w as j oin t ly dev eloped by t h e Adv anced Peer - t o- Peer Net w or kin g 1- 58 705 ( APPN)I SBN: I m plem en -1 t or19s-2Wor kshop ( AI W) and t he D at a- Link Sw it chin g Relat ed I n t erest Grou p ( DLSwPages: RI G)11 . 28 RFC 179 5 d escr ibes t hr ee pr imar y f un ct ion s of DLSw : The Sw it ch- t o- Swit ch Pr ot ocol ( SSP) is t he pr ot ocol m aint ain ed bet w een t w o DLSw nodes The uor pdat ederedit r out s. ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The t er m inat ion of SNA dat a- lin k con t r ol ( DLC) con nect ion s helps t o redu ce t he lik elihood of link lay er t imeout s acr oss WANs. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice to m exapp perting . of DLC connect ions t o a D LSw cir cu it . The local chapt s ions include cov erag einof det im ail porin t ant Each New of t hese fuer nct is discussed t hist opics chaptlike er . VoI P and EAP Cov of cut t ing edge t echn e opt worpr k ing and enh st orancem age ent s t o RFC I n 199 7, erag t h e IeETF r eleased DLSw v erologies sion 2 ( lik RFC 21 ical 66) nwet hich ovides 17 95 docum ent . Th e addit ion al feat ur es include t hese: Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ernI et in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Pw mor ultkicast enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mastrer t he ses t er m con cep s, t echnsologies, an d devices used in t oday ' s net w ork ing UDP u nicast espon t os,DLSw brtoadcast indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new d ud pdat edd chapt En hanced p eeran - onem an r out iner g s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or Exkin pedit g ped rof essionals, TCP con nect r egar ion sdless of ex pert ise. Each ofst w Reader hese ill obt feat ain ur aesg enables reat er unDLSw der st an as ding a scalable of LANt echnolog and WANy nover et w orWANs. k ing, pI ar n DLSw t icu lar ly Vert hsion e 1, thar r ansact dw ar ions e, pr occur ot ocols, w itand h TCP. ser vAs ices a rinv esult olv, ed man . Fuy ndam oper at ent ions al tin echa nology D LSw env inf or ir mat onmion en tisconsum pr ov ided ed on a b r oad circuit s bet r ang w een e of peer int egr s. al For syexam st em sp le, anda serv m ultices, icastinr eq clud uired ing det m ult ailed iple descr TCP connect ipt ion s, ions rev iew f rom quest t he ions t o ence sour su tre o each con cept p eercomp . WitrhehDLSw en sionVersion and r et2, enm t ion, ult icast and is adddit istional r ibu t ed r esou u sing r cesu nr f oreliable fu rt hert r ansp st udyort . Cov erag follow inge tis r adit also ional ext end mu lt edicast n ot met onlyh ods. t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Not t h at RFCoper 21 66 does notand super 1795 it adds ion per alit for y and m ainwtill ains ack w ar d pr ofeessionals at e. Tools gucede id elines f or, bu optt im izing fun systctem m ance incrb ease com pat pr odu ct ibilit iv it y y.an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Cisco supp ort s a t h ird v er sion of DLSw called D LSw + . DLSw+ pr edat es DLSw Ver sion 2 an d pr ov ides ev en fur t h er en hancement s t o b asic D LSw . DLSw + is fu lly com pliant w it h RFC 1 795 . The enh ancement s may be used wh en b ot h peer s ar e Cisco dev ices r un ning DLSw + . This chap t er focuses on t he b asic f unct ion of DLSw as def in ed in RFC 1795 .

Figur e 33 - 1 illust r at es a g en er alized D LSw env ir onm en t .

Figu r e 3 3 -1 . A D LSw Cir cui t Fa cil it a t e s SNA Con ne ct iv it y ov er an I P W AN •

Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DLSw Contrasted with Source-Route Bridging The p r in cip al dif ference b et w een SRB an d D LSw inv olv es su ppor t of local t er m inat ion. SNA and Net BI OS t r aff ic r ely on link lay er ackn owledg ment s and k eepaliv e m essages t o ensur e t he int egr it y of connect ions an d t he deliver y of dat a. For con nect ion - or ient ed dat a, t he local DLSw •nod e or r out er Table t erof m Content in at es sdat a- link cont rol. Th er efor e, link lay er ack now ledgm ent s and •k eepaliv e m essages I ndex do not hav e t o t rav erse a WAN. By cont r ast , D LC for SRB is han dled on an Iendnt e rnt et ord k ing Te chnologie H a ndbook Four th Edit pot ion ent ial f or DLC t im eout s over WAN con nect ion s. o-wen b asis, w hich sr esult s in ,incr eased By Cisco Systems, Inc.

Alt hou gh SRB h as been a v iab le solu t ion f or m any env ir onm en t s, sev eral issues lim it it s usefu ln ess f or t r anspor t of SNA and Net BI OS in WAN im plem en t at ions. Ch ief am ong t hem ar e Pub lish er: Cisco Press t he follow in g con st r aint s: Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

SRB Pages:hop11 28coun t lim it at ion of sev en hop s Br oadcast t r aff ic han dling ( fr om SRB exp lorer f ram es or Net BI OS n am e quer ies) Unnecessar y t r aff ic for w ard ing ( ackn owledg ment s and keepaliv es) The uLack pdat ed ofr ol t heand b est - selling of fedit lowion cont p rior it izatallion in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Figur e 33 - 2 illust r at es t he basic en d- t o- end nat u r e of an SRB connect ion over a WAN link . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Figu r e 3 3 -2 . SRB Pr ov id es a n End- t o- End Con ne ct ion ove r a n I P W AN New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu tcterivmit inat y anion d im ov e connect eff iciency, t heprr eader mor in adv t elligent , cost Local ofprDLC ionshelp b y ing DLSw ovid esma ake nu mb ereof ant ages ov- eff er icient SRB- based decisions for t h eir net w ork s. env iron ment s. DLSw local t er m inat ion elim inat es t he requ ir em en t f or link lay er ackn ow ledg m en t s and k eepaliv e m essages t o flow acr oss a WAN. I n add it ion , local t erm inat ion r ed uces t he lik elihood of link lay er t imeout s acr oss WANs. Sim ilar ly , DLSw ensur es t hat t he br oadcast of sear ch f ram es is cont r olled by t he DLSw w hen t he locat ion of a t ar get sy st em is discover ed . Figur e 33 - 3 illust r at es t he flow of inf or mat ion and t h e use of local ackn owledg ment in a DLSw env iron ment .

Figu r e 3 3 -3 . D LSw U se s Loca l Ack n ow l ed gm en t t o Cont r ol D at a Fl ow

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DLSw SNA Support On e of t he ad van t ages inher ent in DLSw is t hat it su pplies br oader dev ice an d media su ppor t t han p rev iously available w it h SRB. D LSw accom mod at es a nu m ber of t y pical SNA env iron ment s and pr ov ides for I EEE 802 . 2- com pliant LAN sup por t , w hich in clu des suppor t for SNA ph ysical •un it ( PU) 2 , PU Table of Content 2. 1, and PUs 4 sy st ems and Net BI OS- b ased syst em s. •

I ndex

IDLSw nt e rn etpr w ov or kides ing Tefor chnologie H a ndbook , Four th Edit ionr ol ( SD LC) supp ort , cov er in g PU 2 ( p r im ar y or Sy nchrs on ous Dat a Link Cont second ar y) and PU 2. 1 syst em s. Wit h SD LCat t ach ed sy st em s, each SDLC PU is pr esent ed t o t h e By Cisco Systems, Inc. DLSw Sw it ch - t o- Sw it ch Pr ot ocol ( SSP) as a uniqu e Media Access Cont r ol ( MAC) / ser v ice access point ( SAP) addr ess pair . Wit h Token Ring –at t ached sy st ems, a DLSw node appear s as a sou rcePub lish er: Cisco Press r out e b rid ge. Rem ot e Tok en Rin g sy st em s accessed v ia a DLSw node ar e seen as at t ach ed t o an Pub Dat e: Sep tem ber 1 1, 2 003 adj acen t r ing. This app arent adj acen t r ing is k now n as a v ir t ual r ing creat ed w it hin each DLSw I SBN:e1-33 58 705 -1 19 -2r at es v ariou s I BM nod es con nect ed t o a TCP/ I P WAN t h rou gh DLSw nod e. Figur - 4 illust Pages: 11 28 in t his case, ar e rou t ers. dev ices, w hich,

Figu r e 3 3 -4 . SNA Nod es Conn ect Th r ough TCP/ I P W AN vi a DLSw The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DLSw Switch-to-Switch Protocol Sw it ch - t o- Sw it ch Pr ot ocol ( SSP) is a pr ot ocol u sed bet w een DLSw nodes ( r ou t er s) t o est ab lish connect ions, locat e r esour ces, for w ard d at a, and han dle flow con t r ol and err or r ecover y. This is t r uly t h e essence of DLSw . I n gener al, SSP d oes not p r ovide for f ull r out in g b et w een nodes •because t his Table ofer Content s dled b y comm on r out ing pr ot ocols such as RI P, OSPF, or is g en ally han •I GRP/ EI GRP.I ndex I nst ead, SSP swit ches p ack et s at t he SNA dat a link lay er . I t also encapsulat es Ipack nt e rnet etsw in or kTCP/ ing TeI P chnologie s H a ndbook , Four Edit ion for t r anspor t ov er I P-th based n et w or k s and uses TCP as a m eans of r eliab le t r anspor t bet w een By Cisco Systems, Inc. DLSw nodes. Figur e 33 - 5 illust r at es w her e SSP f alls in t h e over all SNA ar ch it ect u re, an d show s it s relat ionship t o t he OSI ref er ence m odel. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Figu r e 3 3 -5 . SSP M aps t o t h e Da t a Li nk Com pon en t s of SNA a nd t h e Pages: 11 28 O SI Ref e r en ce M ode l

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DLSw Operation DLSw inv olves sever al oper at ional st ag es. Tw o DLSw p ar t ners est ablish t w o TCP connect ions w it h each ot her . TCP con nect ion s pr ov ide t h e foun dat ion for t he DLSw com mu nicat ion. Because TCP pr ov id es for r eliab le and guar an t eed deliver y of I P t r aff ic, it ensur es t he d eliv er y an d •int egr it y of t hTable of ic Content e t r aff t hat sis being en cap su lat ed in t he I P pr ot ocol, w hich , in t his case, is SNA •and Net BI OSI ndex t r af fic. Aft er a connect ion is est ablished, t h e DLSw par t ner s exchan ge a list of Isupp nt e rnort et wed or kcapabilit ing Te chnologie s H ais ndbook , Four th ionwh en t h e DLSw par t ner s ar e m anuf act ur ed b y ies. This par t icular ly Edit vit al difCisco fer enSystems, t v endorInc. s. Next , t he DLSw par t n er s est ablish cir cu it s bet w een SNA or Net BI OS en d By syst em s, and infor m at ion fr am es can f low ov er t he circuit . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

DLSw Processes I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The ov er all DLSw operat ion al pr ocess can be b r oken int o t hr ee b asic com pon en t s: capabilit ies exchan ge, circuit est ab lishm ent , and flow cont rol. I n t he con t ex t of DLSw , capabilit ies ex change inv olves t h e t r ading of inf orm at ion abou t capab ilit ies associat ed w it h a DLSw session . This exchan ge of inf or mat ion is negot iat ed w hen t he session is init iat ed an d dur ing t he cou rse of session op er at ion s. Cir cu it est ab lish m ent in DLSw occu r s bet w een end sy st ems. I t includes The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of locat ing t he t ar get en d sy st em and set t in g u p dat a- link cont r ol con nect ion s bet w een each end essent ial an d cu t t ing- edg e t ech nologies. syst em an d it s local r out er . D LSw flow cont rol enab les t he est ablish ment of ind ep en dent , un id irect ional f low cont r ol b et w een p ar t ners. Each p rocess in d iscussed in t he sect ion s t hat followCon . cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP DLSw Capabilities Exchange Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age DLSw capabilit ies ex chang e is based on a sw it ch- t o- sw it ch con t r ol m essage t h at d escr ib es t he capabilit of t by he Cisco sending d at a- linwkorsw it ch . Aleader capabin ilitnet ies wexchan Auties h ored Sy st ems, ldw ide or kingge f orcont t her ol I n tm eressag n et . e is sen t af t er t he sw it ch- t o- sw it ch con nect ion is est ablish ed or d ur ing r un t ime, if cert ain oper at ional par amet etweror s kt hinat m ustnologies be com m unicat ed , t Four o t het hpar havpr e ehensive chan ged. refer Du r in g t he I n t ern g Tech Hand book Edtitner ionsw , isit achcom ence t hat capabilit ies ex chang e, a n um ber of capabilit ies are id en t ified an d negot iat ed. Cap abilit enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net ies w ork ing exchan ged betMast w een t ner s cep inclu t h e follow ing:an d devices used in t oday ' s net w ork ing t echnologies. er DLSw t he t erpar m s, con t s,det echn ologies, indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, DLSw v er sion n um ber and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. I nit ial p acing w ind ow siz e ( r eceiv e w ind ow size) Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Net BI OS supp or t har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad e ppor of intt ed egrlin al ksySAPs st em (sLSAPs) and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Listr ang of su t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e ber is also ext end ed n otsup only new n et wor k ing concep t s, but also t o old er , legacy Num of TCP sessions port ot ed syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals e.sTools and gu id elines f or opt im izing syst em per for m ance w ill incr ease MAC addoper ressat list pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Net BIfor OSt hnam e list s s. decisions eir net w ork Search fr am es supp ort

DLSw Circuit Establishment

The p r ocess of cir cuit est ablishm ent bet w een a p air of en d sy st em s in DLSw inv olves locat ing t he t ar get end sy st em an d set t ing u p d at a- link cont r ol ( D LC) con nect ion s bet w een each end sy st em and it s local r out er . The sp ecifics of circuit est ab lishm ent diff er based on t r af fic t y pe. On e of t he p rim ar y fu nct ions of DLSw is t o pr ov id e a t r an sp ort m echan ism for SNA t r affic. SNA circuit est ab lishm ent inv olv es sev er al dist inct st ages an d is illust r at ed in Figur e 33 - 6. •

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Figu r e 3 3 -6 . D LSw Cir cui t Est a bl ishm e nt Fl ow

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat First , SNA devices on a LAN find ot h er SNA dev ices by send in g an ex plor er fr am e w it h t he MAC enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing add ress of t he t arg et SNA d ev ice. When a DLSw int er net w ork ing nod e r eceiv es an exp lor er t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing fr am e, t hat nod e sen ds a canur each f r am e t o each of it s D LSw p art ners. Th e fu nct ion of t h is indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . fr am e is t o quer y each of t h e DLSw par t ner s t o see w het her it can locat e t h e device in quest ion. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, I f one of t h e DLSw par t ner s can r each t h e specif ied MAC add ress, t he p art ner r ep lies w it h an and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all ican reach fr am e, w hich indicat es t hat a specific DLSw par t n er can pr ov ide a com m un icat ions net w or kin g p rof essionals, r egar dless of ex pert ise. pat h t o t he d ev ice in q uest ion . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Aft er t he canur each an d icanr each f r ames h ave b een exchan ged, t h e t w o D LSw p art n er s har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on est ablish a cir cuit t h at consist s of a D LC connect ion b et w een each rou t er and t he locally at t ached a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions SNA end sy st em ( f or a t ot al of t w o con nect ion s) and a TCP conn ect ion bet w een t he DLSw t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . par t n er s. The r esult ing cir cuit is uniqu ely id en t ified b y t he sou rce and d est inat ion circuit I Ds. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Each SNA DLSw circuit I D in clud es a MAC add ress, a link - ser v ice access point ( LSAP) , an d t he syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich DLC p ort I D. Cir cuit pr iorit y is negot iat ed at circuit set u p t im e. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv circuit it y an dest imab pr lishm ov e eff iciency, helpSNA ing tcir hecuit r eader m ake mor cost - eff icient Net BI OS ent par allels est ablishm ent ,ewinitthelligent a f ew ,dif ferences. Fir st , decisions for t h eir net w ork s. w it h Net BI OS cir cuit est ablishm ent , D LSw n odes send a nam e qu er y w it h a Net BI OS nam e ( not a canur each f r ame sp ecify ing a MAC ad dr ess) . Sim ilar ly , t he DLSw nodes est ablish in g a Net BI OS circuit sen d a nam e r ecog nized f ram e ( not an icanr each f ram e) .

DLSw Flow Control

DLSw flow con t r ol inv olves adap t iv e pacing b et ween DLSw rou t er s. Du r in g t he f low - cont rol negot iat ion , t w o ind ep en dent , unidir ect ion al flow - cont r ol m echanism s ar e est ab lished bet w een DLSw par t ner s. Adapt iv e p acing em ploy s a w ind ow in g m echanism t h at d yn amically adapt s t o bu ff er availabilit y . Window s can be in cr em en t ed , decrem ent ed, h alved, or reset t o zer o. This allow s t he D LSw n odes t o cont rol t he p ace of t raf fic f or war ded t hr oug h t he n et w or k t o en su r e int egr it y and d eliv er y of all d at a. •

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DLSw Flow-Control Indicators I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Gr ant ed un it s ( t he nu m ber of unit s t hat t he sender h as perm ission t o sen d) ar e incr ement ed w it h a f low - con t r ol indicat ion ( one of sever al possible ind icat or s) f r om t he r eceiv er . D LSw f low cont r ol Pub lish er: Cisco Press pr ov ides for t he f ollow ing ind icat or fun ct ion s: Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Re Pages: pe at 11— 28 I n cr em en t s gr ant ed un it s by t h e cur rent w indow size. I ncre m en t — I n cr eases t he w indow size by 1 and incr eases gr ant ed unit s by t h e new w indow size. D e cr em e nt — Decr ement s w indow size b y 1 and increm en t s gr an t ed un it s by t he new The uw pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of indow size. essent ial an d cu t t ing- edg e t ech nologies. Re set — Decr eases w ind ow size t o 0 and set s gr ant ed un it s t o 0 , w hich st op s all t r ansm ission in on e dir ect ion unt il an in cr em en t f low- con t rol indicat or is sent . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice Cut t o ex . r en t w ind ow size in h alf and in crem en t s gr ant ed un it s by t h e new H a lf— s pert t he cur w indow size. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Flow — Cont r ol in dicat ors and flow - cont r ol ack now led gm en t s can be pig gy backed on Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age inf orm at ion fr am es or sent as in dependent f low - cont r ol messag es. Reset in dicat ors are alw sent ind ep dent messag es. leader in net w or king f or t he I n t er n et . Aut hays ored by as Cisco Syen st ems, w or ldw ide I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g Examples Adaptive-Pacing p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu ry . Lear n how t opacing incor por ater e ia intinclude er net w or kin t echn olog LAN/ WANion, envout ir onm Ex amstples of adapt iv ecrit buf ferg av ailab ilit yies , t rin ant ospaort ut ilizat bouent nd. Com e gt w it newt ran pdat edy .chapt s onofsecur y , st or age, icalt onet or k in g,pacing scalabilit y, : qu euplet e len h,h and affdicu pr iorit Examerples how iteach can b e opt used infwluence follow and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Buf fe r av a ila bi li t y — I f m em ory buf fer s in a DLSw node are cr it ically low , t h e nod e can Reader s w ill ent obt ain reat un der an dingt hof LAN of and WAN n etbwuff or er k ing, p ar t icuylarincr ly teases, he decrem t he awgind owersize t o st r educe e flow t raf fic. As availabilit t he har dwnod ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided ons. e t hen can incr ease t he w indow size t o incr ease t r af fic f low bet w een t he DLSw par t ner a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su Tra renspor con cept t utcomp ili z atrieh on— en sion I f t hand e link r etbet en twion, eenand t w oad DLSw dit ional par rt ner esou s r ces eaches f or fu a rt high her lev st udy el of . Cov erag ut ilizat e is ion, also text he end w ind edown ot size only cant obe new redu n et ced wort ok ing low concep er t h e lev t s, el but of also link tut o ilizat old erion , legacy and t o syst em prs, event pr ovid pack in geta loss m or bet e r ealist w eenict he pictnodes. ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease bound euov e eleeff ngt h — Traf fic ing f or war by amDLSw nod pically ,iscost p laced in t o an pr oduOut ct iv it y an d qu im pr iciency, help t hedred eader ake mor e einttyelligent - eff icient out b for ound q ueue, hich decisions t h eir net wwork s. is a por t ion of mem or y dedicat ed t o t r aff ic being for w ar ded b y one dev ice t o anot h er . I f t h is queue r eaches a specified t hr eshold or p er hap s becomes f ull, t he nu mb er of gr ant ed unit s can be r edu ced unt il t he q ueue ut ilizat ion is r ed uced t o a sat isf act ory lev el. Tra ff ic pri ori t y— One of t h e un iq ue capab ilit ies of t he SSP is it s capabilit y t o pr iorit ize

specif ic t r aff ic. Th ese p rior it ies are id en t ified by t he Cir cu it Pr iorit y f ield in t he D LSw m essage f r ame. By pr ovidin g a v ary ing nu mb er of gr ant ed unit s t o specif ic DLSw cir cuit s, t he nodes can main t ain d iffer ent lev els of p rior it y t o each circuit .

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DLSw Message Formats Tw o m essag e header for m at s ar e ex ch anged bet w een DLSw nod es:

• •

Con t rol Table of Content s I ndex

at ion I nt e rn Ietnf worm or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

The con t rol m essage header is u sed for all m essages except in for m at ion fr am es ( I f r ames) an d independ en t f low cont r ol m essag es ( I FCMs) , wh ich ar e sen t in inf orm at ion header f orm at . Pub lish er: Cisco Press

Figur e Dat 33 e: - 7Sep illust at es Pub tem rber 1 1, t2he 003for m at of t h e DLSw Cont r ol an d I n for m at ion f ield s. These f ield s ar e discussed et705 ail-1in I SBN:in1-d58 19 t-2he subsequent descr ipt ion s. Pages: 11 28

Figu r e 3 3 -7 . D LSw Cont r ol an d I nf or m a t ion Fr am e s Ha ve Th ei r Fir st 1 6 By t e s in Com m on The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.[ View full size im age] Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich The f ollow in g f ield s ar e illu st r at ed in Figur e 33 - 7 ( field s in t he f ir st 16 by t es of all DLSw m essage pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease header s ar e t he sam e) : pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. V e rsion num be r— When set t o 0x 31 ( ASCI I 1) , ind icat es a decim al v alue of 4 9, w hich ident if ies t h is device as u t ilizin g D LSw v ersion 1. Th is w ill allow fut ur e int er operab ilit y bet w een DLSw nod es usin g diff er ent ver sion s of t he DLSw st an dar d. Cur rent ly , all d ev ices ut ilize DLSw v er sion 1, so t h is field w ill alw ay s hav e t h e decim al v alue of 4 9.

H e ade r le ng t h— When set t o 0x 48 f or cont r ol m essages, ind icat es a decim al v alue of 7 2 by t es. This v alue is set t o 0x 10 for in for m at ion and independ en t f low cont r ol m essages, indicat ing a decim al v alue of 1 6 b yt es. Me ssa ge le ngt h — Defines t he num ber of b yt es w it hin t h e dat a field f ollow ing t h e header . Re m ot e da t a- li nk cor re la t or— Work s in t and em w it h t h e r em ot e D LC por t I D t o for m a 64 - bit cir cuit I D t hat ident ifies t h e DLC circuit w it hin a single D LSw n ode. The cir cu it I D is • Table of Content s un iq ue in a sing le DLSw node an d is assigned locally . An end- t o- end cir cu it is ident if ied by • a p air ofI ndex cir cuit I D s t hat , along w it h t h e dat a- link I D s, uniqu ely id en t if ies a single end - t oI nt e rn end et w orcir k ing Te. chnologie s H a ndbook , Four Edit ion cuit Each DLSw nod e m ust thk eep a t able of t h ese circuit I D p airs: one f or t he local By Cisco end Systems, of t he Inc. cir cu it and t h e ot her f or t he rem ot e end of t he cir cu it . The rem ot e dat a- lin k corr elat or is set equal t o t he t ar get d at a- link cor relat or if t h e Fr am e Dir ect ion f ield is set t o 01 I t is Press equ al t o t he or igin dat a- link cor r elat or if t h e Fram e D ir ect ion f ield is set t o 0x 02. Pub0x lish er:. Cisco Pub Dat e: Sep tem ber 1 1, 2 003

Re m ot e D LC por t I D — Work s in t and em w it h t h e r em ot e d at a- link cor relat or t o for m a I SBN: 1- 58 705 -1 19 -2 64 - bit cir cuit I D t hat ident ifies t h e DLC circuit w it hin a single D LSw n ode. The cir cu it I D is Pages: un iq ue11in28a sing le DLSw node an d is assigned locally . The en d- t o- end circuit is ident ified by a p air of cir cuit I D s t hat , along w it h t h e dat a- link I D s, uniqu ely id en t if ies a single end - t oend cir cuit . Each DLSw dev ice mu st k eep a t ab le of t hese cir cuit I D pair s: on e for t he local end of t he cir cu it and t h e ot her f or t he rem ot e end of t he cir cu it . The rem ot e DLC p ort I D is set equal t o t h e t ar get D LC por t I D if t he Fr ame Direct ion field is set t o 0x 01 . I t is equ al t o he orig DLC I Db if t he Fr ameallD inirect ionnet f ield is ing set rt oef erence 0x 02. p rov ides cover age of The utpdat ed in edit ion por of tthe est - selling one w ork essent ial an d cu t t ing- edg e t ech nologies. Me ssa ge t yp e— I n dicat es a specif ic DLSw m essage t y pe. Th e valu e is sp ecif ied in t wo dif fer en t f ields ( off set 14 and 23 decim al) of t he cont r ol m essag e header . Only t he f ir st f ield Con is used cise wh ov en er vpiew arsing s of taechn r eceiv olog edies SSP essen m essage. t ial t o nThe et wor second k ing pr field ofession is ignals or ed at by all lev newels, f rom im novplem ice tent o ex atpert ion s. on recept ion, b ut it is r et ained f or back w ard com pat ibilit y w it h RFC 1 434 im plem ent at ion s and can be used in f ut ur e v ersions, if needed. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Flow - cont r ol by t e— Car ries t h e flow - cont r ol ind icat or , f low - con t r ol ackn ow ledg m en t , and Cov t ingoredge flowerag - conter of ol cut operat bit s.t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored Cisco Sy st ems, w or ide leader in netal w or king of f or6 6. t he I n t er n et . Prot ocol by I D— When set t o 0x 42ldw , ind icat es a decim v alue I n t ernHetew or krinnu g Tech Edes it ion , is a com ade m b ernologies — WhenHand set tbook o 0x ,01Four , indt hicat a value of 1.pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. La rg est Mast fra mere tsiz he e— t er m Car s, ries con cep t h et s, larg t echn est frologies, am e size an bit d devices s acr ossused t he DLSw in t oday connect ' s net w ion. orkTh ingis indu stfield ry . Lear is imp n how lem ent t o ed incor t o por ensur at eeint t her atnet t h ew or t wkin o end g t echn st at ions olog ies alwin ayt os a negot LAN/iat WAN e a frenv amireonm sizeent t o. Com plet be e u sed w it honnew a cir ancud itu pdat t h at ed does chapt n oterr equir s on secur e DLSw it y ,par st or t nage, er s t oopt r esegm ical net enwtorf rkames. in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all SS P gfl ags— Cont ainsr egar additdless ionalofinfor m atise. ion about t he SSP m essage. Flag d ef init ions ( bit 7 net w or kin p rof essionals, ex pert is t he most sig nificant bit , an d b it 0 is t he least sign ificant b it of t h e oct et ) ar e show n in Reader Table s w ill3 3obt 1.ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy le 3ic3pict - 1 ur . SSP Fl ag innitetions syst em s, pr ovid in g a m orTab e r ealist e of t he real-De w orf ld w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Bit Nam e Me a ni ng decisions for t h eir net w ork s. Posi t ion 7

SSPex

1 = Ex plor er m essage ( can ur each or icanr each) .

6 t hr oug h 0

Reser v ed None. Reserv ed f ield s ar e set t o 0 up on t ran smission an d ar e ignor ed upon r eceipt .

Circui t p ri orit y— Prov ides f or unsup por t ed, low , m edium , h ig h, an d highest cir cu it pr ior it ies in t he 3 low - or der b it s of t his by t e. At cir cuit st ar t t im e, each cir cuit end point pr ov ides pr iorit y in for m at ion t o it s cir cu it par t n er . Th e init iat or of t h e cir cuit ch ooses w hich circuit pr iorit y is ef fect ive f or t h e lif e of t h e cir cuit . I f t he pr iorit y is n ot im plem en t ed b y t he nod es, t h e un su ppor t ed pr iorit y is u sed. • •

Table of Content s

Ta rge t M AC a ddr e ss— Com bines w it h t he t ar get lin k SAP, or igin MAC addr ess, an d origin I ndex SAP t o defin e a logical end - t o- end associat ion called a dat a- link I D .

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco OrSystems, igi n MAC Inc.a dd re ss—

Ser v es as t he MAC ad dr ess of t h e or ig in end st at ion.

Or igi n LSAP— Ser v es as t he SAP of t he sour ce dev ice. Th e SAP is used t o logically ident ify t he t raf fic b ein g t ran sm it t ed.

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

I SBN: 705 -1 19 -2 Ta rge 1t 58 LSAP— Ser v es as t he SAP of t he d est inat ion dev ice. Pages: 11 28

Fra m e dir ect i on— Cont ains t he v alue 0 x0 1 f or f ram es sen t f r om t he or igin DLSw t o t he t ar get D LSw n ode, or 0 x0 2 f or f ram es sen t f r om t he t arg et DLSw t o t he or igin DLSw node. D LC h ea de r le ngt h — When set t o 0 for SNA and 0x 23 f or Net BI OS dat ag r ams, in dicat es a lengt h of 35 by t es. The Net BI OS header includes t he follow ing in for m at ion: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. - Access Cont r ol ( AC) f ield Con cise ovam er veiew s tof - Fr Con rolt echn ( FC) olog f ieldies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . - Dest inat ion MAC add r ess ( DA) New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP - Sour ce MAC ad dr ess ( SA) Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age - Rout ing I nf or mat ion ( RI ) field ( padded t o 18 by t es) Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . - Dest inat ion serv ice access point ( DSAP) I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net-w Sour or kince g pSAP r ofessionals ( SSAP) t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how at)e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . - LLC contt o r olincor f ieldpor ( UI Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, Or igi nt hDLC is book por is t I aD com — Work plet es in an d t and u p-em t o- dwat it he trhefeerorence igin tdat o t ahelink t op cor ics relat t hat or aret oessen for mt ial a 64 t o- bit all net w or circuit kin g pI D roft essionals, h at ident if ies r egar t hedless DLCofcirex cuit pert w ise. it h in a sin gle DLSw node. Th e cir cuit I D is u nique in a single D LSw n ode and is assig ned locally . The end - t o- end cir cuit is id en t ified b y a p air Reader w ill obt aint hat a g ,reat er un andat ding of kLAN WAN eten w or k ing, p gle ar t icu lar tlyo-ten h ed ofscircuit I Ds along w itder h tsthe a- lin I D s,and uniqu elynid t ify a sin endhar dwcircuit ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided . Each D LSw n ode m ust keep a t able of t h ese cir cu it I D pair s: one f or t he local endonof a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t he cir cuit an d one for t he r em ot e end of t he cir cu it . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag Or igi e isn also da t aext li nk endcorr ed nel otaonly t or—t oWork new snin et wor t andk em ing w concep it h t h et s,orbut iginalso DLCt opor old t er I D, tlegacy o for m a 64syst em bits,cir prcuit ovidIin D gt hat a mident or e r if ealist ies t ic hepict DLC ur cir e of cutithew it realhin wa or sing ld nleetDLSw w or k ing node. en vir The onm cirent cuit s in I D wishich pr of essionals un iq ue inoper a sing at e.leTools DLSwand andguisidassign elinesed f orlocally opt im.izing Th e en syst d-em t o- end per for circu m ance it is ident w ill incr if iedease by a pr odupair ct iv itofy cir an cu d im it Ipr Ds ovt e h at eff, iciency, along w help it h t he ingdtat hea-r link eader I Ds, m ake un iquely mor e ident in t elligent ify a single , cost - end eff icient - t o- end decisions circuit for. Each t h eir Dnet LSw w ork n ode s. m ust keep a t able of t h ese cir cu it I D pair s: one f or t he local end of t he cir cuit an d one for t he r em ot e end of t he cir cu it . Or igi n t ra nsport I D — I d en t ifies t he in divid ual TCP/ I P por t on a DLSw node. Values h ave only local signif ican ce. Each DLSw nod e m ust r eflect t he values, along w it h t he associat ed v alues for t he DLC p ort I D and t he d at a- lin k corr elat or , w hen ret ur n in g a m essage t o a

DLSw par t ner .

• •

Ta rge t d at a - lin k corr el at or — Work s in t and em w it h t h e t ar get D LC por t I D t o for m a 64bit cir cuit I D t hat ident if ies t he DLC cir cu it w it hin a sing le DLSw node. The cir cuit I D is un iq ue in a sing le DLSw node an d is assigned locally . The en d- t o- end circuit is ident ified by a p air of cir cuit I D s t hat , along w it h t h e dat a- link I D s, uniqu ely id en t if ies a single end - t oend cir cuit . Each DLSw nod e m ust k eep a t able of t h ese circuit I D p airs: one f or t he local end of t he cir cu it and on e for t he r emot e en d of t h e circuit . Table of Content s

I ndex Tra nspor t I D — I d en t ifies t he in divid ual TCP/ I P por t on a DLSw node. Values h ave on ly t he v alues, along w it h t he associat ed Cisco v alues Systems, for Inc. t he DLC p ort I D and t he d at a- lin k corr elat or , w hen ret ur n in g a m essage t o a DLSw par t ner .

I nt e rn local et w or ksig ingnificance. Te chnologie s H a ndbook Four thmu Editstion Each DLSw , node r ef lect By

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: • •

DLSw pr ov ides lin k layer ack now led gm ent s. What is m eant b y link lay er Table Content ackn ow of ledg m en st s? Why is t his adv ant ag eou s? I ndex

I nt e rn et k ing Te chnologie ndbook , Four tht Edit 2 :w or DLSw SSP u sess Hwahat t r anspor pr otion ocol? By

What ar e t he ad van t ages and

disadvInc. ant ag es of t his select ion? Cisco Systems, 3:

List and descr ibe t h e t hr ee oper at ional ph ases of D LSw .

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

4:

What pr ot ocols does DLSw supp or t ?

I SBN: 1- 58 705 -1 19 -2 11 28 is t h e nor m al Lay er 2 pr ocess em ployed w it hout DLSw ? 5Pages: : What

6:

DLSw defin es t wo m essage t y pes. Wh at ar e t h ey , w hich has t h e larg er header, and is t her e any t h in g in com mon b et w een t hem?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Part VI: Network Protocols Ch apt er 34 Open Sy st em I nt er con nect ion Pr ot ocols • •

Ch apt er 35 I n t er net Prot ocols Table of Content s

Ch apt er 36 I Pv 6 I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ch apt er 37 Net War e Pr ot ocols

By Cisco Systems, Inc.

Ch apt er 38 Ap pleTalk

Cher: aptCisco er 39 I BM Pub lish Press

Sy st em s Net w ork Archit ect ur e Pr ot ocols

Pub Ch Datapt e: Sep 1 1, 2et 003 er tem 40ber D ECn I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 34. Open System Interconnection Protocols • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

I nt r odu ce t he OSI pr ot ocol, used pr im ar ily t o facilit at e m ult iv en dor equ ip m en t int er operab ilit y .

By Cisco Systems, Inc.

PubDiscuss lish er: Cisco t hePress st r uct ur es

and f unct ioning of t h is pr ot ocol, fr om it s in t rod uct ion in t h e early

Pub 19Dat 80s. e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background The Op en Sy st em I nt er connect ion ( OSI ) p r ot ocol su it e is comp r ised of num erou s st andar d pr ot ocols t hat ar e based on t h e OSI r efer en ce mod el. Th ese p rot ocols ar e p art of an in t ern at ional pr ogr am t o dev elop dat a- net w ork ing pr ot ocols and ot her st an dar ds t h at f acilit at e m ult iv endor •equipm ent int Table of Content er operab ilit y s. Th e OSI p rog ram gr ew out of a need for int er nat ion al net w or kin g •st andar d s and I ndex is desig ned t o f acilit at e com m unicat ion bet w een har dw ar e and soft w ar e sy st em s Idespit nt e rn et or kfer ingen Teces chnologie s H a ndbook Four th Edit ion ewdif in un derly ing ar, ch it ect ur es. By Cisco Systems, Inc.

The OSI specif icat ion s w er e conceiv ed and imp lem ent ed by t w o in t ern at ional st and ard s or ganizat ion s: t he I n t er nat ion al Or gan iz at ion f or St and ard izat ion ( I SO) and t h e I nt ern at ional Pub lish er: Cisco Press Telecom m unicat ion Union –Telecom mu nicat ions St and ar ds Sect or ( I TU- T) . This chapt er p r ovides 1 1, 2 003 a suPub mmDat are:y Sep of tem t heber OSI pr ot ocol suit e an d illust r at es it s m app in g t o t h e gener al OSI r efer en ce I SBN: 158 705 -1 19 -2 m odel. Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

OSI Networking Protocols Figur e 34 - 1 illust r at es t he en t ir e OSI pr ot ocol suit e an d it s relat ion t o t h e layer s of t he OSI r ef erence m odel. Each com ponent of t his p rot ocol suit e is discu ssed b r ief ly in t h is ch apt er . The OSI r ou t in g pr ot ocols are ad dr essed in m or e det ail in Ch apt er 48 , " Op en Sy st em I n t er connect ion •( OSI ) Rout ing Table Content Pr otofocols. " s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 3 4 -1 . Th e OSI Pr ot ocol Su it e M ap s t o All La ye r s of t h e O SI Re f er e nce M odel Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions OSI Physical Link t o en su re con cept and compData r eh en sion andlayers r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy The OSIs, pr ocolin suit t s nu er ous darreald mediaocols t heent p hy an d syst em prot ovid g a emsup or epor r ealist icmpict ur e st ofan t he w or ldaccess n et w orpkrot ing en viratonm s sical in w hich dat link lay eroper s. The e varand iet ygu ofidmelines ed ia- access pr ot ocols suem pporper t edforinmtance h e OSI pr ofaessionals at e.wid Tools f or opt im izing syst w illp rot incrocol easesu it e allow pr ot suit o exist easily alon OSImon e same w ork, cost media. Su ppor t ed pr odusctot ivher it y an d ocol im pr ov e es effticiency, help ing t hegside r eader aket hmor e in t net elligent - eff icient m ed ia- access ot ocols inclu decisions for t hpreir net w ork s. de I EEE 8 02. 2 LLC, I EEE 8 02. 3 , Tok en Ring / I EEE 80 2. 5, Fiber Dist r ibut ed Dat a I n t er f ace ( FD DI ) , and X. 25.

OSI Network Layer

The OSI pr ot ocol suit e specifies t w o r out in g p r ot ocols at t he net w ork lay er: En d Sy st em- t oI nt er mediat e Syst em ( ES- I S) and I nt erm ediat e Sy st em- t o- I n t erm ediat e Sy st em ( I S- I S) . I n addit ion, t he OSI su it e imp lem ent s t wo t y pes of net w or k ser v ices: connect ionless ser vice and connect ion- or ien t ed serv ice.

OSI Layer Standards • Table of Content s •

I ndex

n eaddit t o tTe hechnologie st andars dHsa ndbook sp ecif ying h eEdit OSI II nt rn et wion or k ing , Fourtth ion n et w or k lay er pr ot ocols and ser vices, t he follow ing docum ent s d escr ibe ot her OSI net w or k layer specif icat ion s: By Cisco Systems, Inc. PubI lish Cisco Press SOer:8 6 48— This

st andar d defin es t he int er nal or g anizat ion of t he net w or k lay er ( I ONL) , layer in t o t h ree d ist inct su blay er s t o suppor t diff erent subn w58 or705 k t-1 y pes. I SBN:et119 -2

Pub w Dat hich e: Sep divid temes bert 1he 1, 2net 003w or k

Pages: 11 28

I SO 8 3 4 8 — This st andar d defin es net w ork lay er add ressin g an d d escr ibes t he conn ect ionor ien t ed an d conn ect ionless ser v ices pr ov ided b y t he OSI net w or k layer . I SO TR 9 5 7 5 — This st andar d descr ibes t h e fr am ewor k , concept s, and t er m in ology used in r elat ion t o OSI r out ing p rot ocols. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

OSI Connectionless Network Service Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom OSI conn ect ionless net nov ice t o ex pert . w or k ser v ice is im plem en t ed b y using t he Connect ionless Net w or k Pr ot ocol ( CLNP) and Connect ionless Net w or k Ser v ice ( CLNS) . CLNP and CLNS are descr ibed in t he I SO New 84chapt 73 ster andar s include d. cov erag e of im por t ant t opics like VoI P and EAP CLNPCov is an erag OSI e of netcut w or t ing k layer edgeprt echn ot ocol ologies t h at car lik er ies optuical pper n et - layer wor kding at aand an dster orr age or indicat ions ov er connect ionless link s. CLNP p rov ides t he in t erf ace bet w een t he Connect ionless Net w or k Serv ice Autand h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . ( CLNS) u pper lay er s. I n t ern pr et w k in gnet Tech Hand book h Ed it ion , iseravia com pr ehensive refer ence t hat CLNS ovorides w ornologies k layer serv ices t o, t Four he t rtanspor t lay CLNP. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. CLNS does n otMast per er for tmheconn t er mect s, ion conset ceputps,ort echn t ermologies, inat ion an because d devices pat hused s ar eindet t oday erm'ined s net w ork ing indu st ry . en independ Lear t lynfor how each t o incor pack por et t at hat e int is ter r ansm net w or it t kin ed g t htrou echn gholog a n ies et win ortko. aThis LAN/ cont WAN rastenv s wiritonm h ent . Comnect Con pletion e w-itMode h newNet anwdorukpdat Serv edice chapt ( CMNS) er s on . secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Inet n addit ion, pr ovid esr egar b est dless - eff or of t d ex elivpert er yise. , w hich means t hat no g uar ant ee ex ist s t hat d at a w or kin g pCLNS rof essionals, w ill not be lost , cor ru pt ed, misor dered, or du plicat ed. CLNS relies on t ran sp ort lay er pr ot ocols t o Reader per for ms er w ill rorobt det ain ectaion g reat andercor unrect der st ion. an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tOSI o enConnection-Oriented su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Network Service Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich OSI conn ect ion- orient ed net w or k ser v ice is im plem en t ed by using t he Connect ion- Or ien t ed pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Net w ork Prot ocol ( CONP) and Conn ect ion- Mode Net w ork Ser v ice ( CMNS) . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions forOSI t h eir wkork s. pr ot ocol t h at car r ies u pper - layer d at a an d er r or indicat ions ov er CONP is an netnet w or layer connect ion- or ien t ed link s. CONP is based on t h e X. 25 Pack et - Lay er Pr ot ocol ( PLP) and is descr ibed in t he I SO 8208 st and ar d, " X. 25 Packet - Layer Pr ot ocol f or DTE." CONP pr ov ides t he int er f ace b et ween CMNS an d upper lay ers. I t is a n et w or k lay er ser vice t h at act s as t h e int er face bet w een t h e t r anspor t lay er and CONP, and it is describ ed in t he I SO 887 8

st andar d . CMNS per for m s fu nct ions r elat ed t o t he ex plicit est ab lishm ent of pat hs bet w een comm un icat in g t r anspor t lay er ent it ies. These fun ct ion s include conn ect ion set u p, m aint enan ce, an d t er m inat ion. CMNS also pr ov id es a m ech anism for requ est ing a sp ecific q ualit y of ser v ice ( QoS) . This cont r ast s w it h CLNS. •

Table of Content s

Network Layer • I ndex Addressing I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

OSI n et wor k lay er addr essing is im plem en t ed b y using t w o t y pes of hier arch ical ad dr esses: By Cisco Systems, Inc. net w or k ser v ice access point addr esses and net w or k ent it y t it les. Cisco AnetPub w lish or ker:ser v icePress access p oint ( NSAP) is a concep t ual point on t he bou ndar y b et w een t h e Pub e: Sep tem tber 1 1, 2 003 net w or Dat k and t he r anspor t lay er s. Th e NSAP is t he locat ion at wh ich OSI net w ork ser vices ar e pr ov ided I SBN: t o 1-t he 58 705 t ran -1 19 spor -2 t lay er . Each t r ansp ort layer ent it y is assign ed a sing le NSAP, w hich is indiv idually ad28dr essed in an OSI int er net w or k using NSAP add r esses. Pages: 11

Figur e 34 - 2 illust r at es t he for m at of t h e OSI NSAP ad dr ess, w hich ident ifies ind iv idu al NSAPs.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Figu r e 3 4 -2 . Th e OSI NSAP Add r ess I s Assi gne d t o Ea ch Tr an sp or t essent ial an d cu t t ing- edg e t ech nologies.

La ye r En t i t y

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ryAddress NSAP . Lear n how Fields t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, ando speed, t h is ess book is sa exist com plet e an u pt o- dain at ep art r ef er( Ience t o t he ics t hat essen t o all Tw NSAP Addr field : t he initdial d om DP) and t het op d omain - spare ecific p arttial ( DSP) . net w or kin g p rof essionals, r egar dless of ex pert ise. The I DP field is divid ed int o t w o p art s: t he au t hor it y f orm at ident ifier ( AFI ) and t h e init ial Reader w ill obt a g) .reat un der st anes ding ofmLAN and n etstwror k ur ing, p ar icu lar h et h e I D I dom ains ident ifierain ( I DI Th eerAFI pr ovid in for at ion ab WAN out t he uct e an d tcont enlyt tof har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on and DSP fields, such as w het her t he I D I is of var iable leng t h an d wh et her t he D SP uses decimal a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions or b in ary not at ion. The I DI specifies t he ent it y t hat can assign values t o t he DSP p ort ion of t he tNSAP o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ad dr ess. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst s, is prsub oviddivid in g aedmint or oe fou r ealist ic tpict t he realor ld nsib et w k ing vir in onm s in. The w hich The em D SP r par s b yurteheofau t hor it y w r espon leorfor it s en adm ist rent at ion pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Add ress Adm inist r ion f ield s allow for t he f ur t her adm inist r at ion of ad dr essing by ad ding a pr odu ct au iv ittyhor anitdy im pr ov e eff helpating r eader m ake e inttoelligent costit-ies. eff icient second ident ifier aniciency, d b y deleg ingt he addr ess adm inistmor rat ion subau,t hor Th e Area decisions for t h eir net w ork s. field id en t ifies t he sp ecific ar ea w it hin a dom ain an d is u sed for rou t ing pu rp oses. The St at ion field id en t ifies a specific st at ion w it hin an ar ea an d also is used f or r out ing pu rp oses. The Select or f ield pr ov id es t he specific n- select or w it h in a st at ion an d, m uch like t he ot her f ield s, is used for r out in g p ur poses. The r eser ved n- select or 00 ident if ies t he ad dr ess as a net w or k en t it y t it le ( NET) .

End-System NSAPs An OSI end syst em ( ES) of t en h as m ult iple NSAP ad dr esses, on e for each t r anspor t ent it y t hat it cont ains. I f t his is t he case, t he NSAP ad dr ess f or each t ran sp ort ent it y u su ally d iff er s on ly in t h e last by t e ( called t he n- select or ) . Figur e 34 - 3 illust r at es t he relat ionship bet w een a t ran sp ort ent it y , t he NSAP, and t he n et wor k ser vice. •

Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Figu r e 3 4 -3 . Th e NSAP Pr ov ide s a Lin k Be t w e en a Tr a nspor t En t i t y a nd a Ne t w or k Ser v ice

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, A n etspeed, wor k ent it ybook t it le is ( NET) is plet used t o dident heenet k layt oert he of at op syst w itare houessen t associat and t h is a com e an u p- tify o- dt at r efw eror ence icsem t hat t ial t oing all tnet hatw syst em w it h a specific t r anspor t layer ent it y ( as an NSAP addr ess does) . NETs ar e u sefu l f or or kin g p rof essionals, r egar dless of ex pert ise. add ressin g in t er m ediat e sy st em s ( I Ss) , such as rou t ers, t h at d o not int er face w it h t he t ran sp ort lay er . An S can havae gareat sing NET mu lt ip le if itWAN p art icipat eskin m ult Reader s wI ill obt ain erleun deror st an ding of NETs, LAN and n et w or ing, p ariple t icuar lareas ly t or he dom ains. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov e is also extTransport end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy OSIerag Protocols Layer syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease The OSI pr ot ocol suit e im plem en t s t w o t yp es of ser vices at t h e t r anspor t lay er: connect ionpr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient or ien t ed t r anspor t ser v ice an d con nect ion less t r anspor t ser vice. decisions for t h eir net w ork s. Five conn ect ion- or ient ed t r anspor t lay er pr ot ocols ex ist in t he OSI suit e, r anging f rom Tran spor t Pr ot ocol Class 0 t hr oug h Tr ansp ort Pr ot ocol Class 4. Connect ionless t ran sp ort ser v ice is supp ort ed only b y Tr anspor t Pr ot ocol Class 4 . Tr anspor t Pr ot ocol Class 0 ( TP0 ) , t he sim plest OSI t ran sp or t pr ot ocol, p er for m s segm en t at ion

and r eassemb ly fu nct ions. TP0 requ ires conn ect ion- or ient ed net w ork ser vice. Tr anspor t Pr ot ocol Class 1 ( TP1 ) p er for m s segm en t at ion and reassem bly , an d of fer s basic err or r ecov ery . TP1 seq uences pr ot ocol dat a unit s ( PDUs) and w ill r et r ansm it PD Us or reinit iat e t he connect ion if an excessiv e nu mb er of PDUs are unack now led ged. TP1 r equir es con nect ion or ien t ed n et w or k serv ice. Tr anspor t Pr ot ocol Class 2 ( TP2 ) p er for m s segm en t at ion and reassem bly , as w ell as m ult ip lex ing • Table of Content s and dem ult iplex in g of d at a st r eams over a sin gle v ir t u al circuit . TP2 r equir es connect ion- or ien t ed •net w or k ser vIice. ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Tr anspor t Pr ot ocol By Cisco Systems, Inc. Class 3 ( TP3 ) of fer s basic err or r ecov er y and per for m s seg ment at ion an d r eassemb ly, in add it ion t o m ult iplexin g an d d em u lt ip lex ing of dat a st ream s ov er a single v ir t ual circuit . TP3 also sequences PDUs and r et r ansmit s t hem or r ein it iat es t he conn ect ion if an Pub lish er: Cisco Press excessiv e nu mb er are u nack now led ged. TP3 r eq uir es con nect ion - orient ed net w or k ser v ice. Pub Dat e: Sep tem ber 1 1, 2 003

I SBN: 58ocol 705 -1Class 19 -2 4 ( TP4 ) of fer s basic err or r ecov er y, perf or ms segm ent at ion and Tr anspor t Pr1-ot Pages: 28 d su pplies m ult iplexing an d d em ult ip lex ing of dat a st r eam s ov er a single v irt ual r eassemb ly,11an circuit . TP4 sequences PDUs and r et r ansmit s t hem or r ein it iat es t he conn ect ion if an ex cessiv e nu mb er are unack now led ged. TP4 pr ov ides r eliable t r an sp ort ser v ice an d fun ct ion s w it h eit h er connect ion- or ien t ed or con nect ion less net w or k ser v ice. I t is based on t he Tran sm ission Con t r ol Pr ot ocol ( TCP) in t he I nt er net Pr ot ocols suit e and is t h e only OSI pr ot ocol class t h at sup por t s connect ionless n et wor The u pdat ed edit ion ofk t ser he vice. b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

essent ial an d cu t t ing- edg e t ech nologies.

OSI Con Protocols Session Layer cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing

pr ofession als at all lev els, f rom nov ice t o ex pert . The session layer im plem en t at ion of t he OSI pr ot ocol suit e consist s of a session pr ot ocol and a session serchapt vice. er The sessioncov pr erag ot ocol allow s session - ser v ice ser P s (and SS- EAP u ser s) t o com m un icat e New s include e of im por t ant t opics likeuVoI w it h t he session ser v ice. An SS- user is an en t it y t hat r eq uest s t he serv ices of t he session lay er . Such Cov r eq uest mad e at sessionvice access s et ( SSAPs) , and eragse are of cut t ing edge t echnser ologies lik e optpoin icalt n wor k ing and SSst oruser ages are uniqu ely ident if ied by u sin g an SSAP addr ess. Figur e 34 - 4 sh ows t he r elat ion sh ip b et ween t he SS- u ser , Aut h ored by CiscoprSy st ems, w or ldwsession ide leader net w or king f or t he I n t er n et . t he SSAP, t he session ot ocol, and t he ser vin ice. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. t he t er m s,La con t s, t echn ologies, an d de devices used net orkion ing Figu r e 3 4Mast -4 . er Sessi on yecep r Fun ct i ons Pr ovi Ser v ice int ot oday Pr e' sse ntwat indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . La ye r Fun ct ions v ia a n SSAP Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

•

Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Session ser v ice p rov ides f our basic serv ices t o SS- user s. Fir st , it est ablishes and t er minat es New chapt ereen s include covs erag im por t antt he t opics VoI P and connect ions b et w SS- u ser and esyof nchr onizes d at alike ex ch ange betEAP w een t hem . Secon d, it per for m s v ariou s negot iat ions for t h e use of session lay er t ok en s, w hich t h e SS- user m ust Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age possess t o begin comm u nicat in g. Th ir d , it inser t s syn ch ron izat ion p oint s in t r ansm it t ed dat a t hat allow Aut t heh session o be rSy ecov ered w inort he enleader t of er ror orwin er r upf tor ions. ored by tCisco st ems, ldwev ide in snet ort king t he Fin I n tally er n,etit. enables SSusers t o int er r upt a session and r esu me it lat er at a specif ic point . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Session is dg ef in t h e I SO 83derst 06 stand andar in t he X. 21 endat ioning . enables ser net vwice or kin p ined r ofessionals t o un andd and im plem en tI TUcontTem por5arr ecomm y int er net w ork The session pr ot ocol is d ef ined in t he I SO 83 07 st andar d and in t he I TUT X. 22 5 t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing rindu ecom m .enLear dat ion. A connect verer sion ofort he pr oties ocolinis in t henv e I ir SO 95ent 48 . st ry n how t o incorionless por at e int net w kin session g t echn olog t ospecified a LAN/ WAN onm st andar d . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

OSI Protocols Presentation Layer

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on The p r esent at ion layer im plem en t at ion of t he OSI p r ot ocol su it e consist s of a pr esent at ion a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions pr ot ocol an d a pr esent at ion serv ice. The pr esen t at ion p rot ocol en ables pr esent at ion - ser vice t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . users ( PS- users) t o com mu nicat e w it h t he p resen t at ion ser vice. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, prisovid g itay mt hat or e requ r ealist e vofices t heofrealld n et or klay ingeren virch onm ent s ins w A PSu ser an in ent estics pict t h e ur ser t h e wproresent atwion . Su r equest arhich e pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease m ade at pr esent at ion - ser v ice access p oint s ( PSAPs) . PS- u ser s ar e un iq uely ident ified by using pr odu ad ct ivdritesses. y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient PSAP decisions for t h eir net w ork s. Pr esent at ion ser v ice negot iat es t r ansfer sy nt ax an d t r an slat es dat a t o and fr om t h e t r ansfer syn t ax for PS- user s, w hich r ep resen t d at a u sing d if fer en t sy nt ax es. The pr esen t at ion ser vice is used by t w o PS- user s t o agr ee upon t h e t r ansfer syn t ax t h at w ill be u sed . When a t r ansf er syn t ax is agr eed u pon, pr esent at ion- ser vice ent it ies m ust t r anslat e t h e dat a fr om t h e PS- user t o t he cor r ect t r ansfer sy nt ax .

The OSI pr esent at ion lay er ser v ice is d ef ined in t h e I SO 88 22 st andar d and in t he I TU- T X. 21 6 r ecom m en dat ion. The OSI pr esent at ion pr ot ocol is d ef ined in t he I SO 88 23 st andar d and in t he I TU- T X. 226 r ecom m endat ion. A conn ect ionless ver sion of t h e pr esent at ion pr ot ocol is specified in t he I SO 957 6 st an dar d.

OSI Protocols Application Layer • Table of Content s •

I ndex

The ap plicat ion lay er imp lem ent at ion of t he OSI pr ot ocol suit e consist s of v arious applicat ion I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion ent it ies. An ap plicat ion ent it y is t he par t of an ap plicat ion p rocess t hat is r elevan t t o t he By Cisco Systems, oper at ion of t heInc. OSI pr ot ocol su it e. An ap plicat ion ent it y is com posed of t he user elem ent and t he applicat ion ser vice elem ent ( ASE) . Pub lish er: Cisco Press

ThePub u ser is 1t h1,e2 par Datelement e: Sep tem ber 003 t of an app licat ion ent it y t h at u ses ASEs t o sat isfy t h e comm un icat ion needs Iof t h e1- applicat SBN: 58 705 -1 19ion -2 pr ocess. The ASE is t he par t of an app licat ion ent it y t h at pr ov ides ser v ices t o user elem ent s and , t h er efor e, t o ap plicat ion p rocesses. ASEs also p rov ide in t er f aces Pages: 11 28 t o t he low er OSI lay er s. Figur e 34 - 5 p or t ray s t h e comp osit ion of a sing le applicat ion pr ocess ( com posed of t h e applicat ion ent it y, t he user elem ent , an d t he ASEs) and it s r elat ion t o t he PSAP and pr esen t at ion ser vice.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ialFigu an d cu edg t echAppl nologies. r et t ing3 4 -5 . eAn icat ion Pr ocess Rel ie s on t he PSAP a nd

Pr ese nt a t i on Se r vi ce Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich ASEs f all int o one of t h e t w o f ollowin g classif icat ion s: comm on- applicat ion serv ice elem ent s pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease ( CASEs) and specif ic- ap plicat ion serv ice elem en t s ( SASEs) . Bot h of t h ese m igh t be pr esent in a pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient single ap plicat ion ent it y . decisions for t h eir net w ork s.

Common-Application Service Elements Com m on- ap plicat ion ser v ice elem en t s ( CASEs) ar e ASEs t h at p rov ide serv ices used by a w ide

v ariet y of ap plicat ion pr ocesses. I n m any cases, mu lt ip le CASEs are u sed by a sin gle app licat ion ent it y . The follow in g four CASEs ar e d ef ined in t he OSI specif icat ion : Associ at i on con t rol ser vi ce el em e nt ( ACS E) — Cr eat es associat ion s bet w een t w o app licat ion en t it ies in p repar at ion for applicat ion- t o- app licat ion comm u nicat ion • •

Re m ot e ope ra t ion s se rv i ce e le m en t ( R OSE) — I m plem en t s a requ est - r eply m ech anism Content s t hat perTable m it s ofvar ious rem ot e oper at ions acr oss an applicat ion associat ion est ablish ed by t he I ndex ACSE

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

ReSystems, li ab le t Inc. r an sf e r By Cisco

se rv ice e le m ent ( RTSE) — Allow s ASEs t o r eliab ly t r ansfer m essages w hile pr eser v in g t he t r anspar ency of com plex low er - layer f acilit ies

Pub lish er: Cisco Press

Com m i t m e nt , con cu rre nce , a nd re cov e ry ser vi ce el em e nt s ( CCRSE) — Coor dinat es applicat ion ent it ies

Pub Dat e: Sep ber 1 g 1, m 2 003 dialogu estem amon u lt ip le I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Specific-Application Service Elements Specific- applicat ion ser vice elem ent s ( SASEs) ar e ASEs t h at p rov ide ser vices used only b y a The u pdat specif ic applicat ed edition ionprofocess, t he b est such - selling as fileallt r ansfer in- one, dat net ab w ork aseing access, r ef erence an d pord roverides en tcover ry , amage on gof essent ot her s.ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom OSI Protocols Application Processes nov ice t o ex pert . An applicat ion pr is t he elem anpor app licat ion t hat ovP id and es t he int er face b et w een t he New chapt erocess s include cov eragen e tofofim t ant t opics likepr VoI EAP app licat ion it self and t h e OSI app licat ion layer . Som e of t he st an dar d OSI app licat ion pr ocesses include Covt he erag f ollow e of ing cut:t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Com m on m ana ge m en t - i nfor m at i on p rot ocol ( CM I P) — Per f orm s n et w or k - m anagem en t I n t ernfuetnct w or ions, k in gallow Teching nologies t he exHand ch ange book of, m Four an agement t h Ed it ioninf , isorm a com at ion pr bet ehensive w een ESs referand ence t hat enables m anagem net w or kin entgstpat r ofessionals ion s. CMI P tis o specified un derst and in tan h ed I im TU-plem T X.7 en00 t cont r ecom emm por enar dat y int ionerand net w isork ing t echnologies. fu nct ionally Mastsimilar er t he t oertm hes,Sim conple cepNet t s, w t echn or k ologies, Manag em anent d devices Pr ot ocolused ( SNMP) in t oday an d' sNet net View w ork . ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . D ireect orh ynew se rvan ice ( D S)ed —chapt Ser v es d ist r ibut ect ory t hatnet is w used f or Com plet w it ds u pdat er sas ona secur it y , ed st ordir age, opt ical or k in g, node scalabilit y, ident if icat ion and add ressin g in OSI in t ern et w or k s. DS is sp ecified in t h e I TUT X.5 00 and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all r ecom en essionals, dat ion. net w or kin g m p rof r egar dless of ex pert ise. Filsewtill raobt nsfe r, aaccess, m st a na m ent ( FTAM) — Prov ansfer Reader ain g reat er an undder an ge ding of LAN and WAN n etides w or kf ileing,t r p ar t icuserv lar lyice t h eand r ibut edocols, file- access har dwdist ar e, pr ot and serfacilit v icesies. inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Meressa gecept hancomp dli ng syst e m and ( MHrS) sp or tr esou m echr ces anism ic . t o en su con r eh en sion et — en tProv ion, ides and aadt ran dit ional f or for fu rtelect her ron st udy m essaging ionnsotand ot her ap plicat ionksing by concep u sing st or but e- andf ort owar v ices. Cov erag e is also ap extplicat end ed only t o new n et wor t s, also oldderser , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich V ir t ua l toper er mat ina pr ot ocol ( Vid TP ) — Prov t er min al emu ionfort hmatance allow s aincr com pu t er pr of essionals e. l Tools and gu elines f or ides opt im izing syst emlat per w ill ease syst em t o appear t o a r em ot e ES as if it w ere a dir ect ly at t ached t er m inal. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What ar e t he t w o r out ing p rot ocols specif ied in t he OSI suit e?

2:

I ndex ibe t he OSI con nect ion less net w or k pr ot ocol. Descr

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : Descr By Cisco Systems, Inc.ibe 4:

t he OSI con nect ion - orient ed net w or k pr ot ocol.

How ar e r equest s t o ser vices at t he session lay er m ade w it hin OSI pr ot ocols?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

Descr ibe com mon - applicat ion ser vice elem ent s ( CASEs) .

I SBN: 1- 58 705 -1 19 -2 Pages: 28 e 6 : 11Nam

some of t he m edia t y pes t h at t h e OSI p rot ocol su it e su ppor t s.

7:

Why was t he OSI pr ot ocol suit e cr eat ed?

8:

Descr ibe t he session lay er pr ot ocols w it hin t he OSI pr ot ocol suit e.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of ibe edg t he eprtesen t at ion lay er pr ot ocols of t he OSI pr ot ocol suit e. essent ial9 :an dDescr cu t t ingech nologies. 1 0 : What ar e t he t w o t y pes of ASEs? Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 35. Internet Protocols Obj e ct i ve s • •

Table of Content s

I nt r odu ce t he I P p rot ocol, on e of t he m ost pr olif ic and pop ular pr ot ocols used t oday . I ndex

I nt e rn Discuss et w or k ingt he Te chnologie H aand ndbook Four th Edit st r uct urses ad,dr essing ofiont his

pr ot ocol.

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background The I n t er net pr ot ocols are t he w or ld' s m ost popu lar open- sy st em ( nonp rop riet ar y) pr ot ocol suit e because t hey can be u sed t o com m unicat e acr oss any set of int er con nect ed net w or ks and ar e equally w ell suit ed f or LAN and WAN com m unicat ions. Th e I n t ern et pr ot ocols consist of a suit e of •com mu nicat ion Table of Content p rot ocols, sof w hich t he t w o best k now n are t he Tr ansm ission Cont r ol Pr ot ocol •( TCP) and t he I ndex I n t ern et Pr ot ocol ( I P) . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

The I n t er net pr ot ocol suit e not only in clud es low er - layer p rot ocols ( such as TCP and I P) , bu t it By Cisco Systems, Inc. also specif ies com m on applicat ions such as elect r onic m ail, t erm inal em ulat ion , and file t r an sf er . This chap t er pr ov id es a br oad int r odu ct ion t o sp ecificat ions t hat com pr ise t he I n t er net pr ot ocols. Pub lish er: Cisco Press Discussions in clu de I P ad dr essing and k ey upper - lay er p r ot ocols u sed in t he I nt er net . Specific tem ber 1 1, 2 003 r outPub ingDat pre:otSep ocols ar e add ressed ind iv idu ally in Par t VI I , " Rout ing Pr ot ocols. " I SBN: 1- 58 705 -1 19 -2

I nt er net Pages: p rot 11ocols 28 w er e fir st dev elop ed in t he m id- 1 970 s, w hen t h e Defense Adv anced Resear ch Pr oject s Agency ( DARPA) b ecam e int er est ed in est ablish ing a p ack et - swit ched net w or k t hat w ould facilit at e comm u nicat ion b et w een d issim ilar com pu t er sy st ems at r esear ch in st it u t ions. Wit h t he g oal of het er ogeneous conn ect iv it y in m ind , DARPA fu nded research by St an for d Univer sit y and Bolt , Beran ek , an d New m an ( BBN) . The r esult of t h is developm ent ef for t w as t he IThe nt erunet p ed rot ocol su itof e, tcom in t he latine one 197 0s. pdat edit ion he bplet est -ed selling allnet w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. TCP/ I P lat er w as in clu ded w it h Berk eley Sof t w ar e Dist r ib ut ion ( BSD) UNI X an d h as sin ce becom e t he foun dat ion on wh ich t h e I nt ern et and t h e Wor ld Wid e Web ( WW W) ar e b ased. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Docum ent at ion ofpert t he. I n t er net pr ot ocols ( including new or rev ised pr ot ocols) and policies ar e nov ice t o ex specif ied in t ech nical r ep ort s called Req uest For Com m ent s ( RFCs) , wh ich ar e pu blish ed an d t h en r ev iew ed and analy b y tcov he Ierag n t eren et it y.t opics Prot ocol entEAP s ar e p ublished in t h e New chapt er s zed include of comm im por tun ant like ref VoIinPem and new RFCs. To illust r at e t he scope of t h e I nt er net pr ot ocols, Figur e 35 - 1 m ap s m any of t he pr ot ocols of t he t er tnet ot ocol suitologies e and tlik h eir corical r espon dingk ing OSI and lay ers. is chapt er Cov erag e ofI ncut ing pr edge t echn e opt n et wor st or Th age add resses t he basic elem ent s an d operat ion s of t hese and ot her k ey I n t ern et pr ot ocols. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables p r er ofessionals t o ocol un derst and an enpl t cont porng ar ye int net w ork ing l Figu r enet 3w 5 or -1kin . Ignt n et Pr ot s Spa n dt himeplem Com et eemRa oferOSI M ode t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing La ye r s indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

•

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Internet Protocol The I n t er net Prot ocol ( I P) is a net w ork lay er ( Lay er 3) pr ot ocol t h at cont ains addr essing inf or mat ion and som e cont r ol inf orm at ion t hat enables pack et s t o b e r out ed. I P is docum en t ed in RFC 791 an d i t he pr imar y n et w or k lay er pr ot ocol in t he I nt er net p rot ocol su it e. Alon g w it h t h e Tran sm ission Con t •Pr ot ocol ( TCP) Table Content , I Pofr ep resens t s t h e heart of t he I n t ern et pr ot ocols. I P has t wo pr im ary responsibilit ies •pr ov iding connect I ndex ionless, best - eff ort deliver y of dat ag r ams t hr ough an int er net w ork ; and pr ov id ing Ifrnt e rn et w or ing Te s H ably ndbook , Four Edit ion ag ment atk ion anchnologie d r eassem of dat ag th r ams t o supp or t dat a link s w it h diff er ent m axim um t r ansm unit By Cisco ission Systems, Inc.( MTU) sizes. Pub lish er: Cisco Press

IP Pub Packet Dat e: SepFormat tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

An I P Pages: pack et11cont ains sev er al t y pes of inf or m at ion , as illust r at ed in Figur e 35 - 2. 28

Figu r e 3 5 -2 . Four t e e n Fi el ds Com pr i se a n I P Packe t The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on The f ollow in g d iscussion d escr ibes t he I P packet field s illu st rat ed in Figur e 35 - 2: a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also I ext endes ed t he n otvonly t o of new et wor concep t s, but also t o old er , legacy V e rsion— n dicat ersion I P ncur rentklying used . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper e. hTools and id elines or dat opt agr im izing syst emlengt per for m ance incr I P he a de r l eat ngt ( I H L) — gu I n dicat es tfhe am header h in 32 - bitw ill w or ds.ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions Ty pefor - oft hse eirrvnet i cew— orkSpecif s. ies h ow an upp er - lay er pr ot ocol w ould lik e a cur rent dat ag ram t o b e han dled , and assig ns d at agr am s v arious lev els of im por t an ce. Tot a l le ngt h — Specif ies t h e len gt h , in b yt es, of t h e en t ir e I P pack et , inclu ding t he dat a and t h header .

I de nt i fi ca t i on— Cont ains an in t eg er t hat ident ifies t he cu rr ent dat ag ram . Th is field is u sed t o help piece t og et her dat ag ram fr agm ent s. Fla gs— Consist s of a 3 - bit f ield of w hich t he t w o low - or d er ( least - significant ) bit s con t rol fr ag ment at ion . The low - or der b it specif ies wh et her t he p ack et can be f r agm en t ed. The mid dle specif ies w h et h er t he p ack et is t h e last f rag ment in a series of f rag ment ed pack et s. The t hir d o high - or der bit is not used . •

Table of Content s Fra gm en t of fset — I n dicat es t he posit ion of t he f r agm en t 's dat a r elat ive t o t h e beginn in g of t dat a in Itndex he or iginal dat agr am , w hich allow s t he dest inat ion I P pr ocess t o pr oper ly r econst r uct I nt e rn or et w or k ingdTe iginal atchnologie agr am . s H a ndbook , Four th Edit ion •

By Cisco Systems, Inc.

Tim e - t o- li ve — Maint ains a count er t h at g rad ually decrem ent s d own t o zero, at w hich point t h dat ag r am is discar d ed . This k eep s packet s f r om looping endlessly . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

P rot ocol— I n dicat es wh ich up per - lay er pr ot ocol r eceiv es in com ing pack et s aft er I P pr ocessin g I SBN: 1- 58 com plet e. 705 -1 19 -2 Pages: 11 28

H e ade r che ck sum — Helps en su re I P header int egr it y . Sou rce ad dre ss— Specif ies t h e sen ding nod e. D e st i na t ion a ddr ess— Specif ies t h e r eceiving n ode. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essentOpt ial ions— an d cu tAllow t ing- edg s I Pet toech supnologies. por t v ar iou s opt ion s, su ch as secu r it y. D a t a— Cont ains upp er - lay er in for m at ion. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

IP Addressing New chapt er s include

cov erag e of im por t ant t opics like VoI P and EAP

erag ing n etgwor k ing eand stegr or age As w itCov h any oteh of er cut nettw orkedge lay ert echn pr ot ologies ocol, t helikIeP opt addical ressin schem is int al t o t he p rocess of r out ing I P d at agr am s t hr oug h an in t er net w or k . Each I P add ress has specific com ponent s and follow Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . basic f orm at . These I P addr esses can be subd ivided and used t o cr eat e addr esses for su bnet w or ks, discussed in m or e d et ail lat er in t his ch apt er. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Each host on a TCP/ I P n et w or k is assigned a u nique 3 2- b it logical add ress t hat is div ided in t o t w o t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing m ain p ar t s: t he net w ork n um ber and t h e host n um ber . The n et wor k n um ber ident if ies a net w or k an indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . m ust b e assig ned b y t he I nt er net Net w or k I nf orm at ion Cent er ( I n t er NI C) if t he net w or k is t o be par Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, t he I n t er n et . An I nt er net ser vice p rov ider ( I SP) can obt ain block s of net w ork addr esses f rom t he and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all I nt er NI C and can it self assign ad dr ess space as n ecessar y . The h ost nu m ber ident ifies a host on a net w or kin g p rof essionals, r egar dless of ex pert ise. net w or k and is assig ned b y t he local n et wor k ad min ist r at or . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on IP a bAddress r oad r ang eFormat of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov ext end n otped only ing concep t s,dot but also rtep o old er ,t ed legacy The erag 3 2- beitisI Palso ad dr ess is ed g rou 8 bt oit snew at an tet imwor e, ksepar at ed by s and resen in decimal for syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in w,hich ( k now n as dot t ed decimal not at ion) . Each bit in t he oct et has a binar y w eight ( 128 , 64 , 32 16 , 8, 4 pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease 1) . The m inim um v alue f or an oct et is 0, and t he m ax imu m v alue f or an oct et is 255 . Figur e 35 - 3 pr odurat ct es iv ittyhe anbasic d im pr ov eateffoficiency, helpess. ing t he r eader m ake mor e in t elligent , cost - eff icient illust f orm an I P addr decisions for t h eir net w ork s.

Figu r e 3 5 -3 . An I P Addr e ss Con si st s of 3 2 Bi t s, Gr oup ed in t o 4 O ct et s

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Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 IP Address Classes Pages: 11 28

I P ad dr essing su ppor t s f ive diff er ent addr ess classes: A, B, C, D, an d E. On ly classes A, B, and C ar av ailab le for com m er cial use. The lef t - m ost ( high - or der) bit s in dicat e t he n et w or k class. Table 3 5- 1 pr ov ides r ef er ence inf orm at ion abou t t h e fiv e I P ad dr ess classes. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Tab le 3 5 - 1 . Re fe r en ce I nf or m at ion About t h e Fi ve I P Addr e ss Cla sse s Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all nov ice t o ex pert . IP H ig hN um b er of Ad dre ss Or de r New chapt er s include cov erag e of im por t ant t opics like VoI P Bit ands EAP Cla ss Form at Purp ose Bit ( s) Ad dre ss Ra nge N e t w ork / H ost Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age A N. H.H. H [ 1] Few larg e 0 1. 0. 0 .0 t o 7/ 2 4 or ganizat ion s 12 6. 0. 0. 0 Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

lev els, f rom

Ma x . H ost s 16 ,7 77, 2 14 [ 2] ( 2 2)

B N. N.H. H Medium - size 1, 0 12 8. 1 t o 14 / 16 65 ,5 43( 2 16 - 2) I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat or ganizat ion s 19 1. 254 . 0. 0 enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing 8 - 2)ing t echnologies. MastHer t heRelat t er mively s, con cep1, t s, t echn19 ologies, in t oday ' s24 net C N. N.N. 1, 0 2. 0. 1. 0ant od devices 22 /used 8 5(w2ork indu st ry . Lear n how t o incor g t255 echn olog0ies in t o a LAN/ WAN env ir onm ent . sm allpor at e int er net w or kin 22 3. . 254. Com plet e w it h new an d or u pdat ed ion chapt ganizat s er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all D w or kin g — Murltegar icastdless of1,ex 1,pert 1 ,0 ise. 22 4. 0. 0. 0 t o Not for — net p rof essionals, gr oup s ( RFC 23 9. 255 . 255. 2 55 com mer cial use 11 12) Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on E — Ex per iment al 1, 1, 1 ,1 24 0. 0. 0 t o — — a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions 25 4. 255 . 255. 2 55 t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich [ 1] N = Netw or k number, H = Host number pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu[ 2] ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient On e address is reser ved for t he broadcast addr ess, and one addr ess is r eserv ed for the netw ork . decisions for t h eir net w ork s. Figur e 35 - 4 illust r at es t he for m at of t h e com m ercial I P addr ess classes. ( Not e t he hig h- or der bit s in each class. )

Figu r e 3 5 -4 . I P Addr e ss For m at s A, B, an d C Ar e Av ai la ble f or Com m er ci Use [ View full size im age]

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The class of add ress can b e det erm ined easily by ex am ining t he fir st oct et of t he addr ess and m app The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t hat v alue t o a class ran ge in t he f ollowin g t able. I n an I P ad dr ess of 1 72. 31 .1 . 2, f or exam ple, t h e f essent ial an d cu t t ing- edg e t ech nologies. oct et is 17 2. Because 17 2 f alls bet w een 12 8 an d 1 91, 172 .3 1. 1. 2 is a Class B addr ess. Figur e 35 - 5 sum m arizes t h e r ange of p ossible v alues for t he f irst oct et of each add ress class. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Figu r echapt 3 5 -5 A Rancov geerag of ePossibl Vat opics lu es like Ex ist f or EAP t h e Fir st O ct et of Ea c New er s. include of im poret ant VoI s P and Ad dr ess Cla ss Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IP Subnet Addressing I P n et w or k s can b e div ided in t o sm aller n et w or k s called su bnet w or k s ( or subn et s) . Subn et t in g pr ov ides t he n et wor k ad min ist r at or w it h sev er al benefit s, includ ing ex t r a f lex ibilit y , m ore ef ficien t u of resses, and st h e capabilit y t o con t ain b road cast t r aff ic ( a b road cast w ill not cr oss a • net w or k add Table of Content r• out er ) . I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Sub net s ar e und er local adm inist rat ion . As such, t he out side w or ld sees an or ganizat ion as a sing le By netCisco w or kSystems, and hasInc. no d et ailed kn ow ledg e of t he or gan izat ion's int ern al st r uct ur e. A g iven or kPress addr ess can b e br oken up int o m any subn et wor k s. For ex am ple, 17 2. 16. 1 .0 , Pub lishnet er: w Cisco 17 2.Pub 16.Dat 2 .0 17tem 2. 16. and 17 2. 16. 4. 0 ar e all sub net s w it hin net w ork 172 .1 6. 0. 0. ( All 0s in t he h o e: ,Sep ber 3. 1 1,02, 003 por t ionI SBN: of an addr ess sp ecifies t h e en t ire net w ork . ) 1- 58 705 -1 19 -2 Pages: 11 28

IP Subnet Mask A sub net ad dr ess is cr eat ed b y bor r owin g b it s fr om t h e host field an d d esign at ing t hem as t h e Subn field. e nu erion of of bort he rowbed s v ar ies is sp ecified by trhefeerence su bnetpmask . Figur e age 35 - 6ofsh ows h The u Th pdat ed mb edit estbit - selling all-an in-done net w ork ing rov ides cover bit s ar e b orr ow ed fr om t h e Host add ress field t o cr eat e t he Su bnet ad dr ess f ield . essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

Figu novr ice e 3t o5 ex -6pert . Bi. t s Ar e Bor r ow e d f r om t he H ost Addr ess Fie ld t o Cr e at e t h Subn et Addr e ss Fie ld New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Sub asks hemsam f orm at andurr ep resen at ionwtor echn ask ing I P add resses. The suw bnet syst net em s,m pr oviduse in g t a or e er ealist ic pict e of t he trealld nique et w or en vir onm ent s in hichmask how er , h as oper binaraty e.1 sTools in alland bit sgu specif yin g f tor heopt Net ork and et wfor orm k ance f ields,w an d b inar y 0s in al pr of ev essionals id elines imwizing systSubn em per ill incr ease bit s spctecify field. Figur e help 35 - 7ing illust es a sam ple mor sub net ask. , cost - eff icient pr odu iv it ying an tdhe imHost pr ov e eff iciency, t her at r eader m ake e in tmelligent decisions for t h eir net w ork s.

Figu r e 3 5 -7 . A Sam pl e Su bn et M ask Consist s of All Bi na r y 1 s a n d 0 s

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Sub net m ask bit s shou ld com e f rom t he hig h- or der ( left - m ost ) bit s of t he host f ield, as Figur e 35 - 8 Pub lish er: Cisco Press illust rat es. Det ails of Class B and C su bnet m ask t y pes f ollow . Class A add resses ar e n ot discussed i Dat e: tem ber 1 1, 2 003gener ally are su bnet t ed on an 8 - bit b ound ary . t hisPub ch apt erSep because t hey I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 3 5 -8 . Subn et M a sk Bit s Com e f r om t he Hi gh -O r de r Bi t s of t he H os Fie ld The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Var ious et emeff asks ex ist help for Class B and C subn et s.mor e in t elligent , cost - eff icient pr odu ct ivt yitpes y anofd subn im pr ov iciency, ing t he r eader m ake decisions for t h eir net w ork s. The d ef ault su bnet mask f or a Class B add ress t hat has no sub net t ing is 25 5. 255 . 0. 0, w hile t h e sub m ask for a Class B ad dr ess 1 71. 16 . 0. 0 t hat sp ecifies 8 bit s of sub net t ing is 255 . 255 .2 55. 0. The r eas for t his is t h at 8 bit s of su bnet t ing , or 2 8 – 2 ( 1 for t he n et w or k ad dr ess an d 1 f or t he b r oadcast add ress) = 2 54 subn et s possible, w it h 2 8 – 2 = 2 54 host s p er su bnet . The su bnet m ask f or a Class C add r ess 19 2. 16 8. 2. 0 t hat sp ecifies 5 bit s of sub net t ing is

25 5. 255 . 255. 2 48. Wit h 5 b it s available f or subn et t ing, 2 5 – 2 = 3 1 su bnet s p ossible, w it h 2 3 – 2 = 6 host s p er su bnet . The r efer ence ch ar t s show n in Table 3 5- 2 an d Table 3 5- 3 can be u sed w hen plannin g Class B and C net w or ks t o d et er m in e t he requ ir ed num ber of sub net s and host s, an d t he app rop riat e su bnet mask

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Tab le 3 5 - 2 . Cla ss B Sub ne t t i ng Re f er e nce Ch ar t

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

N um b er of Bit s

Su bne t M ask

N um b er of Sub ne t s

N um b er of H ost s

2

25 5. 255 . 192. 0

2

16 ,3 82

25 5. 255 . 224. 0

6

81 90

25 5. 255 . 240. 0

14

40 94

5

25 5. 255 . 248. 0

30

20 46

6

25 5. 255 . 252. 0

62

10 22

3

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

4

Pages: 11 28

7 25 5. 255 . 254. 0 12 6 51 0 The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent 8 ial an d cu t t ing- edg25 e t5. ech 255 nologies. . 255. 0 25 4 25 4 9

13

25 5. 255 . 255. 1 28 51 0 12 6 Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom 25 5. 255 . 255. 1 92 10 22 62 nov ice t o ex pert . 25 5. 255 . 255. 2 24 20 46 30 New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP 25 5. 255 . 255. 2 40 40 94 14 Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age 25 5. 255 . 255. 2 48 81 90 6

14

Aut h ored by Cisco Sy ems, or ldw ide16 leader 25st5. 255 .w 255. 2 52 ,3 82 in net w or king f or t he I n t er 2 n et .

10 11 12

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new Tab an d ule pdat s onCsecur it y , st opte ical net w or k inag,r tscalabilit y, 3 5ed- 3chapt . Claerss Su bne t tor inage, g Ref r en ce Ch and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. N um b er of Bit s Su bne t M ask N um b er of Sub ne t s N um b er of H ost s Reader s w ill obt ain a g reat st an1 ding 2 25er 5. un 255der . 255. 92 2of LAN and WAN n et w or k ing, p ar 62t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a3b r oad r ang e of int egr al 25 sy5. st 255 em s. 255. and 2serv 24 ices, 6 in clud ing det ailed descr ipt ion 30s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . 4 erag e is also ext end ed25n5. . 255. 2 40 n14 Cov ot255 only t o new et wor k ing concep t s, but also t o 14 old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir 5 25 5. 255 . 255. 2 48 30 6 onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease 255 . 255. 2 52 2 , cost - eff icient pr6 odu ct iv it y an d im pr ov e25 eff5. iciency, help ing 62 t he r eader m ake mor e in t elligent decisions for t h eir net w ork s.

How Subnet Masks Are Used to Determine the Network Number The r ou t er perf or ms a set pr ocess t o det er min e t he n et w or k ( or , m or e specif ically , t h e su bnet w or k)

add ress. Fir st , t h e r out er ext r act s t h e I P dest inat ion addr ess fr om t h e incom in g packet and ret r ieve t he in t ern al subn et m ask . I t t hen perf or ms a logical AND oper at ion t o obt ain t he net w ork num ber . T causes t he h ost por t ion of t he I P dest in at ion ad dr ess t o be r em oved, wh ile t he d est inat ion net w or k nu mb er rem ains. The rou t er t hen look s u p t he dest inat ion net w or k num ber an d mat ches it w it h an out g oing int erf ace. Finally , it for w ard s t he fr am e t o t h e dest inat ion I P add ress. Specif ics r egar ding t logical AND operat ion ar e discussed in t he f ollow ing sect ion . •

•Logical

Table of Content s

AND Operation I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

ThrCisco ee basic r ules gov er n By Systems, Inc.

using a log ical AND on t w o b inar y num b er s. First , 1 " ANDed" w it h 1 y ield s Secon d, 1 " ANDed" w it h 0 y ield s 0. Finally , 0 " ANDed" w it h 0 y ields 0 . The t ru t h t able pr ov ided in Table 3 5- 4 illust r at es t he ru les f or logical AND operat ion s. Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Tab le 3 5 - 4 . Ru le s for Logical AND O per a t i ons I np ut

I np ut

Out put

1 u pdat ed edit ion of t he b est - selling 1 1 p rov ides cover age of The all- in- one net w ork ing r ef erence essent ial an d cu t t ing- edg e t ech nologies. 1 0 0 0 0

1 0 Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . 0 0 New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Tw o sim gueidelin ex ist for trem er ingliklogical AND ion s: Usin g age a logical AND on a 1 wi Covple erag of cutest ing edge echnemb ologies e opt ical n etoperat wor k ing and st or 1 yields t h e or iginal v alue, and u sing a logical AND on a 0 w it h any num ber y ield s 0. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Figur e 35 - 9 illust r at es t hat w hen a logical AND of t he d est inat ion I P ad dr ess an d t he subn et m ask is per for m edor , kt hinegsu bnetnologies w or k nuHand mb erbook rem ,ains, he ,r out u ses t o for w ar refer d t heence packt et . I n t ern et w Tech Fourw t hhich Ed ittion is aercom pr ehensive hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Figu e it3h 5new -9 .an Apply ined g chapt a Logical ANDit yt, ost or t he Dopt estical i nanet t iw on e ss—t he Com plet er w d u pdat er s on secur age, or kIinPg,Addr scalabilit y, Subn et M a eskanPr Su bn wtor umare b eressen t ial t o all and speed, t h is book is a com plet d uod p- t uce o- d atse trh efe er ence t oet t he op k icsNt hat net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Address Resolution Protocol Overview For t w o m achines on a given net w or k t o com m unicat e, t hey m ust kn ow t h e ot her m achine's ph ysical ( or MAC) ad dr esses. By br oadcast in g Ad dr ess Resolut ion Pr ot ocols ( ARPs) , a host can dy nam ically discov er t he MAC- layer ad dr ess cor r espon ding t o a par t icular I P n et w or k lay er •add ress. Table of Content s •

I ndex

IAft nt eer rn et w or k ing s H aad ndbook , Four Edit ion cr eat e an ARP cache t o st ore t he r ecent ly r eceiv ing Te a chnologie MAC- layer dr ess, I Pthd ev ices acquir ed I Pt oMAC ad dr ess m ap ping, t hus avoidin g h avin g t o br oadcast ARPs w hen t hey w ant By Cisco Systems, Inc. t o recont act a dev ice. I f t he device does not r esp ond w it h in a specif ied t im e fr am e, t he cache ent r y is f lu sh ed . Pub lish er: Cisco Press

Pub Dat e: Sep tem ber erse 1 1, 2 003 I n addit ion, t he Rev Add r ess Resolut ion Prot ocol ( RARP) is used t o m ap MAC- lay er addr esses I SBN: 158 705 -1 19 -2 w hich is t he logical inv erse of ARP, m ig ht be used by disk less t o I P addr esses. RARP, w or kstPages: at ions 11 28 t hat do n ot k now t heir I P ad dr esses wh en t h ey boot . RARP r elies on t h e pr esence of a RARP ser ver w it h t able ent r ies of m apping s fr om MAC lay er t o I P addr ess m apping s.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Internet Routing I nt er net r out in g d ev ices t rad it ionally hav e been called g at ew ay s. I n t oday 's t er m in ology , how ev er , t h e t erm gat ew ay r efer s specif ically t o a d ev ice t hat perf or m s applicat ion lay er pr ot ocol t r anslat ion bet w een devices. I n t er ior g at ew ay s r efer t o devices t hat per for m t h ese pr ot ocol •fu nct ions b et Table s or net w ork s u nder t h e sam e ad m in ist r at iv e cont r ol or au t hor it y , w eenofmContent achines •such as a corIpor ndexat ion' s int er nal net w or k . These ar e kn ow n as aut onom ous sy st ems. Ext er ior Igat nt eew rn et ws orper k ingfor Tem chnologie s H af un ndbook ay pr ot ocol ct ion, Four s betthwEdit eenion independ en t n et w or k s. By Cisco Systems, Inc.

Rou t er s w it h in t h e I nt ern et ar e or ganized hierar chically . Rout ers used f or inf orm at ion exchan ge w it hin aut on omou s syst em s ar e called in t erior r out er s, w hich use a v ar iet y of I n t er ior Gat ew ay Pub lish er: Cisco Press Pr ot ocols ( I GPs) t o accom plish t h is pur p ose. Th e Rout in g I nf or m at ion Pr ot ocol ( RI P) is an Pub Dat e: Sep tem ber 1 1, 2 003 exam ple of an I GP. I SBN: 1- 58 705 -1 19 -2

Rou t erPages: s t h at11m 28ov e inf orm at ion bet w een aut onom ous sy st em s ar e called ext er ior r out er s. These r out er s use an Ex t erior Gat eway Prot ocol t o exchan ge inf or mat ion b et w een au t onom ous syst em s. The Bor der Gat ew ay Pr ot ocol ( BGP) is an exam ple of an Ex t er ior Gat ew ay Pr ot ocol.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

NO TE

Specific out p rot BGP tand e kad dr essed in indiv erfsrom Con cise rov ering v iew s ofocols, t echnincluding olog ies essen ial t oRInP, et ar wor ing pr ofession als idual at all ch levapt els, pr esent ed in Par t VI I , lat er in t his b ook. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing IP Routing

edge t echn ologies lik e opt ical n et wor k ing and st or age

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I P r out in g p rot ocols ar e d yn amic. Dy nam ic r out in g calls f or r out es t o b e calcu lat ed aut om at ically at erv b ynologies sof t w arHand e in rbook ou t in,gFour devices. w it h st at ic rrefer ou t ing, w hich I n t regu ern etlar w orint k in g als Tech t h Ed This it ion ,cont is ar ast coms pr ehensive enceint hat renables out er s ar ew est by t h e net twoorun k derst adm inist at or and do en not ch ange unt he er net ww orork k ing net orab kinlished g p r ofessionals and ran d im plem t cont em por arilyt int net adm inist r at or Mast chang t hem . s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t echnologies. erest he t er m indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . An r out ing le, an w hdich consist s of dest ion ad pairnet s, w isorused enable y, ComI P plet ew it ht ab new u pdat ed chapt er s in onatsecur it dr y , ess/ st ornex age,t - hop opt ical k in g,t oscalabilit dy nam ic r out in g. An ent r y in t his t able, f or exam ple, w ould be in t erp ret ed as follow s: Tot ial gett ot oall and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen net w or k 17 2. 31. 0. 0 , sen d t h e pack et out Et h er net int erf ace 0 ( E0) . net w or kin g p rof essionals, r egar dless of ex pert ise. IReader P r out in specifies t hat I P er datun agr ams avel of t h rou int er net w ork e hop a tlar imlye. t h The sg w ill obt ain a g reat der st ant rding LANghand WAN n et wsoron k ing, p aratt icu e ent ir e rhar outdw e is now n at and t he ser on set of inv t heolv j our how ev eral . I tnst , at each st op, t h is e nex ar ne,otprkot ocols, v ices edney, . Fu ndam ent echead nology inf or mat ion pr ovt ided on dest inat ion edalby at ching e dest inat wit h in t he ipt dat ags,r am it h quest an ent ry a b r oad r angisecalculat of int egr sy m st em s andt hserv ices, inion cludaddr ing ess det ailed descr ion revw iew ions in hesucur en t cept n ode's r our eh t in en g tsion able.and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . t o ten re rcon comp Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Each node' inv olvem enor t in he rou ing ur preocess is reallim it w edortld o for s based syst em s, prsovid in g a m e rtealist ic tpict of t he n etwwar ording k ing pack en viretonm ent s on in w hich int er nal in for m at ion. The nodes do not m onit or w het her t he pack et s get t o t heir f in dest inat ion, pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill al incr ease nor does I P pr ov ide f or er r or r epor t ing back t o t he sour ce w hen rou t ing anom alies occur . Th pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient is tdecisions ask is leftfor t o tan ot her I nt ers. net pr ot ocol, t h e I nt ern et Con t r ol Message Prot ocol ( I CMP) , w hich is h eir net w ork discussed in t he f ollow ing sect ion.

Internet Control Message Protocol The I n t er net Cont r ol Message Pr ot ocol ( I CMP) is a net w ork lay er I nt er net p rot ocol t hat pr ovides m essage p ack et s t o repor t err or s and ot h er in for m at ion r egar ding I P p acket p r ocessin g b ack t o t he sou rce. I CMP is docum ent ed in RFC 79 2. •

Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

ICMP Messages By Cisco Systems, Inc.

I CMPs g en er at e sev er al k inds of usef ul m essag es, in clud ing dest in at ion u nr each able, echo Pub lishand er: Cisco Press r eq uest r eply, r ed ir ect , t im e exceed ed , and r out er adv er t isem en t an d r ou t er solicit at ion Pub Dat e: Sep tem 1 1,m 2 003 m essages. I f an I ber CMP essage can not be deliver ed , no second one is generat ed . This is t o avoid I SBN: 158 705 -1 19 -2 an en dless flood of I CMP m essag es. Pages: 11 28

When an I CMP d est inat ion u nr eachab le message is sen t b y a r out er , it m ean s t hat t he r out er is incapab le of send in g t he pack age t o it s f in al dest inat ion. The r out er t h en discard s t he origin al pack et . Tw o r eason s exist f or w hy a dest inat ion mig ht be un reachable. Most comm only , t h e sour ce host h as specif ied a n onexist ent addr ess. Less f r eq uent ly , t he rou t er does not hav e a r out e t o t he dest in at ion. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ialion an dunr cueach t t ingedgm e essages t ech nologies. Dest inat able includ e fou r basic t y pes: net w or k un reachable, host un reachable, p rot ocol u nr each able, and por t unr each able. Net w or k u nr eachab le m essages usually m ean t hat a failur e h as occu rr ed in r out in g or addr essing a packet . Host unr eachable Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom m essages usually ind icat e deliv ery failur e, such as a w r ong subnet m ask . Pr ot ocol un r eachab le nov ice t o ex pert . m essages gener ally m ean t hat t he dest in at ion d oes not su ppor t t he up per - lay er pr ot ocol specifNew ied inchapt t he p et . Por tcov u nrerag each essages im plylike t hat t he TCPEAP sock et or por t is not erack s include e able of immpor t ant t opics VoI P and av ailab le. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age An I CMP echo requ est m essage, w hich is generat ed by t he pi ng com m and, is sent by any host t o t est nod r eachab y acr oss an int et wor . The I in CMP replyf orm tessag Auteh ored by ilit Cisco Sy st ems, wern or ldw idekleader netecho w or king he I n et erindicat n et . es t hat t he nod e can b e successf ully r each ed . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat An I CMPnet r edir ect is sent tby t h derst e rouand t er tan o tdheimsour ceenhost t o em st imu m ore efw ficien t enables w or kinmg essage p r ofessionals o un plem t cont por lat ar ye int er net ork ing rt echnologies. out ing . The r ou t er st ill f or w ard s t he or iginal pack et t o t he dest inat ion. I CMP r edir ect s allow h ost Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing rindu out ing t ab les t o r em ain small b ecau se it is necessary t o k now t he ad dr ess of only on e r out er st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent, . even if t hat t er does not pred ov ide t heerbest h . it Ev er r eceiving an wI CMP edscalabilit ir ect Com plet e w itrou h new an d u pdat chapt s on pat secur y ,enst af ortage, opt ical net or k inrg, y, m essage, som e dev ices m ight cont inu e using t he lesseff icient r out e. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. An I CMP t im e- exceed ed m essage is sent by t he r out er if an I P pack et 's Tim e- t o- Liv e field (Reader exp r essed hops eaches zer o.ofThe e- tWAN o- Liv n e et f ield event s tpacket s ftrom s w illinobt ain or a gsecond reat er s) unrder st an ding LANTim and w or pr k ing, p ar icu lar ly he cont inuarously cirocols, culat ing ern et w olv or ked if . t he in t ernent et w k cont ain s inf a ror out in gion loop r out on er har dw e, pr ot andt he serinv tices inv Fu ndam alort ech nology mat is .prThe ov ided tahen discard or iginal pack et .s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions b r oad r angset he of int egr al sy st em t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s,Router-Discovery pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich ICMP Protocol pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient I CMP Rout er - Discov er y Pr ot ocol ( I DRP) uses rou t er adv er t isem ent and r out er solicit at ion decisions for t h eir net w ork s. m essages t o discov er t he addr esses of r out er s on direct ly at t ached su bnet s. Each r out er per iodically m ult icast s r out er adv er t isem en t m essag es f r om each of it s int er faces. Host s t hen discover ad dr esses of rou t er s on d ir ect ly at t ached sub net s by list ening f or t hese m essages. Host s can use rou t er solicit at ion messages t o r equest im m ediat e adv ert isem en t s r at her t h an w ait ing for unsolicit ed m essages.

I RDP off er s sever al ad van t ages ov er ot her m et h ods of d iscover ing add resses of n eigh bor ing r out er s. Prim ar ily , it does not r eq uir e host s t o r ecogn ize rou t ing pr ot ocols, nor does it r eq uire m anual con figu r at ion b y an adm inist rat or . Rou t er adv er t isem ent m essages enable h ost s t o d iscov er t he exist ence of neighb orin g r ou t er s, bu t n ot w hich rou t er is best t o r each a p art icular d est inat ion . I f a host uses a p oor fir st - hop r out er t o reach a par t icular d est inat ion , it r eceiv es a r ed irect m essag e ident ify ing a bet t er choice. •

Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Transmission Control Protocol The Tr an sm ission Con t rol Pr ot ocol ( TCP) pr ovid es r eliable t r ansm ission of d at a in an I P env iron ment . TCP cor r esp onds t o t he t ran sp or t lay er ( Lay er 4) of t he OSI refer ence m odel. Am ong t he ser vices t hat TCP pr ovides ar e st r eam dat a t r ansfer , r eliabilit y , eff icient flow cont r ol, •fu ll- dup lex op Table Content er at of ion, and smu lt iplex ing . •

I ndex

IWit nt eh rn st et w or k ing Tea chnologie a ndbook , Four ream d at t r an sf ers ,H TCP d eliv er sthanEdit union st ru ct u r ed st r eam of by t es id en t ified b y seq uence nu mb er s. Th is ser vice benef it s applicat ions b ecause t h ey d o n ot h ave t o chop dat a int o b lock s By Cisco Systems, Inc. befor e h andin g it off t o TCP. I nst ead, TCP g rou ps b yt es int o seg m en t s and passes t hem t o I P for deliver y. Pub lish er: Cisco Press

temilit bery 1by 1, 2pr 003 TCPPub offDat er se:r Sep eliab ov iding connect ion- or ien t ed , end- t o- en d r eliable pack et deliver y I SBN: 158 705 -1 19 -2 t hr ou gh an in t er net w or k . I t d oes t his by sequencing by t es w it h a f orw ar din g ack now ledgm ent nu mb er Pages: t hat11indicat 28 es t o t h e dest inat ion t he n ex t by t e t hat t he sou rce ex pect s t o r eceiv e. By t es not ackn ow ledg ed w it hin a specified t im e p er iod ar e r et r ansm it t ed. Th e r eliabilit y m ech anism of TCP allow s devices t o d eal wit h lost , delay ed , du plicat e, or misr ead p ack et s. A t im eout m ech anism allow s d ev ices t o det ect lost p ack et s and r equest r et r ansm ission.

TCP off er s ef ficient flow con t r ol, w hich m eans t h at , w hen sen ding ackn owledg ment s back t o t he The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of sour ce, t he r eceivin g TCP pr ocess in dicat es t he h ig hest seq uence nu mb er t hat it can receiv e essent ial an d cu t t ing- edg e t ech nologies. w it hout ov er f lowin g it s in t er n al bu ffer s. Full- dup opov erer atvion t hatolog TCP ocesses h send r eceiveals at at t he e t imf rom e. Conlex cise iewm s ean of t sechn iespressen t ial can t o nbot et wor k ing and pr ofession allsam lev els, nov ice t o ex pert . Finally, TCP's m u lt ip lex ing m ean s t hat nu mer ous sim ult aneous u pper - layer conv er sat ion s can b e m ult iplexed ov ereras single ion. New chapt includeconn cov ect erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

TCP Connection Establishment

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

To u seetreliable anspor t ser v ices, s mt hust ablish connect ion- or ien t edence session I n t ern w or k in gt rTech nologies HandTCP bookhost , Four Edest it ion , is aa com pr ehensive refer t hatw it h one an ot her . Con nect ion est ablish ment is per for m ed b y using a t h reew ay han dshak e enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing m ech anism . Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t echnologies. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . At hr ee- w ay hand sh ake sy nchr onizes bot h end s of a conn ect ion by allow ing bot h sides t o ag ree Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, up on in it ial sequ en ce num ber s. This m ech anism also gu aran t ees t h at b ot h sides ar e r eady t o and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all t r ansm it dat a and k now t hat t he ot h er side is ready t o t r ansm it as well. This is n ecessar y so t hat net w or kin g p rof essionals, r egar dless of ex pert ise. pack et s are not t ran sm it t ed or r et ran sm it t ed dur ing session est ablishm ent or aft er session tReader er min at s ion w ill. obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Each host r an dom ly ch ooses a seq uence num ber u sed t o t rack b yt es w it hin t h e st ream t h at it is a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions sen ding and r eceivin g. Th en , t he t hr ee- w ay han dshak e pr oceeds in t h e follow ing m anner : t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy The f ir st host ( Host A) in it iat es a connect ion b y sen ding a p ack et w it h t he in it ial seq uence syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich nu mb er ( X) an d SYN bit set t o ind icat e a connect ion r equ est . Th e second host ( Host B) receiv es pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease t he SYN, r ecor ds t h e seq uence num ber X, and r ep lies by ack now ledging t h e SYN ( w it h an ACK = pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient X + 1) . Host B includ es it s own init ial sequ en ce n um ber ( SEQ = Y) . An ACK of 2 0 m eans t hat t he decisions for t h eir net w ork s. host has r eceiv ed by t es 0 t hr oug h 1 9, an d ex pect s by t e 20 n ex t . Th is t ech nique is called f or w ard ackn ow ledg m en t . Host A t hen ack now ledges all b yt es t h at Host B sen t w it h a for w ard ackn ow ledg m en t ind icat ing t h e nex t by t e Host A exp ect s t o r eceive ( ACK = Y + 1) . D at a t r ansf er t hen can b eg in.

Positive Acknowledgment and Retransmission A sim ple t r anspor t pr ot ocol m ight imp lem ent a r eliab ilit y an d flow cont r ol t echn iq ue in w hich t he sour ce send s one p ack et , st ar t s a t imer , and w ait s f or an ack now ledg ment befor e sendin g a new pack et . I f t he ack now led gm en t is n ot r eceiv ed bef ore t he t im er ex pir es, t he sour ce r et ran sm it s t he packet . Su ch a t ech nique is called posit iv e ackn ow ledgm ent and ret r ansm ission ( PAR) . •By assig ning Table eachofp Content ack et as sequ en ce num ber , PAR en ables host s t o t r ack lost or du plicat e •pack et s cau sed I ndex by n et wor k d elay s t h at r esu lt in pr em at u re ret r ansm ission. Th e seq uence Inu nt mb e rn et Te chnologie a ndbook Four Edit erwsorark ing e sent back ins tHhe ackn ,ow ledthgm enion t s so t h at t h e ackn owledg ment s can b e t r ack ed. By Cisco Systems, Inc.

PAR is an in ef ficien t u se of bandw id t h, h owev er , becau se a host mu st w ait f or an ackn ow ledg m en t bef ore send in g a new p ack et , an d on ly one pack et can be sent at a t im e. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 TCP Pages: Sliding Window 11 28

A TCP sliding w indow pr ovid es m or e eff icient use of net w or k band w idt h t han PAR becau se it enables host s t o sen d mu lt ip le by t es or pack et s befor e w ait ing for an ack now ledgm ent . I n TCP, t h e receiv er specif ies t he cur r en t w ind ow size in ev er y p ack et . Becau se TCP p r ovides a The pdat ed conn edit ion of t he b est - selling allnet winork p rov idesa cover by t e-ust ream ect ion, w in dow sizes ar e inexpone ressed bying t es.r ef Therence is m ean s t hat w ind age ow isoft he essent ial an d cu t t ingedg e t ech nologies. nu mb er of dat a by t es t hat t he sender is allow ed t o sen d b ef or e w ait in g for an ackn ow led gm en t . I nit ial w ind ow siz es ar e ind icat ed at con nect ion set up but m ight v ary t hr ough out t he dat a t r ansfer t o pr ov ide flow con t r ol. A w ind ow size of zer o, f or inst ance, m eans " Send no dat a. " Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice o gexwpert . oper at ion, f or exam ple, t h e send er mig ht hav e a sequence of by t es t o I n a TCP slidtin indow sen d ( num ber ed 1 t o 10) t o a r eceiver w ho has a w indow size of 5 . The sender t hen w ou ld place New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP a w in dow ar oun d t he fir st 5 b yt es an d t r an sm it t hem t oget her . I t wou ld t h en w ait for an ackn ow ledg m en t . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age The r eceiv er w ould respond w it h an ACK of 6 , indicat ing t hat it h as r eceived by t es 1 t o 5 and is Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . exp ect ing by t e 6 n ex t . I n t he sam e pack et , t he receiv er w ould indicat e t hat it s w ind ow siz e is 5. The send w ou ld m ov e tHand he sliding indow 5 by t es, tiso at hcom e r igpr htehensive and t r ansm it ence by t est hat 6 t o 1 0. I n t ern et wer or tkhen in g Tech nologies book ,wFour t h Ed it ion refer The r eceiv er w ould respond w it h an ACK of 1 1, ind icat in g t h at it is exp ect ing seq uenced b yting e 11 enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork nex t . I n t his pack et , t he receiv er m ig ht indicat e t hat it s w ind ow siz e is 0 ( becau se, f or exam le, t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ping it s int er nal buf fer s ar e full) . At t h is point , t he sen der cannot sen d an y m or e by t es unt il t he indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . rCom eceiver anot her eted w itchapt h a wer ind ow secur size gr han 0. plet esends w it h new an dpuack pdat s on it yeat , sterortage, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

TCP Packet Format

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Figur e 35 - 10 illust r at es t he field s and ov er all f or mat of a TCP pack et . a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Figu r e 3 5 -1 0 . Tw e lv e Fi el ds Com p r ise a TCP Pa ck et pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

TCP Packet The u pdat ed editField ion of tDescriptions he b est - selling all- in- one

net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The f ollow in g d escr ipt ions sum m ar ize t he TCP pack et f ields illust r at ed in Figur e 35 - 10: Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Sou nov ice rcet oport ex pert a nd . de st i na t ion por t — I d en t ifies point s at w hich upp er - lay er sou r ce an d dest inat ion pr ocesses receiv e TCP ser v ices. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Se que nce nu m ber — Usually specif ies t he nu m ber assign ed t o t he f ir st by t e of dat a in t he Cov e essage. of cut t ing t echn e opt ical et wor k ting or age cur rerag en t m I n edge t he con nectologies ion - estlik ablishm ent nphase, his and f ieldstalso can be used t o ident if y an in it ial seq uence num b er t o be used in an u pcom in g t ran smission . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Ack now le dg m e nt num be r— Cont ains t he sequence n um ber of t he n ex t by t e of dat a t hat I n t ernt he et wsend or k inerg Tech nologies book t h Ed it ion , is a com pr ehensive refer ence t hat of t he pack et Hand exp ect s t o, rFour eceive. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. t eres m s, t s, of t echn anin d devices in .t oday ' s net w ork ing D a t a offMast se t —erI nt he dicat t hecon nucep m ber 32-ologies, bit w or ds t h e TCP used h ead er indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet Re ser e w ve it hd— newRemain an d u pdat s reserv ed chapt ed f orerfsuton ur esecur u se.it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Fla gs— Car ries a varriet y of contof r olexinf orm at ion , including t h e SYN and ACK bit s u sed for net w or kin g p rof essionals, egar dless pert ise. connect ion est ablishm ent , an d t he FI N bit used f or connect ion t er m inat ion. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e owot— Specif ies ser t h ev ices siz e inv of olv t heed sender 's r eceiv indow ( t hat t heion b uffiserprsp har dwWarind e, pr ocols, and . Fu ndam ent ale twech nology inf is, or mat ovace ided on av ailab forint inegr comaling dat a)s. and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions a b r oad r angle e of sy st em t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Chee ck dicat et her he h ead er wk as aged t r ansit Cov erag is sum also — extI n end ed es n otwhonly t o tnew n et wor ingdam concep t s,inbut also. t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich U rge nt poin t er Poin tand s t o gu t he f irst urfgent by t esyst in tem he pack etm . ance w ill incr ease pr of essionals oper at e.—Tools id elines or optdat imaizing per for pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Opt ions— Specif ies v ar ious TCP opt ions. decisions for t h eir net w ork s. D a t a— Cont ains upp er - lay er in for m at ion.

User Datagram Protocol The User Dat agr am Pr ot ocol ( UDP) is a connect ionless t ran sp ort lay er pr ot ocol ( Lay er 4) t hat belongs t o t h e I nt er net pr ot ocol f am ily . UDP is basically an int er face bet w een I P an d u pper - layer pr ocesses. UDP pr ot ocol por t s dist in guish m ult iple app licat ions r u nning on a sing le device f rom •one an ot her . Table of Content s •

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IUnlike nt e rn ettwhe or kTCP, ing TeUDP chnologie a ndbook , Four Edit cont ion r ol, add s Hno reliabilit y, thflow

or er r or - recover y f unct ions t o I P. Becau se of UDP's sim plicit y, UDP header s cont ain few er by t es and con su m e less net w or k ov er h ead t han By Cisco Systems, Inc. TCP. Pub lish er: Cisco Press UDP is u sef ul in sit uat ions in w hich t he r eliab ilit y m echanism s of TCP ar e n ot n ecessar y , such as Pub Datwe:her Sepetem ber 1, 2 003 in cases ah ig1herlay er pr ot ocol m igh t pr ov ide er ror and flow cont rol. I SBN: 1- 58 705 -1 19 -2

UDP isPages: t h e t11 r anspor t pr ot ocol for sev er al w ell- kn ow n ap plicat ion lay er pr ot ocols, in clud ing 28 Net w ork File Sy st em ( NFS) , Sim ple Net w or k Manag em ent Pr ot ocol ( SNMP) , D omain Nam e Sy st em ( DNS) , and Tr ivial File Tr ansfer Pr ot ocol ( TFTP) . The UDP pack et for m at cont ain s fou r fields, as show n in Figur e 35 - 11. Th ese includ e Sour ce Port , Dest inat ion Port , Leng t h, an d Check sum f ield s. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r es 3of5 t-1 1 . olog A UDP Patck Fourals Fiat el all dslev els, f rom Con cise ov er v iew echn ies essen ial e t ot nConsist et wor k ingsprof ofession nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. The Sou r ce an d Dest inat ion p ort fields cont ain t he 16- b it UDP p r ot ocol por t n um ber s used t o Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e dem ult iplex dat ag ram s f or r eceiv in g ap plicat ion lay er pr ocesses. A Lengt h f ield specif ies t he har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on lengt h of t he UDP header an d d at a. The Checksum field pr ov ides an ( opt ional) int egr it y check on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t he UDP header and d at a. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Internet Protocols Application Layer Protocols The I n t er net pr ot ocol suit e includes m any applicat ion lay er pr ot ocols t hat r ep resen t a w ide v ariet y of ap plicat ion s, in clu ding t he f ollowin g: • •

Table of Content s

Fil e t raInsfe ndex r prot ocol ( FTP) — Moves f iles b et ween devices

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Si m ple n et w or k m an ag em e nt p rot ocol ( SN M P) — Prim ar ily repor t s an om alou s net w or k condit ions and set s net w ork t hr eshold v alues

By Cisco Systems, Inc.

PubTe lishlne er: tCisco Press — Ser v es

as a t er m in al em ulat ion p r ot ocol

Pub Dat e: Sep tem ber 1 1, 2 003

XI SBN: w i ndow s— Ser 1- 58 705 -1 19 -2 v es as a d ist r ibut ed w indow ing an d g rap hics syst em used for com mu nicat ion b et w een X t erm inals an d UNI X w or k st at ion s Pages: 11 28 N e t w ork fil e syst e m ( N FS) , Ex t e rna l da t a r ep re se nt a t ion ( X D R) , and Re m ot e pr oce du re cal l ( RP C) — Work t oget her t o en able t r anspar ent access t o r em ot e net w or k r esour ces The uSi pdat m ple ed edit m a il iont r of antsf heerb p est rot - selling ocol ( allSMTP in- one ) — Prov net wides ork ing elect r ef r onic erence m ail p rov serv ides icescover age of essent ial an d cu t t ing- edg e t ech nologies. D om ai n n am e sy st e m ( D N S) — Tran slat es t h e nam es of net w or k nodes int o net w or k add resses Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Tablenov 3 5-ice 5 list t o sex t hpert ese . h ig her- lay er pr ot ocols and t he applicat ions t h at t h ey su ppor t . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Tab le 3 5 - 5 . Hig he r -Lay er Pr ot ocols a nd The ir Ap pli cat ion s

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

I nAp t ern pliet cawtor i on k in g Tech nologies Hand book , Four t h Prot Ed it ion ocols , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing File t ran sf er Mast er t he t er m s, con cep t s, t echn ologies, FTP t echnologies. an d devices used in t oday ' s net w ork ing indu ry . Lear how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Net st w ork mannagement SNMP Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Term inal em ion is a com plet e an d u p- t o- d atTelnet and speed, t huislat book e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Dist r ibut ed file ser v ices NFS, XDR, RPC, X Window s Reader sw and WAN n et w or k ing, p ar t icu lar ly t h e Elect ron icillmobt ail ain a g reat er un der st an ding of LAN SMTP har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on r ibut ed nam seral v ices DNS aDist b r oad r ang e of ing int egr sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary TCP/ I P defines t h e larg e suit e of pr ot ocols t hat ar e m ost w idely used t od ay. I P addr esses ar e used on t h e I nt er net t o deliv er dat a t o com pu t ers w or ldw ide. Th e pr ot ocol suit e includ es t r anspor t pr ot ocols su ch as TCP t h at pr ov ide conn ect ion- or ient ed guar ant eed deliv ery of d at a. •Ther e ar e also Table Content nonof- con nectsion - orient ed t r anspor t pr ot ocols su ch as UDP t hat pr ovid e best - ef for t •deliver y of dat I ndex a. The TCP/ I P pr ot ocol suit e also includ es ap plicat ion lay er pr ot ocols t hat are open Ist ntandar e rn et wdor ing Teopen chnologie s H a ndbook Four thofEdit s.k This st andar d and, ease in ion t er oper abilit y bet w een com put in g sy st em s is w h at has mad e TCP/ IInc. P t he m ost pop ular pr ot ocol u sed t oday . By Cisco Systems, Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

How ar e I nt er net p r ot ocols d ocu m en t ed ?

2:

I ndex ar e t he t w o pr im ar y responsibilit ies of I P? What

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

: Which By Cisco 3 Systems, Inc.field

in t h e I P pack et k eeps p acket s f rom looping endlessly in a m alcon figu red net w or k?

Pub lish er: Cisco Press

4:

How is an I P ad dr ess g en er ally r ep resent ed?

Pub Dat e: Sep tem ber 1 1, 2 003 I5 SBN: 58 705 : 1How is-1t19 h e-2class

of an I P ad dr ess d et er m ined?

Pages: 11 28

6:

What is t h e pur pose of t h e subn et m ask in an I P add r ess?

7:

What is t h e pur pose of Ad dr ess Resolut ion Pr ot ocol ( ARP) ?

8 : edWhat is t of h e t fun ctest ion- selling of I nt erallnetinCont ocol ( I pCMP) ? cover age of The u pdat edit ion he b oner ol netMessage w ork ing Pr r efoterence rov ides essent ial an d cu t t ing- edg e t ech nologies. 9 : What t y pe of d at a d eliv er y does TCP pr ov ide? Con 1 0 :cise How ov erd voes iewUser s of tDat echn agr olog amies Pr essen ot ocolt ial ( UDP) t o n et diff wor er kfring om pr Trofession ansm ission als atCon allt rol lev els, Protfocol rom nov ice (tTCP) o ex ? pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 36. IPv6 Obj e ct i ve • •

Table of Content s

Pr ovid e an over view of I Pv 6, t h e new est ver sion of t h e m ost pop ular pr ot ocol used t oday . I ndex

IOn nt eernof et w or kn ing chnologie a ndbook t he ewTe est m ajor sstH andar ds, Four on tth h eEdit horion izon

is I Pv 6. Alt houg h I Pv 6 has not of ficially becom By CiscoeSystems, a st andInc. ard , it is w or t h som e over v iew . I t is ver y possib le t hat t his inf or m at ion w ill chang e as w e m ov e closer t o I Pv 6 as a st an dar d, so y ou should use t h is as a g uide int o I Pv6 , not t he Pub definit e infPress orm at ion. lish er:ivCisco Pub Dat e: Sep tem ber 1 1, 2 003

A n um ber of book s ar e n ow being pub lish ed t hat cover in det ail t h is em er ging st andar d ; if y ou I SBN: 1- 58 705 -1 19 -2 ar e lookin g f or m or e det ails y ou shou ld r efer t o t hese book s. All t he RFCs av ailab le on t he Pages: 11 28 I nt er net h ave t he r aw det ails on how t his st and ard is dev elop ing. How ev er , t h ese d ocu ment s ar e dif ficult t o int er pr et at fir st glan ce an d requ ire som e com mit m ent t o g oing t hr oug h an y num b er of RFCs p er t ainin g t o m any sub ject s all r elat ed t o I Pv 6 developm ent . I nt er net Pr ot ocol Ver sion 4 is t he m ost p opular pr ot ocol in u se t oday ( see Ch apt er 35 , " I nt er net Pr ot ocols" , alt houg e -som e quallestinions abnet outwitork s capabilit y t o ser ve ides t he Icover nt er net The u pdat )ed edit ion hoft hter hee bar est selling one ing r ef erence p rov age of com mu nit y m uch longer . I Pv4 w as f inish ed in t he 1 970 s and has st ar t ed t o show it s age. Th e essent ial an d cu t t ing- edg e t ech nologies. m ain issue sur r ound ing I Pv 6 is add ressin g—or , t h e lack of ad dr essing—becau se m an y ex per t s believ e t h at w e ar e n ear ly out of t he f our b illion add resses av ailable in I Pv 4. Alt houg h t his seem s like aCon v er cise y lar ov geern vum iewber s ofoft echn add resses, olog iesmessen ult iple t iallart ogen et block wor sk ing ar e pr g iv ofession en t o gov alser atnm allen lev t ag els, enf cies rom and lar nov geice or gan t o ex izat pert ion. s. I Pv6 could be t h e solu t ion t o m any p rob lem s, bu t it is st ill not f ully dev elop ed and is not a st an dar d—y et ! New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Man y of t he f inest dev eloper s and engin eer ing m in ds h ave b een w ork ing on I Pv6 since t he ear ly Cov of of cutRFCs t ing edge echn ologies icaldet n etailed wor ksome ing and or ar age 19 90s. Huerag ndr e eds hav e tbeen w r it t en lik aned opt h ave majstor eas, in clu ding exp anded addr essing , simp lif ied h ead er f or m at , flow lab eling , aut h en t icat ion , and pr iv acy . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Ex pan ded ad dr essing m oves u s fr om 3 2- bit addr ess t o a 12 8- bit addr essing m et hod. I t also I n tov ern et wnew or k in Tech nologies Handcast book t h Ed itinion , is a comecim pr ehensive hat and pr ides erg unicast and b road ing, Four m et hods, ject s hexad al int o trefer he I Pence addrt ess, enables or kin g" .p" rtofessionals o un derster and an d im plem contt he emIpor intet er net w ork m oves f rnet omwusing o using " : " tas delimit s. Figur e 36 - 1 en sh tows Pv 6arpyack h ead er ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing for m at . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, pertPa ise.ck et H ea der For m a t Figur regar e 3dless 6 -1 .ofI ex Pv6 Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Description of IPv6 Packet Header The sim plified header is 40 bit s lon g an d t he f orm at consist s of Ver sion , Class, Flow Label, Pay load Len gt h, Nex t Head er , Hop Lim it , Sour ce Add ress, Dest in at ion Addr ess, D at a, and Pay load f ields. •

Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Hexadecimal "Hex" At it s sim plest , hex n um bers are base 16. Decim al is b ase 1 0, coun t ing fr om 0 t o 9, as we do in decimal, an d t hen adding a colum n t o mak e 1 0. Count ing in hex goes f rom 0 t o F b ef or e addin g a colum n. The char act ers A t hr oug h F r ep resen t t h e decim al values of 1 0 t h r ough 15 , as •illust rat ed in Table Figurofe Content 36 - 2. s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 3 6 -2 . H ex Cha r act e r s A Th r ough F Rep r esen t t h e Nu m ber s 1 0 Thr ou gh 1 5 Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Cou nt ing in hex goes as f ollow s: 0 1 2 3 4 5 6 7 8 9 A B C D E F 10 11 12 1 3 1 4 1 5 16 17 18 19 1A 1C 1D 1E 1F 0 2t he 1 an d up, as farallasinyou go. The1B u pdat ed edit ion2of b est - selling onew ant net wt oork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Addressing Description Let ' s look at an ex amp le of I Pv 6 add ress. The ad dr ess is an eight - p ar t hex ad dr ess separ at ed b y colons ( " : " ) . Each par t n can equal a 16 - bit num ber an d is eigh t p art s lon g, p rov iding a 128 - bit add ress lengt h ( 16 x 8 = 128 ) , •

Table of Content s

•Add resses ar Iendex n : n: n: n : n: n : n: n n = 4 digit hexad ecim al int eger , 16 x 8 = 128 add ress. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

1080:0:0:0:8:800:200C:417A Unicast address FF01:0:0:0:0:0:0:101Multicast address The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Broadcasting Methods I ncluded in I Pv 6 are a nu mb er of new br oadcast ing m et hods:

• •

Unicast Table of Content s I ndex

I nt e rn Mu et wlt oricast k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Any cast

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 Unicast I SBN: 1- 58 705 -1 19 -2

Pages: 11 28

Unicast is a com m unicat ion bet w een a single h ost and a sin gle r eceiver . Packet s sent t o a unicast add ress ar e deliver ed t o t he in t er f ace id en t ified b y t hat add ress, as seen in Figur e 36 - 3.

The u pdat ed edit b est - selling in- one netet w ork erence rov ides age of Figu r e ion 3 6of-3t he . Un icast Seallnds Pa ck s ting o ar efSpe ci fiped I nt ecover r f ace essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Multicast syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Mu lt icast isy com unicat ion w een help a sing and mmult ip lemor receiv Pack, et s are pr odu ct iv it an dmim pr ov e effbet iciency, ingle t host he r eader ake e in ers. t elligent cost - effsent icientt o all int er faces ident ified by t h at ad dr ess, as seen in Figur e 36 4. decisions for t h eir net w ork s.

Figu r e 3 6 -4 . M u lt ica st Sen ds Pack et s t o a Subn e t , a nd De f in ed De vi ce s Li st en f or M u lt ica st Pa ck et s

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Anycast Packet s sent t o an any cast add r ess or list of ad dr esses ar e deliv ered t o t he near est int er face Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom ident if ied by t hat ad dr ess. An ycast is a com m un icat ion bet w een a sin gle sen der and a list of nov ice t o ex pert . add resses, as show n in Figur e 36 - 5. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Figu r e 3 6 -5 . Any ca st Se n ds Pack e t s t o Specif ie d I n t er f a ce Li st a nd Ca n Aut h ored by Cisco Sy st ems,t awin or ldw leader kingt e f or Con Enide dN odesin anet ndw or Rou r st he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary Som e of t he b en ef it s of I Pv 6 seem obv ious: gr eat er add ressin g space, bu ilt - in QoS, and bet t er r out ing per for m ance and serv ices. How ev er , a num ber of b arr iers mu st be over com e b ef or e t he im plem ent at ion of I Pv 6. The biggest q uest ion f or m ost of us will b e w hat t he b usiness n eed is for •m ovin g f r om Table of Content cur r en t I Pv 4 st o I Pv6 . The k iller app has n ot app ear ed yet , b ut it m ay be closer t han •w e t hin k. TheI ndex secon d consider at ion is t he cost —it m ay not hav e m uch t o d o w it h har dw ar e Ir nt rn et w or k ing Te chnologie H a ger ndbook , Four Edit epelacem en t cost . All t h es lar r out ers thhav e ion upg r adable OSs I OS; t h e only necessit y is t he com mit Systems, m ent t o Inc. u pgr ading I OS. More lik ely t o d o w it h t r ain ing and supp ort of m in or I P d ev ices By Cisco such as pr int er s and net w or k fax es, t hey w ill suppor t t he n ew addr ess space. I Pv 6 has schem es t o su ppor t old an d n ew , how ev er , so t his may n ot ev en b e a b arr ier. The last issue t o con sid er is Pub lish er: Cisco Press t r aining : This w ill n eed t o h appen sooner or lat er because w e all need t o st ar t t h ink in g about Pub Dat e: Sep tem ber 1 1, 2 003 12 8- bit addr essing b ased on MAC addr esses in HEX. This in volv es all new w ay s of add ressin g I SBN: 1- 58 705 -1 19 -2 and w ill be an u ncomf or t able chang e for man y people. Pages: 11 28

This conclusion may seem negat iv e, bu t t h e gr eat er good w ill over pow er all t he up- f ron t issues. The issue is n ot w het h er y ou w ill hav e t o mov e t o I Pv6 , but w hen! We all n eed I Pv6 ; t h e incr eased addr ess sp ace, w hich is quad r upled, is n eeded for t he gr ow t h of I P ap pliances t hat we ar e st ar t in g t o h ear ab out w eek ly . I P- r eady car s ar e already sh ip ping t oday . Th is r eq uires m obilit y, wed hich ad dr in -I selling Pv6 . all- in- one net w ork ing r ef erence p rov ides cover age of The u pdat editision of essed t he b est essent ial an d cu t t ing- edg e t ech nologies. Of cour se, a nu m ber of ver y im por t ant feat ur es hav e n ot been discu ssed in t h is sect ion, includ in g QoS, m ob ile I P, au t oconfig ur at ion, an d secu r it y. All t hese areas ar e ex t rem ely im p ort an t , and un t il ICon Pv6cise is f inish , ysou ouldolog k eep rintgialt ot ot he ETFkWeb e f or t he r rent ov er ed v iew ofsh t echn iesr efer essen n etIwor ing prsit ofession alsmost at allculev els, f rom inf ormnov at ion. al new b ooks on I Pv 6 also ar e st ar t ing t o sh ow up on book st or e sh elv es and ice tSev o exer pert . should pr ov ide t h e deep er t echn ical det ail on addr ess headers and fu ll packet det ails. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What is t h e cu rr ent st andar d?

2:

I ndex is t h e main r eason f or I Pv6 being dev elop ed ? What

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Table of Content s

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3 : HowInc. m any By Cisco Systems, 4:

bit s does t h e new ex pand ed add ressin g p r ovide?

What ot her b en ef it s does ex pand ed add ressin g pr ovide?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

What ar e t he new br oadcast m et hod s included in I Pv 6?

I SBN: 1- 58 705 -1 19 -2 Pages: 28 6 : 11What

is un icast ?

7:

What is m ult icast ?

8:

What is any cast ?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • ht t p: / / w w w - 6bon e. lbl. gov / 6b one •

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•• ht t p: / / w w w I.ndex cisco.com / w ar p/ cust om er / 7 32/ ipv 6/ in dex. ht ml I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By • htCisco t p: / /Systems, w w w . ietInc. f .or g / ht m l. ch art er s/ ipngw g - ch ar t er . ht m l Pub lish er: Cisco Press

• ht tPub p: / Dat / play gr oun d. Sun. COM: 80 / pub / ipng / ht m l e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 37. NetWare Protocols Obj e ct i ve s • •

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I nt r odu ce t he Net War e pr ot ocol I PX/ SPX, used pr imar ily in Nov ell- based net w or k s. I ndex

I nt e rn Discuss et w or k ingt he Te chnologie H aand ndbook , Four th Editof ion st r uct urses f unct ioning t h is By Cisco 19Systems, 80s t o itInc. s cur r en t

pr ot ocol, fr om it s in t rod uct ion in t h e early

f or m.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background Net War e is a n et w or k op er at ing syst em ( NOS) t hat pr ov ides t r anspar ent r em ot e file access an d nu mer ous ot her dist r ib ut ed net w ork ser vices, in clu ding pr int er shar ing and supp or t f or v arious app licat ions su ch as elect r onic m ail t ran sf er and dat ab ase access. Net War e specif ies t he up per •fiv e lay er s of Table of Content t h e OSI r efer sen ce mod el and, as such, r un s on any m edia- access pr ot ocol ( Lay er •2) . Addit ionally I ndex , Net War e r uns on v irt ually any k ind of comp ut er syst em , f rom PCs t o Im ntainfr e rn etam w ores. k ingThis Te chnologie a ndbook , Fourtth ion chapt ers Hsum m ar izes heEdit p rincipal com m un icat ions pr ot ocols t hat su ppor t NetCisco WarSystems, e. By Inc. Net War e w as dev eloped by Nov ell, I n c. , an d was in t r oduced in t h e ear ly 1 980s. I t w as der ived Pub lish er: Cisco Press fr om Xer ox Net w ork Syst em s ( XNS) , w hich was cr eat ed b y Xerox Cor por at ion in t he lat e 197 0s, Dat e: Sep tem ber 1 1, 2 003 andPub is based on a client - ser ver ar chit ect ur e. Clien t s ( som et im es called w ork st at ions) r equ est I SBN: 1- 58as 705file -1 19and -2 ser v ices, such p rin t er access, f r om ser v er s. Pages: 11 28

Net War e' s client / ser ver ar chit ect ur e supp ort s rem ot e access t h at is t r ansp arent t o u ser s t h rou gh r em ot e pr ocedu re calls. A r em ot e pr oced ur e call begins wh en t h e local com p ut er pr ogr am r unn ing on t he client sen ds a pr oced ur e call t o t h e r em ot e ser ver . The ser ver t h en ex ecut es t h e r em ot e pr ocedu re call an d ret ur n s t he r equest ed in for m at ion t o t he local client . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Figur e 37 - 1 illust r at es t he Net War e p rot ocol su it e, t he m edia- access pr ot ocols on wh ich Net War e essent ial an d cu t t ing- edg e t ech nologies. r uns, an d t he r elat ion sh ip b et w een t he Net War e pr ot ocols and t he OSI r ef erence m odel. This chapt er ad dr esses t he element s and oper at ions of t hese pr ot ocol com ponent s. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Figuchapt r e 3er7s-1 . Th ecov Ne t Wear ocol Suilike t e VoI M aPps Al l New include erag of eimPr porot t ant t opics andt o EAP

OSI La ye r s

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

NetWare Media Access The Net War e suit e of p rot ocols sup por t s sev er al m ed ia- access ( Lay er 2) pr ot ocols, in clud ing Et h er n et / I EEE 802 .3 , Tok en Rin g/ I EEE 80 2. 5, Fiber D ist r ibut ed Dat a I nt er face ( FDDI ) , an d Point - t o- Poin t Pr ot ocol ( PPP) . Figur e 37 - 2 h ighligh t s Net War e' s br eadt h of m ed ia- access su ppor t . •

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Figu r e 3 7 -2 . N et W a r e Suppor t s M ost Com m on M e dia - Access Pr ot ocols

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Internetwork Packet Exchange Overview I n t ern et w or k Pack et Ex change ( I PX) is t he or iginal Net War e n et w or k lay er ( Lay er 3) pr ot ocol used t o r out e p acket s t h rou gh an in t ern et w or k . I PX is a connect ionless d at agr am - based n et w or k pr ot ocol an d, as such, is sim ilar t o t he I nt er net Pr ot ocol f oun d in TCP/ I P net w ork s. •

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•I PX u ses t h e Iser ndex v ices of a d yn am ic dist ance vect or r out in g p rot ocol ( Rout in g I nf or m at ion IPr ntot e rn et w or k ing chnologie a ndbook , Four ion( Net W are Link - St at e Pr ot ocol [ NLSP] ) . I PX RI P ocol [ RI P] )Teor a link - sstHat e r out in g p th r otEdit ocol sen ds r out in g u pdat es ev er y 6 0 seconds. To mak e b est - p at h r ou t ing decisions, I PX RI P uses a By Cisco Systems, Inc. t ick as t he m et r ic, w h ich in pr incip le is t he d elay ex pect ed w hen using a p art icular leng t h. One t ick is 1/ 1 8t h of a secon d. I n t he case of t w o pat hs w it h an equal t ick coun t , I PX RI P uses t he Pub lish er: Cisco Press hop count as a t ie- b r eak er. ( A hop is t h e passage of a packet t hr ough a rou t er. ) I PX' s RI P is not e: Sep tem ber 1 1, 2 003 comPub patDat ible w it h RI P im plem en t at ions used in ot h er net w ork ing env iron ment s. I SBN: 1- 58 705 -1 19 -2

As w it Pages: h ot her 11 28 net w or k add resses, Nov ell I PX net w or k addr esses m ust be un ique. Th ese add resses ar e r epr esent ed in h ex adecim al for m at an d con sist of t wo par t s: a net w or k num b er and a node n um ber . The I PX net w ork n um ber , w hich is assigned by t he net w or k adm inist r at or , is 32 bit s lon g. Th e nod e num ber , w hich usually is t he Med ia Access Con t r ol ( MAC) add ress for one of t he syst em 's n et wor k in t er f ace car ds ( NI Cs) , is 48 bit s long . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of I PX's u se of a MAC add ress for t he n ode nu m ber en ables t he sy st em t o send nodes t o pr edict essent ial an d cu t t ing- edg e t ech nologies. w hat MAC addr ess t o u se on a dat a lin k. ( I n cont r ast , b ecause t h e host por t ion of an I P n et w or k add ress has no cor r elat ion t o t he MAC add ress, I P nod es mu st use t h e Addr ess Resolu t ion Pr ot ocol ARP]ovt o ersmofine t h e olog desties in atessen ion MAC Con[cise er dv et iew t echn t ial ad t o dr n etess. wor) k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IPX Encapsulation Types Nov ell Net War e I PX sup por t s m ult iple encapsulat ion schemes on a sing le rou t er int er face, pr ov ided t hat m u lt ip le net w ork num ber s ar e assig ned. En cap sulat ion is t he pr ocess of p ack agin g up per- lay er pr ot ocol inf or mat ion and d at a int o a f r ame. Net War e sup por t s t he follow in g four •encapsulat ion Table of Content schem es: s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

N ov el l Pr opr ie t ar y— Also called 8 02. 3 r aw or Nov ell Et h er net _8 02. 3 , Novell p rop riet ar y ser v es as t he in it ial en capsulat ion schem e t hat Nov ell u ses. I t in clud es an I n st it u t e of Elect rical an d Elect r onic Engineers ( I EEE) 80 2. 3 Lengt h f ield, but not an I EEE 802 . 2 ( LLC) Pub lish er: Cisco Press header . The I PX header im mediat ely f ollow s t h e 80 2. 3 Len gt h f ield.

By Cisco Systems, Inc.

Pub Dat e: Sep tem ber 1 1, 2 003

8 I0SBN: 2 . 3 1—58Also 705 -1called 19 -2 Nov ell_ 802 . 2, 80 2. 3 is t he st and ar d I EEE 802 .3 f ram e f or mat . Pages: 11 28

Et he rn et ve r si on 2 — Also called Et her net - I I or ARPA, Et her net v er sion 2 inclu des t he st andar d Et h er n et Ver sion 2 h ead er , w h ich consist s of Dest in at ion an d Sou rce Ad dr ess fields f ollowed by an Et herTy pe field . SN A P— Also called Et her net _SNAP, SNAP ex t ends t he I EEE 8 02. 2 header by pr ovid in g a The utpdat edit ionilar of ttohet hbat estd-ef selling one orksion ing r2efspecif erence p rov y pe ed code sim ined inallt hine Et h ernet netwver icat ion.ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Figur e 37 - 3 illust r at es t hese encapsulat ion t yp es. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Figu r e 3 7 -3 . Four I PX Enca psul at ion Type s Ex ist

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Service Advertisement Protocol The Serv ice Ad ver t isem en t Pr ot ocol ( SAP) is an I PX pr ot ocol t hr oug h w h ich net w or k r esour ces such as file ser v ers and pr int ser ver s adv ert ise t h eir ad dr esses and t he ser vices t hat t hey pr ov ide. Adv ert isement s ar e sent v ia SAP ev er y 6 0 seconds. Ser vices ar e ident ified by a •hex adecim al Table of Content s is called a SAP ident if ier ( for ex am ple, 4 = file serv er, and 7 = pr int n um ber , w hich •ser v er) . I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

A at ionInc. b eg ins w hen rou t ers list en t o SAPs an d b uild a t able of all kn own serv ices alon g By SAP Ciscooper Systems, w it h t heir net w or k addr ess. Rout er s t hen sen d t h eir SAP t able ev er y 6 0 seconds. Nov ell client s can send a quer y r eq uest in g a par t icular file, pr int er , or g at eway ser vice. The local r out er Pub lish er: Cisco Press r espon ds t o t he quer y w it h t he net w or k add ress of t he r equ est ed ser vice, and t he client t hen can e: Sep tem ber 1 1, 2 003 contPub actDat t he ser v ice dir ect ly . I SBN: 1- 58 705 -1 19 -2

SAP isPages: p er v asiv 11 28 e in cur rent net w or k s based on Net War e 3. 11 and ear lier , bu t it is ut ilized less fr equ en t ly in Net War e 4. 0 net w or ks becau se wor k st at ions can locat e ser vices by consult in g a Net War e Dir ect or y Serv ices ( NDS) Ser ver . SAP, h ow ev er, st ill is r equ ir ed in Net War e 4. 0 net w or ks for w or k st at ion s w hen t hey boot up t o locat e an NDS ser v er . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. SAP Filters Using t h e SAP ident if ier , SAP adv ert isement s can b e filt ered on a r out er 's in put or ou t put por t , or Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom fr om a specif ic r out er. SAP f ilt er s conser v e net w or k ban dw idt h and ar e esp ecially usef ul in lar ge nov ice t o ex pert . Nov ell in st allat ions wh er e h und reds of SAP ser v ices ex ist . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP I n general, t he use of SAP filt ers is recom mend ed f or ser v ices t h at ar e not r eq uir ed f or a par t icular net w . Rem e sit es, f orologies exam ple, robical ablyn do notk ing needand t o st r eceiv e SAP adv er t ising Cov erag e or ofkcut t ingotedge t echn lik epopt et wor or age pr int ser v ices locat ed at a cent r al sit e. A SAP out p ut f ilt er at t h e cen t ral sit e ( pr ef err ed) , or a SAP inpu t Aut f ilt er t hat by uses t heSy SAP id en twifier foride a pr int serinv er t h king e r emf or ot et he sit eI npt er rev en. t s t he rou t er h ored Cisco st ems, or ldw leader netat w or n et fr om in clu ding pr int ser v ices in SAP up dat es. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

NetWare Transport Layer The Sequenced Pack et Ex chan ge ( SPX) p r ot ocol is t he m ost com m on Net War e t r an sp ort pr ot ocol at Lay er 4 of t h e OSI m odel. SPX resides at op I PX in t he Net War e Pr ot ocol Suit e. SPX is a r eliable, conn ect ion- or ient ed pr ot ocol t hat supp lem ent s t h e dat ag ram ser vice pr ov ided by t he •I PX, Net War e' Table ofwContent s s net or k layer ( Layer 3 ) p rot ocol. SPX w as der iv ed fr om t h e Xer ox Net w or king •Sy st em s ( XNS) I ndex Seq uenced Pack et Pr ot ocol ( SPP) . Nov ell also off er s I nt er net Pr ot ocol sup por t in It he nt e rn w or chnologie s Hram a ndbook Edit ion foretm ofk ing t h eTeUser Dat ag Prot, Four ocolth( UDP) . I PX dat ag r ams are encap su lat ed inside UDP/ I P header for t r anspor By Cisco sSystems, Inc. t acr oss an I P- b ased int er net w ork . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

NetWare Upper-Layer Protocols and Services Net War e su ppor t s a w ide v ar iet y of u pper - layer p rot ocols, includin g Net War e Shell, Net War e Rem ot e Pr oced ur e Call, Net War e Cor e Pr ot ocol, and Net wor k Basic I npu t / Ou t put Sy st em . •The Net War eTable Content s s ( oft en called w or k st at ions in t he Net War e com mu nit y ) an d shellofr un s client •int er cept s applicat I ndex ion in put / out pu t ( I / O) calls t o det er m in e w het her t h ey r equir e n et w or k access Ifor nt e com rn et wpor H a ndbook , Four th rEdit letk ing ion.TeI chnologie f t h e apps licat ion r eq uest eq ion uir es n et wor k access, t h e Net W are sh ell p ack ages tBy heCisco requSystems, est andInc. sen ds it t o low er - lay er sof t w ar e for pr ocessin g an d net w ork t ran sm ission . I f t he app licat ion r eq uest does not r eq uir e net w or k access, t he r equest is p assed t o t h e local I / O r esour ces. Clien t ap plicat ion s are unaw ar e of any net w ork access r equ ir ed for com plet ion of Pub lish er: Cisco Press app licat ion calls. Pub Dat e: Sep tem ber 1 1, 2 003 1- 58 -1 19 -2 Net WarI SBN: e Rem ot705 e Pr ocedu re Call ( Net War e RPC) is anot h er mor e g en er al r edir ect ion m echan ism similarPages: in concep 11 28 t t o t he Net War e shell supp or t ed by Novell.

Net War e Cor e Pr ot ocol ( NCP) is a series of ser v er r out ines designed t o sat isfy ap plicat ion r eq uest s coming f r om, for ex amp le, t he Net War e shell. The serv ices p rov ided by NCP include f ile access, pr int er access, nam e m anag em ent , accoun t ing, secur it y, and file syn chr onizat ion. The u pdat ed edit ion of estw- selling all-Iinnetpu w ork r ef (erence p rovsession ides cover ageintofer face Net War e also suppor t s tt he he bNet or k Basic np one ut / Out t Sying st em Net BI OS) lay er essent ial an d cu t t ingedg e t ech nologies. specif icat ion f rom I BM and Micr osof t . Net War e's Net BI OS em ulat ion sof t w ar e allows pr ogr am s w r it t en t o t he in dust r y- st an dar d Net BI OS int erf ace t o r un w it hin t h e Net W are sy st em . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

NetWare Application Layer Services

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Net War e applicat ion lay er ser v ices includ e Net Ware messag e- hand lin g serv ice ( Net War e MHS) , Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Bt r iev e, Net War e loadable m odu les ( NLMs) , and I BM Logical Unit ( LU) 6. 2 net w or k- addr essable un it s Aut ( NAUs) . Net e MHS is a mwessag d eliv er y sy emwtor hat p r ovides onic h ored by War Cisco Sy st ems, or ldweide leader instnet king f or t he elect I n t err n et . m ail t r anspor t . Bt r ieve is Novell's im plem en t at ion of t he bin ary t ree ( b t ree) d at abase- access m ar enologies add - on Hand mod ules attthach t o a, is Net st em . NLMs r ent hat t ly I n ech t ernanism et w or.kNLMs in g Tech bookt ,hat Four Ed in it ion a Ware com prsy ehensive refercur ence av ailab le fr om Nov ell and t hir d par t ies in clu de alt ern at e pr ot ocol st ack s, com m unicat ion enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing ser v ices, and dMast at abase v ices. I n tcep er mt s, s of I BMologies, LU 6. 2 an NAU su ppor tused , Net War e allow s peer ot echnologies. er t heser t er m s, con t echn d devices in t oday ' s net w ork- ting peer connect ivit y an d in for m at ion ex chang e acr oss I BM net w ork s. Net War e packet s ar e indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . encapsulat h inan LUd 6. 2 packet s f orert rsansit acr oss I BM netopt w or k . net w or k in g, scalabilit y, Com plet e wed it hwit new u pdat ed chapt on secur it y ,an st or age, ical and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IPX Packet Format The I PX packet is t he b asic u nit of Nov ell Net Ware in t ern et w or k ing. Figur e 37 - 4 illust r at es t he for m at of a Net War e I PX pack et . •

Table of Content s

•

I ndex

Figu r e 3 7 -4 . A N et W a r e I PX Pack et Con si st s of 1 1 Fie ld s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy The f ollow inovid g d escr ions m ar stwrat in en Figur e 37ent - 4: s in w hich syst em s, pr in g ipt am or esum r ealist icize pictt he ur eI PX of tpacket he real-field w orsldillu n et ored k ing vir onm pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Che ck I n dicat decisions forsum t h eir—net w orkes s. t hat t he checksum is not used w hen t his 1 6- bit field is set t o 1s ( FFFF) . Pack e t l eng t h— Specif ies t h e len gt h , in b yt es, of a com p let e I PX dat agr am . I PX p ack et s can be any leng t h, u p t o t h e media m axim um t ran sm ission un it ( MTU) size ( no p ack et fr ag ment at ion allow ed ) .

Tra nspor t cont r ol— I n dicat es t he nu m ber of r out ers t hr ough w hich t he p ack et h as passed . When t his v alue r eaches 16, t he p ack et is d iscar ded under t he assu m pt ion t hat a r out ing loop m ig ht be occur rin g. Pack e t t y pe — Specif ies w h ich up per- lay er pr ot ocol should r eceive t he pack et 's inf orm at ion. I t has t w o com mon v alues: • •

- 5 — Specif ies Sequ en ced Packet Exch ange ( SPX) Table of Content s

- 1I ndex 7 — Specif ies Net War e Cor e Pr ot ocol ( NCP)

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

D e st i na t ion ne t w ork , D e st ina t i on n ode, an d D e st ina t i on sock et — Specif y dest in at ion inf orm at ion. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Sou rce ne t w or k , Sou rce node , a nd Sour ce sock e t — Specif y sou r ce in for m at ion. I SBN: 1- 58 705 -1 19 -2

UPages: ppe r11La 28 ye r da t a— Cont ains infor m at ion for u pper - layer p rocesses.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary I PX is st ill inst alled in m illions of com pu t er s in t h e Net W are n et wor k s. How ev er, t her e has b een a lar ge chang e fr om I PX t o I P w it h in t h ose en vir onm ent s, and t h is t r en d is lik ely t o cont inu e, w it h Nov ell sup por t ing nat iv e I P w it hin it s n et w or k ing en vir onm ent s. •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What ar e t he t w o t y pes of r out ing pr ot ocols used by I PX?

2:

I ndex inf orm at ion is used by I PX RI P t o d et er m ine a pat h for n et wor k t raf fic? What

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : What By Cisco Systems, Inc.ar e 4:

t he t w o par t s of an I PX ad dr ess?

How d o Nov ell st at ion s discov er ser v ices av ailable on t he n et wor k ?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

What pr ot ocol is u sed at t he t r anspor t lay er ?

I SBN: 1- 58 705 -1 19 -2 Pages: 28 6 : 11How

d o I PX st at ions map t h e MAC addr ess t o an I PX ad dr ess?

7:

What enhan cem ent in Net War e 4. 0 r ed uces t he need for SAPs?

8:

What ser v ices ar e p rov ided by Net War e Cor e Pr ot ocol?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of ibe edg Net War e'snologies. sup por t of Net BI OS. essent ial9 :an dDescr cu t t inge t ech 1 0 : Would y ou wan t t o filt er SAPs? Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 38. AppleTalk Obj e ct i ve s • •

Table of Content s

Descr ibe t he dev elop ment hist or y of t he Ap pleTalk pr ot ocol, used alm ost exclusiv ely in I ndex Macint osh com p ut ers.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Descr Systems, ibe t he Inc.com ponent s

of Ap pleTalk net w ork s an d ex t ended net w ork .

Discuss t he p rim ar y char act er ist ics of t he App leTalk p rot ocol.

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

Discuss t he ad dr essing m et h ods of Ap pleTalk . I SBN: 1- 58 705 -1 19 -2

Descr Pages: ibe 11 28ad dit ional pr ot ocols im plem en t ed in App leTalk net w or k s, in clu ding pr ot ocols used in t he u pper lay er s of t h e OSI r efer en ce mod el.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction App leTalk , a pr ot ocol suit e dev elop ed by Apple Comp ut er in t he ear ly 198 0s, w as dev elop ed in conj unct ion w it h t h e Macint osh com pu t er. AppleTalk' s pu rp ose was t o allow m ult ip le user s t o shar e r esour ces, su ch as f iles an d pr in t ers. Th e devices t hat supp ly t hese resour ces ar e called •ser v ers, w hile Table Content t h eofdev ices st hat m ak e use of t hese r esour ces ( such as a user 's Macint osh •com put er ) arIendex r efer red t o as client s. Hence, AppleTalk is one of t h e early im plem en t at ions of a Idist nt e rn et wed or k ing Te chnologie s et H aw ndbook Edit ion r ibut client / ser ver n or k in ,gFour sy stthem. This chapt er p rov ides a su mm ar y of App leTalk 's netCisco w or kSystems, ar ch it ect u re. By Inc. App leTalk w as d esigned w it h a t r anspar ent net w ork in t er f ace—t h at is, t h e int eract ion bet w een Pub lish er: Cisco Press client com put er s and net w or k ser v er s r equ ir es lit t le int er act ion f rom t he u ser . I n addit ion, t he Pub Dat e: Sep tem ber 1 1, 2 003 act ual op er at ion s of t he Ap pleTalk p rot ocols ar e inv isible t o end u ser s, w ho see only t h e r esult of I SBN:at 1-ions. 58 705 -1 19o-2v er sions of AppleTalk ex ist : Ap pleTalk Ph ase 1 an d Ap pleTalk Phase 2. t hese oper Tw Pages: 11 28

App leTalk Phase 1 , w hich is t he f ir st Ap pleTalk sp ecificat ion, was developed in t h e early 1 980 s st r ict ly f or use in local w ork gr oup s. Phase 1 t her ef or e has t w o key lim it at ions: I t s n et w or k seg m en t s can cont ain no m or e t han 13 5 h ost s and 135 serv er s, and it can su ppor t only non ex t ended net w or ks. Ext end ed an d n onext en ded n et w or k s w ill be d iscussed in det ail lat er in tThe he sect ions Ex t ended ork-s" and "allNonex t en ded or krs. u pdat ed "edit ion of tNet he w b est selling in- one net wNet orkwing ef"erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. App leTalk Phase 2 , w hich is t he secon d enh anced App leTalk im plem en t at ion, w as d esign ed f or use in larg er int ern et wor k s. Phase 2 addr esses t h e k ey lim it at ions of Ap pleTalk Ph ase 1 an d feat u res num pr ov em ent s ies overessen Phase par t icu lar ,pr Phofession ase 2 allow s an com at ion Conacise ovber er v of iewim s of t echn olog t ial1 t.oI nn et wor k ing als at all ylev els,b in f rom of 25 3nov h ost s or ser v ers on a sin gle App leTalk net w or k seg m en t and sup por t s bot h n onext end ed ice t o ex pert . and ext en ded n et wor k s. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

AppleTalk Network Components App leTalk net w or k s ar e arr an ged h ier ar ch ically . Four basic com ponent s for m t h e basis of an App leTalk net w or k : socket s, nod es, n et w or k s, and zones. Figur e 38 - 1 illust r at es t he hier ar chical or ganizat ion of t hese com ponent s in an App leTalk int er net w or k. Each of t h ese concept s is •sum m arized Table Content in t heof sect ionss t hat follow . •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 3 8 -1 . Th e Appl eTa lk I n t e r ne t w or k Con sist s of a Hi er a r ch y of Com p on e nt s Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Sockets An App leTalk sock et is a un iq ue, add ressable locat ion in an AppleTalk node. I t is t he log ical p oint at wh ich up per - lay er App leTalk soft war e p rocesses and t h e net w or k layer Dat agr am Deliver y Pr ot ocol ( DDP) int er act . These upp er - lay er pr ocesses ar e k now n as socket client s. Sock et client s

ow n one or m or e socket s, w hich t hey use t o send an d r eceiv e dat ag ram s. Sock et s can be assig ned st at ically or dy nam ically . St at ically assig ned socket s ar e r eser v ed f or use by cer t ain pr ot ocols or ot h er pr ocesses. Dy nam ically assign ed sock et s ar e assig ned b y DDP t o sock et client s up on r equ est . An App leTalk n ode can con t ain u p t o 25 4 d iff er ent sock et nu mb er s. Figur e 38 - 2 illust rat es t he r elat ion sh ip b et w een t he sock et s in an AppleTalk node and DDP at t h e net w or k lay er . • •

Table of Content s I ndex

Figu r e 3 8 -2 . Sock et Clie n t s Use Sock e t s t o Se nd a nd Re ce iv e Da t a gr a m s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Nodes Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all An App leTalk n ode is a dev ice t hat is con nect ed t o an Ap pleTalk n et w or k . This d ev ice m ig ht be a net w or kin g p rof essionals, r egar dless of ex pert ise. Macint osh com p ut er, a p rint er , an I BM PC, a rou t er , or som e ot h er sim ilar dev ice. Wit h in each App leTalk nod e exist n um erou s soft w ar e pr ocesses called sock et s. As discu ssed ear lier , t he Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e fu nct ion of t hese sock et s is t o ident if y t h e sof t w ar e pr ocesses ru nning in t he device. Each node in har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on an AppleTalk net w or k belongs t o a sing le net w or k and a specific zone. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Networks pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr iv it y an im pr eff iciency, help t he cable r eaderand m ake mor in ttached elligentnod , cost Anodu AppctleTalk n etdwor k ov cone sist s of a sing le ing logical m ult iplee at es.- eff Th icient e logical decisions for t h eir net w ork s. cable is com pr ised of eit h er a single p hy sical cable or m u lt ip le phy sical cab les in t er connect ed b y using br idg es or rou t ers. Ap pleTalk n et wor k s can be non ex t end ed or ex t en ded. Each is d iscussed br iefly in t he f ollow in g sect ion s.

Nonextended Networks

Anon ex t ended App leTalk n et wor k is a ph ysical net w or k seg ment t hat is assig ned on ly a single net w or k nu mb er , w h ich can r an ge bet w een 1 and 10 24. Net w or k 1 00 and net w or k 562 , for exam ple, ar e b ot h v alid net w ork num ber s in a non ex t ended net w or k. Each node n um ber in a non ex t ended net w or k m ust b e uniq ue, and a sing le nonex t en ded net w ork segm ent can not hav e m or e t han one Ap pleTalk Zone conf ig ur ed on it . ( A zone is a logical gr oup of nod es or net w or ks. ) App leTalk Phase 1 supp or t s only n onext end ed net w or k s, but as a r u le, n onext end ed n et w or k conf ig ur at ions ar eofno longer • Table Content s u sed in new net w or ks becau se t hey hav e been sup er seded b y ext end ed n et w or k s. Figur e 38 - 3 illust r at es a n onext en ded Ap pleTalk n et wor k . • I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 3 8 -3 . A N on ex t e nd ed Ne t w or k I s Assi gn ed O nl y On e Ne t w or k Pub lish er: Cisco Press Nu m be r Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Extended Networks Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n text ernend et wed or kAp in gpleTalk Tech nologies , Four t hwEd is a com ehensive refer ence t hat An net w or kHand is a book ph ysical net or kit ion seg, ment t hatprcan be assig ned m u lt ip le enables w orerkin p r ofessionals t o un im plem t cont em por ar y intrer net w ork net w or k net nu mb s. gThis con figur at ion is derst k nowand n asana dcable r anen ge. AppleTalk cable anges caning t echnologies. Mast erwtor hek tnu er m s,ercon t s,iple t echn ologies, used in tTh oday ' s netrw ork ing indicat e a sin gle net mb orcep m ult consecu t iveanndetdevices w or k n um bers. e cable anges induwst Lear how o incor netex w or g t ar echn olog in tino a WAN env . net orry k . 33 ( un nar y) tand netpor w oratk e3-int 6 ,erfor amkin ple, e bot h vies alid anLAN/ ex t ended netirwonm or k. ent Just Com e wpitrot h new d es, u pdat ed as chapt erIsPon , st orcomb age, inopt ical of netnet w or in g,n um scalabilit y, as inplet ot her ocol an suit such TCP/ an secur d I PX,it yeach at ion w kork ber and and espeed, t h is isend a com p- t oat eique, r ef erand enceit st oadt he t op ics t hat essenfor t ial t o all nod num b er in book an ext ed nplet et weoran k dmuust bedun dr ess m u st beare u nique net w or kin ion g p rof egar dless oforex ident if icat puessionals, rp oses. Ex rt ended net w kspert canise. hav e m ult ip le Ap pleTalk zones config ur ed on a single n et w or k segm en t , and nod es on ex t ended net w or ks can belong t o an y single zon e Reader w illwit obt g reat er un ding LAN WAN w orcon k ing, ar tion icu slarhav ly teh reep laced associatsed h ain t h e aext end ed netder w orstkan . As a rof u le, ex tand ended netnwetork figuprat har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is non ex t ended net w or k config ur at ions. Figur e 38 - 4 illust r at es an ex t end ed net w or k. pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, a m or ic pict real- wBe or ldAssig n et w orne k ing enu virltonm entNe s int w w hich Figu r epr3ovid 8 -4in.g An Exetreealist nd ed Neurt ewofort he k Can dM ipl e or k pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Nu m be r s pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

•

Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Zones The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of An App ial leTalk one is aedg logical grnologies. oup of n odes or net w or ks t hat is defined w hen t he net w or k essent an dz cu t t inge t ech adm inist r at or conf ig ur es t he n et w or k . The nodes or n et w or k s need n ot b e phy sically cont ig uous t o belon g t o t h e sam e Ap pleTalk zone. Figur e 38 - 5 illust r at es an AppleTalk int er net w ork com posed of tov hr er eev iew nonscon s zones. Con cise of ttiguou echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Figu r e 3 8 -5 . N od es or Ne t w or ks i n t h e Sa m e Zone N ee d Not be

Cov erag e of cut t ing edge t echn ologies ical wors k ing and st or age Phy sica lik ll ye opt Con t ign et uou

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

AppleTalk Physical and Data Link Layers As w it h ot her pop ular p rot ocol suit es, such as TCP/ I P an d I PX, t he App leTalk ar chit ect ur e m aint ains m edia- access d ep en dencies on such low er - layer p rot ocols as Et her net , Tok en Rin g, and FDDI . Four main m ed ia- access imp lem ent at ions ex ist in t he Ap pleTalk pr ot ocol su it e: •Et h er Talk , LocalTalk, Table of Content s TokenTalk , an d FDDI Talk . •

I ndex

IThese nt e rn etdat w orak ing chnologie s H a ndbook , Fourpth ion addr ess t ran slat ion and ot h er fun ct ion s t hat allow lin kTelayer im plem en t at ions erEdit f orm pr opr iet ar y AppleTalk pr ot ocols t o com m unicat e ov er indu st r y - st andar d int er faces, wh ich includ e By Cisco Systems, Inc. I EEE 8 02. 3 ( using Et h er Talk ) , Tok en Rin g/ I EEE 80 2. 5 ( using TokenTalk ) , an d FDD I ( using FDDI Talk) . I n ad dit ion, Ap pleTalk im plem en t s it s ow n net w or k int er face, kn ow n as LocalTalk . Pub lish er: Cisco Press Figur e 38 - 6 illust r at es how t he App leTalk m edia- access im plement at ion s m ap t o t h e OSI Pub Dat e: Sep tem ber 1 1, 2 003 r ef erence m odel. I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 3 8 -6 . Apple Tal k M e dia - Access I m ple m en t a t i on s M a p t o t h e Bot t om Tw o La ye r s of t h e O SI Ref er e n ce M ode l The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.[ View full size im age] Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, EtherTalk and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Et h er Talk ex t ends t he dat a link lay er t o enab le t he App leTalk p rot ocol su it e t o op er at e at op a st andarsd wI EEE 8 ain 02. 3a imp lem ion. Etding h er Talk net w or ks are norg EEE Reader ill obt g reat erent unat der st an of LAN and WAN et wanized or k ing,expact ar tly icuas larIly t h e80 2. 3 net w or ks, sup por t ing t he sam e speeds and segm en t leng t hs, as w ell as t h e sam e n um berided of on har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov act ive net w ork n odes. This allow s AppleTalk t o be deploy ed ov er any of t he t hou sands of a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Et er su n etre- bcon ased netcomp w or ks inen exsion ist ence Comand mu nicat b etrw eenr ces t he fup ot .ocols t o hen cept r eh and trod et ay. en t ion, ad dition ional esou or per fu rt- lay hererstpr udy of t he AppleTalk archit ect ur e an d t h e Et h er net pr ot ocols is hand led by t he Et herTalk Lin k Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Access Pr otem ocols, ( pr ELAP) syst ovid.in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient EtherTalk Protocol decisions forLink t h eirAccess net w ork s. The Et h er Talk Link Access Pr ot ocol ( ELAP) h andles t h e int eract ion bet w een t h e pr opr iet ary App leTalk pr ot ocols and t h e st andar d I EEE 80 2. 3 dat a lin k layer . Upper - layer App leTalk pr ot ocols do not recognize st an dar d I EEE 802 . 3 h ard w are addr esses, so ELAP uses t he Addr ess Map ping Table ( AMT) m aint ained by t h e AppleTalk Addr ess Resolu t ion Pr ot ocol ( AARP) t o

pr oper ly addr ess t r ansm issions. ELAP han dles t he in t er act ion bet w een upp er - lay er pr ot ocols of AppleTalk and t he d at a link lay er by encap su lat in g or en closing t he dat a in sid e t he p rot ocol unit s of t h e 80 2. 3 d at a link lay er. ELAP per for m s t h ree levels of encapsulat ion w hen t ran sm it t ing DD P pack et s: Sub net w ork Access Prot ocol ( SNAP) header • •

Table of Content s I ndex I EEE 8 02. 2 Logical Link Con t rol ( LLC) h ead er

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

I EEE 8 02. 3 header

By Cisco Systems, Inc.

This p rocess of en cap su lat ion p er f orm ed by t h e ELAP is det ailed in t he f ollowin g sect ion. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 SBN: 1- Transmission 58 705 -1 19 -2 ELAPI Data Process Pages: 11 28

ELAP uses a sp ecific p rocess t o t r an sm it d at a acr oss t he p hy sical m edium . Fir st , ELAP r eceives a DDP pack et t hat r eq uir es t ran sm ission . Next , it f in ds t h e pr ot ocol add r ess specif ied in t he D DP header an d checks t he AMT t o find t he cor r esp onding I EEE 8 02. 3 har dw ar e add ress. ELAP t hen pr epends t hr ee diff er ent header s t o t h e DDP pack et , beginn in g w it h t h e SNAP and 80 2. 2 LLC The u pdat header s. The ed edit t h ird ionheader of t he is b est t h e- selling I EEE 80 all2. in3 header. one net w When ork ing pr ep r efen erence ding tphis rovheader ides cover t o tage h e pack of et , tessent he harial dwan arde cu addr t t ingessedg t akeent ech f rom nologies. t he AMT is placed in t he D est inat ion Add r ess f ield. The r esu lt , an I EEE 80 2. 3 fr am e, is placed on t he p hy sical m edium for t r ansm ission t o t he dest inat ion. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

LocalTalk

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP LocalTalk , w hich is a p rop r iet ar y dat a link lay er im p lem ent at ion developed by Ap ple Com pu t er erag e ofprcut t ing edge echn e opt ical- neff etect wor or ageion for conn ect ing for it sCov AppleTalk ot ocol suit e, t w as dologies esignedlikas a cost ivkeing netand w or kst solut local w or kg rou ps. LocalTalk har dw ar e t y pically is built in t o Ap ple pr odu ct s, w h ich ar e easily Auted h ored by Cisco Sy ems, ored ldw ide leader net w or king orort he I n et erorngan et . ized in a b us connect b y using inexp enstsiv e t wwist - pair cablingin . LocalTalk netf w ks ar t opolog y, wh ich m eans t h at dev ices ar e conn ect ed t o each ot h er in ser ies. Net w ork segm ent s ar e I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat limit ed t o a 30 0- m et er sp an w it h a max im um of 3 2 act iv e nodes, and m ult ip le LocalTalk enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing net w or ks can be in t erconn ect ed by u sing r out er s or ot h er sim ilar int er mediat e devices. Th e t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing com mu nicat ion b et w een t he dat a link lay er pr ot ocol LocalTalk and upp er - lay er pr ot ocols is t he indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . LocalTalk Link Access Prot ocol ( LLAP) . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

LocalTalk Link Access Protocol

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har ar e, pr ot ocols, and Prot ser vocol ices (inv olv ed entaccess al t echpr nology or mat is pr ov ided on Thedw LocalTalk Link Access LLAP) is. tFu hendam m ediaot ocolinf used in ion LocalTalk a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest net w or ks t o p rov ide b est - eff or t , err or - f ree deliv er y of f ram es bet w een App leTalk n odes. This ions tmo ean en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ed s t hat deliver y of dat ag ram s is not g uar ant eed b y t he LLAP; su ch a fu nct ion is p er f orm Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy only b y high er - lay er pr ot ocols in t h e AppleTalk ar ch it ect ur e. LLAP is r esponsible f or r eg ulat ing syst s, pr ovid am or e rm ealist pictduryn e amically of t he realoring ld ndat et waorlin k ing en virnod onm in w hich nod eem access t o tin heg ph ysical ed iaicand acqwuir k layer e ent addsresses. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for Node t h eir net w ork s. to the Physical Media Regulating Access LLAP im plement s a m edia- access sch em e k now n as car r ier sense m ult iple access collision av oidance ( CSMA/ CA) , w her eby nod es ch eck t h e lin k t o see w het her it is in u se. Th e link m ust b e idle f or a cer t ain r and om per iod of t im e b ef ore a nod e can b eg in t ran sm it t ing dat a. LLAP uses dat a exchan ges k now n as hand sh akes t o av oid collisions ( t hat is, sim ult aneous t r ansmission s by

t w o or m ore n odes) . A successfu l han dshak e bet w een nod es ef fect ively r eserv es t he lin k for t heir use. I f t w o n odes t r ansmit a h andshak e sim ult aneously, t he t r ansm issions collide. I n t his case, bot h t r ansm issions are dam aged, causing t he packet s t o be d iscar ded. Th e hand sh ake ex chang e is not comp let ed, and t he sendin g n odes inf er t hat a collision occur r ed. Wh en t h e collision occu r s, t he dev ice rem ains idle f or a r an dom per iod of t im e an d t hen r et r ies it s t r ansmission. This p rocess is sim ilar t o t he access m echanism used wit h Et hern et t ech nology . •

Table of Content s

Acquiring Node • I ndex Addresses I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

LLAP acqu ir es dat a link lay er node ad dr esses dy nam ically . The pr ocess allows a un ique d at a link By Cisco Systems, Inc. lay er ad dr ess t o be assigned w it hout per m anent ly assig ning t he ad dr ess t o t h e node. Wh en a nod e st art s up, LLAP assign s t he node a r andom ly chosen n ode ident if ier ( n ode I D) . The Pub lish er: Cisco Press un iq ueness of t his nod e I D is d et er m ined b y t he t ran sm ission of a sp ecial p ack et t h at is Dat e: Sep tem ber 1 1, 2 003 addPub ressed t o t he r and omly chosen node I D. I f t he nod e r eceives a reply t o t his p ack et , t h e node I SBN: 1- 58 e. 705The -1 19 -2 I D is not u niqu nod e t her ef or e is assign ed an ot her r andom ly chosen n ode I D and send s Pages: 28 out anot h er 11packet addr essed t o t h at n ode un t il no r ep ly ret ur ns. I f t h e acquir ing node does not r eceive a r ep ly t o t h e fir st q uery , it m akes a num ber of sub sequ en t at t em pt s. I f t h er e is st ill no r ep ly aft er t h ese at t em pt s, t he nod e I D is consider ed u nique, an d t he nod e uses t his n ode I D as it s dat a link lay er addr ess. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. TokenTalk Tok en Talk ex t ends t he dat a link lay er t o allow t h e AppleTalk pr ot ocol suit e t o oper at e at op a Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom st andar d I EEE 8 02. 5/ Tok en Ring imp lem ent at ion. TokenTalk n et wor k s ar e or ganized ex act ly as nov ice t o ex pert . I EEE 8 02. 5/ Tok en Ring net w or ks, sup por t ing t he sam e speed s and t he sam e n um ber of act ive net w or k nod es. er Comm un icat ionerag betew of eenimt por h e dat k layer rotP ocols sed w it h Tok en Ring and New chapt s include cov t anta tlin opics like pVoI and uEAP up per- lay er pr ot ocols is t he TokenTalk Lin k Access Pr ot ocol ( TLAP) . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy stProtocol ems, w or ldw ide leader in net w or king f or t he I n t er n et . TokenTalk Link Access I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat The Tok en Talk Lin k Access Prot ocol ( TLAP) h andles t h e int eract ion bet w een t h e pr opr iet ary enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing App leTalk pr ot ocols and t h e st andar d I EEE 80 2. 5 dat a lin k layer . Upper - layer App leTalk t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing pr ot ocols do not recognize st an dar d I EEE 802 . 5 h ard w are addr esses, so TLAP uses t he AMT indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . m aint ained by t h e AARP t o pr oper ly add ress t r ansm issions. TLAP per for m s t hr ee lev els of Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, encapsulat ion w hen t r an sm it t ing DD P pack et s: and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Sub net w ork Access Prot ocol ( SNAP) header Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dwI ar e, 8pr02. ot ocols, andLink ser vCon icest rol inv (olv ed . hFu ndam EEE 2 Logical LLC) ead er ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . I EEE 8 02. 5 header Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em TLAP s, prdat ovid a in trg ansmission a m or e r ealist p rocess ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease TLAP in eff volv es a nuhelp m ber st ep s t o t rm anake sm itmor dateainacr oss t he p hy -sical m edium . pr odudat ct ivait yt r ansmission an d im pr ov e iciency, ingoft he r eader t elligent , cost eff icient When TLAP DPs.p ack et t hat r equ ir es t r ansm ission, it fin ds t he pr ot ocol add ress decisions forreceiv t h eir es netawDork specif ied in t he D DP h ead er and t hen ch eck s t he AMT t o find t h e cor r esp ondin g I EEE 80 2. 5/ Tok en Rin g har dw ar e addr ess. Nex t , TLAP pr epends t hr ee diff er ent header s t o t he DDP pack et , beginn in g wit h t h e SNAP and 8 02. 2 LLC h ead er s. When t he t hir d h ead er , I EEE 80 2. 5/ Tok en Rin g, is p repend ed t o t he p acket , t h e har dw ar e add ress r eceived fr om t he AMT is placed in t he Dest in at ion Ad dr ess f ield. The r esu lt , an I EEE 80 2. 5/ Tok en Rin g f r ame, is p laced on

t he phy sical medium for t ran sm ission t o t he d est inat ion .

FDDITalk FDDI Talk ex t ends t he dat a link lay er t o allow t h e AppleTalk pr ot ocol suit e t o oper at e at op a st andar d ANSI FDDI im plem en t at ion. FDD I Talk n et wor k s ar e or ganized ex act ly as FDDI •net w or ks, sup Table Content s por tof ing t he sam e speeds and t h e same num ber of act iv e net w ork nodes. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

FDDITalk Link Access Protocol

By Cisco Systems, Inc.

lish Talk er: Cisco Press ThePub FDDI Link Access Pr ot ocol ( FLAP) h andles t h e int eract ion bet w een t h e pr opr iet ary Dat e:pr Sep ber 1and 1, 2 003 AppPub leTalk ottem ocols t h e st andar d FDDI d at a link lay er. Upp er - lay er AppleTalk pr ot ocols do not r ecogn andar d FD DI h ard war e ad dr esses, so FLAP u ses t h e AMT m aint ain ed by t he AARP I SBN:ize 1- 58st705 -1 19 -2 t o pr operly ad28 dr ess t ran sm ission s. FLAP per for m s t h ree levels of encapsulat ion w hen Pages: 11 t r ansm it t ing DDP packet s:

Sub net w ork Access Prot ocol ( SNAP) header The uIpdat edit of t he b est - selling all- inoneernet w ork ing r ef erence p rov ides cover age of EEE ed 8 02. 2 ion Logical Link Con t rol ( LLC) h ead essent ial an d cu t t ing- edg e t ech nologies. FDDI h ead er Con cise v iew of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom FLAP d atov a terran smsission pr ocess nov ice t o ex pert . As w it h TLAP, FLAP inv olves a mu lt ist ag e pr ocess t o t r ansm it dat a across t h e ph ysical m ed iu m . chapt er sesinclude erag of im port rt ant t opics like WhenNew FLAP r eceiv a DD P cov pack et reequir ing ansmission, it VoI findP s and t he pEAP rot ocol addr ess sp ecified in t he DD P h ead er an d t hen ch eck s t he AMT t o find t h e cor r esp onding FDDI har dw ar e addr ess. e of cut ing echn optDical wor ing and st or FLAP Cov t henerag p repend s tthr eeedge dif fert en t hologies ead er s tlik o et he DP n p et ack et ,k begin ning w age it h t he SNAP an d 80 2. 2 LLC header s. When t he t h ird header , t h e FD DI h ead er , is p repend ed t o t he p ack et , t h e by Cisco ems,t he w orAMT ldw ide leader in in tnet f or tAdd he Iress n t er n et . The r esult , har dwAut ar eh ored ad dr ess r eceivSy edstf rom is placed he w D or estking inat ion f ield. an FD DI f ram e, is p laced on t he ph ysical m ed ium f or t r ansm ission t o t h e dest in at ion. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Network Addresses App leTalk ut ilizes add resses t o ident if y and locat e devices on a net w or k in a m ann er sim ilar t o t he pr ocess ut ilized b y such com m on pr ot ocols as TCP/ I P an d I PX. These ad dr esses, wh ich ar e assig ned d yn am ically as discussed in t he f ollow ing sect ion , ar e comp osed of t hr ee elem ent s: •

Table of Content s

•

I ndex

wk ork be r— 16 - bit, value hation id en t ifies I nt e rn N et e w tor ing Tenum chnologie s HAa ndbook Four th tEdit By

a specific App leTalk n et w or k ( eit her

non ex t ended or ex t en ded) Cisco Systems, Inc. N ode num be r— An 8 - bit value t hat id en t ifies a p art icular Ap pleTalk node at t ach ed t o t he Pubspecif lish er: ied Cisconet Press w or k Pub Dat e: Sep tem ber 1 1, 2 003

Sock t 58 nu705 m-1 b 19 er-2— An 8 - bit num ber t h at ident if ies a specif ic sock et r un ning on a n et w or k I SBN:e1nod e Pages: 11 28 App leTalk add r esses usually are w rit t en as decimal valu es separ at ed by a p er iod. For ex am ple, 10 .1 . 50 means net w ork 10, node 1 , sock et 5 0. Th is also mig ht be r ep r esent ed as 10. 1, sock et 50 . Figur e 38 - 7 illust r at es t he Ap pleTalk net w ork addr ess for m at . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r e 3 8 -7 . Th e Appl eTa lk Ne t w or k Ad dr ess Con si st s of Thr e e Di st in ct Nut ial m be s wor k ing pr ofession als at all lev els, f rom Con cise ov er v iew s of t echn olog ies essen t o nr et nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is Address also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Network Assignment syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease On e of t he u nique ch aract er ist ics of App leTalk is t h e dy nam ic nat u re of device add resses. I t is pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient not necessar y t o st at ically define an ad dr ess t o an AppleTalk device. I nst ead, App leTalk n odes decisions for t h eir net w ork s. ar e assig ned ad dr esses dy nam ically w hen t hey f irst at t ach t o a n et wor k . When an AppleTalk net w or k node st ar t s u p, it r eceives a pr ovisional n et w or k lay er addr ess. The net w or k por t ion of t he p rov ision al add r ess ( t h e fir st 1 6 b it s) is select ed f rom t he st ar t up r ang e, w hich is a r eser ved r ange of n et w or k ad dr esses ( valu es 6 528 0 t o 65 534 ) . The node p ort ion ( t h e nex t 8 bit s) of t he p rov ision al add ress is chosen r and omly .

Using t h e Zone I nf or mat ion Pr ot ocol ( ZI P) , t h e nod e com m un icat es w it h a r out er at t ach ed t o t he net w or k. The r out er r eplies w it h t h e v alid cable r ange for t h e net w or k t o w h ich t he node is at t ached. Nex t , t h e node select s a v alid n et w or k nu m ber fr om t h e cable r ange su pplied b y t he r out er and t h en r and omly chooses a n ode n um ber. A b road cast message is used t o d et er m in e w het her t h e select ed add ress is in use by an ot her nod e. I f t he ad dr ess is n ot b eing u sed ( t hat is, no ot her nod e respond s t o t he b road cast w it h in a •specif ic per iod Table of tofimContent e) , t hes node h as successf ully been assign ed an addr ess. Howev er , if an ot her •nod e is usingI ndex t he ad dr ess, t h at n ode r esp onds t o t he br oadcast w it h a m essage in dicat ing t hat It he nt e rn addr et w ess or k ing is Te in chnologie u se. Th es Hnew a ndbook nod ,eFour m ust th Edit choose ion an ot her add ress and r epeat t h e pr ocess un t il it select s an addr ess t hat is not in u se. By Cisco Systems, Inc. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

AppleTalk Address Resolution Protocol App leTalk Ad dr ess Resolut ion Pr ot ocol ( AARP) is a net w or k layer p rot ocol in t h e AppleTalk pr ot ocol suit e t hat associat es Ap pleTalk net w ork ad dr esses w it h har dw ar e addr esses. AARP ser v ices ar e u sed by ot h er AppleTalk pr ot ocols. W hen an App leTalk p rot ocol has dat a t o •t r ansm it , for Table Content s ex amofple, it specifies t he n et wor k ad dr ess of t h e dest inat ion. I t is t he job of AARP t o •fin d t he har dw I ndex ar e ad dr ess t h at is associat ed w it h t he dev ice usin g t hat net w ork addr ess. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

AARP a r equest By Ciscouses Systems, Inc. - r espon se p r ocess t o lear n t he har d war e ad dr ess of ot h er net w ork nodes. Becau se AARP is a m ed ia- d ep en dent pr ot ocol, t he m et hod used t o r equest a har dw ar e add ress fr om a nod e var ies depend in g on t h e dat a link lay er im plem en t at ion. Ty pically, a br oad cast Pub lish er: Cisco Press m essage is sent t o all Ap pleTalk nodes on t he net w ork . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 Address Mapping Table

Each AppleTalk nod e con t ains an Add ress Mapp in g Table ( AMT) , w her e har dw ar e ad dr esses are associat ed wit h n et w or k add r esses. Each t im e AARP r esolves a net w or k and har dw ar e add ress com binat ion, t he m app in g is recor ded in t he AMT. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial e, antdhecupot t t inge t ech nologies. Ov er t im en t edg ial for an AMT ent r y t o becom e in valid increases. For t h is r eason, each AMT ent r y t y pically has a t imer associat ed w it h it . When AARP r eceiv es a pack et t hat v er if ies or chang es t he ent r y , t he t imer is r eset . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . I f t he t im er exp ires, t he en t ry is delet ed fr om t h e AMT. Th e next t im e an AppleTalk pr ot ocol w ant s t o com mu nicat e w it h t hat node, an ot her AARP requ est mu st be t ran sm it t ed t o d iscov er New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP t he har dw ar e addr ess. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in Address Gleaning

net w or king f or t he I n t er n et .

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Ienables n cer t ain im ions, incomting s darim e ex amen in ed t o em learpor n t ar heyhint ar er dwnet ar ew and net wplem or kinen g pt at r ofessionals o unDDP derstpacket and an plem t cont ork ing net w or k add resses of t h e sour ce node. DD P t h en can place t his inf orm at ion in t he AMT. is t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net wThis ork ing one w ay in w hich a d ev ice, such as a rou t er, wor k st at ion, or ser ver , can discov er devices w it hin indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . an AppleTalk w oran k. d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Com plet e w it hnet new and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all This p rocess of obt aining ad dr ess m app ings f r om incom in g packet s is k now n as add ress net w or kin g p rof essionals, r egar dless of ex pert ise. glean ing. Ad dr ess g leanin g is n ot w idely used, b ut in som e sit uat ions it can r educe t h e nu mb er of AARP estobt s t ain hat amu st beert ran sm st it tan ed. Readerrequ s w ill g reat un der ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tAARP o en su reOperation con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst s, pr ovidAddr in g ess a m Resolut or e r ealist ur e (of t he realw orh ld etare w orad k ing en vir onm ent s in The em Ap pleTalk ionicPrpict ot ocol AARP) m aps ardnw dr esses t o n et wor k w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease add resses. Wh en an App leTalk pr ot ocol h as dat a t o send, it passes t he n et w or k ad dr ess of t h e pr odu ct iv it y node an d im ov e eff help t het roeader m take e are in t elligent , cost - eff icient dest inat ion t o pr AARP. I t iciency, is t he job ofing AARP sup ply he hmor ar dw addr ess associat ed w it h decisions for t h eir net w ork s. t hat net w or k add ress. AARP ch eck s t he AMT t o see w h et h er t he n et w or k add r ess is alr ead y m apped t o a har dw ar e add ress. I f t he add r esses are alr eady m app ed , t he har dw ar e addr ess is passed t o t he inq uir in g App leTalk pr ot ocol, w hich uses it t o com m un icat e w it h t h e dest in at ion. I f t he addr esses ar e not m apped, AARP t ran sm it s a br oadcast r equest ing t hat t he n ode u sing t h e net w or k addr ess in

qu est ion supply it s har dw ar e addr ess. When t he requ est reaches t he node u sin g t h e net w or k add ress, t hat node replies w it h it s har dw ar e ad dr ess. I f no node ex ist s wit h t h e specif ied net w or k addr ess, no r esponse is sent . Aft er a specif ied nu mb er of ret r ies, AARP assum es t hat t he p rot ocol addr ess is not in use an d r et ur ns an err or t o t he in quir ing App leTalk pr ot ocol. I f a r esp onse is r eceived, t he h ard w are add ress is associat ed t o t h e net w or k addr ess in t he AMT. Th e har dw ar e add r ess t h en is passed t o t he in quir ing App leTalk pr ot ocol, w hich uses it t o com m un icat e w it h t h e dest in at ion n ode. •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Datagram Delivery Protocol Overview The Dat agr am Deliver y Pr ot ocol ( DDP) is t he pr im ar y net w or k layer r out ing p rot ocol in t h e App leTalk pr ot ocol suit e t hat pr ovides a best - ef for t con nect ion less d at agr am ser v ice bet w een App leTalk socket s. As w it h pr ot ocols such as TCP, no v ir t u al circuit or connect ion is est ablished •bet w een t w o Table of Content devices. The sf unct ion of guar ant eeing deliv er y inst ead is h andled by up per- lay er •pr ot ocols of tIhe ndex Ap pleTalk pr ot ocol suit e. These upp er - lay er pr ot ocols will b e discussed lat er in It his nt e rn w orer. k ing Te chnologie s H a ndbook , Four th Edit ion chetapt By Cisco Systems, Inc.

DDP per for m s t w o k ey fu nct ions: p ack et t r an sm ission and r eceipt . Pub lish er: Cisco Press Pub Datnsm e: Sepission tem ber 1of 1, 2pa 003ck e t s— Tra

DDP receiv es dat a fr om socket client s, cr eat es a DDP header byI SBN: u sin1-g58t 705 he -1 app 19 -2 rop r iat e dest in at ion ad dr ess, an d p asses t he packet t o t h e dat a lin k layer pr ot ocol. Pages: 11 28 Re cept ion of pa ck e t s— DDP receiv es fr am es fr om t h e dat a lin k layer , ex amines t h e DDP header t o find t h e dest inat ion addr ess, an d rou t es t he p ack et t o t he d est inat ion socket .

DDP m aint ains t he cable r ange of t he local net w or k and t h e net w ork addr ess of a r out er at t ached The u pdat edit ion of ev t heery b est - selling allin- one netitwion ork ting r ef erence p rov ofer s t o t he localednet w or k in AppleTalk node. I n add o t his inf or mat ion ides , Appcover leTalkage r out essent ial an d cu t t ingedg e t ech nologies. m ust m aint ain a rou t ing t able b y using t he Rout ing Table Main t en ance Pr ot ocol ( RTMP) . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

DDPnov Transmission Process ice t o ex pert .

New at chapt s include erag of ot imocol. por t ant opics VoI P andatEAP DDP oper es mer uch lik e anycov r out in ge pr Packt et s ar like e add ressed t he sour ce, are p assed t o t he dat a lin k layer , and ar e t r ansm it t ed t o t he d est inat ion . When DDP r eceives dat a f rom an Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age up per- lay er pr ot ocol, it d et er m ines w het her t he sou rce an d d est inat ion n odes are on t he sam e net w or k by ex am in ing t he n et w or k n um ber of t he d est inat ion ad dr ess. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I f t he d est inat ion net w or k nu mb er is w it hin t he cable r ang e of t he local net w or k , t he p acket is I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat encapsulat ed in a DDP header and is passed t o t he d at a link lay er for t r ansmission t o t he enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing dest inat ion node. I f t h e dest in at ion n et wor k n um ber is not w it hin t he cable r an ge of t he local t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing net w or k, t he p ack et is encapsulat ed in a DDP header an d is p assed t o t h e dat a lin k layer f or indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . t r ansm ission t o a rou t er. I n t erm ediat e r out er s use t h eir r ou t in g t ables t o f or war d t he packet Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, t ow ar d t he dest inat ion net w or k. When t he pack et r each es a r out er at t ached t o t he dest inat ion and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or k, t he p ack et is t r an sm it t ed t o t h e dest inat ion node. net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

AppleTalk Transport Layer The t ran sp ort lay er in App leTalk im plem en t s r eliable int er net w or k dat a- t ran sp ort ser v ices t h at ar e t r anspar ent t o up per lay er s. Tr anspor t lay er fu nct ions t y pically inclu de f low cont r ol, m ult iplexin g, v irt ual cir cu it m anagem ent , an d er r or check ing and r ecov ery . •

Table of Content s

• I ndex Five k ey im plem ent at ion s ex ist at t he t ran sp ort lay er of t he App leTalk p rot ocol suit e: I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Rou t ing Table Maint enan ce Prot ocol ( RTMP)

PubNam lish er:e Cisco PressPr ot ocol Binding

( NBP)

Pub Dat e: Sep tem ber 1 1, 2 003

App leTalk Updat e- Based Rout ing Pr ot ocol ( AURP) I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

App leTalk Tr ansact ion Pr ot ocol ( ATP) App leTalk Echo Pr ot ocol ( AEP) Each of t hese pr ot ocol im plement at ion s is add ressed br iefly in t he d iscussion s t hat f ollow . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Routing Table Maintenance Protocol Overview Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The Rou t inice g Table Maint nov t o ex pert . enan ce Pr ot ocol ( RTMP) is a t r anspor t lay er pr ot ocol in t he Ap pleTalk pr ot ocol suit e t hat est ablishes and m aint ains r ou t in g t ables in Ap pleTalk rou t er s. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP RTMP is based on t h e Rou t in g I n for m at ion Pr ot ocol ( RI P) ; as w it h RI P, RTMP u ses h op coun t as a r out ing merag et r ic. Hop is calcu lat ed as t h lik e nu mbical er ofn et rou t erksing or and ot herst or intage er m ed iat e nodes Cov e of cutcount t ing edge t echn ologies e opt wor t hr ou gh w hich a packet mu st pass t o t r av el fr om t he sou rce n et w or k t o t he d est inat ion n et w or k . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat RTMP Routing Tables enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing RTMP is .r espon le for est ablishing and m aint r out olog in g ties ables pleTalk r outireronm s. These indu st ry Lear n sib how t o incor por at e int er net w oraining kin g t echn in t ofor a Ap LAN/ WAN env ent . rCom out ing t ab les cont ain an ent r y for each net w or k t hat a p ack et can r each. plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Rou t er s p er iodically ex chang e r out ing inf orm at ion t o en su re t hat t he r out in g t ab le in each rou t er net w or kin g p rof essionals, r egar dless of ex pert ise. cont ains t he m ost cur r en t in for m at ion an d t hat t he inf or mat ion is consist en t acr oss t he int er netswwork Anain RTMP r outer in un g t der ab lest con t ainsoft hLAN e follow infnorm about Reader ill .obt a g reat an ding and ing WAN et wat orion k ing, p ar teach icu larof ly tthhee dest inat ion net w or ks k now n t o t he r out er : har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Net w ork cab le ran ge of t h e dest in at ion n et wor k Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, ance pr ovid g a mt oorteh er ealist icat pict e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Dist ininhops dest in ionurnet w ork pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr oduRou ct iv titery an e effticiency, help ing pordt im t h pr at ov leads o t he dest in at iont he n etr eader w or k m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Add ress of t he next - h op rou t er Cu rr ent st at e of t he r out in g- t ab le en t ry ( good, su sp ect , or bad) Figur e 38 - 8 illust r at es a t yp ical RTMP r out in g t able.

Figu r e 3 8 -8 . An RTM P Rout ing Ta ble Cont a in s I nf or m at ion Ab out Each De st in at ion N et w or k Know n t o t he Rout er

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Name Overview indu st ry .Binding Lear n how Protocol t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and Nam The speed, e Bin t hding is book Pr otisocol a com ( NBP) plet is e an a tdr anspor u p- t o- d t at layeer r efpr erot ence ocolt in o tthe he t Ap op pleTalk ics t hat pr are ot essen ocol suit t ialet o all tnet hatw m oraps kin gt hperof add essionals, resses ursed egaratdless low er of lay ex pert er s tise. o AppleTalk nam es. Sock et client s w it hin App leTalk nod es are kn own as Net w or k- Visible Ent it ies ( NVEs) . An NVE is a net w or k- addr essable Reader s wsuch ill obtas aina aprgint reat erv un of LAN ov and et w orwk or ing, ar t icuarlar t h e ed t o r esour ce, ser ice,der t hst atan isding accessible er WAN t he innt er net k . pNVEs e ly r eferr har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on by ch aract er st r in gs k now n as ent it y n am es. NVEs also hav e a zon e and v ariou s at t r ibut es, a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions k now n as ent it y t y pes, associat ed wit h t h em . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Covoerag Tw k ey er easons is also ext ex ist endf or ed using n ot only en t itt oy new nam es n etrwor at her k ing t h an concep ad drtesses s, but at also t het oupold per er ,layer legacy s. Fir st , systwem net or ks, add pr ovid resses in g ar am e assigned or e r ealistt ic o npict odes ur edyofnam t heically real- w anord,ldt hner et efor w or ke,ing chang en vir e onm r eg ularly ent s in . Ent w hich it y pr of essionals nam es pr ov ideoper a con at e. sist Tools ent way and for gu id u elines ser s t of or refopt er tim o net izing w or syst k r em esour per ces forand m ance ser vwices, ill incr such easeas a pr odu file serv ct iv erit. ySecon an d im d, pr using ov e eff nam iciency, es insthelp ead ing of addr t he resses eadert omref ake er mor t o reesou in t elligent rces and , cost ser v- eff ices icient decisions pr eser v es for t het ht reir anspar net wency ork s.of low er - lay er operat ion s t o end u ser s.

Name Binding Nam e binding is t he pr ocess of m ap ping NVE en t it y nam es w it h n et wor k ad dr esses. Each

App leTalk nod e m aps t h e nam es of it s ow n NVEs t o it s net w or k addr esses in a n ames t ab le. Th e com binat ion of all t he n am es t ables in all in t er net w or k nod es is kn ow n as t he nam es dir ect ory , w hich is a dist r ibut ed dat ab ase of all nam e- t o- addr ess m apping s. Name bindin g can occu r w hen a n ode is f irst st art ed up or d yn amically imm ediat ely befor e t h e nam ed ent it y is accessed. NBP p er f orm s t h e follow ing fou r fu nct ions: n am e looku p, nam e r ecognit ion, nam e confir m at ion, and nam e d elet ion. Nam e look up is used t o learn t h e net w or k addr ess of an NVE b ef ore t he ser v ices in t hat NVE are accessed. NBP ch eck s t h e nam es dir ect or y f or t he n ame- t o- ad dr ess • Table of Content s m appin g. Nam e r egist rat ion allow s a n ode t o cr eat e it s n ames t ab le. NBP confir m s t hat t he nam e • I ndex is not in use and t hen adds t he n ame- t o- ad dr ess m app ings t o t h e t able. Nam e confir m at ion is I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion used t o v er if y t hat a m app ing lear ned by u sing a nam e looku p is st ill accur at e. Nam e delet ion is By Cisco used t oSystems, r emov e Inc. an ent r y f rom t he nam es t ab le in such inst ances as w hen t he n ode is pow er ed off . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 AppleTalk Update-Based Routing Protocol Pages: 11 28

The App leTalk Upd at e- Based Rout ing Pr ot ocol ( AURP) is a t r anspor t lay er pr ot ocol in t he App leTalk pr ot ocol suit e t hat allow s t w o or m or e AppleTalk int er net w ork s t o be int er connect ed t hr ou gh a Tr ansm ission Cont r ol Pr ot ocol/ I nt er net Pr ot ocol ( TCP/ I P) net w or k t o f or m an App leTalk WAN. AURP en cap su lat es packet s in User Dat agr am Pr ot ocol ( UDP) h ead er s, allow ing tThe hemu pdat t o beedt ran spion ort of ed t the r anspar ent ly t hallrouinghone a TCP/ I Pork net w or k.erence An AURP lem ent at ion of has edit b est - selling net w ing r ef p rovimp ides cover age tessent w o com pon en t s: ext er ior r out er s and AURP t u nnels. ial an d cu t t ing- edg e t ech nologies. Ex t er ior rou t ers con nect a local App leTalk int er net w or k t o an AURP t unn el. Ex t er ior r out er s conv er t AppleTalk r out ing at ion and perpr for m encapsulat ionlev and Con cise ov er vdat iewas and of t echn ologinf iesorm essen t ialt ot oAURP n et wor k ing ofession als at all els,def rom encapsulat t r aff ic. An ex t er ior r out er f unct ions as an AppleTalk r out er in t he local nov iceion t o of exAppleTalk pert . net w or k and as an end node in t h e TCP/ I P n et wor k . Wh en ext er ior r out er s fir st at t ach t o an chapt include erag of immpor t antwtit opics likeex VoI and EAP AURPNew t u nnel, t h er eysex chang ecov rou t inge infor at ion h ot her t erPior r out ers. Th er eaft er , ex t er ior r out er s sen d r out in g in for m at ion on ly und er t he f ollow ing cir cu mst an ces: Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored bywor Cisco ems, ide leader w or king f or t he I n t er n et . When a n et k is Sy adst ded to w ororr ldw em oved fr om tin h enet r out ing t able I n t ernWhen et w or tkhe in gdist Tech nologies Hand , Four t h Ed it ion , is a com pr ehensive refer ence t hat ance t o a net w orbook k is ch anged enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing When a chan t o acep net k cau ses t h ean ext ior r out er t oinaccess w or k t echnologies. Mastge er tinhet he t erpmats,h con t s,w or t echn ologies, d er devices used t oday 'tshat netnet w ork ing gh it localt oint ern et wor r ater h er t hrgoug h t holog e t un orat hr ou gh t heenv t u nnel r at h er indu stt hr ry .ouLear n show incor por at ek int nett han w or kin t echn iesnel, in t o LAN/ WAN ir onm ent . t han t hitrou gh t an he dlocal in ed t er net w orerks on secur it y , st or age, opt ical net w or k in g, scalabilit y, Com plet ew h new u pdat chapt and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all An AURP f unct ions as a single, v irt at a link b et w een r em ot e App leTalk int er net w or ks. net w or kintgu nnel p rof essionals, r egar dless of exual pertd ise. Any n um ber of ph ysical nod es can exist in t h e pat h bet w een ex t er ior r out er s, but t h ese nod es ar e t r anspar t o t ha eg AppleTalk netstwan ording ks. Tw kindand s of WAN AURPn tet uw nnels exist : point - t ly o- point Reader s w ill ent obt ain reat er un der of oLAN or k ing, p ar t icu lar the thar un nels ipointand t unser nels. A point - ted o- point AURP ect sinfon t wion o exist er r out er dw arand e, prm otult ocols, v ices inv olv . Fu ndam entt u alnnel t echconn nology orlymat prior ov ided ons. A lt ip roint connect t hr ee orices, m or einext ering ior det r out er s. descr Two kipt in ion ds of m ult ipoin t ions a bmr uoad ang AURP e of intt un egrnel al sy st em ssand serv clud ailed s, rev iew quest t un nels also A fullyr eh conn ect ed mur et lt ipoint endit ables connect ior rst out er.s t o o en su re conexist cept. comp en sion and en t ion,t unn andelad ionalallr esou r cesed f orexfut er rt her udy sen packet t o one an ot . Wit h at opar t ially m u lt ipt s, oinbut t t unnel, e er or , m or e ex t er ior Covderag e is salso ext end edher n ot only new n etconnect wor k ingedconcep also t oonold legacy rsyst out em er ss,arpr e ovid aw are of esome, otpict all,urofe tof h et he ot her ext out Figur - 9 ent illust r atw eshich two in gonly a m or r ealistnic realwer orior ld nr et wer ors. k ing en evir38 onm s in App LANs con ed v iaand a pgu oint - t o- p oin t unn el. pr ofleTalk essionals oper atnect e. Tools id elines f ort AURP opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figu r e 3 8 -9 . An AURP Tun ne l Act s a s a Vir t ua l Lin k Be t w ee n Re m ot e Ne t w or k s

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

AURPPages: Encapsulation 11 28 When exchan ging r out ing inf orm at ion or d at a t h rou gh an AURP t un nel, AppleTalk pack et s mu st be con ver t ed f rom RTMP, ZI P, and ( in t h e Cisco im plem ent at ion ) Enhan ced I GRP t o AURP. Th e pack et s t hen are en cap su lat ed in User Dat ag ram Prot ocol ( UD P) header s f or t r anspor t acr oss t he TCP/ I P net w ork . Th e conv er sion an d encapsu lat ion ar e per for m ed b y ex t er ior r out ers, w h ich The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of r eceive Ap pleTalk rou t ing infor m at ion or dat a pack et s t hat mu st be sent t o a r em ot e Ap pleTalk essent ial an d cu t t ing- edg e t ech nologies. int er net w ork . Th e ext er ior r out er conv er t s t he pack et s t o AURP packet s, an d t hese p ack et s t h en ar e encapsulat ed in UDP h ead er s an d ar e sent int o t he t u nnel ( t h at is, t h e TCP/ I P n et w or k ) . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The TCP/ I P net k t r. eat s t he p acket s as n orm al UDP t r aff ic. The r emot e ex t er ior rou t er receiv es nov ice to w exor pert t he UDP pack et s and r em ov es t he UDP h ead er infor m at ion. Th e AURP p ack et s t hen ar e conv er t ed back New int o tchapt heir or for mcov at , erag w heteher aspor r out ant t in gt opics in for mlike at ion packet s. I f t he AppleTalk eriginal s include of im VoIorP dat anda EAP pack et s con t ain rou t ing infor m at ion, t he r eceivin g ex t erior r out er u pdat es it s rou t ing t ables accor Cov d in gly . I ef tof hecut pack et sedge conttain dat a destlik in ed f orical an nAppleTalk onort age h e local net w or k, t he erag t ing echn ologies e opt et wor k ingnode and st t r aff ic is sen t ou t t h e appr opr iat e in t er f ace. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat AppleTalk Protocol enables net w orTransaction kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing The an sact Pr ot ocol ATP) is w a or t r kin anspor t layolog er pr ot in ocol t he Ap pleTalk ot ocol induApp st ryleTalk . Lear Tr n how t oion incor por at e (int er net g t echn ies t o ain LAN/ WAN env irpr onm ent . suit e t h at h andles t r ansact ion s bet w een t w o AppleTalk sock et s. A t r ansact ion con sist s of Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, tand r ansact ion trhequest s an r an sact ses, e ex tch olved sock speed, is book is da tcom plet ion e anrespon d u p- t od atwehich r ef erarence o anged t he t opby icst he t hatinv are essen t ialett o all client s. net w or kin g p rof essionals, r egar dless of ex pert ise. The r equ est r ansact ionLAN requ est WAN ask ing inglar client Reader sw illing obtsock ain aetgclient reat ersends un derasttan ding of and n ett hat w or kt he ing,receiv p ar t icu ly t h per e for m som e act ionpr. ot Upon receiv est ,edt he s t hnology e requinf estor edmat action ion isanprdov r et ur nson har dw ar e, ocols, and ing ser vt he icesrequ inv olv . Fuclient ndamper entfor al m t ech ided tahe oregr mat inem a tsr ansact ionices, response. I n tdet r ansmit in g t ran sact eq uest s and b r appr oad ropr angiat e eofinf int alion sy st and serv in clud ing ailed tdescr ipt ion s,ion revriew quest ions rt oespon ATP perf or msr eh most of tand he im por anspor t layer inher g st udy . en suses, re con cept comp en sion r et enttant ion,t rand ad dit ional frunct esouions, r ces includ f or fu rt ackn ow ledg en t ext andend r eted r ansmission, and tseg ment at ion an derr,eassem Cov erag e is m also n ot only t o pack new et n etsequencing, wor k ing concep s, but also t o old legacy bly . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Sever al session layat ere.prTools ot ocols ovelines er ATP, ding t hesyst AppleTalk Session ASP) and pr of essionals oper andr un gu id f orinclu opt im izing em per for m ancePrwotillocol incr(ease t heodu Prin t erit yAccess ocol ( PAP) . These t w o tuhe pper - layerm App p rot ocols ,arcost e discussed pr ct iv an d imProt pr ov e eff iciency, help ing r eader ake leTalk mor e in t elligent - eff icient lat er in t his chapt decisions for ert h. eir net w ork s. Respond in g devices behav e dif ferent ly depending on w hich of t wo t y pes of t r ansact ion serv ices is being used: At - Least - Once ( ALO) or Ex act ly - On ce ( XO) t r ansact ions. ALO t r ansact ions ar e u sed w hen repet it ion of t he t ran sact ion r eq uest is t he sam e as ex ecut in g it once. I f a t r ansact ion r espon se is lost , t he sour ce r et ran sm it s it s r equ est . Th is does not adv er sely aff ect pr ot ocol oper at ions b ecause r epet it ion of t h e r eq uest is t he sam e as ex ecu t ing it once. XO t r ansact ion s

ar e used w h en r epet it ion of t h e t r ansact ion r equest m igh t ad ver sely af fect pr ot ocol op er at ions. Receiv ing dev ices k eep a list of ev er y r ecent ly r eceiv ed t r an sact ion so t hat du plicat e requ est s ar e not execut ed mor e t h an once.

AppleTalk Echo Protocol •The App leTalkTable Content Echoof Pr ot ocols ( AEP) is a t r anspor t lay er pr ot ocol in t he Ap pleTalk pr ot ocol suit e •t hat gener at es I ndex pack et s t hat t est t he r each abilit y of net w or k nodes. AEP can b e imp lem ent ed in Iany nt e rn et pleTalk w or k ing Te chnologie H a ndbook , Four th Edit ionned Ap node an d shas t he st at ically assig

sock et num b er 4 ( t h e Echoer socket ) .

By Cisco Systems, Inc.

To t est t he r each abilit y of a g iv en node, an AEP requ est pack et is passed t o t he D DP at t he sour ce. D DP ad dr esses t he p ack et ap pr opr iat ely , in dicat in g in t h e Typ e field t hat t he pack et is an Pub lish er: Cisco Press AEP r eq uest . When t he pack et is r eceiv ed by t he dest inat ion, DDP ex am ines t he Ty pe field an d Pub Dat e: Sep tem ber 1 1, 2 003 sees t h at it is an AEP r equest . I n t his p rocess, t he pack et is copied, chan ged t o an AEP reply ( b y I SBN: 58 705 chang ing a 1f ield in-1t19 he-2AEP packet ) , and r et u rn ed t o t he sour ce nod e. Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

AppleTalk Upper-Layer Protocols App leTalk im plement s ser v ices at t he session, p r esent at ion, and applicat ion lay er s of t he OSI m odel. Four k ey imp lem ent at ions at t h e session lay er are in clu ded in t h e AppleTalk pr ot ocol suit e. ( The session lay er est ablishes, man ages, and t erm inat es com m unicat ion session s bet w een •pr esent at ion Table Content lay erofen t it ies)s. •

I ndex

ICom nt e rnmetun w or k ing chnologie sconsist H a ndbook Four ion est s an d ser vice r espon ses t h at occur b et ween icat ionTesessions of, ser v th iceEdit r equ app licat ions locat ed in d if fer ent n et wor k d ev ices. Th ese r equest s and r esp onses are coor dinat ed By Cisco Systems, Inc. by p r ot ocols im plem en t ed at t he session lay er . lish er: Cisco Press ThePub session layer p rot ocol im p lem ent at ions su ppor t ed by App leTalk includ e t he Ap pleTalk D at a Pub tem(ber 1 1, 2,003 St r eamDat Pre:otSep ocol ADSP) Zon e I nfor m at ion Prot ocol ( ZI P) , AppleTalk Session Prot ocol ( ASP) , and I SBN: 158 705 -1 19 -2 ( PAP) . Pr int er Access Pr ot ocol Pages: 11 28

The Ap pleTalk Filing Pr ot ocol ( AFP) is im plement ed at t he p resen t at ion and applicat ion lay ers of t he AppleTalk pr ot ocol suit e. I n g en er al, t h e pr esent at ion lay er pr ov id es a v ariet y of coding an d conv er sion fun ct ion s t hat ar e applied t o ap plicat ion lay er d at a. The applicat ion lay er int er act s w it h sof t w ar e applicat ions ( w h ich ar e out side t h e scop e of t he OSI m odel) t hat im plement a com mu nicat in g com pon en t . App licat ion layer f unct ions t yp ically includ e ident ify ing The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of com mu nicat ion p art n er s, d et er m in ing resour ce av ailab ilit y , and sy nchr onizing comm u nicat ion . essent ial an d cu t t ing- edg e t ech nologies. Figur e 38 - 10 illust r at es how t he u pper lay er s of t h e AppleTalk pr ot ocol suit e m ap t o t he OSI m odel. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

FiguNew r e chapt 3 8 -1er0s. include App lecov Taerag lk Uppe - Lay Pr otlike ocols apEAP t o Th r ee Lay er s of e of imrpor t antert opics VoI PM and t h e O SI M ode l Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

AppleTalk Data Stream Protocol The App leTalk Dat a St r eam Pr ot ocol ( ADSP) is a session lay er pr ot ocol in t he Ap pleTalk pr ot ocol suit e t h at est ablish es and m ain t ains f ull- dup lex com m unicat ion bet w een t w o Ap pleTalk sock et s.

ADSP guar ant ees t hat dat a is cor rect ly seq uenced and t h at p ack et s ar e not dup licat ed. AD SP also im plement s a f low - cont rol mechanism t h at allow s a dest in at ion t o slow sour ce t ran sm ission s by r edu cing t h e size of t he adv er t ised r eceiv e w ind ow . ADSP r u ns dir ect ly on t op of t h e DDP.

Zone Information Protocol •The Z one I nf orm Table Content s atof ion Prot ocol ( Z I P) is a session lay er pr ot ocol in t he Ap pleTalk pr ot ocol su it e •t hat m aint ains I ndex n et wor k n um ber - t o- zone n am e map ping s in Ap pleTalk rou t er s. ZI P is u sed Ipr ntim e rnarily et w orbkying Te chnologie s Ha , Four th w Edit AppleTalk r out erndbook s. Ot her net or ion k nod es,

h ow ev er, use ZI P ser v ices at st ar t up t o main t ains a zone inf orm at ion t able ( ZI T) in each rou t er. ZI Ts are list s m aint ained by ZI P t hat m ap specif ic net w or k num b er s t o one or m or e zon e nam es. Each ZI T contPub ains a net w or k nu mb er - t o- zon e nam e m app in g for ev er y n et w or k in t he in t er net w or k . Figur e lish er: Cisco Press 38 - 11 illust r at es a b asic ZI T. choose t heir zone. By Cisco Systems, Inc. ZI P

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 3 8 -1 1 . Zone I nf or m a t ion Ta ble s Assist i n Zone I de nt if icat i on

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient AppleTalk decisions for t hSession eir net w orkProtocol s. The App leTalk Session Pr ot ocol ( ASP) is a session lay er pr ot ocol in t he Ap pleTalk pr ot ocol su it e t hat est ablish es an d main t ains sessions b et w een Ap pleTalk client s an d ser ver s. ASP allow s a client t o est ablish a session wit h a ser v er an d t o send com m and s t o t hat ser ver . Mu lt ip le client sessions t o a single ser ver can be m aint ained simu lt aneously . ASP uses m any of t he ser vices

pr ov ided b y low er - lay er pr ot ocols, such as ATP and NBP.

Printer Access Protocol Overview The Pr in t er Access Prot ocol ( PAP) is a session lay er pr ot ocol in t he Ap pleTalk pr ot ocol su it e t hat allow s client w ork st at ions t o est ablish connect ions w it h ser v er s, p art icular ly pr int er s. A session •bet w een a client Tablewofork Content s and a serv er is init iat ed wh en t h e w ork st at ion requ est s a session st at ion •w it h a par t icular I ndexserv er . PAP u ses t h e NBP t o lear n t he n et wor k ad dr ess of t h e r eq uest ed ser v er Iand nt e rn w oropens k ing Tea chnologie H a ndbook , Fourt he th Edit iont an d t he ser v er. Dat a is ex chang ed bet w een t heten connects ion bet w een clien client serv erInc. using t he ATP. When t he com m unicat ion is com plet e, PAP t er m inat es t he By Ciscoand Systems, connect ion. Ser ver s im plement in g PAP can sup por t m u lt ip le sim ult an eou s connect ions w it h client allows Pubs.lishThis er: Cisco Pressa pr int ser v er , for ex amp le, t o pr ocess jobs fr om sev er al dif ferent w or kst at ions at t h e same t im e. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

AppleTalk Filing Protocol The App leTalk Filing Prot ocol ( AFP) p er m it s App leTalk w or k st at ion s t o sh are files acr oss a net w or k. AFP per for m s fu nct ions at t he p resent at ion and applicat ion lay er s of t he Ap pleTalk pr ot ocol suit Thion is profottocol pr eser ves tallh e int r anspar ency t her ef n erence et w or k pb rov y allow u ser s tof o The u pdat ed e. edit he b est - selling one net w orkofing idesing cover age m anipu lat e rem ot ely st ored files in ex act ly t he sam e m anner as locally st or ed f iles. AFP uses t he essent ial an d cu t t ing- edg e t ech nologies. ser v ices p rov ided by t h e ASP, t he ATP, and t he AEP. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

AppleTalk Protocol Suite Figur e 38 - 12 illust r at es t he en t ir e Ap pleTalk pr ot ocol su it e and show s how it m aps t o t h e OSI r ef erence m odel. •

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Figu r e 3 8 -1 2 . The Apple Tal k Pr ot ocol Sui t e M a ps t o Ev e r y Lay er of t h e O SI M ode l

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

[ View full size im age]

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DDP Packet Format

The f ollow in g d escr ipt ions sum m ar ize t he f ield s associat ed w it h t he DDP packet s. This p ack et h as t w o f or m s:

Sh ort D D P p ack e t — The shor t f or m at is used for t ran sm ission s bet w een t w o n odes on t he sam e net w ork segm ent in a nonex t ended net w or k only . This f orm at is seldom used in new net w or ks. Ex t en de d D D P pa ck et — The ext en ded f or mat is used for t r ansm issions bet w een nodes w it h diff er ent net w or k num ber s ( in a n onext end ed n et w or k ) an d f or any t ran sm ission s in an ex t end ed net w or k . •

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Figur e 38 - 13 illust r at es t he for m at of t h e ex t end ed DDP pack et . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 3 8 -1 3 . An Ex t en de d D DP Pa ck e t Consist s of 1 3 Fie lds Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

[ View full size im age]

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The ex t ended packet fields illust r at ed in Fig ur e 25- 13 are su mm ar ized in t he discu ssion t hat nov ice t oDDP ex pert . follow s: New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP H operag couentof—cut Coun t he nt echn um ber of int lik er m ed iat e devices hr oug hw t he packet has Cov t ingt sedge ologies e opt ical n et wor kting and sthorich age passed . At t he sour ce, t his f ield is set t o 0 . Each int er mediat e node t h r ough w hich t he Aut h et pack ored passes by Cisco in creases Sy st ems, t he vwalue or ldw ofide t h is leader field biny net 1. Th w or e king m axim f orum t henum I n t er ber n etof . hop s is 15 . I n t ernLe et ng w ort h— k in gI n Tech dicat nologies es t he t Hand ot al len book gt h, , Four in b yt t hes, Ed itofion t he , isDDP a com packet pr ehensive . refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Che ck sum —er Cont t o det err or s. used I f no in checksum is w ork ing t echnologies. Mast t heains t er ma s,checksum con cep t s,value t echnused ologies, anect d devices t oday ' s net per for m ed , t h e bit s in t his op t ional f ield ar e set t o 0 . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, D e st i na ne tiswaork —plet I n dicat het o16d-at bite dest at iont on tet k ics n um berare . essen t ial t o all and speed, t h tision book com e anes d ut pr ef erinence hewor t op t hat net w or kin g p rof essionals, r egar dless of ex pert ise. Sou rce ne t w or k — I n dicat es t he 16 - bit sou rce n et w or k n um ber. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e e e, st ipr naot t ion node D —v ices I n dicat he. 8d est inat e I D.inf or mat ion is pr ov ided on har dwDar ocols, andI ser inv es olvted Fubit ndam ent al ion t echnod nology a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Sou rce node I D — I n dicat es t he 8- bit sour ce nod e I D. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag also end eedt — n ot only es t o new n et k ing t s, but also Dee st is i na t ionext sock I n dicat t he 8bitwor d est inatconcep ion socket n um bert.o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at and elines f or ce optsock im izing systber em. per for m ance w ill incr ease Sou rce sock e te. —Tools I n dicat es gu t heid8bit sour et n um pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions net Ty pefor — tIhneir dicat esw tork he s. up per - lay er pr ot ocol t o w hich t he inf orm at ion in t he D at a f ield belongs. D a t a— Cont ains dat a fr om an up per- lay er pr ot ocol.

Summary This chap t er has int rod uced y ou t o t h e AppleTalk pr ot ocol suit e. The AppleTalk pr ot ocol uses zones t o gr oup nod es or net w or ks in t o logical g rou ps. I n Ap pleTalk , d at a link lay er add resses ar e assig ned d yn am ically. •

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•App leTalk includes I ndex an add r ess- r esolut ion m et h od mu ch lik e TCP/ I P's ARP. The AppleTalk ver sion Iis ntcalled e rn et w or k ing Te chnologie s Hbr a ndbook , Four Edit ioner t he har dw ar e addr ess of a n ode. AARP. AARP uses oadcast s t othdiscov By Cisco Systems, Inc.

The p r im ar y net w or k lay er r ou t ing pr ot ocol in Ap pleTalk is t he D at agr am Deliver y Pr ot ocol ( DD P) . DDP pr ov id es a best - eff ort connect ionless dat agr am ser vice. Pub lish er: Cisco Press Dat Sep 1, 2 003en t at ions of t h e t r anspor t lay er in AppleTalk: RTMP, NBP, AURP, ATP, TherPub e ar ee:fiv e tem k eyberim1 plem and AEP. I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

Descr ibe an Ap pleTalk Zon e.

2:

I ndex ar e t he four main m edia- access imp lem ent at ions for t he App leTalk pr ot ocol? What

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Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : HowInc. ar e By Cisco Systems, 4:

n ode add resses assigned t o w or k st at ions?

What is t h e pr imar y n et w or k lay er rou t ing pr ot ocol used by App leTalk ?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

Nam e t he f ive key t r anspor t layer p rot ocols in AppleTalk.

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • ht t p: / / w w w . apple. com •

Table of Content s

•• ht t p: / / w w w I.ndex cisco.com / un iv er cd / cc/ t d / doc/ cisint w k / it o_d oc/ ap plet . ht m I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 39. IBM Systems Network Architecture Protocols • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

I nt r odu ce t he SNA p rot ocol, u sed pr im arily b y m ain fr am e syst em s and t er minals.

By Cisco Systems, Inc.

Descr ibe t he st r uct ur es and fu nct ioning of t his p rot ocol, f r om it s int r odu ct ion in t he ear ly f or m.

Pub19 lish70s er: Cisco t o it Press s cur r en t

Pub Dat e: Sep tem ber 1 1, 2 003

Descr BM-1peerI SBN: ibe 1- 58I705 19 -2 b ased net w or king . Pages: 11 28

Descr ibe t he basic inf or mat ion un it ( BI U) f orm at . Descr ibe t he pat h inf or mat ion u nit ( PI U) f or mat .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background I BM n et wor k ing t oday consist s of essent ially t w o separ at e ar chit ect u r es t hat b r anch, m or e or less, f rom a com m on or igin. Bef or e con t emp orar y n et wor k s exist ed, I BM' s Sy st em s Net w or k Ar ch it ect u re ( SNA) r uled t h e net w or kin g lan dscap e, so it of t en is r efer red t o as t r adit ional or •legacy SNA. Table of Content s •

I ndex

IWit nt eh rn tet w or k ingofTeper chnologie H a ndbook th Edit he r ise son al scom put er ,s,Four w ork st ation ions, an d clien t / ser v er com p ut ing, t he n eed for a peerbased net w or kin g st r at egy w as ad dr essed b y I BM w it h t he cr eat ion of Ad van ced Peer - t oBy Cisco Systems, Inc. Peer Net w or k in g ( APPN) and Ad van ced Prog r am- t o- Prog ram Com put in g ( APPC) . Pub lish er: Cisco Press Alt hou gh man y of t he legacy t echnolog ies associat ed w it h mainf r am e- b ased SNA hav e b een Pubht Datine:t o Sep tem berb1ased 1, 2 003 br oug APPNnet w or ks, r eal dif fer en ces ex ist . This chapt er d iscusses each br anch of I SBN: 158 705 -1 19 -2 ir onm en t , b eg in ning w it h legacy SNA en vir onm ent s an d f ollow in g w it h a t he I BM net w or kin g env discussion Pages: of 11 28 APPN. The ch apt er closes w it h sum mar ies of t he I BM basic- in for m at ion unit ( BI U) and pat h- inf orm at ion un it ( PI U) .

I BM- based rou t ing st rat egies ar e cover ed in a separ at e chap t er . Ref er t o Ch apt er 43 , " I BM Sy st em s Net w or k Archit ect ur e Rou t ing, " for d et ails ab out I BM r out ing p rot ocols. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Traditional SNA Environments SNA w as d ev eloped in t he 197 0s w it h an over all st ru ct ur e t hat par allels t h e OSI r efer en ce m odel. Wit h SNA, a m ainf r ame ru nning Ad van ced Com m unicat ion Facilit y/ Vir t ual Telecom m unicat ion Access Met h od ( ACF/ VTAM) ser ves as t h e hu b of an SNA n et wor k . ACF/ VTAM •is r esp onsib le Table of Content s for est ablishing all sessions an d f or act iv at in g and deact iv at ing r esou rces. I n t h is •env iron ment ,I ndex r esour ces are ex plicit ly pr ed ef ined, t h er eby elimin at ing t he r equir ement f or Ibr ntoadcast e rn et w or kt raf ing fic Te chnologie s H aizing ndbook , Four thov Edit an d m inim header er ion h ead . The u nder lying ar chit ect u r e and k ey com ponent s of tInc. rad it ion al SNA n et wor k ing ar e su m mar ized in t h e sect ions t h at f ollow. By Cisco Systems, Pub lish er: Cisco Press

IBM Architecture PubSNA Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

I BM SNA m odel Pages: 11 28 comp onent s m ap closely t o t he OSI refer ence m odel. The descrip t ion s t hat follow out line t h e role of each SNA comp onent in p rov iding conn ect iv it y am ong SNA ent it ies. D a t a li nk cont r ol ( D LC) — Defines sev er al pr ot ocols, in clu ding t he Syn ch ron ous Dat a Lin k Con t rol ( SDLC) p rot ocol for h ier ar ch ical com m unicat ion, and t he Tok en Ring Net w or k The ucom pdatmu ed nicat edit ion t he b est - selling all- in-u one ion of p rot ocol for LAN comm nicatnet ionwbork et wing eenr ef p erence eer s p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Pat h cont rol — Per f orm s m any OSI net w or k layer f unct ions, in clu ding r out ing and dat ag r am seg ment at ion an d r eassem bly ( SAR) Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov nsm ice t oission ex pertcon . t rol — Prov ides a reliable end- t o- en d conn ect ion ser v ice, as w ell as Tra encry pt in g and decr y pt ing serv ices New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP D a t a fl ow cont rol — Manages r equest an d response p rocessing , det erm ines w hose t u r n it Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age is t o com m un icat e, g rou ps m essages, and int er r upt s dat a flow on r eq uest Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . P re se nt a t i on se rv ices— Specif ies d at a- t r ansfor m at ion alg orit h m s t hat t r anslat e dat a fr om one for m at t o an ot her, coor d in at e r esour ce shar ing, and sy nch ron ize t r ansact ion I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat oper at ions enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Tra nsa ct i on se rv ice s— Prov ides app licat ion ser v ices in t he f or m of pr ogr am s t hat indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . im plem ent dist r ib ut ed pr ocessin g or m anagem en t ser vices Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and t h is book is a comprplet e an dfor u p-ittso-ph d at e r ef cont er ence o ter he. tTh opeics t hat are essen t ial t oisall SNA speed, d oes not d ef ine specific ot ocols ysical r ol tlay phy sical con t r ol layer net w or kin g p rof essionals, r egar dless of ex pert ise. assu m ed t o be im plement ed v ia ot her st an dar ds. Reader s w- ill obt ain reat er un der st anending LAN and WAN n et wm orap k ing, ar gener t icu laral ly ItSO h e OSI Figur e 39 1 illust r ataesg how t hese elem t s ofoft he I BM SNA m odel t o tphe har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on net w or kin g m od el. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, prrovid e r ealist pict ur e tofo t he w ornld Le n etve w orlsk ing vir onm in wel hich Figu e 3in 9 g-1a .mI or BM SNAic M a ps Al lrealSe ve of en t he O SIentMs od pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. A k ey const r uct d ef ined w it h in t h e over all SNA n et w or k m odel is t he pat h cont r ol net w ork , w hich is r esp onsib le for m ov ing inf orm at ion bet w een SNA n odes and facilit at ing int er net w ork Con ciseion ov beretv w iew s of t echnon olog ies essen t ial t oks. n etTh wor k ing pr ofession all lev els, en f rom com mu nicat een n odes diff erent net w or e pat h cont r ol n etals w orat k env ir onm t nov ice t o ex pert . uses fu nct ions p rov ided by t h e pat h cont r ol an d d at a link cont rol ( DLC) . The p at h con t r ol net w or k is a sub set of t he I BM t r anspor t n et w or k . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

IBM SNA Physical Entities

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Tr adit ional SNA phy sical en t it ies assum e on e of t he f ollow in g f our f or ms: host s, comm un icat ion s I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat cont r oller s, est ablish ment cont r oller s, and t er m in als. Host s in SNA cont rol all or par t of a enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing net w or k and t y pically pr ovide com pu t at ion, p r ogr am execut ion, dat abase access, dir ect or y t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing ser v ices, and n et w or k m anag em ent . ( An ex amp le of a h ost dev ice w it hin a t rad it ional SNA indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . env iron ment is an S/ 37 0 m ainf r ame. ) Comm u nicat ion s cont r oller s m anag e t he p hy sical n et w or k Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and cont r ol com m unicat ion lin ks. I n par t icular , comm un icat ion s cont r oller s—also called fr ont and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all end pr ocessors ( FEPs) —are relied u pon t o r out e dat a t hr ough a t r adit ional SNA net w ork . ( An net w or kin g p rof essionals, r egar dless of ex pert ise. exam ple of a comm u nicat ion s cont r oller is a 37 45. ) Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Est ablishm ent con t r oller s ar e com m only called clust er cont r oller s. These dev ices cont r ol inp ut har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on and out put oper at ions of at t ached devices, su ch as t er m inals. ( An ex am ple of an est ab lishm ent a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions cont r oller is a 31 74. ) Ter m inals, also r ef err ed t o as w or k st at ion s, pr ov id e t he u ser in t er f ace t o t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . t he net w ork . ( A t y pical exam ple w ou ld be a 32 70. Figur e 39 - 2 illust r at es each of t h ese ph ysical Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy ent it ies in t he cont ex t of a generalized SNA net w or k diagr am . ) syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figu r e 3 9 -2 . SNA Phy sica l Ent i t i es Can Assu m e On e of Fou r For m s

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

IBM SNA Data Link Control Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The SNA novdat icea tlink o excont pert rol . ( DLC) lay er supp ort s a nu m ber of m ed ia, each of w hich is d esign ed t o pr ov ide access t o devices and users w it h d if fer ing r eq uirem ent s. SNA- supp ort ed m edia t y pes include mainf r am annels, SDLC, andt ant Token Ringlike , am ong ot her m edia. New chapt eres ch include cov erag eX. of25, im por t opics VoI P and EAP A st anCov darerag d SNA aintfring amedge e chann el at t achmlik enet opt p rov ides a wor parkalleldat astchann e ofmcut t echn ologies ical n et ing and or ageel t hat uses direct m em or y access ( D MA) d at a- m ovem en t t echn iq ues. A m ainf ram e chan nel connect s I BM h ost s t o h ored st ems, or ldw ide leader inltnet king f orEach t he cab I n t er et . be up t o each Aut ot h er and by t o Cisco com mSy unicat ionswcont r ollers via mu iw irweorcables. lencan sev er al hun dr ed f eet in leng t h. A st andar d m ain fr am e chann el can t r ansf er d at a at a r at e of 3 t o I n 5t ern et w 4. Mbp s.or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Mast er tem he st er m s,ect con cep t s, t echnm ologies, used t oday ' s per net m w ork It echnologies. BM's Ent er pr ise Syst Conn ion ( ESCON) ainf raman e datdevices t ach ment envin iron ment it s ing indu er st ryt hr . Lear n how t o can incorcov porer at e or kin gdist t echn ologIies in t o a WANt renv onm high oug hpu t and grint eaterernet phwysical ances. n gener al,LAN/ ESCON ansfirer s d ent at a . at Com plet w it hsup new pdat -ed s on secur , st or age, ical netkilom w or k et in g, scalabilit y, 18 Mb pseand poran t s da upoint t o-chapt p oint er con nect ion , itryanging up t opt o sev eral er s, and speed, is book is a com anand d u pt o- d atdeistr an ef erces, ence t o t heutses op ics tand r ansfer s. Tot hallow h igher dat aplet r atees longer ESCON optt hat ical are f iberessen for itt ial s t o all kinmged p ium rof essionals, r egar dless of ex pert ise. net w or k . Reader ill obtw ain a g im reat er un der anSNA ding net of w LAN and n et w or kcom ing, mp unicat ar t icu lar ly an t h ed SDLC hsasw been idely plement edstin or ks t o WAN int er connect ions har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on est ablish ment cont r oller s, and t o m ove d at a v ia t elecom m un icat ions lin ks. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions X. netrew or kscept havcomp e longr eh been im plement ed t for intdit er connect ions. I n fgeneral, anstX. 25 . t o 25 en su con en sion and r et en ion,WAN and ad ional r esou r ces or fu rt her udy net or k eisissitalso uat ed een t wonly o SNA and t r eatconcep ed as tas,single linkt.oSNA plem en t s X. 25 Covwerag extbet endwed n ot t o nodes new n et worisk ing but also old erim , legacy as e access pr in otgocol, and odes sid er ed w adjacent t ooron e anot h eronm in tent h e scon of systt hem s, pr ovid a m or e rSNA ealistnic pict ar ur e con of t he realor ld n et w k ing en vir in twext hich X. 25essionals net w or ks. To at int con nect odes over anim X.izing 25 - based WAN, SNA requ ires D LCease pr ot ocol pr of oper e.erTools andSNA gu idnelines f or opt syst em per for m ance w ill incr capabilit hatd X. does not pr ov idhelp e. Sev ecialized DLC are ,em ploy t o fill t h e pr odu ct ivies it y t an im25 pr ov e eff iciency, ingeral t he sp r eader m ake morpreotinocols t elligent cost - effed icient gap , such for as t hhe decisions eirp hy netsical w orkserv s. ices h ead er , Qualified Logical Lin k Cont rol ( QLLC) , an d Enhan ced Log ical Link Cont r ol ( ELLC) . Tok en Rin g n et wor k s ar e t he pr im ar y SNA DLC m et h od for p rov iding m edia access t o LAN- b ased dev ices. Tok en Rin g, as sup por t ed b y I BM, is v irt u ally t he sam e as t h e I EEE 80 2. 5 link access pr ot ocol r un ning un der I EEE 80 2. 2 Logical Lin k Cont rol Typ e 2 ( LLC2) .

I n addit ion t o t he basic suit e of m edia t y pes, I BM added su ppor t for sever al ot h er wid ely im plem ent ed m ed ia, including I EEE 8 02. 3/ Et her net , Fiber Dist r ib ut ed Dat a I n t er f ace ( FDD I ) , and Fram e Relay . Figur e 39 - 3 illust r at es how t he v ar iou s m ed ia gener ally fit in t o an SNA net w ork .

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Table of Content s

FiguI ndex r e 3 9 -3 . SNA Ha s Ev ol ve d t o Sup por t a V ar i et y of M edi a

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

IBM Network Addressable Units

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . SNA d ef ines t hr ee essent ial n et w or k ad dr essable un it s ( NAUs) : logical unit s, p hy sical u nit s, and I n t ern or kt s. in gEach Techplay nologies Hand Four Ed ion , is aconn comect pr ions ehensive refersy ence t hatin an cont r oletpwoin s an im por book t an t r, ole int hest abit lishing b et ween st ems enables net SNA n et w orw k .or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ryunit . Lear n howf un t octincor porend at e- int er net w or kin ies innet t o waorLAN/ WAN env ent . Logical s ( LUs) ion as user access porgt st echn int o olog an SNA k. LUs pr ov idireonm users Com e w itt oh nnew ankdr uesou pdatrces, ed chapt s onmsecur age, opt icalofnet or k at in g, w it h plet access et w or and er t hey anag it e yt ,hest tor ran sm ission infworm ionscalabilit bet w eeny,end and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all users. net w or kin g p rof essionals, r egar dless of ex pert ise. Phy sical un it s ( PUs) ar e u sed t o mon it or and cont r ol at t ached net w or k link s and ot her n et w or k Reader s w associat ill obt aineda w g reat untder st annode. ding of LAN WAN n et lar access ly t h e r esour ces it h aerpar icu lar PUs ar eand im plement edw or onk ing, host sp ar byt icu SNA har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is m et hods, such as t he vir t ual t elecomm u nicat ion access m et hod ( VTAM) . PUs also ar pr e ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew im plem ent ed w it hin com m un icat ions con t r oller s by n et wor k cont r ol pr ogr am s ( NCPs) . quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag Con t rol peoin is talso s ( CPs) ext end m an edage n otSNA onlyn todes o new and n ett heir wor kring esouconcep rces. CPs t s, but g enalso er ally t o ar old e er dif, ferent legacyiat ed syst fr omem PUs s, pr in ovid t hatinCPs g a dmetoreremr ealist ine w ic hich pictact ur e ionofs tm heust realb e wt ak or en ld ,n w ethile w or kPUs ing cau en vir seonm act ion entss tin o occur w hich. pr ofex An essionals am ple ofoper a CP at is e. tTools he SNA and sygu st em id elines ser vices f or opt cont imr ol izing poinsyst t ( SSCP) em per . for An m SSCP ancecan w ill be incr t hease e CP rpresiding odu ct ivinit ya an PUd 5imn pr ode ov or e eff aniciency, SSCP as help iming plem t he entr eader ed un der m ake an mor SNAe access in t elligent m et,hod, cost -such eff icient as VTAM. decisions for t h eir net w ork s.

IBM SNA Nodes Tr adit ional SNA nodes b elon g t o one of t w o cat eg ories: sub area nodes and per ipher al nod es. SNA sub area nodes pr ov ide all n et w or k serv ices, in clud ing int erm ediat e n ode r out ing an d

add ress m appin g b et ween local an d net w ork - w ide ad dr esses. No r elat ionship exist s b et w een SNA n ode t y pes and act ual phy sical devices. Two subar ea n odes are of par t icu lar int erest : node t y pe 4 and n ode t y pe 5 . Node t yp e 4 ( T4) u su ally is con t ained w it h in a com m un icat ion s con t r oller , such as a 3 745 . An exam ple of a T4 node is an NCP, w hich r out es d at a an d con t rols f low bet w een a fr ont - en d pr ocessor and ot h er net w ork resour ces. •

of Content s Node t yp e 5 Table ( T5) u su ally is con t ained in a host , such as an S/ 370 m ainf ram e. An ex am ple of a •T5 node is t he I ndex VTAM r esident w it hin an I BM m ain fr am e. A VTAM con t r ols t he logical f low of dat a It hr nt eou rn et ingwTe sH a ndbook th Edit ghw or a knet orchnologie k , pr ov id es t he int, Four er face b etion w een ap plicat ion sub sy st ems and a net w or k , and pr ot By Cisco ect sSystems, app licatInc. ion su bsyst em s fr om unaut hor ized access.

SNAPub p lish er iph er al n odes use only local ad dr essing and comm un icat e w it h ot h er nodes t h rou gh er: Cisco Press subar ea n odes. Node t y pe 2 ( T2) is gener ally t he p er iph er al n ode t y pe of int er est , alt houg h SNA Pub Dat e: Sep tem ber 1 1, 2 003 does specif y a node t yp e 1 p er iph er al n ode. T2 t y pically r esid es in int elligent t er m inals ( such as 1- 58 705 -1 19 -2 a 3 270I)SBN: or est ablishm ent con t roller s ( such as a 31 74) . Node Ty pe 1 ( T1) is now obsolet e, b ut 11 28 w hen Pages: imp lem ent ed, it r esided in u nint ellig en t t er m in als. Figur e 39 - 4 illust r at es t he var ious SNA nod es and t heir r elat ionship s t o each ot her.

Figu r e 3ed9 edit -4 . ion Peof r iph a l- selling Nodealls Com mnet u ni cating e w h O t hp rov er ides Node s Thr ou gh The u pdat t he er b est in- one w ork r efiterence cover age of essent ial an d cu t t ing- edg e t ech nologies. Suba r ea N odes Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IBM Peer-Based Networking Ch anges in net w or king and com m unicat ions r equir ement s cau sed I BM t o evolv e ( and g en er ally ov er hau l) m any of t he basic design ch ar act er ist ics of SNA. Th e emer gence of peer- b ased net w or kin g ent it ies ( such as r out er s) r esult ed in a nu mb er of sig nificant ch anges in SNA. •I nt er net w orkTable of Content s p eer s hing es on sever al I BM- d ev elop ed n et w or k ing com pon en t s. ing am ong SNA •

I ndex

IAdv nt e rn et w or Peer k ing Te chnologie s Hw a ndbook th Edit ionr esent s I BM' s second - generat ion SNA. I n creat ing anced - t oPeer Net or k in g, Four ( APPN) r ep APPN, I BM mov ed SNA fr om a hierar chical, m ainfr am e- cent ric env ir onm en t t o a p eer - based By Cisco Systems, Inc. net w or kin g env ir onm en t . At t he h ear t of APPN is an I BM ar chit ect ur e t hat supp ort s peer - based com mu nicat ion s, dir ect or y serv ices, an d r out in g bet w een t w o or m or e APPC syst em s t hat ar e not Pub lish er: Cisco Press dir ect ly at t ach ed . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 APPN Components

I n addit ion t o t he APPN env ir onm en t , peer - based SNA net w ork ing specif ies t hr ee ad dit ional key net w or kin g concept s: log ical unit s ( LUs) , Ad van ced Pr ogr am - t o- Pr ogr am Com pu t ing ( APPC) , and nod e t y pe 2. 1 . Each plays an im por t an t r ole in t he est ablish m en t of com mu nicat ion am on g SNA The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of peers w it h in t he cont ex t of an SNA- based p eer int er net w or k. essent ial an d cu t t ing- edg e t ech nologies. Log ical Unit ( LU) 6. 2 g over ns p eer - t o- peer com mu nicat ions in an SNA en vir onm ent . I n add it ion, LU 6 . 2 sup por t s gener al com m unicat ion b et ween pr ogr am s in a dist r ibut ed pr ocessing Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom env iron ment and bet w een b ot h sim ilar and dissim ilar nod e t y pes. APPC enab les SNA applicat ions nov ice t o ex pert . t o com m un icat e d irect ly w it h p eer SNA applicat ions, and it pr ovid es a set of pr ogr am m in g conv en t ions an derpsrot ocols tcov h at erag im plem LU t6. 2. tNod e tlike y peVoI 2. 1s ( T2. EAP 1) ar e logical en t it ies t hat New chapt include e of en imt por ant opics P and per m it dir ect comm u nicat ion am ong per ipher al nod es cap able of supp ort in g T2 . 1. Th e T2. 1 ent it yCov f acilit at eesofpoin t o- point nicat ions ovidin g d kating a t rand an spstort supp ort for peer erag cut tt -ing edge tcom echnmu ologies lik e by optpr ical n et wor or age level com m unicat ions sup por t ed b y APPC. I n addit ion , a T2 .1 cont ain s a p er ipher al n ode cont r ol point Aut ( PNCP) comb ines he t rad ion al ionsinofnet a phy ( PU) a . con t r ol point h oredt hat by Cisco Sy st tems, w orit ldw idef unct leader w or sical king funit or t he I n tand er n et ( CP) . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing IBM APPN Node Types indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Under APPN,t hpiseer - based unicat occur am ell-t d ined node pes. tThese and speed, book is a com comm plet e anion d u pt o- dsat e rong ef er sever ence al to w t he opefics t hat aret yessen ial t o all nod es can be br oken dow n int o t hr ee basic t yp es: lowen t ry nodes ( LENs) , end nodes ( ENs) , and net w or kin g p rof essionals, r egar dless of ex pert ise. net w or k nod es ( NNs) . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e The lowry otnet w orkand ( LEN) ode inv is aolv pred e- .APPN era ent peero- peer node. A mat LENion node p ar icipaton es har dw arent e, pr ocols, ser vn ices Fu ndam al tt ech nology inf or is pr ovtided in bAPPN weorof kinint g egr b y al t aksy ing advs ant ofices, ser vices pring ov iddet edailed b y andescr ad jacent netrev w ork NN) . a r oad rnet ang st em andage serv in clud ipt ion s, iew node quest( ions of con t h e cept LEN comp nod e rman esour ces and but does not est ablish a CPo-rtCP tThe o enCP su re eh enages sion local and rret en t ion, ad dit ional r esou r ces f or tfu hersession st udy . w it h t he erag adjacent NN. ext Befend or eed a session st ar tn, et session parconcep t ner s m defin LEN n ode, Cov e is also n ot onlycan t o new wor k ing t s,ust butb ealso t oed oldf or er ,alegacy and em t h es,LEN node st or bee defined s eser ovid NN. en vir onm ent s in w hich syst pr ovid in gmu am r ealist ic for pictitur ofvicet he pr realwin orgldadjacent n et w or k ing pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease An endctnode EN) con aineseff a iciency, su bset of fu lling APPN or tm . An d node accesses t he -neff eticient w or k pr odu iv it y (an d im prtov help t he supp r eader akeenmor e in t elligent , cost tdecisions hr ou gh an ad jacent NN and uses t he rou t ing ser v ices of t he sam e ad jacen t NN. To comm u nicat e for t h eir net w ork s. on a n et w or k , an EN est ablishes a CP- t o- CP session w it h an adjacent NN and u ses t h e CP- t o- CP session t o r egist er r esour ces, r equest dir ect ory ser vices, and requ est r out ing inf orm at ion. Anet w or k nod e ( NN) con t ain s fu ll APPN f unct ionalit y . Th e CP in an NN m anag es t he r esou rces of t he NN, as w ell as t he at t ach ed ENs and LEN nodes. I n addit ion, t he CP in an NN est ab lishes CPt o- CP sessions w it h adj acent ENs an d NNs, an d m aint ain s t he n et wor k t opology and d ir ect ory

dat ab ases cr eat ed and u pdat ed by g at herin g in for m at ion d yn am ically fr om ad jacent NNs and ENs. Figur e 39 - 5 illust r at es w her e each of t hese peer t y pes m ig ht be f ound in a g en er alized APPN env iron ment .

• •

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Figu rI ndex e 3 9 -5 . APPN Supp or t s Se v er a l W e ll - De fi ne d N ode Typ es

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

IBM I n t ern APPN et w or k in Services g Tech nologies Hand book , Four t h

Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. erf all t heint t ero mfou s, rcon cep al t s,cat t echn ologies, anigur d devices used ins,t oday ' s net, wan ork Basic APPN serMast v ices gener eg ories: conf at ion, dir ect or t opology d ing st ryand . Lear n how ser t o vincor at e is intsu erm net w or kin gint echn ologions ies in o af ollow. LAN/ WAN env ir onm ent . rindu out ing session ices.por Each mar ized t h e sect t htat Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g pConfiguration rof essionals, r egar dless of ex pert ise. IBM APPN Services Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e APPN ion ser v ices e r esp forndam act ivent at ing ionsinf t oort mat he APPN w ork . on har dwconf ar e, igur pr otatocols, and serar v ices invonsib olv edle. Fu al tconnect ech nology ion isnet pr ov ided Con nect ion act ivat ion inv olv es est ablishing a conn ect ion, est ab lishing a session , and select ing an a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions adj acen cy op t ion. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy The con nect phase of conn ect ion act ivat ion enables t he in it ial est ab lishm ent of comm un icat ion s syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich bet w een nod es. Th is init ial com mu nicat ion in volv es ex chang ing ch aract er ist ics and est ablishing pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease r oles, such as pr im ar y ver sus second ar y. Connect ion est ablishm ent is accom plished b y t he pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient t r ansm ission of ex chang e ident ificat ion t y pe 3 ( XI D3) fr am es bet w een nodes. decisions for t h eir net w ork s. Du ring session est ab lishm ent , CP- t o- CP sessions ar e est ab lish ed w it h an ad jacent EN or NN. Minim ally, each node mu st est ablish at least one pair of CP- t o- CP session s w it h one adj acen t nod e. An EN can est ablish a m ax im u m of one p air of CP- t o- CP sessions bu t can be at t ach ed t o m or e t han one NN. Bet w een NNs, p air s of CP- t o- CP session s w it h all adjacent nodes or a subset of adj acent nod es can be est ablished. Th e m inim um r equir em ent is a sing le pair of sessions t o

one ad jacent NN, w hich ensur es pr oper t op ology up dat ing . Adj acency am ong APPN nodes is d et er m in ed b y using CP- t o- CP sessions. Tw o conf igur able opt ion s ar e available f or det er min in g node ad jacency. A nod e can b e specif ied as adj acen t t o a single n ode, or as logically adj acent t o ev ery p ossible ad jacent node. Select ing an adj acency opt ion f or a specific sit uat ion depends on a giv en n et w or k 's conn ect iv it y r eq uir em ent s. Th e r ed uct ion in CP- t o- CP session s associat ed w it h single- node adjacency can r edu ce n et wor k ov er head associat ed wit h t op olog y up dat es, as w ell as t he n um ber of bu ff er s r equir ed t o • Table of Content s dist r ibut e t opology u pdat es. Redu cin g t h e nu mb er of adjacent nodes, how ev er , also incr eases • I ndex t he t ime requ ir ed t o sy nchr onize r out er s. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

IBM APPN Directory Services Pub lish er: Cisco Press PubdDat e: Sep ber 1 1, 2 ar 003e int end ed t o help n et w or k dev ices locat e serv ice pr ovid er s. These APPN irect or ytem ser v ices I SBN: 158 705 -1 19 -2 ser v ices ar e essent ial t o est ablish ing a session bet w een end user s. Dir ect or y ser vices in APPN call forPages: each11NN 28 t o m ain t ain a dir ect or y of local r esou rces and a net w ork d irect or y t hat associat e end users w it h NNs pr ov iding ser v ice. A dist r ib ut ed dir ect or y ser v ice t hen is for m ed f rom t he collect ion of in div id ual NN net w ork direct or ies. Th is sect ion su mm ar izes t he n at ur e of APPN dat ab ases, nod e- direct or y ser v ice h andling , and t h e r ole of a cen t r alized dir ect or y serv ice.

The local an d n et wor k d irect or y dat ab ases supp or t t h ree serv ice- ent r y t yp es: con figur ed en t r ies, The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of r eg ist er ed ent r ies, and cach ed ent r ies. Conf ig ur ed d at abase ent r ies usually ar e local low - ent r y essent ial an d cu t t ing- edg e t ech nologies. net w or k nod es t hat m u st be conf igur ed becau se no CP- t o- CP session can be est ablish ed ov er w hich t o ex ch ange in for m at ion. Ot h er nodes m igh t be con figu red t o r edu ce b road cast t r aff ic, w hichCon is generat edv iew as par t heolog d iscov y p rocess. ist er ed pr entofession r ies ar eals local r esour ce ent r ies cise ov er s oft tof echn ies er essen t ial t o nReg et wor k ing at all lev els, f rom abou tnov w hich an en d n ode h as infor m ed it s associat ed net w or k nod e ser v er w hen CPt oCP ice t o ex pert . sessions ar e est ablish ed . A r egist ered en t r y is added by an NN t o it s local d ir ect ory . Cach ed dat abNew ase en t r ieserar dir ect ory en t ries eatpor edt ant as session requVoI estPs and an d EAP r eceiv ed b y an NN. The chapt s einclude cov erag e ofcrim t opics like t ot al num ber of cached ent ries per m it t ed can be cont r olled t h rou gh user config ur at ions t o m anage Covmem erag eorof y rcut eq uirem t ing edge ent s.t echn ologies lik e opt ical n et wor k ing and st or age The end Aut-hnod ored e dir byect Cisco or y ser Sy st v ice ems, negot w oriat ldwion ideprleader ocess in invnet olves w orsever king falorstt he eps.I nAn t er nEN et .f ir st sen ds a LOCATE requ est t o t h e NN p rov iding net w or k ser v ices. The local an d net w ork direct or y I n t ern et w ornkex intgare Tech nologies bookine , Four t hher Ed itt he iond, est is ainat com ehensive refer ence hat dat ab ases sear ch ed t Hand o det erm wh et ionprend user is alr ead y tkn ow n. I f net or kin p r ofessionals derstdand im plem en t cont por tart oy int er net tenables he dest in atwion endg user is k now n,t oa un single ir ectan edd LOCATE r eq uest em is sen ensur e itwsork curing r en t t echnologies. er t he t er m s, con cep tiss, not t echn ologies, anex d ist devices used in t oday ' s net w ork aing av ailab ilit y . I f Mast t he dest in at ion end user f ound in t he ing d at abases, t he NN sends indu st ry .requ Learest n how incor por w orwkin g her t echn olog iesinat in tion o a en LAN/ WANisenv ir onm ent . LOCATE t o adt ojacent ENsatteo int d eterernet m ine het t he dest d user a local plet h new d ion u pdat secur it ys , astbor age, optLOCATE ical net wr or k in g, tscalabilit y, t rCom esour ce.e Iwf itt he d estan inat is ed notchapt local,ertsheonNN send road cast equest o all ad jacen and speed, t h is book a com plet dw u po- A d at r ef er ence t o t back he t opt oicst he t hat are essen t ial t o all NNs f or pr opagat ion t is h rou ghou t t he ean net ortk. meessage is sent or iginat in g NN net w oring kin gt hpat roft essionals, egarisdless pertt hise. indicat h e dest in atr ion foun of d wex h en e NN pr ov iding net w or k ser v ices f or t he dest inat ion en d user locat es t h e en d- user r esou rce. Fin ally , b ot h orig in an d d est inat ion NNs Reader ill for obt a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e cach e t shew in main at ion. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a r oad of int egr al sy st em sarand servled ices, det ion iewnode quest ionss Dirb ect or yr ang serveices for LEN n odes e hand by in a clud pr oxing y ser v ailed ice pr descr ocess.iptFir sts, , arev LEN send taoben su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ind session ( BI ND) r eq uest for at t ached r esou r ces. This cont r ast s w it h t he LOCATE r equest Cov e is also ext end onlyortyo ser new n et wor ingmconcep s, butpralso o old er , legacy sen terag b y ENs. To receiv e ed anyn ot direct v ices, an kNN ust pr tovide oxy t ser vices for a LEN syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent srequ in west hich nod e. When a pr ox y ser v ice NN is link ed t o t he LEN n ode, t he NN br oadcast s LOCATE s as pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease needed f or t h e LEN nod e. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions A cent r al dfor irect t h eir or y net serwv ork ice s. u su ally ex ist s w it hin an ACF/ VTAM and usually is im plem en t ed t o help m inim ize LOCATE b road cast s. Th is kind of d at abase can b e used t o m aint ain a cent r ally locat ed dir ect or y f or an ent ir e net w or k becau se it cont ains con figu red, regist ered, and cach ed ent r ies. Under a cent r alized d irect or y ser v ice p rocess, an NN send s a d irect ed LOCATE br oadcast t o t he cen t r al dir ect or y serv er , w hich t hen search es t he cen t r al dat ab ase and br oadcast s w hen necessar y.

IBM APPN Topology and Routing Services I n an APPN net w ork t opology , n et w or k nod es are con nect ed by t ran sm ission gr oup s ( TGs) . Each TG con sist s of a sin gle link , and all NNs m aint ain a n et wor k t opology dat abase t hat cont ains a com plet e pict ur e of all NNs and TGs in t h e net w or k. Tran sm ission gr oup s ar e discussed in Ch apt er 43 . •

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•A n et wor k 's tIopology ndex d at abase is up dat ed by inf orm at ion r eceived in a t opolog y dat ab ase u pdat e I( nt e rn etm w or k ing e. Te chnologie s H am ndbook , Fourflow th Edit ion TDU) essag These TDU essages over

CP- t o- CP session s w henever a ch ange occur s in t heCisco net w ork , such By Systems, Inc.as w hen a n ode or link b ecom es act ive or in act iv e, w hen con gest ion occur s, or w hen resour ces are lim it ed. Pub lish er: Cisco Press

The n et wor k t opology dat abase cont ains inf or m at ion u sed w hen calculat ing r out es w it h a Pub Dat e: Sep tem ber 1 1, 2 003 par t icular class of ser vice ( CoS) . This inf or mat ion includ es NN and TG con nect iv it y and st at us, 58 705 -1 19 -2 erist ics, su ch as TG capacit y. and NNI SBN: an d1-TG char act Pages: 11 28

APPN's rou t ing ser v ices f unct ion uses in for m at ion fr om dir ect or y an d t opology d at abases t o det er min e a r out e based on CoS. Rout e d et er m in at ion st ar t s w h en an end node fir st r eceives a session r equ est fr om a log ical unit . A LOCATE requ est is sent fr om t he EN t o it s NN t o requ est dest inat ion infor m at ion and t o ob t ain a r out e t h r ough t he net w ork . Th e NN t h en ident if ies t h e pr oper t ies ed associat h tbhe est ed of ser t ified pprrov opert ar e age comof par ed The u pdat edit ionedofwtithe estrequ - selling all-lev in-elone netvwice. ork The ing rid efen erence idesies cover tessent o pr opert ies of each TG and NN in t h e net w or k, and all r out es t hat m eet t he specified cr it eria ial an d cu t t ing- edg e t ech nologies. ar e cach ed as ap plicab le. Each EN, NN, and TG in t he net w or k is assig ned a w eig ht based on CoS pr oper t ies, su ch as capacit y , cost , secur it y , and delay . Pr opert ies also can be u ser - defined. Finally, a cise leastov - cost p atshofist det erm ined t ot aling eigkht s on t he pat hs meet t h e f rom Con er v iew echn olog ies by essen t ial t ot hn eetw wor ing pr ofession alst hat at all lev els, r out ing it ert o ia.ex pert . novcrice New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

IBM APPN Session Services

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

FollowAut ingh ored r out eby estCisco ablishm ent , t h ew APPN sessionestinablishm t p rocess in g on t h e Sy st ems, or ldw ide leader net w oren king f or t hevar I n ies t er ndepend et . nod e t y pe. I f t he or iginat in g end user is at t ached t o an EN, a LOCATE r ep ly con t aining t he locat ion e gdest inat ion andHand r out e is r et ur ned o tithion e or ig inat ingprEN by t h e NN acen t t o t he I n t ern et wofort kh in Tech nologies book , Four t h tEd , is a com ehensive referadj ence t hat dest inat ion EN. Th ge porr ofessionals ig inat ing ENt ot hen sendand s a BI a session e. I ar f or in g, t h eing end enables net w or kin un derst anND d imon plem en t contr out em por y iginat int er net w ork user is at t ached t o er a LEN send BI ND t o it s adjacent NN.used The ad vering ts t echnologies. Mast t he t nod er mes,t hat con cep t s,s at echn ologies, an d devices in jacent t oday ' sNN netcon w ork tindu he LEN ND nt ohow APPN ND,por and a BI ong tthechn e session p at st ry .BILear t o BI incor at esends int er net wND or kin olog ies inh. t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, A BI ND is a tspecific r equest m essag ant ot BI ND carr iest ot he and speed, h is bookt yispea of com plet e an d u p- teo-sen d attef rom r ef erone enceLU t o t tohe opher ics LU. t hat Aare essen t ial all rnet outweorbkin eingg purof sedessionals, for a session. I t sp ecifies NNs an d TGs, a un ique session ident ifier f or each TG, r egar dless of ex pert ise. t he t ran smission p rior it y f or t he session, and w in dow in for m at ion t o supp ort adap t ive pacin g t o limit t r aff t he or k .er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Reader s wicillon obt ainn aetgwreat har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Basic Information Unit Format I BM SNA NAUs em ploy b asic inf or mat ion u nit s ( BI Us) t o ex ch ange requ est s an d r esponses. Figur e 39 - 6 illust r at es t he BI U f or mat . •

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•

I ndex

Figu r e 3 9 -6 . A Ba si c I n for m a t i on U ni t ( BI U) Can Be Ei t he r a Req ue st or a Re sponse

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing BIU FieldsMast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t echnologies. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . The ollow initghf ield ion sedsum m arize t hesecur contitent ofort he BIopt U, as e 39 y, - 6. Comfplet ew newdescript an d u pdat chapt er s on y , st age, icalillust net wr at ored k inin g, Figur scalabilit and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Re que st h ea de r— I d en t ifies t he t yp e of dat a in t h e associat ed r equ est unit s. This h ead er prsovwides infor ion about t hest for m at of h e dat a and rot ocols f orlar t he . Reader ill obt ain ma at g reat er un der an ding of tLAN and WANspecif n et wies or kping, p ar t icu ly tsession he u se r and equ est m .atFu ion. har dwOn ar ly e, NAUs pr ot ocols, ser vheader ices invinfor olv ed ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Rere que stcept u nitcomp — Cont eit hand er en user a oradSNA comrm ands. Endser d at a is sent in t o en su con r ehains en sion r etd-en t ion,dat and dit ional esou r ces f or ufu rt her st udy . dat a r eq uest un it s. SNA comm an ds ar e sen t in comm an d r equest u nit s t h at cont r ol t he Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy net orovid k and m at b et ww een syst em s,wpr in gcont a main or einfor r ealist icion pictex urchan e of ged t he realor ldend n etuwser or ks.ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Re sponse he ad er — I d en t ifies t he t yp e of dat a associat ed w it h t he r esponse un it . The pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient r eq uest / response in dicat or bit dist in guishes a response h ead er f r om a r equ est header. A decisions for t h eir net w ork s. r eceivin g NAU ind icat es w h et h er t he r esp onse being r et u rn ed t o t he r equ est send er is posit iv e or negat iv e by set t ing t h e respon se t yp e indicat or ( RTI ) bit in t h e r espon se h ead er . Re sponse uni t — Cont ains infor m at ion about t he r equ est in dicat ing eit h er a posit iv e or negat iv e r esp onse. Posit iv e r espon ses t o comm an d r equest s u su ally cont ain a 1- t o 3- by t e r espon se unit t hat ident ifies t h e com m and r equest . Posit ive r esponses t o d at a r equest s

cont ain r espon se h ead er s b ut no r esponse un it . Negat iv e respon se u nit s ar e 4 t o 7 b yt es long an d alw ay s ar e r et u r ned w it h a n eg at ive response. A r eceiv ing NAU ret u rn s a n eg at ive r esponse t o t he r equest ing NAU un der one of t h ree condit ions: Sender v iolat es SNA pr ot ocol • •

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Receiv erI ndex does not un derst and t h e t r ansm ission

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Unusual con dit ion, such as a pat h failur e, occu r s

By Cisco Systems, Inc.

When a n eg at ive response is t r ansm it t ed, t h e fir st 4 by t es of a response u nit cont ain dat a t hat Cisco expPub lainlish s er: w hy t h ePress r eq uest is un accept able. Th e r eceiv ing NAU sen ds u p t o 3 addit ion al by t es t hat Pub e: Sep tem ber 2 003 . ident if yDat t he r eject ed 1r1,equest I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Path Information Unit Format The p at h infor m at ion unit ( PI U) is an SNA m essage u nit f or med by p at h con t r ol elem ent s b y add in g a t r ansm ission header t o a BI U. Figur e 39 - 7 illust r at es t he PI U f or mat . •

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•

I ndex

Figu r e 3 9 -7 . Th e Pa t h I nf or m a t ion Un it ( PI U) Req ue st s an d Respon se s Each Con si st of Thr e e Fie lds

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

PIU Cov Fields erag e of cut t ing

edge t echn ologies lik e opt ical n et wor k ing and st or age

Aut h ored by Cisco Sy st ems, w or idet he leader in net or king or tillust he I nr at t ered n et The f ollow in g f ield descript ion s sum m ldw arize cont ent of wt he PI U, f as in. Figur e 39 - 7. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables w or kin g phe r ofessionals t oes unm derst and unit an ds im por. ar er net wcont ork ing Tranet nsm ission ad er — Rout essage t hrplem oughent thecont netem w ork Thyisint header ains t echnologies. Mast er tion he tf er con cep tSNA s, t echn ologies, d kdevices used ission in t oday ' s netfw orkat ing r out ing inf or mat ormt rs,adit ional subar ea netan w or in g. Tr ansm header orm s indu starrye. dif Lear n how t o incor por at e at intident er netificat w or kin echn inht ocont a LAN/ ir D onm ent . t o ferent iat ed by t he f orm iong (tFI D) tolog y pe.ies Pat r ol uWAN ses t henv e FI t y pes Com plet h anew an d SNA u pdatnodes. ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, r outeewditat am ong and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin p rof r egar dless of in ex PI pert Thr eeg FI D essionals, t y pes ar e im plem ent ed Us:ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e - ot FI ocols, D0 is used t o rvout datolv a bed et .ween adjacent bar ea nodinf esorfor on- SNA d ev ices.on har dw ar e, pr and ser icese inv Fu ndam ent al tsu ech nology matn ion is pr ov ided FIeD of 0 gint enegr er ally ender ed obsolet e by t he ing FI Ddet 4 bit set descr t o indicat er aquest dev ice a b r oad r ang al syisstrem s and serv ices, in clud ailed ipt ione s,w het rev hiew ions is an or rneh onev ice. t o en su re con ceptSNA comp enSNA sion dand r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy FI D1 r out eicdat a ur b et esen whvir enonm on eent ors bot h hich of t h e syst em s, pr-ovid in gisaused m or et or ealist pict e ween of t headjacent real- w or su ld bar n et ea w ornod k ing in w nod es do sup por ex id plicit andf orv iropt t u al out e syst p rotem ocols. pr of essionals oper at e.n ot Tools andt gu elines imrizing per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient o r out e dat a b et ween a subar ea b ound ary node an d an ad jacent decisions for- FI t hD2 eir is netused w orkts. per ipher al nod e, or bet w een adj acen t t y pe 2 . 1 n odes. I n general, t he t r ansm ission header is used t o r out e d at a b et w een adjacent su bar ea nod es w hen bot h t he su bar ea nodes sup por t ex plicit and v irt u al r out e p rot ocols. Re que st h ea de r— I d en t ifies t he t yp e of dat a in t h e associat ed r equ est unit s. This h ead er

pr ov ides infor m at ion about t he for m at of t h e dat a and specif ies p rot ocols f or t he session . On ly NAUs u se r equ est header infor m at ion. Re que st u nit — Cont ains eit h er en d- user dat a or SNA com m ands. End- u ser d at a is sent in dat a r eq uest un it s. SNA comm an ds ar e sen t in comm an d r equest u nit s t h at cont r ol t he net w or k and cont ain infor m at ion ex chan ged b et w een end u ser s. Re sponse he ad er — I d en t ifies t he t yp e of dat a associat ed w it h a r esp onse un it . The of Content s r eq uest Table / response in dicat or bit dist in guishes a response h ead er f r om a r equ est header. A • I ndex r eceivin g NAU ind icat es w h et h er t he r esp onse being r et u rn ed t o t he r equ est send er is I nt e rn posit et w oriv k ing Te negat chnologie H a ndbook Editbion e or iv es by set t ing, Four t h ethRTI it in t he r esp onse header . •

By Cisco Systems, Inc.

Re sponse uni t — Cont ains infor m at ion about t he r equ est in dicat ing eit h er a posit iv e or a negat iv e r esp onse. Posit iv e r espon ses t o comm an d r equest s u su ally cont ain a 1- t o 3- by t e Pub lish er: Cisco Press r espon se unit t hat ident ifies t h e com m and r equest . Posit ive r esponses t o d at a r equest s Pub Dat e: Sep tem ber 1 1, 2 003 cont ain r espon se h ead er s b ut no r esponse un it . I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 se u nit s ar e 4 t o 7 b yt es long an d alw ay s ar e r et u r ned w it h a n eg at ive response. Negat iv e respon A r eceiv ing NAU ret u rn s a n eg at ive r esponse t o t he r equest ing NAU un der one of t h ree condit ions: The sender v iolat es SNA pr ot ocol, a r eceiv er does not und er st and t h e t r ansmission, or an un usual cond it ion, such as a p at h failur e, occu rs.

When a n eg ive ion response isest t r ansm it t ed, h eone fir stnet 4 by t esing of ar efresponse u nitides contcover ain dat t hat The u pdat edatedit of t he b - selling all-tinw ork erence p rov agea of exp lain s w hy t h e r eq uest is un accept able. Th e r eceiv ing NAU sen ds u p t o 3 addit ion al by t es t hat essent ial an d cu t t ing- edg e t ech nologies. ident if y t he r eject ed r equest . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary I BM's SNA w as one of t he f ir st n et wor k ing pr ot ocols. Alt houg h it is now con sider ed a leg acy net w or kin g p rot ocol, it is st ill w id ely d ep loyed. SNA w as designed arou nd t he h ost - t o- t erm inal com mu nicat ion m odel t hat I BM' s m ainf ram es use. •

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•I BM ex pand ed I ndex t h e SNA pr ot ocol t o supp ort peer- t o- peer net w ork ing . This ex pansion was deem ed IAdv nt e rn et w or Peer k ing Te chnologie s Hw a ndbook th Edit ion Adv anced Prog ram - t o- Prog ram Com m unicat ion anced - t oPeer Net or k in g, Four ( APPN) and (ByAPPC) . Cisco Systems, Inc. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What did I BM cr eat e t o accom mod at e peer - based net w or k in g?

2:

I ndex ar e t he t yp es of phy sical ent it ies t h at I BM SNA supp ort s? What

• •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : What By Cisco Systems, Inc.ar e 4:

t he t hr ee t yp es of net w ork ad dr essable u nit s in SNA?

What is t h e fun ct ion of an LU?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

What is t h e fun ct ion of a PU?

I SBN: 1- 58 705 -1 19 -2 Pages: 28 6 : 11What

is t h e fun ct ion of a CP?

7:

Under APPN, w h at ar e t he w ell- defin ed nod e t y pes?

8:

What ar e t he four basic ser v ice cat egor ies for APPN?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of w hat helps n et wor k d ev ices locat e serv ice pr ov id er s? essent ial9 :an dI ncuAPPN, t t ing- edg e tser echvice nologies. 1 0 : For w hat is t he n et w or k t op ology dat ab ase used ? Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • ht t p: / / w w w . net w ork ing. ibm . com / app/ aiw conf / cp ic. ht m •

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•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 40. DECnet Obj e ct i ve s • •

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Descr ibe t he dev elop ment hist or y of t he D ECn et pr ot ocol, used p r im ar ily in D ig it al I ndex Eq uipm ent Cor por at ion m inicom put er s.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Descr Systems, ibe t he Inc.ar chit ect u re

of DECn et net w or ks.

Discuss t he ad dr essing m et h ods of DECnet .

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

Descr ibe im plem en t at ion and access m et h ods of DECnet . I SBN: 1- 58 705 -1 19 -2

Descr Pages: ibe 11 28ad dit ional pr ot ocols im plem en t ed in DECnet n et wor k s, including p rot ocols used in t he upp er lay ers of t he OSI ref er ence m odel.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction DECnet is a gr oup of dat a com mu nicat ions pr odu ct s, in clu ding a p r ot ocol su it e, developed and supp ort ed by Digit al Equipm ent Cor por at ion ( Digit al) . Th e fir st v er sion of DECn et , r eleased in 19 75, allow ed t w o dir ect ly at t ach ed PD P- 11 m in icom pu t er s t o com mu nicat e. I n r ecent y ear s, •Digit al has includ Table ed of Content s f or nonp r opr iet ar y pr ot ocols, bu t DECnet rem ains t h e m ost supp ort •im por t ant of IDigit ndex al's net w ork pr oduct off er ings. Th is chapt er p rov ides a su mm ar y of t he DECn et Ipr ntot e rn et w or k ing chnologie s Hw a ndbook th ect Editur ion ocol suit e, Te Dig it al' s net or k in g, Four archit es, and t he ov erall operat ion of DECnet t raf fic m anagem ent . Inc. By Cisco Systems, Figur e 40 - 1 illust r at es a D ECn et int er net w ork , w it h r out er s int ercon nect in g t w o LANs t h at Pub lish er: Cisco Press cont ain w ork st at ions an d VAXs. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 4 0 -1 . I n a DECne t - Base d I nt er n et w or k , Rout er s I nt er con n ect W or k st at ions a n d VAXs The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Sever al v er sions of DECnet hav e been r eleased. Th e fir st allow ed t w o dir ect ly at t ached Imn inicomp t ern et w or book , Four t h Ed it ion , is a com pr ehensive refer ence t hat ut kerinsgt oTech comnologies m unicatHand e. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er tex hepan t erded m s, tcon cep t s, t echn devices used tinfor t oday ' s ional net w ork ing Sub sequ en t r eleases he DECnet fun ctologies, ion alit y an bydad ding suppor addit indu ry ar . Lear n how t o incor por at e int er netrem w oraining kin g t echn ologible ies w initt h o at he LAN/ WAN env ent . pr oprstiet y and st andar d pr ot ocols, w hile com pat im m ediat elyirponm r eceding plet eThis w it hm new d utpdat edotchapt s on secur , st or opt ical net w or rCom elease. ean san t hat he pr ocols er are backw aritdy com p age, at ib le. Cur r en t ly, t wkoinvg,erscalabilit sions of y, and speed, h isw book is aDcom e an d IuVp-an t o-d dDatECn e r ef ence DECnet ar e tin ide u se: ECnplet et Phase eter / OSI . t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. DECnet Ph ase I V is t he m ost wid ely im plem en t ed v ersion of DECn et . How ev er, DECnet / OSI is Reader s wrecent ill obt ain a g reat er un der st an Iding LAN on and n et IwVorDkiging, ar t w icu lar ly t h e ect ur e t he most r elease. DECnet Phase V is of based t h WAN e Phase it al pNet ork Ar chit har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ( DNA) , and it supp or t s pr opr iet ary Digit al p rot ocols an d ot h er pr opr iet ary an d st an dar d ided on a r ang e of int al I sy s and ices, in clud det ailed descr Iipt s, vrev iew quest prbotr oad ocols. DECnet Phegr ase V st is em backw ar dserv comp at ible w iting h DECn et Phase I I ,ion t he ersion t hat ions tpr o eceded en su re itcon cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in gcalled a m orDeECn r ealist ic pict ur t he realor ld at n et w orwkiting en viret onm ent sI in w hich DECnet / OSI ( also et Phase V) eisofbackw ar d wcomp ible h DECn Phase V an d is pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease t he most recent v er sion of DECnet . This ver sion is based on t h e DECnet / OSI D NA. DECnet / OSI pr oduort ct siv it anset d imofprtov eff iciency, helpming t he eader e inprt elligent effher icient supp a ysub heeOSI pr ot ocols, ult ip le rpr opr ietmarake y Dmor ECnet ot ocols,, cost and -ot decisions for t h eir net w ork s. pr opr iet ar y and st andar d pr ot ocols.

DECnet Phase IV Digital Network Architecture The Digit al Net w ork Archit ect ur e ( DNA) is a com pr eh en siv e lay er ed n et wor k ar chit ect ur e t hat supp ort s a lar ge set of p rop riet ar y and st and ard pr ot ocols. The Ph ase I V DNA is sim ilar t o t h e ar ch it ect u re out lined b y t he OSI r ef erence m odel. As w it h t he OSI r ef erence m odel, t h e Phase I V •DNA ut ilizes a Table of ed Content layer ap prs oach, w her eb y specif ic layer f unct ions p r ovide ser vices t o p r ot ocol •lay er s abov e I it ndex and depend on pr ot ocol lay er s b elow it . Un lik e t h e OSI m odel, how ev er , t h e IPhase nt e rn etI w ing Te s H aof ndbook th Edit ion e 40 - 2 illust r at es how t he eight layer s of t h e VorDkNA is chnologie com pr ised eigh ,t Four lay ers. Figur Phase V D NA r elat By CiscoI Systems, Inc. e t o t h e OSI r efer en ce m od el. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Figu r e 4 0 -2 . Ph ase I V Con si st s of Eigh t La ye r s Tha t M ap t o t he O SI I SBN: 1- 58 705 -1 19 -2 La ye r s Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The f ollow in g sect ion d et ails t h e fu nct ionalit y and r ole of each of t hese lay er s an d ident if ies t he similar it ies b et ween t he Ph ase I V DNA ar chit ect ur e and t he OSI r ef erence m odel.

Phase IV DNA Layers The D ECn et Phase I V D NA defin es an eight - lay er m odel, as illust r at ed in Figur e 40 - 2. Th e user lay er r epr esent s t he User - Net w ork I n t erf ace, sup por t ing user ser v ices an d p rog ram s w it h a com mu nicat in g com pon en t . The user lay er cor respond s r ough ly t o t h e OSI ap plicat ion lay er . Th e net w or k m anagem ent lay er r ep resen t s t h e user int erf ace t o n et w or k - m anagem en t in for m at ion. This lay er int er act s wit h all t h e low er lay er s of t he D NA and cor respond s r ough ly wit h t h e OSI •app licat ion layer Table. of Content The net wsork ap plicat ion lay er pr ovid es v ar ious n et w or k ap plicat ion s, su ch as •r em ot e file access I ndex and v irt u al t er min al access. This lay er cor r espon ds r oug hly t o t he OSI Ipr ntesent e rn et wat orion k ingan Tedchnologie H a ndbook , Four th Edit ion ap plicatsion lay er s. By Cisco Systems, Inc.

The session cont r ol lay er man ages logical link conn ect ions b et ween en d n odes and corr espond s r ough ly t o t h e OSI session layer . The en d com m unicat ions lay er hand les f low cont r ol, Pub lish er: Cisco Press seg m en t at ion, an d r eassem bly fu nct ions an d cor r espon ds r oug hly t o t he OSI t ran spor t lay er . Th e e: Sep tem ber 1 1, 2 003 r outPub ingDat lay er perf or ms rou t ing and ot her f unct ions, an d cor r espon ds r oug hly t o t he OSI net w ork I SBN: 1- 58 -2 lay er . Th e dat a 705 lin-1 k 19 layer m anag es phy sical n et wor k chan nels and corr espond s t o t h e OSI d at a Pages: 11e 28ph ysical layer m anag es har dw ar e int erf aces and det er m ines t h e elect rical an d link lay er . Th m ech anical fu nct ions of t he phy sical media; t his lay er cor r esp onds t o t he OSI ph ysical lay er .

Phase IV DECnet Addressing

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. DECnet ad dr esses ar e not associat ed w it h t he phy sical n et wor k s t o w hich t h e nodes ar e connect ed. I nst ead, D ECn et locat es h ost s using area/ n ode add ress pair s. An area' s v alu e r anges fr om Con 1 t o cise 63 , ov inclusiv ise,olog a node ad dr tess bewor b etk w een an d 1 023 er v iewe.s Lik of ew t echn ies essen ial tcan o n et ing pr 1ofession als ,atinclusive. all lev els, f rom Ther efnov or e, each ar ea can h ave 1 023 n odes, and appr ox imat ely 65 , 000 nod es can be addr essed ice t o ex pert . in a DECnet net w ork . Ar eas can span m any rou t er s, and a sin gle cable can su ppor t man y ar eas. Ther efNew or e, chapt if a nod has sever netew of or kimint ertfaces, it uses e arEAP ea/ node addr ess for each er seinclude covalerag por ant t opics liket he VoIsam P and int er face. Figur e 40 - 3 illust r at es a sam ple DECnet net w ork wit h sever al add ressable ent it ies. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

Figu r e 4 0 -3 . D ECn et Loca t e s Host s Usin g Ar ea / Node Addr e ss Pa ir s

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DECnet h ost s do not use m anuf act u r er - assig ned Med ia Access Con t rol ( MAC) - lay er add resses. I nst ead, n et w or k level ad dr esses are em bedd ed in t he MAC- lay er ad dr ess accor ding t o an

algor it hm t hat mu lt ip lies t h e ar ea num b er by 10 24 and add s t he n ode nu m ber t o t he pr odu ct . The r esult ing 16 - bit d ecim al add ress is conv er t ed t o a hex adecim al n um ber and is app en ded t o t he addr ess AA00. 04 00 in b yt e- sw apped or der, w it h t he least - sign if icant b yt e fir st . For exam ple, DECnet ad dr ess 1 2. 75 becom es 1 236 3 ( base 10) , w hich equ als 304 B ( base 1 6) . Af t er t his b yt esw apped addr ess is append ed t o t he st an dar d D ECn et MAC addr ess pr efix , t he ad dr ess is AA00 .0 400 .4 B30. •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DECnet/OSI Digital Network Architecture The D ECn et / OSI ( DECnet Ph ase V) DNA is v er y similar t o t he archit ect ur e out lin ed by t he OSI r ef erence m odel. DECnet Phase V u t ilizes a lay er ed app roach t hat achieves a high degr ee of flex ibilit y in t er m s of suppor t for upp er - lay er p r ot ocol su it es. As t he f ollow ing sect ion discusses, •DECnet OSI act Table of Content ually allowss for t h e supp ort of m ult iple p rot ocol suit es. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

DECnet/OSI DNA Implementations By Cisco Systems, Inc.

lish er: ThePub D ECn etCisco / OSIPress DNA defines a lay er ed m odel t h at im plement s t hr ee pr ot ocol suit es: OSI , Pub Dat e: Sep ber 1ission 1, 2 003 Cont rol Prot ocol/ I nt er net Pr ot ocol ( TCP/ I P) . The OSI imp lem ent at ion DECnet , an d Trtem ansm I SBN: 158 705 -1 19 of DECnet / OSI conf or -2 m s t o t h e sev en- lay er OSI r ef erence m odel an d sup por t s m any of t he st andar d OSI p r ot ocols. Th e Digit al im plem en t at ion of DECn et / OSI pr ov ides back war d Pages: 11 28 com pat ibilit y w it h DECn et Phase I V an d su ppor t s m ult ip le pr opr iet ar y Dig it al pr ot ocols. The TCP/ I P im p lem ent at ion of DECnet / OSI sup por t s t he low er - layer TCP/ I P pr ot ocols and enables t he t ran smission of DECnet t r affic over TCP t r anspor t p r ot ocols. Figur e 40 - 4 illust r at es t he t hr ee DECnet / OSI im plem en t at ions.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r e 4 0 -4 . Th e OSI , DECne t , a nd TCP Ar e All Su ppor t ed by Con cise ov er v iew s of t echn olog ies DECne essen ttial / Ot oSIn etDNA wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DECnet Media Access DECnet Ph ase I V and DECnet / OSI sup por t a v ariet y of m edia- access im plem ent at ion s at t he ph ysical and dat a link lay er s. This h as cont r ibut ed t o t he r elat iv ely w id e accept ance of DECnet in t he com pu t er net w or king ind ust r y. As ex plained in t he f ollow ing sect ion s, bot h DECnet Ph ase I V •and Phase V Table of Content can sup por t ms any of t he com mon p hy sical an d d at a- link t echnologies in use t oday . •

I ndex

IAt nt et rn w or k ing Te chnologie s H a ndbook , Four th Edit heetph ysical lay er , D ECnet Phase I V and Dion ECnet / OSI su ppor t m ost of t he p opular phy sical im plem ent at ion s, inclu ding Et h er n et / I EEE 802 .3 , Tok en Rin g/ I EEE 80 2. 5, and Fiber D ist r ibu t ed By Cisco Systems, Inc. Dat a I nt erf ace ( FDDI ) . I n addit ion , DECnet / OSI sup por t s Fram e Relay an d X. 2 1bis.

At tPub he lish dater:a Cisco link Press lay er , D ECn et Phase I V an d D ECn et / OSI supp ort I EEE 80 2. 2 Logical Lin k Con t rol Pub Dat e: Sep tem berPr1oced 1, 2 003 ( LLC) , Link Access ur e, Balan ced ( LAPB) , Fr am e Relay , and High- Lev el Dat a Lin k Cont r ol I SBN: 158 705 -1 19 ( HDLC) . Bot h DECnet -2Phase I V and DECnet / OSI also su ppor t t he p rop riet ar y Digit al dat a- link pr ot ocol, Pages: Digit 11 28 al Dat a Com mu nicat ions Messag e Pr ot ocol ( DDCMP) , w hich pr ov id es point - t opoint and m ult ipoin t conn ect ions; full- du plex or half - dup lex com m unicat ion over sy nchr onous and asy nchr onous ch annels; and er ror cor r ect ion, sequ en cin g, an d m anag em ent .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DECnet Routing DECnet r ou t in g occur s at t he rou t ing layer of t h e DNA in DECnet Ph ase I V and at t he net w or k lay er of t he OSI m od el in DECnet / OSI . Th e r out ing im plement at ion s in bot h DECnet Ph ase I V and DECnet / OSI , h ow ev er, are sim ilar. •

Table of Content s

•DECnet Ph ase I ndex I V r out ing is im plement ed by t he DECnet Rout ing Pr ot ocol ( DRP) , w hich is a Ir nt e rnivetely w orsim k ingple Te chnologie s H a ndbook , Fourw thhose Edit ion elat an d ef ficient pr ot ocol p rim ar y fu nct ion is t o p rov ide op t imal pat h det er min at ion t h rou gh a D ECn et Phase I V n et w or k . Figur e 40 - 5 p r ovides a sam p le DECn et By Cisco Systems, Inc. net w or k t o illust r at e h ow t he rou t ing fun ct ion is p er f orm ed in a DECnet Phase I V net w ork . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 19 e -2 DRP De t e r m in es t he O pt i m al Rout e Th r ough a D ECn et Figu rI SBN: e 4 10 58 -5705 . -1 Th Pages: 11 28 Pha se I V Ne t w or k

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s,r ou pr tovid g a m or earreealist ic pict ur e of t he n et weorassigned k ing en vir DECnet in g in decisions based on cost , an ar realbit r arwyormldeasur byonm netent w orskin w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill ease adm inist r at or s t o b e used in com par in g var ious p at hs t h r ough an int er net w ork env irincr onm ent . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient Cost s t y pically ar e based on hop coun t or m edia bandw id t h, am ong ot h er measur es. Th e low er decisions h eir t he cost , tfor he tbet t ernet t hw e ork pats. h . When net w or k fault s occur , t he DRP uses cost v alues t o r ecalculat e t he best pat h s t o each dest in at ion. DECnet / OSI r ou t ing is imp lem ent ed by t he st an dar d OSI r out ing p rot ocols ( I SO 847 3, I SO 954 2, and I SO 105 89) and by D RP. Det ailed inf or m at ion on t h e OSI r out ing p rot ocols can be f ound in Ch apt er 48 , " Open Sy st em I nt ercon nect ion Rou t ing Prot ocol. "

•

Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DECnet End Communications Layer DECnet Ph ase I V supp ort s a single t r ansp ort pr ot ocol at t he D NA end com m un icat ion s layer : t h e Net w ork - Ser vices Prot ocol ( NSP) . •

Table of Content s

•

I ndex

Network-Services Protocol I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

The Net w ork - Ser vices Pr ot ocol ( NSP) is a pr opr iet ar y, con nect ion - orient ed, en d com m unicat ions pr ot ocol d ev elop ed b y Digit al t hat is r esponsible f or creat ing and t er m in at ing connect ions Pub lish er: Cisco bet w een nod es, Press p er f orm ing m essage fr agm ent at ion and r eassemb ly, an d man aging err or Pub Dat e: Sep tem ber 1 1, 2 003 cont r ol. I SBN: 1- 58 705 -1 19 -2

NSP also m an ages t w o t y pes of f low cont r ol: a sim ple st ar t / st op m echan ism in w hich t he Pages: 11 28 r eceiver t ells t he send er wh en t o t erm inat e and resum e dat a t r ansm ission, and a m or e comp lex sch em e in w hich t he r eceiv er t ells t h e send er how m an y messages it can accept .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DECnet/OSI Transport Layer DECnet / OSI su ppor t s NSP, t hr ee st an dar d OSI t r anspor t pr ot ocols, an d t he Tr ansm ission Cont r ol Pr ot ocol ( TCP) . •DECnet / OSI Table of tContent s su ppor s Tr anspor t Prot ocol classes ( TP) 0, TP2, an d TP4 . TP0 is t he sim plest OSI •connect ion- orI ndex ien t ed t r an sp ort pr ot ocol. Of t h e classic t r anspor t lay er fu nct ions, it p er f orm s on ly Iseg nt e m rn et ing an Te chnologie s Hbly a ndbook th Edit enwt or atkion d reassem . This, Four m eans t hion at TP0 w ill not e t he sm allest m ax im um - size pr ot ocol d at a un it ( PD U) su ppor t ed by t h e und er ly ing su bnet w or k s and w ill br eak t he t r anspor t By Cisco Systems, Inc. pack et int o sm aller pieces t h at ar e n ot t oo big for n et wor k t ran sm ission . TP2 can m ult iplex and dem ult iplex dat a st ream s ov er a single v ir t ual cir cu it . This capab ilit y mak es TP2 par t icu larly Pub lish er: Cisco Press usefu l ov er p ublic d at a n et w or k s ( PDNs) , in w hich each vir t ual cir cuit in cu rs a sep ar at e char ge. e: Sep tem ber 1 1, 2 003 As wPub it hDat TP0 and TP1, TP2 also segm en t s and r eassemb les PDUs, w h ile TP3 com bines t h e feat ur es I SBN: 1- 58 705 -1 19 of TP1 and TP2. TP4 , t-2h e most popu lar OSI t r ansp ort pr ot ocol, is similar t o t he I n t er net pr ot ocol 11 28 , in fact , w as b ased on t hat m odel. I n ad dit ion t o per for m ing TP3' s feat ur es, TP4 suit e'sPages: TCP and pr ov ides r eliable t r anspor t ser v ice an d assum es a n et wor k in w hich pr oblem s ar e n ot d et ect ed.

Requ est For Com ment s ( RFC) 100 6 an d RFC 1 006 Ex t ensions def in e an imp lem ent at ion of OSI t r anspor t lay er pr ot ocols at op t he TCP. RFC 100 6 defines t h e imp lem ent at ion of OSI Tr anspor t Pr ot ocol class 0 ( ion TP0 of ) on of - TCP. RFC extnet ensions d efrine t h e imp lemides ent at ion of The u pdat ed edit t het op b est selling all-10 in-06 one w ork ing ef erence p rov cover age of Tr anspor t Pr ot ocol class 2 ( TP2) on t op of TCP. essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

DECnet Phase IV Upper Layers The D ECn et Phase I V D NA specif ies f our u pper lay ers t o pr ov ide user int er act ion serv ices, net w or k- man agement capabilit ies, file t r ansfer , and session man agem en t . Specif ically , t h ese ar e r ef err ed t o as t he user layer , n et w or k m anag em ent lay er , net w or k applicat ion lay er , and session •cont r ol lay er .Table s Th e ofupContent per layer s of t he DECn et Phase I V ar chit ect ur e ar e discu ssed in m or e det ail •in t he f ollow ing I ndex sect ion s. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

User Layer Pub lish er: Cisco Press Dat user e: Sep tem 1 1,ppor 2 003t s u ser serv ices an d pr ogr am s t hat int er act w it h u ser ap plicat ion s. ThePub D NA lay ber er su I SBN: 158 705 -1 19 -2 The end u ser int er act s dir ect ly w it h t h ese app licat ions, an d t he app licat ions use t he ser vices and pr ogr am s pr11ov Pages: 28ided by t he user lay er .

Network Management Layer The ion of tent he bprest - selling oneinnet w ork efor erence rovp ides cover The u n pdat et wored k - edit m anagem ot ocol w id allely inu sed DECn eting netrw k s is tphe rop r iet ar y age Digitofal essent ial an d cu t t ingedg e t ech nologies. Net w ork I n for m at ion an d Cont r ol Exchan ge ( NI CE) pr ot ocol. NI CE is a com m and- r esponse pr ot ocol. Com m and s, wh ich r equest an act ion, ar e issu ed t o a m anag ed n ode or p rocess; r espon ses, in t he f or m of act ions, ar e r et u rn ed b y t hose nod es or pr ocesses. NI CE p er for m s a Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom v ariet y of n et w or k m anag em ent - r elat ed f unct ions an d can be used t o t r ansfer an oper at ing nov ice t o ex pert . syst em f rom a local syst em int o a rem ot e syst em , as w ell as enable an u nat t ended r em ot e syst em t o chapt dum peritss include m emor ycov t oerag t he elocal sypor st em . Prt opics ot ocols using CE EAP can ex am in e or chang e New of im t ant like VoI PNIand cer t ain char act er ist ics of t he net w or k. NI CE su ppor t s an event logger t hat au t om at ically t r acks im porCov t anterag netew or evtent sucht echn as an adj acency chang or wor a cir cuitand - st atst e or chan of kcut ing s,edge ologies lik e opt ical en et k ing agege. NI CE su ppor t s fu nct ions t h at accom mod at e har dw ar e an d n ode- t o- nod e loop t est s. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Cer t ain n et wor k m an agement fu nct ions can use t he Maint enance Operat ions Prot ocol ( MOP) , a collect ion ofkfun ion snologies t hat canHand op erbook at e w, itFour h outt ht he esen t he DNA lay errefer s betence w eent hat t he I n t ern et w or in gctTech Ed itprion , iscea of com pr ehensive net w or k m anagem ent an d dat a link lay er s. This allow s access t o n odes t hat exist in a st at e ing in enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork w hich only dat a lin k layer ser vices are available or operat ion al. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, tApplication h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Network Layer net w or kin g p rof essionals, r egar dless of ex pert ise. Dat a- Access ocola (gDAP) , aun prder oprstiet D igit al pr and ot ocol, is un sed byk ing, DECnet Reader s w ill Pr obtotain reat er anary ding of LAN WAN et w or p ar tPhase icu lar lyI Vt hate t he net w or k app licat ion layer . DAP su ppor t s r em ot e file access an d r em ot e file t r ansf ser hat har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion er is, pr ovvices ided ton ar e used b y app licat ions at t he net w ork man agement lay er and t he u ser lay er . Ot her pr opr iet ar a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ionsy Digit ocols g at t h e net applicat ion ad laydit erional include MAI L, w hich s udy the . t o enal su pr re ot con ceptoperat compin r eh en sion andw ork r et en t ion, and r esou r ces f or fu rtallow her st exchan ge of m ail m essages, and CTERM, wh ich allow s r em ot e in t er act ive t er m inal access. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it yControl an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Session Layer decisions for t h eir net w ork s. The Session Cont r ol Pr ot ocol ( SCP) is t he DECnet Phase I V session cont rol- lay er pr ot ocol t hat per for m s a n um ber of f unct ions. I n par t icular, SCP r equ est s a logical lin k fr om an end dev ice, r eceives logical- link r eq uest s fr om end dev ices, accep t s or r eject s logical- link requ est s, t r anslat es nam es t o ad dr esses, and t er m inat es logical link s.

DECnet/OSI Upper Layers The D ECn et / OSI DNA is based on t he OSI r ef erence m odel. DECnet / OSI su ppor t s t w o pr ot ocol suit es at each of t he u pper lay er s: t h e OSI p rot ocols an d t he DECnet Phase I V pr ot ocols ( for back w ard com pat ibilit y ) . DECnet / OSI sup por t s f unct ionalit y in t he applicat ion, pr esen t at ion, an d •session lay ers. Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Application Layer By Cisco Systems, Inc.

Pub lish er: Cisco Press en t s t h e st andar d OSI app licat ion layer im plem en t at ions, as w ell as DECnet / OSI im plem Pub Dat e: Sep tem 1, 2 003p rocesses such as Com m on Managem ent - I nf orm at ion Pr ot ocol ( CMI P) st andar d app licat ber ion1 layer I SBN: 158 705 -1 19 -2 and File Tran sf er, Access, an d Managem ent ( FTAM) , am ong ot her s. DECn et / OSI also supp or t s all t he pr Pages: ot ocols im p lem ent ed b y DECnet Ph ase I V at t h e user and net w or k- man agement lay er s of 11 28 t he DNA, such as t he Net w or k I nfor m at ion and Cont rol Ex ch ange ( NI CE) p r ot ocol.

The OSI app licat ion layer includ es act u al app licat ions, as w ell as ap plicat ion serv ice elem en t s ( ASEs) . ASEs allow easy com m unicat ion fr om ap plicat ion s t o low er lay er s. The t hr ee m ost im por t ant ASEs ar e Associat ion Cont rol Ser v ice Elem ent ( ACSE) , Remot e Oper at ions Ser vice The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Elem en t ( ROSE) , an d Reliab le Tran sf er Ser v ice Elem ent ( RTSE) . ACSE associat es applicat ion essent ial an d cu t t ing- edg e t ech nologies. nam es w it h one anot her in p r ep arat ion f or applicat ion- t o- ap plicat ion com mu nicat ions. ROSE im plem ent s a gener ic r eq uest - reply m echanism t hat per m it s r em ot e op er at ions in a man ner similar t ocise t hatov oferrvem re calls ( RPCs) eliab deliv ery in gels, session Con iewotseofp rocedu t echn olog ies essen t ial. RTSE t o n et aids wor kring prle ofession alsby at m allaklev f rom lay er nov const r uct s easy t o use. ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Presentation Layer

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

DECnet / OSI im by plem en t sSy allsttems, h e st andar d ide OSIleader p resenint at ionw or layer plement Aut h ored Cisco w or ldw net kingim f or t he I n at t erion n ets.. DECnet / OSI also supp ort s all t he pr ot ocols im plem en t ed b y DECnet Ph ase I V at t h e net w or k applicat ion lay er of he et DNA. ostnologies im p ort an t of tbook h ese, is t h et hDat Access ot ocol ( D AP) . refer ence t hat I n ttern w or kThe in g m Tech Hand Four Edait ion , is aPrcom pr ehensive enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing The OSI pr esent at ion y pically is jtust passt hr ougan h dp rot ocol for inf or at ion' sf rnet omwadj t echnologies. Mast er t lay he er t ertm s, con cep s, t a echn ologies, devices used in m t oday orkacent ing lay er s. Alt hou gh man y people b elieve t hat Ab st ract Syn t ax Not at ion 1 ( ASN. 1 ) is OSI ' s indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . pr esent laynew er pran otdocol, ASN.1 is uer sed for secur ex pr it essing a for mical at s net in aw m ind ep eny, dent Com pletat e ion w it h u pdat ed chapt s on y , st ordat age, opt orachinek in g, scalabilit for m at . Th is allow s com m un icat ion bet w een app licat ions on d iv er se com pu t er sy st ems ( ESs) a and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t oinall m anner t r an sp arent t o t he app licat ions. net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Session Layer a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . DECnet / OSI im plem en t s all t h e st andar d OSI session layer im plem en t at ions. DECnet / OSI also Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy supp ort s all t he pr ot ocols im plem en t ed b y DECnet Ph ase I V at t h e session cont rol lay er of t he syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich DNA. Th e pr im ary session cont r ol lay er pr ot ocol is t he Session Cont r ol Pr ot ocol ( SCP) . The OSI pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease session lay er pr ot ocol t u rn s t he d at a st r eams pr ovid ed by t he low er fou r layer s int o session s by pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient im plem ent in g v ar ious cont r ol m echanism s. These m echanism s include account in g, conv er sat ion decisions for t h eir net w ork s. cont r ol, and session- p aram et er negot iat ion. Session conv er sat ion cont r ol is im plem en t ed b y use of a t oken, t he possession of wh ich pr ov ides t he righ t t o com mu nicat e. The t ok en can be r eq uest ed , and ESs can be g r ant ed p r ior it ies t hat pr ov id e for unequ al t ok en u se. Figur e 40 - 6 illust r at es t he com plet e DECnet Phase I V and DECnet / OSI pr ot ocol suit es, in clu ding t he im p lem ent at ion of DECnet / OSI ov er TCP.

Figu r e 4 0 -6 . D ECn et Pha se I V an d D ECn et / OSI Su ppor t t h e Sa m e Da t a Li nk an d Ph ysica l La ye r Spe cif icat ions

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Table of Content s

•

I ndex

[ View full size im age]

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary The b en ef it s of t h e DECnet pr ot ocol ar e r ealized in sp ecific n et w or k s using Digit al eq uipm ent . Few net w ork s st ill u se D ECn et , but y ou m ay encoun t er t hem in som e legacy sy st em s. •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: • •

How d o DECnet host s use t h e man uf act u r er - assig ned Med ia Access Con t rol ( MAC) Table of Content s add ress? I ndex

I nt e rn et w Te chnologie s Hin a ndbook , Four Edit 2 :or k ing What pr ot ocol DECnet Ph th ase I Vionis

r espon sible f or r out in g?

By Cisco Systems, Inc.

3:

What f unct ions d oes Net w or k - Ser v ices Pr ot ocol ( NSP) pr ovid e?

Pub lish er: Cisco Press

4:

What f unct ions d oes t he Session Cont rol Prot ocol ( SCP) p r ovide?

Pub Dat e: Sep tem ber 1 1, 2 003 I5 SBN: 58 705 -1 19lay -2 er : 1The u ser

pr ov id es w hat t yp es of f un ct ion s in D ECn et ?

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Part VII: Routing Protocols Ch apt er 41 Bor d er Gat ew ay Prot ocol • •

Ch apt er 42 Enhan ced I GRP Table of Content s

Ch apt er 43 I BM Sy st em s Net w ork Archit ect ur e Rou t ing I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ch apt er 44 I n t er ior Gat ew ay Rout ing Pr ot ocol

By Cisco Systems, Inc.

Ch apt er 45 I n t er net Prot ocol Mult icast

Cher: aptCisco er 46 Net War e Pub lish Press

Lin k- Ser v ices Pr ot ocol

Pub Ch Datapt e: Sep 1 1, 2 003 er tem 47ber Open Sh or t est

Pat h Fir st

I SBN: 1- 58 705 -1 19 -2

Ch apt er 48 Open Sy st em I nt er con nect ion Rou t ing Pr ot ocols

Pages: 11 28

Ch apt er 49 Rout ing I nf orm at ion Pr ot ocol Ch apt er 50 Resour ce Reser v at ion Prot ocol Ch apt er 51 Sim ple Mult icast Rout in g Pr ot ocol The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 41. Border Gateway Protocol Obj e ct i ve s • •

Table of Content s

Under st and t he p ur pose of t he Bor der Gat ew ay Pr ot ocol. I ndex

I nt e rn Ex et wplain or k ingBGP Te chnologie H a ndbook Four th Edit at t rib utses and t h,eir u se in rion out e

select ion.

By Cisco Systems, Inc.

Ex am ine t h e BGP r out e select ion pr ocess. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction The Bor der Gat ew ay Pr ot ocol ( BGP) is an int er aut on om ous sy st em r out in g p r ot ocol. An aut on om ous syst em is a net w or k or gr oup of net w or k s und er a com mon ad min ist r at ion and w it h com mon r out ing p olicies. BGP is u sed t o ex ch ange rou t ing infor m at ion for t he I nt er net an d is t he •pr ot ocol u sedTable ofeen Content s net serv ice pr ovid er s ( I SP) . Cust om er net w ork s, such as univ ersit ies bet w I nt er •and cor por at Iions, ndex usually em ploy an I nt erior Gat eway Prot ocol ( I GP) such as RI P or OSPF for t he Iexchan nt e rn et w k ing Te chnologie a ndbook , Four Edit n ion georof r out in g inf orsmH at ion w it hin th t h eir et w or k s. Cust om ers con nect t o I SPs, an d I SPs u se BGP t o Systems, ex ch ange cu st om er and I SP r out es. Wh en BGP is used b et ween aut onom ous sy st ems By Cisco Inc. ( AS) , t h e pr ot ocol is r efer red t o as Ex t er n al BGP ( EBGP) . I f a ser v ice p rov ider is using BGP t o exchan ge r out es w it hin an AS, t h en t he pr ot ocol is r ef er r ed t o as I nt er ior BGP ( I BGP) . Figur e 41 Pub lish er: Cisco Press 1 illust r at es t his d ist in ct ion . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 4 1 -1 . Ex t e r na l a n d I nt er i or BGP

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har pr otr ob ocols, and ser v ices rinv Fuocol, ndamas entev alidenced t ech nology inf or mat ion BGP is pr is ovtided BGPdw isara e, v ery ust an d scalable outolv ingedpr. ot by t he f act t hat he on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions r out ing pr ot ocol em ploy ed on t he I n t er n et . At t h e t im e of t his w r it ing, t he I nt er net BGP r out ing tt o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ables nu m ber m ore t han 90, 0 00 rou t es. To achieve scalabilit y at t his lev el, BGP uses man y Cov e is also end edatnt rib ot ut only n etrwor k ingp olicies concep and t s, but also t oaold er , legacy r outerag e p aram et ers,ext called es, t too new d ef ine out ing m ain t ain st able r out ing syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in w hich env iron ment . pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr ct iv it yt oanBGP d imat prtov e teff help ing t he rain eader mor e in elligent cost -t eff I n odu addit ion r ibu es,iciency, classless int er dom r outm inake g ( CI DR) is tused b y, BGP o ricient ed uce t he decisions for t h eir net w ork s. size of t he I nt er net rou t ing t ables. For ex am ple, assu me t hat an I SP ow ns t he I P add ress block 19 5. 10. x . x fr om t h e t r adit ional Class C ad dr ess space. This b lock con sist s of 25 6 Class C ad dr ess block s, 195 .1 0. 0. x t hr ou gh 195 .1 0. 25 5. x. Assum e t h at t h e I SP assig ns a Class C block t o each of it s cust om ers. Wit h out CI DR, t he I SP w ould adv er t ise 2 56 Class C addr ess block s t o it s BGP peers. W it h CI D R, BGP can sup er net t he ad dr ess space an d ad ver t ise one block , 19 5. 10. x . x. This block is t h e sam e size as a t r adit ional Class B add ress block. The class dist inct ions ar e r en der ed

obsolet e by CI D R, allow ing a signif ican t r educt ion in t h e BGP rou t ing t ables. BGP neighbor s ex change full rou t ing infor m at ion w hen t he TCP con nect ion b et w een n eig hbor s is fir st est ablished. Wh en chan ges t o t h e r out ing t ab le are d et ect ed, t h e BGP rou t ers send t o t heir neighb or s only t h ose r out es t hat hav e ch anged. BGP r out er s do not sen d p er iodic r out in g up dat es, and BGP rou t ing upd at es adv er t ise only t h e opt im al p at h t o a dest in at ion n et w or k . •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

BGP Attributes Rou t es lear ned via BGP h ave associat ed pr op er t ies t hat ar e used t o det erm ine t he best r ou t e t o a dest inat ion w hen m u lt ip le pat hs ex ist t o a p art icular d est inat ion . These pr oper t ies are r efer r ed t o as BGP at t r ibut es, and an un derst an ding of how BGP at t r ibu t es influ en ce r out e select ion is •r eq uir ed f or tTable of Content he d esign of rsobu st net w or ks. Th is sect ion descr ibes t he at t rib ut es t hat BGP uses in •t he rou t e select I ndex ion p rocess: I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Weight

PubLocal lish er: pCisco ref erPress ence Pub Dat e: Sep tem ber 1 1, 2 003

Mu lt i- ex it 705 d iscr im-2inat or I SBN: 1- 58 -1 19 Pages: 11 28

Or igin

AS_p at h Next hop The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of m un it yt t ing- edg e t ech nologies. essentCom ial an d cu Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing Weight Attribute nov ice t o ex pert .

pr ofession als at all lev els, f rom

WeighNew t is achapt Ciscot r ibut e et hat is por local to a rou t er . Th ew ht EAP at t r ib ut e is n ot ad ver t ised er sdefined includeatcov erag of im t ant t opics like VoI Peig and t o neig hbor ing r out er s. I f t he r out er learn s abou t m or e t han on e rou t e t o t he sam e dest inat ion, Cov ing edge echn lik ered. opt ical n et wor k ing t he rou t eerag w it he t of he cut h igt hest w eig tht w illologies be pr efer I n Figur e 41 - 2, and Routst erorAage is r eceiv ing an adv ert isem en t f or net w or k 172 . 16. 1. 0 fr om r ou t er s B and C. W hen Rout er A r eceiv es t he h ored Cisco ems, or ldw ide f or t heRou I n tt er adv ertAut isem en t fby rom RoutSy erstB, t he wassociat ed leader w eig htinisnet setwtor o king 50 . When er nAetr.eceives t h e adv ert isem en t f rom Rout er C, t he associat ed w eight is set t o 1 00. Bot h pat hs f or n et w or k I17 n t2. ern et1w.0 or w k in Tech , Four t hh Ed it ionrespect , is a com preight ehensive 16. illgbe in nologies t h e BGP rHand out inbook g t able, w it t heir iv e w s. Th erefer r outence e w itthhat t he enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing high est w eig ht w ill b e inst alled in t he I P r ou t in g t able. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a Figu com plet t o- d at e enceAt t ot trhe t op r ee 4an1d-2u p. BGP Wr ef eierght i bu t eics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

Local novPreference ice t o ex pert . Attribute

Newp refer chaptence er s include por t opics like VoI Pt he andlocal EAPau t onom ous sy st em The local at t rib utcov e iserag u sede of t o im p ref er t ant an ex it poin t f rom ( AS) . Unlik e t he w eight at t r ibu t e, t he local pr efer en ce at t r ib ut e is p r opagat ed t hr oug hout t he Cov erag e of cut ing t echn ologies lik et hopt icalt he n et local wor k ing st orat age local AS. I f t her e ar e tm ultedge iple exit point s fr om e AS, p refand er ence t r ibut e is used t o select t h e exit point for a specif ic rou t e. I n Figur e 41 - 3, AS 100 is r eceiv in g t wo adv ert isem en t s Aut h ored Cisco Syom st ems, w or. ldw ide Rout leader in r net w or king or ter het isement I n t er n etfor . net w ork for net w ork 172by .1 6. 1. 0 fr AS 200 When er A eceives t h e fadv 17 2. 16. 1 .0 , t he cor r espon ding local pr efer en ce is set t o 50 . Wh en Rou t er B r eceives t h e I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat adv ert isem en t f or net w or k 172 . 16. 1. 0, t he cor r espon ding local pr eference is set t o 10 0. Th ese enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing local pr efer en ce v alues w ill be ex chang ed bet w een r out er s A an d B. Becau se Rout er B h as a t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing high er local pr ef erence t h an Rout er A, Rout er B w ill b e used as t he exit point fr om AS 100 t o indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . r each net w or k 17 2. 16. 1. 0 in AS 20 0. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

r eer4un 1 -3 l Pr e f WAN er e nce r ibup ar t et icu lar ly t h e Reader s w ill obt ainFigu a g reat der.stBGP an dingLoca of LAN and n et wAt or kting, har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Multi-Exit Discriminator Attribute New chapt er s include cov erag e of im por t ant

t opics like VoI P and EAP

The m Cov ult i-erag ex it ediscr im inat ( M ED) or ologies m et ric at is nused ask ing a suand ggest ionage t o an ext er nal AS of cut t ingor edge t echn likter ibut opt e ical et wor st or r eg ar ding t he p ref er r ed r out e int o t he AS t hat is adv er t isin g t he m et r ic. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The t er m suggest ion is used because t he ex t ern al AS t hat is receiv ing t he MEDs m ay b e using Iot n her t ernBGP et w oratktin g Tech nologies Four Ed it iont h, eisr a com pr ehensive enceion t hat r ibu t es for r out e Hand selectbook ion . ,We w tillh cover ules regar d in g r ourefer t e select in t he enables g p reofessionals o un derst an d tim t cont em1.por eret net ork1ing nex t sectnet ionw. or I nkin Figur 41 - 4, Routter C is advand er t ising heplem r outen e 172 . 16. 0 warityh int am ricwof 0, twechnologies. er ert he t er m172 s, con devices in of t oday s net hile Rou t e D Mast is adv t ising . 16.cep 1. 0t s, w itt echn h a mologies, et ric of an 5 . dThe low erused v alue t he 'met r icw ork is ing indu st red, ry . Lear n how incor por at e int olog LAN/ ent . pr efer so AS 1 00 t o w ill select t he r ouert enet t owror oukin t erg Dt echn f or net w ies or k in 17t o2.a16. 1. 0WAN in ASenv 20ir0.onm MEDs Com pletert ew it h new an dout u pdat chapt ar e adv ised t hr ough t heed local AS.er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a der st an LAN andscr WAN k ing, t icutlar Figu r eg reat 4 1 er -4 un . BGP Mding ul t i of -Ex it Di im ninetawtoror At tprar i bu e ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Origin Attribute New chapt er s include

cov erag e of im por t ant t opics like VoI P and EAP

The orCov iginerag at t r ibu in tdicat es how BGP lear ned abou a par icu lar r out e. The or igin at t r ibu t e can e oft ecut ing edge t echn ologies lik e opt tical n ett wor k ing and st or age hav e one of t hr ee possib le values: Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . GP— out enologies is in t er ior t o tbook he or, igin v alue set w hen refer t he net w ork I n t ernI et w or kThe in g rTech Hand Fouratt ing h EdAS. it ionThis , is a com is pr ehensive ence t hatr ou t er conf ig ur at ion com m and is used t o inj ect t he r out e int o BGP. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing The r out teoisincor learpor nedatvia t he Ex twerorior der Gat ewies ayinPrt ootaocol ( EBGP) . indu stEGP— ry . Lear n how e int er net kinBor g t echn olog LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, I ncom ple t e — The or igin of t he r out e is unk now n or learn ed in some ot her w ay. An origin and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all of incom plet e occu rs w h en a rou t e is r ed ist r ibu t ed int o BGP. net w or kin g p rof essionals, r egar dless of ex pert ise. The or igin at t r ibu t e is used f or r out e select ion and w ill be cov er ed in t h e nex t sect ion . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con AS_path Attribute cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst emas,r out pr ovid in ger at isement m or e r ealist ic pict e ofan t heaut realw orous ld nsy etst wem or k,ing virnu onm ent sisinadded w hicht o When e adv passes t hr ur ough on om t h een AS m ber pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease an or dered list of AS nu m bers t hat t he r out e adv er t isem ent has t r av ersed. Figur e 41 - 5 sh ows t he pr ct iv it d ima pr ovtee eff ing t the r eader m akeous mor t elligent , cost - eff icient sitodu uat ion iny wan h ich r ou is iciency, passin g help t hr ough h ree au t onom syestin em s. decisions for t h eir net w ork s.

Figu r e 4 1 -5 . BGP AS-p at h At t r ibu t e

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut in h ored leader in net king I n dt erAS n et3, . w it h t he AS1 orig at es by t heCisco r out eSy t ost1ems, 72. 16w. or 1. 0ldw anide d adv er t ises t hisw ror out e t of or ASt he 2 an AS_p at h at t rib ut e equ al t o { 1} . AS 3 w ill adv er t ise back t o AS 1 w it h AS- pat h at t r ibut e { 3, 1} , I n t ern k inad g ver Tech nologies th h Edat it tion ehensive refer ence t hat and ASet 2w or w ill t ise b ack t oHand AS 1book w it h, Four AS- pat rib,utise a{ 2com , 1} pr . AS 1 w ill reject t hese r ou t es enables kinnu g mb p r ofessionals o un imtplem int er net wtork w hen it snet owwn or AS er is det ectted in derst t he rand out ean addver isem en entt .cont Th isem is por t hearmyechanism hating BGP t echnologies. t er mAS s, con cepAS t s, 3t echn ologies, an dr out devices usedotinh er t oday ork ing uses t o det ect Mast rou ter ingt he loops. 2 and p r opagat e t he e t o each wit h' st net h eirwAS indu ster rys. ad Lear n how incor por net w or kin g tt echn olog t o aalled LAN/inWAN ir onm nu mb ded t o t hteo AS_pat h at atet r int ibuer t e. These rou es w ill notiesbeininst t he env I P rou t ingent . e w it h AS new pdat ede chapt ergs aonr out secur , st or age, icalAS net1wworitkhinag,shscalabilit y, tCom ableplet b ecause 2 an andd u AS 3 ar lear nin e t it o y172 . 16. 1. 0 opt fr om or t er and speed, AS_p at h listt.h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Next-Hop Attribute har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o enEBGP The su re con nexcept t - hopcomp at t rib r eh uten e is sion t h eand I P add r et en r ess t ion, t h at and is ad u sed dit ional t o r each r esou t hreces advf or ertfu ising rt herr out st udy er . .For Cov EBGP erag peers, e is also t he nex ext end t - hop ed add n ot ress only ist ot hnew e I Pnadd et wor ress k ing of tconcep he contnect s, but ionalso bet wt oeen oldter h e, legacy peer s. For syst I BGP, emt s, h epr EBGP ovid in nex g at - m hop or eaddr r ealist essicispict carruried e ofintthe o t hreale local w orAS, ld n et aswillust or k ing r at en ed vir in onm Figur ent e s41in- 6. w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figu r e 4 1 -6 . BGP Ne xt -H op At t r i bu t e

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Rou t er C ad ver t ises n et wor k 1 72. 16 . 1. 0 w it h a next hop of 10 .1 .1 . 1. Wh en Rou t er A p rop agat es New erag e ofnim t antinft opics VoIp P andv ed. EAPI f Rout er B does not t his r ou t e chapt w it hineritss include ow n AS,cov t he EBGP expor t - hop or matlike ion is reser hav e r out in g inf or m at ion r egar ding t h e next hop , t he r ou t e w ill be d iscar ded. Ther efor e, it is of cut t echn ical neetnext wor-khop ing and st orinf age im porCov t anterag t o heave ant ing I GPedge r unn in g in ologies t h e AS lik t o epropt opagat rou t ing orm at ion. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

Community I n t ern et w or k in g Attribute Tech nologies Hand book , Four t h

Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. hee tperrov m ides s, cona cep t s,oft echn ologies, aninat d devices used com in t oday nettwoork The com m unitMast y at ter r ibtut way gr ouping d est ion s, called m unit' sies, w hing ich st rydecision . Lear n how t o incor por atan e int w or kin g and t echn ologries t o )acan LAN/ env .irRout onm e ent . rindu out ing s ( such as accept ce,erpnet refer ence, redist ibutinion beWAN ap plied Com it h new ant d edu nit chapt ont e. secur it y ,insted or age, optnit ical net ortkes in g, y, m apsplet ar ee uwsed t o set h eu pdat comm y ater t rsibu Predef com mu y at trw ibu arescalabilit list ed here: and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. no- ex por t — Do n ot ad ver t ise t his r out e t o EBGP peers. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e adprve i se — and Do nser ot vad verinv t iseolvt his outndam e t o any . nology inf or mat ion is pr ov ided on har dwnoar e, otrtocols, ices ed . r Fu ent alp eer t ech a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions in treercon ne tcept — Adv er t ise hission r outand e t or et t hen e It nt er net muional nit y ;r esou all r ou t er fsorin fut he netst w udy ork . t o en su comp r ehten ion, andcom ad dit r ces rt her belong t o it .ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Cov erag e is also syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Figur e 41 - 7 illust t he noexpgu ortidcomm nit yopt . AS 1 advsyst ert ises 16. .0 t o wAS 2 w it h t he pr of essionals operr at ates e. Tools and elines uf or im izing em 17 per2.for m1ance ill incr ease com mu nit y at t r ibu t e noex por t . AS 2 w ill pr op agat e t h e r out e t h rou ghou t AS 2 b ut w ill not pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icientsend t his r ou t e for t o AS 3 or ots. h er ex t er nal AS. decisions t h eir netany w ork

Figu r e 4 1 -7 . BGP no- ex por t Com m u ni t y At t r i but e

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise er v1iew of ttises echn1olog essen ial 2t ownitet ing pr ofession ate all els, rom I n Figur e 41 - 8,ovAS adsver 72. 1ies 6. 1. 0 t o tAS h wor t hekcom m un it y at tals r ibut n o-lev adv ertfise. nov ice t o ex pert . Rou t er B in AS 2 w ill not adv er t ise t his r ou t e t o an y ot her r out er . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Figu r e 4 1 -8 . BGP no- ad ve r t ise Com m u ni t y At t r i bu t e

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Figur e 41 - 9 d em on st r at es t h e int er net com mu nit y at t r ibu t e. Ther e are no lim it at ions t o t he scop e of t he r ou t e adv ert isement f rom AS 1.

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r e 4s 1 -9 . TableFigu of Content

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I ndex

BGP in t e r ne t Com m un it y At t r ibu t e

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

BGP Path Selection BGP cou ld p ossibly r eceiv e m ult iple adv ert isem en t s for t he sam e r out e f r om m ult iple sour ces. BGP select s only one p at h as t he b est pat h . When t he p at h is select ed, BGP p ut s t h e select ed pat h in t he I P rou t ing t able an d p r opagat es t h e pat h t o it s neighb ors. BGP uses t he follow in g •crit er ia, in t he Table of Content or der p resens t ed, t o select a p at h for a dest inat ion: •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

I f t he p at h sp ecifies a next hop t hat is inaccessible, dr op t he up dat e.

By Cisco Systems, Inc.

Pr ef er t he p at h w it h t h e lar gest w eig ht . Pub lish er: Cisco Press Pub I fDat t he e: w Sep eight tem ber s are 1 1, 2t003 he

sam e, pr ef er t he p at h w it h t h e lar gest local pr ef erence.

I SBN: 1- 58 705 -1 19 -2

IPages: f t he local p refer ences ar e t he sam e, p r ef er t he p at h t hat was orig in at ed b y BGP r u nning 11 28 on t his r out er . I f no rou t e w as or iginat ed, p r ef er t he r out e t hat has t h e sh or t est AS_pat h . I f all pat h s hav e t he sam e AS_ pat h len gt h, pr ef er t he p at h w it h t h e low est orig in t y pe The u(pdat w hered e Iedit GP ion is low of er t het han b estEGP, - selling andallEGP in- one is low net erwt ork haning incom r ef erence plet e) . p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. I f t he or igin codes ar e t he sam e, pr efer t he pat h w it h t he low est MED at t r ibut e. I f t he Con cise p atov hserhvave iew st he of tsam echne olog MED, iespressen efer t he ial tex o tnern et wor al pat k ing h ov prer ofession t he in als t er nat al all patlev h . els, f rom nov ice t o ex pert . I f t he p at hs ar e st ill t he sam e, pr efer t h e pat h t h rou gh t he closest I GP neigh bor . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Pr ef er t he p at h w it h t h e low est I P add ress, as specif ied by t he BGP rou t er I D. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: •

Can I BGP be used in place of an I GP ( RI P, I GRP, EI GRP, OSPF, or I SI S) ? Table of Content s

ndex AssuIm e t hat a BGP r out er is learn in g t he sam e r out e f rom t w o d if fer en t EBGP p eer s. I nt e rn et w The or k ing Te chnologie s H a ndbook Edit1ion AS_ pat h inf orm at ion fr, Four om th p eer is { 2345 , 86, 51 } , an d t he AS_p at h in for m at ion fr om peer 2 is { 234 6, 51} . What BGP at t r ib ut es could be ad just ed t o f or ce t he r out er By Cisco Systems, Inc. t o pr ef er t he r out e adv er t ised b y peer 1? •

2:

Pub lish er: Cisco Press

3:

Can BGP be u sed only by I n t er n et ser v ice p rov ider s?

Pub Dat e: Sep tem ber 1 1, 2 003

4:

I SBN: -2 nect ed I f a1-d58 ir 705 ect-1 ly19con Pages: 28 e at t r11 ibut

int er face is r edist ribu t ed in t o BGP, w hat v alue w ill t h e or igin hav e for t his r out e?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • RFC 1 771 , " BGP4 " •

Table of Content s

•• Halab i, Bassam I ndex . I n t ern et Rou t ing Ar ch it ect ur es. Cisco Pr ess: I ndianap olis, 1 997 . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Systems, Inc. • Cisco Park hu rst , W illiam

R., and Dav id R. Jackson. Pr act ical BGP for I nt er net Rou t in g . Cisco Pr ess: I ndian apolis, in p ress. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

• BGP4 Case St udies/ Tut or ial Sect ion 1 , ht t p: / / w w w . cisco.com / w ar p/ cust om er / 4 59/ 1 3. ht m l I SBN: 1- 58 705 -1 19 -2

Pages: 11 28

• BGP4 Case St udies/ Tut or ial Sect ion 2 , ht t p: / / w w w . cisco.com / w ar p/ cust om er / 4 59/ 1 4. ht m l • BGP4 Case St udies/ Tut or ial Sect ion 3 , ht t p: / / w w w . cisco.com / w ar p/ cust om er / 4 59/ 1 5. ht m l The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ialCase an d cu t t ing- edg echSect nologies. • BGP4 St udies/ Tut e ortial ion 4 , ht t p: / / w w w . cisco.com / w ar p/ cust om er / 4 59/ 1 6. ht m l ConCase cise ov v iewTut s ofort ial echn olog ies5 essen t own. cisco.com et wor k ing/ w prar ofession alserat/ 4all els, f rom • BGP4 St er udies/ Sect ion , ht t p: t/ ial / ww p/ cust om 59/lev 1 7. ht m l nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 42. Enhanced IGRP Obj e ct i ve s • •

Table of Content s

I dent if y t he f our k ey t ech nologies emp loyed by En hanced I GRP ( EI GRP) . I ndex

I nt e rn Under et w or k st ingand Te chnologie sH a ndbook Four th Edit t he Dif fu sing Upd,at e Algor ition hm By Cisco oper Systems, at ionalInc. ef ficiency

( D UAL) , and descr ibe h ow it im p rov es t he

of EI GRP.

Lear n how t o use EI GRP t o int ercon nect net w or ks w it h dif fer en t r out in g p r ot ocols as well as dif fer en t r out ed pr ot ocols.

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

I SBN: 1- 58how 705 -1it 19is -2 p ossible t o m ig r at e gr adu ally t o EI GRP. Discover Pages: 11 28

The Enhan ced I nt er ior Gat ew ay Rout in g Pr ot ocol ( EI GRP) repr esen t s an ev olut ion fr om it s pr edecessor I GRP ( ref er t o Ch apt er 44 , " I nt er ior Gat ew ay Rou t ing Pr ot ocol" ) . This evolu t ion r esult ed fr om chan ges in net w ork ing and t h e dem ands of d iver se, lar ge- scale in t er net w or k s. En hanced I GRP int eg rat es t h e capabilit ies of lin k- st at e p r ot ocols in t o dist ance v ect or pr ot ocols. Add ituion ally GRP ainbsest sev- selling eral imp orint ant pr ot ocols hat rgr ly in pcrrov ease it scover oper age at ional The pdat ed, EI edit ion cont of t he allone net w orkting ef eat erence ides of eff iciency r elat iv e t o ot her r out ing pr ot ocols. One of t hese pr ot ocols is t he Dif fu sing upd at e essent ial an d cu t t ing- edg e t ech nologies. algorit hm ( DUAL) d ev eloped at SRI I n t er n at ion al by Dr . J. J. Gar cia- Lun a- Acev es. DUAL enab les EI GRP r out er s t o det er m ine w het h er a pat h adv er t ised by a neighb or is looped or loop- fr ee, and allow sCon a rcise out er unv ning t oolog findies altessen er natteialpat wwor it hou t w ait ing on upd omels, ot h fer ovrer iew s EI of GRP t echn t ohs n et k ing pr ofession als at atesallfr lev rom r out ernov s. ice t o ex pert . En hanced I GRP er p rov ides com pat ibilit seam int erop at ion w itEAP h I GRP r out er s. An New chapt s include cov erag e yofand im por t antless t opics like er VoI P and aut om at ic- r ed ist r ibu t ion m echanism allow s I GRP rou t es t o b e imp or t ed int o En hanced I GRP, and v ice vCov er sa, erag so eitofis cut p ossible t ing edge t o add t echn Enh ologies anced lik I GRP e optgrical adunally et wor in tkoing an and ex iststing or age I GRP net w or k. Becau se t he m et r ics f or bot h p rot ocols ar e dir ect ly t ran slat ab le, t hey ar e as easily com par able as h ored stin ems, or tldw inomou net w sorsyst kingem f ors (t he I n.t er et . ion, if t heyAut w ere rouby t esCisco t hat Sy orig at edwin heiride owleader n aut on ASs) I nnaddit En hanced I GRP t r eat s I GRP r out es as ex t er nal rou t es and pr ov ides a w ay f or t he net w ork I n t ern et wr at oror k intgo Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat adm inist cu st omize t hem. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. ererv m s,iew conofcep t s,basic t echnoperat ologies, d devices used in act t oday netofw ork ing This chap t er prMast ov ider est he an tov t he ionan s and pr ot ocol char erist' sics indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . En hanced I GRP. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Enhanced IGRP Capabilities and Attributes Key capabilit ies t hat dist in guish Enh anced I GRP fr om ot her r out ing pr ot ocols include f ast conv er gence, sup por t f or v ariab le- lengt h sub net m ask, su ppor t for p art ial upd at es, and su ppor t for m ult iple net w or k layer p rot ocols. •

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•A r ou t er ru nning I ndexEnhan ced I GRP st or es all it s n eigh bor s' rou t ing t ables so t h at it can qu ick ly Iadap nt e rntett w k ing , Four o or alt er nTe atchnologie e r out es.s HI fa ndbook n o ap pr oprth iatEdit e r ion out e ex ist s, Enhan ced I GRP q uer ies it s n eig hbor s t o discover an alt ern at e r out e. These qu er ies pr opag at e unt il an alt er nat e rou t e is fou nd. By Cisco Systems, Inc.

I t s supp or t f or v ariable- lengt h subn et m asks p er m it s r out es t o be au t om at ically sum m ar ized on Pub lish er: Cisco Press a n et wor k n um ber bou ndar y . I n addit ion, Enh anced I GRP can b e config ur ed t o su m mar ize on e: Separy tem ber 1, 2 003 any Pub b itDat b ound at 1any in t er f ace. I SBN: 1- 58 705 -1 19 -2

En hanced Pages:I GRP 11 28 d oes n ot m ak e per iodic up dat es. I n st ead , it sends par t ial up dat es only w hen t he m et ric f or a rou t e chang es. Pr opag at ion of p ar t ial upd at es is aut om at ically boun ded so t hat only t hose r out er s t h at n eed t he inf or mat ion ar e up dat ed. As a r esu lt of t hese t w o cap abilit ies, En hanced I GRP consum es signif icant ly less ban dw idt h t han I GRP. En hanced I GRP includ es su ppor t for Ap pleTalk , I P, an d Nov ell Net W are. Th e AppleTalk The u pdat editrion ofrib t he b est - selling in-frone ork ing erence p rov age of im plem ented at ion edist ut es r out es learalln ed om net t hewRou t ingr ef Table Maint enides ancecover Pr ot ocol essent ial an d cu t t ingedg e t ech nologies. ( RTMP) . The I P im p lem ent at ion r ed ist r ibut es r ou t es lear ned fr om OSPF, Rout ing I nf orm at ion Pr ot ocol ( RI P) , I nt er m ediat e Sy st em - t o- I nt er m ed iat e Syst em ( I S- I S) , Ex t er ior Gat ew ay Pr ot ocol ( EGP)Con , or cise Bor der ews ay ot ocol . Thet ial Nov entpr atofession ion r ed ist r ibu es lev rouels, t es f rom ov erGat v iew of Pr t echn olog( BGP) ies essen t oell n etimp worlem k ing als at tall learn ed f rom Novell RI P or Ser v ice Adv er t isem ent Pr ot ocol ( SAP) . nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Underlying Processes and Technologies To p r ovide su perior r ou t in g perf or man ce, Enhan ced I GRP em ploy s f our k ey t ech nologies t hat com bine t o diff erent iat e it fr om ot her r out ing t echnologies: neigh bor d iscover y / recov er y , r eliable t r anspor t pr ot ocol ( RTP) , DUAL f init e- st at e mach in e, and pr ot ocol- dependent m odules. •

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•The neighbor Idndex iscover y/ recover y m echanism enables r out er s t o dy nam ically learn ab out ot her Ir nt e rn or kting chnologie sH a ndbook , Four EditRout ion er s also m ust d iscov er wh en t h eir n eig hbor s out eretswon heirTedir ect ly at t ach ed net w orthks. becom e unr each able or in operat iv e. This p rocess is ach iev ed w it h low ov erh ead by period ically By Cisco Systems, Inc. sen ding sm all hello pack et s. As lon g as a r out er r eceiv es hello packet s f r om a n eig hbor ing r out er , it assum es t hat t he n eig hbor is fun ct ion in g, an d t he t w o can exch ange r out in g Pub lish er: Cisco Press inf orm at ion. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705t -1Pr 19ot -2ocol ( RTP) is responsible f or gu aran t eed, ord er ed deliv er y of Enh anced Reliable Tr anspor I GRP packet Pages: 11 s 28 t o all n eigh bor s. I t sup por t s int er mix ed t ran sm ission of m ult icast or u nicast pack et s. For ef ficiency , only cer t ain Enhan ced I GRP packet s ar e t r ansm it t ed reliably . On a m ult iaccess net w or k t hat has m u lt icast capab ilit ies, such as Et her net , it is not necessary t o sen d hello pack et s r eliably t o all neigh bor s indiv idually . For t hat r eason, Enh anced I GRP sen ds a single m ult icast hello p ack et cont ain in g an in dicat or t hat infor m s t h e r eceiver s t hat t he p acket need ot bed e ackn owledg ed .bOt t yp esallof inp acket es, in dicat e in tcover he pack The u npdat edit ion of t he esth-er selling one s, netsuch w orkas ingupd r efat erence p rov ides ageetoft h at ackn ow ledg m en t is r equir ed. RTP cont ains a pr ov ision for send in g mu lt icast packet s q uick ly essent ial an d cu t t ing- edg e t ech nologies. w hen unack now led ged packet s ar e p en ding, wh ich helps en su re t hat con ver gence t im e r em ains low in t he p r esence of var y ing speed link s. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The DUAL f in itt oe-ex st at em nov ice pert . achine em bod ies t h e decision pr ocess f or all r out e com pu t at ions b y t r acking all r out es ad ver t ised by all neighb ors. D UAL uses dist ance inf orm at ion t o select efficient , loop- fNew ree pchapt at hs er ansdinclude select s cov r outerag es feorofinsert ion in at opics r out inlike g t able on f easible successor s. A im por t ant VoI Pbased and EAP feasib le successor is a neighb or in g rou t er used f or pack et for w ar ding t hat is a least - cost pat h t o a d estCov inaterag ion e t hof at cut is gt ing uar ant edge eedt echn n ot tologies o be p art lik eofopt a rical ou tninet g wor loopk ing . When and astnoreig age hbor ch anges a m et ric, or w h en a t opology chan ge occur s, DUAL t est s f or feasible successors. I f one is foun d, h ored Cisco Sy st pu ems, idee leader in netily w.orWking I n t ersuccessor n et . DUALAut uses it t oby avoid r ecom t in gw tor heldw r out unn ecessar hen fnoro tf he easible s ex ist bu t n eigh bor s st ill adv ert ise t h e dest in at ion, a r ecom put at ion ( also k now n as a diff using Icom n t ern etat wion or k)inmg ust Tech nologies Hand t h ccessor Ed it ion., Alt is ah ough com prr ecom ehensive ence put occur t o det er mbook in e a, nFour ew su pu t atrefer ion is not t hat enables net w ensive, or kin g pitr ofessionals o un derst andt im an e, d im t cont em por ar intoid er net w ork ing y pr ocessor - int does aff ect t conv er gence soplem it is en adv ant ageous t oyav u nnecessar Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing rt echnologies. ecom pu t at ions. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet edependent w it h new an d u pdatar ede chapt ersib s on secur y ,orstkorlay age, opt w or k inr g, scalabilit Pr ot ocolm odules r espon le for n etitw er pr otical ocol-net specific equir ement y, s. and Ispeed, t h ced is book is mod a com plet e an d u ple, p- t o-isd at e r ef er ence t o sending t he t op ics areing essen t o all The P- Enhan I GRP ule, for ex am r espon sib le for an dt hat r eceiv Enht ial anced w orpacket kin g psrof essionals, r egarlat dless ex pert ise. Inet GRP t hat are encapsu ed inofI P. Lik ew ise, I P- Enhan ced I GRP is also r espon sible f or par sing Enh anced I GRP pack et s and infor m ing DUAL of t he n ew in for m at ion t hat has been Reader s wIill obt ain ced a g reat er ask un der an ding of eLAN n ets, w or k ing, p ars t of icuwlar ly t hare e r eceived. P- Enhan I GRP s D st UAL t o mak r outand in g WAN d ecision t he r esult hich har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov idedned on st or ed in t he I P rou t ing t able. I P- Enh anced I GRP is r esp onsib le for r edist r ibut ing r out es lear a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions by ot her I P r out ing p rot ocols. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Routing Concepts En hanced I GRP r elies on f our f und ament al con cep t s: neighb or t ables, t opolog y t ables, rou t e st at es, and r out e t ag ging. Each of t hese is su mm ar ized in t he d iscussions t h at f ollow . •

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•

I ndex

Neighbor Tables I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

When a r out er discov er s a new n eigh bor , it record s t he neig hbor ' s add ress and int er face as an ent r y in t he neighbor t able. One neighb or t able ex ist s for each pr ot ocol- d ep en dent m odule. Pub lish When a ner: eigCisco hborPress sends a hello p ack et , it adv er t ises a hold t im e, w hich is t h e am ount of t im e Pub Dat e: Sep 2 003 or as r each able and oper at ional. I f a hello packet is not receiv ed t hat a rou t er t rtem eatber s a1 1,neighb I SBN: 158 705 -1 19 -2 w it hin t he h old t im e, t h e hold t ime ex pir es and DUAL is in for m ed of t h e t opology ch ange. Pages: 11 28

The n eig hbor - t ab le en t ry also in clu des inf orm at ion r eq uir ed by RTP. Sequence n um bers are emp loyed t o m at ch ackn owledg ment s w it h d at a p ack et s, and t he last sequ en ce num ber r eceiv ed fr om t he neigh bor is r ecor ded so t h at out - of- or der p ack et s can b e det ect ed . A t r an sm ission list is used t o qu eu e pack et s for p ossible r et r ansmission on a per- n eig hbor basis. Round - t r ip t im ers ar e k ep t in t he n eig hbor - t ab le en t ry t o est imat e an op t imal r et r ansm ission int er val. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Topology Tables Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice ttoabex The t opology lepert con.t ain s all dest inat ions adv er t ised b y neighb oring r out er s. The p rot ocoldepend en t m odu les p opulat e t he t ab le, an d t he t able is act ed on by t h e DUAL f init e- st at e New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP m achine. Each en t r y in t he t op olog y t able includ es t he dest inat ion add ress and a list of neighb or serag t hate hav e adv ised t techn he dest inat ion. eachn et neighb or, and t he ent r ecor d s t he Cov of cut t ingert edge ologies lik e For opt ical wor k ing st orr yage adv ert ised met r ic, w hich t h e neighb or st or es in it s r out in g t able. An im por t an t r ule t h at d ist an ce v ect orAut p rhotored ocolsbymCisco u st follow is t hat if ldw t h e ide neighb or adv ertw ises t his fdorestt he inatI nion Sy st ems, w or leader in net or king t er, nitetm . ust use t he r out e t o for w ar d packet s. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat The m et rnet ic twhat t heg rou t er uses t o t roeach t h e and destan in at is also t heerdnet estwinat enables or kin p r ofessionals un derst d ion im plem en tassociat cont emed porwarityh int orkion ing. The m et r ic t hat t he rou t er uses in t h e r out ing t able, an d t o adv ert ise t o ot her r out er s, is t he sum t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing of t he best ad ver t ised m et ric f r om all neigh bor s and t he lin k cost t o t he best n eig hbor . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kinStates g p rof essionals, r egar dless of ex pert ise. Route Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e A t opology - t able ent r y f or a d est inat ion can ex ist in one of t w o st at es: act iv e or passiv e. A har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on dest inat ion is in t he passiv e st at e w h en t h e r out er is not per for m in g a r ecom pu t at ion; it is in t he a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions act iv e st at e w h en t h e r out er is per for m ing a r ecom pu t at ion. I f f easible successor s ar e alway s t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . av ailab le, a dest inat ion never h as t o g o int o t he act iv e st at e, t her eby av oiding a r ecomp ut at ion. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich A r ecomp ut at ion occu rs w hen a dest in at ion has no feasible successors. Th e r out er init iat es t he pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease r ecom pu t at ion b y sen ding a q uer y packet t o each of it s neig hbor ing r out er s. The n eigh bor ing pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient r out er can send a reply p ack et , ind icat in g t h at it has a feasible successor for t he dest inat ion, or decisions for t h eir net w ork s. it can sen d a qu er y p ack et , indicat ing t h at it is par t icip at ing in t h e r ecom put at ion. Wh ile a dest inat ion is in t he act ive st at e, a r out er cannot chang e t he d est inat ion 's r ou t ing- t ab le inf orm at ion. Aft er t h e r out er has r eceiv ed a r ep ly fr om each n eigh bor ing r out er, t he t op ology t able ent ry f or t h e dest in at ion ret ur n s t o t h e passive st at e, an d t he r out er can select a successor .

Route Tagging En hanced I GRP sup por t s int er nal an d ex t ern al r out es. I nt er nal r out es or iginat e w it h in an En hanced I GRP AS. Th er efor e, a direct ly at t ached net w or k t hat is con figu r ed t o ru n Enhan ced I GRP is consid er ed an in t er nal r out e and is p rop agat ed w it h t h is infor m at ion t hr oug hout t he En hanced I GRP AS. Ext er nal rou t es are lear ned by an ot her r out ing pr ot ocol or reside in t he r out ing t ab le as st at ic r out es. These rou t es are t agged indiv idually w it h t he id en t it y of t heir •or igin. Table of Content s •

I ndex

I nt teer rn nal et w or k ing chnologie s Ha th Edit Ex r out esTear e t ag ged wndbook it h t h e, Four follow ingion infor m at ion: By Cisco Systems, Inc.

Rou t er I D of t h e Enh anced I GRP r out er t hat r edist ribu t ed t h e r out e Pub lish er: Cisco Press Pub AS Datne:um Sep ber tem of ber t1he 1, 2dest 003 in at ion I SBN: 1- 58 705 -1 19 -2

Con figu rab le adm inist rat or t ag Pages: 11 28 I D of t he ext er nal pr ot ocol Met r ic fr om t h e ext er nal p r ot ocol f lags f or ion defau r out in g- selling all- in- one net w ork ing r ef erence p rov ides cover age of The uBit pdat ed edit of lt t he b est essent ial an d cu t t ing- edg e t ech nologies. Rou t e t agg in g allow s t h e net w or k adm inist r at or t o cu st om ize r out in g an d main t ain f lex ible policy cont r ols. Rout e t aggin g is p art icular ly usefu l in t ran sit ASs, w here Enh anced I GRP t y pically int er act Con s cise w it h ov anerint v iew er dom s of ain t echn rouolog t ingies pressen ot ocolt ial t h at t o im n etplement wor k ings m pr ore ofession g lobal alsp at olicies, all levr esult els, fing romin a v er ynov scalable, ice t o expolicy pert . - based r out in g. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Enhanced IGRP Packet Types En hanced I GRP u ses t h e follow ing packet t y pes: hello and ack now led gm en t , up dat e, and q uery and r eply. •Hello p acket sTable Content ar e of m ult icasts f or neighb or discov er y/ r ecov er y and do not requ ire ack now ledgm ent . •An ackn ow ledgm I ndex ent p acket is a hello pack et t h at h as no dat a. Ack now led gm en t p ack et s cont ain Iantneonzer rn et w or ing Te chnologie s Ht an ndbook , Four Editays ion are sent by u sin g a unicast ad dr ess. o kackn ow led gm en um ber andthalw By Cisco Systems, Inc.

Updat e p acket s ar e used t o conv ey r eachab ilit y of d est inat ion s. When a new n eig hbor is discover ed , un icast updat e packet s ar e sent so t hat t he neig hbor can bu ild u p it s t opology t ab le. Pub lish er: Cisco Press I n ot her cases, such as a link - cost chang e, upd at es are mu lt icast . Upd at es alw ay s ar e Pub Dat e: Sep tem ber t r ansm it t ed r eliab ly.1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Qu er y Pages: and r11 eply 28 pack et s ar e sent w hen a dest inat ion has n o f easible successor s. Qu er y p acket s ar e alw ays mu lt icast . Rep ly packet s ar e sent in r esp onse t o q uer y packet s t o inst r uct t he or iginat or n ot t o r ecom pu t e t he r ou t e because feasib le su ccessor s ex ist . Reply p acket s ar e un icast t o t h e orig in at or of t h e quer y. Bot h quer y and r ep ly packet s ar e t ran sm it t ed reliably . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary Cisco Sy st em s's EI GRP is one of t he most feat ur e- r ich and r obust r out ing pr ot ocols t o ev er be dev elop ed . I t s un iq ue com binat ion of feat ur es blend s t he b est at t r ibut es of dist ance v ect or pr ot ocols w it h t he b est at t r ib ut es of link - st at e pr ot ocols. The r esu lt is a hy br id r out in g p rot ocol •t hat def ies easy Tablecat of eg Content orizats ion w it h con vent ion al pr ot ocols. •

I ndex

IEI ntGRP e rn et is w or k ing rTe chnologie H a ndbook , Four th Edit ion also emar k ablys easy t o conf igur e an d u se, as well as r em ark ably ef ficien t and secu re in operat ion . I t can be u sed in con jun ct ion w it h I Pv4 , AppleTalk, and I PX. Mor e im por t ant ly , it s By Cisco Systems, Inc. m odular archit ect ur e w ill r ead ily en able Cisco t o ad d su ppor t for ot h er rou t ed p rot ocols t h at m ay be d ev eloped in t h e fu t ur e. Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

Nam e t he f our key t echnologies t h at ar e used by EI GRP.

2:

I ndex Ex plain w hy EI GRP is m or e eff icient in op er at ion t han I GRP.

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : HowInc. d oes By Cisco Systems, 4:

RTP enab le im p rov ed conv er gence t im es?

Why does EI GRP t ag cer t ain rou t es?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Pep elnj ak , I van . EI GRP Net w or k Design Solu t ion s. I nd ianapolis: Cisco Pr ess, 2 000 . •

Table of Content s

•• Sp or t ack , Mark I ndex A. I P Rou t ing Fund am ent als. I nd ianapolis: Cisco Pr ess, 1 999 . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Inc. • htCisco t p: / /Systems, w w w . cisco.com / cpr ess/ cc/ t d/ cpr ess/ ccie/ nd cs79 8/ nd 201 7. ht m Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 43. IBM Systems Network Architecture Routing • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Descr ibe Class of Ser v ice, w hat it is, and h ow t o use it .

By Cisco Systems, Inc.

Descr ibe h ow t o use subar eas t o br eak u p t he net w or k . Pub lish er: Cisco Press

Descr h ow t o- peer Pub Dat e: ibe Sep tem berpeer 1 1, 2-003

r out ing w or ks.

I SBN: 1- 58 705 -1 19 -2

Descr ibe t yp es of Pt P r out ing . Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background I BM's net w ork ing ar chit ect u re has evolv ed consider ably as com put in g in g en er al h as ev olv ed aw ay f rom dom inat ion by cen t r alized comp ut ing solut ions t o peer - based com put in g. Today , I BM Sy st em s Net w or k Archit ect ur e ( SNA) rou t ing inv olv es t w o separ at e k inds of en vir onm ent s, •alt hou gh a n um Table of of Content ber k ey sconcept s ar e cent r al t o all SNA r out in g sit u at ion s. This chap t er •add resses f un I ndex ct ion s and ser v ices t h at m ak e bot h SNA sub area rou t ing and Adv anced Peer - t oIPeer nt e rnNet et w w oror k ing H a ndbook , Four th Edit ion cover ed in clud e session conn ect ions, k inTe g chnologie ( APPN) sr out ing p ossible. Topics t r ansm gr oups, ex plicit and v irt u al r out es, and Class of Serv ice ( COS) . Refer t o Ch apt er By Cisco ission Systems, Inc. 43 , " I BM Sy st ems Net w or k Ar chit ect u re Prot ocols, " f or gener al inf or mat ion abou t t r ad it ion al I BM SNAPub anlish d er: APPN. Figur e 43 - 1 illust r at es t he con cept s addr essed in t h is ch apt er in t he cont ex t of a Cisco Press t r adit ional SNA env ir on ment . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 4 3 -1 . SNA Rou t i ng Re li es on Tr a nsm issi on Gr oups t o I nt er con ne ct Su ba r ea En t it ie s The u pdat ed edit ion of t he b est - selling all[ View in-full onesize netimwage] ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IBM SNA Session Connectors I BM SNA session conn ect or s ar e used t o br idg e addr ess spaces w h en sessions t r av erse m ult iple add ress spaces. Th r ee t y pes of session connect ors ex ist : b ound ary f un ct ion s, SNA net w or k int er con nect ion ( SNI ) gat ew ays, an d APPN int erm ediat e r out in g f un ct ion s. Bound ary f un ct ion s •r eside in subar Table Content s m ap bet w een subar ea and p er ipher al ad dr ess spaces. SNI gat ew ays ea of n odes and •act as br id ges I ndex bet w een SNA n et wor k s, accept in g d at a f r om one n et w or k an d t r an sm it t ing it t o It he nt e rn et w opr or k ing s H ain ndbook Fournth appr iat eTedchnologie est inat ion anot,her etEdit w orion k . SNI gat ew ay s ar e t r anspar ent t o endp oint netCisco w or kSystems, at t achm ent unit s ( NAUs) . APPN in t er m ediat e nod es perf or m int er mediat e r ou t ing w it h in By Inc. APPN n et w or k s. Refer t o Figur e 43 - 1 f or t h e r elat iv e posit ion of a session conn ect or in a t r adit ional SNA env ir on ment . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IBM SNA Transmission Groups I BM SNA t r ansm ission gr oups ( TGs) ar e log ical conn ect ions for m ed b et w een ad jacent I BM SNA nod es t hat are u sed t o pass SNA session t r affic. TGs ar e com p rised of on e or m or e SNA link s and t heir assig ned t ran smission p rior it ies. Mult ilin k TGs, w hich pr ovid e added r eliabilit y and •ban dw idt h, are Table of Content used t o buns dle m ult iple p hy sical link s int o a sing le log ical SNA link . Mult ilink TGs •ar e supp ort ed I ndex only b et w een T4 n odes. TG sequence n um bers are used t o reseq uence out - ofIor ntder e rn et or k ing Te at chnologie s H a .ndbook th Edit ion pr iorit ies ar e supp ort ed at each t r ansm ission mwessages each hop Four ,t rFour ansm ission gr oup low , m edium By Cisco: Systems, Inc. , h ig h, an d net w ork - ser v ice t raf fic ( t he hig hest pr ior it y) . Refer t o Figur e 43 1 f or an illust rat ion of t h e r elat ionship of TGs w it h r esp ect t o ot h er com m on SNA r out ing comPub ponent s w it h in t h e cont ext of a sub ar ea rou t ing env ir onm ent . lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IBM SNA Explicit and Virtual Routes Rou t es bet w een su bar eas assu me eit her an ex plicit or v ir t u al r out e f or m. Ex plicit r out es ar e t he ph ysical connect ions bet w een t w o subar ea nod es, an d t hey ser v e as t he ord er ed sequ en ces of subar eas and connect ing t r ansm ission gr oups. Exp licit r ou t es are u nidir ect ion al, and t w o ex plicit •r out es ar e r eq Table of Content s e a full- d uplex pat h . uir ed t o cr eat •

I ndex

IVir nt et rn et w or k ing Te e chnologie s Ha ndbook , Four th Edit ual r out es ar t w o- w ay log ical con nect ionion s for m ed b et w een t wo subar ea nod es. A v ir t u al rByout e f low s over b ot h an ex plicit r out e an d a r ev erse ex plicit r out e t h at f ollow s t he sam e phy sical Cisco Systems, Inc. pat h . Vir t ual r out es d o n ot cr oss net w ork b ound ar ies; inst ead, t hey use an SNA n et w or k int er con nect session con nect or t o b rid ge t w o v ir t ual rou t es. Vir t ual rou t es include v alues def in ing Pub lish er: Cisco Press t r ansm ission pr iorit y an d global f low cont r ol, w hich is pr ovid ed by pacin g, in w hich a r eceiver e: Sep tem ber 1 1, 2 003 w it hPub suDat ff icient buf fer space gr ant s pacing w indow s t o t he sender . Each pacing w indow en ables I SBN: -1 19it-2a cer t ain am ount of infor m at ion befor e t h e send er mu st r equest t h e next t he send er t1-o58 t r705 ansm 11 28. Ref er t o Figur e 43 - 1 f or an illust rat ion of t h e r elat ionship bet w een ex plicit rou t es pacingPages: w indow and v irt ual r out es, and t h eir r elat ive p osit ion in t he cont ex t of an SNA su bar ea r out ing env iron ment .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IBM SNA Class of Service The I BM SNA Class of Ser v ice ( CO S) f un ct ion designat es t h e t r anspor t n et wor k char act erist ics of a g iven session . Depend in g on u ser r equir em en t s, diff er ent COSs can be sp ecified in an SNA net w or k. COS pr ovid es t he m ech anism t o d et er m ine all SNA rou t es and descr ibes accept able •ser v ice lev elsTable Content s. COS also specif ies t he collect ion of session char act er ist ics, in clud ing f or aof session •r espon se t ime, I ndex secur it y, and availabilit y . I n ad dit ion, COS can be est ablished aut om at ically w hen Iloggin nt e rn etgwin or,k or ing m Teanu chnologie , Four Edit ally ( sb Hy atndbook he user ) whthen t hion e session is in it iat ed. Each COS nam e is associat ed w itCisco h a list of v irtInc. u al r out es t h at m eet t he desir ed ser vice- lev el r eq uirem ent . Relevan t in for m at ion By Systems, for a g iv en session is capt u red in COS sub area and APPN t ab les. The diff er ences bet w een COS im plem ent at ion in subar ea and APPN rou t ing are su mm ar ized in t he follow ing sect ions. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

COSPages: in Subarea Routing 11 28 I n su bar ea r out ing , t he u ser d ef ines COS supp ort r eq uir ed f or a p art icular session. Specif ic v irt u al r out es ar e m apped t o id en t ified ser vices, wh ile COS ch aract er ist ics ar e associat ed wit h t he und er ly in g ex plicit r out es. The Sy st em Ser v ices Cont r ol Point ( SSCP) uses t he COS t ab le t o pr ov ide inf orm at ion on v ir t u al r out es and t r ansm ission pr iorit y t o t h e pat h cont r ol f unct ion. Pat h The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of cont r ol, in t ur n, select s a v ir t u al r out e an d t ran sm ission pr ior it y for use in a session. Figur e 43 - 2 essent ial an d cu t t ing- edg e t ech nologies. illust rat es t he subar ea r out in g COS t able- ent ry for m at . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Figu r e 4 3 -2 . A Suba r ea Rout in g CO S Ta bl e Hold s Da t a on Vir t ua l Rou t e s New chapt er s include covaerag of an im por t opics nd eTr smtiant ssion Prlike iorVoI i t iPesand EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Sub area rou t ing COS t able ent r ies inclu de COS nam e, v ir t ual r out e num ber ( VRN) , and subar ea t r ansm ission pr iorit y ( TRPI ) . COS nam e is a st andar d nam e, such as SEC3 , t hat is agr eed up on by conv en t ions.

The VRN ident if ies a specif ic rou t e bet w een sub areas. Up t o eight vir t u al r out e n um bers can be assig ned b et ween t w o subar ea n odes. Each v ir t ual rou t e can b e assign ed w it h up t o t hr ee dif fer en t t r ansm ission pr iorit ies, and up t o 24 v ir t u al r out es ar e possible bet w een t w o su bar eas. TPRI id en t ifies t he p r ior it y of logical u nit - t o- logical un it ( LU- t o- LU) session dat a f low ing over an exp licit rou t e. Users can select on e of t hr ee pr ior it ies f or each v irt ual r out e: 0 ( low est ) , 1, or 2 ( hig hest ) . •

Table of Content s

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I ndex

COS APPN Routing I nt e rn et in w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

COS in APPN is defin ed exp licit ly w it h COS t able p aram et ers. COS is m or e gr anu lar in APPN t han subar ea SNA. I n par t icular , COS for APPN allow s a r out e t o be defined based on capacit y, cost , Pub lish er: Cisco Press secur it y , pr op agat ion delay , an d user - def in ed char act erist ics. I t ext end s ser v ice t o end nodes Pub Dat e: Sep tem ber 1 1, 2 003 ( ENs) and is not lim it ed t o com m unicat ions cont r oller s, as in subar ea SNA. APPN COS per mit s I SBN: 1- 58 705 -1 19 -2t o main t ain a t r ee for ev er y COS t h at t r acks all r out es and cost s. APPN t he t opology d at abase Pages: COS also pr11 ov28 ides a conf igur at ion opt ion t o con t rol m em or y dedicat ed t o COS t r ees. Figur e 43 - 3 illust rat es t he APPN r out in g COS t able- en t ry for m at .

Figu r e 4ed3 edit -3 . ion AnofAPPN t in allg CO S Tabl I nerence cl udep rov Spe cia l Chage ar aofct er The u pdat t he b estRou - selling in- one net weorkCa ingn r ef ides cover essent ial an d cu t t ingRe edg t uer tns ech a nologies. n d Rout e - W ei ght in g I nf or m a t ion Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. APPN r out in g COS t able ent r ies in clu de COS nam e, ind ex , APPN t ran sm ission p rior it y ( TPRI ) char actserwist edding Field WF) .and WAN n et w or k ing, p ar t icu lar ly t h e Reader illics, obtan aind aAPPN g reatCOS er unWeig der sthtan of ( LAN har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on The COSr ang n ameeof is int a st and ame, such asices, SEC3, t h ating is ag vent s. quest ions a b r oad egr al ard sy stnem s and serv in clud detreed ailedupon descrby ipt con ion s, revion iew t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . The I n dex field ent r y enab les com pu t ed w eight v alu es for r out e com pon en t s t o be st or ed an d Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy r et riev ed . This ent r y p oin t s t o t he ent r y in t he COS w eight ar r ay w here t he w eight s for t h e COS syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich ar e st or ed . pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it yident an d ifies im prtov iciency, help he r eader in t elligent , costrou - efft e. icient APPN TPRI h eepreff iorit y of LUt o-ing LU tsession datm a ake flowmor ing eover an ex plicit It decisions for t h eir net w ork s. specif ies on ly one TPRI field f or each COS t ab le en t r y. APPN TPRI r equ ir es t hat t r aff ic ov er a giv en session w it h t he sam e COS in a par t icular APPN n et w or k f low w it h t he sam e t r ansm ission pr ior it y. Node an d t ran sm ission gr ou p ( TG) char act erist ics con sist of a user - sp ecified list of char act er ist ics accept able f or an ident if ied COS. Each r ow defines eit her a set of n ode

char act er ist ics or a set of TG char act er ist ics. Ent r ies can include secur it y, cost per connect t im e, and av ailab le capacit y. Th e field repr esen t in g a char act er ist ic cont ains a r ange of accept able v alues. The APPN COS WF enables r out es- select ion serv ices ( RSS) t o assig n a w eig ht t o a given possib le r out e com pon en t ( n ode or TG) . WF is used by RSS t o d et er m ine r elat iv e d esir abilit y of a par t icular r out e com pon en t . The WF can cont ain a con st ant or t he n ame of a fu nct ion t hat RSS uses in weigh t calcu lat ion. •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IBM SNA Subarea Routing SNA logical ar eas and nod e add ressin g ar e t w o cen t ral com p onent s of t r adit ional r out ing in SNA env iron ment s. This sect ion addr esses t h ese t op ics in t he con t ex t of t r adit ional SNA net w ork ing . •SNA n et w or kTable Content s ar eofdiv ided sin t o logical ar eas: subar eas and dom ains. Su bar eas con sist of a •subar ea n odeI ndex and it s at t ach ed per ipher als. Dom ains consist of a sy st em ser vices cont r ol poin t I( nt e rn et wand or k ing chnologie H a ndbook SSCP) t heTenet w ork sr esour ces ,tFour h at th it Edit canion cont r ol. SSCPs in d iff er ent dom ains can coop er at e w it h each ot her t o comp en sat e for h ost pr ocessor f ailu res. Figur e 43 - 4 illust r at es t he relat ionship By Cisco Systems, Inc. bet w een sub areas and d omain s in t he cont ex t of SNA sub ar ea rou t ing. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 705 .-1 Suba 19 -2 FiguI SBN: r e 14 58 3 -4 r e as Ex ist W i t h in Dom a in s in SNA Suba r e a Rout in g Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions t h eir w ork s. Node ad drfor esses ar net e cat eg orized as subar ea- node and perip heral- n ode add resses. Su bar ea- n ode add resses ar e g lob al and m ust be un ique w it h in t h e ent ir e net w ork . Th ese ad dr esses are assig ned t o NAUs w hen act iv at ed. Sub area- n ode add resses g en er ally consist of a sub ar ea por t ion and an elem en t p ort ion . All NAUs w it hin a giv en sub ar ea sh are t he sam e subar ea add ress bu t h ave d iff er ent elem en t add r esses.

Perip heral- n ode add resses, w hich ar e con sid er ed local ad dr esses, diff er dependin g on w het her t he node is T2 or T2 . 1. T2 add resses r efer t o NAUs and are st at ically assig ned, w hile T2. 1 add resses ar e d yn amically assign ed f or t he dur at ion of a session and ident ify t he session rat h er t han t h e NAU. Per iph er al- nod e addr esses ar e r ef err ed t o as local f or m- session ident ifier s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IBM Advanced Peer-to-Peer Networking Routing I BM Ad van ced Peer - t o- Peer Net wor k ing ( APPN) r out in g is dy nam ic and is based on a least w eig ht pat h calculat ed fr om in put r eceived fr om all APPN net w ork nodes. Each APPN net w or k nod e is r espon sib le for r epor t ing chang es in it s local t op olog y ( t hat is, t he n ode it self an d t he •at t ached lin ks) Table of Contentinf s or mat ion is passed u nt il all APPN nodes r eceiv e it . Wh en a node . Topology •r eceives d at aI ndex t h at it alr eady h as, it st ops for w ard ing t he d at a t o ot her nod es. D uplicat e Iinf nt orm e rn etat w ion or k ing chnologie a ndbook , Four Edit ion is Te r ecogn izeds vH ia a ch eck ofthu pdat e sequence n um ber s. Figur e 43 - 5 illust r at es w her e APPN w or k nInc. odes fit int o t he gener al scheme of an APPN en vir onm ent w it h ENs and low - en t r y By Ciscon et Systems, net w or k ( LEN) nod es. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Figu r e 4 3 -5 . APPN N et w or k N ode s Lin k t o ENs, LENs, a nd O t h er Pages: 11 28 Ne t w or k N odes

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is ing book is aions coman plet e an d ilit u p-ies t o-enable d at e r ef er ence t oing. t he These t op ics in t hat arenod essen ial 2t o.1all Sever al un derly fu nct d capab APPN r out clu de e t ytpe or kin g p rof essionals, r egar of ex rnet outwing , Depend en t Log icalUnitdless Request erpert / Serise. ver ( D LUR/ S) r ou t in g, conn ect ions net w ork s, and bor der n odes. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions IBM APPN Node Type 2.1 and Routing t o en su re con cept comp r eh en sion r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em Node t yp s, epr2. ovid 1 rou in gt ing a minv or eolvr ealist es r out ic ing pict tur r af e fic of bet t hewrealeen w onoreldorn m et w ore or kAPPN ing en net virwonm or k ent nods es. in w Tw hich o pr ofeessionals nod t y pe 2. 1 oper r outat ing e. pr Tools ocesses and ar gueidsupp elines ortfed: or opt intim er izing m ed iat syst e session em per for r out ming ance ( I SR) w ill incr and ease hig hpr odu per for ct miv ance it y an r out d im ingpr(ov HPR) e eff . iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Intermediate Session Routing The I SR p r ocess inv olves bin d session BI ND r equest s and r esp onses flow ing fr om n et w or k nod e t o net w ork node. I n t his env iron m en t , session conn ect or s ar e b uilt and u sed in p lace of r out in g

t ables in APPN. Wit h I SR, a map is g en er at ed of t he session id en t ifier and por t fr om on e sid e of a nod e t o t he ot her . A uniqu e session id en t if ier in t h e session conn ect or header is swap ped for an out g oing ident ifier and t h en is sent ou t f r om t he appr opr iat e por t . I SR- supp or t ed subar ea SNA feat ur es include n ode- t o- nod e err or an d f low - con t r ol pr ocessing, as w ell as session sw it ching ar ound net w or k f ailu res. Node- t o- n ode err or an d flow - cont r ol pr ocessing ar e consid er ed redu ndan t an d u nnecessar y because t hese pr ocesses redu ce end - t oend t hr oug hpu t . •

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High-Performance Routing By Cisco Systems, Inc.

The HPR pr ot ocol, an alt ern at ive t o I SR, is b ased on t w o k ey com p onent s: Rapid- Tr anspor t lish er: Cisco Press Pr otPub ocol ( RTP) and Aut om at ic Net w or k Rout in g ( ANR) . RTP is a r eliable, con nect ion - or ient ed Pub Datt e: Sepensur tem beres 1 1,deliver 2 003 y and m anages end - t o- end net w or k er r or and f low cont r ol. RTP pr ot ocol h at I SBN: 158 705 -1 19 -2 creat es new rou t es follow in g a net w or k failur e. ANR is a conn ect ionless ser v ice t hat is r esponPages: sib le 11 for 28 n ode- t o- nod e sour ce- r out ed ser v ice. The RTP lay er is inv oked only at t he edg es of an APPN net w ork . I n int er mediat e n odes, only t h e ANR lay er is inv ok ed . RTP nodes est ablish RTP connect ions t o carr y session dat a. All t raf fic f or a single session flow s ov er t he sam e RTP- t o- RTP conn ect ion and is m ult iplexed w it h t raf fic f r om ot her sessions usin g t he sam e connect ion. Figur e 43 - 6 illust r at es t he over all ar ch it ect ur e of an The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of HPR- b ased r out ing env ir on ment . essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

Figu r et o4ex 3 -6 . .RTP I s Su ppor t e d O n ly i n APPN Ed ge Ne t w or k Nod es nov ice pert New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions A yp su ical r out ing p rocess inv olv es rsev eral st ages. Firdit stional , a r ou t e isr ces select is using t o t en reHPR con cept comp r eh en sion and et en t ion, and ad r esou f oredfuwrthile her it st udy . ICov SR.erag To est ab lish a conn ect ion bet w een t he ed ge RTP nodes, eit her an ex ist ing RTPt oRTP e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy connect used a or r out ser vicices eqeuest ( RSR) r etkuing r ned out e- serv reply syst em s,ion pr is ovid in g or am e reealist pictr ur of t he real-iswsent or ld. nTh et ew or enrvir onm ent sices in w hich (prRSP) carr ies infor m at ion show ing for w ar d an d r ev er se pat h s t hr oug h t he net w or k . of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Pat hs repr esen t t h e for w ar d an d rev er se por t list s an d in clu de t he por t ident if ier used in each decisions for t h eir net w ork s. ANR node. Th ese list s ar e car r ied on ever y m essage, elimin at ing t he n eed for r ou t ing t ables or session con nect or s in t he ANR n odes. HPR pr ovid es f or link - failur e r ecover y. I f a lin k fails an d an alt er nat e p at h ex ist s bet w een t he RTP en dpoin t s for a par t icular COS, a n ew RTP- t o- RTP conn ect ion can b e select ed, and a session can be m oved w it hout disr upt ion . I f a connect ion does not ex ist along t h e new pat h, RSR an d

RSP m essages ar e sent t o obt ain t he n ew por t list s. Sending a new BI ND is n ot r equir ed b ecau se t he session is not disr upt ed. Flow cont r ol in an HRP env ir onm en t u ses a t echn ique called ad apt iv e r at e- b ased ( ARB) flow cont r ol. ARB flow cont rol mon it ors and cont r ols t he am oun t of t r af fic int rod uced int o t he net w or k. Un der ARB flow cont r ol, t h e sen ding and r eceivin g RTP nod es ex chang e m essages at r eg ular int er v als. Tr af fic int r od uced int o t he n et wor k is m odif ied t o adapt t o net w ork con dit ions. •

Table of Content s

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I ndex

IBM APPN DLUR/S I nt e rn et w or k ing Te chnologie s Routing H a ndbook , Four th Edit ion By Cisco Systems, Inc.

The Dependent Logical- Unit Requ est er / Ser v er ( DLUR/ S) is an APPN feat ur e t h at allow s legacy SNA t r af fic t o flow on an APPN n et wor k . Pub lish er: Cisco Press

Pub DLUR/ Dat e: Sep 1 1, /2ser 003 v er r elat ionship is est ablish ed bet w een a Dependent Log ical- Unit Under S,tem a ber client I SBN: 158 705 -1 19 -2 Serv er ( DLUS) and a D ep en dent Logical- Un it Requ est er ( DLUR) . A D LUS is t y pically an Pages: 11228en t it y, and a D LUR is t y pically a r out er . A pair of LU 6 . 2 sessions is est ablished ACF/ UTAM4. bet w een t h e DLUR and DLUS. Th ese LU 6. 2 session s t r anspor t legacy SNA cont rol messages. Those m essages n ot r ecog nized in an APPN env iron m en t ar e encapsulat ed on t he LU 6 . 2 session. Messag es t hen ar e d e- encapsu lat ed by D LUR an d are p assed t o t h e leg acy SNA LU. The DLU session in it iat ion is t h en passed t o t he DLUS an d is p rocessed by t h e DLUS as leg acy t raf fic. The DLUS sended s aedit m essag o tbh est e app licat ion , annet d t hweork app hostpsends t he BI ND. , The u pdat ion ofe t the - selling all-host in- one inglicat r efion erence rov ides cover ageFinally of legacy SNA dat a flow s n at ively w it h APPN t r aff ic. essent ial an d cu t t ing- edg e t ech nologies.

cise ov er v iew s of t echnNetwork olog ies essen t ial t o n et wor k ing IBMCon APPN Connection

pr ofession als at all lev els, f rom

nov ice t o ex pert .

An I BM APPN connect n et wcov or kerag is aelogical const u sedlike t o VoI p r ovide New chapt er s ion include of im por t antr uct t opics P anddirect EAP conn ect iv it y bet w een APPN ENs w it hout t he con figu rat ion ov erh ead of def in ing dir ect con nect ion s bet w een ever yCov pairerag of ENs. I n tgener al, t he pr ocess of lik creat ing a n con nectkion et w or k st ar t s w hen a e of cut ing edge t echn ologies e opt ical et wor ing nand st or age LOCATE requ est is r eceiv ed fr om an EN. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . A n et wor k n ode ( NN) t hen is used t o locat e t he dest inat ion specif ied in t he LOCATE r eq uest . I f tI he n t ern NNetsees w or ktin h at g Tech t h e tnologies w o ENs (Hand sour ce book and , Four desttin h at Edion) it ionar , is e at a tcom ach ed pr ehensive t o t he sam refer e t rence anspor t hat t m enables ed ium net ( such w oras kinTok g p ren ofessionals Rin g) , a vt iro t un u alderst nod and e ( VN) an dis im u sed plem t oen conn t cont ectem t he port waroy en intdpoin er nettw s ork anding for t echnologies. m a connectMast ion er nett w heork t er. m Ths,e con NN cep def tins,est echn t he session ologies, pat an dh devices as a direct used con innect t oday ion' sfrnet omwEN1 ork ing to VN indut ost ry EN2 . Lear , and n how t hen ttor aff incor ic is por per atmit e int t ed er net t o fwlow or kin . g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

IBM APPN Border Node

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e A b or is an APPN en tvitices y t hat ult iple net w ork s inf t o or int er con Pr ided esenton ly , har dwder ar e,node pr ot ocols, and ser inv enables olv ed . Fumndam entAPPN al t ech nology mat ion nect is pr. ov bor imp lem ed in serv ACF/ices, VTAM d ing OS/det 400ailed . Bordescr der nodes r esp for a b rder oadnrodes ang earofe int egr al ent sy st emonly s and in an clud ipt ionar s, erev iewonsible quest ions tt yo ing dirreect or ies t opology dat abases oget herand f or ad connect ed rnesou et wor k s,f or andfu rrteb uilding en su con ceptand comp r eh en sion and r et ten t ion, dit ional r ces her st udyBI . ND rCov eq uest sepend arat es in t each etet wor k .k ing concep t s, but also t o old er , legacy eragset ois show also ext ede nrou ot tonly o newn n wor syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Wit bor der n oper odes,atte. opology an d gu d irect or y dat ases in NNs arem e redu cedmtance o sizes ed f or pr ofhessionals Tools and id elines f orab opt im izing syst per for w illr equir incr ease indiv idual subnet w or k s r at her t han t h e com p osit e n et wor k . I n addit ion, cr ossnet w or k session pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient s ar e r out edfor t hrt hough thw e ork bors. der nod e. Figur e 43 - 7 illust r at es t he posit ion of bor d er n odes decisions eir net ( ACF/ VTAM and OS/ 40 0 devices) in a m ult inet w or k APPN env iron ment :

Figu r e 4 3 -7 . Bor de r N odes ( ACF/ VTAM an d O S/ 4 0 0 D ev ices) Can

Con ne ct APPN N et w or k s

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Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: •

What ar e SNA session con nect ors used f or? Table of Content s

I ndex What is cr eat ed w hen a net w or k nod e det erm ines v ia t h e LOCATE r equest t hat t he I nt e rn et w or tkw ing chnologie H aendbook , Fourt th o Te end n odess ar at t ached o tEdit h e ion sam e m edium ? •

2:

By Cisco Systems, Inc.

3:

Tr ue or f alse: All NAUs wit h in a subar ea hav e t h e same elem en t add r ess.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 44. Interior Gateway Routing Protocol • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

I dent if y t he m et r ics t hat I GRP u ses t o com p are r ou t es.

By Cisco Systems, Inc.

Ex plain how an ad min ist r at or can inf lu en ce rou t e select ion. Pub lish er: Cisco Press

Under and mu1lt1,ipat h Pub Dat e: st Sep tem ber 2 003

r out ing.

I SBN: 1- 58 705 -1 19 -2

I dent if y I GRP's nat iv e st abilit y feat ur es. Pages: 11 28

I dent if y I GRP's t imin g m echanism s and exp lain t h eir p ur pose.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background The I n t erior Gat ew ay Rou t in g Pr ot ocol ( I GRP) is a r out ing pr ot ocol t hat w as developed in t h e m id- 19 80s by Cisco Sy st em s, I nc. Cisco's p rin cipal goal in cr eat in g I GRP w as t o pr ov id e a r obu st pr ot ocol f or r out ing w it hin an aut onom ou s syst em ( AS) . Su ch pr ot ocols ar e k now n as I nt er ior •Gat ew ay RouTable s t ing of Pr Content ot ocols. •

I ndex

I nt w or Te chnologie s H ap ndbook , Four Edit Gat ion ew ay Rou t ing Prot ocol w as t he Rout ing n et rn heetm id-k ing 1 980s, t he m ost opular I nt th er ior IBynfCisco orm at ion Pr ot ocol ( RI P) . Alt h ough RI P w as quit e u sef ul f or r out ing w it hin small- t o m oder at eSystems, Inc. sized , r elat iv ely h om ogeneous int er net w or ks, it s lim it s w ere bein g pushed by net w or k gr ow t h. I n par t icular , RI P' s sm all h op- count lim it ( 16 ) r est rict ed t he size of int er net w ork s; single m et r ic Pub lish er: Cisco Press ( hop coun t ) sup por t of on ly eq ual- cost load b alancing ( in all- Cisco net w or k s only ! ) d id n ot allow Pub Dat e: Sep tem ber 1 1, 2 003 for m uch r out in g flexibilit y in comp lex env ir onm en t s. The p opular it y of Cisco r out er s and t he 1- 58 705 -1 19 -2 r obust nI SBN: ess of I GRP encour aged m an y or ganizat ions wit h lar ge int er net w or ks t o r eplace RI P w it h I GRP. Pages: 11 28

Cisco's init ial I GRP im plem en t at ion w or k ed in I nt er net Pr ot ocol ( I P) n et wor k s. I GRP w as designed t o r un in any n et w or k env iron m en t , how ev er , an d Cisco soon por t ed it t o ru n in OSI Con nect ion less- Net w or k Pr ot ocol ( CLNP) n et w or k s. Cisco developed Enh anced I GRP in t he ear ly 19 t o im oveion t heofop er at ing- selling eff iciency GRP.net This chapt d iscusses I GRP's basicage design The90s u pdat edpredit t he b est all-of in-Ione w ork ing reref erence p rov ides cover of and im plement at ion . En hanced I GRP is d iscussed in Ch apt er 42 , " Enhan ced I GRP. " essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IGRP Protocol Characteristics I GRP is a dist ance v ect or I n t er ior Gat ew ay Pr ot ocol ( I GP) . Dist ance vect or r out in g p rot ocols m at hem at ically com par e r out es using som e m easur em en t of dist ance. This m easur em ent is k now n as t he d ist an ce vect or . Rou t er s u sing a dist ance v ect or p rot ocol mu st sen d all or a p or t ion •of t heir r out in Table ofle Content g t ab in a rsout ing - upd at e m essage at r eg ular int er vals t o each of t h eir •neighb or in g rou I ndex t er s. As r out in g in for m at ion p r olif er at es t h rou gh t he n et w or k , r out er s can Iident nt e rnifetywnew or k ing Te chnologie H a ndbook th ed Editt ion dest inat ionss as t hey ar, Four e add o t he n et w or k , learn of f ailu res in t he n et wor k , and , m ost imSystems, por t ant ly , calcu lat e dist ances t o all kn own d est inat ion s. By Cisco Inc. Dist ance v ect or rou t ing pr ot ocols are oft en con t r ast ed w it h lin k- st at e r ou t in g pr ot ocols, w h ich Pub lish er: Cisco Press sen d local conn ect ion inf orm at ion t o all nodes in t he in t er net w or k . For a d iscussion of Op en Dat e: Sep tem ber 1 1, 2 003 ShorPub t est Pat h First ( OSPF) an d I nt er m ed iat e Sy st em - t o- I nt er m ed iat e Syst em ( I S- I S) , t w o I 58at 705 19 -2ing algor it hm s, see Ch apt er 47 , " Open Sh ort est Pat h Fir st ," and Ch apt er pop ularSBN: link1-- st e -1 r out Pages:Sy 11 st 28em I nt ercon nect ion Rou t ing Prot ocol, " r espect iv ely. 48 , " Open I GRP uses a com posit e m et r ic t h at is calculat ed b y fact or ing w eig ht ed mat h em at ical v alues for int er net w ork delay , b andw idt h, r eliab ilit y , an d load. Net w or k ad min ist r at or s can set t he w eig ht ing f act or s f or each of t h ese m et r ics, alt hou gh gr eat car e should be t aken befor e any defau v alues ar eion m anipulat ed.- selling I GRP p allr ovides a wnet id ew ork r ange it s m et rpics. Reliabilit and of load, The u lt pdat ed edit of t he b est in- one ing for r ef erence rov ides covery age for ex am ple, can t ake on an y valu e bet w een 1 and 255 ; b andw idt h can t ak e on values r eflect in g essent ial an d cu t t ing- edg e t ech nologies. speed s fr om 1 200 b ps t o 10 Gbp s, w hile delay can t ak e on any v alue f r om 1 t o 2 24 . Th ese w ide m et ric r ang es are fur t h er com plem en t ed b y a series of user - definab le con st an t s t h at enable a net w or k adm or st oofint fluence r out select iont.o These st ant s ar e hash t hef rom Con cise inist ov errvatiew echn olog ies eessen t ial n et worcon k ing pr ofession alsed at against all lev els, m et rics, each ot h.er , in an algor it hm t h at y ield s a sing le, com posit e m et ric. Th us, t he nov and ice t o ex pert net w or k adm inist r at or can in fluence r out e select ion by g iving h ig her or low er w eig ht ing t o specifNew ic m et chapt r ics.erThis s include f lex ibilit cov y erag allowe sofadim mpor in ist t ant r at or t opics s t o fin like e- tVoI u neP Iand GRP'EAP s au t omat ic rou t e select ion. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age To p r ovide addit ional flexibilit y , I GRP per mit s mu lt ip at h rou t ing. Dual eq ual- band w id t h lin es can h ored by Cisco or ldw ide fleader or om kingatfic orsw t he I nover t er n et r un a Aut sing le st r eam of t rSy affst icems, in rouwndr obin ash ion ,inwnet it h waut it ch t o. t he second lin e if one line g oes dow n. Mult iple pat hs can hav e unequ al m et rics y et st ill be v alid mu lt ip at h rou t es. I n t ern et wple, or k inifgone Tech book Ed it ion ,h is com ence hatlow er) , For exam p nologies at h is t hrHand ee t im es b, etFour t er tthhan anot er apat h (pr it sehensive m et ric isrefer t hr ee t imtes netpat w or p r ofessionals and d imrplem por tar y int net w ork tenables he bet t er h kin w illg be u sed t hr ee ttoimun esderst as oft en.an Only out esenwt itcont h mem et rics hat ar er ew it hin a ing t echnologies. eriance t he t of er m t s,e t ar echn devices used t oday s nethwerork ing cer t ain r ange Mast or var t hs,e con bestcep r out e uologies, sed as man ultdiple p at hs. Varin iance is ' anot value ry . be Lear how ted o incor pornet at ewint net winist or kin t echn olog ies in t o a LAN/ WAN env ir onm ent . tindu hat st can estnablish by t he or keradm r atgor . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

Stability Features

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dwpr arov e, idpres ot a ocols, serfeat v ices invt hat olv ed ndam enttal t ech nology or mat is prinov ided I GRP nu mband er of ur es ar.eFu desig ned o enhan ce it s inf st abilit y.ion These clu de on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions holdd ow ns, split h orizon s, and poison- r ev er se u pdat es. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Hold dowensisaralso e u sed t o pr regut lar updnatetewor m essages f romt s, in appr opr iat einst at in g a Cov erag ext end edevnent ot only o new k ing concep but also t oely oldrer , legacy rsyst out em e t hs,atprmovid igh tinhgave one ad. Wh en ur a e rou ing en r out s det ect ishich via a mgor e r bealist ic pict oft er t hegoes real-dow w orn, ld neighbor n et w or k ing virer onm ent s int hw tpr heof lack of r egular ly e. schTools ed uled messages. r out erem s t hper en for calcu lat e new r outease es an d essionals oper at andu pdat gu ideelines f or optThese im izing syst m ance w ill incr sen d rou ing upd at eprmovessages t o in for m ing t h eirt he neig hbor smof t h emor r out e chan ge. ,This it y begins pr odu ct ivtit y an d im e eff iciency, help r eader ake e in t elligent costact - effivicient a w av e of for t r igg u pdat decisions t h er eirednet w orkes s. t hat f ilt er t hr ough t h e net w or k. These t rig gered upd at es do not inst ant ly ar r ive at ev er y n et w or k dev ice. Th us, it is p ossible f or a device t hat has yet t o be inf orm ed of a net w or k f ailu re t o sen d a r eg ular u pdat e m essag e, w hich ad ver t ises a failed r out e as b eing v alid t o a d ev ice t hat has j ust b een not if ied of t he net w ork failur e. I n t h is case, t h e lat t er dev ice w ou ld cont ain ( and p ot en t ially ad ver t ise) incorr ect r out in g in for m at ion. Holdd own s t ell r out er s t o h old d ow n an y chang es t hat m igh t af fect r out es f or som e per iod of t im e. The

holdd ow n p er iod usually is calcu lat ed t o be j ust g reat er t h an t he per iod of t im e n ecessar y t o up dat e t h e ent ir e net w ork w it h a r out ing chang e. Split hor izons d er iv e fr om t he pr em ise t h at it is nev er u sef ul t o sen d in for m at ion ab out a r out e back in t he d irect ion fr om w hich it cam e. Figur e 44 - 1 illust r at es t he sp lit - h or izon r ule. Rou t er 1 ( R1 ) ad ver t ises t h at it has a rou t e t o Net w or k A. Th er e is n o r eason f or Rout er 2 ( R2) t o includ e t his r ou t e in it s upd at e back t o R1 becau se R1 is closer t o Net w or k A. Th e split - hor izon ru le say s t hat R2 should st r ike t his r out e f rom any u pdat es t h at it send s t o R1. Th e split - hor izon ru le help s • Table of Content s pr event r out ing loops. Consider, for ex amp le, t he case in w h ich R1 's int er face t o Net w ork A goes • I ndex dow n . Wit hou t split h or izon s, R2 cont inues t o inf orm R1 t hat it can get t o Net wor k A ( t hr oug h I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion R1 ) . I f R1 does not hav e suf ficient int elligence, it act ually m ight pick up R2 's r out e as an By altCisco ern atSystems, ive t o it sInc. f ailed dir ect connect ion, causing a r out in g loop . Alt hou gh holddow n s should pr event t his, split hor izons ar e im plement ed in I GRP b ecause t h ey pr ovide ex t r a algor it h m st abilit y. er: Cisco Press Pub lish Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 4 4 -1 . Th e Spl it -H or iz on Rul e He lps Pr ot ect Agai nst Rou t i ng Loops

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Split hornet iz ons event r out ting loops eend adj acentenr tout er s, r ev erwseork ing enables w orshould kin g p rpr ofessionals o un derstbet andw an im plem cont embut porpoisonar y int er net up dat es ar e n ecessar y t o defeat lar ger r out in g loop s. I n cr eases in r out in g m et r ics g en erwally t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net ork ing indicat e r out in g loop s. Poison rev er se up dat es t hen ar e sen t t o r em ov e t he r ou t e and it in indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env irplace onm ent . holdd ow n. I n Cisco' s im plement at ion of I GRP, poisonr ever se updat es ar e sent if a r out e m et Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,r ic has cr eased a fact of 1.plet 1 ore gr and in speed, t h isbybook isor a com aneat d uerp-. t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Timers har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions It oGRP mre aincon t ains a num ber im er and s andr etv en ariables contad ainin g t imreesou in t er v als. in clu de an en su cept comp r ehof ent sion t ion, and dit ional r ces f orThese fu rt her st udy . up dat e t im er, an in valid t im er , a holdt im e p er iod, an d a f lu sh t im er. The up dat e t im er sp ecifies Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy how fr equent ly rinout g or updat e m essages should sent GRP lt vir for onm t hisent v arsiab is 90 syst em s, pr ovid g ain m e r ealist ic pict ur e of t hebe realw .orTh ld enIet w or defau k ing en in le w hich second s. The inv alid t im er sp ecifies how lon g a r out er shou ld w ait in t h e absen ce of rou t ingpr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease upodu dat ect m essages abprout specif ic r out e bing ef ore ingmtake hat mor r outee in inv alid. Th, ecost I GRP pr iv it y an d im ov ea eff iciency, help t hedeclar r eader t elligent - effdefault icient for tdecisions his v ar iable is t h ree t im es t he u pdat e period . The holdt im e v ariable sp ecifies t he holddow n for t h eir net w ork s. per iod. Th e I GRP d ef ault for t his v ariable is t hr ee t imes t h e upd at e t im er period plu s 10 second s. Finally, t he flush t im er in dicat es how m uch t im e sh ould pass befor e a r out e shou ld b e flushed fr om t he r out ing t ab le. The I GRP defau lt is sev en t imes t h e r out ing up dat e p er iod.

Summary I GRP has p rov en t o be one of t he most su ccessf ul r ou t ing pr ot ocols of all t ime. No small par t of it s success h as been d ue t o it s fu nct ional sim ilar it y t o RI P, a sim ple y et h ig hly successful and w idely deploy ed r out ing p rot ocol. Cisco t ook gr eat pains t o car ef ully pr eser v e m any of t he •eff ect iv e feat Table ur es of of Content RI P, wsh ile g reat ly ex pand in g it s cap abilit ies. Tod ay, I GRP is show ing it s ag e; •it lack s supp ort I ndex for var iable- len gt h subn et m ask s ( VLSM) . Rat her t han dev elop an I GRP ver sion 2 It o nt einrncor et wpor k ing chnologie s H ay, ndbook Edit orat e Te t hat cap abilit Cisco, Four hasthbu ilt ion up on I GRP's legacy of success w it h En hanced I GRP. En Cisco hanced I GRPInc. is ex amin ed in Ch apt er 42 of t his book . By Systems, Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

Nam e t he b en ef it s of using I GRP inst ead of RI P.

2:

I ndex can an adm inist rat or influence r out e select ion ? How

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : What By Cisco Systems, Inc.is 4:

v ar ian ce, an d h ow does it aff ect m ult ipat h r out ing ?

I dent if y and ex plain I GRP' s st abilit y feat u res.

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

What t im er s ar e u sed by I GRP, and w hat is t heir f unct ion?

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Sp or t ack , Mark A. I P Rou t ing Fund am ent als. I nd ianapolis: Cisco Pr ess, 1 999 . •

Table of Content s

•• I ndex ht /w . cisco.com / uns iv cd / cc/, tFour d / doc/ pr odu I ntt ep: rn/et ww orw k ing Te chnologie H er a ndbook th Edit ion ct / sof t w are/ ios113 ed / 113 ed _cr / np1 _c/ 1cigr p. ht m By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 45. Internet Protocol Multicast Obj e ct i ve s • •

Table of Content s

Ex plain I P m ult icast add ressin g. I ndex

I nt e rn Lear et w ornk ing H aer ndbook , Four Edit ion t heTebchnologie asics of sI nt net Gr ou pthManagem en t

Pr ot ocol ( I GMP) .

By Cisco Systems, Inc.

Ex plain how m u lt icast in Lay er 2 swit chin g w or k s. Pub lish er: Cisco Press

Defin e m ult icast dist rib ut ion t r ees.

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 58 705 19icast -2 Lear n 1how m-1 ult f orw ar din g w or k s. Pages: 11 28

Ex plain t he b asics of pr ot ocol- independ en t m u lt icast ( PI M) . Defin e m ult ipr ot ocol BGP. Lear n how Mu lt icast Sour ce Discov er y Pr ot ocol ( MSDP) w or k s. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essentEx ialplain an d rcu t t ing-m edg t ech: nologies. eliable ulteicast PGM. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background I n t ern et Pr ot ocol ( I P) m u lt icast is a ban dw idt h- con ser vin g t echn olog y t hat r ed uces t raf fic b y simu lt aneously deliv erin g a sin gle st r eam of in for m at ion t o t h ousands of cor por at e r ecip ient s and hom es. Applicat ions t h at t ak e ad van t age of m ult icast include videoconf er encing, cor por at e •com mu nicat ion Table of Content s, dist ance slearn in g, an d d ist r ibu t ion of sof t w are, st ock qu ot es, and new s. •

I ndex

I nt rn et or k ing Te chnologie s H atndbook th iple Edit ion P eMu lt w icast deliv ers sou rce r af fic t, oFour m ult r eceiver s w it hout add ing any add it ional b ur den on tBy heCisco sou Systems, rce or t he r eceiver s w hile using t h e least net w ork bandw id t h of an y comp et in g Inc. t echnology . Mu lt icast packet s ar e r eplicat ed in t he n et w or k b y Cisco rou t ers en abled w it h Pr ot ocol I ndepend en t Mu lt icast ( PI M) an d ot h er su ppor t ing m ult icast pr ot ocols r esu lt in g in t h e Pub lish er: Cisco Press m ost eff icient deliv er y of dat a t o m ult iple r eceiv er s p ossible. All alt er nat iv es requ ir e t h e sour ce Pub Dat e: Sep tem ber 1 1, 2 003 t o send m or e t han one cop y of t he d at a. Som e even r eq uire t he sour ce t o send an indiv idual 705 -1 19.-2I f t her e ar e t hou san ds of r eceiver s, even low- b andw idt h ap plicat ion s copy t oI SBN: each1- 58 r eceiver benefitPages: fr om11u28 sin g Cisco I P Mult icast . High- b andw idt h ap plicat ion s, su ch as MPEG video, m ay r eq uir e a lar ge p ort ion of t h e available n et wor k b andw idt h f or a sing le st ream . I n t hese app licat ions, t h e only w ay t o sen d t o m or e t han one r eceiv er sim ult an eou sly is b y using I P Mu lt icast . Figur e 45 - 1 d em on st r at es h ow dat a fr om on e sour ce is deliv ered t o sever al int er est ed r ecipient s u sin g I P m ult icast .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r e 4 5 -1 . M u lt ica st Tr a nsm issi on Se nds a Sin gl e M ul t icast Pa ck e t Con cise ov er v iew sAd of tdr echn olog iest o essen n et wor ing pr ofession essed All t Iialntt oen de d kRecipi en t s als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Multicast Group Concept Mu lt icast is b ased on t he concept of a gr ou p. An ar bit r ary gr oup of r eceiv er s ex pr esses an int er est in r eceiv ing a par t icular d at a st r eam. This gr oup does n ot h ave an y ph ysical or geogr aph ical boun dar ies—t he host s can b e locat ed any w her e on t he I nt er net . Host s t h at ar e •int er est ed in Table ofing Content r eceiv dat as flow ing t o a par t icular gr oup m ust join t he g rou p usin g I GMP. Host s •m ust b e a m em I ndex ber of t he g r oup t o r eceiv e t he d at a st r eam. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IP Multicast Addresses Mu lt icast addr esses sp ecify an ar bit r ar y gr oup of I P h ost s t hat hav e join ed t he gr oup and w ant t o r eceive t raf fic sent t o t h is gr oup . •

Table of Content s

•

I ndex

IP Class D Addresses I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

The I n t ern et Assigned Num bers Aut hor it y ( I ANA) con t rols t he assig nm en t of I P mu lt icast add resses. I t has assig ned t he old Class D ad dr ess sp ace t o be u sed for I P m ult icast . This m eans er:mCisco Press g rou p addr esses w ill fall in t h e r ange of 2 24. 0. 0. 0 t o 239 .2 55. 2 55. 25 5. t hatPub alllishI P u lt icast Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

NO TE This ad dr ess r ang e is only f or t he gr oup addr ess or dest inat ion addr ess of I P m ult icast t r aff ic. The sour ce addr ess for mu lt icast dat agr am s is alw ays t he u nicast sour ce The uadd pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of ress. essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t oLink ex pertLocal . Reserved Addresses New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP The I ANA has r eser ved addr esses in t he 2 24. 0 .0 .0 t h rou gh 22 4. 0. 0. 25 5 t o be u sed by n et wor k pr ot ocols on ae local w or k segt echn m en ologies t . Packetliks ewopt it h ical t hese shou n ev er be f or w ard ed Cov erag of cutnet t ing edge n etadd worresses k ing and stld or age by a r out er ; t h ey r em ain local on a p ar t icu lar LAN segm ent . Th ey ar e alw ay s t r ansm it t ed w it h a t im e- Aut t o- liv e ( TTL) of 1 . Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . h ored by Cisco Net w ork ocols u se t hese addr esses auttom at it icion r out iscov y an d t o refer comm u nicat I n t ern et wpr orot k in g Tech nologies Hand bookf,orFour h Ed , iseradcom prerehensive ence t hate im por t ant r out ing inf orm at ion. For ex am ple, OSPF u ses 22 4. 0. 0. 5 and 22 4. 0. 0. 6 t o ex chang e enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing link st at e inf or mat ion . Table 4 51 list s som e of t he w ellkn ow n ad dr esses. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

Tab le 4 5 - 1 . Lin k Loca l Ad dr esses

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har arss e, pr ot ocols, and ser v ices inv olv ed . Fu ndam Addw dre U saent geal t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o22en 4.su 0. re 0. 1con cept comp r eh en sion and r et en t ion, All andsyad st em dit ional s on rt his esou sub r ces netf or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy 22 4. 0.s, 0. 2pr ovid in g a m or e r ealist ic pict ur e of t heAll r out er ld s on his syst em realw or n ett w orsub k ingnet en vir onm ent s in w hich pr22 of4. essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease 0. 0. 5 OSPF r out er s pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient 22 4. 0. 0. 6for t h eir net w ork s. OSPF d esign at ed r out er s decisions 22 4. 0. 0. 12

Globally Scoped Address

DHCP ser v er / r elay agent

The r an ge of add resses f r om 22 4. 0. 1. 0 t hr oug h 2 38. 25 5. 25 5. 255 ar e called globally scoped add resses. Th ey can be u sed t o m u lt icast d at a b et w een org anizat ions an d acr oss t he I nt er net . Som e of t hese add resses h ave b een r eser ved for u se by m ult icast app licat ions t hr ough I ANA. For exam ple, 2 24. 0. 1. 1 has been r eser ved for Net w or k Tim e Pr ot ocol ( NTP) . Mor e inf or mat ion abou t r eser v ed m ult icast add resses can be f oun d at ht t p: / / w w w . isi. ed u/ in• Table of Content s not es/ iana/ assig nm ent s/ m ult icast - ad dr esses. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Limited Scope Addresses Pub lish er: Cisco Press

The r an ge of add resses f r om 23 9. 0. 0. 0 t hr oug h 2 39. 25 5. 25 5. 255 cont ains lim it ed scope Pub Dat e: Sep tem ber 1 1, 2 003 add resses or adm inist rat iv ely scoped add resses. These ar e defin ed by RFC 2 365 t o be I SBN: -1 19 -2 const r ain ed 1-t o58a705 local g rou p or org anizat ion. Rout er s ar e t y pically conf igur ed wit h f ilt er s t o Pages: 11icast 28 pr event m ult t r aff ic in t his add ress r ange fr om f low ing ou t sid e an aut onom ous sy st em ( AS) or an y user - d ef ined d om ain . Wit hin an aut on omou s syst em or d omain , t he lim it ed scope ad dr ess r ange can be fur t h er su bdiv ided so t hose local m ult icast boun dar ies can be d ef ined. Th is also allow s for ad dr ess r euse am ong t hese sm aller dom ains. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent an d cu t t ing- edg e t ech nologies. GlopialAddressing RFC 277 p r oposes t hat t he 23 3.olog 0. 0.ies 0/ 8essen ad dr tess be kr eser v ed f or st at ically d ef ined Con0cise ov er v iew s of t echn ial troang n etewor ing pr ofession als at all lev els, f rom add resses b y or ganizat ions t hat already h ave an AS num b er r eser v ed . The AS nu mb er of t he nov ice t o ex pert . dom ain is em b ed ded in t o t h e second and t h ir d oct et s of t he 2 33. 0. 0 .0 / 8 ran ge. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP For exam ple, t h e AS 6 2010 is w r it t en in hex as F2 3A. Separ at ing out t he t wo oct et s F2 an d 3 A, w e get 242 and 5 8cut int ing decimal. is wologies ould give a ical su bnet of 233 42. 58 0 age t h at w ou ld b e Cov erag e of edge Th t echn lik eus opt n et wor k ing.2and st .or globally r eser v ed f or AS 6 2010 t o use. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Layer 2 Multicast Addresses enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Nor net w k intt oerincor face por car at dse( int NI Cs) onw or a kin LANg segm onlyWAN p ackenv et s irdest indumally st ry . ,Lear n or how er net t echnent ologwill ies rineceiv t o a eLAN/ onmined ent . for t heir bu rn ed in MAC ad dr ess or t he br oad cast MAC ad dr ess. Som e m eans h ad t o be d ev ised Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, so at m ulttiple h ost siscould receiv t he e pd ack st ill tbo et he capt able dif fer t iat ing andt hspeed, h is book a com plet eean d usam p- t oat e et r efan er dence op icsoft hat areenessen t ialamon t o allg m ult icast gr oup s. net w or kin g p rof essionals, r egar dless of ex pert ise. Fort unat t he ain I EEE ions m ade rov isions f or t nhe t ran ission Reader s ely w ill, obt a gLAN reatspecificat er un der st an ding of pLAN and WAN et w or ksm ing, p ar t of icubr laroadcast ly t h e and / orarme,ultpricast packand et s. ser I n vt he and ard , bit ent 0 of st oct et t o is indicat a on har dw ot ocols, ices802 inv.3olvsted . Fu ndam al tthe echf irnology infisorused mat ion pr ov eided br an d/ or int m uegr lt icast r ame. Figurserv e 45 - 2 sh he locat ion of t heipt brion oadcast m ultquest icast ions bit a boadcast r oad r ang e of al syfst em s and ices, inows clud ting det ailed descr s, rev/iew in Etre hercon netcept f ramcomp e. r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . t o an en su Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Figu 5 -2 . I help EEEing8 0t he 2 .3 M AC Addmor r ess m a, tcost - eff icient pr odu ct iv it y an d im pr ov reeeff4iciency, r eader m ake e in tFor elligent decisions for t h eir net w ork s.

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Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

This By Cisco b it Systems, ind icat es Inc. t h at t h e fr am e is dest ined for an ar bit r ar y gr oup of host s or all host s on t he net w or k ( in t he case of t he b road cast addr ess, 0x FFFF. FFFF. FFFF) . Pub lish er: Cisco Press

I P m ult icast m ak es use of t his capab ilit y t o t r ansm it I P p ack et s t o a gr ou p of h ost s on a LAN Pub Dat e: Sep tem ber 1 1, 2 003 seg m en t . I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Ethernet MAC Address Mapping The I ANA own s a b lock of Et her net MAC add r esses t hat st ar t w it h 0 1: 00 : 5E in hexad ecim al. Half of t his b lock is allocat ed for m ult icast ad dr esses. Th is cr eat es t he ran ge of av ailab le Et her net The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of MAC add resses t o be 0 100 .5 e0 0. 00 00 t hr oug h 0 100 .5 e7 f. ff ff . essent ial an d cu t t ing- edg e t ech nologies. This allocat ion allow s f or 23 bit s in t h e Et h er net addr ess t o cor respon d t o t he I P m ult icast gr oup add ress. The m ing splaces t heolog lowies er 23 bit st ial of ttoh e I Pwor m ult icast gr oup adals dr ess intlev o tels, hesef rom Con cise ovapp er v iew of t echn essen n et k ing pr ofession at all av ailab le 23 bit s in t he Et her net ad dr ess ( show n in Figur e 45 3) . nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Figu Covrerag e 4 5e -3 of cut . Mt ing a ppi edge ngt echn of I ologies P M ul lik t i cast e opt ical t o nEt et wor he rk ne ing tand / FDD st orIage M AC Addr e ss Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Becau se t he up per 5 bit s of t h e I P m ult icast add ress ar e dr opp ed in t his m app ing, t he r esu lt in g add ress is not un iq ue. I n fact , 3 2 d if fer ent m u lt icast g r oup I D s all m ap t o t h e same Et her net add ress ( see Figur e 45 - 4) .

Figu r e 4 5 -4 . M AC Add r ess Am bi gu it i es •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Internet Group Management Protocol I GMP is used t o dy nam ically r egist er indiv idual host s in a m ult icast gr oup on a p ar t icu lar LAN. Host s ident if y gr oup m em b er ships b y sen ding I GMP messag es t o t h eir local m ult icast r out er . Under I GMP, rou t ers list en t o I GMP m essages and per iodically send out quer ies t o discover w h ich •gr oup s ar e act Table ive of orContent in act ivs e on a par t icu lar su bnet . •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

IGMP Version 1 By Cisco Systems, Inc.

lish2 er:d Cisco Press RFCPub 111 ef ines t he sp ecificat ion for I GMP Version 1. A diagr am of t h e pack et for m at is foun d Pub Dat e: Sep tem ber 1 1, 2 003 in Figur e 45 - 5. I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 4 5 -5 . I GM P Ve r sion 1 Pack e t For m a t

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age I n Ver sion 1 , t her e ar e ju st t w o d iff er ent t yp es of I GMP m essag es: Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Mem bership qu er y I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin rgepor p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Mem bership t t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st . Lear por at er int er net w or kin onding g t echn tolog t o a LAN/ Host s ry sen d ou nt Ihow GMPt o m incor emb er ship ep ort s cor r esp o a ies p artinicular m u ltWAN icast env g rouirponm t o ent . Com plet an in d tuerest pdat ed ed in chapt secur it y , st or age, optper icaliodically net w or ksend in g, sscalabilit indicat e et hwatit h t h new ey are joiner insg on t hat gr oup. The r out er out an I y, GMP and is book a ify com e an d u pt o-host d at eon r efter t o t he t op t hat areinessen t ial t o all m emspeed, b er shipt hquer y t o isver t hplet at at least one heence sub net is st ill ics int er est ed r eceiv ing ordir kinect g ped roftessionals, r egar pert tnet r affwic o t hat g r oup. W dless hen t hoferex e is n oise. r eply t o t hr ee con secut iv e I GMP mem ber sh ip qu er ies, t he r out er t im es out t he g r oup and st ops f orw ar din g t r af fic d ir ect ed t ow ar d t hat gr oup. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions IGMP Version 2 r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . t o en su re con cept comp Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em RFC 223 s,6pr d ef ovid ines in gt he am sporecificat e r ealist ionicfor pictI GMP ur e ofVersion t he real2. w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease A iagr t he packet at f ollow s ining Figur - 6. m ake mor e in t elligent , cost - eff icient pr dodu ctam iv it yofan d im pr ov efor effmiciency, help t heer 45 eader decisions for t h eir net w ork s.

Figu r e 4 5 -6 . I GM Pv2 M e ssa ge For m a t

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II nt rn etsion w or k2ing Te chnologie s Hr atndbook , Four th Edit ion n eVer , t her e ar e fou y pes of I GMP messag es: By Cisco Systems, Inc.

Mem bership qu er y Pub lish er: Cisco Press Pub Dat e: Sep1tem ber 1ber 1, 2sh 003 Version mem ip

r epor t

I SBN: 1- 58 705 -1 19 -2

Version 2 mem ber sh ip r epor t Pages: 11 28 Leav e gr oup I GMP Ver sion 2 w or k s basically t h e same as Ver sion 1 . The main dif fer en ce is t hat t here is a leave g rou p messag e. The h ost s now can act iv ely comm un icat e t o t h e local m ult icast rou t er t heir Theent u pdat editeion b est - selling in- one netou w tork r ef erence ides cover int ion ted o leav t heofgrt he oup. The r out erallt h en sends a ing gr oupsp ecificpqrov uery and detage erm of ines essent ial tan e aining t ech nologies. w het her h erdecu art et ingan yedg rem host s in t er est ed in r eceiv ing t h e t r aff ic. I f t h er e ar e no r ep lies, t he rou t er t imes ou t t h e gr oup and st ops for w ard ing t he t r af fic. This can gr eat ly r ed uce t he leav e lat ency comp ared t o I GMP Ver sion 1. Unw an t ed an d u nnecessar y t r aff ic can b e st opped mu ch Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom sooner. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Multicast in the Layer 2 Switching Environment The d ef ault behav ior for a Lay er 2 sw it ch is t o f or w ard all m ult icast t r af fic t o ev er y por t t hat belongs t o t h e dest inat ion LAN on t h e sw it ch. This w ould defeat t he p ur pose of t he sw it ch, w hich is t o lim it t raf fic t o t he por t s t hat need t o r eceiv e t he d at a. •

Table of Content s

•Tw o m et hod sI ndex ex ist b y w hich t o deal w it h m ult icast in a Lay er 2 sw it chin g env ir onm en t Ieff nt e rn et wly or—Cisco k ing Te chnologie s H a ndbook , Four icient Gr oup Manag em ent PrthotEdit ocolion( CGMP) and I GMP snooping . By Cisco Systems, Inc.

Cisco Management Protocol Pub lish Group er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

CGMP IisSBN: a Ciscodeveloped pr ot ocol t hat allows Cat aly st sw it ch es t o lever age I GMP infor m at ion 1- 58 705 -1 19 -2 on Cisco r out ers t o m ak e Lay er 2 for w ar ding decisions. CGMP m u st be conf igur ed bot h on t he Pages: 11 28 m ult icast r out er s and on t he Layer 2 sw it ch es. Th e net r esult is t hat w it h CGMP, I P m ult icast t r aff ic is deliver ed on ly t o t h ose Cat alyst sw it ch por t s t h at ar e int er est ed in t he t r aff ic. All ot her por t s t hat h ave not ex plicit ly requ est ed t he t r af fic w ill not r eceive it . The b asic con cept of CGMP is show n in Figur e 45 - 7. Wh en a host j oins a mu lt icast gr oup ( par t The edit ionuof t he bed estI-GMP selling all- inorkming r ef erence of1. 2 .3 , A) , itu pdat m ulted icast s an nsolicit m emb er one ship net r epwort essage t o t hep rov t argides et grcover oup age ( 2 24. essent ial an d cu t t ingedg e t ech nologies. in t his exam p le) . Th e I GMP repor t is passed t hr ou gh t he sw it ch t o t he rou t er for t he nor m al I GMP pr ocessin g. Th e r out er ( w hich mu st hav e CGMP enab led on t his int er f ace) r eceiv es t his I GMP repor t and pr ocesses it as it nor m ally wou ld, bu t in add it ion it cr eat es a CGMP join Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom m essage an d send s it t o t he sw it ch. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

e 4 5ologies -7 . Ba Opker a tand ionst or age Cov erag e of cut t ing Figu edge rt echn liksi ec optCGM ical nP et wor ing Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient The sw it ch receiv es t his CGMP j oin message and t h en add s t he p or t t o it s cont ent addr essab le decisions for t h eir net w ork s. m em or y ( CAM) t ab le for t hat m u lt icast g r oup. Su bseq uent t r aff ic direct ed t o t h is mu lt icast gr oup w ill be f or war d ed out t he por t f or t hat host . Th e r out er por t is also added t o t he ent r y f or t he m ult icast gr oup . Mult icast r out er s m ust list en t o all m ult icast t r af fic f or ever y gr oup because t he I GMP con t r ol m essages ar e also sen t as mu lt icast t raf fic. Wit h CGMP, t he sw it ch m ust list en only t o CGMP join and CGMP leave messages fr om t h e r out er. The r est of t he mu lt icast t raf fic is for w ar ded using it s CAM t able ex act ly t he w ay t he sw it ch w as desig ned.

IGMP Snooping I GMP sn ooping r eq uir es t he LAN swit ch t o ex am ine, or snoop, som e Layer 3 inf or mat ion in t he I GMP packet s sent bet w een t he h ost s and t he rou t er . W hen t he sw it ch hear s t he I GMP h ost r ep or t f rom a host for a par t icular m ult icast gr oup , t h e sw it ch adds t he h ost ' s por t num b er t o t he •associat ed mu Table of Content lt icast t able sent r y . When t he sw it ch h ear s t he I GMP leav e gr oup m essage fr om a •host , it r em ov I ndex es t he h ost ' s por t fr om t h e t able ent ry . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Becau I GMP cont By Ciscose Systems, Inc. r ol m essag es are t ran sm it t ed as m ult icast pack et s, t hey ar e indist ingu ish able fr om mu lt icast d at a at Lay er 2. A sw it ch r unn ing I GMP snoop ing ex am ine ev er y m ult icast dat a pack et t o ch eck w het h er it cont ains an y per t inent I GMP m ust con t r ol inf orm at ion. I f I GMP Pub lish er: Cisco Press snoopin g h as been im plem en t ed on a low - end sw it ch w it h a slow CPU, t h is could hav e a sever e Pubm Dat e: Sep tem ber 1w 1,hen 2 003dat a is t r ansm it t ed at high r at es. The solut ion is t o im plem en t I GMP per for ance im pact I SBN: 158 705 -1 19 -2 snoopin g on hig h- end swit ches w it h special ASI Cs t hat can p er for m t he I GMP check s in 11 28 is ideal f or low - end sw it ches w it hou t special har dw ar e. har dwPages: ar e. CGMP

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Multicast Distribution Trees Mu lt icast - capable r out er s cr eat e dist rib ut ion t rees t hat cont r ol t h e pat h t h at I P m u lt icast t raf fic t ak es t hr oug h t h e net w or k t o d eliv er t r aff ic t o all r eceiv er s. The t w o basic t y pes of m ult icast dist r ibut ion t r ees ar e sour ce t r ees an d sh ared t r ees. •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Source Trees

By Cisco Systems, Inc.

The sim plest for m of a m ult icast dist r ibut ion t r ee is a sour ce t r ee w h ose root is t he sou rce of t h e Pub lish er: Cisco Press m ult icast t r ee and w hose br anches f orm a span ning t r ee t hr ough t h e net w or k t o t h e r eceiver s. Pub Dat e: Sep tem 1 1, t2he 003shor t est p at h t hr ough t h e net w ork , it is also r ef err ed t o as a shor t est Becau se t his t r ee ber uses I SBN: 158 705 -1 19 -2 pat h t r ee ( SPT) . Pages: 11 28

Figur e 45 - 8 sh ows an ex am ple of an SPT f or gr oup 22 4. 1. 1. 1 r oot ed at t he sour ce, Host A, an d connect ing t w o r eceiv er s, host s B and C.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Figu r e 4 5 -8 . H ost A Sh or t e st Pat h Tr ee essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient The sp ecial S, G) decisions fornot t h at eirion netofw (ork s. , pr onoun ced " S com m a G, " enum erat es an SPT in w hich S is t h e I P add ress of t he sou rce an d G is t h e m ult icast gr oup add ress. Using t his n ot at ion, t he SPT f or t h e exam ple in Figur e 45 - 7 w ou ld b e ( 19 2. 1. 1. 1, 2 24. 1 .1 .1 ) . The ( S,G) not at ion im plies t hat a separ at e SPT ex ist s for each indiv idual sou rce sending t o each gr oup , w hich is cor r ect . For ex am ple, if Host B is also sendin g t raf fic t o gr oup 22 4. 1. 1. 1 and

host s A and C are receiv ers, t hen a sep arat e ( S,G) SPT w ould ex ist w it h a not at ion of ( 19 2. 2. 2. 2, 2 24. 1. 1. 1 ) .

Shared Trees Unlike sour ce t r ees t hat hav e t heir r oot at t he sou rce, shar ed t r ees u se a single com m on r oot •placed at some Table Content s in t he n et w or k . This shar ed root is called t he r en dezvou s point ( RP) . chof osen point •

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IFigur nt e rne et 45 w or- k9ing chnologie H a ndbook , Four sh Te ows a sharsed t r ee f or t hethg Edit rou ion p 224 .2 .2 . 2 w it h t he root locat ed at Rout er D . When using a sh ared t r ee, sour ces mu st send t heir t r aff ic t o t h e r oot , and t h en t h e t r aff ic is for w ar ded By Cisco Systems, Inc. dow n t he sh ared t r ee t o r each all r eceiv er s. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Figu r e 4 5 -9 . Sha r ed Di st r ibu t i on Tr e e

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. I n t his exam p le, m ult icast t r af fic f rom t he sour ce host s A and D t rav els t o t he r oot ( Rout er D) and t h en n tain he sh t r ee o t hstean t wding o r eceiv er s,and hostWAN s B and C.orBecause sour ces Reader s wdow ill obt a gared reat er untder of LAN n et w k ing, p arall t icu lar ly t hin e the m ult icast gr oup use a comm on shar ed t r ee, a w ildcar d n ot at ion wr it t en as ( * , G) , p ron ounced har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on "astbar com ma eG,of" repr esent t his case, * ming eans allailed sourdescr ces, ipt andion t he G r iew ep resent the r oad r ang int egr al sys stt he emtsree. andI nserv ices, in clud det s, rev questsions m ult icast gr oup . Ther ef or e, t he shar ed t ree show n in Figur e 45 8 w ou ld b e w rit t en as ( * , t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . 22 2. 2.e2)is . also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Cov4.erag syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Bot h SPT an d shar ed t r ees ar e loop- f r ee. Messages are replicat ed on ly w here t he t r ee br anches. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odubers ct iv itofy mu an dlt im pr ov eff iciency, me, ake icient Mem icast greoups can joinhelp or ing leavt eheatr eader an y t im somor t heedin istt relligent ibu t ion, tcost r ees- eff m ust be decisions for t h eir net w ork s. dy nam ically updat ed . When all t he act iv e r eceiver s on a p art icular br anch st op r equest ing t he t r aff ic for a par t icular m ult icast g rou p, t h e r out ers pr une t hat br anch f r om t he dist rib ut ion t ree and st op for w ar ding t r aff ic dow n t hat br anch. I f on e r eceiv er on t hat br anch becomes act iv e and r eq uest s t he m u lt icast t r af fic, t he rou t er dy nam ically m odif ies t he dist r ibut ion t r ee and st art s for w ar ding t r af fic again .

Shor t est pat h t rees hav e t he adv ant age of cr eat ing t he op t imal pat h bet w een t h e sou r ce an d t he r eceiver s. This gu ar ant ees t he m inim um am oun t of n et w or k lat ency f or for w ar ding m ult icast t r aff ic. This opt im izat ion does come w it h a pr ice, t h ough : Th e r out ers mu st m aint ain pat h inf orm at ion for each sour ce. I n a n et wor k t h at h as t hou san ds of sour ces and t housand s of gr oup s, t his can quick ly becom e a r esour ce issue on t he r out er s. Memor y consum pt ion f rom t he size of t he m ult icast r out in g t able is a f act or t hat net w or k desig ner s m ust t ak e int o considerat ion . •

Table of Content s

Shar ed t rees hav e t h e adv ant age of requ iring t h e m in imu m am ount of st at e in each r out er . This • I ndex low er s t h e ov er all m em ory r equ ir em en t s for a net w or k t hat allow s only shar ed t rees. The I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion disadv ant ag e of sh ar ed t r ees is t hat , u nder cert ain circu mst ances, t he p at hs b et ween t he sour ce By Cisco Systems, and r eceiver s mInc. ight not be t he opt im al p at hs—w hich mig ht in t rod uce som e lat en cy in pack et deliver y. Net w or k d esigner s m ust car efu lly consider t h e placem ent of t he RP w hen imp lem ent ing an en ent Press w it h on ly sh ar ed t r ees. Pubvir lishonm er: Cisco Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Multicast Forwarding I n unicast r out ing , t r aff ic is r out ed t hr ough t h e net w or k along a single p at h fr om t h e sour ce t o t he dest in at ion h ost . A u nicast r out er does not r eally car e abou t t h e sou r ce ad dr ess—it only cares ab out t he d est inat ion add ress and how t o f or war d t he t r affic t ow ard s t hat dest inat ion. Th e •r out er scans Table s ing t able an d t hen for w ard s a sing le cop y of t he u nicast pack et out t h rouofghContent it s r out •t he cor r ect int I ndex er face in t he dir ect ion of t h e dest in at ion. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

IByn Cisco mu lt Systems, icast rouInc. t ing, t he sour ce is sen ding t r aff ic t o an ar bit r ar y gr oup of host s r epr esent ed by a m ult icast gr oup add r ess. The m u lt icast r out er mu st det er mine w hich d ir ect ion is u pst r eam ( t ow ar d t he sour ce) and w hich dir ect ion ( or dir ect ion s) is dow n st r eam . I f t here are mu lt ip le Pub lish er: Cisco Press dow n st r eam pat hs, t he r ou t er replicat es t he p ack et an d f or w ard s t he t raf fic d ow n t h e tem ber 1 1, 2 003 appPub ropDat riate:eSep dow nst r eam pat hs—w hich is not necessarily all p at hs. This con cept of for w ar ding I SBN: 158 19 -2 m ult icast t r aff ic705 aw-1ay fr om t he sour ce, r at h er t han t o t he r eceiver , is called r ev er se p at h for w arPages: ding. 11 28

Reverse Path Forwarding The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Rev er se pat h f orw ar ding ( RPF) is a fu ndam ent al con cept in mu lt icast rou t ing t hat enables essent ial an d cu t t ing- edg e t ech nologies. r out er s t o cor r ect ly f orw ar d m ult icast t r aff ic dow n t he d ist r ibu t ion t r ee. RPF m ak es use of t he exist ing un icast rou t ing t able t o det erm ine t he up st r eam an d d ow nst ream n eig hbor s. A r out er for w arCon ds cise a m ult pack onlyolog if it ies is ressen eceiv ed e wor upstkring eamprint er face.als This RPF eckf rom helps ov icast er v iew s ofett echn t ialon t o tnhet ofession at all levchels, t o guar ant ee t h at t h e dist r ibut ion t r ee w ill be loopf ree. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

RPF Check Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age When a m u lt icast p ack et ar r ives at a r out er , t h e r out er per for m s an RPF check on t he p ack et . I f Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . t he RPF check is su ccessf ul, t h e pack et is for w ar ded. Ot herw ise, it is d rop ped. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat For t r aff ic flow ing dow n a sour ce t r ee, t he RPF ch eck p rocedur e w or k s as f ollow s: enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing St e p 1 . Rou t er look s u p t he sour ce addr ess in t he un icast rou t ing t able t o det erm ine indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . w het her it has ar r ived on t he int er face t h at is on t h e rev er se pat h b ack t o t h e sou r ce. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all St e p 2 . I f packet has ar r ived on t he int er face leading back t o t he sour ce, t he RPF check is net w or kin g p rof essionals, r egar dless of ex pert ise. successful and t he p ack et is f or w ard ed . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e St e p 3 . I f t he RPF ch eck in St ep 2 f ails, t he pack et is dr op ped. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Figur e 45 - 10 sh ows an ex am ple of an unsuccessfu l RPF check . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Figu r e 4 5 -1 0 . RPF Che ck Fai ls decisions for t h eir net w ork s.

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Dat e: Sep tem ber 1 1, 2 003 A mPub u lt icast p ack et f r om sour ce 151 .1 0. 3. 21 is r eceived on int erf ace S0. A check of t h e un icast I SBN: 58 705 19 -2 t he in t erf ace t hat t his r out er w ould use t o for w ar d unicast dat a t o r out e t ab le 1show s -1 t hat Pages: 28S1 . Becau se t he p ack et h as arr iv ed on S0, t he p ack et w ill be discar ded. 15 1. 10. 3 .2 111is

Figur e 45 - 11 sh ows an ex am ple of a successfu l RPF ch eck .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of e 4 5 -1 1 . RPF Che ck Succee ds essent ial an d cu t t ing- edg Figu e t echrnologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, book is pack a com anr d u p-on t o- S1. d at eThr ef ence t o t hes ttop t hat are essen ial t oand all This t im e t hteh is m ult icast etplet hase ar ived e er rou t er check h eics unicast r out in g t table netds w or pert ch ise. fin t hkin at gS1p rof is tessionals, he cor r ectr egar int er dless face. of TheexRPF eck p asses and t he packet is for w ar ded. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Protocol-Independent Multicast Pr ot ocol- independ en t m ult icast ( PI M ) g et s it s nam e f rom t he f act t h at it is I P r out ing pr ot ocolindepend en t . PI M can lever age w hichev er unicast r out in g p rot ocols ar e u sed t o p opulat e t he un icast rou t ing t able, including EI GRP, OSPF, BGP, or st at ic r out es. PI M u ses t h is unicast r out in g •inf orm at ion tTable ofor Content o perf m t hes m u lt icast f or w ard in g fun ct ion , so it is I P pr ot ocol- independ en t . •Alt hou gh PI MI ndex is called a mu lt icast r ou t ing pr ot ocol, it act ually uses t he unicast r out in g t ab le t o Iper nt efor rn et Teerse chnologie H a ndbook , Four th Edit ion mw or t hkeing r ev p at hs for w ard ing ( RPF) check fu nct ion in st ead of bu ild in g up a com plet ely independ en t m uInc. lt icast r out in g t able. PI M d oes n ot send and r eceive m u lt icast r ou t in g upd at es By Cisco Systems, bet w een r out er s like ot her r out ing pr ot ocols do. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

PIM Dense I SBN: 1- 58 Mode 705 -1 19 -2 Pages: 11 28

PI M Dense Mode ( PI M - DM) u ses a pu sh m odel t o flood m ult icast t r aff ic t o ev er y cor ner of t he net w or k. This is a br ut e- for ce m et hod for d eliv er ing d at a t o t he r eceiv er s, bu t in cer t ain app licat ions, t h is m ig ht be an eff icient mechanism if t h er e ar e act ive receiv ers on ev er y sub net in t he net w ork . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of PI M- DM init ially floods mu lt icast t raf fic t hr ough out t he net w or k . Rout er s t h at d o not hav e any essent ial an d cu t t ing- edg e t ech nologies. dow n st r eam neigh bor s pr un e back t he unw ant ed t r aff ic. This pr ocess r epeat s ev er y 3 m inut es. The f lood and pr une mechanism is h ow t he rou t er s accum ulat e t heir st at e infor m at ion—b y Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom r eceivin g t h e dat a st ream . Th ese dat a st r eam s cont ain t h e sou rce an d g r oup infor m at ion so t hat nov ice t o ex pert . dow n st r eam r out er s can b uild up t heir m ult icast for w ar ding t ables. PI M- DM can sup por t on ly sour ce t r ees—( ent ries.cov I t erag canneotofbeimused t o build sharVoI ed P dist rib EAP ut ion t ree. New chaptS, erG) s include por t ant t opicsa like and Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

PIM Sparse Mode

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

PI Spar ( PI Mnologies - SM) u ses a pu ll mod el ttoh dEd eliv er ,mu t r affic. Onlyrefer net wence or kst hat t hat I nM t ern et wseorMode k in g Tech Hand book , Four it ion is ltaicast com pr ehensive hav e act iv e receiv ers t hat hav e exp licit ly r eq uest ed t he dat a will b e for w ar ded t he t r af fic. PIing Menables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork SM is defined in RFC 23 62. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . PI M- plet SM euses shar an ed dt ruee t o ed distchapt rib ut er e tsh on e infor m it atyion about on y,t he Com w it ha new pdat secur , st or age, act optive icalsou netrces. w or kDepending in g, scalabilit conf ig ur at ion opt ions, t h e t r aff ic can r emain on t he shar ed t r ee or sw it ch over t o an opt im ized and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all sour ce dist rib ut ion t r ee. Th e lat t er is t he d ef ault behav ior for PI MSM on Cisco r out er s. The net w or kin g p rof essionals, r egar dless of ex pert ise. t r aff ic st art s t o f low dow n t h e sh ared t r ee, an d t hen rou t er s alon g t h e pat h det er m in e w het her t her e iss awbet t er ain patah gt oreat t heersour ce.stI an f a ding bet t er m oreand direct p at hw exorist s, t he d esign Reader ill obt un der of , LAN WAN n et k ing, p ar t icu laratlyedt hr eout er ( t h edw rou er pr closest t o and t he rser eceiv er ) inv w illolvsend a join message t ow ar d t he ceion andis tpr hen r er outon e har ar te, ot ocols, v ices ed . Fu ndam ent al t ech nology infsour or mat ov ided t he raf fic alon patalh .sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions a b r toad r ang e goft his int egr t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . PI M-erag SM ehas t h e concep of nan it uses sh ared r ees—at in it ially . The RP m ust be Cov is also ext endted ot RP, onlysince t o new n et wor k ing tconcep t s, least but also t o old er , legacy adm inist r at ively conf ig ur ed in t he net w ork . Sou rces r eg ist er w it h t he RP, and t h en dats ainisw hich syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent for w ar ded dow n t he shar ed t ree t o t he r eceiv ers. I f t he sh ared t r ee is not an op t imal pat h pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease bet w een t h e sou r ce an d t he r eceiv er , t h e r out ers dy nam ically cr eat e a sour ce t r ee and st op pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient tdecisions r aff ic fr om f low in g dow n t he shar ed t ree. This is t h e defau lt b eh avior in I OS. Net w or k for t h eir net w ork s. adm inist r at or s can f or ce t raf fic t o st ay on t he shar ed t ree b y using a conf igur at ion opt ion ( lp pim spt - t h reshold infin it y) . PI M- SM scales w ell t o a net w ork of any size, in clu ding t hose w it h WAN link s. The ex plicit join m ech anism pr ev ent s u nw ant ed t r aff ic fr om f looding t he W AN link s.

Sparse-Dense Mode Cisco has im p lem ent ed an alt er nat iv e t o choosing j ust d en se m od e or ju st spar se m ode on a r out er int er face n ew I P. This w as necessit at ed b y a chan ge in t he p ar adigm f or f orw ar ding m ult icast t r aff ic v ia PI M t h at b ecam e app arent du rin g it s developm ent . I t t ur ned out t hat it w as m or e ef ficien t t o choose spar se or dense on a p er gr oup basis r at her t han a per r out er int er face •basis. Spar seTable d enof seContent mod e sfacilit at es t his ab ilit y . •

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adm istchnologie r at or s can also config spar INet nt e w rnork et w or k inginTe s H a ndbook , Fourur th eEdit ionse- dense m ode. Th is con figu rat ion op t ion allow s indiv idual gr oup s t o b e r un in eit her spar se or dense m ode, d ep en ding on w het her RP By Cisco Systems, Inc. inf orm at ion is av ailab le for t hat g r oup. I f t h e r out er lear ns RP in for m at ion f or a par t icu lar gr oup, it w ill b e t r eat ed as spar se m ode; ot h er w ise, t hat gr oup w ill be t r eat ed as d en se mod e. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Multiprotocol Border Gateway Protocol Mu lt ip rot ocol Bord er Gat eway Prot ocol ( MBGP) gives a m et h od f or p rov ider s t o d ist in guish wh ich r out e p ref ix es t hey w ill use f or per for m ing m ult icast RPF checks. Th e RPF check is t he fu ndam ent al mechan ism t h at r out er s u se t o det er min e t he p at hs t h at m ult icast f or war din g t rees •w ill follow anTable of Content d su ccessf ullys deliv er m ult icast cont ent fr om sour ces t o r eceiv er s. •

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IMBGP nt e rn etis w or k ing ibed Te chnologie a ndbook , Four Edit ion descr in RFCs H22 83, Mult ipr th ot ocol Ext ensions f or BGP- 4 . Since MBGP is an ex t ension of BGP, it br ings alon g all t he ad min ist r at iv e m ach inery t hat pr ovider s and cust om ers lik e in By Cisco Systems, Inc. t heir int er dom ain rou t ing env ir onm ent . I n clu ding all t he in t er- AS t ools t o filt er and cont r ol r out ing ( e. g. , r out e m ap s) . Theref ore, b y using MBGP, an y net w or k ut ilizing int er nal or ex t ern al Pub lish er: Cisco Press BGP can ap ply t he m u lt ip le policy con t rol kn obs f am iliar in BGP t o specify r out in g ( an d t hereby Dat e: Sep tem ber 1 1, 2 003 for wPub ar ding ) p olicy f or m ult icast . I SBN: 1- 58 705 -1 19 -2

Tw o p Pages: at h at11 t r 28 ib ut es, MP_REACH_NLRI an d MP_UNREACH_ NLRI h ave b een int r odu ced in BGP4+ . These new at t r ibu t es cr eat e a sim ple w ay t o carr y t w o set s of rou t ing infor m at ion—on e for un icast rou t ing and one f or m ult icast r out ing . The r out es associat ed w it h m ult icast rou t ing ar e used t o bu ild t h e m ult icast dist r ib ut ion t r ees. The m ain adv ant ag e of MBGP is t hat an in t ern et can sup por t n oncongr u en t un icast and m ult icast The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t opolog ies. Wh en t he unicast and m ult icast t op ologies are con gr uent , MBGP can su ppor t diff erent essent ial an d cu t t ing- edg e t ech nologies. policies f or each. MBGP pr ov ides a scalable policy based int er dom ain r out ing pr ot ocol. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Multicast Source Discovery Protocol I n t he PI M Spar se mod e m odel, m ult icast sou rces and r eceiv er s m ust regist er w it h t heir local Rend ezv ous Poin t ( RP) . Act ually, t he closest rou t er t o t h e sour ces or receiv ers regist ers w it h t h e RP but t he point is t hat t he RP k now s ab out all t he sour ces and receiv er s for an y par t icular •gr oup . RPs inTable of Content ot h er d om ains s hav e no w ay of k now ing about sour ces locat ed in ot h er dom ains. •MSDP is an elegan I ndex t w ay t o solv e t h is pr oblem. MSDP is a m ech anism t hat connect s PI M- SM Idom nt e rn et w or k ing Te chnologie ndbook Four ains an d allow s RPs st oH ashar e in, for mthatEdit ionion ab out act iv e sour ces. Wh en RPs in r em ot e dom ains k now out act iv e sour ces t hey can p ass on t h at in for m at ion t o t heir local r eceiver s and By Ciscoab Systems, Inc. m ult icast dat a can b e for w ar ded bet w een t he d omain s. A nice f eat u re of MSDP is t hat it allow s each d omain t o main t ain an ind ep en dent RP w hich does not r ely on ot h er dom ain s, but it d oes Pub lish er: Cisco Press enable RPs t o f or w ard t r aff ic bet w een dom ains. Pub Dat e: Sep tem ber 1 1, 2 003

1- 58 705 -1 19 -2 est ab lishes an MSDP peerin g session using a TCP connect ion wit h t h e RPs The RPI SBN: in each dom ain Pages: 11ains 28 in ot her dom or w it h b ord er rou t ers leadin g t o t he ot her dom ains. Wh en t h e RP lear ns ab out a n ew m ult icast sour ce w it h in it s ow n dom ain ( t hr oug h t he n orm al PI M r eg ist er m ech anism) , t he RP en cap sulat es t he f irst dat a packet in a Sour ce Act iv e ( SA) message and sends t he SA t o all MSDP peers. Th e SA is f orw ar ded by each receiv ing peer using a m odif ied RPF ch eck , un t il it r eaches ev er y MSD P r out er in t he in t erconn ect ed net w ork s—t heor et ically t he en t ire m u lt icast int . I ed f t he r eceiv ingt he MSDP is an and net t h ew RP as raef(erence * , G) ent ry fides or t hcover e gr oup Theerunet pdat edit ion of b est -peer selling all-RP, in- one ork hing p rov ageinoft he SA ( t here is an in t er est ed r eceiver ) , t h e RP will cr eat e ( S, G) st at e for t he sour ce and join t o t he essent ial an d cu t t ing- edg e t ech nologies. shor t est pat h t r ee for t he st at e of t h e sour ce. Th e encapsulat ed d at a is d ecapsulat ed and for w ar ded dow n t hat RP' s sh ar ed t r ee. When t he pack et is r eceived by a r eceiver 's last hop r out erCon , t he cise last ov- herop v iew m ay s ofalso t echn j oin olog t heiesshor essen t estt ial patt o h nt ret eewor t o kting he sour pr ofession ce. Theals sour at ce' all slev RPels, f rom per iodically nov ice sends t o ex pert SAs, . w h ich include all sou r ces w it hin t hat RP' s ow n dom ain. Figur e 45 - 12 show s how dat a w ould flow b et w een a sour ce in d omain A t o a r eceiv er in d om ain E. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Figu r e 4 5 -1 2 . M SD P Exa m pl e

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. cise er v iewfor s ofpeer t echn essen t ial t o Ser n etvwor ing ofession als alldlev MDSPCon w as devov eloped ingolog beties w een I nt er net ice kPr ov pr iders ( I SPs) . Iat SPs id nels, ot wf rom ant t o nov ice t o ex pert . r ely on an RP m ain t ained by a com pet ing I SP t o ser v ice t heir cu st omer s. MSDP allow s each I SP t o hav e t heir ow n local RP an d st ill f orw ar d and r eceive mu lt icast t raf fic t o t he I n t er n et . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Anycast RP—Logical RP

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . A v er y usef ul applicat ion of MSD P is called any cast RP. This is a t echn ique f or conf ig ur ing a I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat m ult icast spar se- m ode net w ork t o pr ov ide f or fau lt t oleran ce and load shar ing w it hin a sing le enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing m ult icast dom ain. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu . Lear n how incor w ore kin t echn in t o a LAN/ WAN env ir,onm Tw o st orrymor e RPs ar et ocon figupor redatweitint h ter henet sam I P gadd r essolog on ies loopback int er faces—say 1 0. ent 0. 0.. 1, Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit for ex am ple ( r efer t o Figur e 45 - 13) . Th e loopback ad dr ess shou ld b e con figu red as a 32 bit y, and speed, is book is raeam comrou plett er e sanard eu conf p- t o-igur d ated e r ef encet hey t o t he t optics essen t ial t o all add ress. Allt thhe dow nst soert hat k now hatt hat t heirare local RP's net w or kin g p rof essionals, r egar dless of ex pert ise. add ress is 10 .0 . 0. 1. I P rou t ing aut om at ically select s t he t opolog ically closest RP f or each sour ce and r eceiver . Because som e sour ces m ig ht en d up using one RP and som e receiv ers a dif fer en t Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e RP, t here need s t o b e some way for t h e RPs t o exchan ge inf or mat ion abou t act iv e sour ces. This har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on is don e w it h MSDP. All t h e RPs ar e conf igur ed t o be MSDP p eer s of each ot h er . Each RP w ill k now a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions abou t t h e act ive sour ces in t he ot her RP's ar ea. I f any of t h e RPs f ail, I P r out ing w ill conv er g e t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . and one of t he RPs w ill becom e t h e act iv e RP in bot h ar eas. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Figu r e 4 5 -1 3 . An ycast RP decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

NO TE The An ycast RP ex amp le abov e uses I P add resses f r om RFC 191 8. Th ese I P ad dr esses The uar pdat edmedit of t he at b est selling all-bor in- one rov ides cover age e nor allyion blocked int-er dom ain der s net andw ork t hering ef orr ef e erence ar e notpaccessible t o ot herof essent ial an d cu t t ingedg e t ech nologies. I SPs. You mu st use v alid I P addr esses if you w ant t he RPs t o be r each able fr om ot her dom ains. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

NO Cov TE erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age The e used lystt ems, o set w u portldw he init connin ectnet ionwbet w eenf orsour ers. Aut hRPs oredarby CiscoonSy ide ial leader or king t heces I n tan er nd etreceiv . Aft er t he last - hop r out er s join t he sh ort est p at h t r ee, t h e RP is no lon ger necessary . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . LearAddress n how t o incor por at e int Client er net w orAllocation kin g t echn ologProtocol ies in t o a LAN/ WAN env ir onm ent . Multicast Dynamic Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all The icast ess Dyn am ic Client ionise. Pr ot ocol ( MADCAP) is defined in RFC 27 30 as a net wMu orltkin g p Addr rof essionals, r egar dless Allocat of ex pert pr ot ocol t h at allow s host s t o r eq uest a mu lt icast addr ess allocat ion dy nam ically f rom a MAD CAP ser v er. sThe er y er sim o an t he w ayofDHCP w or WAN ks t oday b uilt client serv er Reader w illconcep obt aint aisgvreat unilar dertst ding LAN and n et wan ordk is ing, p aron t icualar ly t h/ e m odel. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext endZone ed n ot Announcement only t o new n et wor k ing concep t s, but also t o old er , legacy Multicast-Scope Protocol syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Mu lt icast - Scope Z on e Ann ouncem ent Pr ot ocol ( MZ AP) is defined in RFC 27 76 as a p r ot ocol t hat pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient allow s net w or ks t o aut om at ically discov er adm inist r at ively scop ed zon es r elat ive t o a par t icu lar decisions for t h eir net w ork s. locat ion.

Reliable Multicast—Pragmatic General Multicast

Pr agm at ic Gen er al Mu lt icast ( PGM) is a r eliable m u lt icast t ran sp ort pr ot ocol f or app licat ions t hat r eq uir e or dered, dup licat e- fr ee, m ult icast dat a deliv ery fr om m ult iple sour ces t o m ult ip le r eceiver s. PGM guar ant ees t h at a receiv er in a m ult icast gr oup eit her r eceives all d at a p ack et s fr om t ran sm ission s and r et ran sm ission s, or can d et ect u nr ecov erab le dat a packet loss. The PGM Reliable Tr anspor t Pr ot ocol it self is im plem ent ed on t he sour ces and t he r eceiv er s. The sour ce main t ains a t ran smit w in dow of ou t going dat a pack et s and r et r an sm it s ind ividu al pack et s w hen it r eceives a negat iv e ackn ow ledg m en t ( NAK) . Th e net w or k elem en t s ( r out er s) assist in • Table of Content s supp ressin g an im plosion of NAKs ( wh en a failur e does occur ) an d aid s in ef ficien t f orw ar din g of • I ndex t he ret r ansm it t ed d at a j ust t o t he net w ork s t h at n eed it . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

PGM By Cisco is Systems, int end edInc. as a solu t ion f or m ult icast app licat ions wit h b asic r eliab ilit y requ ir em en t s. The specif icat ion f or PGM is net w or k layer - independ en t . The Cisco im plem en t at ion of PGM Rout er Assist su er: ppor t s PGM Pub lish Cisco Press ov er I P. Pub Dat e: Sep tem ber 1 1, 2 003

Today , t h e specif icat ion for PGM is an I n t er net dr aft t hat can b e fou nd on t he I ETF w eb sit e -1 19 -2 ( ht t p: /I/SBN: w w w1-.58 iet705 f .or g ) und er t he nam e " PGM Reliable Tr anspor t Pr ot ocol. " Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What is t h e ran ge of av ailable I P m ult icast add resses?

2:

I ndex is t h e pur pose of I GMP? What

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

: What By Cisco 3 Systems, Inc.is 4:

an adv ant ag e of I GMPv 2 ov er I GMPv 1?

What is a pot ent ial d isadv ant age of I GMP sn ooping ov er CGMP on a low - end Lay er 2 swit ch?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 58 705 is -1 19 5 : 1-What an-2 adv ant ag e

of sh or t est pat h ( or sour ce) t r ees com par ed t o shar ed t rees?

Pages: 11 28

6:

What is an adv ant ag e of using sh ar ed t r ees?

7:

What inf orm at ion does t h e r out er use t o do an RPF ch eck ?

8 : edWhy is prof ottocolultone icastnet called independ en t "p?rov ides cover age of The u pdat edit ion he b in estdependent - selling all-minw ork "ing r ef erence essent ial an d cu t t ing- edg e t ech nologies. 9 : What is t h e main adv ant age of MBGP? Con 1 0 :ciseHow ov erdvoiew RPs s of lear t echn n about olog sour ies essen ces f rt om ial t o ot nher et wor RPsk ing w it hprMSD ofession P? als at all lev els, f rom nov ice t o ex pert . 1 1 : What is t h e pur pose of t h e any cast RP? New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • William son, Beau. Develop in g I P Mu lt icast Net w or k s . I nd ianapolis: Cisco Pr ess, 2 000 . •

Table of Content s

•• Mult icast Quick I ndex St ar t Conf igur at ion Guide (ht t p: / / w w w . cisco.com / w ar p/ cust om er / 1 05/ 4 8. ht m l) I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 46. NetWare Link-Services Protocol • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Descr ibe t he Net w ork Link - Ser v ice Prot ocol.

By Cisco Systems, Inc.

Descr ibe r ou t in g wit h NLSP. Pub lish er: Cisco Press

Descr t heber dat a 2pack Pub Dat e: ibe Sep tem 1 1, 003 et

used b y NLSP.

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background The Net War e Link - Ser v ices Pr ot ocol ( NLSP) is a link - st at e r out ing pr ot ocol f r om Novell d esigned t o over com e som e of t he lim it at ions associat ed w it h t he I PX Rout ing I nf or mat ion Pr ot ocol ( RI P) and it s com panion pr ot ocol, t h e Ser v ice Ad ver t isem ent Prot ocol ( SAP) . NLSP is based on t he OSI •I nt er mediat eTable Content s erm ediat e Sy st em ( I S- I S) pr ot ocol an d w as d esign ed t o replace RI P Systof em - t o- I nt •and SAP, NovI ndex ell' s or iginal r out in g pr ot ocols t hat wer e designed w hen in t er net w or k s w er e local Iand nt e rn et w or ing sm Te chnologie s H a ndbook , Four th Edit r elat ivkely all. As such, RI P an d SAP arion e not well suit ed for t oday 's lar ge, g lob al intCisco er netSystems, w ork s. This By Inc. ch apt er sum m arizes t h e rou t ing pr ocesses and pr ot ocol com ponent s of NLSP. Com par ed t o RI P and SAP, NLSP pr ov id es im p rov ed r ou t ing, b et t er ef ficien cy , an d scalabilit y. I n Pub lish er: Cisco Press add it ion , NLSP- b ased r out er s are backw ar d comp at ible w it h RI P- based r out er s. NLSP- based e: Sep tem ber 1 1, 2 003 r outPub er sDat use a reliable deliver y pr ot ocol, so deliv er y is gu ar ant eed . Fur t her mor e, NLSP facilit at es I SBN: 1- 58ing 705 -1 19 -2 im pr oved r out decisions becau se NLSP- based r ou t er s st or e a com plet e m ap of t he n et w or k , not ju Pages: st nex11 t - 28 hop inf orm at ion such as RI P- based r out er s u se. Rout ing inf orm at ion is t r ansm it t ed only w h en t he t opology h as chang ed , not ev er y 60 second s as RI P- based rou t ers d o, r egar dless of w het her t h e t opology has chang ed . Add it ion ally , NLSP- based r out er s sen d ser vice- infor m at ion up dat es only w hen ser v ices chan ge, not ev er y 60 second s as SAP d oes. NLSP is ef ficien t in al b west ays. I t is par ly net usef er raefW AN link because it s sup The u pdat ed edit ionsev of er t he - selling all-t icular in- one wul orkov ing erence p rov ides cover agepor of t of Iessent PX h ead er com pr ession m akes it possib le t o r educe t h e size of p ack et s. NLSP also su ppor t s ial an d cu t t ing- edg e t ech nologies. m ult icast add ressin g so t hat rou t ing infor m at ion is sen t only t o ot h er NLSP r out er s, not t o all dev ices, as RI P does. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom I n addit sup.por t s load balancing across p arallel pat h s and im pr ov es link in t egr it y. I t novion, ice NLSP t o ex pert per iodically checks lin ks for conn ect iv it y and for t he d at a int egr it y of r out in g in for m at ion. I f a link f ails, ch es t o cov an alt erne at link eslike t h e VoI netP w and or k tEAP opology d at abases st ored New NLSP chaptsw er sit include erag ofe im porand t antu pdat t opics in each node w hen conn ect iv it y chang es occur an yw h er e in t he r ou t in g area. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age I n t er m s of scalab ilit y , NLSP can su ppor t up t o 1 27 hops ( RI P sup por t s only 1 5 h ops) an d per m it Aut s hierar h oredchical by Cisco addSy ressin st ems, g of wnor et ldw woride k n odes, leaderwinhich netallow w or king s net f or w or t he ks Itnot er cont n etain . t hou sands of LANs an d ser ver s. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

NLSP Hierarchical Routing NLSP su ppor t s h ier ar chical r out ing w it h area, d omain , and global int ern et wor k com pon en t s. An ar ea is a collect ion of con nect ed net w or ks t hat all hav e t he sam e ar ea add ress. A dom ain is a collect ion of areas t h at b elong t o t he sam e or ganizat ion . A global in t er n et w or k is a collect ion of •dom ains t hatTable of Content s t o d if fer ent or g anizat ions, bu t w it h an arm s- lengt h r elat ion sh ip. usually belong •Ar eas can beI ndex lin ked t o cr eat e r out ing dom ains, an d d omain s can b e link ed t o cr eat e a global Iint nt er e rnnet et ww orork k ing . Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

NLSP su ppor t s t hr ee lev els of h ier ar ch ical rou t ing: Lev el 1, Lev el 2, and Level 3 r out in g. A Level 1 r out er connect s net w or k seg ment s w it hin a giv en r out in g area. A Level 2 r out er conn ect s ar eas Pub lish er: Cisco Press and also act s as a Lev el 1 r out er wit h in it s ow n ar ea. A Lev el 3 r out er connect s dom ains and also Sep tem ber 1 1, 2 003 act sPub asDat a e: Level 2 r out er w it h in it s ow n dom ain. Figur e 46 - 1 illust r at es t he t hr ee rou t ing lev els I SBN: 1- 58 705 -1 19 -2 NLSP defines. Pages: 11 28

Figu r e 4 6 -1 . N LSP De fi ne s Thr e e Rou t i ng Le ve ls The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Hierarchical Routing and speed, t h is book is a comEfficiencies plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Hier ar ch ical r out ing sim plifies t he pr ocess of enlar ging a n et w or k b y r ed ucin g t he am oun t of Reader s ion w ill tobt a yg reat der st LAN and et w or ksing, lar ain. ly t hA e Level 1 inf orm at hatain ever r outer er un m ust stan or eding an dofp rocess t o WAN r out enpacket w it hpinarat icu dom har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov r out er is r equir ed t o k eep det ailed inf orm at ion only ab out it s ow n ar ea inst ead of st orin gided link -on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest st at e inf or mat ion f or ev er y r out er and net w or k seg ment in it s dom ain. To exchan ge t r aff ic w itions h tot o her en su conacept comp r eher enm sion et en ttion, and ad dit ional oreen fu rtareas, her st udy arre eas, Lev el 1 r out ust and f ind r only h e nearest Level 2 rr esou out err.ces Betf w Lev.el 2 Cov e isert also ed addr n ot only t o new et wor k ing concep old er r outerag er s adv ise ext t h eend area ess( es) on lynfor t h eir r espect iv et s,arbut eas,also not t toheir en, tlegacy ire lin k- st at e syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in w hich dat ab ases. Lev el 3 rou t ers perf or m sim ilar ly bet w een dom ains. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

NLSP Adjacencies

By exch anging hello p ack et s, a r out er d et er m ines t he r eachabilit y of it s neigh bor s and uses t his inf orm at ion t o est ablish adjacency . Adj acency is a recor d t hat a r out er k eeps about t he st at e of it s conn ect iv it y w it h a neighb or and t he at t r ib ut es of t he neig hbor ing r out er . The rou t er st or es

t hese r ecor ds in it s ad jacen cy dat abase. Adj acency - est ab lish ment pr oced ur es var y d ep en ding up on w h et h er t he r out er is est ablishing and m aint aining ad jacen cies ov er a WAN or a LAN. Est ablishing r out er ad jacen cy over a WAN inv olv es f ir st est ab lishin g t he un derly ing dat a- link connect ion ( det ails depend upon t h e m ed iu m ) . The r out er s t h en exch ange ident it ies b y using t he I PX WAN Ver sion 2 p rot ocol an d det er m ine cert ain op er at ional ch aract er ist ics of t he lin k. Hello • Table of Content s pack et s are ex chang ed , and t h e rou t ers updat e t heir adj acency d at abases. The r out er s t hen •exchan ge b otI ndex h link - st at e p ack et s ( LSPs) descr ibing t he st at e of t heir link s and I PX dat a pack et s Iov nt er e rntet w or k ing Te chnologie s Haa ndbook , Four ioner m aint ains a st at e v ariab le in dicat ing w het her he link . To main t ain WAN link , tth h eEdit r out t heCisco By lin kSystems, is up, dow Inc.n, or init ializin g f or each ad jacency. I f t h e r out er does not hear f r om a neighb or w it hin t he t im e specified in a holding t im er , t he r out er g en er at es a m essag e indicat ing t hatPub t he is dow lish lin er: kCisco Pressn and delet es t he adj acen cy . Pub Dat e: Sep tem ber 1 1, 2 003

WAN h ello packet s enab le rou t ers t o discover each ot her' s ident it y , t o decid e w het her t h ey ar e in I SBN: 1- 58 705 -1 19 -2 t he sam e r out in g ar ea, and t o det erm ine wh et her ot her r out er s and link s ar e oper at ional. A r out erPages: sends11h28ello packet s w hen t he cir cuit is f irst est ab lished, wh en a t im er ex pir es, or w hen t h e cont ent s of t he nex t h ello t o be t ran sm it t ed ar e diff erent t han t h e con t ent s of t h e pr evious hello t r ansm it t ed b y t his sy st em ( and one or m or e secon ds hav e elapsed since t he pr ev ious h ello) . Hello packet s ar e sent as long as t h e cir cuit ex ist s. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cuat tNew ing- edg e t ech nologies. Establishing WAN Adjacency A t yp ical st ar tov uperpvrocedur b et wolog een ies t woessen r out er s (t A anetdwor B) kon WAN lin k als begins witlev h els, t h e lin k in Con cise iew s ofet echn t ial on inga pr ofession at all f rom t he dow n st at e. Rout er A send s a WAN hello indicat ing t h e dow n st at e t o Rout er B, w hich nov ice t o ex pert . chang es it s st at e for t he link t o init ializin g. Rout er B sends a WAN hello w it h a field in dicat ing it s init ializing st at eert os Rout er A. Rout enpor chan it s stlike at e VoI f or Pt he link t o init ializing and sen ds New chapt include cov eragere A oft him t antges t opics and EAP a W AN hello w it h a f ield indicat ing t his t o Rou t er B. Rou t er B chang es it s st at e for t he link t o t he up st at e an d sends a tWAN hellot echn w it hologies a field in g itnsetnew at e.and Finally, Rout er A ch anges it s Cov erag e of cut ing edge likdicat e optinical wor st k ing st or age st at e f or t he link t o u p. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . IMaintaining n t ern et w or k inAdjacencies g Tech nologiesover HandLANs book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing When a .b road , such 2. 3 wEtorher an d olog 8 02.ies 5 Tok g, WAN is enab led on aent . indu st ry Lear ncast howcirtcuit o incor por as at ean int80 er net kinnet g t echn in t en o aRin LAN/ env ir onm rCom out er , t he rou t er begins sendin g an d accept ing hello pack et s fr om ot h er rou t ers on t h e LAN y,and plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit st ar t s t he design at ed r out er elect ion pr ocess. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. The d esign at ed r out er r epr esent s t he LAN as a w hole in t he link - st at e dat ab ase, m ak es r out ing decisions b ehain alf a ofgtreat he werhole, and or ding iginatof esLAN LSPs on WAN behalf ofwtor hek ing, LAN.p This Reader s won ill obt un der st an and n et ar t icuensur lar ly es t h et hat t he size of t he link st at e d at abases t hat each r out er m ust const r uct and m anage st ay w it h in ided on har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov raeasonab le lim it s. b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Period ically , ev er y r out er sen ds a mu lt icast hello packet on t he LAN. The r out er w it h t he h ighest Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy pr ior it y ( a conf igur able p ar amet er ) becom es t he Lev el 1 desig nat ed r ou t er on t h e LAN. I n case of syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich a t ie, t he r out er w it h t he h igher MAC add ress w ins. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Sending LAN Hello Packets

Hello packet s enab le r out ers on t he br oadcast cir cuit t o discov er t h e ident it y of t he ot her Lev el 1 r out er s in t he sam e r out ing ar ea on t hat cir cuit . Th e packet s ar e sent imm ediat ely w hen an y circuit has b een en abled t o a sp ecial m ult icast dest inat ion addr ess. Rout er s list en on t his ad dr ess

for arr iv ing hello pack et s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

NLSP Operation An NLSP r ou t er ex t r act s cer t ain infor m at ion fr om t h e adj acency d at abase and add s locally der ived infor m at ion. Using t his inf or mat ion , t he rou t er con st ru ct s a link - st at e pack et ( LSP) t h at descr ibes it s im m ediat e neighb or s. All LSPs const r uct ed b y all r out er s in t he r out in g ar ea m ak e •up t h e lin k- stTable of Content at e dat abase sf or t he area. •

I ndex

IThe nt e rn et w orspecif k ing Teicat chnologie H a ds ndbook Four th Edit NLSP ion ints en f or ,each r out eriont o m ain t ain a copy of t h e lin k- st at e dat abase an d tBy o Cisco keepSystems, t hese copies sy nchr onized w it h each ot h er . Th e link - st at e dat ab ase is sy nchr onized by Inc. r eliably p r opagat ing LSPs t hr oug hout t he r ou t in g area wh en a rou t er observ es a t op ology chang e. Tw o m et hods ensur e t hat accur at e t op ology - ch ange in for m at ion is p r opagat ed: floodin g Pub lish er: Cisco Press and r eceipt con fir m at ion. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 19 -2 Flooding is inst igat-1ed wh en a r out er det ect s a t op olog y chang e. When su ch a ch ange is d et ect ed, t he rou Pages: t er con 11 28 st ru ct s a n ew LSP an d t ran sm it s it t o each of it s neighb ors. Su ch LSPs are direct ed pack et s on a WAN an d mu lt icast packet s on a LAN. Upon r eceiv ing an LSP, t he r out er u ses t h e seq uence nu mb er in t h e pack et t o d ecide w h et h er t he p ack et is n ew er t h an t he cur r en t copy st or ed in it s dat ab ase. I f it is a new er LSP, t he r out er r et ran sm it s it t o all it s neighb ors ( ex cep t on t he cir cu it ov er w hich t h e LSP w as r eceived) .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of The r eceipt - con fir m at ion p rocess is diff erent for LANs and WANs. On WANs, a r out er r eceiving an essent ial an d cu t t ing- edg e t ech nologies. LSP r ep lies w it h an ack now ledgm ent . On LANs, no ex plicit ack now led gm en t occur s, but t he designat ed r out er per iodically m ult icast s a p ack et called a com p let e sequence n um ber pack et ( CSNP) t he LSPolog ident if ier s and mb er t hat it has in all it s lev d atels, abase for Cont hat cisecont ov erains v iewall s of t echn ies essen t ialsequence t o n et wornu k ing prsofession als at f rom t he ennov t ireice ar tea. Th is en su res t h at ot h er rou t ers can det ect w het her t h ey are out of o ex pert . syn ch r onizat ion w it h t h e desig nat ed rou t er . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

NLSP Hierarchical Addressing NLSP su ppor t s a hier archical ad dr essing schem e. Each r out ing ar ea is ident ified by t w o 32- b it qu ant it ies: a n et w or k ad dr ess an d a m ask . Th is pair of nu mb er s is called an ar ea add ress. Ex pr essed in h ex adecimal, an ex amp le of an area ad dr ess f ollows: •

Table of Content s

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5 0Te 0— This nu er is ,t he nth et w orion k ad dr ess I nt e rn 0 et1w2 or3k4ing chnologie s Hmb a ndbook Four Edit By

f or t his r out in g area. Ever y net w or k nu mb er w it hin t hat area st ar t s w it h t he id en t ificat ion cod e 012 345 . Cisco Systems, Inc. FFFFFF0 0 — This nu mb er is t he m ask t hat ident if ies h ow m uch of t he n et w or k add r ess it self and how mu ch r efer s t o in divid ual n et w or k s w it hin t he ar ea.

Pubr lish er: Cisco ef ers t o t hPress e ar ea

Pub Dat e: Sep tem ber 1 1, 2 003

I n t his I exam le705 area SBN: 1-p58 -1 19ad -2 dr ess, t h e fir st 2 4 b it s ( 01 234 5) id en t ify t h e r out ing ar ea. The r emain in g 8 bit s Pages: ar e u sed t o ident if y ind iv idu al net w or k num b er s w it hin t he rou t ing ar ea ( for ex am ple, 11 28 01 234 5AB, 01 234 5C1 , 01 234 511) . Figur e 46 - 2 h ighligh t s t hese add ressin g concept s w it h t h ree dif fer en t net w or k s in a sin gle ar ea.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Figu r e 4 6 -2 . N LSP Add r esse s Con si st of a N et w or k Addr e ss an d a M a sk essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tAo r en con cept eh en sion and t ion, andarad ional r esou r ceswf or herer st udy . ousu t inre g area can comp hav er as m an y as t hrr et eeen dif ferent eadit add resses, each it h fu a rtdiff ent mask . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Hav in g mor e t h an one ar ea add ress allows t he r out in g ar ea t o be r eor ganized w it h out syst s, ing pr ovid g ions. a m orAn e yr ealist ur eofofartea he ad realw or ld can n et wb or k ing en onm ent sain in .w hich int erem ru pt op erinat com bicinpict at ion dr esses e used w itvir hin a dom pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

NLSP Hello Packets Tw o t y pes of NLSP hello p ack et s exist : WAN hello and Lev el 1 LAN hello packet s.

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WAN Hello Packet • I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Figur e 46 - 3 illust r at es t he field s of a WAN hello pack et . By Cisco Systems, Inc.

Pub lish er: Cisco Press

Figu r e 4 6 -3 . Four t e e n Fi el ds M ak e Up a W AN H el lo Pa ck e t

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

WAN Hello Packet Fields The f ollow in g W AN hello pack et f ield descr ipt ions su mm ar ize each f ield illu st rat ed in Figur e 46 - 3.

Prot ocol I D — I d en t ifies t he NLSP r out in g lay er w it h t he 0x 83 hex n um ber. Le ng t h i ndi cat or — Det er m ines t he num ber of by t es in t he f ixed por t ion of t he h ead er . Mi nor v er si on— Cont ains one possible decimal valu e and is ignor ed on r eceipt . • •

Re ser ve d— Cont ains no d ecim al v alues and is ign ored on receip t . Table of Content s

Pack e t I ndex t y pe ( 5 bi t s) — Cont ains 17 possib le decim al v alues.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

MaSystems, j or v e rsion— By Cisco Inc.

Cont ains one possible decimal valu e.

Re ser ve d— Cont ains no d ecim al v alues and is ign ored on receip t .

Pub lish er: Cisco Press

Pub 1, Sen 2 003ds StDat a te:e Sep ( 2 tem bi tber s) 1—

t h e rou t er' s st at e associat ed w it h t he link ( 0 = u p, 1 = in it ializing ,

1- 58 2 I SBN: = dow n )705 . -1 19 -2 Pages: 11 28

Circui t t ype ( Cct t ype ) — Consist s of 2 bit s. This f ield can h ave one of t he follow in g v alues: - 0 — Reser ved v alu e; ignor e ent ir e p ack et . The u pdat ed- 1edit ion of1 t he est -on selling — Level r outbing ly . all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. - 2 — Level 2 r out ing on ly . ( Th e sen der uses t his link f or Lev el 2 rou t ing. ) Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom h .Level 1 and Lev el 2. ( The sen der is a Level 2 r out er and u ses t h is lin k for nov ice- 3t o—exBot pert Lev el 1 and Level 2 t r af fic.) New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Sou rce IeDof—cut Ser v esedge as t he sy stologies em id enlik t ifier t hen send r ouand t er .st or age Cov erag t ing t echn e optofical et worinkging H old ing tby ime — Cont ains t hew horold ing , ininsecond s,king t o b feorused t he in g rou t er . Aut h ored Cisco Sy st ems, ldw idet imer leader net w or t he fIor n t er n etsend . l eng t h— Det er mHand ines book t he en t ir e leng t hit of etpr , in b yt es, includ in g t he I n t ernPack et w ore kt in g Tech nologies , Four t h Ed iont,he is pack a com ehensive refer ence t hatNLSP header . enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing l Wn AN cir cu I D por — Act as er a net u nique id en ifier olog assigies ned o at his cir WAN cu it wenv henir it is ent . indu stLoca ry . Lear how t o it incor at es int w or kin g ttechn in tt o LAN/ onm creat ed by t h e r out er. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all V a ria bl e le ng t h f ie l d— Consist s of a series of opt ion al fields. net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar LAN e, pr ot Hello ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on NLSP Packets a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tFigur o en su re -con ceptr at comp r ehfield en sion r et en t ion, dit ional e 46 4 illust es t he s ofand a LAN Lev el 1 and helloadpacket . r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ctFigu iv it y an im6pr iciency, help t he eader m ake e in tst elligent - efflds icient r ed 4 -4ov. eAeffLAN Lev e ling 1 H elrlo Pa ck e t mor Consi s of ,1cost 6 Fie decisions for t h eir net w ork s.

•

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing tLevel echnologies. er Packet t he t er mFields s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing 1 LANMast Hello indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all The f ollow in g Level 1 LAN Hello p acket f ield descript ion s sum m arize each field illust r at ed in net w or kin g p rof essionals, r egar dless of ex pert ise. Figur e 46 - 4: Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dwProt ar e,ocol pr ot ocols, v ices olv red . Fu inf or matber. ion is pr ov ided on I D — I and d en tser ifies t he inv NLSP out in gndam lay erent w al it ht ech t he nology 0x 83 hex n um a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su comp r ehDet en sion and trhe et en t ion, adtdit rt her udyer . ( up Lere ngcon t h icept ndi cat or — er m ines num berand of by es ional in t her esou f ixedr ces por ftor ionfuof t he st h ead Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy t o and inclu ding t he LAN I D field) . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and one gu idpossible elines f ordecimal opt im izing emis per fored m ance w ill incr Mi nor v er si on— Cont ains valu esyst and ignor on r eceipt . ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions Re ser forvet hd— eir Cont net wains ork s.no p ossible d ecim al v alues and is ignor ed on r eceipt . Pack e t t y pe ( 5 bi t s) — Cont ains 15 possib le decim al v alues. Ma j or v e rsion— Cont ains one possible decimal valu e. Re ser ve d— Cont ains no p ossible d ecim al v alues and is ignor ed on r eceipt .

N o m u lt i ca st ( N M) ( 1 b it ) — I n dicat es, w h en set t o 1, t h at t h e pack et sen der cannot r eceive t raf fic ad dr essed t o a m u lt icast ad dr ess. ( Fut u r e packet s on t h is LAN m u st be sent t o t he b road cast addr ess. ) Circui t t ype ( Cct Ty pe ) ( 2 b it s) — Can hav e one of t h e follow ing v alu es: - 0 — Reser ved v alu e; ignor e ent ir e p ack et . • •

Table of Content s

- 1I ndex — Level 1 r out ing on ly .

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

- 2 —Inc. Level By Cisco Systems,

2 r out ing on ly . ( Th e sen der uses t his link f or Lev el 2 rou t ing. )

- 3 — Bot h Level 1 and Lev el 2. ( The sen der is a Level 2 r out er and u ses t h is lin k for Lev el 1 and Level 2 t r af fic.)

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Pages: 11 28 Sou rce I D — Cont ains t he sy st em I D of t he send in g rou t er .

H old ing t i m e — Cont ains t he h old ing t imer , in second s, t o b e used f or t he send in g rou t er . Pack e t l eng t h— Det er m ines t he en t ir e leng t h of t he pack et , in b yt es, includ in g t he NLSP header . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essentR— ial an d cu t t inge t echdnologies. Cont ains no edg p ossible ecim al v alues and is ignor ed on r eceipt . P rior it y ( 7 b it s) — Ser v es as t he p rior it y associat ed w it h b ein g t h e LAN Level 1 d esignat ed Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom r out er . ( Higher n um ber s hav e high er pr iorit y . ) nov ice t o ex pert . LA N I D — Cont ains t he sy st em I D ( 6 by t es) of t he LAN Lev el 1 desig nat ed rou t er , f ollowed New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP by a field assign ed by t hat design at ed r out er . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age V a ria bl e le ng t h f ie l ds— Consist s of a series of opt ion al fields. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: • •

What is t h e pur pose of a Lay er 2 r ou t er wit h in t he NLSP hierar chical r out ing Table sch emof e?Content s I ndex

I nt e rn et 2 w :or k ing Te chnologie H a ndbook th Edit How long ar es hello p ack, Four et s sen t afion t er By

a r out er is in it ialized and r eaches a fully

fu nctInc. ional st at e? Cisco Systems, 3:

What t y pe of LSPs ar e sent ov er a WAN—d ir ect ed or m u lt icast ?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 47. Open Shortest Path First Obj e ct i ve s • •

Table of Content s

Discuss t he u se of aut onom ous sy st ems. I ndex

I nt e rn Descr et w or kibe ing Te chnologie Four t he use of st hH ea ndbook Sor t s ,Pat h thFirEdit st ion alg orit h m. By Cisco Systems, Inc.

Discuss t he ad dit ional f eat ur es of OSPF. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background Op en Shor t est Pat h Fir st ( OSPF) is a r out ing pr ot ocol d ev eloped f or I nt er net Pr ot ocol ( I P) net w or ks by t h e I n t erior Gat ew ay Prot ocol ( I GP) w or kin g g rou p of t he I nt er net Engineer in g Task Force ( I ETF) . The w or king g rou p w as for m ed in 198 8 t o design an I GP based on t h e Shor t est •Pat h Fir st ( SPF) Tablealgor of Content it hm sf or use in t he I n t er net . Sim ilar t o t he I nt er ior Gat ew ay Rou t ing •Pr ot ocol ( I GRP) I ndex , OSPF w as cr eat ed because in t he m id- 19 80s, t h e Rou t in g I n for m at ion Pr ot ocol I( nt rn et or kincreasingly ing Te chnologie s H a ndbook ion RIeP) wwas incapab le of, Four ser vthinEdit g lar ge, h et er ogeneous in t er n et w or k s. This chapt er exam ines t h e OSPF By Cisco Systems, Inc. r out in g env ir onm en t , un der ly ing r out ing algor it hm , an d general pr ot ocol com ponent s. Pub lish er: Cisco Press

OSPF w as d er iv ed f rom sev er al resear ch ef for t s, includ in g Bolt , Ber anek , and New man 's ( BBN' s) Dat e: Sep tem ber 1 1, 2 003 SPFPub algor it hm developed in 1 978 for t he ARPANET ( a landm ar k pack et - sw it ching net w or k I 1- 58 705ear -1 19 dev elopSBN: ed in t he ly-2197 0s by BBN) , Dr . Rad ia Perlm an' s r esear ch on f ault - t oleran t Pages: 11 28 br oadcast ing of r out ing inf orm at ion ( 19 88) , BBN's w or k on ar ea r out ing ( 19 86) , and an ear ly v er sion of OSI ' s I nt er m ed iat e Syst em - t o- I nt er mediat e Sy st em ( I S- I S) r out ing p rot ocol. OSPF h as t w o p rim ar y char act er ist ics. Th e fir st is t h at t h e pr ot ocol is open, w hich m eans t h at it s specif icat ion is in t he p ublic d omain. The OSPF sp ecificat ion is pub lished as Requ est For Com ent sed( RFC) 12 47. Theb est secon d p rinallcipal char net act er ist ic is rtef hat OSPFpis based on t he SPF The umpdat edit ion of t he - selling in- one w ork ing erence rov ides cover age of algor it hm , w hich somet im es is ref er r ed t o as t h e Dijk st r a algor it hm , n amed for t he p er son essent ial an d cu t t ing- edg e t ech nologies. credit ed w it h it s cr eat ion. OSPFCon is acise link ov - ster atveiew r out ingt echn pr ot ocol t h atessen callst ial for t tohe sending - st at eals advatert en t sf rom s of olog ies n et wor k ingofprlink ofession allisem lev els, ( LSAs) t o all ot her r out ers wit h in t he sam e hierar chical ar ea. I n for m at ion on at t ach ed int er faces, nov ice t o ex pert . m et rics used, an d ot her v ariab les is includ ed in OSPF LSAs. As OSPF r out er s accu mu lat e lin kst at e New inf or mat ion use cov t h eerag SPFealgor hm t ant t o calcu lat like e t heVoI shPort est EAP p at h t o each n ode. chapt er, st hey include of imitpor t opics and As a lin k-erag st at ee rou t ing pr ot ocol,t echn OSPF cont r ast it hical RI P anwor d I GRP, w hich arage e d ist an ce- v ect or Cov of cut t ing edge ologies lik se w opt n et k ing and st or r out ing pr ot ocols. Rou t er s r un ning t he dist ance- v ect or algor it hm send all or a por t ion of t heir r out ing Autt ab h ored les in byr out Cisco ingSy - upd st ems, at e mwessages or ldw idet oleader t heir neighb in net wors. or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Routing Hierarchy Unlike RI P, OSPF can operat e w it hin a hier archy . Th e larg est en t it y w it hin t he h ier ar ch y is t he aut on om ous syst em ( AS) , w hich is a collect ion of n et w or k s un der a com m on ad min ist r at ion t hat shar e a com m on rou t ing st rat egy . OSPF is an in t r a- AS ( int er ior gat ew ay ) r out in g p rot ocol, •alt hou gh it isTable of le Content s capab of receiv ing r out es fr om an d send in g rou t es t o ot h er ASs. •

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IAn nt eAS rn etcan w or kbe ing div Te chnologie ndbook , Four th Edit ion ided in t os Haa nu mb er of areas, w hich are g r oups of cont ig uous n et wor k s and at t ached host s. Rou t er s w it h m ult iple int er faces can p ar t icipat e in m ult ip le areas. These r out er s, By Cisco Systems, Inc. w hich are called Ar ea Bor der Rou t ers, m aint ain sep ar at e t opological d at abases for each area. Pub lish er: Cisco Press A t opological dat ab ase is essen t ially an ov erall pict ur e of net w or ks in r elat ion sh ip t o r out er s. The Pub Dat e: d Sep ber 1 1, 2 003 t opolog ical attem abase cont ains t he collect ion of LSAs r eceiv ed f rom all r out ers in t h e same area. I SBN: 158 705 -1 19 -2 Becau se rou t er s w it h in t h e same ar ea shar e t h e same in for m at ion, t hey hav e ident ical t opolog Pages: ical d 11at 28abases.

The t er m dom ain som et imes is u sed t o d escr ibe a p or t ion of t h e net w or k in w h ich all r out er s hav e ident ical t op ological dat ab ases. Dom ain is fr equent ly u sed int er ch angeably w it h AS. An ar ea' s t opolog y is inv isible t o ent it ies out side t h e ar ea. By keeping ar ea t opologies separ at e, The u pdat ed edit b est in- one net w ork ef erence p rov OSPF p asses lession r ouof t intghet raf fic- tselling han it allw ould if t he AS w ering e nrot p art it ion ed .ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Ar ea par t it ioning cr eat es t w o diff erent t y pes of OSPF r out in g, d ep en ding on w het her t he sou rce and t h e dest in at ion ar e in t he sam e or diff er ent areas. I nt r a- ar ea r out ing occur s w hen t he sour ce Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom and dest inat ion ar e in t he sam e area; int erar ea r out in g occur s w hen t hey ar e in diff erent ar eas. nov ice t o ex pert . An OSPF back bone is responsible f or dist r ibut in g r out in g in for m at ion bet w een areas. I t con sist s New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP of all Ar ea Bor der Rou t er s, net w or k s not w holly con t ained in any area, an d t heir at t ached r out erCov s. Figur 1 sh owsedge an ex am ple of an lik inet ern w ornketwwor it h ksev eragee 47 of -cut t ing t echn ologies optetical ingeral and ar steas. or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

eor4k7in-1 . Annologies OSPFHand AS book Consist u lt ipla ecom Arpreehensive as Li nkrefer e d by I nFigu t ern etrw g Tech , Fourst hof Ed itMion , is enceRou t hat t e r s enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t he f ig ur e, r out ers 4, 5 , 6, 1 0, 1 1, an d 1 2 mak e u p t h e back bone. I f Host H1 in Area 3 w ant s n t send ern et w k in g Tech nologies t hetEd ion ,t is comerpr1ehensive tI o a or packet t o Host H2 inHand Ar eabook 2, t h, eFour pack isitsen t o aRout 3, w h ich refer for w ence ar ds t hhat e pack et w or g psend r ofessionals t o unt oderst an dRout im plem contf or em intper net ork ing tenables o Rout ernet 1 2, wkin hich s t he packet Rouand t er 11. er 1 en 1 tthen wpor ardar s tyhe ack etwalon g the t echnologies. er tder he tRou er mts, s, t sen echndsologies, anet d devices in rtaoday ' s rnet back bone t o ArMast ea Bor er con 10,cep whtich t h e pack t hr oug h used t w o int ar ea outwerork s ing ry .9 Lear howert o7 )incor porf orw at e ar intded er net or kinH2. g t echn olog ies in t o a LAN/ WAN env ir onm ent . (indu Roust t er and nRout t o be t owHost Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and bspeed, The ackb one t h isit self bookisisana OSPF com plet ar ea, e anso d uall p- bt oack d at bon e reefrer out ence er s use t o t he t het op sam icset hat p rocedur are essen es and t ial t o all net w or algor it hm kinsg tporof m essionals, ain t ain rourtegar ing infor dlessmof at ion ex pert w it ise. h in t he back bone t hat any ar ea r out er w ould. The back bone t opology is inv isible t o all in t r a- ar ea rou t ers, as are in divid ual ar ea t op olog ies t o t h e Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e back bone. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a beas Ar r oad can r ang be edefined of int egr inalsuch sy staem w sayand t hatserv t heices, backinbone clud ing is not detcon ailed t iguou descrs.ipt I nion t hs, is rev case, iewback quest bone ions t o en su re connect ivitcon y mu cept st be comp r est r eh ored en sion t hr oug andh rvir et ten ual t ion, lin ks. andVir adt ual dit ional lin ks rare esouconf r ces igur f ored fu bet rt her w een st udy any . Cov erag back bone e is roualso t er sext t h at endshar ed ne ot a only link ttoo anew nonnbackb et worone k ingarconcep ea andt s, f unct bution also ast oif old t hey er ,wlegacy ere dir ect systs. link em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease AS b ord erit yrou OSPF lear help n about ior r out es t hr ou eghinex t er ior ,gat ew-ay pr ot ocols pr odu ct iv ant ers d imruprnning ov e eff iciency, ing text he er r eader m ake mor t elligent cost eff icient (decisions EGPs) , sufor ch tas Extnet er ior Gat h eir w ork s. ew ay Pr ot ocol ( EGP) or Bord er Gat eway Prot ocol ( BGP) , or t hr ough conf ig ur at ion in for m at ion. For m or e inf orm at ion abou t t h ese pr ot ocols, see Ch apt er 41 , " Bor der Gat ew ay Pr ot ocol."

SPF Algorithm The Shor t est Pat h Fir st ( SPF) r ou t ing alg or it hm is t h e basis for OSPF oper at ions. When an SPF r out er is pow er ed u p, it in it ializes it s r out in g- pr ot ocol d at a st r uct ur es and t h en w ait s f or indicat ions fr om low er - lay er pr ot ocols t hat it s int er faces are fun ct ion al. •

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•Aft er a r out erI ndex is assur ed t h at it s int er f aces ar e f unct ioning , it u ses t h e OSPF Hello pr ot ocol t o Iacquir nt e rn etewneigh or k ingbor Te chnologie H aendbook s, w hichs ar r out er, Four s w itthh Edit in t ion erf aces t o a com m on net w ork . Th e r out er sen ds hello pack et s t o it s neig hbor s an d receiv es t heir hello pack et s. I n ad dit ion t o helping acqu ir e By Cisco Systems, Inc. neighb or s, hello packet s also act as k eepaliv es t o let r out er s k now t hat ot her r out er s ar e st ill fu nct ional. Pub lish er: Cisco Press

Dat e: Sep tem berw1or 1, ks 2 003 On Pub m ult iaccess net ( net w ork s sup por t ing m ore t han t w o r out er s) , t he Hello p rot ocol elect s I SBN: 158 705 -1 19 -2 a d esign at ed r out er an d a back up desig nat ed rou t er. Amon g ot her t hing s, t he d esign at ed r out er is r espPages: onsib11 le28for g en er at ing LSAs for t he ent ir e m ult iaccess net w or k. Design at ed r out er s allow a r ed uct ion in n et w or k t r aff ic and in t he size of t h e t opological dat abase.

When t he lin k- st at e d at abases of t w o n eigh bor ing rou t ers are sy nchr onized, t he r out er s ar e said t o be adj acen t . On m ult iaccess net w or ks, t he designat ed r out er det er mines w h ich r out er s sh ould becom e adjacent . Topological dat ab ases ar e sy nchr onized b et ween pair s of adjacent r out ers. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Adj acencies cont r ol t h e dist r ib ut ion of rou t ing- p r ot ocol packet s, w hich ar e sent and r eceiv ed only essent ial an d cu t t ing- edg e t ech nologies. on adj acencies. Each Con r outcise er per sends anolog LSA pr ovid e infor mwor at ion on pr a ofession r out er 's als ad jacencies or tforom oviodically er v iew s of t echn iest oessen t ial t o n et k ing at all lev els, inf ormnov otice her tsowex hen a r out er 's st at e chan ges. By comp arin g est ablished ad jacencies t o link pert . st at es, failed r out er s can be det ect ed q uick ly , and t he net w ork ' s t opology can be alt er ed app rop riat chapt ely . From t he t opcov ological en er at ed fr omVoI LSAs, each New er s include erag edat of abase im por tgant t opics like P and EAProu t er calculat es a shor t est - pat h t r ee, w it h it self as r oot . Th e shor t est - p at h t r ee, in t ur n, yields a rou t ing t able. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Packet Format All OSPF p acket s b eg in w it h a 2 4- by t e h ead er , as illust r at ed in Figur e 47 - 2.

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4 7 -2 . O SPF Pa ck et s Con si st of N in e Fi el ds

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The f ollow in g d escr ipt ions sum m ar ize t he h ead er field s illu st rat ed in Figur e 47 - 2. e rsion num t ifies t he allOSPF ver sion u ork sed.ing r ef erence p rov ides cover age of The uV pdat ed edit ionbeofr— t heI dben est - selling in- one net w essent ial an d cu t t ing- edg e t ech nologies. Ty pe — I d en t ifies t he OSPF pack et t y pe as on e of t he f ollow in g: - Hov e llo— Ests ablish es and m ain t ainst ial n eigh r elat ionships. Con cise er v iew of t echn olog ies essen t o nbor et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . - D a t ab ase de scr ipt i on— Descr ibes t he cont en t s of t he t opological dat ab ase. Th ese New chapt m essages er s include ar e exchan cov erag ged e of whim enpor an t ant adj acen t opics cy like is inVoI it ialized. P and EAP Cov erag of- st cutatting t echn ologiesslik e opt ical k ingical and stabase or age f rom neig hbor - Lienk e reedge qu est — Request pieces of t hneettwor opolog d at r out er s. These messag es are ex chang ed af t er a r out er d iscover s ( b y ex am ining Aut h ored byaseCisco Sy st ems, or et ldw leader king f or tdhe I n t er n ar et .e out d at ed . dat ab d escrip t ion pwack s)ide t h at p art sinofnet it swt or opological at abase I n t ern et w or-kLi innk g Tech bookonds , Four , is com pr ehensive t hat also - st a nologies t e up da tHand e— Resp t ot ha Ed linitk-ion st at ea r equest p acket . Threfer ese ence m essages enables netar w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w orkaing e used f or t h e r eg ular disper sal of LSAs. Sev er al LSAs can be in clud ed w it hin t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing single link - st at e up dat e p ack et . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w-itLihnk new u ck pdat ed lchapt s ton it y ,ledges st or age, netdat w or g, et scalabilit y, - st an a t ed a n ow ed gmeren — secur Ack now linkopt - st ical at e up e kpinack s. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Pack e t l eng t h— Specif ies t h e pack et len gt h , including t h e OSPF header , in by t es. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dwRout ar e, er pr ot and ser vt he ices invce olvof edt.hFu ndam ent I Docols, — I d en t ifies sour e packet . al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su r eht he en sion en ttion, and et adbelong dit ionals. r All esou r ces pack f or fuetrtsher udy . ed Arre eacon I D cept — I d comp en t ifies ar eaand t o wr et hich he pack OSPF ar estassociat Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy w it h a single ar ea. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals Che ck sum oper —atChecks e. Tools t he and entgu ir eid pack elines et f or cont opt ent imsizing f or any systdam em age per for sufmfer ance ed in w ill t r ansit incr ease . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Au t he pes.— Cont ains t he au t hent icat ion t yp e. All OSPF pr ot ocol ex ch anges ar e decisions forntt hica eirt ion net wt york aut h en t icat ed . The au t hent icat ion t yp e is config ur able on per- area b asis. Au t he nt ica t ion— Cont ains aut hent icat ion inf orm at ion. D a t a— Cont ains en cap su lat ed u pper - layer inf or mat ion .

•

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Additional OSPF Features Add it ion al OSPF f eat ur es in clu de equal- cost , m ult ipat h r out in g, an d r ou t ing based on up perlay er t yp e- of - ser v ice ( TOS) r equest s. TOS- based rou t ing supp ort s t hose up per- lay er pr ot ocols t hat can sp ecify p ar t icu lar t yp es of ser vice. An applicat ion, f or exam p le, m igh t specif y t h at •cer t ain dat a is Table of Content s ur gent . I f OSPF has h ig h- pr ior it y link s at it s disp osal, t hese can be used t o •t r anspor t t heI ndex u rg en t d at agr am . I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

OSPF sup por t s one By Cisco Systems, Inc. or m ore met r ics. I f on ly one m et ric is u sed, it is consider ed t o be ar bit r ar y, and TOS is not su ppor t ed. I f m or e t han on e m et r ic is u sed, TOS is op t ionally su ppor t ed t hr oug h t he use of a separ at e m et ric ( an d, t herefor e, a separ at e r out in g t able) f or each of t he eigh t Pub lish er: Cisco Press com binat ions cr eat ed b y t he t h r ee I P TOS b it s ( t he d elay , t h rou ghp ut , an d reliabilit y bit s) . For Pub Dat e: Sep tem ber 1 1, 2 003 exam ple, if t h e I P TOS bit s specif y low d elay , low t h rou ghp ut , an d high r eliabilit y , OSPF 1- 58 705t-1 calcu latI SBN: es r ou t es o 19 all-2 d est inat ion s based on t h is TOS d esignat ion . Pages: 11 28

I P sub net m asks are in clu ded w it h each ad ver t ised dest in at ion, enab lin g v ar iable- len gt h su bnet m asks. Wit h v ar iab le- lengt h sub net m ask s, an I P net w ork can be b r oken int o m an y su bnet s of v ariou s sizes. This p r ovides n et w or k adm inist r at or s w it h ex t r a n et w or k - config ur at ion f lex ibilit y . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: • •

When using OSPF, can you hav e t w o areas at t ach ed t o each ot her w her e only on e of Content s AS Table h as an int erf ace in Ar ea 0 ? I ndex

I nt e rn2 et:w orAr k ing a ndbook , Four th Edit ionD , ea Te 0 chnologie con t ainss fHive r out er s ( A, B, C, By

and E) , and Area 1 cont ain s t hr ee r out er s ( R, S, and T) . Wh at r out er s d oes Rout er T kn ow exist s? Rou t er S is t h e ABR. Cisco Systems, Inc. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 48. Open System Interconnection Routing Protocols • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Under st and t he b ack gr oun d an d role of ES- I S, I S- I S, an d I D RP.

By Cisco Systems, Inc.

Descr ibe t he gener al oper at ion of ES- I S. Pub lish er: Cisco Press

ExDat plain t he S- 1I S Pub e: Sep tem Iber 1, r2out 003 in g

archit ect ur e.

I SBN: 1- 58 705 -1 19 -2

Ex am ine t h e use of I S- I S for CLNS rou t ing and I P r out ing . Pages: 11 28

Descr ibe t he I S- I S pack et t y pes and f orm at s. Look at som e of t he ad dit ional f eat ur es su ppor t ed by I S- I S. ibeedit t heion gener al oper ion of allI D RP. The uDescr pdat ed of t he b estat - selling in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. I nt er mediat e Syst em –t o–I nt er m ed iat e Syst em ( I S- I S) is b ased on w ork orig in ally done at Digit al Eq uipm ent Cor por at ion ( D igit al) f or DECnet / OSI ( DECn et Phase V) . I S- I S or igin ally w as dev elop edcise t o rou in IsSO nect ionies less Net w orkt oProt CLNP) net w ork s. at A ver has since Con ov ert ev iew of Con t echn olog essen t ial n etocol wor k(ing pr ofession als all sion lev els, f rom been nov cr eat edt ot hex atpert sup.por t s bot h CLNP an d I P net w ork s; t his v er sion u su ally is called I n t eg rat ed ice I S- I S ( it also has been called D ual I S- I S) . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Op en Sy st em I n t er connect ion ( OSI ) r out in g p rot ocols ar e sum m ar ized in sev er al I n t er nat ion al Or ganCov iz aterag ion feorofStcut and t ing ardedge izat ion t echn ( I SO) ologies docum lik ent e opt s, ical includ n eting worI SO k ing10and 589st , or w hich age defines I S- I S. The Am er ican Nat ional St andar ds I n st it u t e ( ANSI ) X3 S3. 3 ( net w ork an d t ran sp or t lay er s) Aut h ored Sy st w orbehind ldw ide Ileader in ar net w or ion kingoff or n t er n etI SO . d ocu ment s com mit t ee w as by t h eCisco m ot ivat inems, g f or ce SO st and dizat I S-t he I S. I Ot her include I SO 95 42, wh ich def in es ES- I S, and I SO 1074 7, w h ich defin es I DRP. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables or kin g ap rcom ofessionals im plem emOSI por ar er net orkThese ing The I SO net devweloped plet e suitt oe un of derst r out inand g p an rotdocols f or en uset cont in t he pryotint ocol suitwe. t echnologies. heI nt er m s,ediat con cep t echn ologies, anI dS,devices inain t oday ' sing netPr w ork ing include End SyMast st emer–tto– t erm e Syt s, st em ( ESI S) , I Sand I nt used er dom Rout ot ocol st ry Learchapt n how o incor por at e int er net w or kin ologofies in t o pr a ot LAN/ WAN envcov ir onm (indu I DRP) . .This er tad dr esses t he b asic operat iongst echn of each t hese ocols. Also er edent is. plet e wyitspecif h newican u pdat chapt s on secur it yof , st or age, opt icalion net or kex in g, scalabilit y, I S tCom er min olog t odOSI roued t ing anderan over v iew r out in g operat .w The t ension of I St h isonly bookConn is a ect com plet e Net an dwuork p- t od at e r ef er encebtut o talso he t op hat areisessen ial t o all tand o suspeed, ppor t not ionless Ser v ice ( CLNS) I P ics nettw or ks descrtibed, netrw or kin rof ur essionals, r egar dless of avoid ex pertance ise. and MPLS t r aff ic en gineerin g. int odu cin g pf eat es su ch as b lack h ole Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

OSI Networking Terminology The w or ld of OSI net w or k in g uses som e specif ic t er minolog y, su ch as end syst em ( ES) , w h ich r ef ers t o any nonr out in g n et wor k n ode, and int erm ediat e syst em ( I S) , w h ich r ef ers t o a rou t er. These t erm s f or m t he basis of t he ES- I S and I S- I S OSI p rot ocols. The ES- I S pr ot ocol let s ESs •and I Ss discover Table each of Content s The I S- I S pr ot ocol p rov ides r out ing b et w een I Ss. ot her. •

I ndex

IOt nth e rn w or k ing sH ndbook , Four Editde ionar ea, dom ain, Level 1 r out ing , and Lev el 2 er etim p ort anTet chnologie OSI net w ora king t er m s th inclu rByout ing . An ar ea is a gr oup of cont igu ous n et w or k s and at t ached host s t h at is d esignat ed as an Cisco Systems, Inc. ar ea by a net w or k adm inist r at or or m anag er . A dom ain is a collect ion of con nect ed ar eas. Rou t ing dom ains pr ov ide f ull conn ect iv it y t o all end sy st em s w it hin t hem . Lev el 1 r out ing is Pub lish er: Cisco Press r out ing w it hin a Lev el 1 ar ea, and Lev el 2 r out ing is rou t ing bet w een Lev el 1 ar eas. Figur e 48 - 1 Pub Dat e: Sep tem ber 1 1, 2 003 illust rat es t he r elat ion sh ip b et w een ar eas and d omains and show s t he lev els of r out in g bet w een I SBN: 1- 58 705 -1 19 -2 t he t w o. Pages: 11 28

Figu r e 4 8 -1 . Ar ea s Exi st W it hi n a La r ger Dom a in a nd Use Lev el 2 Rou t i ng t o Com m un icat e The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Overview of OSI Routing Operation Each ES liv es in a par t icular ar ea. OSI r out in g b eg ins w hen t he ESs discov er t h e nearest I S by list en in g t o I S h ello ( I SH) m essage pack et s. When an ES w ant s t o send a p ack et t o anot h er ES, it sends t he p ack et t o one of t h e I Ss on it s dir ect ly at t ach ed net w or k. The r out er t h en look s up •t he dest in at ion Table adof drContent ess an sd f or w ard s t he p acket alon g t he best r out e. I f t h e dest inat ion ES is on •t he sam e subI ndex net w ork , t h e local I S k now s t h is fr om list en in g t o ES hello ( ESH) m essages and Ifor nt ewrn w ort he k ingpack Te chnologie s H ariat ndbook Four th ionmig ht pr ovide a r edirect m essag e back t o t he aretds et app rop ely ., The I SEdit also sour ce tSystems, o t ell it Inc. t hat a m or e- direct r ou t e is av ailab le. By Cisco I f t he d est inat ion add ress is an ES on an ot her sub net w ork in t h e sam e ar ea, t h e I S k now s t he Pub lish er: Cisco Press corr ect r out e and for w ar ds t h e packet appr opr iat ely. I f t h e dest inat ion addr ess is an ES in e: Sep tem ber 1 1, 2 003 anotPub h erDatarea, t he Lev el 1 I S send s t he packet t o t h e near est Level 2 I S. Forw ar din g t hr ough I SBN: 58 705 -1 19 -2 Lev el 2 I Ss 1cont in ues un t il t he p acket r eaches a Lev el 2 I S in t he d est inat ion ar ea. Wit hin t he Pages: dest inat ion 11 ar28 ea, I Ss f or w ard t h e packet along t he b est pat h unt il t he d est inat ion ES is r eached.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ES-IS ES- I S is an OSI pr ot ocol t h at def in es how end sy st em s ( host s) and int erm ediat e sy st em s ( r out er s) learn abou t each ot her, a pr ocess kn own as conf igur at ion. Conf igur at ion m ust h appen befor e r out in g bet w een ESs can occur . •

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•ES- I S is mor e I ndex of a discov ery pr ot ocol t han a rou t ing pr ot ocol. I t dist ing uishes am ong t hr ee Idif nt fer e rn en et wt or ing Te s H akndbook , Four thpoin Edit ion t ykpes ofchnologie subn et wor s: p oin t - t ot , br oadcast , an d g en er al t opology ( see Figur e 48 2) . By Cisco Systems, Inc. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 Figu r e 4 8 -2 . ES-I S Ca n Be De pl oye d i n Poi nt -t o-Poi nt , Br oadcast , a nd I SBN: 1- 58 705 -1 19 -2 Ge ne r al Topolog y Su bne t w or k s Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Point - t o- point su bnet w or ks, such as WAN ser ial link s, pr ovid e a p oin t - t o- poin t link b et w een t w o syst em s.hBroad cast subnet w ems, or k s, w suorchldw aside Et her net and I EEE 02. 3f or , dir ectI nat er single Aut ored by Cisco Sy st leader in net w or 8king t he n et . p hy sical m essage t o all nod es on t he subn et wor k . Gener al t op olog y subn et w or k s, su ch as X. 2 5, sup por t an ar bit ber of sy st emHand s. Unbook lik e b, road bnet w or s, how ev er , t herefer costence of ant hat n- w ay I n t ern et rwary or knum in g Tech nologies Fourcast t h Edsu it ion , is a kcom pr ehensive tenables r ansm ission scales dir ect ly w it h t he su bnet w or k size on a gener al t opology su bnet w or k. net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com pletConfiguration e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, ES-IS and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. ES- I S conf igur at ion is t he pr ocess wh er eby ESs and I Ss discov er each ot h er so t hat r out ing bet w een ESs canain occur . ES-erI Sun con ratding ion inf ion WAN is t r ansm at rpeg intly er tvals Reader sw ill obt a g reat derfigu st an of orm LANatand n et witort ed k ing, arular t icu lar he thar hr ou gh ESHs and I SHs. ESHs ar e gener at ed b y ESs an d are sent t o ev er y I S on t h e subn et w or dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided onk . IaSHs ar e gener at ed by I Ss and are sent t o all ESs on t he su bnet w or k. These h ello messages b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions pr e int encomp ded t or eh conv ey t he et wor an d ad n etdit wor k lay er addr t h e st syst em t o im enarily su re ar con cept en sion andsubn r et en t ion,k and ional r esou r cesesses f or fuofrt her udy . s tCov haterag gener at e t h em . e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Wher e possible, ES- I S at t em pt s t o send configu r at ion inf or m at ion sim ult aneously t o man y pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease syst em s. On br oadcast sub net w ork s, ES- I S hello m essages ar e sent t o all I Ss t hr oug h a special pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient m ult icast add ress t hat designat es all end sy st em s. When oper at ing on a gener al t opolog y decisions for t h eir net w ork s. subn et w or k , ES- I S generally d oes n ot t r an sm it con figu rat ion inf orm at ion because of t he h igh cost of m ult icast t r ansm issions.

ES-IS Addressing Information

The ES- I S conf ig ur at ion pr ot ocol conv ey s bot h OSI net w or k layer add r esses and OSI subn et wor k add resses. OSI net w ork lay er add resses id en t ify eit her t he net w ork ser vice access poin t ( NSAP) , w hich is t he int er face b et w een OSI Lay er 3 and Lay er 4, or t he net w or k ent it y t it le ( NET) , w hich is t he net w ork lay er ent it y in an OSI I S. OSI sub net w or k addr esses, or sub net w ork p oint of at t ach m en t ( SNPA) addr esses, ar e t he p oint s at wh ich an ES or I S is p hy sically at t ached t o a su bnet w or k. The SNPA ad dr ess u niquely •ident if ies each Table sy st ofem Content at t ached s t o t h e su bnet w or k. I n an Et hern et net w or k, for ex am ple, t he - bit Med ia Access Con t rol ( MAC) addr ess. Part of t he con figu rat ion inf orm at ion •SNPA is t h e 48 I ndex it tored b yTeESI S is t sh He aNSAPSNPA orion NET- t o- SNPA m ap ping. It rntansm e rn et w k ing chnologie ndbookt, oFour th Edit By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IS-IS Or iginally sup por t ing OSI CLNS net w or k s, I S- I S has been ex t ended t o also su ppor t rou t ing of classless I P net w ork s. This ex t ended ver sion is called I nt egr at ed I S- I S or somet im es Dual I S- I S. •Regar dless ofTable Content t he of n et w or k st y pe su ppor t ed, I S- I S is a link - st at e pr ot ocol and , t her efor e, sh ar es •m any of t h e Iadv ndex ant ag es of OSPF over d ist an ce- v ect or - b ased pr ot ocols, su ch as I P RI P. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

IByt pCisco rov ides f ast conv er gence an d r ap id f lood ing of net w ork ch anges. I t sup por t s a hier ar chical Systems, Inc. r out ing design t hr oug h t he use of ar eas, w hich p rov ides scalab ilit y . Ad dit ionally, t his pr ot ocol has been enhan ced t o in cr ease it s flexib ilit y , such as for use as t h e I n t erior Gat ew ay Prot ocol Pub lish er: Cisco Press ( I GP) in n et w or k s using Mult ip rot ocol Label Sw it ching ( MPLS) t r aff ic engineer in g ( TE) . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 Integrated IS-IS

As m ent ioned, I S- I S was ex t ended t o su ppor t I P r out ing in addit ion t o CLNS. I P sup por t is defin ed in RFC 1 195 . This p rot ocol is popu lar w it h lar ge ser vice pr ov iders and oft en is used in pu re I P- on ly net w ork s. I nt egr at ed I S- I S can sup por t b ot h I P and CLNS net w or ks eit her The pdat edit ionr of he. Ther b est -eselling all- in-f or one w or orkk ing ef erence p rov ides age of singuu lar ly ed or concur enttly is no need a nnet et w t o rrun t w o com plet ely cover in dependent essent ial an d cu t t ingedg e t ech nologies. r out ing pr ot ocols and associat ed cont r ol plan es t o supp ort bot h OSI and I P t r aff ic. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

IS-ISnov Routing ice t o ex pert Architecture . Support

er s include of im por ant ht opics likeofVoI P andA EAP I S- I SNew suppchapt ort s hierar chical cov r outerag ing ed esign t hr toug t he use ar eas. lar ge n et w or k is d iv ided int o sm aller ar eas. I S- I S r out er s t h at r out e wh olly wit h in an ar ea ar e called Lev el 1 r ou t er s. I SCov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age I S r out er s t hat r out e b et ween areas ar e called Lev el 2 rou t er s. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The I S- I S b ackb one is not a sing le area 0 as in OSPF. I t is t he g rou ping of all cont igu ously connect 2 r out er s. Each Levbook el 2 ,r out ert hr esides only a sin ar ea, but ay hav e link s I n t ern eted w orLev k inel g Tech nologies Hand Four Ed it ionin, is a com prgle ehensive refermence t hat tenables hat connect t o a Level 2 r out er in anot h er ar ea or areas. Not e t h at t h e ar ea bor der is not e net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w orkt hing Lev el 2 rou t er , b ut t he link b et ween t he Lev el 2 rou t ers. Figur e 48 3 illust r at es t he I SI S t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing hier induarchy st ry . .Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

Figu r e 4 8 -3 . I S- I S Rout in g Ar ch it ect ur e

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . GenerNew ally , chapt Lev eler1sr include out ers kn owerag only t h eimnet kint opics g in forlike m atVoI ionPwand it hinEAP t h at ar ea. I f a Lev el 1 cov e of porwt or ant r out er cannot r out e a pack et using t he in for m at ion w it h in t h e ar ea, it sen ds t h e pack et t o t he closest Lev el 2e rof out er,t ing w hich t h ten r out es it t olikteh eopt app rop riat e area. At t he est inat ion ar ea, t he Cov erag cut edge echn ologies ical n et wor k ing and st ord age pack et is t hen for w ar ded by t h e Level 1 r out er s f or t hat ar ea. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I f a Lev el 1/ 2 r out er is conn ect ed t o an ot her ar ea, it alert s t he Lev el 1 r out ers in it s ow n ar ea by I n t ern set t in gettw heorat k in t ached g Techbit nologies in t h e Hand r out ing book adv , Four er t isem t h Ed enitt .ion Lev , is el a1 com rou tpr ers ehensive see t hisrefer and ence kn owt hat t hat t he enables Lev el 1/ 2net r out w orerkin can g pbe r ofessionals used t o r each t o unnet derst w orand k s out an dside im plem t h e cur en trent contar em ea. por I narI yntint egreratnet edwI ork S- I ing S, t he echnologies. Level 1 / 2 Mast rou t er er orig t he in t er atm ess,an con I Pcep defau t s, tltechn r outologies, e in t o itan s ow d devices n ar ea. used I n Figur in teoday 48 - 3, ' s net Rout w ers ork ing 1A indu st and 1Brybot . Lear h set n how t h e at t ot ached incor por b itatan e int d/ or er net or iginat w or kin e g default t echn olog r out ies es tin o t ohea ot LAN/ h er WAN r ou t er env s in ir onm Ar eaent 1.. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Lev 2 rou tter s kbook now is only abou t te h eanint area n ot t h et o r out in ics t heir oware n area. andelspeed, h is a com plet d er u pt o- drou at et es, r ef er ence t heest op t hat essenLev t ialelt o2 all rnet outwer s should not be conf igur ed in an OSI only n et w or k , because all OSI rou t er s n eed t o k now or kin g p rof essionals, r egar dless of ex pert ise. t he t opology of t h eir own ar ea. A r out er can be con figur ed as a Lev el 1/ 2 r out er ; in w hich case, Reader it k now s w bot ill hobt t he ainlocal a g reat ar eaerr out un der es an st an d ding t h e int oferLAN areaand rouWAN t es. Th n et e wLev or keling, 1/ 2pIar nttegr icu lar at ed ly tIhS-e I S rhar outdw er ar leaks e, prtot heocols, Lev eland 1 I Pser infvorm icesatinv ionolvint edo. Level Fu ndam 2 and ent al can t ech benology sum m ar infizored mat duion rin gist pr h isovprided ocess. on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Depend in gcon oncept t h e net w or k desig t h e rclosest Levand el 2 ad rou m igr ht notr ces be ftor h e fu opt im um t raf. fic t o en su re comp r eh en sionn, and et en t ion, ditt er ional esou rt her st udy pat , bu et tis h ealso Lev ext el 1end r out does not ow nt his, b ecause it cant s,see r out es. For Covherag edern ot only t okn new et wor k ing concep butonly alsot he t o Level old er , 1legacy exam ple, in ovid Figur - 3, Lev elic 1pict Rout chooses Rout it s en closest Level er . I f syst em s, pr in eg 48 am or teh reealist ur eerof3B t he real- w or ld neret3A w oras k ing vir onm ent s2inr out w hich tpr heof tessionals raf fic w eroper e dest f or Ar ea gu 2, idRout er 3f or Aw ould hav e syst t o for ar d for it m viaance a long patease h t han if at ined e. Tools and elines opt im izing emw per w illerincr Rou t erct3B it ially t h e help t r affing ic t ow t h e ot ele2inr tout er, Rout er -3eff C.icient pr odu iv it in y an d imchose pr ov et oeffsend iciency, t heard r eader mher akeLev mor elligent , cost decisions for t h eir net w ork s. To ad dr ess t his issu e, an enh ancem ent t o I nt eg rat ed I S- I S allows a Lev el 2 rou t er t o leak select ed r out es int o t h e Level 1 ar ea. The Lev el 1 r out er s can t h en m ak e a m or e int elligent or opt im al f or w ard in g decision. How ever , t h e increase in rou t ing infor m at ion is a t r ade- of f against t he scalabilit y of t he origin al I S- I S r out ing ar chit ect u re. I S- I S r out er s discov er t heir n eigh bor s aut om at ically by sending ou t hello p ack et s. On point - t o-

point link s, t hey f orm a dir ect peerin g an d f lood t heir r out ing inf orm at ion in lin k- st at e p ack et s ( LSPs) . Th e inf orm at ion in t he LSP is used t o bu ild t h e link - st at e dat abase ( LSDB) fr om w hich a shor t est - pat h t r ee is con st r uct ed and also is used t o pop ulat e t h e for w ar ding t able. On br oadcast n et wor k s, t he hello packet s ar e sent on w ell- kn ow n m u lt icast MAC ad dr esses. A Desig nat ed I n t erm ediat e Sy st em ( DI S) is elect ed and does t h e floodin g of LSPs on behalf of t he ot her r out er s on t hat seg m en t . •

Table of Content s

•

I ndex

Packet I nt e rn et w orTypes k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

As discussed , I S- I S r out ers send hello p ack et s f or aut om at ic neigh bor d iscover y of bot h Lev el 1and Lev el 2- capab le rou t er s. Pub lish er: Cisco Press

Pub bert he 1 1, f2ields 003 in t h e I S- I S Lev el 1 an d Lev el 2 hello pack et . Figur e Dat 48 e: - 4Sep shtem ows I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 4 8 -4 . I S- I S Lev e l 1 a nd Le ve l 2 He ll o Pack et Fie lds The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Here are d escr ip t ions of t h e pack et fields: I nt r ad om a i n R out in g P rot ocol D iscri m i na t or— 8 b it s. The net w or k lay er id en t ifier for

t he I S- I S pr ot ocol ( 0x 83 ) . Le ng t h I n dica t or— 8 b it s. The header leng t h in by t es. V e rsion/ P rot ocol I D Ex t e nsion— 8 b it s. Set t o 1. I D Len gt h— 8 b it s. The lengt h of t h e Sour ce I D f ield. A v alue of 0 m ean s a d ef ault I D Leng t h field size of 6 by t es. •

Table of Content s

I ndex Re ser ve d/ Ty pe — 3 b it s/ 5 b it s. The f ir st 3 b it s are reser v ed. Th e last 5 bit s def in e t he t yp e I nt e rn of et wPDU. or k ingHello Te chnologie ndbook , Four pack ets sH ahav e t he PD th U Edit t yp eionv alu es sh ow n in Table 4 8- 1. •

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Tab le 4 8 - 1 . PD U Ty pe Va lu es f or H el lo Pa ck e t s

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Ty pe

V a lue

15

Lev el 1 LAN I S- I S h ello

16

Lev el 2 LAN I S- I S h ello

The net w-ork r efIerence p rov ides cover age of 17 u pdat ed edit ion of t he b est - selling all- in- one Point t o- ing point S- I S hello essent ial an d cu t t ing- edg e t ech nologies. V e rsion— 8 bov it s. t v ersion is essen 1. Con cise er The v iewcur s ofr en t echn olog ies t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Ma x im um Are a Add re sse s— 8 b it s. The nu m ber of ar ea addr esses allow ed w it hin t his ar ea, fr om New 1 t o 25 4. Aervalue of 0 cov im plies eat ant addrt opics esses.like VoI P and EAP chapt s include erag et hr ofee imar por Re serCov ve d/ Cire cu Type 6 b itt echn s/ 2 bologies it s. Thelikcircuit t y pen et is wor ident if iedand accord in g t he v alues show n erag of itcut t ing — edge e opt ical k ing st or age in Table 4 8- 2. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Tab 2 s, . Cir pe ologies, Va lu es H el lo Pack e t s ' s net w ork ing t echnologies. Mast er le t he4t8er-m concui cep tts, Ty t echn an fdor devices used in t oday indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, V a lue D e scri pt i on and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net ise. v ed 00w or kin g p rof essionals, r egar dless of ex pert Reser 01 el and 1 Reader s w ill obt ain a g reat er un der st an ding ofLev LAN WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on 10 Lev el 2 a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o11en su re con cept comp r eh en sion and r et en t ion, dit 2ional r esou r ces f or fu rt her st udy . Levand el 1 ad and Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr oduSou ct iv it y an imThe pr ovlengt e eff hiciency, help in ingt he t heI Dr eader e in t elligent , er cost effsticient rce I Dd — cont ained Lengt m h ake f ield.mor The sour ce r out 's -sy em I D. decisions for t h eir net w ork s. H old ing Ti m e r— 16 bit s. P DU Len gt h— 16 bit s. The leng t h in clu des t he PD U header and t h e var iable- len gt h fields. Re ser ve d/ P ri orit y— 1 b it / 7 bit s. Det erm ine t he pr ior it y w hen elect in g t he DI S on

br oadcast n et wor k s. LA N I D — Syst em I D of t he DI S plus 1 ext r a by t e. V a ria bl e- Le ngt h Fie ld s— TLVs ar e included her e.

• •

Table of Content s

NO TE I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

The Poin t - tInc. o Poin t By Cisco Systems,

I S- I S h ello PD U is ver y similar t o t he LAN h ello. The oct et con t aining t he Prior it y f ield is om it t ed because t her e is no need t o elect a DI S. Th e LAN I D field is r ep laced by a sin gle oct et local circuit I D.

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

I S- I S Pages: r out er11 s 28 exchan ge r out ing inf or mat ion w it h t heir neighb or s using LSPs. The act u al adv ert ised net w ork addr esses ar e st ored as Ty pe Len gt h Values ( TLVs) foun d at t h e en d of t he LSP. Figur e 48 - 5 sh ows t he f ields in t h is packet . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r e 4 8 -5 . I S- I S Lev e l 1 a nd Le ve l 2 LSP Packe t Fi el ds Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Here are d escr ip t ions of t h e pack et fields: I nt r ad om a i n R out in g P rot ocol D iscri m i na t or— 8 b it s. The net w or k lay er id en t ifier for t he I S- I S pr ot ocol ( 0x 83 ) . • •

of Content Le ng t hTable I n dica t or— s8 b it s. The header leng t h in by t es. I ndex

I nt e rn V ete wrsion/ or k ing Te chnologie H a Ex ndbook , Four th Edit P rot ocol sI D t e nsion— 8 b ion it s.

Set t o 1.

By Cisco Systems, Inc.

I D Len gt h— 8 b it s. The lengt h of t h e Sour ce I D f ield. A v alue of 0 m ean s a d ef ault I D Leng t h field size of 6 by t es.

Pub lish er: Cisco Press Pub Dat e: Sep temP ber 1 1,Typ 2 003e— Re ser ve d/ DU

3 b it s/ 5 b it s. The f ir st 3 b it s are reser v ed. Th e last 5 bit s def in e t he I SBN: t yp1-e58of705 PDU. -1 19 -2Hello packet s h ave t he PDU t yp e valu es sh own in Table 4 8- 3. Pages: 11 28

Tab le 4 8 - 3 . He llo Pack e t PD U Ty pe s The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essentV iala lue an d cu t t ing- edg e t ech nologies. D e scri pt i on 18 Lev el 1 lin k st at e PDU Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom 20 Lev el 2 lin k st at e PDU nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP V e rsion— 8 b it s. The cur r en t v ersion is 1. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Ma x im um Are a Add re sse s— 8 b it s. The nu m ber of ar ea addr esses allow ed w it hin t his Aut h ored st vems, leader net w or king f or t he I n t er n et . ar ea, fr omby1 Cisco t o 254Sy . A alue wofor0ldw imide plies t hr eeinarea addr esses. I n t ernPetDU w orLen k in gt g Tech nologies Hand book t h Ed a com pr ehensive hat h— 16 bit s. The leng t h ,inFour clu des t heit ion PD ,Uisheader and t h e var refer iable-ence len gtt h fields. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Re m ai niMast ng Lif er et t he imte— er m16 s, con bit s. cep The t s, ttim echn e inologies, secondan s befor d devices e t he used LSP ex inpir t oday es. ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . LSP The an I D dLengt h ed pluchapt s 16 bit Thsecur e I D it isyf,orm fr om h e Sy stw em D g, plus t he Com plet e IwDit— h new u pdat er ss.on st ored age, opttical net or kI in scalabilit y, pseudon ode I D and LSP fr agm ent at ion num b er . and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Che ck sum — 32 bit s. Calculat ed fr om t h e LSP I D t o t he end of t he PDU. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e P ar it iocols, on) — and 1 b itser . Avvices alueinv ofolv 1 ind es t h at ig nology inat or sup por t s ion par tisit ion air .on har dwPar( e, prt ot ed . icat Fu ndam entt hale tor ech inf or mat pr ovr ep ided a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions ATT ( At cept t a ch comp ed ) —r eh 4 ben it s. I n dicat t het ion, t y peand of rad oudit t ing metr esou r ic: def ault , exp en se, t o en su re con sion and res et en ional r ces f or, delay fu rt her st udy . or err or . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich L bi t — 1 b it . A v alue of 1 ind icat es t h at t h e or ig inat or is ov erload ed and shou ld n ot be pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease considered in sh ort est - pat h t r ee ( SPT) calculat ions. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for e— t h eir s. es t he I S Lev el, as per Table 4 8- 4. I S Typ 2 bnet it s.w ork I n dicat

Tab le 4 8 - 4 . I S Ty pe

• •

V a lue

D e scri pt i on

01

Lev el 1

11

Lev el 2

Table of Content s

Ty pe Le ng t h Fie l ds— t rip le leng t h valu e ( TLV) are in clu ded h er e. I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

TLVS

Pub lish er: Cisco Press

The v ar iable- len gt h field at t he en d of t h e hello PDU an d t he Ty pe Len gt h field at t h e en d of lin k Dat e: Sep tem ber 1 1, 2 003 st atPub e PDUs cont ain TLVs. Th is is w here t he act ual net w ork ad dr esses ar e cont ained in an LSP. I 58 705 -1 19 -2 The g enSBN: er ic1-f ields for a TLV are sh own in Table 4 8- 5. Pages: 11 28

Tab le 4 8 - 5 . TLV Fie ld For m a t The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent Fie ld ial an d cu t t ing- edg e t ech nologies. Le ng t h i n Oct et s Ty pe 1 Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Lengnov t h ice t o ex pert . 1 Value As def in ed b y Lengt h New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Or iginally , t en TLV codes w er e defined for car r y in g in for m at ion, such as CLNS add resses an d Aut oredaut byhent Cisco Sy st ems, w at or ion. ldw ide leader in net w or king f or t he I n t er n et . neighb orhand icat ion in for m I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . TE Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . NO Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, RFC 119 t h5, is Ibook n t egrat is aedcom I S- Iplet S, int e an rodduced u p- t oa d new at e set r ef er ofence TLV tcod o t he es t o opsup ics por t hatt Iare PV4essen t ial t o all net w or add kin resses. g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on IaSb Ir S oad is ext r ang enesible of intbegr y defin al syinstgem n ew s and TLVs. serv This ices,is in how cludI ing S- I Sdet sup ailed por tdescr s newiptf eat ion ur s, es revsu iew ch quest as I Pvions 6 t o en or MPLS su reTE. conTable cept comp 4 8- 6 rlist eh sensom sione and of t he r etcom en t ion, m onand TLVs adim ditplement ional r esou ed in r ces I OS. f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Tab le 4 8 - 6 . Com m on TLVs

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V a lue

D e scri pt i on

1

Ar ea add resses

2

I I S neighb or s

8

Padd in g

10

Table of Content s

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I ndex

Aut h en t icat ion TE I I S neighb ors

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

12 8

I P int er ior r each abilit y

12 9

Pr ot ocols su ppor t ed

By Cisco Systems, Inc.

13 Pub 0 lish er:

Cisco Press

I P ex t er ior ad dr ess

Pub Dat e: Sep tem ber 1 1, 2 003

13 2 13 4

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

I P int er ior add ress TE r out er I D

13 5

TE I P r each abilit y

13 7

Dy nam ic host nam e

10 and 1 33 Aut hnet en tw icat The u pdat ed edit ion of t he b est - selling all- in- one orkion ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iewin s ofIS-IS t echn olog ies essen t ial t o n et wor k ing Metrics Defined

pr ofession als at all lev els, f rom

nov ice t o ex pert . Four m et r ics ar e d ef ined in I S- I S: cost , delay, ex pense, and er ror . Of t hese, on ly cost is New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP m andat ory an d is used in t he Cisco I OS im plem ent at ion . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age The d ef ault cost is fix ed at 10 . The m ax imu m int er faces cost is 63 . The m ax imu m pat h cost of 10 23 lim it s t he size of t he n et w or k an d p laces r est r ict ions on r out ing design. I OS supp or t s w id e Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . m et rics, a 24 - bit m et r ic field, t o add ress t his issue. How ev er , you m ust en su r e t hat all I S- I S er et s supp his f eat ur e, orHand pr oblem w ill occur hen t he SPT.refer ence t hat Ir nout t ern w or kort in g tTech nologies book s, Four t h Ed itwion , iscalculat a com ing pr ehensive enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IS-IS LSP Processing As each r out er r eceiv es LSPs, it ad ds t h em t o it s LSDB if t h e LSP' s seq uence num b er is higher t han t h e one alr eady st or ed . The LSDB d escr ib es all t he n et wor k s, m et r ics, and r eachab ilit y inf orm at ion for each r out er t o build it s shor t est - p at h t r ee u sin g t h e Dij kst r a algor it hm . I t t hen •const r uct s it sTable s le fr om t h is. f orwofarContent din g t ab •

I ndex

IWhen nt e rn ett w k ingt er Te chnologie H a ndbook th Edit heor rou receiv ess an LSP, it, Four floods it tion o all it s neighb ors ex cep t t h e neighb or it w as rByeceived fr om . I SI S uses a reliable flood in g mechanism an d som e add it ional PDU t yp es: Cisco Systems, Inc. Com plet e Sequence Nu mb er PDU ( CSNP) and Par t ial Sequence Num ber PD U ( PSNP) . Lev el 1 and Lev el 2 CSNP and PSNP PDU t y pes exist . Pub lish er: Cisco Press

Dat e:ing Seprtem 1, 2 003 ThePub r eceiv outber er 1sen ds a PSNP ( cont ainin g t h e LSP sequ en ce num ber ) b ack t o t h e neighb or I SBN: 158 705 -1 19 ackn ow ledg ing receip -2 t of t h e LSP. W hen t he sour ce rou t er r eceiv es t he ack now ledgm ent , it st ops sen ding Pages: t he11upd 28 at e LSP on t hat in t er f ace, b ut con t inues t o do so on ot her int er faces w here it has not y et r eceived a PSNP.

On br oadcast m edia, n o PSNPs ar e sent as ack now ledgm ent s. Th e r out er s w ait t o receiv e a CSNP t hat cont ains a list of LSPs and t heir seq uence num b er . Th e receiv ing r out er s can t hen d et er m ine if t hey m issed any LSPs or if any ar e out of dat e and t hen requ est t hem v ia a PSNP. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

IS-IS DIS Election

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . On br oadcast m edia, on e I S- I S r out er becom es t he DI S an d for m s t he p seud onode. Th is elect ion is based on t h e pr ior it y con figu r ed on each r out er 's in t er f ace. Th e pseu donod e r ep resen t s a LAN New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP seg m en t , and all r out er s ( non pseu donod es) for m an adj acen cy w it h it . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Not e t h at DI S elect ion is p reem pt iv e. Adding a rou t er w it h a high er pr ior it y causes it t o displace t he cuAut rr ent DI Sby anCisco d b ecom e ems, t he DI selfide , creat ing in a net neww pseudon ode. h ored Sy st wS oritldw leader or king f or t he I n t er n et . Ev 3w seconds, t h e nologies DI S sends ou tbook CSNPs listting allit ion t h e, LSPs. Anpr y ehensive rou t er canrefer r equest issin g or I n tery ern et or k in g Tech Hand , Four h Ed is a com ence m t hat m or er ecent LSPs by sen ding a PSNP. Similar ly, it can updat e t he p seud onode by sen ding or eenables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w orkming rt echnologies. ecent or m issing LSPs t o t h e DI S. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t hBlack is book Holes is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Avoiding with IS-IS net w or kin g p rof essionals, r egar dless of ex pert ise. The ov er load b it allow s a r out er t h at is r u nning low on cr it ical r esour ces t o indicat e t o it s Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e neighb or s t hat it shou ld n o long er b e used as a pat h f or t r ansit t raf fic. How ever , t he rou t er st ill har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on par t icipat es in t he I S- I S r out er h ier ar ch y. This ov er load bit is also used in RFC 3 277 , a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions I n t erm ediat e Sy st em –t o– I nt er m ed iat e Syst em ( I S- I S) Tran sient Blackh ole Av oidance Feat ur e. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag is BGP also Iext endwed n otwh only new work kring s, nor butmally also tin o old , legacy I n an I S-eI S/ P net or k, en at ocor e nnetetwor out concep er t hat tis t heert raf fic p at h is syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent in dw thich r eb oot ed, it mig ht con ver ge I S- I S m or e quick ly t han BGP. I n t his case, ot her r out er s ssen raf fic pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr t o wh er e t he BGP next hop f or t hat t r aff ic can b e reached via I S- I S. W hen t hat t raf fic arease r ives at pr odur ecent ct iv it yly an d im pr e eff iciency, help t he r eader e inent t elligent t hat r eboot edovrou t er, t he r out er ing d oes not h ave m a ake f orwmor ar ding r y f or, tcost hat -teff r afficient ic' s decisions for t h eir net w ork s. dest inat ion addr ess, becau se BGP has not finished con ver ging y et . The t r af fic is d rop ped in t o a black hole. Wit h RFC 327 7, t h e r eb oot in g rou t er set s t he ov er load bit in it s LSPs un t il BGP is con ver ged. Th is r out er st ill can b e r eached v ia I S- I S by ot her r out ers, b ut is not used f or t r ansit t r af fic. When BGP is fu lly u p, it clear s t he over load b it and is u sed in t h e t r aff ic pat h t o reach t he BGP nex t

hop s.

Route Leaking As m ent ioned pr ev iously , carefu l r out e leak ing fr om Lev el 2 t o Lev el 1 can allow Lev el 1 r out er s t o ch oose a m or e opt im al pat h w h en an ar ea has m or e t han on e Level 2 r out er . Nor m ally , t h ey •choose t he closest Table of Content . Anot hers ap plicat ion of r out e leak in g is t o sup por t MPLS VPNs. MPLS VPNs use •m BGP t o exchan I ndexge r out in g in for m at ion b et ween PE r out er s an d m ust see t h e BGP next hop ( a I/ nt w or k ingess) Te chnologie a ndbook Four Editfion 32e rn h et ost addr in t heirs How n r ou t, in g tth able or t he r out e t o b e valid. By Cisco Systems, Inc. Pub lishTraffic er: Cisco Press MPLS Engineering Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58s705 -1 19 MPLS TE allow t raf fic-2t o be for w ard ed b ased on decisions ot h er t han t he n ex t hop for an I P pr efix .Pages: The MPLS 11 28 rou t er can set up t u nnels based on t he av ailab ilit y of r esour ces in t he net w ork . These t un nels can h ave an ex plicit or dy nam ic Lab el- Sw it ched Pat h. Th e set u p of a dy nam ic LSP is gov ern ed b y t he av ailable r esou rces along t he p at h, su ch as av ailable ban dw idt h, lin k aff init y , and MPLS- sp ecific lin k cost . To obt ain t h is addit ional " available r esour ce" in for m at ion about t he net w or k, new TLVs hav e been d ef ined—TLV 22 and TLV 135 . These descr ibe n eig hbor s an d I P net ks in e same 2, all128in, and , t hese new TLVs also supp Thewuor pdat edt hedit ion ofway t he tbhat est -TLVs selling one 13 net0 wdo. orkHow ing rever ef erence p rov ides cover age of ort subTLVs w it hin t he TLV t o descr ibe t h e add it ion al char act er ist ics of t hat n eig hbor or pr efix , such essent ial an d cu t t ing- edg e t ech nologies. as av ailable ban dw idt h.

Refer Con t o tcise he " For e sI nf at ion" ion f ort ial f urt ot her orm at ion on t hese ot her I S- IfS ov erMor v iew oform t echn olog sect ies essen n et inf wor k ing pr ofession alsand at all lev els, rom feat u res an d d ev elopm en t s. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IDRP I DRP is an OSI pr ot ocol t h at specifies how r ou t er s com m unicat e w it h r out ers in d if fer en t dom ains. I DRP is designed t o op er at e seam lessly wit h CLNP, ES- I S, an d I S- I S. I DRP is based on BGP, an int er dom ain r out ing pr ot ocol t h at or iginat ed in t he I P com m unit y . I DRP feat u res includ e •t he follow in g:Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Sup por t f or CLNP qu alit y of ser vice ( QoS)

By Cisco Systems, Inc.

Loop sup pr ession b y k eeping t r ack of all r out ing d omains ( RDs) t rav er sed by a rou t e Pub lish er: Cisco Press Pub Redu Dat e:ctSep iontem ofber r out 1 1,e2 003 in for m at ion

an d p r ocessin g b y using confeder at ions, t h e com p ression of RD pat1-h58inf or-1mat I SBN: 705 19 -2ion , and ot h er m eans Pages: 11 28

Reliabilit y by u sing a built - in r eliable t r an sp ort Secu rit y by using cr yp t ogr aphic sign at ur es on a per - pack et basis Rou t e ser v er s The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

IDRP Terminology Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom I DRP nov int rice oduces er. al env ir onm ent - sp ecific t er m s, in clu ding bor der int er m ed iat e syst em t o exsev pert ( BI S) , r out ing d omain ( RD ) , r out ing dom ain ident if ier ( RDI ) , r out ing inf or mat ion base ( RI B) , Newedchapt er s include cov erag e of im por t ant t opics like VoI P and EAP and conf er at ion. erag of cut edge t echn ologies likrou e opt icaland, n et wor k ing and age An RD is a gr oup ABI S Cov is an I S et hat part ing t icipat es in int er dom ain t ing as such, u sesstIor DRP. of ESs an d I Ss t hat operat e und er t he sam e set of adm inist rat iv e r ules and t h at shar e a com m on Autplan h ored Cisco stiq ems, w orident ldw ide king or tabase he I n t er n et .b y I DRP t hat is r out ing . AnbyRDI is aSyun ue RD if ierleader . An RIinB net is awror out ing fdat used bu ilt by each BI S fr om inf or mat ion r eceiv ed f rom t he RD an d ot h er BI Ss. An RI B con t ains t h e set Iof n trern or k in g Tech nologies Hand book BI , Four Ed ed it ion , is a is com ence hats t o outet esw chosen f or use b y a par t icular S. At hconf er at ion a pr gr ehensive oup of RDrefer s t hat apptear enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ing RD s out side t h e confeder at ion as a single RD. Th e con feder at ion's t opology is in visible t oork RDs tout echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing side t he conf ed er at ion. Conf ed er at ions mu st be nest ed w it hin one anot her. They help r educe indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . net w or k t r aff ic by act ing as int er net w or k fir ew alls. Figur e 48 - 6 illust r at es t he relat ionship Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, bet w een I DRP ent it ies. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Figu r e 4 8 -6 . D om a in s Com m u ni ca t e Vi a BI Ss har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

•

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

IDRP Routing The u pdatrou ed t e edit of t he b est selling all-einnet w orkbing r effeder erence p rov ides age of An I DRP is ion a sequence of -RDI s, som ofone w hich can e con at ions. Eachcover BI S is essent ial an d cu t t ingedg e t ech nologies. conf ig ur ed t o k now t h e RD and t he con federat ion s t o wh ich it belon gs. I t lear ns ab out ot her BI Ss, RDs, an d conf ederat ion s t hr oug h in for m at ion ex ch anges w it h each neigh bor . As w it h dist ance- vect or r out in g, r out es t o a p art icular dest in at ion accum ulat e ou t w ard f rom t he Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom dest inat ion. Only r out es t h at sat isfy a BI S' s local policies an d t hat hav e been select ed for u se ar e nov ice t o ex pert . passed on t o ot her BI Ss. Rout e recalcu lat ion is p art ial and occur s w h en one of t hr ee ev ent s occu r New s: anchapt in cr em t al r outcov in gerag u pdat e wit n ew t es islike receiv a BI S neighb or goes d own , er seninclude e of im hpor t antrou t opics VoIed, P and EAP or a BI S neighb or comes u p. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary I S- I S is based on w or k or iginally don e at D igit al Eq uipm ent Cor por at ion ( Digit al) . OSI rou t ing pr ot ocols ar e sum m arized in sever al I nt er nat ional Or ganizat ion for St andar dizat ion ( I SO) docum ent s. Th e I SO d ev elop ed a com p let e suit e of r ou t in g pr ot ocols for u se in t h e Open Syst em •I nt er con nect ion Table( OSI of Content ) pr otsocol suit e. •

I ndex

IThe nt e rn or kof ingOSI Te chnologie H agndbook , Fourethspecif Edit ion wetorwld net w or ks in uses som ic t er minolog y, su ch as end sy st em ( ES) , w hich rByefCisco ers t o any nonr out in g n et wor k n odes, and int er mediat e sy st em ( I S) , w hich r efer s t o a r out er . Systems, Inc.

OSI r ou t in g begins w hen t he ESs discover t h e near est I S. When an ES w ant s t o send a p ack et t o lish er: Cisco Press anotPub h er ES, it send s t he packet t o one of t he I Ss on it s dir ect ly at t ach ed n et w or k . Pub Dat e: Sep tem ber 1 1, 2 003

En d SyIst SBN: em– 1- 58 t o–I 705nt -1er 19m -2 ed iat e Syst em ( ES- I S) is an OSI pr ot ocol t hat d ef ines how en d sy st em s ( host s)Pages: and 11 in28 t erm ediat e sy st em s ( r out er s) learn ab out each ot her . I nt er mediat e sy st em – t o–int er m ed iat e sy st em ( I S- I S) has been ext en ded t o also supp ort r out ing of classless I P net w ork s. This ex t ended ver sion is k now n as I nt egr at ed I S- I S. I nt er dom ain Rout ing Pr ot ocol ( I DRP) is an OSI p rot ocol t hat sp ecifies how rou t ers com m unicat e The pdat ed in edit of tt he b est -s. selling all- in- one net w ork ing r ef erence p rov ides cover age of w it h urou t ers difion fer en d omain essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What t w o t yp es of m essag es are sent bet w een syst em s in an ES- I S?

2:

I ndex is t h e diff er ence bet w een a Level 1 r out er an d a Lev el 2 I S- I S rou t er ? What

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : Descr By Cisco Systems, Inc.ibe 4:

h ow I S- I S r out er s comm u nicat e w it h each ot her on br oadcast n et w or k s.

What w as t h e orig in al pu r pose of t he ov erload bit ?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

What is a TLV?

I SBN: 1- 58 705 -1 19 -2 Pages: 28 6 : 11How

is t h e I S- I S m et ric f igur ed on each lin k?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • I SO/ I EC 1 058 9: 20 02 St and ard : I nt er m ed iat e Syst em –t o–I n t er m ediat e Sy st em in t r a- dom ain r out ing inf or mat ion exch ange p rot ocol for u se in conj unct ion w it h t he pr ot ocol f or pr ov iding t he •connect ionlessTable of Content m ode n et w sor k serv ice ( I SO 8 473 ) , w w w .iso. or g. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

• Whit e pap er : " I nt er m ed iat e Syst em –t o–I nt er m ed iat e Sy st em ( I S- I S) TLVs," Cisco Sy st ems, By Cisco Systems, Inc. 20 02, w w w .cisco. com . Pub lish er: Cisco Press

• Whit e pap ertem : " I ber nt r 1odu ion t o I nt erm ediat e Sy st em – t o–I nt er mediat e Syst em Pr ot ocol, " Cisco Pub Dat e: Sep 1, 2ct 003 Sy st emI SBN: s, 201-02, w -1 w 19 w .cisco. com . 58 705 -2 Pages: 11 28

• RFC 1 195 , Use of OSI I S- I S for Rout ing in TCP/ I P an d Du al Env ir on m ent s , Callon , R. ( D igit al Eq uipm ent Cor por at ion) , D ecemb er 199 0, w w w .iet f .or g. •The RFC 3 277 n t erm e Sy st em –t o– I nt erinm ed iatnet e Syst em S) Tranpsient Blackh oleage of u pdat ed, Iedit ionediat of t he b est - selling allone w ork ing( I rSefIerence rov ides cover Av oidan ce, McPh er son, D . ( TCB) , Ap r il 200 2, w w w .iet f .or g. essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 49. Routing Information Protocol Obj e ct i ve s • •

Table of Content s

Nam e RI P's st ab ilit y feat ur es. I ndex

I nt e rn Ex et wplain or k ingt he Te chnologie s Hce a ndbook , Four thing Editm ion sign if ican of RI P's t im ech anisms. By Cisco Systems, Inc.

Descr ibe t he dif fer en ces b et w een RI P and RI P 2. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background The Rout ing I nf orm at ion Pr ot ocol, or RI P, as it is m or e com m only called , is one of t he m ost endu rin g of all r ou t ing pr ot ocols. RI P is also one of t he m or e easily conf used pr ot ocols because a v ariet y of RI P- lik e r out ing pr ot ocols pr olifer at ed , som e of w hich ev en used t he sam e nam e! RI P •and t h e m yr iad Table s ocols w er e based on t he sam e set of algor it hm s t hat u se dist ance RIofP-Content lik e p rot •v ect or s t o m at I ndex hemat ically com par e r out es t o id en t ify t h e best pat h t o any g iven dest in at ion Iadd nt e rn et w or k ing Tealgor chnologie a ndbook , Four th Edit ion ic research t hat dat es back t o 19 57. ress. These it hmssHemer ged fr om academ By Cisco Systems, Inc.

Today ' s open st an dar d ver sion of RI P, som et im es r efer red t o as I P RI P, is f orm ally def in ed in t w o docum ent s: Request For Com m ent s ( RFC) 10 58 and I nt er net St an dar d ( STD) 5 6. As I P- b ased Pub lish er: Cisco Press net w or ks becam e b ot h mor e n um er ous and gr eat er in size, it b ecam e app arent t o t he I nt er net Pub Dat e: Sep tem ber 1 1, 2 003 En gineer ing Task For ce ( I ETF) t hat RI P n eeded t o b e up dat ed. Conseq uent ly , t he I ETF released I SBN: 58 705 -1 19 -2 3, w h ich w as t hen super ceded in Nov em ber 199 4 by RFC 172 3, w h ich RFC 138 8 in1-Jan uar y 199 Pages:RI11 descr ibes P28 2 ( t he secon d v er sion of RI P) . Th ese RFCs descr ibed an ex t en sion of RI P' s capabilit ies but did not at t em pt t o obsolet e t he pr ev ious v ersion of RI P. RI P 2 enab led RI P m essages t o car r y m or e infor m at ion, wh ich per m it t ed t h e use of a sim ple au t hent icat ion m ech anism t o secu re t able up dat es. Mor e im por t ant ly , RI P 2 sup por t ed sub net m ask s, a cr it ical feat u re t hat was not available in RI P. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of This chap t erdsu basic cap abilit ies an d f eat ur es associat ed w it h RI P. Top ics includ e essent ial an cumt tmar ing-izes edg et he t ech nologies. t he rou t ing upd at e pr ocess, RI P rou t ing m et r ics, r out ing st abilit y, and r out ing t im er s. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Routing Updates RI P send s r out ing- updat e m essages at r egu lar in t erv als and w hen t he n et wor k t opology chang es. Wh en a r out er r eceives a rou t ing upd at e t hat includes chan ges t o an ent r y , it updat es it s r out in g t ab le t o r eflect t h e new r out e. Th e m et r ic v alue f or t he p at h is increased b y 1, an d t he •sen der is indicat Tableed of as Content t he ns ex t hop. RI P r out er s m aint ain only t he best r out e ( t he r out e w it h t he •low est m et r icI ndex v alue) t o a d est inat ion . Aft er u pdat in g it s rou t ing t able, t he rou t er im m ediat ely Ibegins nt e rn et w k ing Tet in chnologie sH ndbook , Four th Edit t ror ansmit g r ou t in g aupd at es t o inf or mionot her n et w or k r out er s of t he ch ange. These up Cisco dat esSystems, ar e senInc. t ind ep en dent ly of t h e regu larly scheduled upd at es t hat RI P r out er s send. By Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

RIP Routing Metric RI P uses a sin gle r out ing m et r ic ( hop count ) t o measur e t he dist ance bet w een t he sou rce an d a dest inat ion net w or k. Each h op in a pat h fr om sour ce t o dest in at ion is assigned a h op coun t v alue, w hich is t yp ically 1. When a r out er r eceives a r out ing up dat e t h at cont ain s a n ew or •chang ed destTable of Content s k ent r y, t he r out er ad ds 1 t o t he m et r ic value in dicat ed in t he updat e inat ion net w or •and ent er s t he I ndex n et wor k in t he rou t ing t able. The I P addr ess of t he sender is u sed as t he next Ihop nt e rn . et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

RIP Stability Features RI P pr ev ent s r out in g loop s fr om cont in uing indef in it ely b y imp lem ent ing a lim it on t he nu mb er of hop s allowed in a pat h f rom t he sour ce t o a dest inat ion. The m ax im u m nu mb er of hops in a p at h is 15 . I f a r out er r eceiv es a r out ing up dat e t hat cont ain s a n ew or chang ed ent r y , and if •incr easing t he Table Content metofr ic v alues by 1 causes t he met r ic t o be inf in it y ( t hat is, 16 ) , t he n et wor k •dest inat ion isI ndex consid er ed unr each able. The d ow nsid e of t his st ab ilit y f eat ur e is t hat it lim it s t he Im ntaxim e rn etum w or kdiam ing Teet chnologie a ndbook Edittion er of a sRIHP n et w or, Four k t othless h an 16 hops. By Cisco Systems, Inc.

RI P in clu des a n um ber of ot her st abilit y f eat u r es t hat ar e com m on t o m any r out in g pr ot ocols. These feat ur es ar e designed t o p rov ide st ab ilit y d espit e pot ent ially r apid ch anges in a net w or k 's Pub lish er: Cisco Press t opolog y. For ex am ple, RI P im plem en t s t he sp lit hor izon and holddow n m ech anisms t o pr ev en t Pub Dat e: Sep tem ber 1 1, 2 003 incor rect r out in g in for m at ion fr om being pr opag at ed. I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

RIP Timers RI P uses n um erou s t im er s t o r eg ulat e it s p er for m ance. These include a r out ing - upd at e t im er , a r out e- t im eou t t im er , and a r out e- f lush t im er . The r ou t ing- u pdat e t im er clock s t h e int er val bet w een per iodic r out ing u pdat es. Gener ally , it is set t o 3 0 seconds, w it h a sm all r and om •am ount of t im Table of ed Content s e add w henev er t he t im er is r eset . This is d one t o help pr ev ent con gest ion , •w hich cou ld rI esu ndexlt f rom all r out ers sim ult an eou sly at t em pt in g t o up dat e t h eir neig hbor s. Each Ir nt e rn et wt or ingen Tetchnologie H a ndbook , Four th Edit out ing abkle ry has as rou t e- t imeout t im erion associat ed w it h it . Wh en t he rou t e- t imeout t im er expCisco ires,Systems, t he rouInc. t e is m ar ked inv alid bu t is r et ained in t h e t able un t il t h e rou t e- flush t im er By exp ires. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Packet Formats The f ollow in g sect ion f ocuses on t h e I P RI P and I P RI P 2 p ack et f or mat s illu st r at ed in Figur es 441 an d 44- 2 . Each illu st r at ion is follow ed by descr ipt ion s of t he f ield s illu st r at ed. •

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RIP Packet Format I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figur e 49 - 1 illust r at es t he I P RI P p ack et f or mat . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Figu r e 4 9 -1 . An I P RI P Packe t Con si st s of Ni ne Fie lds

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The f ollow in g d escr ipt ions sum m ar ize t he I P RI P pack et f orm at fields illust r at ed in Figur e 49 - 1: Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice ex pert . Com m at ond— I n dicat es wh et her t he p ack et is a r eq uest or a respon se. Th e requ est ask s t hat a rou t er send all or par t of it s r out in g t able. The r esp onse can b e an unsolicit ed r eg ular New chapt er s einclude cov erag of uest im por t ant t opicscon liket ain VoIrou P and r out ing up dat or a r eply t o a er eq . Responses t ingEAP t able ent r ies. Mult iple RI P pack et s are used t o con vey inf or m at ion f r om larg e r out ing t ables. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age V e rsion num be r— Specif ies t h e RI P v er sion used. Th is field can sig nal d if fer ent p ot ent ially Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . incom pat ible v ersions. I n t ernZe et w or k in g Tech Hand book , Four t h Ed1it058 ion ,RIisP;a itcom pr ehensive refert o ence ro— This fieldnologies is not act u ally used by RFC w as add ed solely pr ovt hat ide enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net back w ard com pat ibilit y w it h pr est an dar d var iet ies of RI P. I t s nam e comes f r om it w s ork ing t echnologies. er t he er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing defau lt edMast v alue: zerto. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new u pdat secur or age, w orRI k in Ad dre ssfa m ian ly dide nt i fied er chapt ( AFI )er—s on Specif iesittyh,estadd ress opt famical ily net used. P g, is scalabilit desig ned y,t o and speed, h is inbook is m a at com an d ualp-dif t o-fer d at erocols. ence t oEach t he ent t oprics t hatanare carr y rtout g in for ionplet foresever enet rpefrot y has adessen dr ess-t ial famt oilyall net w or kin gif ier p roft oessionals, exr ess pertbeing ise. specif ied . The AFI f or I P is 2 . ident indicat e trhegar e t y dless pe of of add Reader w illss— obt ain a g reat ding Ads dre Specif ies ter h e un I Pder addstran ess f or of t heLAN ent and ry . WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad e of int egr sy stm em s and serv clud det descr ipt ion s, rev iewin quest Me rt ang r ic— I n dicat esalhow any in t er n etices, w or kinhop s ing ( r out erailed s) hav e been t r aver sed t he t rions ip t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . t o t he d est inat ion. This v alue is bet w een 1 and 1 5 f or a valid rou t e, or 16 f or an Cov erag e is also ext end un reachable r ou t e.ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

NO TE Up t o 25 occur rences of t he AFI , Ad dr ess, and Met r ic fields ar e p er m it t ed in a sing le I P RI P packet . ( Up t o 2 5 dest in at ion s can be list ed in a single RI P pack et . )

RIP 2 Packet Format The RI P 2 specif icat ion ( descr ibed in RFC 17 23) allow s m ore in for m at ion t o be in clu ded in RI P pack et s and pr ov id es a simp le aut h en t icat ion m ech anism t hat is not su ppor t ed by RI P. Figur e 49 - 2 sh ows t he I P RI P 2 packet for m at . •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 4 9 -2 . An I P RI P 2 Packe t Con si st s of Fi el ds Sim il ar t o Th ose of a n I P RI P Packe t Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The f ollow in g d escr ipt ions sum m ar ize t he I P RI P 2 pack et for m at field s illu st rat ed in Figur e 49 - 2: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Com m a nd— I n dicat es wh et her t he p ack et is a r eq uest or a respon se. Th e requ est ask s t hat a rou t er send all or a par t of it s r out ing t able. Th e respon se can be an u nsolicit ed rCon eg ular out u pdat or aolog r eply a r equest ain rouals t ingat t all able r ies. cise rov erinv g iew s of e t echn iest oessen t ial t o. nResponses et wor k ing cont pr ofession levent els, f rom Mu ip let oRIex Ppert pack. et s ar e used t o conv ey in for m at ion f r om lar ge r out ing t ab les. novltice V e rsion— Specif ies t hcov e RIerag P v er sion I n taopics RI P like packVoI et imp lemEAP ent ing any of t he RI P 2 New chapt er s include e of imused. por t ant P and fields or usin g aut hent icat ion, t his v alue is set t o 2. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age U nused — Has a v alue set t o zero. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Ad dre ss- fa m i ly ide nt i fi er ( AFI ) — Specif ies t h e add ress fam ily used. RI Pv 2' s AFI field I n t ernfuetnct w or ions k in gident Techically nologies t o RFC Hand 1 058 book RI, P' Four s AFI t h field, Ed it ion w ,it is h one a com expr cept ehensive ion : I f trefer he AFI ence f ort hat t h e fir st enables entnet r y in w or t he kinmg essag p r ofessionals e is 0x FFFF, t o un t he derst r em and ain an derd of imtplem he enen t ry t cont con em t ains poraut ar yhent int er icat net ion w ork ing t echnologies. inf orm at ion. MastCur er trhe entt ly er,mt he s, con on ly cep aut t s,hent t echn icatologies, ion t y peanisd sim devices ple passw used ord in t. oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Rout — Prov a ed metchapt hod fer orsdist w eenopt intical er nal lear ned b y y, RI P) Com plet e we itthagnew an dides u pdat on ingu securish it ying , stbet or age, netrwout or es k in(g, scalabilit and ext er nal rou t es ( lear ned fr om ot her pr ot ocols) . and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. I P a ddr ess— Specif ies t h e I P add r ess f or t he ent ry . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e mocols, a sk —and Contser ains t heinv sub net ask for ent t healent r y . nology I f t his finf ield is zero, har dwSu ar bne e, prt ot v ices olv ed .mFu ndam t ech or mat ion isnoprsu ovbnet ided on m ask has b een sp al ecified forst and he ent r y .ices, in clud ing det ailed descr ipt ion s, rev iew quest ions a b r oad r ang e of int egr sy st em serv t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Nee xtishop I n end dicat heonly I P ad ess of e nex t hconcep op t o wt s, hich s fold or er t he en t ry sh ould Cov erag also—ext edesntot t odrnew n ett hwor k ing butpacket also t o , legacy be f or w ard ed . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Me t r ic— I n dicat es how m any in t er n et w or k hop s ( r out er s) hav e been t r aver sed in t he t r ip pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient t o t he d est inat ion. This v alue is bet w een 1 and 1 5 f or a valid rou t e, or 16 f or an decisions for t h eir net w ork s. un reachable r ou t e.

NO TE

Up t o 25 occur rences of t he AFI , Ad dr ess, and Met r ic fields ar e p er m it t ed in a sing le I P RI P packet . Th at is, up t o 25 r out ing t ab le en t ries can be list ed in a single RI P pack et . I f t he AFI specif ies an au t hent icat ed messag e, only 24 r out in g t ab le en t r ies can be specif ied . Giv en t h at ind iv idu al t able ent ries ar en 't fr agm ent ed int o mu lt iple pack et s, RI P does not need a mechanism t o r esequence d at agr am s bear in g r ou t ing t able up dat es fr om n eig hbor ing r out er s. •

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary Despit e RI P' s age an d t he em er gence of m or e sophist icat ed r out ing p rot ocols, it is f ar f rom obsolet e. RI P is m at ur e, st able, w idely supp ort ed, and easy t o config ur e. I t s sim plicit y is w ell suit ed f or u se in st ub net w or ks and in sm all aut onom ous sy st em s t h at do not hav e enoug h •r ed und ant pat Table Content s t he ov er h ead s of a m or e sophist icat ed pr ot ocol. hs tof ow ar r ant •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

Nam e RI P's var ious st ab ilit y f eat ur es.

2:

I ndex is t h e pur pose of t h e t im eou t t im er? What

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : What By Cisco Systems, Inc.t w o 4:

cap abilit ies ar e sup por t ed b y RI P 2 bu t n ot RI P?

What is t h e max im um n et wor k d iam et er of a RI P net w or k?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • Sp or t ack , Mark A. I P Rou t ing Fund am ent als. I nd ianapolis: Cisco Pr ess, 1 999 . •

Table of Content s

•• ht t p: / / w w w I.ndex iet f .or g / rf c/ rf c105 8. t x t I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By • htCisco t p: / /Systems, w w w . ietInc. f .or g / rf c/ rf c172 3. t x t Pub lish er: Cisco Press

• ht tPub p: / Dat / w e: ww . cisco.com / cpr ess/ cc/ t d/ cpr ess/ fu nd/ it h 2nd / it 244 4. ht m Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 50. Resource Reservation Protocol • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ex plain t he d iff er ence bet w een RSVP and r out ing pr ot ocols.

By Cisco Systems, Inc.

Nam e t he t hr ee t raf fic t yp es sup por t ed b y RSVP. Pub lish er: Cisco Press

Under and RSVP's diff er ent Pub Dat e: st Sep tem ber 1 1, 2 003

filt er and st y le t yp es.

I SBN: 1- 58 705 -1 19 -2

Ex plain t he p ur pose of RSVP t unn eling . Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background The Resour ce Reser vat ion Pr ot ocol ( RSVP) is a net w or k- con t rol pr ot ocol t hat enables I nt er net app licat ions t o obt ain d if fer ing qualit ies of ser v ice ( QoS) f or t heir dat a f low s. Su ch a cap abilit y r ecogn izes t hat diff er ent applicat ions h ave d iff er ent net w ork perf or man ce requ ir em en t s. Som e •app licat ions, Table of ing Content includ t he sm or e t r adit ional in t eract iv e and bat ch app licat ions, r equir e r eliab le •deliver y of dat I ndex a but do not imp ose any st r ingent r eq uirem ent s f or t he t imeliness of deliv ery . INewer nt e rn et ap w orplicat k ing Te chnologie H a ndbook th Edit ion ion t y pes, sincludin g ,vFour ideoconfer en cin g, I P t elephon y, and ot her f orm s of m ult im ed ia comInc. mu nicat ions r eq uir e alm ost t he ex act opp osit e: Dat a deliv ery m u st be t im ely but By Cisco Systems, not necessar ily r eliab le. Thus, RSVP w as int end ed t o pr ovid e I P net w or ks w it h t h e capabilit y t o supp ort t he diver gent per for m ance r eq uir em ent s of d if fer ing applicat ion t yp es. Pub lish er: Cisco Press Sep tem ber 1 1, 2 003 I t isPub imDat pore:t an t t o not e t h at RSVP is not a rou t ing pr ot ocol. RSVP w or k s in con jun ct ion w it h I SBN: 58 705and -1 19 -2 r out ing pr ot1-ocols inst alls t h e eq uiv alent of dy nam ic access list s along t he r ou t es t hat rou t ing Pages: 11 28lat e. Th us, im plement in g RSVP in an ex ist in g net w ork does not requ ire m igr at ion pr ot ocols calcu t o a new r ou t in g pr ot ocol.

Resear cher s at t he Univer sit y of Sout her n Califor nia ( USC) I nf orm at ion Sciences I nst it ut e ( I SI ) and Xer ox' s Palo Alt o Resear ch Cen t er ( PARC) or ig inally con ceiv ed RSVP. The I nt er net En gineer ing Forof ce t (he I ETF) v er sion of RSVP it s RFC The u pdat ed Task edit ion b estsubsequent - selling all-ly in-specified one net wan orkop ingenr ef erence p rov idesincover age220 of 5 based direct ly on t he USC and PARC ver sion . RSVP oper at ion al t op ics d iscussed in t his chap t er essent ial an d cu t t ing- edg e t ech nologies. include dat a f low s, qualit y of serv ice, session st ar t up, reserv at ion st yle, and soft st at e im plem ent at ion .Figur e 50 - 1 illust r at es an RSVP env ir onm en t . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . cov erag e ofI im t ant P er ande d EAP FiguNew r e chapt 5 0 -1er. sI include n RSVP, Host n fpor or m a ttiopics on I like s DVoI el iv t o Rece iv e r s ove r Da ta Flow s Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

RSVP Data Flows I n RSVP, a dat a f low is a sequ en ce of dat agr am s t hat hav e t h e same sou rce, dest inat ion ( r egar dless of w h et h er t hat dest in at ion is on e or m or e phy sical m ach in es) , and qualit y of ser v ice. QoS r eq uir em ent s are com m unicat ed t hr ough a net w ork via a flow specif icat ion , w hich is •a d at a st r uct Table Content ur e uof sed by inst er net w or k host s t o r eq uest special ser v ices fr om t he int er net w or k. A •flow sp ecificat I ndex ion descr ibes t he lev el of ser v ice r equir ed f or t h at d at a f low . This descr ipt ion t ak es It he nt e rn w or chnologie H afic ndbook , Four Editt ion foretm ofk ing oneTeof t hr ee st raf t yp es. Ththese r aff ic t y pes ar e ident if ied by t h eir cor r espon ding RSVP of serv By Ciscoclass Systems, Inc.ice: Pub lish er: Cisco Press Dat e: 1 .PubBest - efSep fortem t ber 1 1,

2 003

I SBN: 1- 58 705 -1 19 -2

2 . Rat e- sensit Pages: 11 28 iv e 3 . Delay- sensit ive Best - ef for t t raf fic is t rad it ional I P t raf fic. App licat ions in clu de f ile t ran sf er ( such as mail t r ansm issions) , d isk m oun t s, int er act iv e logins, an d t ran sact ion t r aff ic. These t yp es of The licat u pdat ed requ edit ion t heleb est - selling one net w ork ef erence p rov cover age of iev e app ions ir e rof eliab deliv er y of alldatina regar dless of ing t her am ou nt of t imides e n eeded t o ach ial anyd. cu t t ingedg t ech tessent hat deliver Best - ef for t ter af fic nologies. t y pes r ely upon t h e nat iv e TCP mechanism s t o reseq uence dat ag r ams receiv ed ou t of or der , as w ell as t o r eq uest r et r ansm issions of any dat agr ams lost or dam aged in t ran sit . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom iceive t o tex Rat e- nov sensit rafpert fic r. equ ir es a guar ant eed t ran sm ission r at e f rom it s sour ce t o it s d est inat ion . An ex am ple of such an applicat ion is H. 32 3 videoconf er encing, wh ich is designed t o r un on I SDN New s 31 include cov of im opics like andI PEAP ( H. 320 ) orchapt ATM er ( H. 0) , b ut iserag alsoe foun d por on ttant h e Itnt er net anVoI d mPany b ased int r anet s. H. 323 encoding is a con st an t ( or nearly const an t ) r at e, and it requ ires a con st ant t ran sp or t r at e such as Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age is av ailab le in a cir cuit - sw it ched n et w or k . By it s v ery nat ur e, I P is p ack et - sw it ch ed . Thus, it lack s t he mechanism s t oCisco su ppor const bitide ratleader e of serinv ice applicat Aut h ored by Sy tstaems, want or ldw netfwororany kingg fiven or t he I n t er nion' et . s dat a flow . RSVP en ables con st ant bit - r at e ser v ice in pack et - sw it ched net w or ks v ia it s rat e- sensit iv e lev el of v ice. Thorisk in ser ice is som et im es r book efer red t o as ant, eed - rat ser v ice . refer ence t hat Iser n t ern et w g vTech nologies Hand , Four t h guar Ed it ion is a bit com preehensive enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Delay - sen sit iv e t r afer fict he is t traf fics,t hat equt s, ir es t im eliness y and t h atinv ar ies it r atw e ork ing t echnologies. Mast er m conrcep t echn ologies,ofandeliver d devices used t oday ' ss net accor d in gly . MPEGI I video, f or ex amp le, av er ages about 3 t o 7 Mb ps, depend ing on t he ament ount indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm . of chang e in t he pict ur e. As an exam p le, 3 Mb ps m ight be a pict ur e of a paint ed w all, alt houg Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,h 7 Mb psspeed, w ouldt hbe equir is edafor a plet pict euran e of aves e er ocean. I video souare rces sen dt ial keyt o all and is rbook com d uwpt o- don at et hr ef ence tMPEGo t he tIop ics t hat essen and delt a fr am es. Ty pically, 1 or 2 k ey fr am es per second d escrib e t he w h ole pict ur e, and 13 or net w or kin g p rof essionals, r egar dless of ex pert ise. 28 f ram es ( k now n as delt a f r ames) d escr ib e t he ch ange f r om t he key f ram e. Delt a f r ames ar e usually ssub an tain iallya sm aller han f rding ames. a rand esultWAN , r at es omly f tr hame Reader w illstobt g reat er tun derk ey st an of As LAN n etvwarory kquit ing,epaarbit t icufrlar e to fr am e.arAe,sing leocols, fr am e,and how ever , r eq esedd .eliv w itent h inalat ech sp ecific t iminf e or f r ame or tis heprCODEC har dw pr ot ser v ices invuir olv Fu ery ndam nology mat ion ov ided on ( codedecode) is incapab doing it s serv j ob.ices, A sp in ecific r iordet it y ailed m ustdescr be negot f or a- fr ions am e a b r oad r ang e of int egr al le syof st em s and cludping ipt ioniat s,ed rev iewdelt quest r aff vices surppor iv e tand r aff ic ref er rr esou ed t or ces as cont tt o enic. su RSVP re conser cept comp eh ent ing siondelay and -r sensit et en t ion, adare dit ional f or rfuolledrt herdelay st udyser . v ice ( nonerag - r ealt imalso e ser v ice) andn ot pr edict ser v ice ( realt imconcep e ser v ice) . Cov e is ext end ed only iv t oe new n et wor k ing t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct ivData it y an dFlows im pr ov eProcess eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient RSVP decisions for t h eir net w ork s. Unlike r ou t in g pr ot ocols, RSVP is designed t o m anag e flow s of d at a r at her t h an mak e d ecision s for each indiv idual dat agr am . D at a f low s con sist of d iscr et e session s bet w een specif ic sour ce and dest inat ion m ach in es. A session is m or e specif ically d ef ined as a simp lex f low of dat agr ams t o a par t icular dest inat ion and t r anspor t lay er pr ot ocol. Thu s, session s ar e ident ified by t h e follow ing dat a: dest inat ion addr ess, pr ot ocol I D, and d est inat ion por t . RSVP supp or t s bot h un icast and

m ult icast simp lex sessions.

NO TE • •

I t is im por t an t t o not e t h at RSVP sessions ar e sim plex . Th us, a b idir ect ional ex chang e Table of Content s of dat a bet w een a pair of m ach ines act ually con st it ut es t w o separ at e RSVP sim p lex I ndex sessions.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

A mPub u ltlish icast session sen ds a cop y of each dat ag ram t r ansmit t ed by a single sender t o m ult iple er: Cisco Press dest inat ions. A unicast session feat ur es a sing le sou rce an d d est inat ion m achine. An RSVP sou rce Pub Dat e: Sep tem ber 1 1, 2 003 and dest inat ion add ress can cor r espon d t o a uniqu e I nt ern et host . A single host , how ev er , can 58 705 -1 19 -2 cont ainI SBN: m ult1-iple logical sen der s and r eceiver s dist ingu ish ed by por t n um bers, w it h each p ort Pages: 28 onding t o a d if fer ent ap plicat ion . Giv en t h at RSVP t r acks su ch app licat ion- sp ecific nu mb er cor r11esp inf orm at ion, it is p ossible f or a u nicast session t o r esult in dat a b ein g f or w ard ed t o mu lt iple app licat ions wit h in t h e same dest in at ion h ost .

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

RSVP Quality of Service I n t he cont ex t of RSVP, qu alit y of ser v ice ( QoS) is an at t ribu t e specif ied in flow sp ecificat ions t hat ar e used t o det er min e t he w ay in w hich dat a in t er chan ges ar e hand led by p ar t icipat in g ent it ies ( r out er s, receiv ers, an d sender s) . RSVP is used t o specif y t he QoS by bot h host s and •r out er s. HostTable Content s useofRSVP t os r equest a QoS lev el fr om t he net w ork on b eh alf of an ap plicat ion dat a •st r eam . RoutIer ndex s use RSVP t o d eliv er QoS r equest s t o ot her r out er s along t he p at h( s) of t he dat a Ist ntr eeam rn et .w Ior ing Te chnologie s Hm a ndbook , Four nk doing so, RSVP aint ains t h th e rEdit oution er and host st at e t o pr ovide t he r equest ed serv ice. By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

RSVP Session Startup To in it iat e an RSVP m ult icast session, a r eceiver f irst joins t he m ult icast gr oup specif ied b y an I P dest inat ion addr ess by u sing t h e I nt ern et Gr oup Mem ber sh ip Pr ot ocol ( I GMP) . I n t he case of a un icast session , unicast r out in g ser ves t h e fu nct ion t hat I GMP, coupled wit h p rot ocol•independ en t Table of Content s , ser v es in t h e m ult icast case. Af t er t he r eceiv er j oins a gr oup, a m u lt icast ( PI M) •pot ent ial send I ndex er st art s send in g RSVP p at h messag es t o t h e I P dest inat ion addr ess. The r eceiver Iapp nt e rn et wion or k ing Te chnologie , Four Edit licat r eceiv es a pats hH amndbook essage andth st ar ion t s sending ap pr opr iat e r eserv at ion- r equ est m essages specifInc. y in g t he desired flow descr ipt or s using RSVP. Af t er t he send er applicat ion By Cisco Systems, r eceives a reserv at ion- r equest m essag e, t he sender st ar t s sending dat a pack et s. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

RSVP Reservation Style Reser v at ion st y le r efer s t o a set of cont r ol op t ions t h at specif y a num ber of sup por t ed par am et er s. RSVP suppor t s t w o m ajor classes of r eser v at ion: dist in ct r eserv at ions an d shar ed r eser vat ions. D ist inct reserv at ions in st all a f low for each relevan t sender in each session. A •shar ed r eser v Table Content at ionof is u sed sby a set of sen ders t hat are k now n not t o in t erf ere w it h each ot h er . •Figur e 50 - 2 illust I ndexr at es dist inct an d sh ared RSVP r eser v at ion- st y le t yp es in t h e cont ext of t heir Iscop nt e rne.et w or k ing chnologie s H av ndbook Four thscop Edit ion Each suTe ppor t ed reser at ion , st y le/ e com b in at ion is d escr ibed f ollow in g t h e illu st rat ion . By Cisco Systems, Inc.

Pub lish er: Cisco Press

Figu r e 5 0 -2 . RSVP Su ppor t s Bot h Di st inct Re se r va t i ons a nd Sh ar e d Pub Dat e: Sep tem ber 1 1, 2 003 Re ser v at ion s I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Wildcard-Filter Style

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The w ildcar d- f ilt er ( WF) st y le sp ecifies a shar ed reserv at ion w it h a w ild car d scop e. Wit h a WFI n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat st y le reser v at ion, a sin gle r eser vat ion is cr eat ed int o w hich f lows fr om all u pst r eam send er s ar e enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing m ixed. Reser vat ion s can b e t hou ght of as a sh ared pipe w h ose size is t h e lar gest of t he r esour ce t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing r eq uest s for t hat lin k fr om all r eceiv er s, ind ep en dent of t he nu m ber of sen ders. Th e r eserv at ion indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . is pr opag at ed u pst r eam t ow ard all sender h ost s and is aut om at ically ex t ended t o n ew send er s as Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, t hey ap pear. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Fixed-Filter Style har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b rfix oad intstegr syecifies st em s aand clud ailed descrscop ipt ion rev quest ions The ed r- ang filt ere (of FF) y lealsp d istserv in ct ices, r eserin vat ioning w itdet h an ex plicit e.s,Wit h iew an FFst yle tr oeser en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . vat ion , a d ist inct r eserv at ion r eq uest is creat ed for d at a p ack et s f rom a par t icular sender . Cov ext end ot monly wor klist ing of concep t s,s.but t o rold er , at legacy The erag r eserevis atalso ion scope ised d etn er inedt ob ynew an nexetplicit sender Thealso t ot al eserv ion on a link syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in hich for a g iv en session is t he t ot al of t h e FF reser v at ions f or all r equest ed sender s. FF reser v atwions pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease t hat ar e r eq uest ed by diff er ent receiv ers but t hat select t h e same send er m u st be m er ged t o pr odu it y le anreser d im pr ovion e eff shar e ct a iv sing v at in iciency, a giv en help nod ing e. t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Shared-Explicit Style The shar ed - exp licit ( SE) st y le r eser v at ion sp ecifies a sh ared r eserv at ion en vir onm ent w it h an

exp licit reser v at ion scope. Th e SE st y le cr eat es a sin gle r eserv at ion int o w hich f lows fr om all up st r eam sender s ar e m ix ed. As in t h e case of an FF r eser vat ion , t he set of sender s ( and , t her efor e, t he scope) is specified ex plicit ly by t he receiv er m akin g t h e r eser vat ion.

RSVP Reservation Style Implications •WF an d SE arTable e botofhContent shar eds reser v at ions t h at ar e ap pr opr iat e for mu lt icast applicat ions in w hich •app licat ion- specific I ndex const r aint s m ak e it u nlikely t h at m ult iple d at a sour ces w ill t ran sm it Isimu nt e rnltetaneously. w or k ing Te An chnologie s Hle a ndbook Four th Edit ionfer en cing , in w hich a lim it ed num ber of p eop le ex amp m ig ht , be aud iocon tBy alk at once. Each receiv er m ig ht issue a WF or SE r eser v at ion r equest t w ice f or one au dio Cisco Systems, Inc. chann el ( t o allow som e ov er speak in g) . Th e FF st yle cr eat es in dependent r eserv at ions for t h e flow s f r om dif ferent sen der s. The FF st yle is m or e app r opr iat e for v ideo sign als. Unf or t unat ely , it Pub lish er: Cisco Press is not possible t o m er ge shar ed r eser v at ions w it h dist inct r eser v at ions. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

RSVP Soft State Implementation I n t he cont ex t of an RSVP- enab led net w or k, a soft st at e r efer s t o a st at e in r out er s and end nod es t hat can be upd at ed by cer t ain RSVP m essages. The sof t st at e ch aract er ist ic p er m it s an RSVP net w ork t o sup por t d yn amic g rou p mem ber sh ip chan ges and adap t t o chang es in r out ing . •I n general, t he Table of Content soft st at e iss m aint ained by an RSVP- b ased net w or k t o enab le t he n et w or k t o •chang e st at es I ndex w it hout con sult at ion wit h end point s. This cont r ast s w it h a circuit - sw it ch Iar ntch e rn w or k inginTew chnologie H a ndbook Four th a Edit ion and, in t he event of a f ailur e, places a new call. itet ect u re, hich ansend point ,places call By Cisco Systems, Inc.

RSVP pr ot ocol m echan ism s p rov ide a gener al facilit y for cr eat ing and m aint aining a dist rib ut ed r eser vat ion st at e acr oss a m esh of m ult icast and un icast deliv ery pat hs. Pub lish er: Cisco Press

Pub Datain e: Sep ber 1at 1, ion 2 003st at e, RSVP t r ack s a soft st at e in r out er and host nodes. The RSVP soft To m aint a tem reserv I SBN: 158 705 -1 19 -2 st at e is cr eat ed and m ust b e per iodically r efr esh ed by pat h and r eser vat ion - requ est m essages. I f no m at Pages: ch ing11ref 28 resh messages arr iv e befor e t h e exp ir at ion of a cleanup t im eout in t er v al, t he st at e is delet ed . The sof t st at e also can be delet ed as t he r esult of an exp licit t ear d own m essage. RSVP period ically scan s t he sof t st at e t o bu ild an d f or war d pat h an d r eser v at ion- r eq uest r efr esh m essages t o su cceeding hops.

When a r out e ch anges, t h e next pat h m essage in it ializes t h e pat h st at e on t he new r out e. Fut u re The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of r eser vat ion - requ est m essages est ab lish a r eser v at ion st at e. Th e st at e on t he n ow - unu sed essent ial an d cu t t ing- edg e t ech nologies. seg m en t is t im ed ou t . ( Th e RSVP specificat ion r equ ir es init iat ion of new r eser vat ion s t hr oug h t he net w or k 2 seconds aft er a t opology chan ge. ) Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Whennov st at e chang es occur , RSVP pr opag at es t hose chang es fr om end t o en d w it h in an RSVP ice t o ex pert . net w or k w it hout delay . I f t he r eceived st at e dif fer s fr om t h e st or ed st at e, t he st or ed st at e is up datNew ed. I chapt f t h e er result mod ifies t he reefr m essages t o be g en erP atand ed, ref resh m essag es are s include cov erag ofesh im por t ant t opics like VoI EAP gener at ed an d f or w ard ed im m ed iat ely . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

RSVP Operational Model Under RSVP, resour ces ar e r eser v ed f or sim p le dat a st r eam s ( t hat is, unid ir ect ion al dat a f low s) . Each sen der is logically d ist in ct fr om a r eceiver , bu t an y applicat ion can act as a sen der and a r eceiver . Receiv ers are responsible f or r eq uest in g r esour ce reser v at ions. Figur e 50 - 3 illust r at es •t his g en er al operat Table ofion Content s ir on ment , w hile t he sub sequ en t sect ion p rov ides an out line of t he al env •specif ic seq uence I ndex of ev ent s. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu e Cisco 5 0 -3 . Th e RSVP O pe r at i ona l Env ir on me n t Rese r ve s Re sou r ce s Pub lishrer: Press Pub Dat e: Sep tem ber 1 1, 2 003 f or Un idi r ect ion al D at a Fl ow s I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

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The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

General RSVP Protocol Operation

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g rpeserv r ofessionals o un derst and d imsplem enan t cont em por ar yonintcon er net The RSVP r esou rceat ion pr tocess init iat ionan begin w hen RSVP daem su ltwsork t heing t echnologies. Mast er t he m s,ain con cepes. t s, A t echn d devices used t oday s net w ork local r out ing pr ot ocol( s) ttoerobt r out hostologies, sen ds I an GMP m essages t o in j oin a m' ult icast gring oup indu st ry . Lear n how t o incor e int ces er net w or kin g tdechn LAN/ WAN env. irEach onm ent and RSVP m essages reserpor v e at r esour along t he eliv erolog y p ies at h(ins)t of raom t hat gr oup r out. er e w it h new anicipat d u pdat s on secur y , st or age,incom opt ical waorpkack in g,etscalabilit y, et tCom hat plet is capable of p art in ged in chapt r esouer rce r eser vatition p asses in gnet d at s t o a p ack and speed, t h tish en book is aescom pletas e an d u p- t od ataepack r ef eretence t o t he t op icsRSVP t hat pack are essen t ial t o all classifier and qu eu t hem n ecessar y in scheduler. The et classifier net er w or kines gp rof ressionals, r egarclass dlessfor of each ex pertpacket ise. . Th e RSVP schedu ler allocat es r esour ces for det min t he out e an d QoS t r ansm ission on t he par t icular d at a link lay er m ed iu m used b y each int er face. I f t he d at a link Reader w ill obt ainitas g reat er unmder st an ding LANilit and n etet w or k ing, p aris t icu lar ly t h e f or lay er msedium has ow n QoS anagem en t of capab y , tWAN h e pack sch ed uler responsible har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on negot iat ion w it h t he d at a link lay er t o ob t ain t he QoS r eq uest ed by RSVP. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tThe o enschedu su re con r ehes en pack sion et and r etsm en ission t ion, and ad dit esoupassiv r ces f or fued rt her udy . as a lercept it selfcomp allocat - t ran capacit y ional on a rQoSem ium st , such Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy leased lin e, and also can allocat e ot her sy st em resour ces, such as CPU t im e or buf fer s. A QoS syst em s, ovid in goraiginat m or ein rgealist pict ur of t he real- wion, or ldisn petassed w or k ing onmRSVP ent s in w hich r eq uest , tpr y pically in a ic receiv erehost applicat t o ten h evir local pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease im plem ent at ion as an RSVP daem on. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient The RSVPfor pr ot t hen is us.sed t o p ass t he r equest t o all t h e nodes ( r out er s an d h ost s) along t he decisions t hocol eir net w ork r ev er se d at a p at h( s) t o t h e dat a sou rce( s) . At each node, t h e RSVP pr ogr am app lies a local decision pr oced ur e called adm ission cont r ol t o det erm ine w h et h er it can su pply t h e r eq uest ed QoS. I f ad mission cont r ol su cceed s, t he RSVP pr ogr am set s t h e par am et er s of t he packet classifier and scheduler t o obt ain t he d esir ed QoS. I f ad mission cont rol fails at any nod e, t he RSVP pr ogr am r et ur ns an er ror in dicat ion t o t he applicat ion t h at or iginat ed t he requ est .

RSVP Tunneling I t is im possible t o deploy RSVP or any n ew pr ot ocol at t he sam e m oment t hr oug hout t he en t ire I nt er net . I ndeed, RSVP m ight nev er be deploy ed ev er y w here. Th er efor e, RSVP m ust p rov ide corr ect p rot ocol op er at ion even w hen t w o RSVP- capab le rou t ers ar e in t er connect ed v ia an ar bit r ar y clou d of n on- RSVP r out ers. An int er m ed iat e clou d t hat does not su ppor t RSVP is • Table of Content s incapab le of p er f orm ing r esou rce r eser v at ion, so ser vice gu aran t ees cann ot b e m ade. How ev er, • I ndex if such a clou d has suf ficient excess cap acit y , it can p rov ide accept able an d u sef ul r eal- t ime I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion ser v ice. By Cisco Systems, Inc.

To su ppor t con nect ion of RSVP net w ork s t h r ough non - RSVP n et w or k s, RSVP su ppor t s t u nneling, w hich occur s au Press t om at ically t hr ou gh non- RSVP clouds. Tu nneling requ ires RSVP and non - RSVP Pub lish er: Cisco r outPub er sDat t oe:f or w ard essag es t owar d t he dest in at ion ad dr ess b y using a local r out in g t able. Sep tem berpat 1 1,h2m 003 When a p at h message t r av er ses a non - RSVP cloud , t he pat h m essage copies carr y t he I P I SBN: 1- 58 705 -1 19 -2 add ress of t he last RSVP- capable r out er . Reserv at ion- r equ est messag es are for w ard ed t o t he Pages: 11 28 nex t u pst r eam RSVP- cap able r out er . Tw o ar gu m en t s hav e been offer ed in def en se of im plem en t ing t unn eling in an RSVP env iron ment . Fir st , RSVP w ill be d ep loy ed sp orad ically r at her t h an u niv er sally . Second, by im plem ent in g cong est ion cont r ol in sit u at ions in w hich cong est ion is a k now n pr ob lem , t u nneling can m ade m orion e eff iv e. The be u pdat ed edit ofect t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Spor adic, or p iecemeal, d ep loy m ent means t hat som e p art s of t he n et w or k w ill act ively im plem ent RSVP befor e ot her p art s. I f RSVP is r eq uir ed end t o en d, no benefit is achiev able Connear ciselyovuniv er v iew s of t echn t o ely n et unless wor k ingearly pr ofession at sh allows lev els, f rom w it hout ersal d ep loymolog ent ,ies whessen ich ist ial un lik d ep loy als m ent icebenefit t o ex pert subst nov an t ial s. . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Weighted Fair-Queuing Solution Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Hav inAut g t he t echnology orce ef fect iv eide r esou rce in r eser ( such h ored by Ciscot oSyenf st ems, w or ldw leader netvwat orion king f or t as he Cisco's I n t er n etw. eigh t ed f air qu eu in g schem e) in a locat ion t hat pr esent s a bot t leneck can h ave r eal p osit iv e eff ect s. I n t ern et wgor in g Tech Four t h Ed itision , hin is a acom ehensive ence hat Tun nelin p kr esent s a nologies risk on ly Hand wh enbook t h e ,bot t leneck w it nonpr- RSVP d omrefer ain an d t ht e enables netcannot w or kin gbep rav ofessionals t o eun and ran d im en env t cont em por y int netawt ork ing bot t leneck oided. Figur 50derst - 4 illust at es anplem RSVP ir onm en tarf eat urer ing u nnel t echnologies. Mast er tnet he w t erormks. s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing bet w een RSVPb ased indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net wFigu or kinrgep rof r egar dless ofirex pert 5 0essionals, -4 . An RSVP Env on mise. en t Ca n Fe at ur e a Tu nn el Be t w ee n

RSVP- Base d N et w or k s

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

RSVP Messages RSVP su ppor t s f our b asic messag e t y pes: r eser vat ion - requ est m essages, pat h m essages, err or and conf ir m at ion m essages, and t eard ow n m essag es. Each of t h ese is describ ed br iefly in t he sect ions t hat follow . •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Reservation-Request Messages By Cisco Systems, Inc.

Ar eser vat ion- r equest m essage is sent by each receiv er host t owar d t he send er s. This m essag e Pubslish Cisco Press follow iner:r ev erse t h e r out es t hat t he dat a packet s u se, all t he w ay t o t he sender h ost s. A Pub Dat e: Sep tem ber 1m 1,essage 2 003 r eser vat ion - requ est m ust be deliver ed t o t he send er h ost s so t hat t h e host s can set up I SBN: 158 705 -1 19 -2 app rop riat e t raf fic- cont r ol p aram et ers for t h e fir st h op. RSVP does not sen d any posit iv e ackn ow ledg11 m28 en t m essages. Pages:

Path Messages The u pdat edit ion ofist he b est all- inw ork p rov rides cover age An RSVP pated h m essage sent by- selling each send er one alon net g t he uning icastr eforerence m ult icast out es pr ov id edof b y essent ial an d cu t t ingedg e t ech nologies. t he rou t ing pr ot ocol( s) . A pat h m essag e is used t o st or e t he p at h st at e in each n ode. The pat h st at e is used t o r out e reser v at ion- r equest m essag es in t h e rev erse dir ect ion . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Error and Confirmation Messages

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Thr ee err or an d con fir mat ion m essage for m s ex ist : p at h- er ror messages, reser v at ion- r equest Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age err or m essag es, an d r eser v at ion- r equest ack now led gm en t m essag es. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Pat h- er r or m essages r esult f r om pat h m essages an d t rav el t ow ar d send er s. Pat h- er r or m essages ar e r out ed hop by h op u sin g t h e pat h st at e. At each hop, t he I P dest in at ion ad dr ess is t he I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat un icast addr ess of t he pr ev iou s hop . enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Reser v at ion - r eq uest err or m essages r esult f r om r eser vat ion- requ est messages and t r avel t owar d indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . t he receiv er. Reser vat ion - r eq uest err or m essag es ar e r out ed hop b y hop using t he r eser v at ion Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, st at e. At each hop, t he I P d est inat ion ad dr ess is t h e unicast ad dr ess of t h e nex t - hop nod e. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all I nf orm at ion carr ied in er ror messag es can includ e t he f ollow ing : net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s wission ill obt ain a eg reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Adm failur har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Band widet hof unav ailable t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e ice is also end ed Serv not ext su ppor t edn ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Bad flow oper specificat ion and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr of essionals at e. Tools pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Am bigu h w ork s. decisions for ous t h eirpat net Reser v at ion - r eq uest ackn ow ledgm ent m essages ar e sent as t he result of t he app ear ance of a r eser vat ion - con fir m at ion ob ject in a r eser v at ion - r eq uest m essage. This ack now ledgm ent m essage cont ain s a copy of t he r eser vat ion conf irm at ion. An ack now ledgm ent message is sen t t o t he unicast add r ess of a receiv er host , an d t he add ress is obt ain ed f rom t he r eser v at ion conf ir m at ion object . A reserv at ion- r equest ack now ledgm ent message is f orw ar ded t o t h e

r eceiver h op b y hop ( t o accom m odat e t h e hop - by - hop int egr it y - ch eck m ech anism) .

Teardown Messages RSVPt ear dow n m essages r em ove t he pat h an d reser v at ion st at e w it hout w ait in g for t h e cleanu p t im eou t p er iod. Tear dow n m essages can be init iat ed by an app licat ion in an end syst em ( sender •or r eceiv er ) or Table Content a r of out er as st he r esu lt of st at e t im eout . RSVP supp or t s t w o t y pes of t ear dow n •m essages: p at I ndex h- t ear dow n and reserv at ion- r equest t ear dow n . Pat h- t ear dow n m essages d elet e It he nt e rn et w ing s Hes a ndbook , Four th pat h or stkat e Te ( wchnologie hich delet t h e reserv atEdit ion ion st at e) , t r avel t ow ar d all r eceiver s dow n st r eam f rom t heCisco point of in it iat By Systems, Inc.ion, and ar e r out ed like p at h messages. Reser v at ion - r eq uest t eard ow n m essages d elet e t h e r eserv at ion st at e, t r avel t owar d all m at ching sen der s upst r eam fr om t he point earCisco dowPress n in it iat ion, and ar e r out ed like cor r espon ding r eser vat ion- requ est messages. Pubof lishter: Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

RSVP Packet Format Figur e 50 - 5 illust r at es t he RSVP p ack et f orm at . The sum m ar ies t h at f ollow out line t he header and obj ect fields illust r at ed in Figur e 50 - 5. •

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Figu r e 5 0 -5 . An RSVP Pack et For m a t Con si st s of M essage H ea de r s an d O bje ct Fie lds

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

[ View full size im age]

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age AutMessage h ored by Cisco Sy st ems, w or ldw ide leader in RSVP Header Fields

net w or king f or t he I n t er n et .

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat RSVP message header f ields are com pr derst ised of t h an e follow ing: en t cont em por ar y int er net w ork ing enables net w or kin g p r ofessionals t o un and d im plem t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu stVry Lear n how at e ing int ert he netpr w or t echn olog iesber in t o( cur a LAN/ e .rsion— A 4- bt oit incor f ield por indicat ot kin ocolg ver sion n um r en t WAN ly ver env sionir1onm ) . ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book a com an d cur u p-rten o- dt ly at defined. e r ef er ence t o t he t op ics t hat are essen t ial t o all Fla gs— A 4b it fisield w it hplet n oef lags net w or kin g p rof essionals, r egar dless of ex pert ise. Ty pe — An 8 - bit field w it h six possible ( in t eg er ) valu es, as sh own in Table 5 0- 1. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also Tab ext end t o new wor ke ingTy concep t s, ld butVa also t osold er , legacy le ed 5 0n -ot1 only . RSVP M neet ssag pe Fie lue syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

V a lue Me ssa ge Ty pe

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1

Pat h

2

Reser v at ion- r equest

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Pat h- er r or

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Reser v at ion- r equest er ror

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

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Reser v at ion- t ear dow n

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Reser v at ion- r equest ack now led gm en t

By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Che ck1-sum —-1A I SBN: 58 705 1916 -2 - bit field r epr esent ing a st an dar d TCP/ UDP checksu m over t he cont ent s of t he RSVP m essage, w it h t h e ch eck sum f ield r ep laced by 0. Pages: 11 28 Le ng t h— A 16 - bit field r epr esent ing t h e len gt h of t his RSVP pack et in by t es, in clud ing t he com mon header an d t he v ar iab le- lengt h ob ject s t hat follow . I f t he Mor e Fr agm ent ( MF) f lag is set or t h e Frag ment Of fset f ield is non zer o, t h is is t he leng t h of t he cur r en t f rag m en t of a lar ger m essage. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essentSe ialnd anTTL— d cu t t ingt ech nologies. An 8edg - bite field ind icat ing t h e I P t im e- t o- live ( TTL) v alue w it h w hich t he m essage w as sen t . Con cisegeovIer v iew t echn olog essenat ial n etared wor kby ingallprfrofession els, f rom Me ssa D— A s32of- bit field pr ies ov iding lab telo sh agm entals s ofatonall e lev m essage f rom nov ice t o ex pert . a g iven next / pr ev ious RSVP hop . New include cov erag of im opics P and Mor echapt fr ager m se nt s ( MF) f la g—e Low - orpor dert ant bit tof a 1-like by t eVoI w ord w itEAP h t he ot her 7 high- ord er bit s sp ecified as r eserv ed. MF is set on for all b ut t he last f r agm en t of a m essage. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Fra gm en t of fset — A 24 - bit field r epr esent ing t h e by t e of fset of t he fr agm ent in t h e Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . m essage I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing RSVP Object t echnologies. MastFields er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w itfhield new u pdat ed chapt s on secur RSVP object s aran e dcom p rised of t h eerfollow ing: it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Le ng t h— I s a 16 - bit field cont ainin g t he t ot al object leng t h in by t es ( m ust alw ay s b e a Reader ill obt a g reat unat derleast st an ding m sultwiple of ain 4 and m usterbe 4 ) . of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Clarssd enalt ifies he sob jectserv class. ob ing ject det class has a nam e. An RSVP a b r oad angneum of — intIegr sy st tem and ices,Each in clud ailed descr ipt ion s, rev iew quest ions imre plem at ion m ust recognize 0- 2. r ces f or fu rt her st udy . t o en su conent cept comp r eh en sion andt he r et classes en t ion, list andedadinditTable ional 5r esou Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy The h ight h or e ClassNuicmpict field m ines ion a knode shou ld t ake it w does syst em s, or pr der ovidbinitg of am e r ealist ur ed et ofert he real-wwhat or ldact n et w or ing en vir onm ent sif in hich not ecogn ize oper t he ClassNum and of an ject . f or opt im izing syst em per for m ance w ill incr ease pr of ressionals at e. Tools guob id elines pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. C- t y pe — Obj ect t yp e, uniq ue w it hin Class- Nu m. The m ax imu m obj ect con t ent leng t h is 65 528 by t es. The Class- Num and C- Ty pe f ields ( t oget her w it h t he f lag b it ) can be u sed t oget h er as a 16 - bit num ber t o defin e a u nique t yp e for each object . Obj e ct con t en t s— The Leng t h, Class- Num , an d C- Ty pe f ields specify t h e for m of t he obj ect cont ent . Ref er t o Table 5 0- 2 f or d ef init ions of t h e classes of object s t h at can be

included in t he obj ect cont ent s.

Tab le 5 0 - 2 . RSVP O bje ct Cl asses • Obj e ct Cl a ss Table ofDContent s i on e scri pt • I ndex

Null Con t ains a ClassNum of 0, I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ionan d By

it s C- Ty pe is ign ored. I t s len gt h m ust b e at least 4 but can b e any m ult ip le of 4. A null ob ject can appear an yw her e in a Cisco Systems, Inc. seq uence of obj ect s, an d it s con t en t s w ill be ign or ed by t he r eceiver .

Session Pub lish er: Pub Dat e:

Con t ains Cisco Press

t h e I P dest inat ion addr ess and possib ly a g en er alized dest inat ion por t t o d ef ine a sp ecific session for t he ot h er object s t hat f ollow ( requ ired in Sep tem ber 1 1, 2 003 ever y RSVP message) .

I SBN: 1- 58 705 -1 19 -2

RSVPPages: Hop

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Tim e Values

Car r ies t he I P ad dr ess of t h e RSVP- capab le node t h at sent t his m essage. I f pr esent , con t ains v alues for t he r efr esh per iod an d t he st at e TTL t o ov er r ide t h e defau lt v alues.

St y le Defin es t he r eser vat ion st y le plus st y le- specific inf or mat ion t h at is n ot a ion or allfilt erspecificat ion ing ob ject ( in cludped a r eser v at ionThe u pdat ed edit ionflow of -t specificat he b est - selling in- one net w ork r ef erence rovinides cover age of r eqedg ueste tmech essage) . essent ial an d cu t t ingnologies. Flow Defin es a desir ed QoS ( in clu ded in a r eser v at ion- r equest m essage) . Specificat ion Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom . es a subset of session- d at a p ack et s t hat should r eceive t he desired QoS Filt ernov ice t o ex pert Defin Specificat ion ( specif ied by a f low - specificat ion ob ject w it hin a reser v at ion- r equest New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP m essage) . Cov erag e of cut t ing edge t echn e opt et worsom k inge and stional or aged em ult iplex ing Sender Con t ains a send erologies I P addrlik ess andical pernhaps add it Temp lat e inf orm at ion t o id en t ify a sen der ( included in a pat h m essage) . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Sender TSPEC Defin es t he t r aff ic char act er ist ics of a sen der' s dat a st r eam ( in clu ded in a I n t ern et w or k in g Tech Hand patnologies h m essage) . book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Adspec Cart he r iest eradv t isincep g dat in a ologies, pat h m essage. t echnologies. Mast er m s,er con t s, at echn an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog t o avLAN/ WAN env ireronm Er r or Specifies an er r or ( included in a pat h - err ories or in reser at ionr equest ror ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Specificat ion m essage) . and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net Policy w or kin Datgap rof essionals, Car r ies rin egar for m dless at ionoft hat ex pert willise. enab le a local policy m odule t o decide w het her an associat ed r eser v at ion is ad m in ist r at iv ely perm it t ed ( inclu ded in a pat h or Reader s w ill obt ain r aeser g reat der st anm ding of LAN vater ionun - requ est essage) . and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on ains crem yp tsogr aphic at a tin o clud aut hing en tdet icatailed e t hedescr or iginat in gs,nrev odeiew an dquest ions aI nt b regr oadit ryang e of intCon egrtal sy st and servdices, ipt ion per haps t osion v erifand y t he en t s and of t his r eser v atr ionuest t o en su re con cept comp r eh en r etcont en t ion, ad dit ional esour req ces f ormfuessage. rt her st udy . Cov erag e is also extI send ot only t o newion n etofwor concep t s, wbut old ervat , legacy Scope aned ex nplicit specificat t h keing scop e for for ardalso ing at or eser ion - r eq uest syst em s, pr ovid in g m a essage. m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease prReser odu ctv iv atition y an d imCar pr ov r ies e eff t he iciency, I P ad dr help essing of at he r eceiv r eader er tm h at ake r equest mor e ed in t elligent a con fir,mcost at ion. - effIicient t appear s decisions Con fir matfor iont h eir net in eit w ork h ers.a r eser vat ion - requ est or a r eser v at ion- r equest ack now led gm en t .

Summary RSVP is a t r anspor t layer p rot ocol t hat en ables a net w or k t o pr ovide diff er ent iat ed lev els of ser v ice t o specif ic flow s of d at a. Ost ensibly , diff erent app licat ion t y pes hav e dif ferent per for m ance r eq uir em ent s. RSVP ackn ow ledg es t hese diff er ences and pr ov id es t he m ech anisms •necessar y t o Table of Content s d et ect t he levels of per for m ance r eq uir ed by diff er ent appli- cat ions an d t o m odif y •net w or k behav I ndex ior s t o accom mod at e t hose r equir ed lev els. Ov er t im e, as t im e and lat encyIsen nt e sit rn et k inglicat Te chnologie s ur H ae ndbook , Four th at Edit ivweorapp ions mat and pr olifer e,ion RSVP's cap abilit ies w ill becom e increasingly im Cisco por t ant . By Systems, Inc. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions

•

1:

I s it n ecessar y t o m ig rat e aw ay fr om y our ex ist in g rou t ing pr ot ocol t o su ppor t Table of Content s RSVP?

•

I ndex

I nt e rn et w2or Te chnologie a ndbook , Four th Edit : k ing I dent if y t he tshHree RSVP levels of ion ser v ice,

an d ex plain t he dif fer en ce amon g t hem.

By Cisco Systems, Inc.

3:

What ar e t he t w o RSVP reserv at ion classes, an d how d o t hey d if fer ?

Pub lish er: Cisco Press

4:

What ar e RSVP filt ers?

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 58 705can -1 19 RSVP -2 5 : 1-How

b e used t hr ough net w or k r eg ions t h at d o not supp ort RSVP?

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information • ht t p: / / w w w . iet f .or g / rf c/ rf c220 5. t x t •

Table of Content s

•• ht t p: / / w w w I.ndex cisco.com / un iv er cd / cc/ t d / doc/ cisint w k / it o_d oc/ r sv p. ht m I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 51. Simple Multicast Routing Protocol • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Descr ibe b ack gr ou nd infor m at ion about SMRP.

By Cisco Systems, Inc.

Defin e t he t er m s used in SMRP net w or kin g. Pub lish er: Cisco Press

Descr t heber f unct Pub Dat e: ibe Sep tem 1 1, 2ional 003

ch aract er ist ics of SMRP, inclu ding m anagem ent , t r an sact ion, and

pack m at I SBN:et1-for 58 705 -1.19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction The Sim p le Mu lt icast Rou t in g Pr ot ocol ( SMRP) is a t r anspor t lay er pr ot ocol d ev elop ed t o r out e m ult im ed ia dat a st r eam s ov er AppleTalk net w or ks. I t su ppor t s Ap ple Com p ut er' s Qu ick Tim e Con fer en cing ( QTC) t echn olog y. SMRP pr ovides conn ect ionless, best - ef for t deliv ery of m u lt icast •dat ag r ams and Table of Content s relies on u nder lyin g n et w or k lay er pr ot ocols for ser vices. I n par t icular , SMRP •facilit at es t heI ndex t ran sm ission of dat a fr om a single sour ce t o m u lt ip le dest in at ions. This chap t er Ifocu nt e rn et won or k ting chnologie H a ndbook Four Edit ion operat ion s of SMRP. Figur e 51 - 1 illust r at es a ses he Te fun ct ion als elem ent s , an d th p rot ocol gener alized SMRP By Cisco Systems, Inc.env ir onm ent . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Figu r e 5 1 -1 . A Ge ne r al iz ed SM RP En vi r onm e nt Run s fr om a M ul t icast I SBN: 1- 58 705 -1 19 -2 Gr ou p t o an En dpoin t Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Ianbcr eat ing SMRP, Ap plealbor r ow a num b er of st at egies andailed concep t s ipt f rom ot her pr otquest ocols ions and r oad r ang e of int egr sy st emed s and serv ices, inrclud ing det descr ion s, rev iew tt echnologies. I n d oing y t er ms rwer t ed tad o dit hav e specif ic rmces eanf or in gs inher Appstle' s SMRP o en su re con cept compso, r ehman en sion and et enet adap ion, and ional r esou fu rt udy . env . Table 1- 1ed p r ovides a tsu marnyetof SMRPspecif ict s, t erbut m s also and tdoefold initer ions. These Cov iron eragment e is also ext5end n ot only om new wor k ing concep , legacy tsyst er ms u ovid sed tinhrgou h is chicapt er.ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich emare s, pr a ghout m or e rt ealist pict pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Tab le 5 1 - 1 . SM RP- Specif ic Ter m s a nd D ef in it ions Te rm

D e fin it i on

adj acen t endp oin t

I n relat ion t o a node or an en dpoint , an en dpoint on t he sam e local net w or k, or a node con nect ed t hr oug h a t un nel.

adj acen t nod e

I n relat ion t o a node or an en dpoint , a n ode on t he sam e local net w or k.

child en dpoint

An adj acent endp oin t t o w hich a nod e send s m ult icast dat a.

child node

I n relat ion t o a mem ber n ode of a g r oup, a neighb or nod e far t her f r om t he or ens dpoint . Tablecreat of Content

child por t

I ndex

• •

I n relat ion t o a gr oup, a por t t hat is t he in t er f ace t o on e or m ore ch ild nod es.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

creat The By CiscoorSystems, Inc. endp oin t

end point t hat r eq uest ed creat ion of t he g r oup, an d t he sour ce of dat a for w ar ded t o t h e gr oup .

Pubor lish er: Cisco Press creat node The p r im ar y nod e t hat creat ed t he g rou p. Pub Dat e: Sep tem ber 1 1, 2 003

designat ed An SMRP rou t er t hat has b een desig nat ed as a p rim ar y or secon dar y nod e. I SBN: 1- 58 705 -1 19 -2 nod e Pages: 11 28

dest inat ion t r ee

The sp anning t r ee r oot ed on a local n et w or k w it h pat h s dir ect ed t ow ar d t h e local gr oup .

endp oin t

A n onr out ing sour ce or dest inat ion of m ult icast pack et s.

gr oup A set r ecip t endpallointins, one or a net m ult icast ess. p rov ides cover age of The u pdat ed edit ion of of t he b estien - selling w ork ingaddr r ef erence essent ial an d cu t t ing- edg e t ech nologies. join Term for t he pr ocess of b ecom ing a m em ber of a g rou p. join in g pat h A p at h on t he dest inat ion t r ee for a local net w ork used t o reach a cr eat or node, Con cise ov erand v iewconst s of rt echn ies t ial t dist o n et wor kvect ing or pr ofession als uct edolog u sin g tessen he SMRP ancealgor it hm . at all lev els, f rom nov ice t o ex pert . leave Term for t he pr ocess of r elinquishin g m em bership in a gr ou p. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP local net A shar ed- access d at a link an d it s associat ed n et w or k lay er pr ot ocol. A LAN ight supp ort t m oreologies t han one n et n . et wor k ing and st or age Cov erag e ofmcut t ing edge echn lik elocal opt ical m em b er An en dpoin t t h at is a m em ber of t h e gr oup . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . endp oin t I nmt ern k in g Tech nologies , Four Edt itr ee ionof , isa agrcom em beterw or node A n ode t h at isHand on tbook h e dist rib utt hion ouppr . ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing neighb or nodMast e I nerrelat t os,a con mem ber a g r oup, ad jacenused t n ode h at is heork ing t echnologies. t he ion t er m cep t s, ntode echnof ologies, an dandevices in ttoday ' s on nettw dist rt oibut ionpor t r ee henet gr w oup . g t echn olog ies in t o a LAN/ WAN env ir onm ent . indu st ry . Lear n how incor at eforintt er or kin Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, nod e A r ou t er im p lem ent ing SMRP. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net or kin g tp rof essionals, r egar of ex ise. parwent por I n relat ion t o adless gr oup, t hepert p ort t hat is t he in t erf ace t o t h e par ent node. par ents node I n arelat ionert oun a der mem ber n ode of a gand r oup, t henneigh nod e tcloser t ot h t he Reader w ill obt ain g reat st an ding of LAN WAN et w orbor k ing, p ar icu lar ly e creatand or en dpoint har dw ar e, pr ot ocols, ser v ices. inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions por t A local n et w or k or t unn el in t erf ace on an SMRP r out er . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov ist also ext n otofonly o new n et wor k ing concep t s, hbut also gr t o oup old er , legacy porerag t pareen Theend ad ed dr ess t he t nod e t hat is r espon sib le for andling r equest s. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich ary nodeoperThe onand a local et worfkorr esponsible or crem eatper ing for gr m oup s. w ill incr ease prprofim essionals at e.n ode Tools gu idnelines opt im izing fsyst ance pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient r ev er se p at h The r ev er se of a j oining pat h , a p at h on t he sour ce t r ee for a local net u sed t o decisions for t h eir net w ork s. for w ar d mu lt icast dat a. second ar y nod e

The n ode r eady t o t ak e over f or a disap pear in g p r im ar y nod e.

sour ce t r ee

The sp anning t r ee r oot ed on a local n et w or k w it h pat h s dir ect ed aw ay fr om t h e local net w or k.

spann ing t r ee

A conn ect ed set of pat h s using local net w ork s b et w een all nodes on an int er net w ork , w it h only on e pat h bet w een an y t w o n odes.

t un nel

A p oint - t o- p oin t conn ect ion bet w een nod es on n onadj acen t net w or k s t hr oug h r out er s not imp lem ent ing SMRP.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SMRP Multicast Transport Services SMRP is designed t o enab le rou t er s an d en d st at ions t o ex ch ange m u lt icast p ack et s ov er net w ork lay er p r ot ocols. SMRP pr ov ides t he cap abilit y t o m anag e m ult icast addr ess assign m en t and enables a sing le sou r ce t o sen d dat a ad dr essed t o a uniqu e m ult icast gr oup add ress. Receiv er s •join t h is gr oup Table Content s er est ed in r eceiv in g d at a f or t h is gr oup. I n sup por t of t h ese if tof hey ar e int •fu nct ions, SMRP I ndexinv olves a num b er of ser vices. Th e discussions t hat follow f ocu s on t he k ey Ipr ntocesses e rn et w or kand ing Te chnologie s H atndbook , Four th Edit ion t ech nologies hat enable SMRP serv ices, includ ing addr ess man agem en t , t he MuCisco lt icast Tr ansact By Systems, Inc.ion Prot ocol ( MTP) , n ode m anagem ent , m ult icast r out e man agem en t , dat a for w ar ding , and t op olog y m anagem en t . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

SMRP Multicast Address Management I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

SMRP add ressin g is b ased on t he local n et w or k of a cr eat or endp oint . An SMRP add ress consist s of t w o p ar t s: a 3 - by t e net w or k nu mb er and a 1 - by t e sock et n um ber . Each local net w ork is conf ig ur ed w it h a r ang e of un iq ue net w or k nu m bers. I n net w ork n um ber m app in g, n et w or k n um bers mu st be assign ed t o local n et s for SMRP an d The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of m ust b e un iq ue t h rou ghou t an ent ir e int er net w ork . Each local net can b e assign ed any essent ial an d cu t t ing- edg e t ech nologies. cont igu ous r ang e of 3- by t e n et w or k n um bers. Th e nu mb er of mu lt icast gr oups av ailable f or a local net is t he nu m ber of net w or k num ber s assig ned m u lt ip lied by 2 54. Net w or k nu m bers can be con figur ed ov orercan b se of m apped fr omiest he net w or kt onu mb er kof lyin g nals et wor k lay Con cise v iew t echn olog essen t ial n et wor ingund pr er ofession at all leverels, f rom pr ot ocols. Un ique n et w or k n um ber r anges can be r eser ved for su ppor t ed net w ork pr ot ocols. nov ice t o ex pert . I n t heNew casechapt of mer ults icast addr ess map ping SMRP ult icast addr ust be m app ed t o include cov erag e of im, por t antmt opics like VoIesses P andmEAP net w or k layer m ult icast ad dr esses, and t hese in t u rn ar e m app ed t o dat a lin k layer m ult icast add resses. Fore each et w or k lay er t yp e, a b lock of m ult n icast adkdr esses be obt ained for Cov erag of cutnt ing edge t echn ologies lik e opt ical et wor ing and mu st orstage SMRP. I n t h e best case, t hese addr esses w ill m ap d irect ly. I n m ost cases, a dir ect m appin g is n ot possible, oreCisco t hanSy one SMRP add r ess mwapp ed t of or a single Aut hand oredmby st ems, wm or ult ldwicast ide leader in is net or king t he I n tneretnwor et . k lay er m ult icast add ress. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat The m annet nerwin h ich ult icast add ar and e m app o neten w or k layer ad dr net ork enables or w kin g p rmofessionals t oresses un derst an dedimt plem t cont em por aresses y int erisnet wwork ing lay er - depend en t . Wh layt echn er m ologies, ult icast add d oused not m dir ect net ing w ork t echnologies. Mast er en t heSMRP t er m s,t r anspor con ceptt s, an dresses devices inap t oday ' s ly nett ow ork lay erstm icastn ad dr esses, filt ering h enet SMRP mg ultt echn icast olog addries esses equirWAN ed. Wh enir onm net went or k. indu ryu. ltLear how t o incor por at e of int ter w or kin in t oisa r LAN/ env lay erplet m uelt w icast ad dran esses do not map dir t o dat er opt muical lt icast t he n et y, wor k Com it h new d u pdat ed chapt er sect only secur it ya, link st orlay age, netaddr w or kesses, in g, scalabilit lay is ex pect t o filt ulteicast h ave eent op subscrib . essen t ial t o all anderspeed, t h isedbook isera out comm plet an d addr u p- tesses o- d at et hr at ef er encen tot o tbhe ics t hatedare net w or kin g p rof essionals, r egar dless of ex pert ise. Net w ork lay er m ult icast add resses ar e p reset for AllEndp oin t s, AllNod es, an d AllEnt it ies add resses. point messages t o t his ult icast add ress e kr elay alllar end Reader s w illAllEnd obt ain a gsreat er un dersent st an ding of m LAN and WAN n et ar w or ing, ed p art toicu ly tpoint h e s on a net orar k.e,AllNod es m essag es vsent o tolv his ed m .ult add ar enology r elay ed o all out nod har w dw pr ot ocols, and ser ices tinv Fuicast ndam entress al t ech inft or matSMRP ion is rpr oving ided ones on n et w or k e, and iesstm essages sentices, to th m ult addr ess are all quest en dpoin a ba r oad r ang of intAllEnt egr alitsy em s and serv inisclud ingicast det ailed descr iptrelay ion s,ed revt oiew ionst s and SMRP r out in g n odes onsion a net w or k .en t ion, and ad dit ional r esou r ces f or fu rt her st udy . t o enall su re con cept comp r eh en and r et Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Transaction Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease SMRP Multicast Protocol pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. SMRP inv olves a mu lt icast t ran sact ion pr ot ocol ( MTP) t h at pr ov ides for t hr ee t r ansact ion t y pes: nod e, en dpoint , and sim u lt aneous nod e/ end point . Com m unicat ions b et w een ad jacent nodes and bet w een nod es and en dpoin t s occu rs t hr ough r equest / r espon se t r ansact ion s. Responses alw ays are u nicast . MTP p r ovides f or t he ret r ansm ission of requ est s or responses in case of net w ork er r ors. Only hello and d esignat ed nod e- r equ est packet s ar e sent as m ult icast

m essages; all ot h er s ar e u nicast . End point - t o- node r equest s ar e sen t as mu lt icast s, w hile nod et o- end point requ est s ar e sent as eit h er unicast s or m ult icast s. The b asic MTP d esign as im plement ed in SMRP rou t er s u ses t w o queues f or all t r ansact ions: a r eq uest qu eu e and a r esponse qu eu e. The r equest - qu eu e en t r ies ar e d elet ed af t er t he r ou t er pr ocesses t he r esponse t h at it receiv ed. Th e response is p rocessed, wh en m at ched w it h a r eq uest , using a callback specif ied in t he ent r y . •

Table of Content s Aft er r esponse pr ocessing , t he r equ est is discar ded. I f t h e r eq uest is un answ er ed, an int er nally •gener at ed r eject I ndexr esp onse, w it h t he err or MCNoResponse, is sen t t o t he callback . Request s can Ibe nt esent rn et wtor chnologie H a ndbook th Edites ionor AllEndp oint s m ult icast ad dr ess, depend in g on o kaing unTe icast ad drsess or t o t,hFour e AllNod t heCisco By con Systems, t ex t . Unless Inc. exp licit ly r ed irect ed , r equest s ar e sen t t o t he AllNodes m ult icast .

ThePub r esponsequeue en t ries ar e cr eat ed upon r eceipt of a r equest p ack et . Th e en t r y is r ef er enced lish er: Cisco Press du rin g all pr ocessin g of t h e r eq uest , and t he pr ocessed ent r y r em ains in t h e queue unt il it Pub Dat e: Sep tem ber 1 1, 2 003 exp ires and is d elet ed f r om t he queue. I f a d uplicat e r eq uest is r eceived, it is ign ored if t he SMRP SBN: 1- 58 705 -1 19 -2 r out er Iis st ill pr ocessing t he or igin al r eq uest , or if a d uplicat e r espon se is generat ed if pr ocessing 28 is comPages: plet e.11Respon ses alw ay s ar e un icast t o t he requ est or . Som e r eceiv ed r eq uest s r eq uir e an SMRP r out ing nod e t o g en er at e addit ional requ est s. I n t his case, t he or iginal requ est ( s) will b e pr ocessed b y t he callback han dler of t he r out in g node's requ est en t r y.

The u pdatNode ed edit Management ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of SMRP essent ial an d cu t t ing- edg e t ech nologies. SMRP r elies on a n um ber of node relat ionships, in clud ing desig nat ed nodes, adj acent nod es, an d t un nelCon nod es, ov t oerper m its of t r anspor t of ies mu essen lt icastt ial dattagr s. k ing pr ofession als at all lev els, f rom cise v iew t echn olog o nam et wor nov ice t o ex pert . Desig nat ed nodes ar e SMRP r out er s t hat hav e been sp ecified as pr im ary or second ary n odes. A designat pr imer ary n ode is cov r esp onsible forpor allocat gr ou p ad drPesses. A pr im ary node is Newedchapt s include erag e of im t ant ing t opics like VoI and EAP r eq uir ed f or each local net w or k w it h SMRP n odes. A d esignat ed second ar y node is requ ir ed if a local net or k ehas m ort ing e t han onteechn node. Th e second used main copy of t he Gr oup Covwerag of cut edge ologies lik e optary ical isn et wor kt oing andt ain st ora age Cr eat ion t able, and it b ecom es t he p rim ar y nod e if t he pr im ar y node for a net w or k fails. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The b asic pr ocess of pr im ary and secondar y n ode det er m in at ion b eg ins at st art u p, w h en a node I n tstern et w or in g Tech Hand , Fouryt hn ode Ed it on ion ,each is a local com prnet ehensive refer ence fir t ries t o kbecom e tnologies h e desig nat edbook secondar . I f successfu l, t het hat n ode net or kin g ep trhe ofessionals t o un derst an dTrim en t cont ar yby inteit erher net wa ork ing tenables hen t r ies t owbecom d esign at ed p rim ar yand node. anplem sact ions ar e em in itpor iat ed t echnologies. er t he m s, con cep t s, et echn ologies, d onse devices in t oday ' sicat netes w ork ing pr im ary - n ode Mast r eq uest or taersecond ary - nod r eq uest . No ran esp t o tused he r equest ind t h at st ry . Lear n su how t o incor at ae posit int er net or kin g t echn olog in t tohe a LAN/ ir onmI fent tindu he negot iat ion cceed ed , wpor hile iv e wr esp onse indicat esies t hat negotWAN iat ionenv failed. t w.o Comes plet h new eant he d udpdat edatchapt er saron secur st ordesign age, opt ical net wdar or ky innod g, scalabilit y, e nod t rye w t oitbecom esign ed p rim y nod e it ory ,t he at ed secon e at t he sam t h is wbook is alow com e or ankdlayer u p- t od at e r ef er ence t o t he t opt h ics t hat are essen t ial A t o all tand im e,speed, t he n ode it h t he er plet net w u nicast add ress becomes e desig nat ed node. netim w ary or kin g p rof essionals, r egar dless of t ex ise.s an d r em ove- gr oup ent r y p ack et s t o t he pr node t hen sends addg rou p en ry pert packet second ar y node f or a local net w ork t o m aint ain an id en t ical gr oup creat ion t able. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw arion e, pr and ser vorices olv ed . Fu ndam entnode al t ech mateion is pr ovwided I n relat t oot a ocols, sp ecific n ode en inv dpoint , an adjacent ex nology ist s on inf t heorsam local net ork . on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest Nodes per iodically send out hello pack et s on each por t . I f a h ello packet is not receiv ed f r om ions an tadj o en su re conecept comp r eh ain en sion and et en and ade'dit r esou r ces or ch fuanged rt her stt oudy . acen t nod w it hin a cert int er v al rof t imt ion, e, t he nod s ional adj acen cy st at e f is n ot Cov e is also ext end ededn rotout only t oenew et wor ing concep t s, ify butp ack alsoettso ar old , legacy opererag at ional, and associat es ar m arkn ed unrkeach able. Not e er sen t t o each syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm s in wsthich adj acen t nod e w henever t he st at e of a por t in t he n ode chan ges t o a dif ferent operent at ional at e. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr Each node main t ains an ent r y in t he nod e t able f or each ad jacent n ode. The t able ent r yease is pr odu cted iv itt he y an pr eovt e effiticiency, help ing t he eader m ake mor e inTab t elligent - eff icient allocat firdstim t im hat r eceiv es a pack et frrom adjacent node. le en t, r cost ies includ e t he decisions for t h eir net w ork s. t im e of t he m ost recen t h ello packet and it s st at e. Tun nel nod es ar e p oint - t o- p oin t conn ect ions bet w een nodes on non adj acent net w or ks t hr ough r out er s not imp lem ent ing SMRP. Tw o d ist inct t unn el nodes ar e d ef ined: t unnels b et w een n odes, and t u nnels bet w een a node an d an end point .

Tun nel nod es ar e m aint ain ed as ent r ies in t he adj acen t n ode t ab le in ev er y nod e in t he sam e w ay as f or ot her ad jacent n odes w it h respect t o t he u se of h ello packet s an d n ot ify p ack et s. Sim ilar ly , SMRP en ables t un nel nod es t o join and leave gr oups in t h e sam e m an ner as any ot her adj acen t nod e.

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NO TE Table of Content s I ndex

I nt e rnCisco et w or kdoes ing Tenchnologie s Hta tndbook th Edit ion er , ot sup por u nnel , nFour odes. Howev By Cisco laySystems, er t unn els Inc.b et w een

SMRP can be enab led t o ru n net w ork

n onadj acen t nod es.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 SMRP Multicast Routes Pages: 11 28

SMRP r elies on a span ning t r ee- based for w ar ding sch em e t o det erm ine rou t ing pat hs for m ult icast t r aff ic. This r out e- det er minat ion p rocess relies on t he use of a dist ance- v ect or algor it hm . A node send s dist ance- vect or r eq uest pack et s t o ad jacent nodes at st ar t u p t im e an d w hen rou t es ch ange. Th e dist ance specif ied in t he v ect or is t he n um ber of hop s needed t o r each a p arutpdat icu lar w ion ork of num r ang e. Nodes con t ainnet aw v ect entpr rov y inides t he cover net w ork The ednet edit t heber b est - selling all- inone orkor ingf or r efeach erence age rou of t e tessent able an d send as m any packet s as n ecessar y t o sen d all t he v ect or s. Wh en r out es chang e, each ial an d cu t t ing- edg e t ech nologies. nod e sen ds dist ance- v ect or r equest p ack et s t o ev ery adjacent node. WhenCon a r out is er r eceiv a por t , ties he essen por t - pt arent ress m ust b e set for r outlev e els, for all cisee ov v iew ed s ofon t echn olog ial t o nadd et wor k ing pr ofession alst he at all f rom por t s.nov Because t he g rou ice t o ex pert . p addr ess is boun d t o t he net w ork ad dr ess, t h e por t - par ent addr ess also is used if a node is t o h andle a requ est for sp ecified gr oups. Wh en t h e por t - par ent addr ess is t he s include cov erag e of sib im por t ant like. VoI and nod e' New s ow nchapt addrer ess, t he nod e is r espon le for t h teopics r eq uest EquPalpatEAP h nod es d ecide wh ich nod e is r espon sib le for a requ est by d et er m in ing w hich n ode has t he h ig hest net w or k add ress. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age When a d ist an ce- v ect or requ est w it h ent r ies for unk now n local net w or ks is receiv ed b y a n ode, Aut ored by Sy sted ems, w or ldw ide in ed nett ow or king I n teertnable et . for t he n ode, net w or k hr anges f orCisco associat local n et wor k sleader ar e add t he n etfworortkher out w it h a r eceived dist ance incr em ent ed by 1 . The ad jacent node t h at sent t he d ist an ce- v ect or Ipack n t ern or kbecomes in g Tech nologies Hand book t h Ednet it ion is .aTh com ehensive ence etett w hen t h e par ent node f or, Four t h e local w ,ork e tpr able ent r y isrefer u pdat ed tifhat a enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net ork ing dist ance- vect or p ack et is r eceiv ed f or k now n local n et wor k s, and if t he d ist an ce- v ect or wpacket tplus echnologies. connod cepet s, t echn ologies, devices in at oday ' s cenetvwect ork 1 is less tMast han er t h et he en tt rer ym ins,t he r out e t ab le. A t ieanbrd eaker is uused sed if d ist an oring indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm pack et is r eceived fr om an ad jacen t n ode w it h t he sam e dist ance t o a local n et w or k . The t ieent . Com plet e an dt ou be pdat ed adj chapt ertsnon st or age, net wuornicast k in g, addr scalabilit br eaker is wd it ethernew m ined t he acen odesecur w it hit ya , hig her netopt w orical k layer ess. y, That and speed, t h is book is a com plet e an d u pt od at e r ef er ence t o t he t op ics t hat are essen t ial t o all nod e is ident ified as t he par en t n ode f or t he local n et w or k . net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e SMRP Group Management har dw ar e,Multicast pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tI on en su re m con and et en t ion, ed andv ia adadit r ces f n oregfuotrtiat her st udy SMRP, ultcept icastcomp g rourpehpen ar tsion icipat ion r is m anag prional ocessr esou inv olving ions am.ong Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy endp oin t s and n odes. An end point at t emp t s t o join a g rou p b y cont act ing a n ode on a local syst s, Any pr ovid in gact a ed m ornode e r ealist ic pict ur e of realor lddist n et w orion k ingt r en s inp w net wem or k. cont is r esponsible f ort he join in g wt he r ibut ee vir foronm t heent gr ou b yhich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease act ivat in g p at hs t o an ex ist ing dist r ib ut ion t r ee. Nod es leav e a d ist r ibu t ion t r ee for a g rou p b y pr oduivat ct ivin it yg an imwprhov ingber t heendp r eader in tpelligent , cost - eff picient deact p atdhs eneeveff ericiency, no mor help e m em oin tm s ake f or tmor he gerou ex ist on t hose at hs. decisions for t h eir net w ork s. Four b asic p rocesses ar e r eq uir ed t o m anage SMRP g rou ps: cr eat in g, j oining, leav ing, and delet in g. An en dpoin t sends a creat e- gr oup r equest t o t he d esign at ed p rim ar y node w hen it w ant s t o st art sen ding dat a t o a gr oup . The p r im ar y nod e t hen assign s an unu sed gr oup add r ess and allocat es an en t r y in t he gr oup cr eat ion t ab le. Th e pr im ary node f inally r et u rn s t he gr oup addr ess t o t he

creat or en dpoint and sen ds an add - gr oup r eq uest t o t he secon dar y nod e, if it ex ist s. En dpoint s send r equest s t o init iat e join in g a m ult icast gr oup . The p ar en t nod e for a gr ou p on a local net w or k r espon ds t o en dpoin t –join - gr oup r eq uest pack et s. ( A nod e det erm ines w het h er it is t he par en t n ode by ex am ining t he n et wor k n um ber in t he g rou p ad dr ess. ) Wh en t h e par ent node for a g rou p g et s a j oin- gr oup r equest p ack et an d t h at n ode is n ot y et a mem ber of t he gr oup, t he node f or w ard s t he j oin requ est t ow ard t h e cr eat or n ode of t he gr oup. Ev en t ually t he joingr oup r equest p ack et r each es a m emb er node or t he cr eat or node for t h e gr oup , and a join• Table of Content s gr oup conf irm packet is sent back along t h e rev erse pat h. Th e mem ber or cr eat or nod e adds a • I ndex child por t t o t he g rou p for w ard ing t able if t he join w as r eceiv ed on t hat p or t . When dat a ar riv es I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion in t he r ever se pat h, it is f orw ar ded t o all ch ild por t s. Wh en t h e creat or n ode r eceiv es t he f ir st By Cisco Systems, join r equest f or Inc. a g rou p, it for w ar ds t h e r eq uest t o t he cr eat or en dpoint t o en able it t o st ar t sen ding dat a. Pub lish er: Cisco Press

To leav e a m ult icast g rou p, end point s send leav e- gr oup r equest pack et s on t heir local net . The Pub Dat e: Sep tem ber 1 1, 2 003 par ent node f or t h e gr oup on a local net r et u rn s a leav e- g rou p con fir m pack et t o t he endp oint I SBN: 1- 58 705 -1 19 -2 and sends ou t a gr oup- mem ber r equest pack et on t he ch ild por t . I f t h e par ent node d oes not g et Pages: 11 28 a g r oupm em ber confir m p ack et on t he ch ild por t fr om a m em ber n ode or end point , t he par ent nod e r em ov es t hat por t f r om t he ent ry . I f t he par en t n ode has no child por t s left in t he ent r y , it set s t he st at e of t he ent r y t o leav ing and sen ds a leav e- gr oup r eq uest pack et up t he dist rib ut ion t r ee t o it s p ar en t nod e. Each respect iv e p arent nod e r em ov es t he ent r y f rom it s gr oup for w ar ding t ab le wh en it receiv es t he leav e- gr oup con fir m pack et . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of The end a edg delet gr oup r equest w hen it w an t s t o st op sending dat a t o t he g rou p. essent ialpoint an d sen cu t tds inge et ech nologies. On ly t he designat ed pr im ary node r espond s t o t h is r eq uest . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Forwarding Multicast Datagrams

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP SMRP dat a for w ar ding inv olves n odes for w ar ding m ult icast dat ag ram s on act iv e pat hs of t he Cov erag cuttticu inglar edge t echn e hopt icalmnem et wor ingpoint and sston or age sour ce t r ee f ore aof par gr oup. Anologies act iv e lik pat h as ber kend it for t he gr oup , or it is a pat h need ed as a t r ansit p at h t o r each ot h er act iv e pat h s. The sub set of act iv e pat h s for t he Aut ored by dist Cisco Syion st ems, or ldw leader or der t he SMRP I n t er ninv et .olves a ser ies sour ce t rhee is t he r ibut t r eewfor t heide gr oup . Datina net for w w or ar king ding fun of negot iat ion s am ong en dpoint s and nod es. I n gener al, nodes r eceiv e mu lt icast dat agr am s Iwnhen t ern en et wdpoint or k in g Tech t h or Edend it ionpoint , is acan comsend pr ehensive refersence s sen d nologies d at a t o aHand g roubook p. Th, eFour creat dat a packet w it ht hat a enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w or k layer m ult icast ad dr ess t o it s local net w or k aft er it r eceives a join requ est frnet omw ork t h eing tcreat echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ingt o or node. Par ent n odes on t he local n et w or k r eceiv e t his m ult icast and f or war d t he packet indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm all child por t s in t he f or war d in g t able for t he g rou p. A node m u lt icast s a packet on a local ent . Com w it hif new u pdat chapt it y ,t hat st orlocal age, net opt w ical w orifktin net wplet or k eonly it is an t hed par ented node forert sh eongrsecur oup on or knet and heg,dscalabilit at a w as y, and speed, t h is book is a com plet e an d u pt od at e r ef er ence t o t he t op ics t hat are essen t ial t tohat all r eceived on t he p arent por t for t h e gr oup . Nodes also f orw ar d dat a t o ad jacen t t unnel n odes net w or kin g p rof essionals, r egar dless of ex pert ise. ar e m em b er s of t h e gr oup. I n t h e case of an SMRP t u nnel, m ult icast dat ag r ams are encapsu lat ed in a un icast net w ork lay er pack et . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Handling Topology Changes t o en su re conSMRP cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in ge amm or ained e r ealist pict urent e ofit ies t he t o realw age or ld pat n ethw or km ing virsh onm ent s ges in wwhich Topology map s ar aint byicSMRP m an emen ber ip chan it hin pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease an SMRP en vir onm ent . SMRP an t icip at es a nu m ber of t y pical t opology ch anges and def in es pr odu ic ct iv it y niques an d im fpr e eff iciency, specif t ech orovhan dling t hemhelp . ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Disappearing Member Endpoints To d et ect disap pear in g mem ber endp oint s, nod es p er iodically sen d a gr oup - mem ber r equest pack et t o each act iv e child por t . Each m emb er node an d en dpoint r et ur ns a gr oup- m em ber

conf ir m at ion packet t o t h e par ent node. I f no gr oup- m em ber conf ir m at ion packet s ar e r eceiv ed by t he par ent node, t h e nod e send s a leav e- g r oup requ est packet t o it s p ar en t nod e and t h en delet es t he gr ou p ent r y .

Stranded Groups •To d et ect st r an Table dedof gContent rou ps,s cr eat or nodes per iodically send a g rou p- cr eat or requ est pack et t o t he •creat or en dpoint I ndex. I f af t er a n um ber of r et ries no gr oup - cr eat or conf irm packet s ar e r eceiv ed by It he nt e rn w or s Hpa ndbook FourNet th Edit ion cret eat ork ing nodTee,chnologie t he g rou is delet, ed. w or k r out e t ab les are k ept up- t o- dat e b y nodes sen ding dist ancevect or p ack et s t o t heir adj acent nod es w h en r out es chan ge. This allow s nod es By Cisco Systems, Inc. t o ch ange m u lt icast g rou p rou t ing based on chang es in t op ology . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SMRP Transaction Example A t yp ical SMRP- based t ran sact ion session in volv es a Macint osh w ork st at ion cr eat ing a g r oup, ot her Macint osh w or kst at ion s joinin g t h e gr oup , and dat a being sen t t o t he g r oup mem ber s. •I n a t y pical SMRP Table of t r Content ansact sion session, a Macint osh ( call t his sy st em Cr eat or - Mac) fir st sen ds a •creat e- gr oupI ndex r equest t o all nod es on a par t icular net w or k. The p rim ar y r out er ( Pr imar y ) f or t h e Ilocal nt e rn net et w w oror k ing Te chnologie H a ndbook Four th Edit ion and r et ur ns t h at ad dr ess t o t he Cr eat or - Mac. A k assign s an sunu sed gr, oup add ress Macint osh on a dist ant net w or k ( called Memb er - Mac) find s t he Cr eat or - Mac via t he Nam eBy Cisco Systems, Inc. Bindin g Pr ot ocol ( NBP) . Pub lish er: Cisco Press Cr eat or - Mac t h en r espon ds w it h t he gr oup addr ess via an NBP r espon se. Th e Mem ber- Mac sen ds Pub g Dat e: p Sep tem ber 1 t1,o2all 003n odes. A r em ot e rou t er ( say , Rout er M) w it h a v alid r out e t o t he a j oinrou r equest I SBN: 158 705 -1 19 -2 gr oup an d a corr ect por t par en t sends a j oin - gr oup r eq uest t ow ar d t he Pr im ary . Pages: 11 28

The Pr im ar y finally r eceiv es t he j oin - gr oup r eq uest and sends it t o t he Cr eat or - Mac. I t also ad ds t he in com ing p ort t o t he gr ou p in t he for w ard ing t able. The Creat or - Mac con fir ms t he j oin- gr oup r eq uest and sends d at a t o t he gr oup. The Pr imar y r eceiv es t he d at a and f orw ar ds it t o t he gr oup 's child por t s. The u pdat edit ionr eceived of t he b by est Rout - selling all-winonelook netswup orkting erence covertage Finally, t heeddat a is er M, h ich he gr ef r oup in t hperov forides w ar ding ab leofand essent ial an d cu t t ingedg e t ech nologies. for w ar ds t he m ult icast dat a. The Mem ber - Mac t h en r eceives d at a f or t he g r oup. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

SMRP Packet Format Figur e 51 - 2 illust r at es t he general SMRP packet for m at .

• •

Table of Content s I ndex Figu r e 5 1 -2 . A Ge ne r al SM RP Pa ck e t Consist s of Fi ve Fie lds

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The in gedit d escr ar ize t he ackw etork f ields r at edpin 51 - 2: The fuollow pdat ed ionipt ofions t he sum b estm - selling all-SMRP in- onep net ing rillust ef erence rovFigur ides ecover age of essent ial an d cu t t ing- edg e t ech nologies. P rot ocol ve rsion — I n dicat es t he v ersion of SMRP. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Ty novpe ice—t oConsist ex perts. of t w o sub field s. The f irst 2 b it s m odify t he pack et t y pe specified b y t he bot t om 6 bit s t o ident ify w h et h er a p ack et is a t r ansact ion pack et and , if so, w hat t yp e of tNew r ansact ion. chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Se nce mtber Mattches r espon ses r eq uest s wor in t rkansact ions t oage av oid d uplicat e Covque erag e ofnu cut ing — edge echn ologies lik et oopt ical n et ing and st or r eq uest s and r espon ses. All p ack et t y pes ar e t r ansact ion packet s an d w ill h ave a non zer o seq nu mb er (Sy w itsthems, t h e except m ult icast dat a king packet s w h ose Aut huence ored by Cisco w or ldwion ideofleader in net w or f ors an t hed Ihnello t er npacket et . seq uence nu mb er s ar e set t o zero) . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Group Ser v es as t toheundderst esignand at edanprdim y node assign resses enables net waorddr kiness— g p r ofessionals imarplem en t and cont em por sargr y oup int eradd net w ork ingf or all m ult icast cest er onmts, h econ local or k. ologies, A par t icular net used w or k in can b e assig ming or e t echnologies. Mastsour er t he cepnet t s, wt echn an d local devices t oday ' s netned w ork on ennet w ork num ber mer ultnet ip le net wgork numolog beries s min ust in a WAN cont igu r ang e.. indu stt han ry . Lear how t o incor por,atbu e tint w or kin t echn t o baeLAN/ envous ir onm ent Nodes con n eted wor k n um t hat ar ue t oopt each and eachy, Com plet e w itmhust new anfigu d ure pdat chapt er sber ons secur it ye, uniq st or age, icallocal net wnet or kwinork g, scalabilit pr im ary node t o ispraevent collisions ultdicast aderdrence esses. pr im aryare node assigns and speed, t h is book com plet e an d uofp-m t oat e r ef t o When t he t opaics t hat essen t ial t oaall new p essionals, addr ess, itr egar ar bitdless r arilyofassig ns an net w or kin g rou p rof ex pert ise.y unu sed gr oup add r ess f or it s net w or k nu mb er . D as twa— Varies ingunon SMRP p ackof et LAN t y pe.and Table 5 1-n 2et su mm ar izes Reader ill obt ain adepend g reat er der st an ding WAN w or k ing, p ar dat t icualarchlyaract t h e er ist ics p ack etand t y pe. har dwbased ar e, pron ot ocols, ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Tab leat5e.1Tools - 2 . Da ar a ct i stimics B ased e t Type pr of essionals oper andt aguCh id elines f oreropt izing syst emon per Pack for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

• •

Pack e t Ty pe

D a t a Ca rr ie d

Si ze

Mu lt icast d at a

Dat a

Var iable, depending on net w or k lay er d at agr am size

Hello

Por t st at e

2 by t es

Not ify

Por t st at e

1 by t e

Table of Content s

Desig nat ed None I ndex nod e

0 by t es

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Dist ance v ect orInc.Mu lt icast By Cisco Systems, Cr eat e gr oup

v ect or

None

8 by t es 0 by t es

Pub lish er: Cisco Press

Delet e gr oup None Pub Dat e: Sep tem ber 1 1, 2 003

0 by t es

-1 19 -2 Join grI SBN: oup 1- 58 705None

0 by t es

Pages: 11 28

Add gr oup ent r y

Net w ork lay er un icast add ress

Var iable, depending on net w or k lay er ad dr ess for m at

Rem ove gr oup

None

0 by t es

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent d cu t t ingedg e t ech nologies. Leav eial gr an oup None 0 by t es Cr eat or None 0 by t es Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom r eq uest nov ice t o ex pert . Mem ber None 0 by t es r eq uest New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Reject indedge icat ion Shor t inical t eger anging rom st –77 00 t o – 771 0, Cov erag e of Er cutr or t ing t echn ologies lik e opt n etrwor k ing f and or age depend in g on er r ors Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: •

Descr ibe t he SMRP add ress. Table of Content s

I ndex What t y pe of m essag e is sent w hen an en dpoint - t o- node requ est is mad e? What I nt e rn et w or kt y ing s H aisndbook Four Edit ion peTeofchnologie m essage sent ,for a th n odet o- en dpoin t ? •

2:

By Cisco Systems, Inc.

3:

How d oes a nod e becom e t he designat ed pr im ary n ode on a net w ork ?

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Part VIII: Network Management Ch apt er 52 Secur it y Tech nologies • •

Ch apt er 53 D irect or y- Enabled Net w or k ing Table of Content s

Ch apt er 54 Net w or k Caching Technologies I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Ch apt er 55 St orag e Net wor k ing

By Cisco Systems, Inc.

Ch apt er 56 I BM Net wor k Managem en t

Cher: aptCisco er 57 Rem ot e Pub lish Press

Monit or ing

Pub Ch Datapt e: Sep 1 1,ple 2 003 er tem 58ber Sim Net w or k

Manag em ent Pr ot ocol

I SBN: 1- 58 705 -1 19 -2

Ch apt er 59 Qualit y of Serv ice Net w or k ing

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 52. Security Technologies Obj e ct i ve s • •

Table of Content s

Descr ibe t he need for n et w or k secu rit y . I ndex

I nt e rn Ietdent w or kifing Te chnologie a ndbook th eat Editsion y and ex plains tHhe secur, itFour y t hr posed

t o n et w or k s.

By Cisco Systems, Inc.

Discuss t he im por t an ce of a secur it y policy and it s r elat ionship t o net w or k secu rit y . Pub lish er: Cisco Press

Descr ibe a defense- in- dept h secu r it y solu t ion.

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: ibe 1- 58h705 Descr ow-1t19 o -2m it ig at e t he var ious t h r eat s against a net w or k. Pages: 11 28

I dent if y t he t ools u sed t o im p rov e net w or k secur it y . The I n t er net has ev olv ed fr om a net w ork sim ply u sed t o t r an sf er files t o a net w or k t hat is used t o pur chase aut om obiles, fill p rescript ion s, apply f or hom e loan s, and pay bills. Com pan ies h ave r ealized t hat t o eff ect iv ely use t he n et wor k t o condu ct bu siness, t hey m ust secur e t heir net w or k s. The u pdat ed sedit of t he b estized - selling in-tone w ork r efals' erence p rovwh ides Gov ern ment havion e also r ecogn t h e allneed o pr net ot ect inding iv idu pr iv acy en cover t h eir age of essent ial an d cu t t ingedg e t ech nologies. inf orm at ion is used by t hir d par t ies, su ch as h osp it als and finan cial in st it ut ions. This chap t er discu sses t he t hr eat s posed t o net w or ks and t he p rin ciples of a defense- in - dept h Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom secur it y solut ion w hen mit ig at ing t hese t hr eat s. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Why Is Network Security Important? Com pu t er net w or ks g ive com pan ies an d in divid uals dif ferent benef it s and oppor t u nit ies. An online b ook comp any r elies on t h e availabilit y of t h e I n t ern et t o allow cu st om er s fr om an yw h er e in t he w or ld t o pu r ch ase a book an yt im e. A st u dent in Sou t h Am er ica depends on an Aust r alian •e- lear nin g com Table of Content pany ' s ser v ser s t o comp let e t he cour ses requ ired t o ob t ain h is t ech nical pr odu ct •t r aining . Ult im I ndex at ely, t he im por t ance of n et w or k secu rit y d ep en ds on t h e perspect iv e of bot h t he Ipr ntov e rnider et w or k ingend Te chnologie and user . s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

This sect ion f ocu ses on t h e follow ing fact or s t hat of t en dict at e t he need for n et w or k secu rit y : Pub lish er: Cisco Press Pub ber 1 1,et2 003 GrDat owe:t hSepoftem I nt ern app licat ions I SBN: 1- 58 705 -1 19 -2

Fast er 11 I n28t er net access Pages: Gov ern ment legislat ion I nt er net ap plicat ion s hav e evolv ed f r om e- mail t o st r eam ing v ideo and on lin e bank ing . The int r odu ct ion of t h ese new ap plicat ion s has cr eat ed n ew avenu es for t h e hack in g com m unit y t o The uifpdat ed exp editloit ion new of t he b estabilit - selling in- one net w ork ing r efclud erence rov ides coverorage ident y and v ulner ies. allTh ese v ulner abilit ies in e r evpealin g passw ds, of essent ialaan d upt cu t tion ing-of edg e tice, ech nologies. causing d isr serv and obt aining u naut h orized access t o sy st em resour ces. Wit h fast er I nt er net access f or hom e u ser s w it h Digit al Su bscr iber Lin e ( DSL) and cable Con cise ov of has t echn ies t ialndar t o nies. et wor k ing ofession at all lev t echnologies, t heerIvniew t er snet exolog pand edessen it s bou Now t hepraver age als h ome u ser 'sels, PCsf rom ar e nov ice t o ex pert . m or e su scept ible t o at t ack s t y pically lau nched ag ainst cor por at e com put er s because t hey ar e " alw ays on. " I n add it ion , fast er I nt er net access h as helped com pan ies in cr ease pr oduct iv it y by New chapt er sem include covt oerag e offr om im por t ant opics likeer' VoI P and encour aging t h eir ploy ees w ork hom e. tThe w ork s hom e nEAP et wor k ex t en ds t h e com pany 's net w ork b ound ar ies ou t sid e t he com pany ' s w alls. As a r esu lt , t he com pan y faces Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age add it ion al t h reat s. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Gov ern ment s hav e r ecogn ized t h e imp ort ance of net w ork secur it y and t h e role it play s in bu t ries' infr astHand r uct urbook e, such ast ht r Ed anspor w atprerehensive sy st em s,refer emer gency I n tsin erness et wand or k incoun g Tech nologies , Four it ion t, at ision, a com ence t hat renables espon senet syw stor ems, an d t he m ilit ary . As a r esult , legislat ion has been in t r oduced—and kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing passed —r eq uirMast in g er t hat e net or tkechn secuologies, rit y m easur be im used plement For ex am ple, t echnologies. t heappr t er opr m s,iat con cepwt s, an d es devices in ted. oday ' s net w ork ingin tindu he U. S. , t he Healt h I nf orm at ion Pr iv acy Pr ot ect ion Act ( HI PPA) requ ires t h at h ealt h care st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . pr ov plet iders a pan atdien t 's hed ealtchapt h r ecor e Eur ean Union ( EU) t he EU y, Com e pr w itothect new u pdat er sds. onTh secur it yop , st or age, opt ical has net wen oract k ined g, scalabilit Dir ect iv e on Dat a Prot ect ion, wh ich out lin es h ow per sonal d at a is pr ot ect ed. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Security Threats As net w or k s ev olv e and new t echnolog ies em erg e, so do t he t h reat s p osed t o n et wor k s. En t ire book s h ave b een w rit t en on t hese v arious t hr eat s. This sect ion discu sses t h e m ost comm on: • •

Table of Content s

Unaut h orized I ndex access

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Weak aut h en t icat ion

By Cisco Systems, Inc.

Passw or ds Pub lish er: Cisco Press

Packet sntem iff er s 1 1, 2 003 Pub Dat e: Sep ber I SBN: 1- 58 705 -1 19 -2

App licat ion layer at t ack s Pages: 11 28

Vir uses, w or m s, and Tr ojan hor ses I P spoof ing serion vice The uDenial pdat edofedit of ( tDoS) he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Unauthorized Access Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing

pr ofession als at all lev els, f rom nov ice t o ex pert . This b road t h reat en com p asses t he u se of any sy st em w it hou t t he ow ner 's consent . This act can r angeNew fr omchapt a con or wh cov o u erag ses ae com pan n ett w or k tlike o ruVoI n aPmand ult iuser ertsract include of im pory'tsant opics EAP online g am e ser v er t o a h acker accessing a hom e u ser 's PC an d r et r iev ing per son al f iles. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in Weak Authentication

net w or king f or t he I n t er n et .

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat This t h r eat st em t hat t o does not rand eq uir en t icat orem t h at ses aneraut hw enork t icat enables net includes w or kin g pa r sy ofessionals un derst ane daut imhplem en tion cont poruar y int net ingion m ech anism t hat pr ovid es lit t le or no secur it y benefit . An ex amp le of w eak au t hent icat ion is t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w orkaing w eb st apryplicat t h at tallow s any u ser w it ies h out r eq uirWAN in g aut icat ion. indu . Learion n how o incor por at e intt o er add net wuser or kinaccount g t echnsolog in tfir o st a LAN/ envhent ir onm ent as a sy st em adm inist r at or. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e NO TE har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions sy st emscomp hav er eh st ron g auand t hentr et icat mechan howr esou ev er ,r ces t heyf oroftfuen ar e st not t o enMan su rey con cept en sion enion t ion, and adism dit s; ional rt her udy . im plem Cov erag e is ent alsoed. ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Passwords Passw or ds are oft en a net w or k 's f irst lin e of defense. Passw or ds are u sed t o aut hent icat e an d aut h or ize user s. At t ack er s of t en r ely on t he f act t hat user s assign w eak passwor d s and use t h e sam e passw or d on mu lt iple syst em s.

Sy st em s gener at e p assw or d h ash es based on an algor it hm , such as MD5 . A u ser ent er s a passw ord t h at is h ash ed by t he sy st em . Th is is t he p assw or d t hat h ack er s at t em pt t o cr ack . Weak passw ord s can easily be cr ack ed u sin g p assw or d- cr ack ing t ools. Passw or d- cr ackin g t ools u se t w o com mon m et hod s t o cr ack passw or ds: br ut e- for ce and dict ionar y . The b ru t e- for ce m et h od u ses ev er y com binat ion of let t ers, n um bers, an d sp ecial char act er s t o gener at e t he passw or d hash. Th e dict ionar y passw ord - cr ack in g met hod u ses a list of w or ds t o generat e t he p assw or d hash. Bot h m et hods com par e t h e passw ord hash t o t he • Table of Content s syst em - gener at ed hash . I f t he hashes m at ch, t he p assw or d h as been id en t ified. •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Packet Sniffers Pub lish er: Cisco Press

Packet sn if fer s, also called net w or k snif fer s, ar e soft war e ap plicat ion s t hat capt ur e n et w or k Pub Dat e: Sep tem ber 1 1, 2 003 pack et s off t h e w ir e. I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

NO TE Packet sn iff er s capt u re t raf fic t hat ex ist s on t he sam e br oadcast d omain . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Net w ork if fer ally olog usedies t o essen p er fort ial m ttraf an alysis t oofession id en t ify als n etat w or b andw h Con sn cise ovserwvere iew gs en of er t echn o nfic et wor k ing pr allk lev els, fidt rom r eq uirnov em ice ent st oan d net w ork pr oblem s. Th e hacker com m unit y d ev eloped p ack et snif fer s t o cap t ur e ex pert . pack et s t hat had sen sit iv e inf orm at ion, su ch as p assw or ds, w it h t he g oal of using t his inf ormNew at ion t o gain unaut hor ized access t opor sy tst ems. Th ese t y pically chapt er s include cov erag e of im ant t opics likesnif VoIfer P sand EAP capt u r e only pack et s w it h session s associat ed w it h pr ot ocols and app licat ions in w h ich passw ord s ar e requ ired ( such as Telnet , FTP, HTTP, an dedge POP) t. echn ologies lik e opt ical n et wor k ing and st or age Cov erag e of cut t ing Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

Application I n t ern et w or k in g Layer Tech nologies Hand book , Four t h

Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing App licat ion layer ater t ack t o cep lever w eak nesses he ap plicat soft war e w ork ing t echnologies. Mast t hes tat ert em m s,ptcon t s,age t echn ologies, anin d tdevices usedion in'st oday ' s net im plem ent at ion . The m ost com m on w eak nesses associat ed w it h ap plicat ion s ar e bu ff indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env er ir onm ent . ov er fplet low es. wAit buf fer ov ised t h chapt e result ing titoyst ore m or eopt d atical a innet aw b uff han has been Com h new anerf d ulow pdat er sofont rysecur , st or age, or kerin tg, scalabilit y, allocat ed . Buf fer ov er f low s t yp ically pr ov ide an at t ack er w it h a mechanism t o execut e m aliciou and speed, t h is book is a com plet e an d u p- t o- d e r ef ence t o t he t op ics t hat are essen t ial t o sall code w kin it h gadm inist r at or- orr egar r ootdless - levelofp riv net w or p rof essionals, ex ileg pertes. ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o enNO su reTE con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Alep t h e Sticack Pr of w it ,orex buk ff er en over in s in w hich syst em s, hprOne's, ovid in gSm a ash m orinegr ealist pictfor ur eFun of tan hed realldplains n et w or ing virflow onmsent t echnical oper det ail. pr of essionals at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Viruses, Worms, and Trojan Horses Av ir us is a hidd en , self - r ep licat ing sect ion of comp ut er soft w ar e, usually m aliciou s logic, t hat pr opag at es by inf ect in g ( in ser t ing a copy of it self in t o an d b ecom ing par t of) anot her p rog r am. A

v iru s cannot r un by it self ; it r eq uires t h at it s host p rog ram be r un t o mak e t h e v ir us act iv e. Vir uses ar e com m only spr ead t h r ough e- m ail at t achm en t s, such as gr aphic im ages, w or d pr ocessing docum ent s, and d at a spr eadsheet s. The v iru s is emb ed ded in t h ese at t achm ent s an d inf ect s t h e syst em w hen t he u ser lau nches or execut es t h e at t achm en t . Exam ples of v iru ses include Melissa, BugBear , and Klez. Aw or m is a com put er p rog ram t hat can r un ind ep en dent ly or t h at can pr opag at e a com plet e w or king v ersion of it self ont o ot her host s on a net w or k. I t can consum e com pu t er resour ces • Table of Content s dest r uct ively. Many consider a w orm t o b e su bset of a vir us. Ant iv ir us v endor s, for ex am ple, • I ndex include wor m s in t heir v iru s dat ab ases. Ex am ples of w orm s in clud e Nimd a, Cod eRed , Slapper , I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion and Slam m er . By Cisco Systems, Inc.

ATr ojan hor se is a com put er p rog ram t hat appear s t o hav e a u sefu l f unct ion, b ut t hat also has a hiddPub enlish aner:d Cisco p ot ent ially malicious f unct ion t hat evad es secur it y m echan ism s, somet im es by Press exp Pub loit in g legit im at e aut hor izat ions of a sy st em en t it y t hat inv okes t h e pr ogr am . Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

IP Spoofing An I P spoof in g at t ack occur s w h en a h acker inside or out side a net w ork p r et end s t o b e a t ru st ed com put er . The h acker can do t his in one of t w o w ay s. He uses eit her an I P add ress t hat is w it hin tThe he ran ge ed of tedit r ustion ed of I P tadd f or a alln et inworone k ornet anwau t r ust ed exides t er nal I P ad dr ess u pdat he bresses est - selling orkt hor ingized, r ef erence p rov cover age of t o w hich access is pr ovid ed t o sp ecified resour ces on a net w or k. I P spoofing at t ack s ar e of t en a essent ial an d cu t t ing- edg e t ech nologies. launch point f or ot her at t ack s. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice o ex pert . Denial of tService New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Denial of ser vice ( DoS) at t acks are perh aps m ost f ear ed becau se dow nt im e m ean s lost r evenu e. The gCov oal erag of a eDoS at ttack t o disr uptologies or lim itliklegit imat s' kaccess of cut ing is edge t echn e opt icalenuser et wor ing andt ostaorr esou age rce. A sim ple for m of a DoS at t ack can b e cau sed by a br ut e- f orce p assw or d at t ack t hat cau ses u ser s' accoun t s t o be Aut locked h ored outby . This Cisco can Syeasily st ems,be w or accomp ldw idelished leaderfr om in net a sin w orgle king at tfack or ting he Ihost n t er.nDoS et . at t acks t y pically in volv e sen ding a lar ge num ber of u nw ant ed packet s t o t he t arg et net w or k fr om a I n t erned et wI P orad k indrgess. Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat spoof enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. A n ew for m ofMast D oSeratt he ackt s, er m dist s, rib con utcep ed tds,ent ial echn ofologies, ser v ice an ( DDoS) d devices , ev olved used in in 2t oday 000 . ' A s net D DoS w ork ating t ack indu str esour uses ry . Lear cesn frhow om tmo ult incor ip lepor sy at st e emint s er u sin netgwag or en kint gsof t echn t w are olog t hat ies is in tcon o at rolled LAN/ WAN fr omenv a mast ir onm erent . Comem syst plet . eThis w it h letnew s m or anedpack u pdat et sedbechapt t r ansm er s iton t edsecur t o t he it y ,DoS's st or age, t argopt et . ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Security Policy Asecur it y policy d ef ines and out lin es a comp any 's g oals and obj ect iv es for secur in g it s net w ork . A secur it y policy oft en inclu des t he follow in g sect ions: • •

Table of Content s

Accept able I ndexuse policy

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Passw or d policy

By Cisco Systems, Inc.

E- m ail an d I n t er net policy Pub lish er: Cisco Press

I ncident hanber dling Pub Dat e: Sep- tem 1 1, 2and 003

r esp onse pr oced ur e

I SBN: 1- 58 705 -1 19 -2

Rem ot e user access policy Pages: 11 28

Ex t r anet con nect ion policy Allow ed pu blic ser v ices policy An useion policy ( AUP) t lines allw hat user edr ef orerence n ot allow edides t o do on age t he of Theaccept u pdatable ed edit of t he b estou - selling in-aone netiswallow ork ing p rov cover net w or k. I t also def in es t he u ser 's r esponsibilit ies as an au t hor ized u ser . For inst ance, an AUP essent ial an d cu t t ing- edg e t ech nologies. m ight st at e t hat t he user mu st ensur e t hat t he ant iv ir u s sof t w ar e is r un once a d ay. A p assw d policy t lines h at olog const it ut es a tst d, pr how of t en als p assw or ds e f rom Conorcise ov er vou iew s of twechn ies essen ialr ong t o npassw et wor koring ofession at all levar els, changnov ed ,ice how t o passw ex pertor . ds are st or ed, an d w h o has access t o sy st em passw or ds. For inst ance, t h e passw ord p olicy m ight st at e t h at a rou t er ' s enable p assw or d m u st be t en char act er s in len gt h and mNew ust be chapt chang er s ed include ev er ycov 90erag d ays e or of im w henever por t ant at opics sy st em likeadm VoI inist P and r atEAP or leav es t he gr oup or com pany . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age An e- m ail and I nt er net policy ( EI P) ou t lines w hich u ser s hav e access t o e- mail and t he I nt er net . Aut hple, oredanbyEICisco w or ldw net w or king f orsiness t he I npu t errp n et . an d t hat For exam P migSy ht ststems, at e t hat e- mide ail leader can be in u sed only f or bu oses I nt er net access is lim it ed t o sit es d eem ed n ecessar y f or a u ser 's job fu nct ion. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net- hand w or kin g pan r ofessionals un dersteand d im plem ennet t cont por arityy int w orkwing An incident ling d response tporocedur ou t an lines how t he w orem k secur st er af fnet deals it h a tsecur echnologies. Mast ercht he er vmiru s, scon t s, tor echn anat d tdevices used t oday ' s netse w ork ing it y incident , su ast a outcep b reak anologies, int r u sion em pt . An int rin usion r espon indu st ry o incor er net or kin t echn olog inact t o awh LAN/ ir onm pr oced ur. eLear f or nanhow in t r tusion atpor t ematpte int defin es hwow t o gand w ho t oies cont en WAN an intenv r usion at tent em.pt Com is detplet ecteedw. it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net A r em w or otkin e user g p rof access essionals, policyr egar ( RAP) dless ou t of lines ex pert howise. em ploy ees access t he corp or at e net w or k fr om an un t r ust ed net w or k , such as an I SP net w ork . A RAP, f or exam p le, can specif y t hat each r em ot e Reader s w ill obt ain a gPrreat stkan( VPN) ding of LAN sof and n et w or kting, ar t icu lards ly (tOTPs) he user m ust u se Vir t u al ivatere un Netder w or client t wWAN are and oneim e ppasswor to har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on gain access t o a cor por at e net w or k or r esou rce w hile t elecom m ut ing f r om hom e. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o ext An en su r an reetcon connect cept comp ion policy r eh en(sion ECP)and ou trlines et en thow ion, band usiness ad ditpar ional t ner r esou s' conn r cesect f or ions fu rtare hercrsteat udy ed. . An Cov ECP,erag for einis st ance, also ext can end specif ed n ot y t only hat par t o tnew n er snar etewor allow k ing edconcep t o connect t s, but t o also t he cor t o old porer at, elegacy sit e only b y syst createm ings, aprsit ovid e- t in o-gsitaemVPN or e trunn ealist el ic using pict ur Trip e of le tDat he a realEncr w yp or ld t ion n etSt wan or dar k ingd en ( 3DES) vir onm . ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease An allow serpr vices policy ( APP)help ouing t lines n etmwake or k mor serveices are m ad e available pr odu ct ed iv it p y ublic an d im ov e eff iciency, t hewrhich eader in t elligent , cost - eff icientt o t he Idecisions nt er net . Ty p ublic forpically t h eir ,net w orkser s. v ices in clud e FTP, SMTP, HTTP, an d DNS. An APP w ould specif y t hat DNS ser vices ar e m ade accessib le only t o root DNS ser v er s.

Defense-in-Depth Security Solution Tr adit ional net w ork secur it y used t o be consider ed a point solu t ion or a single- dev ice solut ion. The p ar adigm w as, " Secur e t he n et wor k on ce or deploy a fir ew all, an d y ou ar e pr ot ect ed. " The net w or k secur it y com m unit y h as lear ned t hat net w or k secur it y , m uch lik e any business pr ocess, •is cyclical. Table of Content s •

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IThe nt e rn et w oritkying chnologie s Hin a ndbook ion secur w Te heel, sh own Figur ,eFour 52 -th1,Edit d ep ict s t he r ecom m ended pr ocess of m aint aining net w or k secur it y . The cent er of t h e w heel is t he secu r it y policy . I t has t h e follow ing phases: By Cisco Systems, Inc.

St e p 1 . Secu re t he n et w or k . I mp lem ent t he secu r it y mechanism s out lined in t he secu rit y policy. For in st ance, requ ire au t hent icat ion for all rou t er s an d sw it ches deploy ed on t h e Pubnet Datw e: or Sep k.tem ber 1 1, 2 003

Pub lish er: Cisco Press

I SBN: 1- 58 705 -1 19 -2 Pages: St e p 11 2 .28Mon it or

t he n et w or k . Deploy soft war e, such as an int r usion d et ect ion sy st em ( I DS) , t o m onit or act iv it y on t he n et w or k . For inst ance, y ou could deploy a net w or k I D S t o m onit or t r af fic allow ed t h rou gh t he I n t er net fir ew all.

St e p 3 . Test t he secur it y. Per iodically ch eck t h e net w or k' s secu rit y t o locat e new v ulner ies. of This eit h er g annet ouwt sid conr ef suerence lt ant orp using v ulner The u pdat ed abilit edit ion t heinbvolv est - es selling all-hirin in- one orkeing rov ides coverabilit age yof scan ner soft w ar e t o ident ify v uln er abilit ies and det erm ine t he eff ect iv eness of t he secur it y essent ial an d cu t t ing- edg e t ech nologies. m ech anism s im plem en t ed in t he secur e ph ase. A popu lar net w ork ing - map ping t ool is Nm ap ( " net w ork map per" ) . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom St eice p 4t .o Iex m pr ove nov pert . t he secu rit y . Based on t h e find ings in t he t est phase, enhan ce net w ork secur it y . For inst ance, if t he t est ing ph ase id en t ifies a v uln er abilit y in t he w eb ser v er New soft wchapt ar e, er inst s include all t h e appr cov erag opr iat ee ofsoft im por wart e ant p at t opics ch in like accor VoI d ance P andw itEAP h t h e v en dor 's r ecom m en dat ion. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

Figu r e 5 2 -1 . Secur it y W he el

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

The d ef ense- in - dept h st r at eg y is sim ilar t o w ear ing bot h a belt and suspend er s. I f t he b elt comes un done, t h e suspender s pr event y our t r ouser s fr om f allin g. I n net w ork s, t h e belt could be a filt er ing rou t er, and t he suspend er s could be a fir ew all appliance. I n ot her w or ds, do not rely on

only on e lin e of defense. Each line of def en se p rov ides ad dit ional p rot ect ion if on e line of def en se fails or is com pr om ised . Figur e 52 - 2 sh ows a def en se- in- d ep t h solut ion .

Figu r e 5 2 -2 . Li ne s of De f en se •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . II nn tFigur e fir st line of Hand d ef ense in, yFour our tnet w it ork f iltpr er ehensive ing fir ewall rouence t er s.t hat ern etew52 or -k2, in gt hTech nologies book h Ed ionare , is tahecom refer Dedicat ed f irew alls and I DS sensor s ar e you r second line of d ef ense. Cr it ical r esour as enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er ces, net wsuch ork ing ser v ers, ar e f ur t her pr ot ect ed b y host based I D S, w hich is y our final lin e of defense. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . A d efplet enseh an st rat y ised built on er t he pr em iseittyhat w or k ical has net m ult ip le et er s ory, Com e winit-hdept new d ueg pdat chapt s on secur , st aornet age, opt w or k inperim g, scalabilit zones. The secur it y policy dict at es t he p rot ect ion lev el im plem ent ed at each zone. Each and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essenzone t ial t o all pr otwect s dev t hat r equirr egar e difdless ferentoflevels ofise. pr ot ect ion an d t he com plem ent ar y secu rit y net or kin g pices rof essionals, ex pert t echnologies needed bet w een zones. The zon es can be d ivided int o su bzones if needed. Figur e 52 - 3 shsows net w ora kg div inder t o zon an dofsuLAN bzones. Reader w ill aobt ain reatided er un st anes ding and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . 5 2 -3 Secur it y Zone s also t o old er , legacy Cov erag e is also ext end ed n otFigu only troe new n et. wor k ing concep t s, but syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

NO TE

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

The t er m zone is used inst ead of per im et er t hr ough out t his chapt er . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing The t wo pr im ary zones in Figur e 52 - 3 ar e I nt er net and Cam pus. Th e I nt er net zon e is su bdiv ided t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing int o sm aller logical zones ( sub zones) —Public Serv ices and WAN. The I n t er net zone h as devices indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . t hat pr ov ide connect iv it y t o t h e I nt ern et . The ser ver s in t he Pub lic Ser v ices zone pr ovid e net w ork Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, ser v ices, such as HTTP an d FTP, t o I nt er net user s. Secur it y is im plem en t ed in t he I nt er net zone and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all using filt er ing rou t ers, a fir ewall appliance, and an int r usion det ect ion appliance. Host - based net w or kin g p rof essionals, r egar dless of ex pert ise. int r usion det ect ion is used in t h e Public Ser vices zone t o comp lem ent t hat secur it y m ech anism im plem ent ed in t he I nt er net zon e. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Threat Mitigation Not all secur it y t hr eat s can be elimin at ed , w hich is wh y t his sect ion f ocu ses on m it igat ing t hr eat s. Ult im at ely , a com pany mu st use it s secur it y policy t o d et er m in e t he accept able r isk and m et hod t o m it igat e any giv en t h r eat . The f ollow ing ar e r ecom m en ded met hod s of m it igat ing t he •st at ed secur itTable Content s y t hrofeat s: •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

U nau t hori z ed a cce ss— I m plem en t p rop er access con t r ols t hat define wh ich net w or k t r aff ic is allowed bot h int o and out of a n et wor k .

By Cisco Systems, Inc.

PubW lish er:k Cisco ea a ut hPress en t ica t ion—

Requir e t he use of passw or ds on an y net w or k dev ice. For st r ong aut hent icat ion is r eq uir ed , imp lem ent aut hent icat ion mI SBN: ech anism 1- 58 705 s,-1such 19 -2 as OTPs or biom et r ics.

Pub Datiron e: Sep tem ber 1 1,w2h003 env ment s in ich Pages: 11 28

W ea k p assw or ds— I m plem en t sy st em s t h at enf or ce t he cr eat ion of st r ong passw or ds. A st r ong passw or d is one t hat h as sev en t o 14 char act ers and does not include an y dict ionar y w or ds or com m on slang t er m s. Passw or d ag ing and hist or y sh ould also be im plem en t ed t o ensur e t hat users are requ ired t o p er iodically ch ange t heir passw or ds and t hat t hey do not r eu se passw or ds. Most oper at ing sy st ems can enf orce a st ron g p assw or d policy . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essentPial cu tffe t ingedgAny e t ech ackan e td sni rs— datnologies. a t r ansm it t ed in clear t ex t is su scept ible t o capt ur e b y packet sniff ers. Th e follow ing ar e com m on t ech niques u sed t o m it igat e t his t h reat : Con cise er v iew of nt t echn essen t ial n et wor k ing levcap els,t ur f rom - Stov r ong aust he i ca tolog ion ies — The use oft o OTPs redu ces pr t hofession e abilit y als t o at useallt he ed nov icepassw t o ex pert . ord , because it is v alid for on ly one use. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP - Sw i t ch ing — The use of sw it ches redu ces t he dir ect t hr eat t hat p ack et snif fing poses o at ing net w or k w her eologies hub s arlike edeploy edn. et wor k ing and st or age Cov erag e of tcut edge t echn opt ical - Cryby pt Cisco ogr apSy hy— Net wwor s t hat r eq uir eint he p r otfect imp Aut h ored st ems, orkldw ide leader netmwost or king or ion t he should I n t er n et . lem ent cry pt ogr aphy t hr ough t h e use of I P Secu r it y ( I PSec) , f or exam ple. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Ap pli ca tMast i on ler aytehe r—t erApplicat at t acks can nev be comused plet ely ed.wNew t echnologies. m s, conion ceplay t s,ert echn ologies, an derdevices in telim odayin' satnet ork ing v ulner abilit ies ar e d iscover ed on a daily basis. The f ollow ing ar e t h e com m on t ech niques indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . used it igatan e tdh uispdat t hr eat Com plet e wt oit hm new ed :chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. - St ay infor m ed of an y v ulner abilit ies associat ed w it h y our applicat ions b y ib ing t o ver endor secur y m ailing s. WAN n et w or k ing, p ar t icu lar ly t h e Reader s w illsubscr obt ain a g reat un der st anitding of LANlist and har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on - I n st all secur it y- relat ed sof t w are pat ches. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cepthost comp r eh en r et enI DSs t ion, t and ditat ional r esou r ces f or fu rt her udy .ion - Use - and netsion w or and k- b ased o detad ect t acks lau nched against apst plicat Cov erag e isser also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy v ers. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals and an gu idhor elines f or The opt im izing syst em ance w ill incr V ir uses,oper w oratme.s,Tools a nd Troj se s— use of an t ivir us per soffor twm are p r ovides adease eq uat e pr odupr ctot iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff ect ion f or deskt op sy st em s. Per son al fir ew alls can also be u sed on deskt op syicient st em s. decisions t h eirI DSs net wcan ork s. Host for - based be used on ser v er s r equir ing add it ion al pr ot ect ion. I P spoofi ng— I m plem en t p rop er ingr ess and eg ress f ilt er ing as r ecom m en ded in RFC 28 27. Filt erin g RFC 19 18 add resses is also encour ag ed . D e nia l of se rv i ce — I n add it ion t o ingr ess and egr ess f ilt er ing , coord in at e w it h you r I SP t o

im plem ent r at e limit in g on t h e I SP' s r out er . Rat e lim it ing can also be im plement ed on you r edge r ou t er . Enable an y ant i- DoS feat ur es t h at can con t r ol t he num ber of conn ect ions allow ed t o a specif ic host .

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Security Tools A k ey aspect of secur it y is k now ing w hat y ou w an t t o pr ot ect . Many secur it y issues ar ise because a v uln er able d ev ice w as plug ged in t o t h e net w or k w it hout t he n et wor k ad min ist r at or 's k now led ge. A com plet e net w or k inv ent or y m ust b e t ak en t o en su re t hat you k now wh at ex ist s on •y our n et w or kTable and ofw Content hat sersv ices ar e av ailable. •

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IAntpeor rn et or k ing Te chnologie H a ndbook , Four Edit ion t-w scann ing t ool is t yspically used t othcondu ct t he n et wor k in vent or y . The follow in g ex plains tBy heCisco basic act ion s of a p ort scan ner : Systems, Inc.

PubI lish er: Cisco t sends I n Press t er n et

Cont rol Message Pr ot ocol ( I CMP) echo p ack et s t o discov er dev ices on t he r ef er r ed t o as ping sw eepin g t he net w or k .

Pub Dat beris 1 1,com 2 003 net we:orSep k. tem This mon ly I SBN: 1- 58 705 -1 19 -2

IPages: t sends Tran sp ort Con t r ol Pr ot ocol ( TCP) con nect ion r equest p ack et s t o devices t o 11 28 det er min e if com m on TCP ser vices, such as HTTP, FTP, an d Telnet , ar e av ailable. I t sends User Diagr am Pr ot ocol ( UDP) t r aff ic t o dev ices t o det erm ine if UDP ser v ices, su ch as DNS and SNMP, ar e av ailable. The pdatk ed edit of t he est - selling allin- ine one ifnet r efices erence cover aget ool of has A n etuwor secu r ition y scann er bis used t o det erm n etwwork or ing k serv are pvrov ulnides er able. This essent ial anof d cu t t ingedg e itt ech nologies. a d at abase k now n secur y v ulner abilit ies an d ch eck s t o see if t he n et w or k serv ice is v ulner able. The f ollow ing ex plains som e of t he t echniq ues t his t ool uses t o d et er m in e if a serv ice is v ulner able: Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . I t checks t he op er at ing sy st em v ersion. This is called finger pr in t in g. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP I t checks t he v ersion of t he sof t w are. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age I t sim ulat es t he act u al at t ack . For inst ance, if a ser v er does not pr oper ly hand le a long URL Aut h ored by scann Cisco er Sy can st ems, leader net wt or kingiff or t erret n etu.rn s a specific r eq uest , t he senw d or a ldw longide URL and in check o see t h et he serIvner code. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables w or r ofessionals un derst an d tim plemsecur en t cont Here arenet som e kin ot hgerpsecur it y t oolst ot hat can and be used o help e y em our por n etar w yorint k : er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet Nmeapw it ishan new op an en -dsou u pdat r ce ed u t ilit chapt y forernseton wor secur k exitplor y , st ator ion age, or secur opt ical it ynet aud w or it ink g. in g, Nm scalabilit ap r unsy,on and speed, m ost t tyhpes is book of com is a put com er s,plet and e an botdhu console p- t o- d atand e r efgr eraph ence ical t o ver t hesion t opsics ar tehat available. are essen A tGTK+ ial t o all net w or fr on kintgend p roffor essionals, Nmap isr egar av ailable dless for of ex user pert s ise. w h o pr efer a gr aphical u ser int er face t ool inst ead of a com m and- line in t erf ace t ool ( see Figur e 52 - 4) . Visit t h e Nm ap W eb sit e at Reader s w .in ill obt aine.aorggreat uneder an ding ww secur f or er m or infst orm at ion.of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t ornew concep t s,t but Figu e 5 2n et -4wor . Nk ing m ap Fr on Enalso d t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . is ga Tech f ree nologies secu rit y -Hand aud itbook ing t ool t h at en, tis ifya t com he vpr ulner abilit ies t h at ex ist on you r I n t ernNessus et w or k in , Four t h can Ed it id ion ehensive refer ence t hat net w or k. Visit t he Nessu s Web sit e at w w w .n essus. org f or m or e inf orm at ion. A sam ple enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Nessus repor sh ow e 52 t echnologies. Mastterist he t ernmins, Figur con cep t s,- 5. t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Figudless r e 5of2ex -5pert . Nise. essu s Sa m pl e Re por t net w or kin g p rof essionals, r egar Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Som ar Sof t has nov ice t o ex perta. su it e of fr ee Microsoft Wind ow s ut ilit ies aim ed at p rov iding t h e sy st em adm inist r at or inf orm at ion needed t o secu re a Wind ows sy st em. The f ir st is Dum pSec, w hich is a secur y-sauinclude dit ing pr ogr amef or Wind s NT an d like WinVoI dowPs and 20 00. The secon d is D um pEv t , New chaptiter cov erag of im porow t ant t opics EAP w hich is a Wind ow s NT pr og ram t o d um p t he Ev ent Log in a for m at su it able for im p ort in g int a d at Theedge t h ir d t is Duologies mp Reg,likwehich is a npet rog r am forand Winst dow s NT and Window s Covo erag e abase. of cut t ing echn opt ical wor k ing or age 95 t h at du m ps t h e Regist ry , m ak ing it easy t o f ind k ey s and v alues t hat cont ain a st r ing. Aut h ored by Cisco st ems, orw ldw leader net wf or king er n et . Visit t he Somar Sof tSyWeb sit ewat w wide .som ar sofin t . com m or ef orinft he ormI n att ion. I n t ernJohn et w ort hkeinRipp g Tech Hand Four tor h dEdcritack ion ,ing is at ool com pr ehensive er nologies is an op en - soubook r ce p, assw t hat can identrefer if y wence eak t hat enables net ord w ors. kinVisit g p r tofessionals unper derst andsit ane datimwplem enen t cont em por/ joh ar yn/intf er w eork ing passw he Joh n t het oRip Web w w .op w all. com or net m or t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing inf orm at ion. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary The I n t er net is no lon ger ju st a net w ork u sed t o t ran sfer e- mail messages and files. I t has chang ed our daily lives and h ow comp anies conduct business. Net w or k secu rit y plays a k ey role in ach iev ing goals f or bot h ind iv idu als and comp anies. I n divid uals exp ect t heir infor m at ion t o b e •k ep t conf ident Table Content s ial wofhen pu rchasing it ems online or r egist ering f or e- lear ning . The gov er nm ent is •r eq uir ing com I ndex pan ies t o secu re t he dat a com panies st ore on t heir net w ork s. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

The comSystems, m on t hrInc. eat s posed t o a n et wor k ar e u naut h orized access, weak au t hent icat ion, By Cisco passw ord s, packet sn iff er s, app licat ion layer at t ack s, v ir uses, w or ms, Tr oj an h orses, I P spoof in g, and DoS at t acks. Pub lish er: Cisco Press

e: kSep tem ber 2 003 is t he d ocu ment t hat exp lain s and dict at es t he lev el of secur it y a ThePub n etDat wor secur it y1 1,policy I SBN: 158 705 -1 19 -2 com pany im plem en t s on it s net w or k. A secur it y p olicy ou t lin es su ch t h in gs as h ow t h e com p any 's users Pages: can u se 11 28 t he net w or k, how t he com pany h andles an incident , an d h ow a com pan y connect s t o par t ner net w or ks.

A d ef ense- in - dept h secur it y solut ion is based on t h e pr inciple t hat m ult iple zon es of d ef ense ar e needed t o pr ot ect t h e net w or k. Each zon e im plem ent s com plem en t ar y defense m ech anisms t o ensur e t hat if one zon e' s pr ot ect ion f ails, t he nex t zon e can p r ev ent t he at t ack f rom su cceeding. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial anion d cut echniqu t t ing- edg t ech nologies. The m it igat ese used t o pr ot ect a n et wor k d ep en d on t h e t hr eat p osed. Passw or d aging is u sed t o m it igat e at t emp t s t o pr ot ect against passw or d at t acks, n ot I P sp oofing . The ingr ess and f ilt er t echniqu 282 7 arpr e ofession u sed t o als mit igat e lev I P spoofin g Con ciseegr ovess er v iew s ing of t echn olog es ies descr essenibed t ial in t o RFC n et wor k ing at all els, f rom at t acknov s. ice t o ex pert . Sy st em adchapt m in isterr at s can cov useerag por te scann er s,t ant v ulner abilit y scan ners, d passw or d- cr acking New s or include of im por t opics like VoI P and an EAP t ools t o help im pr ov e net w or k secur it y . Por t scanner s help discov er w hat net w ork devices ar e on t he net w ork hatt ing ser edge vices tare available. erical abilit ident weak nesses w it h Cov eragand e ofwcut echn ologies likVuln e opt n yet scanner wor k ingsand stify or age dev ices on t he net w ork , such as r out er s, sw it ches, ser v er s, an d d esk t op com pu t ers. Passw ord crack ing en forSy cestpasswor d policies b y ident ing t hat Aut ht ools ored help by Cisco ems, w or ldw ide leader in ify net w orpassw king for ordst he I n tdo er nnot et . m eet t he r eq uir em ent s f or a st ron g p assw or d. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1: •

What f act or s h ave in fluenced t he im por t ance of net w or k secur it y ? Table of Content s

I ndexh ave t he gr ow t h of t he I n t er net and emer ging t echnologies af fect ed net w or k How I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion secur it y ? •

2:

By Cisco Systems, Inc.

3:

How d oes a secur it y p olicy af fect a com pan y' s net w or k ?

Pub lish er: Cisco Press

4:

Pr ovid e an ex am ple of a d ef ense- in - dept h secur it y solut ion.

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 58 705 -1 19 5 : 1-List com m-2on

t hr eat s against net w ork s.

Pages: 11 28

6:

Which net w or k secur it y t hr eat at t em p t s t o f lood a net w or k w it h unw ant ed pack et s?

7:

What t y pe of at t ack in volv es send ing e- m ail at t ach ment s? How is t h is t hr eat it igat The u pdat edmedit ioned? of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. 8 : Descr ibe h ow t o m it ig at e I P spoof ing at t acks. Con 9 :ciseHow ov erdvoes iewas sw of titechn ch edolog inf rast ies ressen uct u re t ialmtitoigat n etewor sn kiffer ing at prtofession ack s? als at all lev els, f rom nov ice t o ex pert . 1 0 : What t y pe of secu rit y t ool discover s dev ices and n et w or k serv ices av ailable on a New chapt include cov erag e of im por t ant t opics like VoI P and EAP net werors k? Cov e of tcut t ing edgeritt echn ologies wor kabilit ing and 1 1 :erag What y pe of secu y t ool ident iflik iese dopt ev ical ices'nvetulner ies? st or age Aut by tCisco st ems, or ldw ideif leader in passw net w orord king 1 2 h: ored What y pe ofSysecu rit y w t ool ident ies w eak s? f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information Websites •

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I ndex

•I nt CERT, w .cer t . org s H a ndbook , e rn et w w orw k ing Te chnologie

Four th Edit ion

By Cisco Systems, Inc.

• Cisco SAFE, w w w .cisco. com / go/ safe Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

• Fact Sh eet on EU Pr ivacy Dir ect iv e, w w w .d ss. st at e.ct . us/ d ig it al/ eu pr iv . ht m l I SBN: 1- 58 705 -1 19 -2

Pages: 11 28

• Healt h Pr iv acy Pr oject , w w w .h ealt h pr ivacy . org / • RFC 1 918 , Add ress Allocat ion f or Pr iv at e Net w ork s , w w w .iet f .or g/ rf c/ rf c1918 . t xt The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent an d, Sit cuet tSecur ing- edg t ech book nologies. • RFCial 2 196 it y eHand , w w w .iet f .or g/ rf c/ rf c2196 . t xt Con cise, Net ov er v iewAd s of t echn olog iesFilt essen t own.iet et wor als at all lev els, f rom • RFC 2 827 w ork dr ess I ngr ess er in gt ial ,ww f .or kg/ing rf c/pr rfofession c2827 . t xt nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Books

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age by Cisco SyestIems, w or ldw leader in net w or king f or t he er n et • CarAut t er h , ored Earl. Cisco Secur nt r usion Det ide ect ion , Cisco Pr ess: I ndianap olis,I n2t 001 . . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat kinid, g pan r ofessionals un derst and anXd Fir imew plem t cont em por ar y intPr eress, net w2ork ing •enables Chapmnet anw, or Dav d An dy Fox.t oCisco Secur e PI all ,en I nd ianapolis: Cisco 001 . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . •Com Mason And . Cisco t ual er Prsivon at esecur Net witor I nd ianapolis: Cisco ess, 2 001 . y, plet e, w it hrew new an d uSecur pdat e edVir chapt y ,ksst,or age, opt ical net w orPr k in g, scalabilit and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. • Wen st r om , Michael. Man aging Cisco Net w or k Secu r it y , I nd ianapolis: Cisco Pr ess, 2 001 . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Mailing Lists and Newsletters t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst ovid in g list a m, worwewr.secur ealist ic pict e of t he real- w or ld n et w or k ing en vir onm ent s in w hich • Buem gt rs,aqprm ailing it yf ocuurs.com pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h netsu w lt ork s. Secur it y By t es, • Cisco Secur it eir y Con ing w w w .cisco. com / en/ US/ net sol/ n s1 10/ n s1 29/ n s131/ ns267 / net w ork ing _solu t ions_new slet t er s_list . h t m • NTBu gt r aq m ailing list , w w w .n t bu gt r aq. com

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Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Glossary Terms a ut he nt i ca t i on. The p r ocess of v er ify ing an ident it y claimed by or for a sy st em ent it y . •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

D a t a Encry pt i on St an dar d ( D ES) .

By Cisco Systems, Inc.

A U. S. gov er nm en t st and ard ( FP04 6) t hat sp ecifies t h e Dat a Encr yp t ion Alg orit h m and f or using it t o pr ot ect u nclassified, sensit ive d at a.

Pub st lishat er: esCisco t he Press p olicy

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

I nt e rn et P rot ocol Secur it y ( I P Se c) . A collect iv e nam e f or a secur it y ar ch it ect ur e an d set of p r ot ocols t hat p r ovide secur it y ser v ices f or I nt er net Pr ot ocol t r af fic. See w w w .iet f .or g/ rf c/ rf c2401 . t xt . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. in t ru si on d et e ct ion . Con cise itovy er v iew t echn olog t ial t o nsyetstwor ingent prsofession all of levfels, f rom A secur ser v ices of t h at m onit or ies s anessen d analyzes emkev f or t he als p ur at pose in ding and nov ice t o ex pert . pr ov iding r eal- t im e or n ear - r eal- t ime war nin gs abou t u naut h or ized at t em pt s t o access syst em r esou rces. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age one - t i m e pa ssw ord ( OTP ) . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . A sim ple aut hent icat ion t echniq ue in w hich each passw or d is used on ly once as I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat aut h en t icat ion inf or mat ion t h at v erif ies an ident it y . Th is t ech nique cou nt ers t he t h reat of a enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing r ep lay at t ack, w hich u ses passw or ds capt u red by w ir et apping . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all pi ngspeed, sw e e p. net w or kin g p rof essionals, r egar dless of ex pert ise. An at t ack t hat sen ds I CMP ( RFC 792 ) echo r equest s ( p in gs) t o a r an ge of I P ad dr esses, Readerwsitw obt reating er un der WAN n et w orilit k ing, h illt he g ain oal a ofgfind host s st t han atding can of be LAN pr oband ed f or vu lnerab ies. p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov e ilisitalso v ulnerag er ab y . ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals at e. Tools gu id elines f or opt izing syst emorper forat mion ance ease A f law oroper w eak ness in aand sy st em' s design, im pim lem ent at ion, oper anwdillmincr an agement pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient t hat can be exp loit ed t o violat e t h e syst em 's secu rit y policy . decisions for t h eir net w ork s.

Chapter 53. Directory-Enabled Networking Obj e ct i ve s • •

Table of Content s

Pr ovid e a b rief int r oduct ion t o object - or ien t ed inf or mat ion m odeling. I ndex

I nt e rn Pr et w or k ing s H a ndbook th or Edit ion ovid e aTe b chnologie rief int r oduct ion t o, Four direct ies. By Cisco Systems, Inc.

Pr ovid e a b rief over v iew of D EN. Pub lish er: Cisco Press

Show how D EN w ill be used in Cisco pr odu ct s.

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58led 705 -1 19 -2 Dir ect ory - enab net w ork ing is not a pr odu ct or ev en a t echn ology . Rat h er , it is a ph ilosop hy t hat uses Pages: t he 11 28 Direct or y- Enabled Net w or k s ( DEN) specif icat ion t o bind ser v ices av ailable in t he net w or k t o client s u sing t h e net w or k. The DEN specif icat ion enables app licat ions t o lever age t h e capabilit ies of t he n et w or k as w ell as b et t er su ppor t t he needs of t h e app licat ions u sin g it .

DEN is in realit y t w o t hings: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. 1 . A specificat ion of an ob ject - orient ed inf orm at ion m odel t hat m odels net w or k elem en t s and ser v ices as p ar t of a man aged en vir onm ent in a reposit or y - in dependent fash ion Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov t o exof pert . inf or mat ion t o a f or m t hat is suit able f or im plem ent at ion in a d ir ect ory 2. A mice ap ping t his t hat uses LD AP or X. 50 0 as it s access pr ot ocol New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Mor e inf or mat ion on dir ect or y - enabled n et wor k ing can b e obt ained fr om t he book Dir ect ory CovNet erag ofs,cut edge t echnerologies lik e opt ical n et wor k ing and st or age En abled w eork b yt ing John St r assn . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Object-Oriented Information Modeling An infor m at ion m odel is fu ndam ent ally dif fer en t t h an a dat a m odel or a schem a ( Figur e 53 - 1) . Here are d ef init ions of each: •

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D a t a mIod el — A concr et e repr esent at ion of t h e char act er ist ics of a set of r elat ed object s in ndex erwms appr iat e t so Haa ndbook specific datth a st orion age and access t echnolog y I nt e rn tet or k ing Te opr chnologie , Four Edit •

By Cisco Systems, Inc.

Sche m a— A set of dat a m odels t hat descr ibe a set of r elat ed object s t o be m anag ed

PubI lish er: Cisco Pressm odel — nf orm a t ion

A t echnology- ind ep en dent sp ecificat ion of t he char act er ist ics of a set t o ot h er object s in a m anag ed env iron ment , w it h no r ef erence t o -1 st19 orag I SBN: 1- 58 705 -2 e m et hods, access p rot ocols, or specif ic t y pe of r eposit ories

Pub ofDat obj e: ect Seps, teman berd 1t1, heir 2 003relat ionships

Pages: 11 28

Figu r e 5 3 -1 . I nf or m at ion M ode ls, Da t a M ode ls, a nd Sche m at a The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tThe o enpsu rearcon cept comp and t ion, ad dit r esou r ces f orr epr fu rtesent her stat udy r im y pu r pose of rteh heen infsion or mat ionr et men odel is and t o defin e ional a single u niv er sal ion. of Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy t he dat a and object s t o be m anag ed t h at is ind ep en dent of any specif ic st orag e t ech nology an d syst em s, procol. ovid inThe g a in mfor or e ealist ic pict of t he w orallld appr n et wopr or kiat ing en ject vir onm access pr ot m rat ion mod el ur is eused t o realdefine e ob s in ent t hes in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease env iron ment t hat ar e t o be m anaged and t o sh ow how t hey r elat e t o each ot her. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions Becau se t he for nat t h eir ur enet ofwt he orkob s. ject s and t he dat a descr ibing t hese obj ect s is d iff er ent , it is t her efor e r easonab le t o ex pect t hat dif fer en t d at a st or es w ill be r eq uir ed t o r ep resen t t h ese obj ect s and t heir int er relat ionships. For ex amp le, a policy m ight be w r it t en t o chang e t he t yp e of qu eu in g on a par t icular int er face of an access r out er . This m ight be a f unct ion of t he n um ber of oct et s dr opp ed and t h e num b er of u ser s of specif ic ser v ice t yp es ( su ch as g old v s. silv er v s. br onze ser vice) . St or ing t he r esult s of an SNMP coun t er r ecor ding any t hin g t o do w it h t he

nu mb er of oct et s d r opped is inapp rop riat e f or a dir ect or y because t he cou nt er dat a chang es m uch t oo f ast f or t he d irect or y t o k eep up w it h. How ev er, user ser vice def in it ions, as w ell as t he policy it self , ar e ver y app rop r iat e t o st or e in a dir ect ory b ecau se t hey can t h en t ak e adv ant age of t he replicat ion mechanism s t hat dir ect or ies hav e. As w ill be seen lat er in t his chap t er , d irect or ies ar e v er y w ell suit ed t o ser v e as p ublicat ion m echanism s; pub lishin g d at a in a d irect or y enables div erse app licat ions t o ex ch ange an d sh are dat a. The ad van t age of t h e inf orm at ion m odel, t hen, is t o b e cap able of r ep r esent ing how t hese • Table of Content s dif fer en t t y pes of dat a and obj ect s relat e t o each ot her in a sing le con sist ent m anner w it hou t • I ndex being biased b y t he capab ilit ies of any one par t icular r eposit ory . Pu t an ot her w ay , t he I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion inf orm at ion m odel specif ies a logical r eposit or y t hat descr ibes t h e obj ect s an d d at a t o be By Cisco Systems, Inc. m anaged. The logical r eposit ory map s int o a set of ph ysical d at a r eposit or ies. The sp ecific set of dat a r ep osit or ies t o b e used d ep en ds on t h e need s of t he ap plicat ion s using t he reposit or ies. Th is enables he Cisco developer t o ch oose t he ap pr opr iat e dat a st ore( s) an d p r ot ocol( s) t o u se f or a given Pub lishter: Press appPub licatDat ion. e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

App licat ions h ave diff er ent need s, r eq uirin g d iff er ent dat a st or es. This isn' t a pr oblem—y ou simp lyPages: build11a28set of m app ings f r om t he ( sing le) infor m at ion m odel t o each t y pe of dat a st ore t hat is being used. I n gener al, t hese m apping s w ill be d if fer ent b ecause each t yp e of r ep osit or y uses a specific t y pe of st or age t echn ology t hat uses one or mor e p art icular access pr ot ocols. Th is m akes on e sch em a diff er ent fr om an ot her. For ex am ple, a d irect or y sch em a is fun dam en t ally dif fer en t t h an a r elat ional dat ab ase schem a. How ev er , all sch em at a so der ived can b e r elat ed t o The uot each pdat h eredbecau edit ion se t of hey t he ar be est all- der selling iv edallfr om in- one a univ net erwsal orkinf ingorrmat ef erence ion m odel. p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

DataCon Models to Specific ofk ing Repositories cise ov erAre v iew sBound of t echn olog ies essen t ialTypes t o n et wor pr ofession als at all lev els, f rom nov ice t o ex pert . A d at a m odel r epr esent s t he f und am en t al char act er ist ics of an ob ject or a set of obj ect s in a w ay chaptt oeras par include covt yp erag e of por t opics likele,VoI P and t hat isNew sp ecific t icu lar e of r epim osit ortyant . For ex amp t here areEAP f un dam en t al dif fer en ces bet w een a rou t er obj ect and a user obj ect . Fu rt herm or e, each obj ect w ill hav e a d iff er ent Cov erag e ofincut t echninologies ical et wor ingt hand im plem ent at ion a dt ing ir ectedge ory t han a r elat lik ionealopt dat ab nase, evken oughst tor heage sam e inf or m at ion is r ep r esent ed in bot h schem at a. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The d irect or y imp lem ent at ion w ill consist of a set of ent r ies t hat hav e at t r ibut es d ef ined Iaccor n t erndet nologies Hand , Four t hesEdan it ion , is sat hcom ehensive ence inwg or t ok in t hge Tech sy nt axes ( such as book t he dat a t yp d way at yprou can searrefer ch f or andt hat fin d enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net inf orm at ion in a dir ect ory ) su ppor t ed in LDAP an d X. 50 0. I n add it ion , it em ph asizes w ork ing tcont echnologies. Mast er m t he m s, ibes con cep t echn ologies, anion d sh devices t oday netand w ork ainm ent . Con t ain entt er d escr t het s, sub ord inat e r elat ips betused w eeninon e obj' sect oting her indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm obj ect s in t h e sy st em. I n ou r exam ple, a user object is u su ally " con t ained" in , or scoped by ent , a. Com plet ew h new, an d u as pdat chapt s on itional y , st oru age, ical net w orwk in y, high er - lev elitobject such a ed g rou p oreran orgsecur anizat nit ( aopt f ancy X. 500 org, d fscalabilit or and speed, t h is book is a com plet e an d u pt od at e r ef er ence t o t he t op ics t hat are essen t ial t o all " div ision " ) . net w or kin g p rof essionals, r egar dless of ex pert ise. The sam e user obj ect im plem ent ed in a r elat ional dat ab ase w ill h ave a dif fer en t st r uct ur e t h an Reader obt ain er un der st an and WAN n et ing,esent p ar t in icuglar t h e w ill t he samsewuillser ob jecta g imreat plement ed in a ding dir ectof or LAN y . For exam p le, dw ator a kr epr t hly e user har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on be sp read acr oss one or m ore t ables inst ead of ex ist ing w it hin indiv idual en t r ies in a direct or y. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Fur t her mor e, t h e dat a w ill be st r uct ur ed slight ly diff er ent ly , t o accom m odat e d if fer en t d at a tstor en comp ehocols en sion and r etben ion, and ional im r esou r ces at f orion fu rt herpar st udy uctsu urre es con andcept access prrot t hat can e tused in a ad datdit abase plement com ed t.o t he Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy dir ect or y im plem en t at ion. Relat ionship s t o ot her obj ect s, r at her t h an cont ain m en t of obj ect s, is syst or e rbet ealist ic pict e of t hedat realw or ld n et w or k ing en vir ent s in one em of ts,heprmovid ain in dg iff a er m ences w een a rur elat ional abase imp lem ent at ion andonm a direct or yw hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease im plem ent at ion . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions t h eir w ork s.ion m odel u ses ob ject - or ient ed t ech niqu es t o m odel inf or mat ion An obj ect -for or ien t ed net in for m at abou t a par t icu lar set of obj ect s t h at ex ist in a m anaged env ir on ment . The k ey diff erence in an inf orm at ion m odel is t h at , in addit ion t o d escr ib ing t he char act erist ics of ent it ies, it also descr ibes t h eir b eh avior and in t eract ion w it h each ot her . These lat t er t w o concept s m ay n ot be able t o be capt ur ed in all r ep osit or ies. Thus, t h e inf orm at ion m odel pr escr ibes a m eans f or r elat in g d iffer ent t yp es of in for m at ion, r egar dless of t he t y pe of d at a st or e t hat is being used. I t

is up t o t he d ev eloper t o choose t h e r ight t y pe of r ep osit or y an d ot her aux iliar y t ools t o im plem ent all f acet s of t h e infor m at ion m odel if t he r eposit ory it self is not cap able of im plem ent in g t h e dat a and r elat ion sh ip s in t he inf or mat ion m odel. An ex am ple m ay h elp t o clar ify t h is. Think of basing a decision t o chang e t he t yp e of condit ionin g t hat a par t icular t y pe of t r af fic is r eceiv in g on t he net w or k env ir on ment . This decision m ay depend on sev eral fact or s: • •

Table of Content s I ndex The n um ber of dr op ped oct et s in a p art icular in t er f ace

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

The ser vicelev el By Cisco Systems, Inc.

agr eem ent assign ed t o a par t icular u ser or applicat ion

Hist orical an d ot h er relat ed in for m at ion Pub lish er: Cisco Press Pub rDat Sep tem 1 1,f 2un 003 These epe:resen t t ber hr ee dam en t ally diff er ent t y pes of infor m at ion. An y one sing le dat a st or e is pr obabI ly SBN: not 1- 58 opt 705 im-1al 19 -2 f or st orin g t h is infor m at ion becau se of t he inh er ent diff erences in volum e, fr equ en cy of11u28pdat e, t yp es of q ueries, and dat a st r uct ur es used t o st ore and r et r ieve t hese d at a. Pages: The in for m at ion m od el repr esent s t he r elat ionships t h at each of t hese dat a st r uct u res h ave w it h each ot h er and w it h ot h er object s in t he m an aged env ir onm en t . This en ables t he dev elop er t o design opt im ized r eposit ories t o st or e each t yp e of infor m at ion and t hen r ecom bine t he dat a as app rop riat e. As anot her ex amp le, diff er ent dat a mod els could be used t o m odel a r out er int er face, users, an d d iff er ent t yp es of ser vices and app licat ion dat a t hat ar e pr ovid ed on behalf The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of of dif fer en t user s. Howev er , t he dat a m odel can' t m odel t he int er act ion b et w een t h ese ob ject s. essent ial an d cu t t ing- edg e t ech nologies. This is w h at t h e infor m at ion m odel does. Ther ef or e, we can see t hat diff er ent dat a m odels will b e used t o m odel d if fer en t p art s of t he d at a d escrib ed in t he in for m at ion m odel.

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Thu s,nov alt houg d irect ice t oh ex pert or . ies ar e a ver y im por t ant t y pe of r ep osit or y f or st or in g in for m at ion about net w or k elem ent s an d ser vices, t hey are not t he only t yp e of dat a st or e t hat can be u sed. How ev er , because ect or ies cont he dt ef init ions ser s, applicat ions, and ot h er New chapt er s dir include covusually erag e of im ain por ttant opics like of VoIuP and EAP net w or k r esour ces, t hey ar e oft en used in all app licat ions t o som e ext ent . That is w hy t h is chaptCov er concent r atcut es t on he m ap pingologies of DENlikinfor mical at ion a for m and t h at st enab les D EN d at a t o be erag e of ing t edge t echn e opt n ett owor k ing or age st or ed and r et r iev ed in a d ir ect or y. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Realization of the Information Model enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Cu rr st ent t w on im por tt oanincor t st and atwion m odels ar eolog being dev ed : WAN t h e Com monm on ent . indu ryly. ,Lear how porar atde inf intor erm net or kin g t echn ies in t o elop a LAN/ env ir ICom nf orm at ion Model ( CI M) an d t he Dir ect or y En abled Net w or ks m od el, w h ich is an ex t ension of plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, CI M. Bot h of t h ese ar e cur r ent ly gov ern ed b y t he D MTF. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e The Common Information Model har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions CI M is an ob ject - orient ed inf orm at ion m odel t hat descr ibes h ow a sy st em and it s comp onent s t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . m ay be m an aged. I t is defined by t h e Dist rib ut ed Managem ent Task For ce ( DMTF) . On going Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy dev elop ment of CI M is par t of an ind ust ry - w ide in it iat iv e f or enabling ent er pr ise m an agement of syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich dev ices and ap plicat ion s. A pr im ary goal of CI M is t he pr esent at ion of a consist ent v iew of t he pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease m anaged env ir on ment , independ en t of t h e var ious p r ot ocols an d dat a f or m at s supp ort ed by pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient t hose d ev ices an d applicat ions. Many net w ork in fr ast ru ct ur e and m anagem ent sof t w are decisions for t h eir net w ork s. pr ov iders hav e accept ed CI M as an in for m at ion m od el for ent er pr ise man agem en t t ools. CI M is a lay er ed infor m at ion mod el, meanin g t h at it consist s of a set of subm odels t hat bu ild on and r efine t h e k now led ge pr esen t in out er , m or e gener ic lay er s. Sp ecif ically, a set of com mon abst r act ions and f unct ions are d ef ined in t h e core m od el ( see Figur e 53 - 2) . Th ese ar e t h en enhan ced t hr oug h t he def in it ion of sub mod els t hat are lay ered on, or use, t he inf or m at ion in t his

core mod el. One of t h ese lay er s is t he net w or k m odel, w hich cam e f rom DEN.

Figu r e 5 3 -2 . Th e CI M La y er e d I nf or m a t ion M ode l

•

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Version 2. 2 of CI M consist s of a cor e m odel, w hich is used t o define con cept s in t h e infor m at ion The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of m odel t h at app ly t o all areas of m anag em ent . I t is comp rised of a set of classes, at t r ib ut es, essent ial an d cu t t ing- edg e t ech nologies. m et hods, an d r elat ionships t h at d escr ib e comm on concep t s f or m anaging sy st em s and sy st em com ponent s. Th e cor e m od el is t he f ound at ion f or t h e class inh er it ance an d r elat ionship hier archies, h e sbasis for all com on and odels. Con ciseand ov erisv tiew of t echn olog ies m essen t ial ext t o ension n et wor kming pr ofession als at all lev els, f rom nov ice t o ex pert . Com m on mod els are f ocused set s of classes, at t r ib ut es, m et h ods, and r elat ion sh ips t h at ex t en d par t icular in t he cor e erag m odel. exam ple, t h e core m od generically defines a ser v ice. New concept chapt er ss include cov e ofFor im por t ant t opics like VoI Peland EAP The n et wor k m od el refin es t his concep t t o descr ibe d iff er ent t yp es of ser vices t hat ar e specif ic t o net w or kinerag g, such w ardt echn ing and r outlik inge of r aff ic. Cov e of as cuttthe ingfor edge ologies optt ical n et wor k ing and st or age The bAut est hwored ay t obyt hink ofSy a st com m on mldw odelide is leader as a setin of abst ions Cisco ems, w or net w orract king f or tthat he Ifrnequent t er n et .ly occur in a specif ic m anagem en t d omain . The seven comm on m odels ar e t hese: I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Sy st em — Defines sys,st con em cep comt s, p onent such asancomp ut er syst emin, oper at' sing eming , t echnologies. Mast er t hektey er m t echns,ologies, d devices used t oday netsyst w ork file, and t h e r elat ionship s r eq uired t o assemb le t hem . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, D e vi cet h—is Defines t oplet r ealize sical h ardt ow are how t o are m odel and speed, book is how a com e an dphy u pt o- ddevices at e r ef erinence t he and t op ics t hat essen t ial t o all connect ions b et w een d ev ices su ch as st or age d ev ices, m edia, sensors, p rin t er s, an d p ow er net w or kin g p rof essionals, r egar dless of ex pert ise. supp lies. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e plipr caot t iocols, on— Defines molv anag soft w ar eent inst w it hinf in or a mat sy stion em.is pr ov ided on har dwAp ar e, and serhow v icest oinv ed .e Fu ndam al allat t echion nology a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions N e t w ork — Defines r ef inem en t of t h e logical elem en t class hierar chies t o mod el net w ork t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . elem ent s an d ser vices. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich P hy si ca l— Defines ph ysical or ganizat ion , cont ainm ent st r uct u re, an d com posit ions of pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease dev ices and d ev ice in t erconn ect ions. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for Models t h eir net w ork s. U se r— users, g rou ps, and or gan izat ion s, and show s how t hese object s int er act w it h ot her com pon en t s of a m anag ed sy st em . Poli cy — Builds on t he or igin al policy m odel pr oposed b y DEN and pr ov ides a g en er ic st r uct ur e for repr esen t ing and definin g p olicy r ules, condit ions, an d act ion s. I t also specializes t his t o r ep resent t he specif ic r eq uir em ent of QoS p olicy r ules, con dit ions, an d

act ions. The com binat ion of t h e core m od el and one or m or e com mon m odels pr ov ides t he b asis for a CI M- or DEN- com pliant sch em a t hat can b e boun d t o a sp ecific ap plicat ion .

DEN, an Extension of CIM •

Table of Content s

DEN is t w o t hin gs: • I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

An ex t ension of t he inf or mat ion m odel d ef ined in CI M t hat descr ibes t he phy sical and logical char act er ist ics of net w ork element s and ser v ices, as w ell as policies t hat con t rol t he Pubpr lish Cisco Press over:isionin g an d man agement of net w or k elem ent s an d ser vices Pub Dat e: Sep tem ber 1 1, 2 003

AI SBN: m ap1ping of-1infor 58 705 19 -2 m at ion t o a for m at t hat can be st or ed in a dir ect or y t h at uses ( L) DAP as itPages: s access p rot ocol 11 28 The schem at a f or net w or k int egr at ion defined in t he DEN and CI M specif icat ion s are com plem ent ar y . CI M is pr imar ily concern ed w it h t he m anag em ent of indiv idual com pon en t s in t he con t ex t of an ent er pr ise. DEN is pr imar ily concer ned w it h pr ovid in g m or e d et ail ab out t he net w or kin g com pon en t s of a sy st em , w h et h er it is f ocu sed on t he ent er pr ise, t h e ser v ice The pdator ed bot edit of includ t he b est selling all- inww ork r ef erence p rov ides cover pr ovuider, h ion . This es - descr ibing notone ju stnet net oring k elem en t s and serv ices, b utage alsooft heir essent ial angdan cudt tman ing- edg e t echtnologies. pr ov isionin agement h rou gh t he u se of p olicy ob ject s. The D EN schem a, der ived fr om t h e DEN infor m at ion m odel, for m ap ping dat a in t h e DEN cisemov er v tiew t echn t ialent t o at n et wor ofession alspor at at alles levconcep els, f rom inf ormCon at ion odel o as f of orm su itolog ableies foressen imp lem ion inkaing dirpr ect or y , incor ts nov ice t o ex pert . fr om bot h X. 500 and CI M. er sis include cov erag oferim t ant tsopics like VoI P sand The uNew t ilit y chapt of CI M t hat it defin es geen ic por concept of com ponent t o bEAP e m anaged in an env iron ment . DEN ex t end s CI M b y add in g in for m at ion sp ecific t o net w or kin g t h at is m or e Cov erag e oft he cutinf t ing edge optTh ical n et wor k ing and st or agea dir ect or y specialized t han or m at iont echn t h atologies CI M deflik inees. e DEN m apping p rod uces sch em a t hat defines ent r ies ( along w it h ot her inf orm at ion) t hat can be add ed t o an ex ist in g Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . sch em a t hat r ep resen t n et w or k elem ent s and ser vices. I t also def in es en t r ies t h at r epr esent policy r ules elat ed policy Hand in for m at ion. I n t ern et w or kand in g rTech nologies book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing The D EN in for m at ion m od el and schem a also in cor por at e in for m at ion f r om t he I ETF Policy t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Fram ew or k w ork ing gr oup ( an d p ossibly ot h er w ork ing gr oup s in t he f ut ur e) t h at h as not y et indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . been accept ed by t he DMTF. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

A Brief Introduction to Directories Today , t h e comp ut ing env iron m en t t h at m ust be m anag ed includes n ot only t he com put er s t hem selv es, but also t he n et wor k d ev ices t hat con nect t hem . Ef fect ive net w ork m an agement r eq uir es a v ariet y of inf or mat ion f rom diff erent sour ces, r eflect in g t h e dif ferent needs of t h e •users of t he nTable of kContent et w or and t hs e cur rent st at e of t h e net w ork . Fur t h er m or e, net w ork man agement •m ust b e dist rI ibut ndexed t hr oug hout t he v ar ious m anag em ent point s t hat are used t o man age an d Icont nt e rn et wt h orek ing chnologie s H of a ndbook , Four r ol netTe w or k. Some t his inf ormthatEdit ionion is app rop riat e for st or ing in d irect or ies, w hile ot her pes ar e Inc. n ot . DEN pr escr ibes a m et hod ology t o be used in m odeling net w or k elem en t s By Ciscot ySystems, and serv ices so t hat in for m at ion requ ired for n et wor k p rov isioning and m anagem ent m ay b e im plem ent ed in wh at ever t y pe of r eposit or y is appr opr iat e. This usually inv olv es dir ect or ies, but Pub lish er: Cisco Press it m ay also in volv e ot her t y pes of r eposit ories. Pub Dat e: Sep tem ber 1 1, 2 003

I SBN: 58v705 19 a -2 ph ysically d ist r ibu t ed , logically cent r alized r eposit or y of in fr equent ly A d irect or y 1ser ice-1is 11a28t hat is used t o m anage t h e ent ir e env ir onm ent . Direct or ies ar e com m only used t o chang Pages: ing dat st or e infor m at ion about users, ap plicat ion s, and net w or k r esour ces su ch as f ile ser v er s an d pr int er s. DEN pr ov id es a sch em a t hat adds in for m at ion t o t h e dir ect or y . This schem a in ef fect ext end s t he dir ect or y, en abling it t o cont ain infor m at ion cr ucial f or m odeling net w ork elem en t s and serv ices, as w ell as p olicies t hat cont r ol net w or k elem ent s an d ser vices. Bet t er y et , DEN defin a sch t hat independ en t ofallany dir ing ect or y erence v endor pim t at ion. The ues pdat ed em editaion of is t he b est - selling in-par onet icu netlar w ork r ef rovplem idesen cover age of

essent ial an d cu t t ing- edg e t ech nologies.

Directories and Directory Services Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing

pr ofession als at all lev els, f rom nov ice t o ex pert . This sect ion p rov ides a br ief int r odu ct ion t o dir ect or ies and dir ect or y serv ices. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age WhatCov Is erag a Directory? Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Adir ect or y is used t o recor d in for m at ion ab out a par t icular g rou p of ob ject s. The dir ect ory is not edwtor o kbe generalp ur pose a st, ore. herit,ion it ,isisa aspecial yp e of in for m at ion treposit or y Iint n tend ern et in ga Tech nologies Handdat book FourRat t h Ed com pr tehensive refer ence hat w hose pr im ar y pur pose is t o eff icient ly st or e and r et riev e infor m at ion about obj ect s r elev ant t o enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing a t icular app Mast licat ion ofs,app tpar echnologies. er tor he set t er m conlicat cepions. t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Dir ect or y inf or mat ion is or gan ized as show n in Figur e 53 - 3. Th e gr oups of object s st or ed in a Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, dir ect or y ar e or gan ized in a hier ar ch ical f ashion. Th is is called t he dir ect or y infor m at ion t r ee and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all ( DI T) . Th e DI T consist s of dir ect or y obj ect s—each d ir ect or y object cor r espon ds t o an en t r y in t h e net w or kin g p rof essionals, r egar dless of ex pert ise. DT. Each ent r y can hav e one or m ore at t r ib ut es, and each at t r ibu t e has at least one dist ingusish edobt v alue mayerhav m ore) and opt ionally it ional ondist alues. Reader w ill ain a( itg reat uneder st an ding of LAN andadd WAN n et wnor k ing,ingu p arish t icuedlarvly t h e This st r uct ur e enables y ou t o r et riev e infor m at ion eit h er by specif y in g an ex act set of crit er ia ided t o beon har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov m at ched, or b y specif yin g a m ore general set of cr it eria t hat descr ibes t h e ch aract er ist ics of tions he a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest inf orm at ion t hat y ou ar e seek ing . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Figu -3iciency, . Th e help St r ing u ctt ur of Dmirake e ctmor or ye Iinnf or m at ion- eff icient pr odu ct iv it y an d im rpreov5e3eff he e r eader t elligent , cost decisions for t h eir net w ork s.

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Dist ingu ish ed v alues ar e used t o comp ut e r elat ive d ist in guished nam es ( RDNs) an d f ully The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of qu alif ied dist ing uish ed n ames ( FQD Ns) . The FQDN for an ent r y is bu ilt by t akin g t h e FQDN of it s essent ial an d cu t t ing- edg e t ech nologies. par ent en t r y and append ing t he RDN specified in t he en t ry . Th us, t h e FQDN at any lev el is t he set of RDNs t hat t oget her specif y a pat h fr om t h e r oot of t h e DI T t o t hat par t icular dir ect ory ent r y .Con This is ov show in sFigur e 53olog - 4. ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom cise er vniew of t echn nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Figu r e 5 3 -4 . D ir e ct or y En t r ie s, RD Ns, an d FQ DN s Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. An obj ect in t h e r eal wor ld can b e m odeled as one or m ore dir ect or y ent r ies. Each d ir ect ory en t ry is an obj ect t hat has a set of ch aract er ist ics describ in g t he inf orm at ion car ried by t h e object . These char act er ist ics ar e im plem en t ed as at t rib ut es of t he ent ry . For ex amp le, a User ob ject m ight hav e at t r ibu t es t hat define t h e fir st n ame, last nam e, em ploy ee I D, ph one n um ber, and ot her d at a associat ed w it h t hat user . Each of t h ese at t r ibu t es is com m on t o all in st ances of t he

User class; how ever , t h e sp ecific v alues of at least som e of t h ese at t r ibu t es w ill be dif fer en t so t hat dif fer en t u ser s can b e ident ified. The set of at t rib ut es t hat an en t r y has is d et er m ined b y t he obj ect class of t hat ent ry . Th e obj ect class d ef ines w hich at t r ib ut es m ust b e included ( for ex am ple, v alu es mu st be sp ecified for t h em ) and w hich at t r ibut es m ay be in clu ded f or a given ent r y ( f or ex am ple, t h ey ar e d ef ined in t he sch em a but do not hav e t o b e inst ant iat ed) . The com plet e set of obj ect classes an d at t r ib ut es f or a d irect or y is defin ed as t h e sch em a of t he dir ect or y . •

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•Each at t r ibut Iendex has a sp ecific d at a t y pe t hat may hav e r est r ict ion s qualif ying t h e v alu es of t hat Idat nt earntet ing Te as chnologie s H awndbook , Fourum th Edit ion yw peor(ksuch a st r ing it h alphan er ic char act er s

on ly) . This is called t he syn t ax of t he at tCisco By r ibut Systems, e. I n addInc. it ion, a pr ed ef ined set of m at chin g r ules is d ef ined f or each ent r y t o specif y w het her t h is at t r ibut e is con sider ed a m at ch f or a sear ch . ( For exam ple, g iv en a st r in g, ig nor e t he Pub case of Cisco eachPress char act er in t he st r ing and see w h et h er t his at t r ibu t e' s v alue equals t he v alue lish er: t hatPub is Dat being sear ched for . ) At t ribu t es m ay also be m ult iv alued, b ut t hey do not hav e t o b e. e: Sep tem ber 1 1, 2 003 Finally, all at t r ib ut es hav e ob ject ident if ier s t h at u niquely defin e t hem . These ar e ASN. 1 I SBN: 1- 58 705 -1 19 -2 ident if ier s. Pages: 11 28

Characteristics of a Directory Dir ect or ies hav e fiv e im por t ant char act er ist ics: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The st or age of in for m at ion is opt im ized so t h at it can be read m uch mor e f requ en t ly t han it is w r it t en . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom ice at t oion ex pert Inov nf orm is st.or ed in a hierar chical f ashion. New chapt er sininclude imepor t ant . t opics like VoI P and EAP I nf orm at ion a dir ectcov or yerag is atet rof ibut based Cov erag e ofprcut ing t echn ologies n et wor ingwand or age Dir ect or ies ovtid e aedge un if ied nam espacelikfeoropt allical r esour ces kf or hich st t hey con t ain inf orm at ion. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Dir ect or ies can ef ficient ly dist ribu t e inf orm at ion in a dist r ibut ed syst em t h rou gh r ep licat ion. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables w orm kin g ps rtofessionals o un an d at imper plem em por ar y eint er net w ork ing The f ir st net point ean hat dir ect orties arderst e v erand y good foren m tincont g highv olum search toper echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' sions net wt hork at ions ( such as sear ching an add ress book ) , b ut not good at p er f orm ing oper at at ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . r eq uir e fr equent w r it in g ( su ch as n avig at ing an air line r eser vat ion sy st em ) . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and second speed, tand h is book a com e an d uat p- tr od at ef er ence t o point t he t op aret he essen t oion all The t hir d is point s arplet e som ewh elat ede. rThe second mics eantshat t hat in fort ial m at netrast w orrkin egar ex pert ise. inf uctgurperof is essionals, b ased on rpar entdless - childofrelat ionships. Cont ainm ent , n ot inh er it an ce, is t h e dr ivin g fact or of a good dir ect ory d esign . The t hird p oin t r efer s t o t he f act t hat t he direct or y is comp r ised Reader w ill a g reat der st sanhas dinga of or k ing, ar tinicu h e Th us, of a setsof obobt jectain s. Each of er t heunobj ect setLAN of atand t r ib WAN ut es tnhet atwcont ain tphe forlar mly at tion. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov t he in for m at ion is sp read t hr oug h t he at t r ibu t es of t he obj ect s t hat for m t h e infr ast r uct urided e of on the a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions dir ect or y . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov also is extv end n ott an only n et k ingmconcep t s,mbut also oldlocat er , legacy The erag f our e t hispoint er y ed im por t . Ittomnew eans t hwor at com on in for at ion cant obe ed and sh ared syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm s inenwcin hich by d iff er ent dir ect or y client s becau se each applicat ion can use t h e same met h od ofent r efer g pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease an obj ect . A unif ied nam espace enables net w or k elem en t s and serv ices t o be seam lessly pr pr ov effof iciency, ingsuch t he ras eader mor eions, in t elligent , cost intodu egr ct ativ edit yw an it h dotim h er t ypees in for mhelp at ion, userm s, ake applicat and ser v ers.- eff icient decisions for t h eir net w ork s. The f inal p oint is cr it ical for building an inf orm at ion inf rast r uct ur e. The dir ect or y ser v er has t h e capabilit y t o con t r ol w hat infor m at ion get s dist r ibut ed w hen and t o w h at ot h er n odes in t he syst em .

What Is a Directory Service? Adir ect or y ser v ice st or es and r et riev es in for m at ion f r om t he direct or y on behalf of one or mor e aut h or ized users. Dir ect or y serv ices are b uilt t o pr ov ide cer t ain t y pes of app licat ion- specific inf or mat ion . How ev er , m ult iple d ir ect ory ser vices can shar e t h e same dir ect or y . For ex am ple, t hin k of t w o t elephone e Pages p hone •book s, a W hit Table of Content s b ook and a Yellow Pages p hone b ook. Bot h pr ovid e phon e num b er s, ent way . Th e Whit e Pag es phon e book enab les y ou t o f ind t he t elephon e num b er of •bu t in a d ifferI ndex ileTetchnologie he Yellow ph onethb ook en ables you t o look up cat eg or ies of inf or mat ion Iantpeer rnson, et w orwh k ing s HPages a ndbook , Four Edit ion and r et riev e m ult iple ph one nu m bers. By Cisco Systems, Inc.

A d irect or y can b e used t o im plem ent bot h of t hese ser v ices. I n t his exam p le, t he dir ect or y Pub lish er: ain Ciscot he Press w ould cont d at a m odel d escrib in g t he d if fer en t t y pes of u ser s and serv ices t hat y ou ar e SepTher tem ber 003 ually t w o d iff er ent dir ect or y ser v ices, one for p rov iding access t o int erPub estDat ede:in. e 1ar1,e2 act Whit e Pages a -1 and I SBN: 1- dat 58 705 19 -2one f or Yellow Pages dat a. Howev er , t hey can u se t he sam e dir ect or y —t he dat a mPages: odel 11 of28t he Whit e Pages ser vice is simp ly ex t ended t o su it t he mor e com plex needs of t he Yellow Pages ser v ice. This ex am ple also show s t hat dir ect or y ser vices are usually r est r ict ed t o operat e in a par t icular w ay . For ex am ple, y ou can 't giv e t he t elephon e num ber of a user t o a Whit e Pag es ser vice an d ( easily ) g et t he cor r esp onding user . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Current Uses of the Directory Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom ice o ex pert A t radnov it ion al tdir ect ory. ser vice pr ov ides a m eans f or locat ing and ident ify ing users and available r esour ces in a dist r ibut ed syst em . Dir ect or y ser v ices also p rov ide t he f ound at ion f or add in g, New er ing, s include e of im por t g ant opics likepon VoIen P tand m odify ing ,chapt r em ov renamcov ingerag , and m anagin sy tst em com s w itEAP hou t disr upt in g t he ser v ices p rov ided by ot h er sy st em com p onent s. Today ' s dir ect or y ser v ices ar e u sed t o d o t h e Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age follow ing : Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . St or e inf orm at ion abou t sy st em com pon en t s in a dist r ibut ed m anner . The d irect or y is I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat r ep licat ed am ong sev er al ser ver s so t h at a user or ser v ice n eedin g access t o t h e dir ect or y enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing can quer y a local serv er for t he inf or mat ion . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu stSup ry . por Lear how t o sear incorch por int er w oras kinb gy tat echn olog a ple, LAN/"WAN ir onm t n com m on in at g e need s, net su ch t r ibut e (ies for in ext oam Fin d tenv h e ph oneent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit nu mb er for Jam es Sm it h" ) and by classif icat ion ( f or exam ple, " Find all color pr int er s ony,t he and speed, t h is "book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all t hir d floor ). net w or kin g p rof essionals, r egar dless of ex pert ise. Pr ovid e imp ort ant in for m at ion t o enable sing le- u ser logon t o ser v ices, r esour ces, an d Reader sw ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e app licat ions. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r angae locat of intionegr in al dependent sy st em s and servofices, cludr at ingiondet descr ipt ion.s,Not reveiew En able point admininist anailed d m an agement t hatquest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . adm inist r at ive t ools do n ot h ave t o be cent r ally locat ed an d m anag ed . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in ga at ompor e r ealist pict ur eaccess. of t he Modificat real- w or ld n etm wade or k ing enyvirreplica onm ent Replicat e dat r ovide conicsist ent ions t o an ofs tin h ew hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr dir ect or y ar e p rop agat ed arou nd t he n et wor k so t hat any app licat ion accessin g t h eease pr odudir ct iv it yoran d im ovee sees eff iciency, r eader e in t elligent , cost - eff icient ect y an ywpr h er consisthelp ent ing in fort he m at ion af tm erake t he mor ch ange is p r opagat ed. decisions for t h eir net w ork s.

Motivation for DEN and Intelligent Networking Ther e ar e t w o m aj or pr oblem s w it h p re- DEN d ir ect ory ser ver s and serv ices t hat h ave pr ev ent ed

t hem f r om being used f or int elligent net w ork ing. The f irst is t he incapab ilit y for h et er ogeneous dir ect or y ser ver s t o r eplicat e dat a w it h each ot her . The p rob lem is t hat t he LDAP p rot ocol d oes not pr ov ide for t his, and dir ect ory v endor s h ave im p lem ent ed t heir ow n p rop r iet ar y r eplicat ion m ech anism s. Som e dir ect ory ser vice v en dor s use a for m of sy nchr onizat ion, w h ich is a t ool t hat can read infor m at ion fr om an ot her v en dor 's d irect or y ser v er and t r anslat e t hat infor m at ion int o a for m at t hat can b e used b y t he serv er per for m ing t he sy nchr onizat ion. How ev er , t her e ar e no sy nchr onizat ion st and ard s ( each w or ks diff er ent ly ) , an d t h er e ar e a • Table of Content s v ariet y of lim it at ions w it h each im plem ent at ion . I t shou ld b e not ed t hat t his p rob lem is cur r ent ly • I ndex being w or ked on in t h e I ETF, in t he LD AP Du plicat ion and Upd at e Pr ot ocol w ork ing gr oup I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion ( LD UP) . LDUP h as defined an infor m at ion m odel t hat has b een used t o gu id e t he developm ent of By Systems, Inc. a rCisco eplicat ion p rot ocol t hat is in t h e pr ocess of b eing st and ar dized . This w or k shou ld hop ef ully be fin ish ed by t he end of 200 0. More in for m at ion ab out LDUP can be ob t ained at ht t p: / /lish ww . iet f .or g / ht m l. ch art er s/ ldup- ch art er . ht m l. Pub er:wCisco Press Pub Dat e: Sep tem ber 1 1, 2 003

The second pr oblem is t he lack of st and ard izat ion in r epr esent ing inf orm at ion . For ex am ple, I SBN: 1- 58 705 -1 19 -2 t her e ar e m any com pet ing w ays for r epr esent in g g en er ic user inf orm at ion . I n ad dit ion, t here is a Pages: 11 28 t endency t o desig n applicat ions in a st ov ep ipe f ash ion . This m eans t hat ap plicat ion s t end t o r ep r esent dat a accor ding t o a set of nam ing conv en t ions an d st r uct ur es t h at m ak es m ost sense t o t heir use. Alt houg h t his is beneficial f or a sing le applicat ion, it mak es it h ar d f or dif fer en t app licat ions t o shar e and r euse dat a. This pr oblem is illust r at ed in Figur e 53 - 5. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r e 5 3 -5 . I nt egr a t i on of St ov e pipe Appl ica t i ons I s Ve r y Di ff icul t Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e As in Figur e 53 t h e inv pr olifer ionndam of d ispar dat a st or inf es,oreach bu iltis tpr o ov supided por ton a harcan dw arbe e, seen pr ot ocols, and ser- 5, v ices olv edat . Fu ent alatt eech nology mat ion par icular appelicat ion' s al n eeds, m ak es inserv t egrices, at ioninvclud ery ing diff icu . Thedescr f irst ipt pr oblem is iew t he quest ions a b rt oad r ang of int egr sy st em s and detltailed ion s, rev cont usecept of applicat ionic r ep ies.and This each r eposit willstdudy ef ine t o eninu su in regcon comp r eh en specif sion and r etosit en tor ion, adisditbecause ional r esou r ces f or fuory rt her . som e of et he sam eext dat a using erent st or age andk ing n aming r ules. Thisalso causes syn ron izat ion Cov erag is also end ed n otdiff only t o new n et wor concep t s, but t o old er ch , legacy pr oblem because each cop y icofpict t heurdeatof am u strealbe uwpdat t he sam t im e; becau hey syst em s,s pr ovid in gnow a m or e r ealist t he or ld ed n etat w or k ing enevir onm ent s insewthich ar e in diff er entoper for at m e. at sTools and rand epr esent at ion s,f or how erizing , t hissyst is qem uit eper harfor d.mSecond r esult s in pr of essionals gu id elines optev im ance w,illit incr ease dif fer en t vitiew s dofim t he sam e dat a. Th ehelp fin al in t egrmat ion.mor I f all licat ions are usin g pr odu ct iv y an pr ov e eff iciency, ingissue t he riseader ake e inapp t elligent , cost - eff icient pr iv at e v erfor sions t hewsam e d at a m odel, how w ill t hey exchan ge d at a? Not e t h at t his also decisions t h eirof net ork s. pr eclu des t he capab ilit y of applicat ions t o sh are and r eu se t he ot her s' dat a. Alt hou gh t his w as a pr oblem, a w or se pr oblem w as t hat t her e w as no st andar d at all for r ep r esent ing net w or k elem ent s an d ser vices befor e DEN. Ther ef ore, D EN p rov ides t w o imp ort ant benefit s:

Net w ork elem en t s and ser v ices ar e r epr esent ed in a st andar d w ay, en abling div er se app licat ions t o shar e and r euse t he sam e dat a. All obj ect s of a m anag ed env iron ment ar e r ep resent ed as object s. This enab les t h e dif fer en t t y pes of ent it ies t hat m ake u p a m anaged syst em t o be t r eat ed in t he sam e w ay . This pr ov ides a u nified way of repr esent in g in for m at ion about diff erent t y pes of ent it ies. •As an exam ple, Table Content t hof ink of t hes cu rr ent w ay of pr ovid in g unif ied net w or k m anagem en t . You m ight •use HP/ Op enIview ndex f or m anagin g t he dif fer en t ent it ies in an ent er pr ise, and one or m or e CiscoIspecif nt e rn et or k ing Teions chnologie s H aendbook , Four iongum ent t hat t hey ar e r unn ing on W in dow s NT) for icwapplicat ( assum f or t he sakthe Edit of ar conf ig ur ing and pr ov isioning t h e Cisco dev ices in t he ent er pr ise net w ork . Th is is a p rob lem By Cisco Systems, Inc. because t hese t w o t yp es of ap plicat ion s need t o shar e dat a. But t his is v er y h ard , if not im possib le, b ecause of t h ese r eason s: Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

The I SBN: ap1-plicat 58 705ion -1 19 s-2hav e dif fer en t w ay s of r ep r esent ing t he sam e inf or m at ion ( b ecause t h ey ar e bu ilt diff erent ly ) . Pages: 11 28 The ap plicat ion s ar e r unn in g on d iff er ent plat for m s. The ap plicat ion s ar e coded in dif fer en t lang uages. The uDif pdat ed edit ionint ofert he b est - selling all- in-ap one netion w ork ferent user faces exist f or each plicat . ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Not e t h at , in general, wr it ing API s doesn' t w or k . This is n ot only b ecause of t h e pr eviou sly st at ed r easons, b ut also becau se a giv en API is usually a r eflect ion of t h e int er nal f unct ionalit y of t h e Con ciseThis ov err eq v iew t echn t o n et wor k ingbeprfam ofession alshatt hall lev els, f rom app licat ion. uirsesoft he devolog elopies er essen t o havt ial e access t o and iliar wit e oper at ion of nov ice t o ex pert . t he applicat ion t o be in t eg r at ed . This clearly is n ot t h e usual case—and even if it w ere, each t im e t hat t he applicat ions being int egr at ed ch ange, t he API s w ould hav e t o ch ange. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP DEN solves t h is by def in ing a st and ard w ay t o r ep resen t inf or m at ion . By u sing t echniq ues su ch Covdev erag e ofercut t ingenedge e opt icaled n etinwor k ing st or ageit t o anot her as XML, elop s can cod et echn t heir ologies dat a aslik r epr esent D EN anand d can ship app licat ion on a dif fer en t p lat for m . That applicat ion can t h en decode t h e DEN dat a and use it Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . dir ect ly in it s ow n int er face. Clearly , t h is is a v ery p ow er f ul concept : I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables r ofessionals t o un derst and ap anplicat d im plem Thenet adwmorinkin ist rgatpor need s t o lear n on ly one ion . en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu stAPI ry .sLear por e intt er w orwkin t echnch olog ies of in teach o a LAN/ WANion. env ir onm ent . donn't how hav et ot oincor b e bu iltatonly o net br eak it hg each ange applicat Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h isb book is a and com plet t o- dap atplicat e r ef er ence o t heenab t op les ics b t hat essen Dat a can e r eu sed shareedanbdetuwp-een ion s, w thich est -are of - br eed t ial t o all net w or kinlicat g p ions rof essionals, egarher dless of ex pert.ise. app t o w or k troget seam lessly Reader sw ill obt ain a g reat erenun ansding of LAN et w k ing, t icu larplicat ly t h eion s DEN t her efor e enables dif fer t der v enst dor t o build diffand erentWAN net wn or k or elem entpsaran d ap har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is ov ided t hat can com m un icat e w it h each ot h er . Th is en ables var ious t yp es of sy st em s as w ellpras net w on ork a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest elem ent s t o be equ al par t n er s in imp lem ent ing an d r eact in g t o decision s m ade t h rou ghou t t hions e tnet o en suked re con w or envcept ir oncomp ment .r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Distributing Intelligence in Networked Applications pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Rap id I nt er net g r owt h ov er t he past sever al y ear s h as creat ed t he n eed for m or e r obu st , scalab le, an d secur e net w or king serv ices. Resident ial cu st om er s desir e r ich m u lt im edia ser vices, such as dat a and vid eo. Cor por at e cust om er s ar e look ing t o t elcos and ser v ice pr ovider s f or pow er ful yet aff ord able ser v ices. User s w ant a r eliable, easy - t o- use, fr iendly ser vice. A f un dam en t al shift t ow ar d band wid t h- int ensiv e and isoch ron ous net w or k app licat ions has

occu r red. Com mu nicat ion p rob lem s ar e n o long er j ust a f unct ion of band wid t h. Rat her, it is incr easing ly mor e im por t ant t o und er st and t he need s of diff erent t y pes of t r aff ic flow ing in t he net w or k and t o desig n a net w or k t hat can accom mod at e t hose n eeds. Fur t her m ore, if r esou rces becom e scar ce, t hen an eff icient w ay t o allocat e t h ese r esou rces accord in g t o t h e business r ules of t he com pan y is r eq uir ed . DEN play s a cr it ical r ole in solvin g b ot h of t hese pr oblems. Th e infor m at ion m odel is used t o descr ibe t he f unct ion and needs of t he diff er ent applicat ions u sing t h e net w or k. This t r anslat es • Table of Content s int o a set of t r af fic f low s t hat will u se t he n et w or k . The D EN p olicy m odel can be u sed t o • I ndex t r anslat e f rom business t er m s t o a f or m t hat is independ en t of an y one p art icular d ev ice. This I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion can t hen b e used t o m ap t o d ev ice- specific pr ot ocols and m ech anisms. By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 1- 58 705 -1 19 -2 DENI SBN: Policy Model Pages: 11 28

The d esir e t o allocat e r esou rces accord in g t o t h e business r ules of t he com pany is a crit ical r equir ement . The D EN p olicy m odel d ef ined a cont inu um of policies, each opt im ized t o r ep r esent diff er ent set s of in for m at ion. For exam p le, a business goal m ight be ad min ist r at or - def in ed , w hich mak es it d ev ice- and m echan ism The independ u pdat ed en tedit . Asion an of ex tamp he ble, estconsider - selling allt h is in-business one net wr ule: ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. IF Con ov er v iew of t echn User is cise sub scr ibed t os gold ser volog ice, ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . THEN allow use of Net Meet in g and New s include erag e of im por t ant t opics like VoI P and EAP pr ov ide chapt pr em er iu m dat a sercov v ices ENDI F Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age This is a per fect ly valid business r ule, but it d oesn 't say how t o configu r e t he d ev ices. Aut hhored Syat st ems, w or ldw ide leader in net I t d oes, ow evby er,Cisco say wh serv ices sh ould be allocat ed .w or king f or t he I n t er n et . I nThis t ernbetusiness w or k in gr uTech nologies booked , Four t h Ed itconf ion , igur is aatcom refer le need s t o b Hand e t r anslat t o device ion pr ruehensive les so t hat t heence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing net w or k can sup por t t he bu sin ess p olicies of t he or gan izat ion . On e su ch t r an slat ion t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing m ight be t h is: indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and I F speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kinPAddr g p rofess essionals, r egar Sou r ceI = 17 2. 3. 12 8.dless 0/ 15 of ex pert ise. THEN Reader w ill obt g reat Mark sVoice w itain h EFa an d er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Mark Dat a w it h AF11 aENDI b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions F t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed t he n otser only t o new n et wor ing concep butt oalso t o old er , legacy This r ule st ar ts m app ing vices sp ecified in kt h e bu sinesst s,r ule a f orm t hat can syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm ent s in w hich be ap plied t o a d ev ice. This r ule is dev ice- ind ep en dent in t h at it can app ly t o m any prdif offer essionals oper e. ices. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease en t t y pes of at dev pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions t h eir ork The n ex t for st ep is t onet mwap t hs.is t o a for m t hat can be im plem en t ed in a d ev ice. This m ean s t hat w e need t o m ap t he p rev ious r ule t o a f or m t hat ident ifies t h e device m ech anism s t hat m u st be cont rolled. Th er e ar e sev er al dif ferent f orm s of t h is, each app rop riat e for d if fer ent act ions:

Con figu re com pon en t so t hat it can b e used t o condit ion for w ar ded t r aff ic Con figu re com pon en t so t hat it can act on t raf fic d irect ly Tr igger act ion based on a n et wor k or sy st em ev ent ( such as lin k failur e) This set of p olicy r ules can now b e t r anslat ed int o ( for ex am ple) a set of devicespecif ic CLI com m and s. •

Table of Content s

• The ad van t age I ndexof t h is appr oach is t hat it can be u sed as a r eusable t em plat e. That is, I nt e rnead et w or Te chnologie a ndbook Four th Editsion inst ofk ing t ry ing t o perf sorHm t hese, m apping for

each int er face of each dev ice in t h e net w or k, a set of t em plat es cont r olled by p olicy can be d ev eloped so t hat t he d ev iceBy Cisco Systems, Inc. independ en t r ules can be separ at ed f r om t he d ev ice- d ep en dent ru les. Th e Policy Fram ew or k w ork ing gr oup of t h e I ETF is t ak ing ex act ly t his ap pr oach f or t h e con t r ol Pub lish er: Cisco Press and pr ov ision in g of QoS; see ht t p: / / w w w . iet f .or g / ht m l. ch art er s/ policy - char t er .h t m l Dat e: Sep tem ber 1 1, 2 003 forPub m ore in for m at ion. I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Use of the Directory in Intelligent Networking A d irect or y ser v ice can be u sed t o st or e an d r et r iev e m uch of t his inf or mat ion . This is b ecause of u pdatin edg edit of trhe b ests:- selling all- in- one net w ork ing r ef erence p rov ides cover age of tThe he follow fourion main eason essent ial an d cu t t ing- edg e t ech nologies. 1 . Con A d irect cise or ovyerisv iew a n at s of ur al t echn pu blishing olog ies m essen ed iutm ial, capable t o n et worofk ing sup por pr ofession t ing a hig alshatn um all ber lev els, of r feads rom as novwice ell tas o ex allow perting . arb it rar y in for m at ion t o be st or ed an d ret r iev ed. Th us, t her e ar e no r est r ict ions on t he in for m at ion it self; t his pr ov ides inher ent ex t ensibilit y for accom mod at ing Newit chapt im por t ant t opics like VoI P and EAP add ion al er asswinclude ell as ncov ew erag in foremof at ion. erag e ofarcut ingde edge e opt ical worin k ing st or 2 . Cov Dir ect or ies e tthe f act toechn st anologies dar d forlikcont ain in gn et user for mand at ion anage d ot her t y pes of inf orm at ion, and dir ect or y - enabled n et wor k ap plicat ion s r eq uir e user , net w ork , an d ot h er Aut h ored by Cisco Syorm st ems, leader netadv w orant king t erorm n et .at ion abou t t y pes of r esour ce inf at ionw tor o ldw be ide int egr at ed.inThe agfeorist he t hatI ninf net w or k r esour ces, elem en t s, and ser v ices ar e not only colocat ed , bu t t h ey ar e r epr esent ed I n t ernas et w or kalinobj g Tech Hand book , Four t hesent Ed it ion , is a com pr ehensive refer enceapp t hat equ ect snologies t h at h ave a com mon r epr at ion. This enables t h e diff erent licat ions enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w t hat w ant t o u se and sh ar e t his inf or mat ion t o access a single r eposit or y. This gr eatork ly ing t echnologies. t he t er s, con cep t echn simp lif iesMast t he er design ofmt he ov er allt s, sy st em. ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com it hies new an at de u pdat ed chapt erat s ion on secur it y ,kst or age, ical net k inhg,orscalabilit 3 . plet Dir e ectwor facilit fin ding inf orm w it hout now ing t opt he com pletweorpat n am e ofy,t he and speed, is book a in com an dAudir p- tect o- doraty eser r efver ence t o tehe op ics t hating areser essen t o as all obj ect tthhat has tis h at forplet m ateion. ice is mor t htan a nam v ice,t ial such net w or kin gAp rof egar exhpert DNS. dir essionals, ect or y servrice endless ablesofbot t heise. sear ching and t he ret r iev al of n amed inf orm at ion. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har pr ot and bser ices tinv olv edt.oFu entem al tsech nology inf or matmion is prtov 4 .dwAarde, irect or ocols, y can also e vused o point otndam her syst t hat cont ain infor at ion; hisided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions pr ov ides a single p lace wh er e ap plicat ion s can g o t o find inf or mat ion . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Challenges ofatCurrent Directory pr of essionals oper e. Tools and gu id elines fServices or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Cu rr ent dirfor ectt or y ser ices echn olog y is not desig ned t o m eet t he ev er - incr easin g d em and s of decisions h eir netvw ork ts. t oday ' s pub lic and pr ivat e net w ork applicat ions. This is b ecause cur r en t d irect or y ser v ices w ere bu ilt m ainly t o accom m odat e adm inist r at ive need s. Direct or ies u sed in t his f ash ion t ak e t h e for m of du mb w ar ehouses, wh er e t h ey are sim ply u sed t o st or e simp le infor m at ion. The dir ect or y m ust b e t r ansfor m ed f r om a d um b war ehou se t o an aut h orit at iv e, dist r ibut ed, in t elligent r ep osit or y of inf or m at ion f or ser v ices an d ap plicat ion s. View ed in t h is w ay, t he dir ect ory is one of

t he foun dat ions for an int elligent in fr ast ru ct ur e. Band wid t h- int ensiv e and isoch ron ous net w or k app licat ions requ ire t hat t he dev ices t h at lie on a pat h t h rou gh t he n et wor k b et ween sou rce an d end dev ices b e con figu r ed app rop riat ely if t hey ar e t o fun ct ion pr op er ly. This conf ig ur at ion is oft en dy nam ic, t ak in g p lace on d em and w hen a par t icular user logs on t o t he n et wor k f r om any of a num b er of p ossible locat ions. On ly w hen m anagem ent in for m at ion ab out t he u ser s, net w or k devices, and ser v ices inv olved is av ailab le in a sing le, au t hor it at iv e locat ion is it possible t o act ually m anag e t his new class of app licat ions. •

Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

An Overview of DEN This sect ion d ef ines t he p rob lem dom ains, infor m at ion m odel, and usage f or int egr at ing net w or ks w it h d ir ect ory ser vices. Dir ect or y - en abled n et w or k ing is a design philosoph y t hat uses t he DEN sp ecificat ion t o m odel com pon en t s in a m anaged env ir onm ent . These com pon en t s •include net w ork Tabled of evContent ices, h sost syst em s, operat in g sy st em s, m anag em ent t ools, and ot her •com ponent s Iof ndex a syst em t o be m anag ed . All t hese com ponent s use t he d ir ect or y ser v ice t o do It he nt e rn et w orin k ing follow g: Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish infor m at ion about t hem selv es Pub lish er: Cisco Press Pub Dat e: Sep tem 2 003ces Discover ot hber er 1r 1, esour I SBN: 1- 58 705 -1 19 -2

Ob t ain11inf Pages: 28or m at ion ab out ot her r esour ces DEN is t w o t hings:

1 . uAn exed t ension CItM The pdat edit ionofof he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. 2 . A m ap ping of infor m at ion t o a for m at t hat can be st or ed in a dir ect or y t h at uses ( L) DAP as it s access p rot ocol Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The f ollow in gt osect ions. pr ov ide an ov er v iew of building int er oper able net w or k- en abled solut ions nov ice ex pert and t h e benefit s t h at D EN can br ing. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge Networks and DEN

t echn ologies lik e opt ical n et wor k ing and st or age

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Adm inist r at ive n eeds and t he t ools t hat ser vice t h em hav e ev olv ed as d ist r ibu t ed sy st em s hav e I n t erned. et wToday or k in g' sTech nologies Four t h Edtito ion , iside a com refer t hat it y evolv dir ect or y servHand ices book wer e, designed p rov centpr r alehensive m anag em entence of secur enables kin r ofessionals o un derst d imsm plem cont por arivyely int lar er net and contnet act winorfor mgatpion in a net w tork wit h a and relatan iv ely all en nu tmb er em of relat ge w ork ing t echnologies. Mast t he t er em m s,ent conhas cepbt s, t echn used in t oday net wwork com put er s. Net w orer k m anag een t he ologies, p rov incean ofd mdevices or e specialized t ools,' seach it hing it s indu ry . m Lear n how o incor por ion at e m intanagem er net w or kinhgast echn iesessed in t o a WAN env irht onm ow n st infor at ion st or te. App licat ent beenolog ad dr asLAN/ an af t er t houg whent en .it Combeen plet e add w it hressed new an u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, has atdall. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Ob gence on rtegar he stdless r uct uof re ex and repr nettwaining or kin gconv p roferessionals, pert ise.esen t at ion of in for m at ion in any one t y pe of r ep osit or y ( let alon e across all t he dif fer en t inf or mat ion st or es t hat are applicable t o net w ork ing) Reader s wvill a g. reat un der an en ding of LAN et w or k m ing, p arem t icu lartly t h ehav e has been er obt y d ain if ficult Theerr esult isstan vir onm entand in wWAN h ich n v er t ical anag ent ools har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided eon pr olifer at ed . Lack of int eg rat ion and t h e sheer com plexit y of t he t ools t h em selv es has becom a a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions bar ier t o t h e deploy ment of new ap plicat ion s. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Adm inister at s need a lev er nt heir net w orconcep ks t hatt s, is but cu rralso ent lyt ou nav ailab le. Cov erag isor also ext end edeln of ot cont only r tolo ov new et wor k ing old er , legacy St r eaming ult im use p ublic netur weorof k st he andrealt he watort en it yenconcern apidly syst em s, prm ovid in gedia, a m or e rof ealist ic pict ld dant n et w secur or k ing vir onms, entand s inr w hich gr ing user comm ies prand esent r emend pr ow of essionals oper atue.nitTools guaidtelines f orous optchallenge. im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Sim ply m anagin g ind decisions for t h eir netividu w orkal s. dev ices is n o long er su fficient . Net w or k adm inist r at ors need t o defin e and m anage policies t o con t rol t he n et wor k an d it s resour ces in a dist ribu t ed y et log ically cen t r alized m anner . I n general t er m s, policies d ef ine w hat r esour ces a g iv en con su m er can use in t he cont ex t of a giv en app licat ion or serv ice. The incapab ilit y t o easily m anag e policies is a signif icant bar r ier t o d ep loy m ent of leading - ed ge d ist r ibu t ed app licat ions. A consu mer is a user , an ap plicat ion , a ser vice, or anot h er user of resour ces.

Defin in g and man aging policies r equ ir es a com m on st or e of w ell- defined infor m at ion about t he net w or k and it s r esou rces—user s, app licat ions, d ev ices, p rot ocols, and m edia—and t h e r elat ion sh ip s am ong t hese elem ent s. This is in for m at ion ab out t he n et w or k as w ell as t h e inf orm at ion t r adit ionally v iew ed as defin in g t he net w or k ( f or ex am ple, r out ing t ab les) . At issue is w her e t o st or e policy and ot h er in for m at ion t hat need s t o b e applied acr oss com ponent s in a way t hat m ak es it usable b y a br oad r ange of con su mer s. •

Table of Content s A scalable, secur e d ir ect ory ser vice t h at pr esen t s a log ically cen t r alized view of p hy sically •dist r ibut ed infor I ndex m at ion is t he log ical p lace t o st or e t he m et ainf orm at ion essent ial t o cr eat ing an d Im ntanagin e rn et w or Tetchnologie H a ndbook , Four th Edit g kaing nex - gener ats ion n et w or k . The spion ecificat ion for t h e int egr at ion of dir ect or y ser v ices and By Cisco netSystems, w or k serInc. v ices d ef ines t he in for m at ion m od el and schem a t o m ake t his possible.

Tw oPub oflish t her: e pr om ises of DEN ar e t h ese: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 19 -2s of st oring d at a in a com m on r eposit or y To d ef ine a m-1ean Pages: 11 28

To p r ovide a w ay f or applicat ions t o be capab le of t ak in g ad van t age of d at a m anag ed b y ot her ap plicat ion s. This r epr esent s a f und ament ally n ew w ay of t hink ing abou t net w or k m anagem ent applicat ions, along w it h applicat ions t h at seek t o lever age t h e pow er of t he n et wor k . On e exam ple of t h is is t o The u pdat edit ion nofettwor he bk est - selling all- innet w ork r ef erencet hat p rovuses ides DEN. cover Iage com par e t ed r adit ional m anag em ent w itone h n et wor k ming an agement n a of essent ial an d cu t t ingedg e t ech nologies. t r adit ional net w ork man agement syst em , each d ev ice in t h e net w or k is r ep resen t ed on ce. How ev er , each dev ice h as det ailed conf igur at ion infor m at ion t hat is st ored not in t he net w or k m anagem ent ov sy er st em , but eit her t hies e app licat iont oit nself or kanot dat a st als ore.atThall e lev roleels, of f rom Con cise v iew s of in t echn olog essen t ial et wor ing her pr ofession por t r ay in g t he d ev ice in t h e net w or k m anagem en t sy st em is t o enable t he user t o lau nch a nov ice t o ex pert . par t icular m anag em ent applicat ion t hat is focused on one or m ore asp ect s of m anag ing t hat dev ice. Th us, t he wor k mcov anag eme ent syst pr tov ides like a com p lace New chapt er ns et include erag of im porem t ant opics VoImPon and EAPt o r epr esent t he dev ice, b ut n ot t o st or e it s inf orm at ion. This m akes in t eg rat in g ap plicat ion s and shar ing inf ormCov at ion bet en t ap plicat ion s diff lt , ical if not erag ew ofeen cut tdif ingferedge t echn ologies likicu e opt n etimp worossible. k ing and st or age This isAut v er y diffby er ent t han y-ldw based roach t hatw or uses al pur p ose h ored Cisco Syast direct ems, or w or ide app leader in net kingDEN. f or t The he I nf und t er nament et . of DEN is t o pr ovide a com mon , un ify ing in for m at ion reposit or y t hat is used t o st or e dat a and I n torm inf ern et atwion or kabou in g Tech t t h enologies dat a ( such Hand asbook met,adat Foura)t hf or Ed m it ion ult ,iple is aapp com licat pr ehensive ions t o shar refer e an ence d u tse. hatFor enables exam ple,net consider w or kin ga pnet r ofessionals w ork man tagement o un derstsyst andem an d u sing im plem HP/en Opt en cont view emrpor un ning ar y int onerHP/ netUX. w ork ing t echnologies. Sup pose t hat Mast it d iscov er t he er st aer new m s, con r outcep er ,t s, one t echn t hatologies, it doesn't an dhav devices e an y used infor minatt ion odayon ' s in netitw s ork int er ing nal induab dat stase. ry . Lear Bef ore n how D EN, t o incor t h e only por at solut e intion er net for wt or hekin netgwt echn or k adm ologinist ies in r at t oora wLAN/ ouldWAN be t oenv puirrchase onm ent . Com hplet anot er eman w itagem h newenan t tdool u pdat t hatedsuchapt ppor ter s st he onnew secur r out it y ,erst. or Thage, en , ever opt ical y t im net e wt hat or k in r out g, er scalabilit m ust by,e and m anaged, speed,t he t h isn et book w or is k ad a com min ist plet r at e or anwd ou u pldt ohav d at e et or ef get er ence up and t o ch t heange t op ics cont soles. hat areOfessen cour tse, ial t his o all netonly is w or kin t h egbeginn p rof essionals, ing of t her egar p robdless lem s of b ecause ex pert ise. t h e new m anag em ent t ool pr obab ly has it s u ser int er face and r un s on a dif fer en t p lat for m . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har h Wit dwDEN, ar e, pr t hing ot ocols, s hav e and t heser pot v ices ent ial invt oolvbe edseam . Fu ndam less. ent I 'll al u se t ech annology ex ampinf le or fr om mat tion h e is 199 pr9ovN+ ided I shon ow a bAt in r oad lant ra, ang w her e ofe int HPegr anal d Cisco sy st emdemon s and st serv rat ed ices, t his. in clud Boting h HP det and ailed Cisco descr suipt ppor iont s,DEN, rev iew w h ich quest ions t o en su rea con enables set cept of com comp m onr eh man en sion agem and en tr inf et en or tmat ion,ion anddef adindit edional b y t he r esou CI Mr ces andf or DEN fu rtsther andstard udys .t o b e Cov eragged exchan e is( not alsoe ext t h at end m ed or endet ot only ailedt o infnew or mat n etion worcan k ing beconcep ex ch anged t s, butbyalso subtclassin o old erg, tlegacy hese syst st andar em s, d sprand ovidusing in g a tm hem or e as r ealist t he ic basis pict tur o er ep of resen t he realt Ciscow or ld specif n et w icor prkoduct ing ens vir anonm d serent vices) s in .wThis hich pras w of essionals don e by hoper avinat g e. t h eTools HP/ Openv and guiew id elines agentf or m essage opt im izing t h e Cisco syst em m anagem per for m ent anceagent w ill incr , askease in g for tpr heodu DEN ct ivdescr it y anipt d ion im profovt he e eff d ev iciency, ice. Thhelp is infor ing m t he at ion r eader w as m encoded ake morin e in XML t elligent and w, as cost shipp - eff icient ed t o decisions HP/ Op en view for t hoveir er net HTTP. w orkThe s. com binat ion of XML and HTTP en su red t hat no plat f orm - and langu age- specif ic pr oblems got in t h e w ay. How ev er , t he r eal b onus is t hat t he nat ive Cisco r out er d at a is used t o pop ulat e t he HP/ Openv iew scr een. Th is has t h e follow ing imp licat ions:

The ad m in ist r at or has t o lear n only one user in t er f ace. The sy st em is inher en t ly ex t ensible. Becau se D EN is t heir com m on int er face, it can dy nam ically accom m odat e new pr oduct s as lon g as t hey ar e descr ibed in D EN. No com plicat ed API s m ust be bu ilt . Add it ion al pr odu ct s t hat w ant t o shar e d at a can do so. •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Directory Service and Network Management By Cisco Systems, Inc.

Net w ork elem en t s t y pically h ave a dy nam ic st at e an d a per sist ent st at e. Dyn am ic st at e is w ell lish er: by Cisco addPub ressed n etPress wor k m an agement pr ot ocols. Howev er, t here is no st an dar d w ay t o describe Pub Dat e: Sep tement ber 1st 1,at 2 003 and st or e per sist e. Mor eov er, ex ist in g t ools and app licat ions f ocus on m anagin g I SBN: 158 705 -1 19 -2 indiv idual net w or k elem en t s r at her t h an t he ent ir e net w or k. The DEN and CI M specif icat ions defin ePages: a st and ar d schem a f or st orin g p er sist ent st at e an d an inf or mat ion m odel f or descr ibing 11 28 t he relat ionships amon g ob ject s r ep r esent ing users, ap plicat ion s, net w or k elem en t s, and net w or k ser v ices ( see Figur e 53 - 6) . Net w or k- m an agement pr ot ocols ( such as SNMP, CMI P, and HMMP) ar e used t o t alk t o t he n et w or k elem ent s. Th e net w or k schem a ex t ension s for t he dir ect or y ser vice ar e used t o t alk abou t n et w or k elem ent s and ser v ices. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r e 5 3 -6 . Sam pl in g of I m por t an t B ase Cl asse s of t h e DEN Sche m a Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . [ View full size im age]

New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The in t eg r at ion of t h e net w or k infr ast r uct ur e w it h t he d irect or y ser v ice allow s t h e applicat ions and user s t o d iscov er t he ex ist ence of dev ices an d r elat ionships b y quer y in g t he dir ect ory ser vice r at her t h an cont act in g t h e indiv idual devices and agg regat in g t he r esu lt s. Exp osin g n et wor k elem ent s in t he direct or y enhan ces m anag eab ilit y an d usabilit y w hile redu cin g t he load on t he net w or k. The end - user and adm inist rat or ex per ien ce is en hanced b ecau se t here is a single,

aut h or it at iv e p lace t o obt ain t he in for m at ion of in t er est .

The Extended Schema and Other Device Schemata Schemat a def in ed b y SNMP ( MI Bs) , D MTF CI M, an d so on, ar e int en ded p rim ar ily t o ad dr ess t h e det ails of indiv idual devices. The int ent of t he in t egr at ed , ext en ded schem a is t o lev erag e t he •inf orm at ion exp Table of Content osed by ex sist in g schem at a and m anag em ent fr am ewor k s, not t o r eplace t hem . •Fur t her mor e,I ndex t h e CI M an d DEN in for m at ion mod els ar e r eposit ory - ind ep en dent . Th is m ean s t hat It he nt e rn et w or k ing Te chnologie a ndbook th and Edit ion devices t hat ar e t o b es Hr ep resen,tFour ed in m anaged by a DEN sch em a do n ot t h em selv es hav e t oSystems, imp lem ent By Cisco Inc. LDAP. Pub lish er: Cisco Press

Network Pub Dat e: Sep Applications tem ber 1 1, 2 003 Integrated with the Directory and Other Network I SBN: 158 705 -1 19 -2 Protocols Pages: 11 28

The schem a an d inf or m at ion m odel d ef ined augm ent s ex ist ing n et w or k serv ices an d associat ed pr ot ocols, su ch as Dom ain Nam e Sy st em ( DNS) , Dy nam ic Host Config ur at ion Pr ot ocol ( D HCP) , and RAD I US. The d pr ov id es com mon st or e allfor innet w ork at ion; t he infporrov mat ion cover m odel d escr u irect pdat or edy edit ion of at he b est - selling one netinwfor orkming r ef erence ides age of ib es tessent he relat hat edg can ebe repr esen t ed in t he d irect or y. The usage mod el defines how exist ing ialionships an d cu t ttingt ech nologies. net w or k ser v ices an d p rot ocols w or k w it h t he element s in t h e inf orm at ion m odel t o accom plish specif ic goals, such as coor d in at ing I P add ress allocat ion acr oss mu lt ip le DHCP ser v er s, Conin cise ov erprv opagat iew s ofint echn olog essenlogin t ial t opolicy, n et wor ofession als at all lev els, f rom est ablish g and g r em ot eies access ank ding sopron. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Benefits of Using DEN

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age DEN had t h ree m ain use cases. The f irst w as t o h elp simp lif y dev ice con figur at ion . Device h ored by rCisco stecom ems, ewincr or ldw ide leader net w or f or t he Iof n t ter . por t ant conf igAut ur at ion has ecent Sy ly b easing ly com in plex , m ainking ly because wnoetim fact or s. First , d iff er ent t yp es of user s an d ap plicat ion s ar e v ying f or limit ed net w or k resour ces at It he n t ern et w k in Tech bookof , Four h Ed a her comtpr ehensive ence t hat sam e or t im e.gThe p nologies r oblem isHand not lack ban tdw idt ith ion , bu, tisr at r aff ic m ix ( trefer hat is, h ow t h ese enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing dif fer en t app licat ions, all w it h t h eir ow n specif ic needs, peacef ully coex ist in t he sam e net w or k). tThis echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing h as caused net w or k dev ice v endor s t o add m or e fu nct ionalit y in t heir devices. Thus, indu Lear n how o incort opor e or inte,errnet w or kining increasingly t echn olog iescom in t oplex a LAN/ envigur ir onm ent . net wst orry k . dev ices ar e tasked d oatm esult ing devWAN ice conf at ions. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and second speed, tuse h is book is a com pletr ol e an du t o- d at eent r efand er ence t o t he t op of icsnet t hat are essen The case was t o cont t he mpanagem pr ovisioning w or k dev icest ial t o all w or g purof pertmise. tnet hr ou ghkin t he se essionals, of p olicies.r egar The dless bu sinof essexcom unit y w an t ed a way t o m ap ser v ice- level agr eem ent s and business r ules t o a com m on set of policies. These policies w ou ld cont r ol t he Reader s wof ill net obtw ain reat er unbder st an of su LAN and WAN n et w oror k ing, p arap t icu t heefact or s. allocat ion or ka rgesou rces ased onding user, bnet , t im e- ofd ay, ot her prlar oprlyiat har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov Most im por t an t ly, t hey ensur e t hat ser v ices ar e im plement ed in a har dw ar e- independ en tided w ay on . Of a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions cour se, t his cannot be d one w it hou t a st andar d infor m at ion m odel. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov ext n ot aonly t o new n et wor ing concep but also t o- aw oldar ere, legacy The erag t hir de uissealso case isend t o ed define m eans t o mak e apk plicat ion s mt s, ore net w ork and t o mak e syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm s in w hich t he net w ork mor e ap plicat ion - aw are. Th is is accom plished in t he DEN in for m at ion ent mod el by pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease ensur ing t hat net w or k elem en t s, ser v ices, and ot her com pon en t s of a m anag ed env ir onm en t ar e pr ctesent iv it y an im pr ov e effs. iciency, help r eader m ake in capabilit t elligent ,ies, costt hen - eff icient allodu r epr ed dusing object I f all obj ecting s art he e equ al and hav emor eque al t h ey can decisions for t h eir net w ork s. all be repr esen t ed equally w ell, and comm u nicat ion b et w een t hem is assu red. Dir ect or y - En abled Net w or ks ser vices benefit diff er ent con st it uencies in dif fer en t w ay s. For t he en d u ser , it help s enable single sign - on ser vices. Sin gle sign- on ser v ices enab le t he sam e set of access r ight s and pr ivileges t o b e pr ov ided n o m at t er w her e, w hen, or h ow t h e user log s

on t o t he net w or k ( w it hin t he lim it s set by t he policies of t he sy st em , of cour se) . I n ad dit ion, it enables ind iv idu als t o be id en t ified and pr ovid ed ser v ices p rop or t ion at e t o t heir r ole in t h e com pany , serv ice con t r act , and so on. I t also helps com pan ies enf or ce soph ist icat ed policies. For exam ple, a business r ule m ay pr ohibit shippin g code over t h e pub lic I n t ern et . Thus, ev en t h ough a u ser successf ully aut hent icat es ov er a d ialu p line, t h e policy w ill cor r ect ly d en y aut h orizat ion t o connect t o a code ser ver b ecause t h e syst em r ecog nizes t hat t he u ser is conn ect ing ov er t he pu blic I nt ern et . The k ey t ech nology u sed her e is DEN' s r obust not ions of ser vices and policies, and t h e cap abilit y t o link t hem t o user s as well as d ev ices. • Table of Content s •

I ndex

Serv ice pr ov id er s ar e int er est ed in dir ect or y - en abled n et w or k ing becau se t hey need a w ay t o I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion pr ov ide dif fer en t iat ed serv ices. Th e $19 . 95 " all y ou can eat " p hilosop hy doesn' t ev en cover t he By Cisco Systems, cost of bu ild in g Inc. out new net w or king inf r ast ru ct u r e. I n add it ion , t h ey ar e int er est ed in using dir ect or y - enabled net w ork ing t o facilit at e t ur ning on new ser vices t hr ough cent r al m anag em ent . ThePub k ey ant ag e used h er e is t he capabilit y t o define policy - based man agement of net w or k lishadv er: Cisco Press elem ent s an d ser vices, Pub Dat e: Sep tem ber 1 1, 2and 003 t o isolat e t he ef fect of t u rn in g on n ew ser v ices t o a por t ion of t he net w orIk. SBN: 1- 58 705 -1 19 -2 11 28 En t er pPages: rise cust om er s n eed a cent r alized w ay t o pr ot ect m ission- cr it ical t raf fic an d t o bet t er m anage in cr easin gly com plex device conf ig ur at ions. DEN's capab ilit y t o associat e m ult ip le t raf fic st r eam s w it h a sing le applicat ion, along w it h it s capabilit y t o define policy - based man agement of net w or k elem ent s an d ser vices, is cr it ical her e.

App ioneddeveloper ov-id ed a stallandar d mnet eanwsork of ing reprresen t ing infor at ion descr The licat u pdat edit ion ofs ar t hee bprest selling in- one ef erence p rovm ides cover ageibing of net w orial k elem an dedg serevices. Th is en ables t hem t o bet t er lever age t h e pow er of t he n et wor k . essent an d ent cu t st ingt ech nologies. DEN' s capab ilit y t o descr ibe ap plicat ion s, t r aff ic t hat t hey gener at e, and how t o m anag e t hese set s of t r aff ic t hr ough p olicy is essent ial t o im plement in g t his goal. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

How DEN Is Used in Cisco Products Figur e 53 - 7 sh ows t he t w o layer s of m apping t h at ar e inh er ent in D EN. The fir st is fr om t he inf orm at ion m odel t o a t ar get reposit or y . This m app in g defines t h e t yp e of r ep osit or y t o be u sed, w hich in t u rn d ef ines t he w ay d at a is st or ed, t h e set of dat a st ru ct u r es t hat can be u sed, t he •pr ot ocol( s) t hTable s t o st or e an d ret r iev e t h e dat a, and ot her fact or s. The second at wof ill Content be used •m appin g is som I ndex et imes r equir ed eit her t o opt im ize t he im p lem ent at ion t o suit some applicat ionIspecif nt e rn et or k ing s Hdif a ndbook ion not imp lem ent t he sam e feat u res in t he sam e icwneed s,Te orchnologie because fer en t, Four v en th dorEdit s do t y pe of Systems, r eposit ory . By Cisco Inc. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Figu r e 5 3 -7 . D EN M a ppi ng s

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Cisco is philosophy t oatsteandar d izew or it skin use DEN. f act is WAN bu ild in g tirhronm ee ent . indu stis ry using . Lear nt hhow t o incor por int er net g tof echn ologI nies in t, oCisco a LAN/ env m odels. The f ir st is a st and ard m app in g of t he DEN inf orm at ion m odel int o a set of Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, im ent att hion A dir ory im plem .2ence an d ttoh et he policy m odel ill ship andplem speed, is s. book isect a com plet e anen d tuat p-ion t o- of d atCI eM r ef2er t op ics t hat w are essenear t iallyt oinall tnet he wsecond quar t er of 2 000 . or kin g p rof essionals, r egar dless of ex pert ise. The second a ain set of specif t ensions b eingn detev elop ed bpyarat icu cr ossReader s w illisobt a gcom reatm eron unCiscoder st an dingicofexLAN and WAN w or k ing, lar lyp rod t h euct gr oup ofe, Cisco eng in eer s. ser This m odel ex ted en.ds h e gener ic tcon s of inf CI or M mat an dion DEN t o ov a ided devicehar dw ar pr ot ocols, and v ices inv olv Futndam ent al echcept nology is pr on independ t e in of t erint m ediat lay . For exserv ampices, le, t he concept of ailed a por descr t is enipt hanced an diew lin quest ked t oions a b r oad r en ang egr alesy ster em s and in clud ing det ion s, rev n et wor k element s and v ices. tCiscoo en suspreecific con cept comp r eh en sion andser r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy The t hirs,d pr is ovid a setin of specif ic ur ext t hatwmod Cisco v sices. syst em g aapplicat m or e rionealist ic pict e ensions of t he realor ld el n et w or kdevices ing en virand onmser ent in wThis hich set of m odels is der iv ed fr om DEN and t h e Cisco ext ensions t o DEN. I t enables specif ic pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr Cisco ease dev ices and o be exiciency, plicit ly mod eledt he t o ar eader v er y fm in ake e levmor el ofe det ail in t he in for m icient at ion pr odu ct iv it y serv an d ices im prtov e eff help ing in t elligent , cost - eff m odel. decisions for t h eir net w ork s. I t shou ld b e not ed t hat by b asing t h e Cisco- sp ecific ex t en sion s on DEN, Cisco p r opr iet ar y net w or k elem ent s an d ser vices are mod eled based on a st an dar d. Th is is m uch b et t er and mor e pow er ful t han if Cisco had decided t o base it s w or k on eit her a com pet ing st andar d or ( w or se) no st andar d at all. I t gu aran t ees a lev el of int er operab ilit y wit h t h e st andar d, and it op en s t he w ay in t he f ut ur e t o exchan ge m or e det ailed inf or mat ion w it h it s par t ner s. The sam e is t r ue f or t h e

app licat ion- specific ex t en sion s t hat ar e based on t he Cisco ex t ensions.

The Directory-Enabled Networking Vision The v ision f or enhan cin g n et wor k ing t hr oug h in t eg rat ion w it h t he d irect or y ser v ice is t o pr ov ide net w or k- en abled app licat ions appr opr iat e inf or mat ion f rom t he d irect or y. Ev en t ually, in t elligent •net w or k app licat Tableions of Content w ill t rsan sp arent ly lev er age t he net w or k on behalf of t he user . Th e •dev elop ment I ndex of int ellig en t n et w or k s can b e achiev ed t hr ough t h e follow ing st ep s: I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Relyin g on a rob ust d irect or y ser v ice

Pub lish er: Cisco Press

Add in g a st and ard s- b ased sch em a for m odeling net w or k elem ent s an d serv ices

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 58 705 -1 19 -2for accessing, man aging, and m anipulat in g d irect or y infor m at ion Add in g1- pr ot ocols Pages: 11 28

The g oals of w ork in d ev elop ing dir ect or y - en abled n et w or k s ar e list ed her e: To p r ovide su ppor t for ap plicat ion s t hat hav e t he cap abilit y t o lev er age t he net w or k The uinf pdat edr uct edit of tsp hearent b est ly - selling ork ing r ef erence p rov ides cover age of rast urion e t ran on b ehallalfinofone t he net endw user essent ial an d cu t t ing- edg e t ech nologies. To p r ovide a r obust , ex t ensible fou ndat ion f or buildin g n et wor k - cen t r ic applicat ions Con cise le oven er vd-iew of t nechn ies essen t iala t pero n etuser wor kbing To enab t o-send et w olog or k serv ices on asispr ofession als at all lev els, f rom nov ice t o ex pert . To enab le net w or k- w ide ser vice cr eat ion and pr ov ision in g New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP To enab le net w or k- w ide man agement Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age The f ocus is on pr ov iding m anagem ent of t he net w or k as a sy st em, not a set of dispar at e Aut h ored Cisco Sydevice st ems,int w er or faces. ldw ide Using leaderdir inect net king f ort ot he et .r elat ionship com ponent s or by indiv idual orwy or serv ices defI ninteertnhe am ong comp onent s allow s t h e net w or k man ager t o man age t h e net w or k as a sy st em . Vend ors I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat hav e adop t ed de f act o op en ind ust r y st andar ds, such as DNS and DHCP, t o t ie t h ese serv ices enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing int o t heir ent er pr ise m anag em ent syst em s. DEN is t he nex t such st andar d . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary This chap t er has p rov ided a br ief int r oduct ion t o D irect or y- Enabled Net w or k s. DEN is t w o v ery im por t ant t hing s. Fir st an d f or em ost , it is an object - or ien t ed inf or mat ion m odel t h at is u sed t o descr ibe en t it ies t o be m an aged in an en vir onm ent . Alt h ough t h er e ar e m any su ch m odels, DEN •is un ique in tTable s hat itofisContent t he only m od el t o describe, in a reposit or y- in dependent fashion , bot h •net w or kin g element I ndex s and ser v ices as w ell as ot h er object s t h at t og et h er con st it u t e a man aged Ienv nt e rn et wment or k ing Te chnologie s H adef ndbook th Edit g ion iron . Second , DEN in es, aFour m appin f or t h e dat a sp ecified in t he DEN inf orm at ion m odel o a f ormInc. t hat can b e st ored and r et rieved in a dir ect ory ( wh ich uses eit her LDAP or X. 50 0 By Cisco tSystems, as it s access p rot ocol) . Pub lish er: Cisco Press

A b r ief int r odu ct ion t o obj ect - or ien t ed in for m at ion m odeling, and t he b en ef it s of using such an Dat e: Sep tem ber 1 1, 2 003 appPub roach, w as descr ibed. Th is m et h od en ables any ent it y t h at n eeds t o be man aged t o be I SBN: 705 -1 19 -2t m ann er in t h e m anaged en vir onm ent . Direct or ies ar e on e imp or t ant m odeled in 1a 58 consist en Pages: exam ple of 11 m 28 ap ping t his inf or m at ion . This is b ecau se d irect or ies alr eady cont ain im por t ant inf orm at ion, su ch as user s, pr int er s, and ot her n et w or k r esou rces. Concept u ally , DEN ex t en ds t he t yp e of dat a t hat can b e m odeled in direct or ies, an d show s how t h at inf or mat ion is r elat ed t o dif fer en t t y pes of dat a in ot her t y pes of dat a st or es. DEN m seda edit cor ner one uilding intallelliginenone t n etnet w or k serv as w ell as ides cont rcover ollingage systofem s The ufor pdat ionstof t heofb best - selling w ork ingices, r ef erence p rov tessent hr ou gh policies. DEN m odels t he n et w or k as a pr ov id er of int elligent ser v ices, and m odels ial an d cu t t ing- edg e t ech nologies. client s of t he n et w or k as u ser s of t hose ser vices. Th is pr ov id es a m et hodology t o m ak e app licat ions mor e aw ar e of t he net w ork and t o m ak e t he n et wor k m or e aw ar e of t he n eeds of v ariouCon s applicat cise ov ions. er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Finally, ex am ples of how D EN is u sed w it hin Cisco Syst em s t o b uild a new set of in t elligent pr oduNew ct s and solu w er ecov prerag ovid ed . im por t ant t opics like VoI P and EAP chapt er tsions include e of Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What is DEN?

2:

I ndex DEN r equir e t he use of a dir ect ory ? Does

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : I s DEN By Cisco Systems, Inc. 4:

ju st abou t m odeling net w or k devices and ser v ices?

What is an obj ect - or ient ed in for m at ion m od el?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

Nam e some of t he im por t ant benefit s of D EN.

I SBN: 1- 58 705 -1 19 -2 Pages: 28 6 : 11How

d oes D EN m od el relat ionships bet w een object s?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information D EN a nd Re la t ed St and ar ds W ork The D esk t op Manag em ent Task For ce ( DMTF) is t he ind ust r y consort iu m char t er ed w it h • of Content dev elop mentTable , su ppor t , ands main t en ance of m anagem ent st an dar ds f or PC sy st ems and pr oduct s, •includin g CI M I ndex and DEN. Mor e inf orm at ion can be obt ain ed f rom ht t p: / / w w w . dm t f. or g. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

W ork i ng Gr ou ps i n t he I ETF By Cisco Systems, Inc. The ch art er of t h e Policy Fr am ew or k Wor k ing Gr oup of t he I ETF is available f r om Pub er:wCisco Press ht t p: / /lish ww . iet f .or g / ht m l. ch art er s/ policy - char t er .h t m l. Pub Dat e: Sep tem ber 1 1, 2 003

The LDAPEXT ( LDAP I SBN: 1- 58 705 -1 19Ex -2 t ensions) Wor k ing Gr oup of t he I ETF is ch art er ed wit h cont inu ing t o dev elop an I nt ern et dir ect or y ser vice. The LDAPEXT Work ing Gr oup d ef ines and st andar dizes Pages: 11 28 ext ensions t o t h e LDAP Ver sion 3 p rot ocol, ex t ension s t o t he use of LDAP on t h e I nt ern et , and t he API t o LDAP. Mor e in for m at ion can be ob t ained f r om ht t p: / / w w w . iet f .or g / ht m l. ch art er s/ ldapex t - ch ar t er . ht m l. The LDUP ( LDAP D uplicat ion an d Upd at e Pr ot ocol) Wor k in g Grou p of t he I ETF is char t er ed w it h The ed edit he b and est - selling allork r ef erence p rovdides cover age or ofy definuinpdat g addit ionsion ( profottocol sch em at a)int oone t he net LD w AP pring ot ocol t o enable if fer ent d irect essent ial an d cu t t ingedg e t ech nologies. v en dor s t o replicat e w it h each ot her . Mor e inf or mat ion can be obt ain ed f rom ht t p: / / w w w . iet f .or g / ht m l. ch art er s/ ldup- ch art er . ht m l. Con(cise ov Adm er v iew s of Policy t echn olog ies ing essen t ial tof o nt hetewor k ing pr ofession at developing all lev els, f rom The RAP RSVP ission ) Work Gr oup I ETF is concern ed als w it h nov ice t o ex pert . st andar d s for enab lin g a scalab le policy con t rol m odel t hat can p r ovide qualit y of serv ice on t he I nt er net u sing ex plicit sig naling pr ot ocols su ch as RSVP. Com m on Open Policy Ser vice ( COPS) New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP defin es a pr ot ocol t o t r ansm it policy r eq uest s and r espon ses. Mor e inf or mat ion on bot h can be fou ndCov at erag ht t p:e/ /of w wcut w .tiet g / httm l. chologies art er s/ rap t er .nht l. k ing and st or age ingf .or edge echn lik e- char opt ical etmwor Sim ple w orkbyManagem t Pr otw ocol ( SNMP) is t heinde m anagem dar AutNet h ored Cisco Syen st ems, or ldw ide leader netf act w oro king f or t heent I n tst eran n et . d f or I Pbased sy st em s. Sev er al I ETF wor k ing gr oup s act iv ely w ork on t he dev elop ment of SNMP. Tw o t o exam t hese: I n t ernine et war orek in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing ht t p: / / w w w . iet f .or g / ht m l. ch art er s/ agent x - char t er . ht m l indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet ew d gu/pdat edchchapt ersn s on secur it y ,t er. st or ht t p: / /itwhwnew w . ietan f .or ht m l. art er s/ m pv 3- char htage, ml opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net wgor kinof gp essionals, dless The oal t hrof e fir st w or kinr gegar g rou p is of t o ex m pert ak e ise. t he SNMP Agent m ore ex t ensible. The g oal of t he SNMPv 3 Work ing Gr oup is t o define t he n ex t generat ion of SNMP. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har ar e, ot ocols, v icesMan invagem olv ed en . Fu al t ech nology inf or le mat pr ov ided on Thedw Rem ot eprNet w or k and Mon ser it oring t Indam nf orment at ion Base is av ailab inion t w oisver sion s. The a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions follow ing RFCs d ef ine it : t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em hts, t p:pr / /ovid inf o.iningt ern a metor. isi.edu e r ealist / inic not pictes/ ur er fc/ offiles/ t he realrf c175 w or 7. ld t xtn et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease " Rem e dNet k eMonit or ing Manag emt he entr eader I nfor mm atake ion mor Base" pr odu(ct iv it yotan imwprorov eff iciency, help ing e )in t elligent , cost - eff icient decisions for t h eir net w ork s. ht t p: / / inf o. in t ern et . isi.edu / in- not es/ r fc/ files/ rf c202 1. t xt ( " Rem ot e Net w or k Monit or ing Manag em ent I nfor m at ion Base v2 Usin g SMI v2 " ) ht t p: / / inf o. in t ern et . isi.edu / in- not es/ r fc/ files/ rf c207 4. t xt

( " Rem ot e Net w or k Monit or ing MI B Pr ot ocol I dent if ier s" ) RSVP is defined by sever al RFCs. Th e ones m ost r elev ant t o t h is book ar e list ed h er e. Also check t he RAP Wor k ing Gr oup. Go t o t h e URL ht t p: / / inf o. in t ern et . isi.edu / in- not es/ r fc/ files/ . Th en pu ll t he follow in g files: r fc22 05. t x t — " RSVP Fun ct ion al Specificat ion" • •

Table of Content s

r fc22 06.I ndex t x t — " RSVP Managem en t I nf or mat ion Base Using SMI v 2"

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

r fc22 07. t x t — " RSVP Ext ensions for I PSec Dat a Flow s"

By Cisco Systems, Inc.

r fc22 08. t x t — " RSVP Ap plicab ilit y St at em ent " Pub lish er: Cisco Press Pub r fc22 Dat e:09. Sept tem xt— ber" RSVP 1 1, 2 003 Message

Pr ocessing Rules"

I SBN: 1- 58 705 -1 19 -2

rPages: fc22 10. t x t — " The Use of RSVP w it h I ETF I nt egr at ed Ser v ices" 11 28 The D iff er ent iat ed Ser v ices I ETF Wor k ing Gr oup is defin in g " relat iv ely sim ple and coar se m et hods of p rov iding d if fer ent iat ed classes of serv ice for I n t er net t r aff ic. " Sp ecif ically, a sm all set of bu ild in g block s is d ef ined t hat en ables qualit y of serv ice t o b e defined on a per - hop basis. This w or k is d escrib ed in ht t p: / / w w w . iet f .or g / ht m l. ch art er s/ diff ser v - ch ar t er . ht m l. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent The I n ial t egan ratdedcuServ t t ingices edgWork e t ech ing nologies. Gr oup of t h e I ETF Recen t Exp er im en t s dem onst r at es t he capabilit y of pack et - sw it ching p rot ocols t o supp ort int egr at ed ser vices—t he t r anspor t of audio, v ideo, r eal- t im e, and classical dat a t r aff ic w it hin a single net w or k inf rast r uct u re. Mor e cisecan ov er ofed t echn olog ingerpr els, f rom inf ormCon at ion b ev iew obtsain at ht t p: ies / / w essen w w . iett ial f .ortgo / nhtetmwor l. chkart s/ofession int ser v - als charatt erall . htlev m l. nov ice t o ex pert . Re fe re nce s on D i re ct orie s New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Pr obably t he best sour ce of inf orm at ion on dir ect or ies is in t h e t w o I ETF w ork ing gr oup s Cov erag of cutw t ing ologies e opt ical n et k ing and st or age LD APEXT an d eLDUP, hichedge w er et echn descr ibed prlik eviously . Tw o wor ad dit ional p ublic URLs t hat con t ain som e gr eat inf orm at ion on dir ect or ies are t hese: Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ernhtett w nologies Hand book Four p:or / /kwinwgwTech . cr it icalan gle.com / ldap, wor ld/t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t sm he ou t ernt main. s, con cepldt s, t echn map ologies, anl d devices used in t oday ' s net w ork ing ht t p: / / w w w . king com/ apRoad . sh t m indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com St r assn pletere ,wJoh it h n. new Dir ect an dory u pdat Enab edled chapt Net er w or s on k s. secur I nd ianapolis: it y , st or age, Macm optillan ical Technical net w or k inPub g, scalabilit lishin g, y, and99. 19 speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 54. Network Caching Technologies • Obj e ct i ve s Table of Content s •

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Descr ibe cur r ent net w ork t raf fic ov er load issu es.

By Cisco Systems, Inc.

Descr ibe h ow caching solv es m any of t h ose issues. Pub lish er: Cisco Press

Descr h ow Pub Dat e: ibe Sep tem bernet 1 1,w 2 or 003k

cach ing w ork s.

I SBN: 1- 58 705 -1 19 -2

Descr ibe d iff er ent cachin g t echnolog ies in use t od ay. Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction Alt hou gh t he v olum e of Web t r affic on t h e I nt er net is st agg er ing , a lar ge p er cent age of t hat t r aff ic is r ed und ant –m u lt ip le user s at any g iven sit e requ est mu ch of t h e same con t en t . This m ean s t hat a sign ificant percent age of t he WAN in fr ast r uct ur e car ries t he id en t ical con t ent ( and •ident ical r equest Tables of s aft er d ay. Elim inat in g a signif icant am ount of r ecur r ing forContent it ) d ay •t elecom m unicat I ndex ions char ges of fer s an en orm ou s saving s opp ort u nit y f or ent erp r ise an d ser vice Ipr ntov e rnider et w or k ingom Teer chnologie s H a ndbook , Four th Edit ion cust s. By Cisco Systems, Inc.

Web cachin g p er f orm s t h e local st orag e of Web cont en t t o ser v e t hese r ed und ant u ser r equest s m or e quick ly , w it h out send in g t he r equest s and t he result ing cont ent over t h e WAN. Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Network Caching Net w ork caching is t he t echniqu e of k eeping f requ en t ly accessed inf orm at ion in a locat ion close t o t he r equest er . A Web cache st or es Web pages and cont ent on a st or age d ev ice t hat is ph ysically or logically closer t o t he user –closer and fast er t han a Web look up. By r ed ucing t he •am ount of t r aff Table of Content s s and on ov er bu rd en ed Web ser v er s, caching pr ov id es sig nificant ic on WAN link •benefit s t o I SPs, I ndexent er pr ise n et w or k s, and end user s. Ther e ar e t w o k ey benefit s: I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Cost sa v in gs du e t o W AN ba ndw i dt h re duct i on – I SPs can p lace cache eng in es at st r at eg ic point s on t h eir net w ork s t o imp r ove r esponse t im es and low er t he ban dw idt h Pub lish er: Cisco Press dem and on t heir back bones. I SPs can st at ion cach e engines at st rat eg ic WAN access poin t s Pub e: ve SepWeb tem berr equest 1 1, 2 003s fr om a local disk r at her t han f r om dist ant or ov er r un Web ser ver s. t oDat ser I SBN: 1- 58 705 -1 19 -2

IPages: n en t er 11 pr 28 ise net w or ks, t h e dr am at ic r ed uct ion in b andw idt h usage due t o Web cachin g allow s a low er- b andw idt h ( low er - cost ) WAN link t o ser v e t h e sam e u ser b ase. Alt er nat iv ely , t he org anizat ion can add u ser s or ad d m or e ser v ices t h at u se t he f reed band wid t h on t h e exist ing WAN link . I m prov e d p rodu ct i v it y f or end use rs— The r esp onse of a local Web cache is oft en t hr ee The utpdat edit of tthhe b estnload - selling in- one net weork ingent r efover erence rov ides age of im esedfast erion t han e dow t imalle for t he sam cont t h ep WAN. Encover d u ser s see essentdrial an d cu t t ingedg e t ech nologies. am at ic im pr ovem ent s in r espon se t imes, and t h e imp lem ent at ion is comp let ely t r anspar ent t o t h em . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Ot h er benefit s includ e: nov ice t o ex pert . New chapt er sss include covaerag e onit of imor por ant The t opics like engine VoI P and EAPes n et wor k Se cure a cce cont rol nd m in tg— cache pr ovid adm inist r at or s w it h a sim p le, secur e m et h od t o enf orce a sit e- w ide access p olicy t h rou gh Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age URL filt erin g. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Ope r at i ona l logg ing — Net w or k adm inist r at or s can lear n wh ich URLs receiv e hit s, h ow s per seconHand d t hebook cache is serv ing, w hat of URLs ar eence ser v ted I n t ernmetany w orrkequest in g Tech nologies , Four t h Ed it ion , is percent a com prage ehensive refer hatf rom t he cache, an d ot her r elat ed operat ion al st at ist ics. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it hCaching new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, How Web Works and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g gp rof r egar Web cachin w oressionals, k s as f ollow s: dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a 1b .r oad angaccesses e of int egr sy stpag eme. s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions A urser a al Web t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . 2 . erag Thee nisetalso wor kext anend alyzes h eonly r eq uest , andn et based on cer t ain tpar am et er s,t ot r old anspar ent ly Cov ed ntot t o new wor k ing concep s, but also er , legacy r ed s it int og aa local wor kic cache. syst em s,irect pr ovid m or enret ealist pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease . Ict f tivhe d oes h ave t he Web page, w ill mak e it smor ow e n in Web requ est t o -teff heicient or iginal pr3odu it ycache an d im pr ovneoteff iciency, help ing t heitr eader m ake t elligent , cost Web for sertver decisions h eir. net w ork s. 4 . The or igin al Web ser ver d eliv er s t h e cont ent t o t h e cach e, wh ich deliver s t h e con t ent t o t he client w hile savin g t he cont ent in it s local st or age. Th at cont ent is now cached. 5 . Lat er , an ot her user r eq uest s t he sam e Web page, and t h e net w or k analy zes t his r eq uest , and based on cer t ain p aram et ers, t ran sp arent ly redir ect s it t o t he local n et w or k cache.

I nst ead of sendin g t h e r eq uest ov er t he I nt er net an d I n t r anet , t he net w ork cache locally fu lf ills t he requ est . Th is pr ocess acceler at es t he d eliv er y of cont ent . The im por t an t t ask of ensur ing t hat dat a is up - t o- dat e is addr essed in a var iet y of w ays, depend in g on t he design of t he sy st em .

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Table of Content s

The Benefits of Localizing Traffic Patterns • I ndex I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

I m plem ent ing caching t echnology localizes t r affic pat t er ns and add r esses net w ork t raf fic By Cisco Systems, Inc. ov er load pr oblems in t h e follow ing w ays: Pub lish er: Cisco Press

Con t is d ber eliv1er to Pub Datte:enSep tem 1, ed 2 003

u ser s at acceler at ed rat es.

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WAN b andw idt h u sag e is opt im ized. Pages: 11 28

Adm inist r at or s can m or e easily m onit or t raf fic.

Network-Integrated Caches The u pdat ed edit ion of t he b est - selling

all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The f ir st st ep in creat ing a net w ork - int egr at ed cache en gine is t o ensur e t hat t he net w ork supp ort s t r aff ic localizat ion, w h ich can be achieved by enab lin g cont en t r out ing t echnolog y at t h e syst em Con - lev cise el, ov and er vset iewt in s gofsp t echn ecificolog p aram ies essen et ers ttial o op t ot imize n et wornketing w orprk ofession t r af fic. Cisco als at Iall OSlev ® els, Webf rom Cachenov Com icemu t o nicat ex pert ion. Pr ot ocol ( WCCP) is one exam p le of con t en t r out in g t echn olog y t hat can b e set t o su ppor t t r affic localizat ion. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP On ce t he r ight net w or k fou ndat ion is in place, net w ork caches ar e add ed int o st rat eg ic point s e in ofgcut t ing t echn ologies lik e opt ical n et wor k ing and st or age w it hinCov t heerag ex ist n et woredge k. Aut h ored st ems, or ldw ide leader in net f oredt he I n t erengine. n et . By pair ing soft wby ar Cisco e and Sy h ard w are,w Cisco cr eat es a net w orwk-orinking t eg rat cache I n t ern et w or kegr in gatTech nologies Hand t h Edin it g iont hr , is com pr ehensive refer ence t hat Net w ork - int ed cach es h ave at book least, tFour he follow eea pr opert ies: enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing e net or king mer ennet t , rwesult ingg tin m inim ionalWAN costenv s ir onm ent . indu stMan ry . aged Lear nlik how t owincor porequ at e ipint or kin echn ologized ies inoper t o aatLAN/ Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Desig ned e higish-adensit y net w or har dwe ar e,erresult er phy egr at ion and speed, t h is lik book com plet e an d kuin p-gt od at r ef ence ing t o t in he bet t opt ics t hatsical are int essen t ial t o all int o t he n et w or k inf r ast ru ct u r e as net w or k ex t ensions an d m inim izing cost s associat ed w it h net w or kin g p rof essionals, r egar dless of ex pert ise. leasing r ack space Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e ly insert o t he et wedor. kFu , rndam esult in g al in tm inim iz ed deploy m en d ov op ided er at ional har dwTraranspar e, pr otent ocols, and ed serint v ices invnolv ent ech nology inf or mat iont an is pr on costr ang s and gr int eategr er al consyt ent avs ailabilit y ices, in clud ing det ailed descr ipt ion s, rev iew quest ions a b r oad e of st em and serv t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr Existing Caching ovid in g aSolutions m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ctee iv itmost y an dcom im pr iciency, help ing r eader ake cost - eff iciente The t hr mov onet eff y pes of caches on tthhe em ark et m t od ay mor ar e eprin oxt elligent y ser v er, s, st andalon decisions for t h eir net w ork s. cach es, an d br ow ser - based caches.

Proxy Servers

Pr oxy ser ver s ar e sof t w are applicat ions t hat r un on gener al- p ur pose har dw ar e an d op er at ing syst em s. A pr ox y ser v er is placed on har dw ar e t h at is p hy sically bet w een a clien t ap plicat ion , such as a Web br ow ser , an d a Web ser ver . The p r oxy act s as a gat ek eep er t hat receiv es all pack et s dest in ed f or t he Web serv er and exam ines each p ack et t o det er min e if it can f ulf ill t he r eq uest s it self; if not , it m akes it s own r equest t o t he W eb ser v er. Prox y serv er s can also b e used t o filt er r eq uest s, f or exam p le, t o pr event it s em ploy ees f rom accessing a sp ecific set of Web sit es. •

Table of Content s

Unfor t u nat ely, pr oxy ser ver s ar e not opt im ized f or cach ing, an d do n ot scale und er heavy • I ndex net w or k loads. I n addit ion, becau se t he p rox y is in t he p at h of all user t r aff ic, t wo pr oblem s I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion ar ise: all t r aff ic is slow ed t o allow t h e pr ox y t o ex amin e each pack et , and failur e of t h e pr ox y By Cisco soft w ar Systems, e or h ardInc. w are cau ses all u ser s t o lose n et w or k access. Ex pensiv e har dw ar e is r equir ed t o com pensat e for t he low sof t w are p er f orm an ce an d t he lack of scalabilit y of p rox y serv ers. Pub lish er: Cisco Press

Pr oxies also r equir e conf ig ur at ion of each user ' s br ow ser —a cost ly an d u nscalab le man agement Pub Dat e: Sep tem ber 1 1, 2 003 t ask for ser v ice p rov ider s and lar ge ent er pr ises. I n ad dit ion, pr oxy ser ver s t hat ar e ar ran ged in a I SBN: 1- 58 705 -1 19 -2 hier archical f ash ion f or m an addit ion al ov er lay net w or k, con t r adict in g any plan s t o st r at egically 11 28 conv erPages: ge dispar at e net w or ks in t o a sin gle, unif ied net w or k.

Standalone Caches The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Iessent n response shor t com ingsnologies. of pr oxy ser ver s, som e v endor s h ave cr eat ed st andalone ial an dt ocut he t t ingedg e t ech cach es. Th ese caching- f ocused soft war e ap plicat ion s and app lian ces ar e designed t o im pr ov e per for m ance by enh ancing t he caching soft w ar e an d elim in at ing ot her slow aspect s of pr ox y ser v erCon imp lemov ent ions. Wthile a st ep int ial t het or igh dir kect t hese stals andalon cach ar e cise erat v iew s of echnt his ologisies essen n ettwor ingionpr, ofession at allelev els,esf rom not net w or egrpert at ed, nov icek tint o ex . r esu lt ing in h ig her cost s of ow nership and m ak ing t hem less d esir able for w id e- scale deploy m en t . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Browser-Based Client Caching

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I nt er net b row ser applicat ions allow an ind ividu al user t o cache W eb pag es ( t hat is, im ag es an d I n t ern et w or k in g Tech nologies t h can Ed itconf ion , igur is aecom ehensive refer space ence t hat HTML t ext ) on his or her local Hand har d book disk . , AFour user t h e pr am ount of disk devot ed or kin un derst imwplem en tf or cont em porearNavigat y int er net tenables o cachinnet g. w Figur e g54p-r1ofessionals sh ows t het o cache confand ig uran at d ion in dow Net scap or. w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, is book is aUse com plet an dche u p- t Conf o- d at eig r ef eraence t he t op ics tthat are essen Figu r e 5 4t h-1 . You t hee Ca ur t iont o W i ndow o Con f igutrial e ttohall e net w or kin g p rof essionals, r egar dless of ex pert ise. Am ou nt of D isk Space De vot e d t o Cachi ng in N et sca pe N av iga t or Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov iceist usefu o ex pert This set up l in. cases w here a user accesses a sit e m ore t han once. The f irst t ime t he u ser v iew s a Web sit e, t hat cont ent is saved as files in a subd irect or y on t hat com pu t er' s har d disk . chapt er su include e of im por likeget VoI and EAP The nNew ex t t im e t he ser p oincov t s terag o t his Web sit e,t ant t h et opics br ow ser sP t he con t en t f rom t he cache w it hout accessin g t he n et w or k . The u ser n ot ices t h at t h e elem ent s of t h e page- - especially lar ger Cov erag esuch of cut echn ologies e opt ical n et st orlyage Web gr aphics ast ing but edge t ons, ticons, and imlik ages app ear mwor u chk ing m orand e quick t han t hey d id t h e fir st t im e t h e pag e w as opened. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . This m et hod ser v es t his u ser w ell, but does n ot benef it ot her u ser s on t he sam e net w or k w ho I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat m ight access t he sam e Web sit es. I n Figur e 54 - 2, t h e fact t hat User A h as cach ed a popu lar page enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing has no eff ect on t he d ow nload t im e of t his pag e for User s B and C. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Figu r e 5 4 -2 . Th is Figu r e De m onst r a t e s t he B en ef it s Ga ine d by a Si ng le net w or kin g p rof essionals, r egar dless of ex pert ise.

Nod e Usi ng Br ow se r Cachin g

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant WCCP Network Caching

t opics like VoI P and EAP

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age IAut n 199 7, Cisco dev elop WCCP, a rou - cache rotwocol t hatf or localizes net w ork t raf fic an d h ored by Cisco Sy sted ems, w or ldw idet er leader in pnet or king t he I n t er n et . pr ov ides " net w or k- in t elligent " load dist ribu t ion acr oss m ult iple net w or k caches for I n t ernmetaxim w or kized in g Tech d ow nload nologies perfHand or man book ce ,and Fourcon t h tEd entit ion availabilit , is a com y . pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing The cache com t of t h con e Cisco cach in g ologies, solut ion an com pr ises net w orin k - int egr'at t echnologies. Mast erpon t heent er m s, cep t s, t echn d devices used t oday s ed netcaching w ork ing solut ions—t he Cisco Cache En gine 5 00 Ser ies. They ar e net w or kin t eg rat ed because indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onmt hey ent .: Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Pr ovid e w or k isman agem enet an capab ies alre ead y ence available ont op t r adit Cisco nettwial ortking and speed, t hnet is book a com plet d u p-ilit t od at r ef er t o t he ics ional t hat are essen o all gear ( such as Cisco I OS CLI an d RADI US supp ort ) , r esult ing in m in imized m anagem en t an d net w or kin g p rof essionals, r egar dless of ex pert ise. oper at ional cost s. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e t ly desig lemed ent edndam as cach specif ic netinf w or or mat kin gion h ard r at hon er har dwAr aree,inher pr oten ocols, and ned ser vand ices imp inv olv . Fu ent in alg-t ech nology is w prare, ov ided t han b eing and ser v er plat serv f ormices, s ad apt ed ing as caches. s, tipt he ion h ighd eniew sit yquest Ciscoions a b r oad r ang e ofstint egralone al sy st em s and in clud det ailedThu descr s, rev Cache Engin p hyrsically int egr et tter in and t o t had e net w or k rinfr ast r uctfur n et wstor k . t o en su re con cept es comp eh en sion andat reetben ion, dit ional esou r ces orefuas rt her udy ext e ensions ranend sp aredennt ot ly inser t o exnist g nk et w or k inf r tast r es tan t o u nusual Cov erag is also text only tt oinnew etin wor ing concep s, ru butct ualso o d oldadapt er , legacy net orovid k condit r esult ingicinpict m ur inim ized loym at ion and gr w eat er syst em s,wpr in g aions, m or e r ealist e of t hed ep realw orent ld nand et w oper or k ing en al vircost onmsent s in hich cont ent availabilit y. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Network-Based Shared Caching The cache eng ine w as designed fr om t h e gr oun d u p as a loosely cou pled , m ult inod e net w ork syst em op t im ized t o p rov ide r obu st shar ed n et w or k caching. The cache engin e solu t ion com pr ises t he Web Cach e Cont r ol Prot ocol ( a st andar d f eat u re of Cisco I OS soft w ar e) an d on e or

m or e Cisco cach e en gines t hat st or e t he d at a in t he local n et wor k . The W eb Cache Cont r ol Pr ot ocol d ef ines t he com m unicat ion bet w een t he cache eng ine and t h e r out er . Using t h e Web Cach e Cont rol Prot ocol, t he r out er dir ect s only Web requ est s t o t h e cache engine ( rat her t han t o t he int en ded ser ver ) . The r ou t er also det er m ines cach e engine av ailab ilit y , an d r edir ect s r equ est s t o new cache engin es as t hey ar e add ed t o an in st allat ion. The Cisco cache eng ine is a sing le- p ur pose net w or k app lian ce t hat st or es and r et riev es con t en t • Content s using high ly Table opt imofized caching and r et riev al algor it hm s. ( See Figur e 54 - 3. ) •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Figu r e 5 4 -3 . Th is Figu r e Sh ow s a Cisco Ca che En gin e Con ne ct ed t o a Cisco I O S Rout er Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Transparent Caching indu st ry . Lear nNetwork how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, h is tbook is aent com e anas d ufollow p- t o- sd at e r efeer54 ence A cache engtine r anspar ly plet caches ( Figur - 4) :t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e 1 .dwAarue, serprr ot equest a Web romolvaed br.ow . ent al t ech nology inf or mat ion is pr ov ided on har ocols,s and serpvage ices finv Fuser ndam a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions . su The CCPenab ledr eh r out analy het ion, r equest andit d bional asedr esou on TCP p or mher ber,st udy . t o2en re W con cept comp ener sion andzes r etten and, ad r ces f ort nu fu rt deteeris min es ext if itend sh ould t r anspar t ly rned ect kiting t o concep a cachet s,enbut gine. Cov erag also ed n ot only t oennew etirwor also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich I f a cache engin does not e elines t he requ edimcon t ent , it em set sper u pfora m sep ar atweillTCP nect ion pr3of. essionals oper at e.e Tools and hav gu id f orest opt izing syst ance incrcon ease t o t he end ser v er t o r et r iev e t he con t en t . Th e con t ent r et ur ns t o, and is st or ed on , t he pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient cach for e engine. decisions t h eir net w ork s. 4 . The cache eng ine sen ds t h e cont ent t o t h e client . Up on sub sequ en t r equest s f or t he sam e cont ent , t he cache engin e t r anspar en t ly fu lf ills t he r equest s f rom it s local st or ag e.

Figu r e 5 4 -4 . Tr a nspar e n t N et w or k Ca chi ng

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Becau The u pdat se t he ed WCCP edit ionr out of ter her b edir estect - selling s packet all-sind est oneined net w forork Wing eb rser ef erence v ers t o parov cache ides en cover gine, age t he of essent cach e engine ial an d operat cu t t ingesedg t r an e tsp ech arent nologies. ly t o client s. Clien t s do not need t o con figu re t heir br ow ser s t o point t o a specif ic pr ox y ser v er . Th is is a com pellin g f eat ur e for I SPs and larg e ent erp rises, for w hom u nifor m b r owser conf ig ur at ion is ex pensiv e and diff icult t o m anage. I n addit ion , t he cache Con cise ov v iew s of t echn iesnet essen ial the o nr et wor ing ofession alsinat itall els, engine operat ioneris t r anspar ent tolog o t he w or tk—t out er kop er pr at es ent ir ely s nlev orm al rf rom ole f or nov ice t o ex pert . non redir ect ed t r aff ic. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Hierarchical Cov erag eDeployment of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Cisco Eng Sy st or ldw ide net wand or king orwor t hek Iop n t er n . cu st omer s BecauAut se haored CiscobyCache inems, e is t rwanspar ent leader t o t h e in client t o nfet atet ion, can easily place cach e en gines in sev er al net w ork locat ions in a hier ar chical fashion . For I n t ernple, et w or in gI SP Tech nologies Hand book , Four , is point a comof pr ehensive t hat exam if kan deploy s a Cache En gine 5 90t hatEdititsion main access t o refer t he Ience nt er net , all of enables oresence kin g p r(ofessionals t o un dersteand an.dClient im plem t cont emt por ar y intCache er net wEng orkin ing it s poin t snet ofwpr POPs) benefit ( Figur 54 - 5) r eqenuest s hit he Cisco e t echnologies. Mast er frt he cepTo t s,fur t echn d devices usedt s,inI tSPs oday ' s net ork ting 59 0 an d are f ulf illed omt er it smsts,orcon age. t h er ologies, im p rov eanserv ice t o clien can d epwloy he indu st ry . Lear how incor at ePOP. int erTh net olog ies in t ot a onmest entis . Cache Engin e n590 or t 5o 70 at por each enw, or w kin heng at echn client accesses heLAN/ I nt erWAN net , env t he irrequ Com w ited h new d u pdat ed chapt s oncache secur is it yu, nable st or age, opt ical w orest k in fr g,om scalabilit fir st plet r edireect t o t han e POP cache. I f t h eerPOP t o fu lfill t h enet requ local y, and speed, is es book is m a al com pletr eeqan d u tpe rser ef erv ence t op are essen t ial o all st or age, it mt hak a nor Web uest o ttohed at end er. Upt ost tr he eam , tics his trhat equest is r edir ectt ed kin g pCach rof essionals, egar dless ex pert ise. tnet o tw heorCisco e Eng ine r59 0 at t he of main I nt er net access p oint . I f t he requ est is fulf illed by t h e Cisco Cache Engin e 590 , t r aff ic on t he m ain I nt ern et access link is av oided, t h e or igin Web Reader w per ill obt ain low a g er reat er un derand st antding of LAN andiences WAN n et w k ing, icu lar ly tthimes. e ser v erssex ience dem and, he clien t ex per bet t erornet w orpkarrtesp onse har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov En t er p rise net w or ks can app ly t his h ier ar ch ical- t r anspar ent ar ch it ect ur e t o benefit in t heided sam on e a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions w ay ( Figur e 54 - 6) . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Figu r e 5 4 -5 . H ie r ar ch ical I m ple m en t a t i on of Ca che En gin e s ( I SP) pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

Figu r e 5 4 -6 . H ie r ar ch ical I m ple m en t a t i on of Ca che En gin e s Ent e priti ion se ,) is a com pr ehensive refer ence t hat I n t ern et w or k in g Tech nologies Hand book ,( Four t hr Ed enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Scalable Clustering nov ice t o ex pert . The Cisco caching solut ion w as designed t o enab le net w ork ad m in ist r at or s t o easily clust er cach e New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP engines t o scale h igh t r aff ic load s. This design appr oach allow s cust om er s t o linear ly scale per forCov m ance or aget echn as cache englik ineesopt are added. For ex and am ple, single Cisco Cach e eragand e of cache cut t ingstedge ologies ical n et wor k ing st oraage En gine 5 90 can sup por t a 45- Mbps WAN link and 1 44 GB of cache st or age; ad ding a second Cisco Aut Cache Engin e 590 Sy p rov ides supp ortide f or leader a 9 0- Mb lin k fand 288I nGB h ored by Cisco st ems, w or ldw in ps netWAN w or king or t he t er nof et .cach e st orag e. Up t o 32 cache engin es can be clust er ed t oget h er . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat This linear ach iev ed bt oecause of and t h e an m anner in wen hich W CCPenab erwsork redir enables netscalabilit w or kin g yp risofessionals un derst d im plem t cont em por ar yled int rerout net ingect tt rechnologies. aff ic t o cacheMast enger ines. WCCPenab led r out er s per for m a hashing fu nct ion on t h e incom in g t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing rindu eq uest d est n inat ion t o I Pincor ad drpor ess, g twhe equest int olog o one e bu env cketirs.onm ent . st ry's. Lear how at m e app int erinnet orrkin g t echn iesofin2t 56 o a discr LAN/etWAN St at ist ically , t h is hashing fu nct ion d ist r ibu t es incomin g r equest s ev en ly acr oss all ck et s. I ny, Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g,buscalabilit add it ion , t hese bu ck et s ar e evenly allocat ed am ong all cache eng ines in a clu st er . WCCPand speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t enabled ial t o all rnet outwer ensur e tessionals, hat a cert ain cache det erm orskin g p rof r egar dlessengin of exepert ise. inist ically f ulf ills r equest s f or a cert ain dest inat ion I P add ress on t he I nt er net . Em pirically, t his dist r ibut ion algor it hm has consist en t ly dem onst evain en aload dist ionstacross en gine clust h et icu popu lart hWeb sit es Reader s rwatilledobt g reat err ib unutder an ding aofcache LAN and WAN n eter. w orMost k ing,ofp tar lar ly e hav e marult P addr and esses, s prinv event in .g Fu u neven load ist r ibu t ion.inf or mat ion is pr ov ided on har dw e,iple pr otI ocols, sertvhu ices olv ed ndam ent al dt ech nology a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions When cu stcept om ercomp add rseh a en n ew cach e en t o tand he clust erional , t he rWCCPenab r out t o en sut he re con sion and r etgine en t ion, ad dit esou r ces f orled fu rt hererstdet udyect . s tCov he erag pr esence of t he cach en gine d reallocat es t concep he 25 6 tbs,ucket s t o accomm e t he e is also ext new end ed n ote only t o an new n et wor k ing but also t o old er ,odat legacy add ions,alprcache ex amicple, heesim instwallat on een rou er and systitem ovid inengine. g a m orFor e r ealist picttur of tplest he realor ldion n etuwsing or k ing virt onm entone s in cache w hich engine assign soper all at 25e.6 Tools b ucketand s t ogu t he sing le fcach e im en izing gine. syst I f a em custper omfor er m add s anot er cache pr of essionals id elines or opt ance w illhincr ease engine, t he t er redir ecting s packet s t o t he t w omor cach en ly—1 28 pr odu ct iv it y WCCPan d imen prabled ov e effr ou iciency, help t he r eader m ake e einengines t elligent ev , cost - eff icient bu ck et s arfor e allocat ed w t oork each decisions t h eir net s. cach e en gine. I f t he cust om er add s a t h ird cache engin e, t he WCCP- en abled r out er assigns 85 or 86 bu ck et s t o each of t he t hr ee cache eng ines. Cu st om er s can h ot - inser t cach e en gines int o a f ully oper at ing cach e clu st er . I n t his sit uat ion , t he WCCP- en abled r out er aut om at ically r eallocat es t h e buck et s ev enly am ong all cache clust er m em b er s, includin g t h e new cache eng in e. Because a new cache engine w ill not h ave any cont ent , it w ill incur f r eq uent cache m isses u nt il enou gh con t ent h as been p opulat ed in it s local

st or age. To alleviat e t his cold st ar t up p rob lem , t h e new cache engin e, for an init ial p er iod, send s a m essag e t o t he ot h er cache clust er m em b er s t o see if t h ey h ave t he r equest ed cont ent . I f t hey hav e t h e con t ent , t h ey will send it t o t he new cach e engine. Once t he n ew cach e en gine det er min es it has r et r iev ed enou gh cont ent fr om it s p eer s ( based on conf igur able n um ber s) , it w ill han dle cach e m isses by d ir ect ly requ est ing t h e cont ent fr om t h e en d ser ver r at her t h an fr om it s peer s. •

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Fault Tolerance • I ndex and Fail Safety I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

IByf any engin Ciscocache Systems, Inc.e in a cach e clu st er f ails, t he clust er aut om at ically heals it self. The WCCPenabled rou t er r ed ist r ibut es t he f ailed cache en gine's load evenly am on g t he r em ainin g cache engines. The cache clust er cont in ues operat ion u sing on e less cache engin e, but oper at ion is Pub lish er: Cisco Press ot her w ise u naf fect ed . Pub Dat e: Sep tem ber 1 1, 2 003 I SBN:net 1- 58 19 -2 The Cisco w 705 ork-1caching solut ion en ables an WCCP- enab led , Mult igr ou p Hot - St andb y Rout er Pr ot ocol Pages: ( MHSRP) 11 28 r out er pair t o shar e a cache eng ine clust er , cr eat ing a f ully r ed und ant caching syst em . This is r efer r ed t o as WCCPm ult ih om ing . I f t he WCCP- enab led r out er f ails, ex ist ing Cisco I OS f ault t oler ance an d f ail- saf e m ech anism s ar e ap plied . For exam ple, a hot - st and by r out er could dy nam ically t ak e ov er oper at ions, r ed irect ing Web r equest s t o t he cache clust er.

I f an en t ir e cache clust er fails, t h e WCCP- enab led r out er au t omat ically st ops r edir ect ing t r af fic t o The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t he cache clust er , sen ding client s' Web r eq uest s t o t h e act ual d est inat ion Web sit e in t h e essent ial an d cu t t ing- edg e t ech nologies. t r adit ional fashion. This loss of t he ent ir e cache clust er can ap pear t o u ser s as an incr ease in dow n load t im e f or Web cont en t , bu t h as no ot her sig nificant eff ect . Th is desig ned- in, f ailsaf e r espon se cise is mov ade not kdir in line als w it hatclient s' els, ot h er Con er vpossible iew s of tbecause echn ologt he ies cache essen tclust ial t oern is et wor ingectprlyofession all lev f rom net w or k t r aff ic. nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

WCCP Multihome Router Support

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

As pr ev sly mby entCisco ion edSy , t st heems, Cisco n et wor k caching ion en ables cache Autiou h ored w or ldw ide leader insolut net w or king f or tahe I n t ereng n et .in e clu st er t o hom e t o m ult iple WCCP- enabled rou t er s f or add ed r edun dancy . Thu s, Web t r af fic f rom all of t he WCCP hom er s wnologies ill be redir ectbook ed t o, tFour he cache expr am ple, a cache clu st er I n t ern et w orek rinou g tTech Hand t h Ed itclust ion ,er. is aFor com ehensive refer engin ence tehat tenables hat is hom ing t o bot h r out er s in a MHSRP r out er pair cr eat es a fu lly redu ndan t caching syst em , net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing elim inat in g an y sin gle poin t s of failur e ( Figur e 54 7) . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all 5 4essionals, -7 . Ful ly Redu t Ca che En gin e Cl ust e r Conf ig ur a t i on net wFigu or kin gr e p rof r egar dlessnd of an ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

Overload nov iceBypass t o ex pert .

New er s include covge, erag of imeng por tine antclust t opics likeldVoI P ande EAP Wit h a sudchapt den Web t r aff ic sur a ecache er cou b ecom ov er loaded. To gr acefully han dle t his ov er load sit uat ion, each cach e engine det ect s w h en it is over load ed , r efuses Covalerag e of cut t ing for edge echn ologies n etser wor k ing and st orinage add it ion r equest s, and w artds t h em t o t hlik e eoropt ig inical Web v er s. Th e orig Web ser v er s r espon d dir ect ly t o t he clien t s because t he b yp assed requ est s wer e not han dled b y a cache Aut h orede by engine ( Figur 54 -Cisco 8) . Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Figu r e 5 4 -8 . O ve r loa d Bypa ss indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The ov er load cache nov ice ted o ex pert . engin e w ill resum e accep t ing requ est s w h en it det er m ines t hat it h as t he r esour ces t o d o so w it h out ret r igger ing over load b yp ass in t h e near f ut ur e. The over load b yp ass chapt eres aut include erag e er ofmim por by t antCPU t opics andload. EAPI n t he ex t r eme on/ of fNew t r igger s ar om at cov ically det ined an dlike f ile VoI systPem sit uat ion t hat t he cache eng in e becomes so over loaded t h at it is unab le t o r espond t o t he b asic erag e of ing edgef rt om echnitologies e opt et wor khom ing eand ster or age WCCPCov st at us ch eckcut mtessages s hom e lik r out er , ical t h e nWCCP r out w ill r em ove t h e cach e engine fr om t h e clu st er an d r eallocat e it s buck et s. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Thu s, over load b yp ass en su res t h at a cach e en gine clust er does n ot int r od uce abnor m al lat encies Iand n t ern w or k in gnet Tech nologies Hand book ,und Four Edsu it ion a com pricehensive refer ence t hat m et aint ains w ork av ailabilit y even ert hunu ally, is high t r aff con dit ions. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Dynamic Client Bypass Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Som esessionals, r equir e client s tdless o b e of autex hent icat ed using t he clien t 's I P addr ess. Howev er , wh en net weorWeb kin g sit p rof r egar pert ise. a n et wor k cache is in ser t ed b et w een a client and a Web serv er, t he Web ser v er only sees t h e cach e' ssI w P ill adobt dr ess d reat not er t heunclient P addr Reader ain an ag der st's anI ding ofess. LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on To er com e et hof is int issue and sim ilar sit uat ions, t hin e clud Cisco Engine has a dy ic client a b ov r oad r ang egr al sy st em s and serv ices, ingCache det ailed descr ipt ion s,nam rev iew quest ions by f eat ur e t hatcomp ef fect ively allow s client u nder condritesou ion s,r ces t o bf yp eng.ines t o pass en su re con cept r eh en sion and r et ens,t ion, andcert ad ain dit ional or ass fu rt cache her st udy and dir ect con nect t o origin er s. nThe r esult t hat at s, Cisco Cache can p reser v e Cov erag e ly is also ext end ed n otWeb only ser t o vnew et wor k ing isconcep but also t o Engin old er e , legacy exist ings,sour ce IinPgaut h en ion m t h r ough v er erkring or menessages t o client syst em pr ovid am or teicat r ealist ic odels pict urand e of pass t he realw or ldser n et w or vir onm ent s in ws.hich Becau se t he cache engin e dy and nam gu ically ad aptf or s t oopt t hese sit usyst at ions, lessfor man agement is rease equir ed pr of essionals oper at e. Tools id elines im izing em per m ance w ill incr tpr o odu en su ranprspovarency . ct re iv itcache y an d tim e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Dynamic Client Bypass Function I n Figur e 54 - 9, a client issues a Web r equest , w hich is r ed ir ect ed t o a cache engin e. I f t h e cach e engine does not hav e t he con t en t , it will t ry t o f et ch t he cont en t f rom t he or igin Web ser ver .

Figu r e 5 4 -9 . D yn am i c Cli en t Byp ass

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom I n Figur e ice 54 - t10, t h e. ser v er r espond s t o t h e cach e engine wit h cert ain HTTP er r or r et u r n codes nov o exifpert ( such as 401 - Un aut h orized requ est , 403 - For bid den, or 5 03- Ser vice Unav ailab le) , t he cache New cov e of porfteat antu tropics VoI and EAP engine w illchapt in vokerest hinclude e dy nam icerag client byim pass e. Thelike cach eP engine will d yn am ically st or e a client I P- dest inat ion I P addr ess by pass pair , so t hat fut u r e packet s w it h t his I P addr ess pair w ill Cov e of cutgine. t ing edge t echn ologies lik e opt et wor and age by pass t herag e cach e en Th e cache en gine sends anical aunt om at ick ing HTTP r etstryormessag e t o t he client 's b row ser. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Figu r e 5 4 -1 0 . Dy na m ic Cl ie nt By pa ss t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. I n Figur Con e 54 cise - 11, ov er w vhen iew tshe of client t echn' solog br ow iesser essen au ttom ial at t oically n et wor issu k ing es aprr ofession eload , t he alsrequ at all estlevwels, ill be f rom r ed irect nov ed icet ot ot he ex cache pert . eng ine. How ev er , w hen t he by pass t ab le is check ed an d t he r equest m at ches one of t h e t able ent r ies, t he cache eng in e w ill r ef use t he r equ est and send it dir ect ly t o New chaptser er sv include cov erag e of Web im porser t ant liket he VoIclient P and' s EAP t he orig in Web er . Th us, t he origin v ert opics w ill see I P add ress, aut h en t icat e t he client , an d respond dir ect ly t o t h e client . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

Figu r e 5 4 -1 1 . Dy na m ic Cl ie nt By pa ss

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Reverse Proxy Caching Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom ice t o ex . Cachenov eng ines ar epert fr equent ly d ep loyed near by client s t o ensur e f ast er net w ork r esponse t im e and m inim al WAN bandw id t h u sag e. Thus, t he cach es are caching t h e client s' m ost f requ en t ly New cont chapt er. sI ninclude cov erag e of im por t ant also t opics VoI P and accessed ent add it ion, cache engin es can be like deployed in f rEAP ont of Web serv er far m s t o in cr ease t he ser ver f arm cap acit y and imp rov e Web sit e perf or man ce. Th is config ur at ion is t ing edge t echn ologies lik e eng opt ical et ewor k ing and or age calledCov r everag erseepof roxcut y caching because t he cache inesnar only cach ingst con t ent f r om t he ser v ers f or w hom t hey ar e act ing as a f r ont - end. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . This f eat ur e is par t icular ly im p ort an t w h en cach e engines ar e act ing as a fr ont - end f or ser v er I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat far m s in w hich cer t ain cont en t is dr am at ically mor e p opular t h an ot her cont ent on t he ser v ers. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Using r ever se- p rox y caching allow s adm inist rat ors t o pr ev en t a sm all n um ber high - dem and t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing URLs f r om im pact ing over all ser v er per for m ance. Bet t er y et , t h is means t he h ig h- dem and URLs indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . do not hav e t o b e ident if ied, man ually r ep licat ed, or independ en t ly man aged fr om t h e bulk of t h e Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, URLs on t h e ser v er s. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w illProxy obt ain aCaching g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Reverse Function har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a r oader 54 ang e ofeach int egr al sy st emine s and in clud ingled detrailed ion s, revar iew I nbFigur - 12, cache eng homserv es tices, o WCCPenab out erdescr s/ sw itipt ches t hat e quest ions tsupp o enort su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her udy in g ser ver f ar ms. Wh en an incom ing Web r equest r eaches an WCCP- enab led rst out er., t he Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy r out er per for m s a hashing fu nct ion on t h e incom in g requ est ' s sour ce I P addr ess and por t syst em prap ovid in gt he a mr equ or e est r ealist pict of tdhe realor ldetns. et w ing en vir ent s in w hich nu mb ers,, m ping in t oicon e ur of e256 iscr et e wbuck Stor atkist ically , t onm his hashing pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill fu nct ion dist rib ut es incom in g r equ est s ev en ly acr oss all b ucket s. I n addit ion, t hese incr buckease et s are pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient evenly allocat ed am ong all cache eng ines in a clu st er . decisions for t h eir net w ork s.

Figu r e 5 4 -1 2 . Re ve r se Pr ox y Ca ch in g

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Table of Content s

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I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Becau se t he hash in g f un ct ion is based on sour ce I P ad dr ess an d p or t nu m ber inst ead of nov ice t o ex pert . dest inat ion I P add ress, a g iv en Web ob ject could be st or ed in m ult iple cache engin es in a clust er . By spr eading pop ular cont ent acr oss a cache clust er , r ev erse p rox y caching allow s m ult iple cach e New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP engines t o ser v ice requ est s f or v er y p opular cont en t . Thu s, addit ional cache en gines can b e add edCov t o erag a clust er cut t o tin cr em en ttally t helik perf or man ceetof a kpop e of ing edge echnscale ologies e opt ical n wor ingular and sit st eorand age decrease cont ent dow n load lat ency . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Not e t h at h ash in g on a dest inat ion I P addr ess could also do t h e r ev er se- pr ox y cach ing. Bu t in tI his case, allk in r eq w ould hav e t he sam e dest r ess w ouldrefer be redir ed t o n t ern et w or g uest Techsnologies Hand book , Four t h inat Ed ition ion ,I P is add a com prand ehensive enceect t hat one cache eng ine. I f you do not need t o scale b ey ond one cache eng ine act as a f ron t end a enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w orkt oing ser v er far m , t h en t his m et hod is suf ficien t . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Ensuring Fresh Content A r equ ir em en t f or any caching sy st em is t h e abilit y t o en su re t hat user s see t he sam e cont ent fr om a net w or k cach e as t hey w ou ld f rom t he Web. Ev er y Web pag e com p rises sev er al Web obj ect s and each Web ob ject h as it s ow n cachin g p aram et ers, d et er m ined b y cont ent aut hor s •and HTTP st an Table dar of dsContent ( see t she " HTTP Cach ing St andar ds" sect ion) . Th us, even a Web pag e w it h •r eal- t im e ob ject I ndex s t y pically h as m any ot h er ob ject s t hat ar e cach eab le. Rot at ing ad bann er s an d ICom nt e rnmeton w orGat k ingew Teay chnologie s H a ndbook that Edit I nt erf ace ( CGI ) -, gFour en er edion responses ar e exam ples of obj ect s t hat are t y pically noncacheable. Toolbar s, nav ig at ion bar s, GI Fs, an d JPEGs ar e ex amp les of ob ject s t hat By Cisco Systems, Inc. ar e t y pically cacheable. Thu s, for a giv en Web page, on ly a f ew dy nam ic obj ect s n eed t o b e r et riev ed fr om t he end ser v er , w h ile st at ic object s can be f ulfilled locally . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 Cisco Cache Engin e pr odu ct s deliv er fr esh cont ent by obeying t h e HTTP caching st andar ds and I SBN: 58 705 -1adm 19 -2 in ist r at or s t o hav e cont r ol ov er w hen con t en t shou ld b e r ef r eshed fr om by enab lin g1-cache 11 28 ers. or igin Pages: Web serv

HTTP Caching Standards The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of HTTP 1 . 0 an d 1 . 1 ar e caching st andar d s, wh ich specif y cach ing par am et er s f or each obj ect on a essent ial an d cu t t ing- edg e t ech nologies. Web page. HTTP 1 . 0 allow s cont ent aut h ors t o enable a " Pr agm a: n o cache" h ead er field f or any ob ject t h at Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom should not be cached and allow s aut hor s t o enable cont ent t o be cach ed ind ef init ely. nov ice t o ex pert . HTTP 1 . 1 allow s cont ent aut h ors t o specif y how long con t ent is t o be cached. For each obj ect on New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP a W eb pag e, con t ent au t hor s can ch oose amon g t he f ollow ing caching at t r ibut es: Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Noncacheable Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . OK t o cache ( t h e defau lt set t ing) I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Ex plicit ex pirat ion d at e t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu n fhow t oess incor por at eion int er or kin gcalled t echnIolog ies ied in t o- Since a LAN/ ir onm HTTPst1ry. 1. Lear h as a r eshn r evalidat mnet echwanism f - Modif ( IWAN MS) tenv o ensur e ent t hat. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, cach ed d at a is u p t o dat e. A cach e en gine w ill send a ligh t w eigh t I MS requ est t o t h e end Web and speed, t h is book is a com plet e an d u pt od at e r ef er ence t o t he t op ics t hat are essen t ial ser v er w hen t he cach e engine receiv es r eq uest s for cached con t en t t h at h as exp ir ed or I MS t o all net or kin p rof essionals, of ex r eq w uest s frgom clien t s w herreegar t he dless cached conpert t entise. is m or e t h an a config ur ed per cen t age of it s m axim um age. I f t he ob ject has not been m odified on t he end ser v er sin ce t he obj ect w as Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e cach ed , t he en d ser ver w ill r et ur n a light w eight m essage in dicat in g t hat t he cache engin e can har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on deliver it s cached cop y t o client s. I f t he ob ject has been m odif ied on t he end ser v er sin ce t he a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions obj ect w as cach ed , t he en d serv er w ill r et ur n t his inf orm at ion t o t he cach e engine. I f t h e case of t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . t he client issuing an I MS r equest , an d t h e cont ent is less t h an a config ur ed per cen t age of it s Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy m axim um age, t he cache will ser ve t he cont ent w it hout check ing if it is f resh. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Cache Content Freshness Controls decisions Engine for t h eir net w ork s. Adm inist r at or s can cont r ol t he f reshness of Web object s in a cache engin e by conf igur ing a par am et er called t he fr eshness fact or , w hich det erm ines h ow fast or slow cont ent ex pir es. When an obj ect is st or ed in t h e cach e, it s t im e- t o- liv e ( TTL) v alue is calcu lat ed using t h e follow ing for m ula:

TTL v alu e = ( Cur rent dat e - last m odif ied dat e) * Conf ig ur able f reshness f act or When an obj ect ex pir es, b ased on it s TTL valu e, t he cache engin e w ill issue an I MS requ est t he nex t t im e t h e obj ect is requ est ed ( see " HTTP Cach ing St andar ds" sect ion f or a descr ipt ion of t he I MS p rocess) . I f an adm in ist r at or wan t s t o adopt a conser vat iv e f reshness policy, he or she can set t h e fr or t oofaContent sm all sv alue ( such as 0. 05 ) , so t h at ob ject s exp ir e m or e qu ick ly. But t he • eshness fact Table disadv ant ag e t o t his app roach is t hat I MS r equest s w ill be issued mor e f requ en t ly, con su m in g • I ndex ext r a band w id t h. I f an adm inist r at or w ant s t o adop t a liberal fr esh ness policy , t h e fr esh f act or I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion can be set t o a lar ger v alu e, so t hat obj ect s w ill ex pir e m ore slow ly and t h e I MS ban dw idt h By Systems, ov Cisco er head w ill beInc. sm aller . Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 Browser Freshness Controls I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 Finally, client s can alway s ex plicit ly r efr esh cont ent at any t im e by u sin g t he br ow ser ' s r eload / ref resh but t on .

The re l oa d/ r ef re sh com m and is a b r owser - t r ig gered comm an d t o r eq uest a dat a r efr esh. A re l oa d/ r ef re sh w ill issue a ser ies of I MS r eq uest s ask ing for only dat a t hat has ch anged. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of The shif r edloa shifedg t+ e r ef re sh com m and is an ex t ension of t he re l oa d/ r ef re sh com m and. essent ialt +an cu d/ t t ingt ech nologies. I n cor r ect ly im plem en t ed b row sers, t h is comm and alw ay s t r igger s a " p rag m a: no cach e" r at her t han an I MS r equ est . As a r esult , cache en gines ar e by passed and t h e end ser ver d irect ly fu lf ills all cont Con ent cise . ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include Summary

cov erag e of im por t ant t opics like VoI P and EAP

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Mu ch of t he t raf fic on t h e Web is redu ndan t , m ean ing t hat user s in t h e sam e locat ion oft en Aut h ored Cisco or ldw ide leader w or kingpor f ort ion t he of I n trecur er n etr .in g access t he sam by e cont entSy ovsterems, and wover . Elim inat ing in a net sig nificant t elecom m unicat ions of fer s hu ge savin gs t o en t erp rise and serv ice pr ov id er s. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net p r ofessionals t o frun derst an d im plem ar yion int er net wt oork Caching is t w h eortkin echgniqu e of keeping equ en tand ly accessed inforen mtatcont ion em in apor locat close t hing e t hebenefit t er m s,s ar con rt echnologies. eq uest er . Th eMast t w oerk ey e:cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Cost t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all and speed, net w or kin g p rof essionals, r egar dless of ex pert ise. I m pr oved usabilit y Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Ihar m plem t echnology net acceler cont ent deliv ery , op t imisizes WAN dw arent e, ing pr otcaching ocols, and ser v ices in invaolv edw. ork Fu ndam entat alest ech nology inf or mat ion pr ov ided on ban dw idt h, and enables cont ent mon it orin g. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cisco has cr eat ed a net w or k- int eg rat ed cach e engine by pair ing syst em - lev el soft w ar e and Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy har dw ar e. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

On w hat concep t is n et w or k caching based?

2:

I ndex ar e t w o secondar y benef it s of imp lem ent ing caching t ech nology ? What

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Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 : Pr ovid By Cisco Systems, Inc. e 4:

a b rief descr ipt ion of net w or k- in t eg rat ed cach ing t ech nology .

How d o Cisco cache engin es ensur e t h at w eb pages ar e k ept u p t o d at e?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

Nam e an object t hat can be sav ed in cach e m em or y , and one t hat can not .

I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 55. Storage Networking Obj e ct i ve s • •

Table of Content s

Becom e f am iliar w it h st or age net w or k in g an d it s pur pose. I ndex

I nt e rn Becom et w or k ing ndbook Fouren th tEdit e f Te amchnologie iliar w itshHtahe com,pon s ofion a

st or age net w ork .

By Cisco Systems, Inc.

Becom e f am iliar w it h t he Fibr e Chann el pr ot ocol. Pub lish er: Cisco Press

Becom e f am iliar w it h t he iSCSI pr ot ocol.

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 19 -2om at ion, I T org anizat ions cont in ue t o seek new m et hod s, lev erag in g I n t oday 's w1-or58ld705of-1 aut t echnology Pages: t11 o28 opt im ize b usin ess p rocesses and r educe ov erall cost s. Gon e ar e t he d ays of v isit in g a b ank t eller and hav ing you r t r ansact ions r ecor ded in a led ger . I nst ead , m or e and m ore bu sin ess pr ocesses and ser v ices ar e b eing m igr at ed t o com put er ap plicat ion s, off er ing fast er ser v ice, g reat er access, bet t er av ailabilit y , an d less- ex pensiv e operat ion . Today , y ou can ex ecut e ban k t r ansact ion s fr om an ATM, a w eb br owser , a t elephon e, and ev en a PDA. How ev er , t he cont al dev elopm m en tallof incom putnet er w apork plicat especially I n t ercover net - fage acin of g The inu u pdat ed edit ionent of tand he bdeploy est - selling one ing ion r efs, erence p rov ides app licat ions, r esu lt s in ex or bit ant am ount s of dat a bein g cr eat ed at a r apid pace. I n addit ion, t he essent ial an d cu t t ing- edg e t ech nologies. av ailab ilit y an d mob ilit y requ ir em en t s of such dat a cont in ue t o gr ow . Faced w it h t he challenge of deploy ing and m anagin g lar ge am ou nt s of st or ed d at a, I T or gan izat ion s ar e chang in g t he w ay in w hichCon st orcise ageov iserdeploy and m ain t ained. v iew s ed of, taccessed, echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . I n t he past , most deploy ed st or age w as d ir ect ly at t ached ( in t h e dir ect - at t ach ed st or age [ DAS] m odel) t o chapt t he aperplicat ion serv requ it . t ant Thist opics at t achm comEAP m only m ade over a New s include covers erag e ofirin imgpor likeent VoIwas P and par allel SCSI conn ect ion, alt h ough som e r elat iv ely newer inst allat ions m igh t h ave used dir ect ( poin tCov - t o-erag point e )ofFibr cutet ing Chan edge nel loop t echncon ologies nect ivlik it ey .opt How ical ever n et, wor t he kDAS ing and m odel st orpage resen t ed ineff iciencies in t er m s of per for m ance, pr ovisioning f lex ibilit y, an d cost . By it s nat ur e, DAS w as Aut bysole Cisco w or ldwion ideser leader w or ort ach t heed I n.t er n etm . ade it dif ficult dedicat edh ored t o the u seSyofst tems, he app licat v er t oinwnet h ich it king w as fat This t o add new capacit y or r edeploy un used capacit y . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat net w kin g pinr ef ofessionals unAS derst and posed an d imaddit plemional en t cont ar y int Ienables n addit ion t oort hese ficien cies, t ao D m odel costem s bpor ecause ofer t hnet e rw eqork uiring ed t echnologies. er erou t he ts,er and m s, oft conen cep t s,erog t echn an d edevices in ted oday ' s net w ork m anagem ent Mast of n um het en ologies, eou s, st orag dev icesused deploy t h rou ghou t t ing he indua stcen ry .t er Lear n how, t o por e int er net or kin g tban echn t o a by LAN/ WAN env ir onm . e dat . Finally heincor direct lyatconnect ed w chan nel dwolog idt hies offin ered a par allel SCSI orent Fibr Com plet eloop w it hconnect new anion d uwpdat edared chapt erong s on all secur y , ston or age, net .wThe or k inshar g, scalabilit y, Ch annel as sh am devitices t he bopt us ical or loop edand dw speed, t hodel is book plet eber an of d ustp-ort od atdeevr ices ef er ence t o t he be t opaccessed ics t hat are t ial t o all ban idt h m lim itiseda tcom he num age t hat could andessen t he ov erall netailab w or kin g p rof r egar dless of ex pert ise. av le band wessionals, id t h.

Reader w illt he obtim ainm ain genreat un der st an ding m of any LANI Tand WAN n ions et w orcon k ing, p art toicu e ay To ad drsess t ster or age challenge, or ganizat t inue m lar igrly at et haw har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov fr om t he DAS m odel t o a st or age ar ea net w or k ( SAN) m odel. By op en ly net w ork ing blockided on a b r age oad dev r angices e ofwint al sy stion em ser s and ices, clud ing descr ipt ion rev iew st or it hegr applicat ver serv s, sev eralinadv ant agdet es ailed ar e r ealized. Thes,SAN br inquest gs ions tcapabilit o en su reies con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . t o st or age, includ in g a m or e gr anular pr ovisioning and m igr at ion mod el. Th is allows Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy qu ick er deploy ment and r edeploym ent and a m or e eff icient use of st or age. The SAN also syst s, pr inralized g a m orpoint e r ealist pict ur e solid of t he realw or ld nr esou et w orrces, k ing including en vir onmdisk ent s an in dwthich r ep rem esent s aovid cent at wichich con at ed st or age ap e, pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease can be m anaged m ore ef ficien t ly. Figur e 55 - 1 sh ows t he com ponent s and layou t of a t yp ical pr odu ct ivnet it ywan eff iciency, ing t hewror eader ake mor t elligent effan icient st or age or d k . im Aspryov ouecan see, a sthelp orag e net k canmconsist ofe ainlocal dat a, cost cent-er d decisions for t h eir net w ork s. r em ot e con nect iv it y ov er met r o- ar ea net w or ks ( MANs) or w ide- ar ea net w or ks ( WANs) .

Figu r e 5 5 -1 . St or ag e Ne t w or ki ng M ode l

•

Table of Content s

•

I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

What Is a SAN? ASAN is a com mu nicat ion n et w or k u sed t o conn ect com p ut ing dev ices, such as applicat ion host s, t o st orag e dev ices, su ch as disk and t ape ar r ays. I n a com m on st or ag e net w ork ing t er min olog y der iv ed fr om t h e SCSI pr ot ocol, t h e users of st or age are called init iat or s, an d t he •block st or ageTable of Content s dev ices ar e called t ar get s. •

I ndex

IThe nt e rn et w or ingary Te chnologie H a ndbook Four th Edit ion t o bu ild a SAN ar e Fib re Chann el and SCSI ov er t wo prkim com m uns icat ion pr, ot ocols used TCP/ I P, or iSCSI . Fib re Chann el is pr edom in ant ly t h e pr ot ocol of choice, becau se it has b een in By Cisco Systems, Inc. exist ence for som e t im e. How ever , iSCSI , now a r at ified I ETF st andar d, let s you bu ild a SAN using a less- cost ly Et hern et inf rast r uct ur e. Figur e 55 - 2 sh ows t he init iat or - t ar get com m unicat ion Pub lish er: Cisco Press m odel as it r elat es t o bot h Fib re Chan nel and iSCSI SANs. I n t he case of iSCSI , m ost com mon Pub Dat e: Sep tem ber 1 1, 2 003 im plem ent at ion s include a gat ew ay f unct ion t hat br idges an iSCSI Et hern et inf rast r uct ur e in t o a I SBN: nel 1- 58inf 705rast -1 19r -2 Fibr e Chan uct ur e. Th is hy br id SAN in fr ast r uct ur e r esult s fr om t h e cu r rent lack of 11 28t hat nat iv ely sup por t iSCSI . Th e pr im ary focus of t h is ch apt er is Fibr e Chan nel, t ar get Pages: d ev ices alt hou gh an in t r oduct ion t o iSCSI is pr esent ed.

Figu e 5- selling 5 -2 . SCSI Com u niing cat M ode The u pdat ed edit ion of t he br est all- in- one netm w ork r efion erence p rovlides cover age of essent ial an d cu t t ing- edg e t ech nologies. [ View full size im age]

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . A SAN isebuilt om aanser ofed Fibr e Chann el or Et hitery net swage, it ches, net wnet or ked er ent Com plet w it h frnew d uies pdat chapt er s on secur , st or opt ical w or kinindg,iffscalabilit y, tand opolog ies t o bu ild lar ger net w or ks wit h hig her por t densit ies. I n Fibr e Chann el, an ind ividu speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial al t o all sw is called fab r ic, anr degar a connect r oupise. of sw it ches is also called a fab r ic. Th e t erm netitwch or kin g p rofaessionals, dless ofedexgpert Et h er n et fab ric is oft en used t o ref er t o an Et h er net net w or k used t o build an iSCSI SAN. This chapt ers uwses t h eain t erm o rder eferst tan o ding a connect ed and g rouWAN p of sw in a pSAN. Reader ill obt a gfab reatr ic er t un of LAN n etitwches or k ing, ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on The p ur pose ofof a int SAN a f lex ible andincen alized m ean descr s of con nects,ivrev it y ,iew such t hations a b r oad r ang e egrisalt osypstr ovide em s and serv ices, cludt ring det ailed ipt ion quest nurem con berscept of incomp it iat ors gain access lar gand e num berional s of trar getrs. This etrtwor m .odel tlar o ge en su r eh can en sion and r et enttoion, ad dit esou ces f or nfu herk ing st udy r esem bles clienext t / ser v er of net w orkning r at her an a peert o- also peer t m Cov erag e isa also end edmod n ot el only t o new et wor k ingt hconcep t s, but o od oldel. er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich A SAN is m uchoper lik eatany ot herand dat agucom m un icat netizing w or k,syst inclu anmI P net wwor , in ease t hat it pr of essionals e. Tools id elines f or ion opt im emding per for ance illkincr possesses t he f ollowin g char act erist ics: pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Mu lt i pl e prot ocol opt i ons— Alt hough t h e pr edom inant ly u sed comm u nicat ion pr ot ocol is Fibr e Chan nel, ot her st or age n et w or k ing pr ot ocols ex ist includin g I BM' s ESCON, FI CON, and SSA. iSCSI is a new comer t o st or age net w or k in g t hat offer s lot s of b en ef it s in t er m s of inf rast r uct ur e cost an d man ageabilit y.

Mu lt i pl e con ne ct i vi t y opt i ons— A st or age net w or k possesses m ult iple connect ivit y opt ion s t hat depend on su ch f act ors as shar ed or d ed icat ed band w id t h, sp eed of connect ion, lengt h of conn ect ion, and connect ion m edia. For ex amp le, w it h Fibr e Chan nel, y ou can connect u sin g t h e ar bit r at ed- loop met h od ( shar ed) , t he f abr ic con nect m et hod ( dedicat ed) , copp er or fib er media, or at speeds of 1 Gb ps or 2 Gb ps. H ie ra rchi cal a ddr essin g sche m e — St orag e net w or ks, r egar dless of wh et her t hey use Fibr e Chan nel or iSCSI , lev er age a hier archical, assig ned ad dr ess schem e t o r out e dat a • Table of Content s fr am es bet w een end nod es. I n addit ion , SANs possess a dy nam ic r out ing pr ot ocol, such as • I ndex Fabr ic Shor t est Pat h Fir st ( FSPF) in Fibr e Chan nel. Such pr ot ocols dy nam ically bu ild I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion pr efer red pat h s w it hin a SAN an d pr ovid e alt er nat iv e r out in g if a lin k in t he net w or k fails. By Cisco Systems, Inc.

I nt e gr at e d ne t w ork se cu ri t y— St orag e net w or ks, lik e ot her com m unicat ion net w ork s, at ePress feat u res t o select iv ely r est r ict v isibilit y an d com m unicat ion bet w een pair s of Pubincor lish er:por Cisco dev ices w it hin a com m on phy sical n et wor k . I n Fib re Chann el st orag e net w or king , t he Pub Dat e: Sep tem ber 1 1, 2 003 concep t of zoning is used t o rest r ict v isibilit y and com mu nicat ion t o only n odes t hat ar e I SBN: 1- 58 705 -1 19 -2 assig ned t o t he sam e zon e. Wit hin an iSCSI SAN, m echan ism s u sed t o secu r e I P net w or ks, Pages: 11 28 such as access cont r ol list s, can also be used t o secur e iSCSI d ev ices. N e t w ork - b ase d f low con t rol— As w it h an y net w or k, over su bscript ion is p art of all st or age net w or k designs. I t is alw ay s p resen t b ecause it is t oo cost ly t o elim in at e it f r om a net w or k. Also, becau se of t he pr em ise t h at all com m unicat ion is bet w een init iat or s and ar get it ision v erof y unlik hat t heallt aringetone s can ain ount pofrov I /ides O t hat canage be of The utpdat eds, edit t he bely est -t selling netsust w ork ingt hreefam erence cover all edg init e iatt or s nologies. at t heir peak r at e. Ther ef or e, st or age net w ork s ar e designed w it h essentgener ial anatded cu bt tyingech ov er subscr ipt ion, u su ally in her it ed fr om t he chosen cor e- ed ge design m odel. Howev er , t her e ar e cases in w hich con gest ion can occur at poin t s of consolid at ion, such as up lin ks Con iew s of t echn t ial Fibr t o neetChan wor knel, ing pr atork alls,lev els, f rom fr omcise cor ov e ter o ved ge. St or age olog n et wies or essen k s using likofession e ot h er als net w possess nov ice t o ex pert . flow - cont r ol cap abilit ies u sing a buf fer cr ed it m ech anism t hat can t hr ot t le end devices t o help elim inat e p oin t s of congest ion. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP N e t w ork - b ase d p re fe re nt i al se rv ice— There are t im es w it hin net w or ks t hat you m ight Cov of ide cut tping t echn ologies optfic ical et wortkhe ingnet and st or age w anterag t o pe rov r ef edge er ent ial t reat m ent lik of et raf thn r ough w ork . Su ch t r eat m en t is oft en app lied t o g ive p r ef er ence t o cer t ain applicat ions and / or host s d ur ing t im es of Aut h ored by As Cisco stnems, ide leader netbuilt w or king or t he I n t ernel n etof . fer qu alit y of congest ion. w it hSy IP et w orwkor s,ldw st orag e net w in or ks w it h f Fibr e Chan ser v ice ( QoS) capab ilit ies, w hich allow pr ef er ent ial schedu lin g of f r ames b ased on a t agg ed I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat fr am e ident it y , t hereby m inim izing t he ef fect s of congest ion on app licat ion t r aff ic gener at ed enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing fr om ch osen host s. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu stHry Lear n how t o incor porm atode e intl— er net w or g t echn t o am LAN/ env ir in onm ent y .bri d com m uni ca t i on Two prkin im ary comolog m unies icatinion odelsWAN are used dat a . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, net w or kin g. On e comm on m odel is t h e dat agr am m od el, w h er eby d at a f ram es ar e simp ly and speed, h is book is anet com plet e itan d u pt o-assur d at e ance r ef er ence t he t op hat are for w ar tded int o t he w or k w hout any t h at ftroames w illicsmtak e it t o essen t heir t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. dest inat ion or t hat adequ at e r esour ces ex ist w it hin t h e net w ork t o h andle t h e inject ed d at a fr am es. I n dependent f orw ar ding d ecision s ar e m ade at each hop along t he pat h fr om Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e sour ce t o d est inat ion . The secon d mod el is t he chann el com m unicat ion m odel, w hereby a har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on dedicat ed ch annel is est ablish ed f rom sou r ce t o dest inat ion t o r eser v e r esour ces along a a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions chosen p at h f or t h e int ended comm u nicat ion . Many net w ork pr ot ocols act u ally use a h yb rid t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . of t he t w o m odels. Fib re Chann el, lik e TCP/ I P, r epr esent s a hy br id comm un icat ion m odel in Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy t hat a ch annel is cr eat ed fr om sou rce t o dest in at ion usin g a login pr oced ur e; how ev er , n o syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich r esour ces ar e gener ally d ed icat ed along t he chosen pat h. Each hop w it h in a Fib r e Chan nel pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease st or age net w or k , lik e a TCP/ I P n et wor k , m ak es in dependent for w ar ding decisions. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions t h eir w ork How ev er , for m any difnet fer en cess.b et w een a st or age net w or k and a t rad it ional I P d at a n et w or k m ust be r ecognized: Se nsit i v it y t o la t e ncy— The t r ansact ions t h at g en er ally t r avel ov er st or age net w or k s are sen sit iv e t o ex cessive amou nt s of lat ency . These t r ansact ion s, pr imar ily consist in g of SCSI

• •

com man ds, such as re a d an d w ri t e, ar e sy nchr onous t ran sact ions t hat are sequ en ced and t hat of t en depend on t he pr ev ious com m and t o com plet e bef ore t he nex t com m and is gener at ed. Because of t he h ig h rat es of I / O t hat can occur w it h in a st orag e net w or k, an y excessiv e incur r ed lat ency can sign if icant ly aff ect an applicat ion' s per for m ance. Therefor e, t he goal w it hin SANs is t o m in imize lat ency b y redu cin g t he nu mb er of hops bet w een t he sour ce and dest in at ion and giv in g p r ef er ent ial t reat m ent t o hig h- pr ior it y dat a fr am es at point s of con gest ion . This can be accom plish ed in bot h Fibr e Chan nel- and TCP/ I P- b ased st or ageTable net woforContent k s t hr oug h p rop er desig n an d t uning . s I ndex

I n- orde r de li ve ry re qui re m e nt — I t is a g en er al requ ir em en t t o ensur e t hat fr am es ar e deliver ed in or der fr om sour ce t o dest in at ion w it h in a st orag e net w or k w herev er possib le. Cisco AltSystems, hou gh frInc. am es are sequ en ced w it h f r ame num ber ing, som e d ev ices w it h in a st or ag e net w or k m ight not be ab le t o r eord er fr am es, or t hey m ig ht pot ent ially suff er a f ault fr am es be r eceiv ed ou t of or der . I n all cases, addit ional lat en cy is incur red Pubcondit lish er: ion Ciscoshould Press if fr am es hav e t o r eor der ed. Th er efor e, in d esign ing st or ag e net w ork s an d t he load Pub Dat e: Sep tem ber 1 1, b 2e 003 balancing of f ram es acr oss equ al pat hs or b und led link s, it is im por t ant t o t ry t o k eep I SBN: 1- 58 705 -1 19 -2 fr am es associat ed wit h t h e sam e SCSI exchan ge t r av eling dow n t h e sam e p at h.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By

Pages: 11 28

Log i n t o fa br ic— Bef ore ex chang es can be sent bet w een init iat or s and t ar get s, all d ev ices m ust log in t o t h e net w or k. Wit hin Fib re Chann el, t his login occu rs in t w o places. Dev ices m ust f ir st log in t o t he n et w or k , and t h en t h ey log in t o each ot her befor e d at a exch anges m ay occu r. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of er m onb ase d ef low rol— A un ique char act erist ic of a Fibr e Chann el st or age essentPial ani ssi d cu t t ingedg t ech cont nologies. net w or k is it s per m ission- b ased flow cont rol. Bef ore d ev ices can t r ansm it f r ames, t hey m ust r eceive perm ission or credit f r om t heir n eigh bor , w het her it be an ot her dev ice or t he Con er v.iew s of echn t iala tbu o nffet k ing prherw ofession net wcise or k ov it self This cr ted it isolog in ties he essen f or m of erwor cr edit , ot ise kals nowatn all as lev a r els, eceivf rom ernov ice t o ex pert . r ead y ( R_ RDY) or der ed set r eceiv ed f r om t he f abr ic. The bu ff er cr edit m echanism allow s dat a flow t o b e t hr ot t led as necessar y in a gr acefu l f ash ion if congest ion occur s w it hin t h e New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP fab r ic. Cov erag of cut t ing t echn e opt icalofntet k ing and stelorand age iSCSI pr ot ocols. The f ollow in g et wo sect ionsedge pr ovide a ologies det ailedlikaccount hewor Fibr e Chann Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Fibre Channel Protocol Dev elopm ent began on t he Fibr e Ch annel st an dar ds as ear ly as 19 88. The fir st Am er ican Nat ional St andar ds I n st it u t e ( ANSI ) st and ard w as ap pr oved in 199 4 an d w as nam ed t h e FC- PH st andar d ( ANSI X3. 2 30: 1 994 ) . Fib r e Chan nel as a t r anspor t p rot ocol w as pr im ar ily dev eloped t o •ov er com e t heTable Content s of t he cur r en t Sm all Com p ut er Sy st em I nt er face ( SCSI ) par allel shoroft com ings •inf rast r uct ur e, I ndex b ecause it repr esent ed a higher speed an d mor e- scalab le t ran sp or t . Alt houg h IFibr nt e rn w or knel ing Te chnologie s H asp ndbook th Edit ion e et Chan can also t ran or t ot, hFour er upper - lay er p r ot ocols, includ in g I n t elligent Periph er al I ntCisco er face ( I PI ) , Inc. High- Per for m ance Par allel I n t er f ace ( HI PPI ) , I P, an d I EEE 802 . 2, it is pr imar ily By Systems, used t oday t o t r anspor t SCSI com m and set s and dat a. Pub lish er: Cisco Press

Fibr e Chan nel is def in ed by t he ANSI T1 1 st an dar ds or gan izat ion as u sin g a layer ed ser vices Pub Dat e: Sep tem ber 1 1, 2 003 m odel. The ANSI FC- PH Ph ysical an d Signalin g I nt erf ace sp ecificat ion defines t h e Fib re Chann el 1- 58 705 19 -2 show n in Figur e 55 - 3. lay er edI SBN: ser vices m-1odel Pages: 11 28

Figu r e 5 5 -3 . La y er e d Ser v ices M ode l The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Each layer of t h is m odel pr ov id es a set of ser v ices, each r elying on t h e layer below an d ser ving t he lay er e.ain As ay ou caneralso see, Fibr e Chann el and was WAN developed sup por m ult Reader s wabov ill obt g reat un der st an ding of LAN n et w ort ok ing, p artt icu lariplylet hupper e lay er r ot How ever it isv ices pr iminv ar ily o pr t r anspor f or SCSI 3 pr ov ided on har dwpar e,ocols. pr ot ocols, and, ser olv used ed . Fut oday ndamtent alovid t eche nology inft or mat ion -is com mu nicat . int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions a b r oad r angion e of t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . The f ollow in galso list ext d escr layer shownnetinwor Figur 55 - 3: t s, but also t o old er , legacy Cov erag e is endibes ed neach ot only t o new k inge concep syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals operFCat e. gu idt he elines or opt syst em per for m wiet ill yincr FC- 0 — The 0 Tools layer dand ef ines p hy fsical inim t erizing f ace sp ecificat ions f orance a v ar of ease media pr oduand ct iv itassociat y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff ed receiv er s and t r ansm it t er s. Media t yp es may in clu de v ar iou s for m icient s of decisions for an t h eir net walong ork s. w it h sup por t ed line sp eeds. Connect ors, cab le t yp es, car r ier copper d f iber, signaling levels, and r at es are also defined at t h e FC- 0 layer . FC- 1 — This layer p rov ides t h ree p rim ar y fu nct ions. The f ir st is encoding and decoding dat a st r eam s. The 8B/ 10 B encoding sch em e is d ef ined at t h e FC- 1 lay er , w hich in t er t w ines t h e dat a char act er s w it h syn ch ron izat ion b it s. The secon d f unct ion of t he FC- 1 lay er is

m anagin g or der ed set s. Or der ed set s ar e uniq ue t r ansm ission w ord s t hat supp ort link syn ch r onizat ion an d con t r ol pr ot ocols. Fr am e delimit er s ar e an ex am ple of or der ed set s m anaged by t he FC- 1 layer . The t hir d f un ct ion of t he FC- 1 lay er is m anaging link - level pr ot ocols and st at es, su ch as act iv e, off lin e, lin k failur e, and link r ecover y. FC- 2 — The FC- 2 layer is r esponsible f or t he f un ct ion s associat ed w it h t he est ablishm ent of and com mu nicat ion b et ween t w o por t s. Th ese f unct ions in clud e por t log in, t h e exchan ge ( a com mu nicat ion const r uct t hr ough a Fib re Chann el SAN) and associat ed fr am e seq uences, • Table of Content s flow con t r ol, and err or d et ect ion and recov er y . Each of t hese t opics is cover ed lat er in m ore • I ndex det ail. The FC- 2 lay er also defin es t he Fibr e Chan nel fr am e f orm at s associat ed w it h all dat a I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion and cont r ol f r ames. By Cisco Systems, Inc.

FC- 3 — The FC- 3 ( Com m on Ser v ices) lay er is gener ally a placeh older for fut u r e adv anced ices, hich are com m on acr oss m ult iple p ort s of a nod e. Such FC- 3 com m on ser vices Pubser lishver: CiscowPress ( som e of w hich h ave b een im plem ent ed but ar e not heav ily u sed) include mu lt icast Pub Dat e: Sep tem ber 1 1, 2 003 ser v ices, com pr ession ser vices, and st ack ed conn ect ion r eq uest ser v ices. I SBN: 1- 58 705 -1 19 -2

Pages: 28 FC- 4 layer d ef ines how diff er ent pr ot ocols are map ped t o use Fibr e Ch annel. FC4 —11The Such upp er - lay er pr ot ocols inclu de SCSI - 3 , I P, v ir t u al int er face ( VI ) , and sever al ot h er s. Each of t hese pr ot ocols' com m ands, d at a, and st at us are m ap ped t o inf orm at ion un it s t hat ar e t hen carr ied b y Fib re Chan nel.

These layer can ion rou of ghly m apped t h eincomm on w OSI et wor k ing m p odel and cover ar e mage ean toft o The u pdat eds edit t heb eb est - sellingt oallone net ork ning r ef erence rov ides pr ov ide st r uct ur e t o t he p rot ocol for it s u nder st anding an d im plem en t at ion. essent ial an d cu t t ing- edg e t ech nologies. The f ollow in g sect ion ex plor es t he Fibr e Chan nel pr ot ocol in m or e det ail. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Fibre Channel Topologies New chapt er s include cov erag e of im por t ant

t opics like VoI P and EAP

A FibrCov e Ch annel consist of mologies ult iple lik conn ectical ion nt opolog includin sw it ched- f abr ic, erag e ofSAN cut tcan ing edge t echn e opt et wor kies, ing and st orgage ar bit r at ed- loop, an d point - t o- p oint . Each t op olog y dict at es associat ed Fibr e Chann el por t m odes t hat m usth ored b e supp ort ed Sy by st t he parwt icipat ices.in net w or king f or t he I n t er n et . Aut by Cisco ems, or ldwing ide dev leader I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Point-to-Point Topology t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Point - t o- p oint t opology is used pr im ar ily t o connect a host d irect ly t o a disk or t ap e dev ice. I t Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, off ers higher b andw idt h t h an a par allel SCSI im plement at ion, bu t is r est rict ed t o com m unicat ion and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all bet w een t w o devices. Poin t - t o- poin t t op olog y is giv ing w ay t o a m ore net w ork - or ien t ed t op ology , net w or kin g p rof essionals, r egar dless of ex pert ise. such t hat mor e d ev ices can be in t er conn ect ed as one lar ger net w or k or f abr ic. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Arbitrated-Loop a b r oad r ang e of intTopology egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag edeploy is alsoedext end edern ot o new n et wor s, but also o oldy.erAn , legacy A w idely y et old cononly necttion t opolog y isk ing t he concep ar b it r att edloop t optolog ar bit rat ed syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he realw or ld n et w or k ing en vir onm entper s inmwission hich loop is a logical loop con sist ing of up t o 126 Fibr e Ch annel d ev ices t h at ar bit r at e f or pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease t o t ran smit dat a. Th e loop is generally im plem en t ed using a Fibr e Chann el hub f or cab le pr odu ct iv itent y an imeby pr ovcreeat effin iciency, ing t het op r eader akedevices mor e in , cost - eff m anagem , tdh er g a st arhelp ph ysical olog y.mAll ont elligent t he loop shar e ticient he decisions for t h eir net w ork s. av ailab le loop b andw idt h . For exam ple, Fibr e Ch annel d isk d riv es ar e com m only ar r anged in sm aller ar bit r at ed loop s w it hin larg er disk su bsyst em s. The benef it of t he arb it rat ed loop is t hat it can int er con nect m ult iple d ev ices.

Private Loops

Older loop t opolog ies ar e g en er ally called pr ivat e- loop t opologies, b ecause t h e devices on t he loop und er st and only an 8- bit p riv at e logical ad dr ess of ot h er devices on t he local loop. Th is add ressin g schem e r est r ict s loop d ev ices fr om add ressin g devices on ot her loops. A m or e r ecent pu blic- loop im plement at ion sup por t s a f ull 2 4- bit hier archical ad dr ess, allow in g com m unicat ion bey ond t he local loop t o devices on ot her loops. Ther ef or e, usin g a pu blic- loop im plement at ion, m ult iple ar bit r at ed loop s can be int er con nect ed using a sw it ched fabr ic. •

Table of Content s

•

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Switched-Fabric Topology I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

The p r ef er r ed Fibr e Ch annel t opology t od ay is t he sw it ched- f abr ic t opology. I t off er s t h e best of bot h w or lds in t erm s of conn ect ion count s and available b andw idt h. The sw it ched- f abr ic t opology Pub lish er: Cisco Press r ep r esent s a cap abilit y sim ilar t o t hat of Et h er net / I P sw it ched n et wor k s. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: nel 1- 58sw 705it-1 -2 ar e ar r ang ed in a f abr ic and use a hier ar chical 24- bit Fibr e Ch annel I D Fibr e Chan ch19es ( FC_I D) Pages: t o rou 11 28t e fr am es ar ound t he fabr ic f rom sw it ch t o sw it ch. A Fib re Chann el fab ric m ay consist of a m ax imu m of 23 9 sw it ches, each w it h up t o p ot en t ially 64 KB por t s. Each por t on a Fibr e Chan nel sw it ch pr ov ides a d ed icat ed 1 Gbp s or 2 Gbp s of band w id t h t o each con nect ed dev ice. A sw it ched fab ric also consist s of a ser ies of d ist r ibu t ed serv ices, includ in g fabr ic- rou t ing ser v ices, nam e ser vices, an d secur it y ser v ices.

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Figur e 55 - 4 sh ows t hr ee of t he f our t op ologies. essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Figu r e 5 5 -4 . Fibr e Cha nn e l Topol ogie s New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Fibre Channel Port Types Fibr e Chan nel is a con nect ion - orient ed pr ot ocol in t hat nod es m u st est ab lish a chan nel v ia a login befor e com m unicat ing. Com mu nicat ion is est ablished bet w een logical elem ent s, ot herw ise k now n as por t s, ex ist in g w it h in p hy sical d ev ices. A por t can be on e of sev er al t yp es, d ep en ding • Table of Content s on t he t yp e of phy sical device and t h e con nect ion t op olog y. •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

Por t t y pes au t onegot iat e d ep en ding on w hat device or t op olog y t hey ar e dir ect ly con nect ed t o. By Cisco Systems, Inc.r est r ict t h e por t m odes t h at can be n eg ot iat ed . How ev er , y ou can ThePub f ollow g listPress d escr ibes all t he st an dar d and som e of t h e non st an dar d com m on por t t y pes lish er:inCisco t hat ar e used in Fibr e Chan nel SANs: Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 11— 28 The m ost b asic p ort t y pe is t h e N_Por t , or node p ort . All comm u nicat ion in a NPages: _ Port Fibr e Chan nel net w or k t ak es place bet w een N_Por t s or NL_Por t s. An N_Por t ex ist s in an end device t h at is conn ect ed t o a point - t o- point or sw it ch ed - fabr ic t op olog y. Mult iple N_Por t s can exist w it h in a sin gle phy sical device.

N L_ Por t — Node por t s t hat ar e w it h in end dev ices at t ached t o an ar bit r at ed loop ar e called The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of nod e- loop por t s or NL_Por t s. essent ial an d cu t t ing- edg e t ech nologies. F_ Por t — Wit hin a sw it ch ed f abr ic, sw it ch por t s t h at ar e connect ed d irect ly t o end d ev ices (Con N_Por called ic por oressen F_ Port s. t o n et wor k ing pr ofession als at all lev els, f rom ciset s) ovar erev iew s off abr t echn ologt sies t ial nov ice t o ex pert . FL_ P ort — Port s w it hin a fab r ic sw it ch t hat are con nect ed t o a pu blic ar bit r at ed loop ar e called fab ricpor t scov orerag FL_ ePort ant opics FL_Por t , pVoI ublic ar bitEAP r at ed loop s can b e New chapt er sloop include of s. imUsing por t ant like P and connect ed ov er a sw it ched- f abr ic t opology . FL_ Port s are con nect ed t o a loop of NL_Por t s. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age E_ P ort — When t w o Fibr e Chan nel sw it ch es ar e conn ect ed, t he r esu lt in g por t m ode becom es an pansion por t , w ororE_Por t . leader The result ingwlink f orm edt he betIw t w. o sw it ches is Aut h ored by ex Cisco Sy st ems, ldw ide in net or king f or n teen er n et called an I n t er- Sw it ch Link ( I SL) . E_ Port s are con nect ed only t o ot her E_Por t s. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat B_ P ort Theg br e por t , ort oB_un Por t , isand notan a dcom m on en port tcont m ode. A B_Por t er exnet t ends a ing Fib re enables net w— or kin p ridg ofessionals derst im plem em por ar y int w ork Ch annel I SL over a non Fibr e Chann el por t . B_Por t s conn ect only t o E_Por t s an d par t icipat t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing e in a nb asic of link Chan nel erolog s ov ies er Iin P ttoy pically use a env B_ Port indu stonly ry . Lear how set t o incor porser at evices. int er net w or kinext g tend echn a LAN/ WAN ir onm ent . int er face t o ex t end a Fibr e Ch annel I SL ov er t he I P n et wor k . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all TE_ —essionals, A special rpor t mdless ode of negot iat ed b et ween t w o Cisco MD S 90 00 m ult ilayer net w or kinPgort p rof egar ex pert ise. sw it ch es is a t r un king - ex pan sion por t , or TE_Por t . A TE_ Port is a su perset of an E_ Por t in t hat ecial m un echan ism su ppor s t h eand v ir t uWAN al SAN ilit y pof uilding Reader s waillsp obt ain taaggging reat er der st an ding of t LAN n etcapab w or k ing, ar bt icu lar ly nu t h emer ous abr ics onand t opser of vaices cominv m on phy fabrent ic. alTE_ Port s can inf b eorcon nect t o ot her har dwlogical ar e, prf ot ocols, olv ed . sical Fu ndam t ech nology mat ioned is only pr ov ided on TE_r Port a b r oad ang es. of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . TL_ePor t— A t rend anslat t , or nTL_Por conn ect s pt s, r ivbut at e also loop tsot oold p ublic loops or Cov erag is also ext ed iven ot loop only por t o new et wor kt ,ing concep er , legacy sw it ch ed f abr ics. A TL_Por t act s as an addr ess pr oxy for t h e pr iv at e dev ices on syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm enttshein w hich ar bit r at ed loop t r anslat f unct ionopt is im usef ul for older Fibrfor em Chance annel d ev ices t hat do pr of essionals oper at .e.ATools andiv eguloop id elines f or izing syst em per w ill incr ease not supp ort pu blic addr essing . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. GL_ P ort — A gener ic- loop por t , or GL_ Port , is not an act u al negot iat ed m ode, bu t r at h er r ef ers t o t h e por t 's cap abilit y. A por t t hat can n eg ot iat e an F_ Port , FL_Por t , an d E_Por t is called a GL_Por t . Figur e 55 - 5 illust r at es t he con nect ion m odes and possibilit ies.

Figu r e 5 5 -5 . Fibr e Cha nn e l Conn ect i on M ode s [ View full size im age]

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Fibre Channel Communication Model Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing

and st or age

h ored by Cisco Syect st ems, orhodology ldw ide leader in net w ort hking he aI nch t er n et . b et ween t w o Fibr e Aut Chan nel uses a conn ion mwet t hat requ ir es e setf or u p t of annel dev ices bef ore any exchan ge of dat a. How ev er, sev eral st eps mu st occur t o est ab lish a chan nel. IAft n t ern or k in gelTech book ,com Four h Ed ion ,bet is w a een comtpr er t et hewchann hasnologies b een estHand ab lished, m tun icatition w ehensive o en d d evrefer ices ence occur tshat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing accor d in g t o a hier ar chical m odel. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu fst ry . Lear n how por at int er net w ored kintgo t est echn in t ou nicat a LAN/ The ollow in g is a listt oofincor t he maj ore st eps r equir abolog lish ies comm ionWAN b et wenv eenir onm t w o ent . Comices pletusing e w it hdif new antdFibr u pdat edannel chaptt op er sologies. on secur it yer , st ical netewbeen or k in g, dev fer en e Ch Sev alormage, inor opt st ep s hav omscalabilit it t ed for y, and speed, simp licit y . t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. For point - t o- point : Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw St ar e, ocols, ser v ices ed .- tFu t ech inf or is prices ov ided e ppr1 ot . Dev icesand connect ed ininv a olv point o- ndam p oint ent conalfigur atnology ion behav e mat as t ion w o dev on aon a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions pr iv at e ar bit r at ed loop. Devices con nect ed poin t - t o- point m ust fir st per for m a loop t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . init ializat ion p r ocedu re ( LI P) t o det erm ine t hat t hey ar e in a point - t o- point config ur at ion Cov erag is also edr at n ot r ateher t h anext anend ar bit edonly loopt.o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals e. Tools and gu syst em. per for m ance w ill incr ease St e p 2 .oper On eatNL_Por t opens a idchelines annelf or t o opt t he im otizing her NL_ Port pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for3 .t hPor eir t net w ork St e p s can ex s. chang e dat a bet w een t hem selv es.

For ar bit r at ed loop: St e p 1 . Dev ices connect ed t o an ar bit r at ed loop m ust p er f orm a LI P t o acqu ir e an

Ar bit r at ed Loop Phy sical Add ress ( AL_ PA) , an 8- b it add ress used t o com m unicat e w it h ot her d ev ices on t h e net w or k. Dur ing t his p rocess, t he NL_ Por t det er min es wh et her an FL_Por t is pr esent on t he loop, mak ing it a pu blic loop. I f no FL_Por t is pr esent , t he loop is a p r iv at e loop . St e p 2 . On e NL_Por t arb it rat es f or access t o t he loop t o com m un icat e w it h anot her NL_ Port . • •

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St e p 3 . Aft er ar b it rat ion has been w on, t he NL_ Port opens a connect ion t o t h e ot her I ndex NL_ Port ( or FL_ Port if comm un icat in g w it h a device on t he sw it ched f abr ic) .

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By CiscoSt Systems, Inc.t s e p 4 . Por

can ex chang e dat a bet w een t hem selv es.

Pub lish er: Cisco Press

For Pub sw itDat che:edSepfab ic: 1 1, temr ber

2 003

I SBN: 1- 58 705 -1 19 -2

St e p 1 . Dev ices connect ed t o t he sw it ched fabr ic m ust perf or m a f abr ic login pr oced ur e ( FLOGI ) t o acq uire a Fibr e Chan nel add r ess ( FC_I D) , a 2 4- bit addr ess used t o com mu nicat e w it h ot her devices on t he sw it ched n et wor k .

Pages: 11 28

St e p 2 . On e N_Por t m ust log in t o t he ot h er N_Por t or NL_Por t it w ill com m un icat e wit h . I t per for m s a p or t login pr oced ur e ( PLOGI ) t o est ab lish a chan nel w it h t he t ar get ed device. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essentSt ialean p 3d . cu Por t t ingt s can edgex e chang t ech nologies. e dat a bet w een t hem selv es. Conas cise ov erm v iew s ofion t echn olog ies essen n et wor kbing ofession alsices, at all f rom As soon a com unicat ch annel h as beent ial estt o ablished et w pr een t w o dev Fiblev r eels, Chan nel nov ice t o ex pert . follow s a st rict com m unicat ion m odel t hat consist s of a hier archy of dat a st r uct u res. At t he t op of t he hier ar chy is t h e ex chan ge. A Fibr e Ch annel ex ch ange is t yp ically m apped t o an u pper - layer Newcom chapt er s su include erag- e t ant t opics likeexVoI P and EAP pr ot ocol m and ch as cov a SCSI 3 of re aim d por com m and. Each chang e con sist s of a ser ies of un id irect ional sequences. Each sequ en ce con sist s of a ser ies of num ber ed f ram es t h at t r av el eragt oe dest of cut ing edge ologiesges lik emopt n eten wor k ing andt wst age fr om Cov sou rce intat ion. Multt echn iple exchan ay ical be op bet w een o or devices, each w it h it s ow n set of orig in at or exchan ge I Ds ( OX_I Ds) an d r espond er ex chang e I D s ( RX_ I D s) . Figur e 55 Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . 6 illust r at es t his h ier ar ch ical relat ionship and pr ov ides a sim ple SCSI - 3 exchan ge exam p le. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing 5 5 -6por . Fibr e erCha e lgSCSI Ex cha Ex aWAN m ple indu st ry . Lear Figu n howr teo incor at e int net wnn or kin t echn olog ies inng t o ae LAN/ env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all [ View full size im age] net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Fibre Channel Addressing Fibr e Chan nel has t w o t y pes of add resses t h at ar e u sed t o id en t ify a device or sw it ch p ort . The fir st is a globally u nique assigned add ress called t he w or ldw ide n am e ( WWN) . The WWN is assig ned b y t he m an ufact u rer an d is g uar ant eed t o be g lobally uniq ue. This concept is ver y similar t o t he MAC ad dr ess in an Et h er net device. •The second t Table of add Content y pe of resss used in Fibr e Chan nel is a dy nam ically assig ned hier ar chical addr ess •t hat let s fr amI ndex es be int elligent ly r out ed fr om on e dev ice t o anot h er . Th is addr ess is called t he IFibr nt e rn w or knel ing Te Edit ion e et Chan I Dchnologie ( FC_I D)s .HIanndbook a Fibr, Four e Chthannel n et w or k , t he FC_I D is m app ed t o t he W WN such tBy hat init iat or s can use t he W WN t o con t act a device, and it w ill b e t r anslat ed t o an FC_ I D f or Cisco Systems, Inc. com mu nicat ion . lish er: Cisco Press ThePub FC_ I D ad dr esses assign ed t o devices depend on t he t y pe of t opology : Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Point t oPages: -11 28 p oi nt — Poin t - t o- poin t conn ect ions ar e act u ally im plem en t ed as a pr iv at e loop w it h t w o dev ices. Becau se t he d ev ices ar e in a p riv at e loop, t hey use only an 8 - bit AL_PA. The ad dr ess is in t h e r ange of 0 x0 000 01h t o 0x 000 0EFh. Ar bit r a t ed loop — Arb it rat ed loops can be im plem en t ed as p riv at e or public loop s t hat det er min e t he t y pe of addr esses assig ned. I n a pr iv at e- loop t op ology , a st and ar d AL_PA is The uassig pdat ed of ilar t he fashion b est - selling all- innet wt opolog ork ing y. r efEach erence rov ides of is nededit in ion a sim t o a poin t - tone o- point d evp ice on a cover pr iv atage e loop essentassig ial an d cu t t ingedg e t ech nologies. ned an ad dr ess in t he r an ge of 0x 00 000 1h t o 0 x0 000 EFh ( h ow ev er only 1 26 devices m ay exist in a given ar bit r at ed loop) . Con ov er v iew s of t echn essen o ore n et wor k ingt sprt hat ofession alsg at at eway all lev Publcise ic l oop— A pu blic loopolog conies t ains onet ial or tm FL_Por act as s els, t o a f rom nov ice t o ex pert . sw it ch ed f abr ic. As su ch , t he addr esses assig ned t o dev ices on a p ublic loop cont ain a f ull 24 - bit ad dr ess. Th e fir st oct et is t h e Dom ain_I D t hat is assig ned t o t he sw it ch. Th e second New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP oct et ident if ies t he par t icular loop on t he sw it ch. The t hir d oct et is used f or t he AL_PA assig nedet of o t cut he tdevices t he loop. The t alway s hkas AL_PA of 0x 00h . Ther ef or e, Cov erag ing edgeont echn ologies likFL_Por e opt ical n et wor inganand st or age t he valid FC_I D addr ess ran ge f or devices on a p ublic ar bit r at ed loop ar e 0x dd llaa, w her e dd t he Dom ain_ ISy D st ofems, t h e at ached swleader it ch in in t h enet r ange of 0 fx0 Autis h ored by Cisco wtor ldw ide w or king or1h t het oI n0 txEFh er n et(. 1 t o 239 ) , ll is t he loop ident if ier in t h e r ange of 0 x0 0h t o 0 xFF, and aa is t he AL_ PA in t he r an ge of 0x 01 h 0xor EFh, her enologies 0x 00 h isHand r eserbook v ed ,f or t he I n t ernt oet w k in gwTech Four t h FL_Por Ed it iont ., is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Sw i t ch ed fa br ed cep - fabt ric dr ess is b ased FC_I Ds t h at se t he 24ing - bit t echnologies. Mast er ic— t he tAersw m it s,chcon s, tad echn ologies, an d on devices used in ut oday ' s ent netirweork add ress. Each sw it ch w it hin a sw it ch ed f abr ic is assign ed one or m ore Dom ain _I Ds. This indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Dom D cananbe of as er a rou pr efix t hat t h e sw ch uses o kr out fr am es t y, o Com plet e ain_ w it h I new d ut hou pdatght ed chapt s ont ing secur it y , st or age, optitical net wtor in g,e scalabilit dev ices connect ed t o ot h er sw it ches. The f irst oct et of a sw it ch ed fab ric FC_ I D is t h e and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Dom ain_ I Dessionals, . I t is in t he r andless ge ofof 0xex 01pert h t oise. 0x EFh. The secon d an d t hird oct et s of a sw it ched net w or kin g p rof r egar fab r ic FC_I D ar e called t h e Area_I D and Por t _I D, respect iv ely. These com pon en t s of t he FC_I ust b ea locally ique ch. How eyw or ar ke ing, u sedp ar in t dicu ifflar er ent Reader s wDill m obt ain g reat erunun der on st aneach dingsw of itLAN and ever WAN, tnhet ly t hweays b y t sw it ch vand endor o ident ify ed en.d-Fu fab r ic devices. Som e v endor allocat e tpr hese har dwdif arfer e, en pr ot ocols, sersv tices inv olv ndam ent al t ech nology inf orsmat ion is ov ided on comr ang ponent b ased sicalserv p ort t o wh ich ing an end device is conn ects,ed. herquest v en dor a b r oad e ofs int egr alon sy tsthe emp shyand ices, in clud det ailed descr ipt ion revOt iew ionss allocat e cept t hesecomp on ar eh fir st f ir st - ser st andr ard ot fu d ict at e st any t o en su re con en- come, sion and r et en tved ion, basis. and adThe dit ional esoudoes r ces nf or rt her udyr ules . for ehow t hese dred essncom ponten t s m ust b e allocat ed. Howev er ,also t he tvoalid e for t hese Cov erag is also extad end ot only o new n et wor k ing concep t s, but old rerang , legacy com s gis a0x t o 0 ic xFFFFh. syst em s, ponent pr ovid in m0000 or e rhealist pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Table 5 51 ysuan mm ar pr izes if fer en t help FC_ ing ID m odels and m t hake eir ad dreessing r anges and lim it s. pr odu ct iv it d im ov et he effdiciency, t he r eader mor in t elligent , cost - eff icient decisions for t h eir net w ork s.

Tab le 5 5 - 1 . FC_ I D M odel s an d Lim i t s

8 bi t s

8 bi t s

8 bi t s

Sw it ch t op ology m odel

Dom ain ( 01- EF)

Ar ea ( 00 - FF)

Dev ice ( 0 0- FF)

Pr ivat e- loop device ad dr ess m odel

00

00

Ar bit r at ed loop Phy sical addr ess

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Pub device add r ess odel , Four th Edit Dom I nt e rnlicet wloop or k ing Te chnologie s H am ndbook ionain

( AL_ PA) ( 0 1- EF) ( 01- EF)

Ar ea ( 00 - FF)

By Cisco Systems, Inc.

Ar bit r at ed loop Phy sical addr ess ( AL_ PA) ( 0 0- EF)

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 11 28 FibrePages: Channel Frame Format

A Fibr e Ch annel f r ame has t h e st andar d st ru ct ur e show n in Figur e 55 - 7. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu r e 5 5 -7 . Fibr e Cha nn e l Fr a m e For m at

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com A Fibr plet e Ch ew annel it h new f r ame an dcan u pdat r ang ede chapt in size er sf rom on secur 36 byittyes , st t oor2age, 148 opt by t ical es, depend net w or kining g, onscalabilit t h e am ount y, anddat of speed, a pay load. t h is book Th e follow is a com ingplet is ae dan escr d uipp-t ion t o- dof attehe r efmerajor encecom t o pon t he en t opt sics of t a hat Fibr are e Ch essen annel t ial t o all net fr am w e: or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e D LEs— D LEs ar e user sedv ices for sy nchr and or tdech alig nm en tinf b or et ween smov it tided er anon d har dwI ar e, pr otIocols, and inv olvonizat ed . Fuion ndam entwal nology mat iont ran is pr r eceiver DLEs indicat h esr ead ess ices, t o t r ansm anddet arailed e const antipt ly ion t rans,sm it tiew ed w hen ions no a b r oad r ang e. Iof int egr al sy est tem and inserv in cluditing descr rev quest ot her d atcept a is comp p resen t ed o senand d. An DLE is act a ional 4- by treesou or der ed fset is st t ran t o en su re con r eh entsion r et Ien t ion, andually ad dit r ces or fut hat rt her udysm . it t ed fr om dev ice t oed anot h er . Accor dingn tet o wor t hekFibr Chan nel st and ardts, ev ery t r ansmit t ed Cov erag e isone also ext end n ot only t o new ing econcep t s, but also o old er , legacy fr am e ovid m ustin hav er edicset s,ur wehich oft en inclu edvir aftonm er went ards. in Each syst em s, pr g a emsix or eord r ealist pict of t he realw orde ld InDLEs, et w orinser k ing ten w hich r eceived oper fr amat e e. m Tools ust b eand spaced y a mfinim umimof t w o syst or dered setfor s.m ance w ill incr ease pr of essionals gu idbelines or opt izing em per pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient SOF— ar t wofork Frs. am e is a 4 - by t e or der ed set t hat im m ediat ely pr ecedes t he fr am e decisions for The t h eirStnet cont ent . The SOF also in dicat es t he class of t he Fibr e Chan nel f ram e t o be r eceiv ed . Fra m e hea de r— The f ram e h ead er is a 24 - by t e header consist ing of mu lt iple cont r ol f ields. The f r am e header includes f ields su ch as t h e sour ce FC_I D, dest inat ion FC_I D, ex change I Ds, r out ing cont r ol, an d sever al ot h er par amet er s. The t ot al st ru ct u r e of t he Fibr e Ch annel header is show n in Figur e 55 - 8.

Figu r e 5 5 -8 . Fibr e Cha nn e l Fr a m e He ade r For m at

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

D a t a fi el d— The dat a field con sist s of t h e act ual u pper - layer p rot ocol d at a. I t can r ange fr om 0 t o 21 12 by t es. CRC— The Cy clical Red und ancy Ch eck is a 4- by t e f ield used t o v er ify t he f ram e's int egr it y. The CRC is only calcu lat ed u sing t h e fr am e header an d t h e Dat a field. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. EOF— The En d of Fr am e is a 4 - by t e or der ed set t h at im m ed iat ely p reced es t he f ram e cont ent . The EOF also indicat es t he class of t he Fibr e Channel f r am e. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The f ollow in g is a br ief descr ipt ion of each field in t h e Fib re Chann el header: nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP R_ CTL— Rout ing Cont r ol ( 1 by t e) cont ain s t w o 4 - bit su bfields, r out ing t y pe, an d inf orm at ion. Rout in g b it s dif ferent iat e fr am es based on fu nct ion or ser v ice, such as dat a Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age fr am es v er sus link cont rol fr am es con t aining comm an ds or st at u s. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . D _ I D — Fibr e Chann el dest in at ion Fibr e Ch annel I D ( FC_I D) ( 3 by t es) . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat CS_ CTL— Class- Sp ecific Cont r ol ( 1 by t e) is u sed only in Class 1 or Class 4. The Fibr e enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Ch annel classes ar e discussed in mor e d et ail in t h e next sect ion. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . S_ I D— Fibr e Chann el sou rce FC_ I D ( 3 by t es) . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t hThe is book com d uicat p- tes o- dt hateeupp r ef er heocol t op ics hat in aret he essen t ial Ty pe — Ty peis faield ( 1plet by tee)anind er ence - levelt op rtot car rt ied f r am e t o all net w or kin g p rof essionals, r egar dless of ex pert ise. pay load. Reader w ill obt reat er un an con dingt ains of LAN andb er WAN et w or p ar ly t hof e t he F_sCTL— Frain am ae gCon t rol ( 3 der by tst es) a num of fnlags t h kating, cont r olt icu t helarf low har dwseq ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on uence. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con comp r eh en sion and r et(en dit ional esouar ces f orsequ fu rt her udy SEQ_ I Dcept — The Sequence I dent if ier 1 bt ion, yt e) and uniqad uely id en t rifies g iven en cestwit h .in t he Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy cont ex t of an exchan ge. Each fr am e is ident if ied w it hin an ex chang e by a SEQ_I D. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper atae.Field ToolsCont andr ol gu(id or opt im izing syst em per for m anceheaders w ill incrat ease D F_ CTL— Dat 1 elines by t e) fspecifies t he p resence of opt ional the pr odubeginn ct iv it y ing an dofimt he pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost eff icient D at a f ield for Dev ice_ Dat a or Video_Dat a fr am es. D F_ CTL bit s ar e n ot decisions t hul eironnet w k_ orkCont s. r ol or Basic Link Ser vice fr am es. m eanfor ingf Lin SEQ_ CN T— Seq uence Coun t ( 2 by t es) ident if ies t he or der of t h e t r ansmission of f r ames w it hin a sequence. I t is u sed by a seq uence r ecipient t o account for all t r ansmit t ed fr am es. OX _ I D — Or ig inat or Exchan ge I D ( 2 b yt es) id en t ifies an indiv idual ex chang e. Th is ident it y

is set by t he or iginat or of t he exch ange. RX _ I D — Resp onder Ex chan ge I D ( 2 b yt es) id en t ifies an in div id ual ex ch ange. Th is ident it y is set by t he r esp onder t o t he ex ch ange. P ar am e t er s— The Par am et er s f ield ( 4 by t es) is dependent on t he specific f ram e t y pe, as ident if ied in t he R_ CTL field. •

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Fibre Classes of ,Service I nt e rn et wChannel or k ing Te chnologie s H a ndbook Four th Edit ion By Cisco Systems, Inc.

Fibr e Chan nel defin es sev er al classes of serv ice, alt hough in pr act ice only t w o classes ar e pr edom inant ly u sed . Each class of ser v ice is diff er ent iat ed by it s u se of ack now ledgm ent , flow Pub lish er: Cisco Press cont r ol, and chan nel r eserv at ion: Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Class Pages: 1 11is 28 a conn ect ion- or ient ed ser v ice w it h confir m at ion of deliv ery or not ificat ion of non deliv ery . A chann el mu st be est ablished f r om sour ce t o d est inat ion bef ore t he connect ion is gr ant ed. Class 2 is a conn ect ionless ser v ice b et ween por t s w it h con fir m at ion of d eliv er y or not if icat ion of non deliv ery . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essentClass ial an3d iscuat tconn ing- edg e t ech nologies. ect ionless ser v ice b et ween por t s w it h no conf ir mat ion of deliver y or not if icat ion of non deliv ery . Th is is t he m ost wid ely u sed class of serv ice in p r act ice t od ay. Con cise ovaerconn v iewect s of t echn olog n etides wor kaing ofession all lev Class 4 is ionor ient edies seressen v ice tt hial att o p rov vir pr t ual cir cuitals b etat ween N_els, Por ft rom s w it h nov ice t o ex pert . conf ir m at ion of deliv ery or not if icat ion of non deliv ery an d guar ant eed band wid t h. New s ult include eragof e of im por t opicsonlike VoI EAP Classchapt 6 is aerm icast vcov ar iant Class 1 pt ant rov iding e- t omPanand y ser v ice w it h confir m at ion of deliver y or n ot if icat ion of n ondeliver y. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Table 5 5- 2 p r ovides an ov er v iew of t he char act erist ics of each class of ser vice. I n SANs t oday , Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Class 3 is t he m ost wid ely u sed. Most f abr ics also su ppor t Class 2. Any ot her class is not com mon ly used t od ay. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Tab le 5 5 - 2 . Fi br e Ch an ne l Cl ass of Ser v ice and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. At t r ib ut e Cla ss 1 Cla ss 2 Cla ss 3 Cla ss 4 Cla ss 6 Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Con nect ionpr- orient ed and ser v ices inv olv edYes Noal t ech nology No inf or mat Yes har dw ar e, ot ocols, . Fu ndam ent ion is pr ovYes ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Band wid t h reser v ed 10 0% No No Fract ional 10 0% t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new Yes n et wor k ingNoconcep t s, No but also t o Yes old er , legacy Gu aran t eed lat ency ( QoS) Yes syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich t eed deliver der and gu id elinesYes No syst emNoper for m ance Yes w ill incr ease Yes prGu ofaran essionals oper atye.orTools f or opt im izing prDeliver odu ct iv y an dmim pr ov e eff iciency, help ing t he r eader m ake morNo e in t elligent , cost - eff icient y itconfir at ion—ACK Yes Yes Yes Yes decisions for t h eir net w ork s. Fram e m u lt ip lex ing w it h p or t s No Yes Yes No No En d- t o- end f low con t r ol

Yes

Yes

No

Yes

Yes

Lin k- level f low cont r ol

SOFc1

Yes

Yes

Yes

SOFc1

Fibre Channel Fabric Routing I n a sw it ch ed - fab ric t op ology , a d yn amic rou t ing pr ot ocol is used t o r out e f r ames t h r ough t he connect ed f abr ic. This r out ing p rot ocol is called Fabr ic Sh ort est Pat h Fir st ( FSPF) . FSPF is loosely based on a subset of t h e I P r out ing p rot ocol Open Sh or t est Pat h Fir st ( OSPF) . •FSPF is a linkTable Content s t hat r equ ir es all sw it ch es t o ex ch ange link - st at e in for m at ion, - st atof ep rot ocol •includin g t h eI ndex oper at ional st at e an d rou t ing met r ic f or each dir ect I SL. Usin g t his inf orm at ion Ist ntor e rn w orak ing Te chnologie s H each a ndbook th Edit edet in local dat abase, sw,itFour ch per forion m s t he w ell- kn ow n D yk st r a algor it hm t o com put e t heCisco sh ort est patInc. h t o ev er y ot h er Dom ain_I D. By Systems, I n t he case w here mu lt ip le eq ual- cost pat hs t o t he sam e dom ain ex ist , a load - balancing fu nct ion Pub lish er: Cisco Press is per for m ed b et w een t he pat hs. Should chang es t o link - st at e st at us occur , such as a mod ified Pub Dat e: Sep tem ber 1 1, 2 003 m et ric or failed link , link - st at e up dat es ( LSUs) ar e ad ver t ised, and r out es ar e r ecom put ed based 1- 58 705 -1 on t he InSBN: ew ly acqu ir 19 ed-2infor m at ion. By t unin g link m et r ics, y ou can eng ineer t raf fic f low s and Pages: 28 in a Fibr e Chann el net w ork . r ecov ery p at11hs

Fibre Channel Flow Control The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of On e of t he m ost ef fect iv e m ech anisms w it h in Fibr e Ch annel is t he f low - cont rol cap abilit y. Fibr e essent ial an d cu t t ing- edg e t ech nologies. Ch annel f low cont r ol is b ased on a per m ission sy st em w hereby a dev ice or por t cann ot t r ansm it a f r am e unless it h as a cr ed it . Fib r e Chan nel has t wo flow - cont r ol m echanism s—end- t o- en d an d bu ff erCon - t o-cise b uff er. ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . En d- t o- end f low con t r ol is used t o pace t r af fic b et w een t w o end devices and is not used v ery oft en .New Buf fer - t o-er buf fer f low cov cont r ol e t ak bettwopics een ev er yVoI adj p air of por t s along any chapt s include erag ofes implace por t ant like P acen and tEAP giv en p at h in a Fib re Chann el net w ork or bet w een t w o d ev ices on an ar bit r at ed loop . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Buf fer cr ed it s r elat e t o t he n um ber of inpu t b uff ers t hat ex ist on t he ad jacent con nect ed por t . Du ring a hfab ric by logCisco in pr ocedur e, t he of b uff er edit s king av ailable t o Iadjacent Aut ored Sy st ems, w ornum ldw ber ide leader in cr net w or f or t he n t er n et . devices is exchan ged. Bu ff er cr edit s ar e r ep len ish ed t o t he n eigh bor ing device w hen an in put bu ff er is I n t ern emp t ied et w . When or k in gan Tech inpu nologies t bu ff erHand is em book p t ied, , Four a dtev h ice Ed itgenerat ion , is aescom a 4-prbehensive yt e R_RDrefer Y com ence mant hat d and enables sen ds it net t o tw h or e neighb kin g p rorin ofessionals g d ev ice,t ot hereby un derstreplenishing and an d im plem t h e en cr edit t cont . em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Buf bu ff er f low tcont r ol por b ecom es er increasingly por t olog ant as istt oanaceLAN/ is inWAN t r oduced et ween indufer st -ryt o. Lear n how o incor at e int net w or kin gim t echn iesdin env ir bonm ent . adj acen t por t s. As d ist an ce increases, t ran sit delay or lat ency also incr eases. The add ed lat ency Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, incr t imbook e r equ t oplet r eceiv R_RD f r ence om t he e ics end. I f nare ot enou and eases speed,t he t h is is ira ed com e ane dan u pt o- d Y atback e r ef er t o rt em he ot t op t hat essengh t ialcrtedit o alls ar e av ailab le, n eig hbor ing dev ices m ight not be ab le t o sust ain w ir er at e use of t h e lin k bet w een net w or kin g p rof essionals, r egar dless of ex pert ise. t hem b ecause of t h e t hr ot t ling nat ur e of buf fer cr ed it s. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e This scen io ot isocols, t he basis plan ning w hen exalt end g a Fib inf r e or Chan oss an har dw ar e,arpr and of serav ices inv olvex eder. cise Fu ndam ent t echinnology matnel ion SAN is pr acr ov ided on opt SONET/ SDH w ork t h e serv pu rpices, oses in ofclud r emot datailed a replicat fors,d rev isast er quest r ecov ions er y . a b rical oadorr ang e of int egrnet al sy st emfor s and ing edet descrion ipt ion iew The u lereofcon t hum is t hatr eh one BB_ Cr ed it y 2 krm of rdist su st st ain 1 .Gbp s t o enr su ceptb comp en sion and r etisenr equir t ion, ed andf oradever dit ional esou cesance f or fut ort her udy of ilizateion. For ext ex am o sust 1 - Gbp linkeing r at e ov er an k merlink , 50 cr ed it s Covuterag is also endple, ed nt ot onlyain t o anew n et swor concep t s, op butt ical also100 t o old , legacy m ustem b es, supp ortin edg on en d. icAnpict y addit ional en cy hr ough ions syst pr ovid a meit orheerr ealist ur e of t he lat realw orinldt r oduced n et w or kting en viract onm entsuch s in was hich pr ot ocol conv ersion, pr ession, encry pt ionopt f urim t her incr eases t he for need f or m oreincr bufease fer of essionals oper at e.com Tools and guor id elines f or izing syst em per m ance w ill credit pr odus. ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Figur e 55 - 9 sh ows t he Fibr e Ch annel b uff er - t o- buf fer f low - cont r ol mod el as it r elat es t o com mu nicat ion b et w een a host and a disk in a f abr ic.

Figu r e 5 5 -9 . Fibr e Cha nn e l B uf f er - t o- Buf f er Fl ow Con t r ol [ View full size im age]

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Fibre Channel Distributed Con cise ov er v iew s of t echn ologFabric ies essenServices t ial t o n et wor k ing

pr ofession als at all lev els, f rom nov ice t o ex pert . A Fibr e Ch annel sw it ched fabr ic pr ov ides a ser ies of d ist r ibut ed ser v ices t h at aid in t he New ent chapt er sigur include erag e ofitim porat ant like and EAP m anagem , conf at ion,cov and secur y of Fibr teopics Chann el VoI fabrPic. Som e of t he m or e com mon ser v ices ar e d escrib ed in t his sect ion . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

Directory Services

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables netannel w or kin g picr ofessionals derst an dory imser plem en of t cont por ar erenet w ork A Fibr e Ch f abr supp ort s a tdoistun r ibu t edand dir ect vice t en em called t hey int nam serv er .ing t echnologies. Mast t heressin t er mgs,assigned con cep t s,in taechn an dfab devices used ' s ect netory w ork ing Becau se t he FC_I Deradd Fib ologies, r e Chan nel ric is dy naminic,t oday t he dir indu st ryhelp . Lear n ap howa dev t o incor atice WWN int er net t echnFC_ ologIies in t o a aLAN/ env ir onm ser v ice sm ice'spor st at t o witor s kin r outgeable D . When d evWAN ice log s in t o t hent e . Com plet w itom h new an dregist u pdaters ed itchapt , st or weorof k initg, scalabilit fab r ic, it eaut at ically self weritsh on t hesecur namiteyserv erage, alonopt g wical it h net som s at t r ibut es.y, and speed, t hion is book a com e anby d uany p- t o-en d at r efices er ence t o t he op ics t hat t ial t o all This in for m at can tis hen be qplet ueried d de ev t o locat e at specific d evare ice essen or dev ices net g pcapab rof essionals, w it hw or spkin ecific ilit ies. r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Zone Services a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . To r ovide d egend reeed of nsecu rit y twoitnew h in an et Fibwor re kChann el fabtric, zone sert vices r est r ict Covperag e issom alsoe ext ot only ing concep s, but also o old er , legacy com mus, nicat ion b ed icd ev ices. Chann logical gronm oup ent ing sofindevices syst em pr ovid inet g waeen m orat e trach ealist pict ur e A of Fibr t heerealw orelldzone n et wis orak ing en vir w hich tpr hat ar e per m oper it t ed at t oe.com m un icatgu e.idBecause t hese dev icessyst m ay at for t ach to w diff of essionals Tools and elines f or opt im izing embeper med ance illerent incr ease sw it chct es, zoning at ion is help dist ring ib utt he ed rbet w een all sw it ch t he fabr ic. - eff icient pr odu iv itt hy ean d im prconf ov e igur eff iciency, eader m ake mor e es in tin elligent , cost decisions for t h eir net w ork s. Zones can be bu ilt using a var iet y of ident ifier s, in clu ding FC_I Ds, p hy sical sw it ch p ort index es, or t h e m ost comm on WWN. There ar e t w o zone enf or cem en t m et hod s—har d zoning an d soft zoning. Har d zoning inv olves f ilt er ing fr am es in har dw ar e t o enf or ce t he zonin g conf igur at ion. I t is t he most secur e im plement at ion . Sof t zonin g sim ply inv olves f ilt er ing dir ect or y ser vice inqu iries t o allow only cer t ain dev ices t o be v isib le. Sof t zon ing is not fu lly secu r e, becau se an end device m ust kn ow anot h er en d d ev ice' s FC_I D t o b yp ass t he zon e and comm u nicat e w it h t he

end device.

Management Services Anot h er ver y useful dist r ib ut ed ser vice, based on t h e ANSI T11 Gener ic Ser v ices St an dar d ( FCGS and FC- GS- 3) , is t he d ist r ibu t ed m anag em ent ser v ice. I t let s d ev ice at t r ibut es an d •conf ig ur at ionTable in forofmContent at ion bs e r et rieved w it hin t he f abr ic. This inf or mat ion m ay include su ch •at t r ibut es as I sof ndex t w ar e ver sion , har dw ar e v ersions, d ev ice cap abilit ies, logical d ev ice nam es, an d Idev nt e rn w or Te chnologie s Ha ndbook ,I Four th it Edit iceet m ank ing agement I P add r esses. n add ionion , inf orm at ion can b e gat h er ed about connect ed por t s an d neig hbor devices. Alt h ough t h is in for m at ion is ver y useful for m an agement pu rp oses, By Cisco Systems, Inc. m any v endor s h ave b een slow t o ad opt t he capab ilit y . How ever , m or e and m ore vend ors are plann ing su ppor t for t he nex t r ev ision, nam ed FC- GS- 4 , w hich will let ev en m or e conf igur at ion Pub lish er: Cisco Press inf orm at ion be r et r iev ed f r om t he fabr ic. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 11 28 StatePages: Change Notification Services

I n most t r adit ional d at a n et w or k s, infor m at ion about fau lt s in t he net w or k w as r elay ed t o ot h er net w or k elem ent s, such as swit ches an d r out er s. How ever , Fib r e Chan nel ext end s t his ser vice t o end devices. Using t he St at e Ch ange Not if icat ion Serv ice and, m ore r ecen t ly, t he Regist er ed The ed eedit of ion t he( bRSCN) est - selling all- inone net w ork ingregist r ef erence p rov ides of St at eu pdat Chang Notion ificat Ser v ice, end dev ices can er t o receiv e notcover if icatage ion of essent ial an d cu t t ingedg e t ech nologies. event s in t h e fab ric. Wh en ev en t s occu r in t he net w or k , eit her accident ally or in t ent ionally, RSCNs are generat ed t o not ify ot her devices of t he ev ent occur r en ce. Using t he RSCN f acilit y , dev ices can react m u ch m or e quick ly t o f ailu re ev ent s r at h er t han w ait in g f or t im ers t o ex pire. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

The iSCSI Protocol The iSCSI pr ot ocol enables a SAN solu t ion w h er eby SCSI is t r anspor t ed ov er t he t op of TCP/ I P. iSCSI can lev erag e any I P- capab le t ran spor t , bu t is p rim ar ily t arg et ed t ow ar d Et her net - based SANs. Using iSCSI , SAN design er s can bu ild m or e cost - ef fect iv e SANs, esp ecially for t he •connect ion ofTable Content m idrofan ge sersv ers an d st or ag e. •

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

iSCSI Communication Model By Cisco Systems, Inc.

Pub lish er: TCP/ Cisco Press iSCSI u ses I P t o est ablish sessions sim ilar t o t hat of Fibr e Chann el. How ever , u nlike Fibr e Pub Dat e: Sep ber 1 1,do 2 003 Ch annel, iSCSItem n odes not need t o log in t o t he Et hern et fab ric t o est ablish com mu nicat ion. I SBN: 158 705 -1 19 -2 Sessions ar e est ablished b et ween iSCSI init iat or s ( host s) an d iSCSI t ar get s and m ay consist of m ult iple TCP/ I P connect ions. How ev er, any g iv en SCSI exchan ge ( com m and) m ust b e con duct ed Pages: 11 28 on one TCP connect ion. I SCSI uses t he w ell- k now n TCP por t num ber TCP/ 326 0 f or all iSCSI connect ions. An iSCSI t ar get can be eit h er an iSCSI / Fibr e Chan nel gat ew ay or an act ual iSCSI enabled disk or t ape arr ay .

Figur e 55 - 10 illust r at es t he iSCSI comm un icat ion m odel. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Figu 5 5olog -1 0ies . iSCSI Com mwor u nik ing catpr ion M ode Con cise ov er v iew s ofrteechn essen t ial t o n et ofession alsl at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Befor e t r ansm it t ing any SCSI com m and s, an iSCSI init iat or m ust log in t o an iSCSI t arg et . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Du ring t h is login phase, t he iSCSI t ar get s ar e discov er ed and ar e m app ed t o block devices w it hin har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on t he host . Figur e 55 - 11 illust r at es t he log in p rocedur e. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Figu r e 5 5 -1 1 . iSCSI Logi n Pr oce du r e pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. [ View full size im age]

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

iSCSI Frame Format The u pdat ed edit ion of t he b est - selling

all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. iSCSI u ses TCP for it s t r anspor t . How ever , a sp ecific iSCSI header is used f or session con t r ol. Figur e 55 - 12 ou t lines t he iSCSI header and it s v ar iou s com ponent s. Th e follow ing list pr ov id es Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom t he det ails. nov ice t o ex pert . New chapt s include e of por like VoI PPDU andt he EAP Opcode — er The Op cod ecov ( 1erag by t e) indim icat est ant t h et opics t y pe of iSCSI header encapsulat es. Ther e ar e t w o t y pes of op cod es: in it iat or and t ar get . I nit iat or opcodes ar e in PD Us sent by Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age t he in it iat ors ( requ est PDUs) , and t ar get op cod es are in PDUs sent b y t he t arg et ( r esp onse PDUs) . An iSCSI login and a SCSI comm and ar e t w o diff er ent ex am ples of opcodes. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Opcode - spe cif ic f ie ld s— This field ( 3 b yt es) has dif fer en t m eaning s dependin g on t h e I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat t y pe of op cod e. For ex am ple, an iSCSI login opcode uses t h is area t o st or e iSCSI v er sion enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing nu mb er s an d log in cont r ol flags. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . AH S Le n— This is t he t ot al lengt h of all ad dit ional h ead er segm ent s ( AHS) in 4- by t e w or ds, Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, includin g p adding , if any . The Tot alAHSLen gt h ( 1 by t e) is u sed only in PDUs t hat hav e an and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all AHS. I t is 0 in all ot h er PD Us. net w or kin g p rof essionals, r egar dless of ex pert ise. D a t a fi el d le ngt h — This is t he dat a segm ent pay load lengt h in by t es ( exclud in g padd in g) . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e The D at aSeg m en t Lengt h ( 3 b yt es) is 0 w henev er t he PDU has no dat a segm ent . har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang ofcod int egr al ecif sy stic em s ld and ices,opcodes in clud ing det ipt ic ionlogical s, rev iew LU N or eop e- sp f ie s—serv Some oper atailed e on descr a specif un itquest . The ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ed Log ical Unit Num ber ( LUN) field ( 8 b yt es) ident if ies w hich logical u nit shou ld b e oper at Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy on. I f t h e opcode d oes not relat e t o a logical u nit , t h is field is eit her ign ored or m ay be used syst em g et a hod m or, eas r ealist real- w or ld n et w or k ing en vir onm ent s in w hich in s,a pr unovid iqueinm m andicatpict ed ur bye tof het he specific opcode. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr oduIct an dt aim iciency, ing t he ar eader m ake mor eiSCSI in t elligent - eff icient niivt it iayt or skprt ov age—eff The init iathelp or assigns t ask t ag t o each t ask ,it cost issues. While a decisions for t h eir net w ork s. t ask exist s, t his t ag m u st un iq uely ident ify t he t ask session- w ide. This com pon en t is 4 by t es long. AH S— The Add it ion al Header Segm en t is op t ional an d is u sed only w hen an addit ion al com man d h ead er is requ ired. The AHS is a m iniheader consist in g of it s own lengt h, t y pe code, and com man d in fo.

D a t a fi el d— This ar ea is w her e t he act ual dat a is t r ansfer red. This could be SCSI dat a fr om a re a d com m and or login credent ials w it h in a log in com m and. The lengt h of t h is field v aries, bu t m ust abide b y t he m ax imu m MTU of t h e Et h er net fr am e.

Figu r e 5 5 -1 2 . iSCSI Fr a m e For m a t •

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[ View full size im age] I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

iSCSI Services

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

This sect ion ou t lin es a ser ies of iSCSI net w or k ser v ices t h at ar e p art of an over all iSCSI SAN I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat solut ion. enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Directory Com plet e wServices it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w orinit kiniat g porrof essionals, of ext opert ise. iSCSI s can use sevr egar er al dless m et h ods locat e iSCSI t ar get s. Most im p lem ent at ions t oday simp ly use a st at ic m app ing t o t h e I P ad dr ess of t h e iSCSI ser v er host ing a ser ies of t ar get s. Reader s ,wtill a g reats er unau der st an LANe and WAN tnar etget w or. kTh ing, ly tas h eI ETF How ev er w oobt main echanism can t om atding icallyoflocat an iSCSI ey pararet icu d eflar ined har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on dr af t s. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions tThe o enf ir sustremcon ceptism comp r eh en and r etLocat en t ion, dit ional f oresfuiSCSI rt her serv st udy . to echan is usin g tsion he Ser vice ionand Pr otad ocol ( SLP)r.esou SLPrrces equir ers Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy r eg ist er each of t heir t ar get s using a set of ser vice URLs, one for each addr ess on w h ich t he syst emm s,ay pr ovid in g a m orIenit r ealist pict urer e of t he realwsorusing ld n etSLP w or kser ingv ice en vir onm w hich t ar get b e accessed. iat or sicdiscov t hese t ar get r equ estent s, swin hich are pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease gener ally mu lt icast requ est s. iSCSI ser ver s t hat hear t h e SLP requ est s r espond w it h a list of pr ctle iv itt ar y get an ds.im ov er alized eff iciency, t he m ake in t elligent , cost icient avodu ailab Apr cent dir ecthelp or y ing ag en t ( rDeader A) m ay alsomor be eused f or iSCSI ser- eff v ers to decisions for t h eir net w ork s. r eg ist er t ar g et s and for iSCSI init iat or s t o acqu ire in for m at ion ab out t ar get s. The second m echan ism f or an iSCSI init iat or t o locat e t ar get s is t h rou gh a p rot ocol called I nt er net St or age Nam e Ser v ice ( iSNS) . Using iSNS, iSCSI init iat or s and t ar get s can locat e each ot her t h r ough a d irect or y ser v er .

The iSNS pr ot ocol facilit at es con figu rat ion an d m anag em ent of iSCSI dev ices in an I P net w or k by pr ov iding a set of d ir ect or y ser v ices comp ar able t o t hat available in Fib re Chan nel net w or ks. Using t h e iSNS pr ot ocol, iSCSI d ev ices au t om at ically r egist er t heir at t r ibut es w it h an iSNS ser v er. The iSNS serv er t her eby ser v es as t he con solidat ed config ur at ion p oint t hr ough w hich m anagem ent st at ion s can conf igur e an d m an age t he en t ire iSCSI st orag e net w or k. I n add it ion, t he iSNS ser v er can sen d not ificat ions ab out iSCSI dev ices or n et w or k ev en t s t o in t er est ed or aff ect ed dev ices. •

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Authentication Services I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

On e nice benefit of iSCSI is it s inclusion of au t hent icat ion ser v ices in t he login pr ocess. Wh en an iSCSI n ode logs in t o an iSCSI t ar get , usually an iSCSI gat ew ay , aut h en t icat ion can be per for m ed Pub lish er: Cisco Press against t he iSCSI init iat or befor e access is g r ant ed t o t h e t ar get . Alt hou gh sev er al p r ot ocols can e: Sep tem ber 1 1, 2 003 be uPub sedDatfor t his au t hent icat ion, t w o pr imar y m et hod s ar e used t o per for m a secur e connect ion I SBN: 58 705 19 -2 fr om iSCSI 1host t o-1iSCSI t ar g et . Pages: 11 28

The f ir st m et h od is t o u se Challen ge Hand sh ake Aut hent icat ion Pr ot ocol ( CHAP) , w h ich is m andat ed by t he iSCSI st an dar d an d is a com mon m ech anism used in I P d ialu p conn ect ions. Using CHAP, t ar get s can challenge iSCSI init iat or s, and v ice v ersa. A conv en ient im plem ent at ion m et hod is t o u se a cen t r alized RADI US serv er t o p r ovide a cen t r alized aut h en t icat ion engin e for iSCSI g at ew s. ion RADI st-andar pr otinocol p oses.p rov ides cover age of The u pdat eday edit ofUS t heisbaest sellingd alloneused net wfor orksuch ing r pur ef erence essent ial an d cu t t ing- edg e t ech nologies. The second m et h od u sed for aut hent icat ion is t he Secur e Rem ot e Passwor d ( SRP) pr ot ocol. SRP is a passw or d- b ased aut h en t icat ion and k ey- ex ch ange p r ot ocol, pr ovidin g au t hent icat ion ( opt ion ally muov t ual ion) and he n eg ot iat k ey. The prlev ot ocol Con cise er v au iewt hent s of icat t echn olog ies tessen t ial t o ion n et of wora ksession ing pr ofession alsSRP at all els, can f rom also be used t o open a secur e an d au t hent icat ed conn ect ion bet w een iSCSI in it iat or s an d nov ice t o ex pert . t ar get s. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP eragServices e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age iSCSICov Boot Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Man y diskless client s ar e conf igur ed t o boot f rom rem ot e SCSI devices. Th is capabilit y also exist s for diskless s b oot st rap ping ofbook f Fibr,eFour Chann el devices. ch pr d isk less entrefer it ies ence ar e t hat I n t ern et w or kclient in g Tech nologies Hand t h Ed it ion , is aSu com ehensive light w eight , spaceef ficient , and pow er con ser v in g and are in cr easin gly pop ular in enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int ervar netious w ork ing env iron ment s. Using t hese r em ot eboot ser v ices, new CPUs can be q uickly inser t ed o eit er ing add t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s tnet w hork capacit y or r eplace failed u nit s. These new dev ices r eplace t he ex ist ing d ev ices an d sim ply b oot indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . and un et he e iman age. Com rplet w itsam h new d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all The ETF oressionals, age w or kinr g g rou p has isedise. a p rop osal t o sup por t r em ot e iSCSI boot net wIor kinIgP pstrof egar dless of dev ex pert capabilit ies called dr aft - iet f- ip s- iscsi- b oot . This pr oposal descr ibes a mechan ism t h at let s clien t s boot st r sapw tillhem p rding ot ocol. Th e and goal WAN of t his t o t let iSCSI Reader obtselv ain es a gusin reatgert he un iSCSI der st an of LAN n etstwand or kard ing,isp ar icu lar ly t hboot e client in forand m atser ionv ices t o open aned iSCSI session w itt hech annology iSCSI inf boot ser ion v er .is pr ov ided on har dwsarobt e, ain pr ott he ocols, inv olv . Fu ndam ent al or mat a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary This chap t er pr ov id ed a br ief int r od uct ion t o st or age ar ea net w or kin g. SANs ar e r apidly becom in g cr it ical infr ast r uct ur e com ponent s of t oday 's ent er pr ise env ir onm ent s. Wit h t h e cont inu al gr ow t h of st orag e r eq uir em ent s, t h e ch alleng es associat ed w it h st or age ar e r apidly •becom in g n etTable Content s ges. wor kofing challen •

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IAntberrn et w k ing Te chnologie s H ers a ndbook , Fourt th ief ovorer v iew of t he d riv leading o tEdit he ion d ev elopm en t of SAN t ech nologies and solu t ions w as pr esent ed . SANs pr im arily f ocu s on opt im izing bot h usage an d access t o ent er pr ise st or age By Cisco Systems, Inc. r esour ces. SANs also help solv e m any of t he pr ovisioning challen ges associat ed wit h st or age b y enabling m or e- f lex ible an d less- d isr up t ive st or age deploym ent . Pub lish er: Cisco Press

Pub DatSAN e: Separ temch ber 1 1, ur 2 003 A t yp ical it ect e w as p resent ed t hat ou t lined t he v ariou s comp onent s of a SAN, I SBN: 158 705 -1 19 -2 includin g h ost s, d isk s, t apes, and v ar ious net w or k in g d ev ices. I n add it ion , a f un ct ion al m odel w as prPages: esen t11 ed28t h at r elat ed nod es of a SAN as eit h er in it iat ors or t ar get s. These roles ar e dir ect ly der ived fr om t h e SCSI p rot ocol. Th e SCSI p rot ocol is t he pr im ar y pr ot ocol t r anspor t ed over SANs.

A m or e in- d ep t h ex plor at ion of Fibr e Chann el w as pr esent ed t hat included man y of t he pr ot ocol' s st r uct ur al at t r ibu t es, such as ad dr essing schem es, rou t ing pr ot ocols, flow cont r ol, conn ect ion The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t y pes, net w or k t opologies, and dist r ibut ed ser v ices. essent ial an d cu t t ing- edg e t ech nologies. Finally, a br ief in t r oduct ion t o iSCSI was pr esent ed. iSCSI is a p rot ocol t hat is dr aw in g t r emend fr om er prolog ise ies I T or ganizat se itprrofession ep resentals s aatw all ay lev t o lev Conous ciseint overerest v iew s of ent t echn essen t ial ion t o ns,etbecau wor k ing els,erfage rom exist ing Et h er n et infr ast r uct ur es for SAN deploy m en t . An over v iew of iSCSI w as pr esent ed, nov ice t o ex pert . descr ibin g it as an alt er nat iv e t r ansp ort for SCSI com mu nicat ion. iSCSI ar chit ect ur al com ponent s, such it s com m erag unicat mpor od el, f r ame forlike m atVoI , and associat New chapt er sas include cov e ion of im t ant t opics P and EAP ed net w or k ser v ices, w ere also pr esent ed in d et ail. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What is a st or age area net w ork ( SAN) ?

2:

I ndext w o pr im ar y t r anspor t pr ot ocols are used w it hin a SAN? What

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Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 :Systems, What Inc. pr im ar y By Cisco 4:

upp er - lay er com m un icat ion pr ot ocol is t r anspor t ed over a SAN?

What t w o pr im ar y r oles are assum ed by SCSI devices?

Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003

5:

Nam e t hr ee up per- lay er pr ot ocols besid es SCSI t hat w ere adapt ed t o t h e Fib r e

I SBN:Ch 1- 58 705 -1t19 -2 annel r anspor t. Pages: 11 28

6:

What gov ern ing body pr esides ov er t he Fibr e Ch annel p rot ocols st and ard s and dr af t s?

7:

When w as t he fir st Fibr e Chan nel st andar d app rov ed, an d wh at w as it called?

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of : an What er edg of t ehet ech Fibrnologies. e Chan nel pr ot ocol m odel is r esponsible f or est ab lishin g essent8ial d cu tlay t ingcom mu nicat ion b et w een t wo por t s in a SAN? Con 9 : cise Nam oveert he v iew t hr s ee of tcom echn molog on Fibr ies essen e Chann t ialelt onet n et w wor ork kt ing opologies. pr ofession als at all lev els, f rom nov ice t o ex pert . 1 0 : How m any devices can an ar bit r at ed loop supp ort ? New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP 1 1 : What is t h e diff er ence bet w een a pr ivat e arb it rat ed loop and a p ublic ar bit r at ed Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age loop? Sy st 1Aut 2 : h ored Whatbyis Cisco a B_Por t ?ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat 1 3 : What is t h e nam e of t he pr im ar y Fibr e Ch annel r out in g p rot ocol, an d w h at p art of enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing an FC_I D does it u se t o m ake rou t ing decisions? t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . 1 4 : What is a Fibr e Chann el I D LE, and w hat is it used f or ? Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all 1 5 : What Fibr e Chan nel class of ser vice does n ot pr ov ide d eliv er y conf irm at ion of net w or kin g p rof essionals, r egar dless of ex pert ise. fr am es? Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e 1 6ar: e, What is t h eand ru leser ofvtices huminv b in owalmt ech anynology bu ff er inf cr edit s arion e r is equir edided t o on har dw pr ot ocols, olvdet ederm . Fu ining ndam hent or mat pr ov sust ain wir e r at e capab ilit y acr oss a 1 Gbp s Fib re Chann el lin k? a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . 1 7 : e is What soft Cov erag also is ext endzoning ed n ot?only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich 1 8 : Tr ue or at f alse: An inand div id iSCSI f or ex chang e can syst b e conduct ed mover lt ipincr le TCP pr of essionals oper e. Tools guual id elines opt im izing em per for ancemwu ill ease connect ions. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. 1 9 : What st and ard TCP por t num ber is u sed for iSCSI ? 20 :

Nam e t w o m echanism s for p er f orm ing iSCSI in it iat or aut h en t icat ion .

For More Information Books •

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erchnologie t W. Fib re el:, Four A Com prion ehensiv e I nt r oduct ion . Tu cson: Nor t hw est Lear ning I• nt Kem e rn etbel, w or k Rob ing Te s HChann a ndbook th Edit Associat es, I nc., 200 0. By Cisco Systems, Inc.

Pub lish er: Cisco Press

URLs Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

• w w w .f ibr ealliance. org • w w w .iet f .or g/ ht m l.char t er s/ ip s- ch art er . ht m l The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of •essent w w w .sear e. com ial anch d stcuort tag ingedg e t ech nologies. • w w wCon .snia. or g cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . • w w w .t 11. or g New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 56. IBM Network Management Obj e ct i ve s • •

Table of Content s

Discuss con figu r at ion m anag em ent . I ndex

I nt e rn Discuss et w or k ingper Te chnologie s Hand a ndbook , Four th Edit ion for m ance accou nt ant m anagem ent . By Cisco Systems, Inc.

Discuss pr oblem m anagem ent . Pub lish er: Cisco Press

Discuss oper at ion s m anagem ent .

Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 -1 19man -2 Discuss ch705 ange agem en t . Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background I BM net w or k m anagem en t r efer s t o any ar chit ect u re used t o m anage I BM Syst em s Net w ork Ar ch it ect u re ( SNA) net w or ks or Adv anced Peer- t o- Peer Net w or kin g ( APPN) net w or ks. I BM net w or k m anagem ent is p ar t of t h e I BM Op en - Net w or k Ar chit ect ur e ( ONA) and is perf or med •cen t r ally b y using Table ofmContent s ent p lat for m s such as Net View an d ot hers. I t is div id ed int o fiv e anagem •fu nct ions t h at I ndex ar e sim ilar t o t h e net w or k man agem en t f unct ions sp ecified und er t he Op en ISy nt st e rn et wIor ing Te chnologie H a ndbook , Four th Edit em n tker connect ion (sOSI ) m odel. This chion apt er sum m arizes t he I BM net w or k m anagem ent fu nct ional ar eas, ONA n et wor k m an agement ar ch it ect u re, an d m anag em ent plat f orm s. Figur e By Cisco Systems, Inc. 56 - 1 illust r at es a b asic m an aged I BM net w or k. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2

Figu r e 5 6 -1 . I BM N et w or k M an ag em e nt Ha nd le s SN A or APPN Ne t w or k s

Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IBM Network-Management Functional Areas I BM d ivides n et w or k m anag em ent int o t he f ollow ing f iv e u ser - based f unct ions: con figu rat ion m anagem ent , p er f orm ance an d accoun t ant man agement , pr oblem m anag em ent , op er at ions m anagem ent , an d chan ge m anag em ent . •

Table of Content s

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

IBM Configuration Management By Cisco Systems, Inc.

I BM conf igur at ion m an agem ent con t rols in for m at ion d escr ib ing t he p hy sical an d log ical lish charPub act erer: istCisco ics ofPress n et wor k r esour ces, as w ell as t h e r elat ionship s bet w een t hose r esou rces. A Pub Dat e: Sep tem ber 003 cen t r al m anagem ent1 1, sy2st em st or es dat a in con figu rat ion m anag em ent dat abases and m ight I SBN: 158 705 -1 19 -2 include in for m at ion su ch as sy st em sof t w are or m icr ocode v er sion num ber s; ser ial n um ber s of har dwPages: ar e or11sof 28 t w are; phy sical locat ions of net w ork d ev ices; and nam es, addr esses, and t elep hone n um ber s of cont act s. As m ight be ex pect ed , I BM conf igur at ion m anagem en t corr espond s closely t o OSI configu r at ion m anag em ent . Con figu rat ion - man agem en t f acilit ies aid in m aint aining an inv ent or y of net w or k r esour ces and in ensur ing t hat net w or k con figu rat ion chan ges ar e ref lect ed in t h e con figu rat ion - m anagem en t The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of dat ab ase. Conf ig ur at ion man agement also pr ov ides inf orm at ion t hat is used b y pr oblem essent ial an d cu t t ing- edg e t ech nologies. m anagem ent and ch ange- m anag em ent sy st ems. Pr oblem - m anagem en t sy st em s u se t his inf orm at ion t o com par e v ersion diff erences and t o locat e, ident if y , and check t he char act erist ics of netCon w orcise k r esour e- man agement use t hkeing infor at ion tals o anataly t hels, e efff ect ov erces. v iew Chang s of t echn olog ies essensyst t ialem t o sn et wor pr m ofession allzelev romof changnov es and t o schedule chan ges at t im es of m inim al net w or k im pact . ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

IBM Performance and Accounting Management

Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

I BM per m ance account ing m anagem p r ovides or king mat ion outI ntthe Autfor h ored by and Cisco Sy st ems, w or ldw ideent leader in netinf w or f or ab t he er nper et . for m ance of net w or k r esour ces. The f unct ions of t h e per for m ance- and account ing - m anagem en t f acilit ies include g r esp onse t im es of sy st ems;t hmeasur ilitehensive y of r esourefer r ces; m easu I n t ern et mon w or kitinorin g Tech nologies Hand book , Four Ed it ioning , isav a ailab com pr ence t hatrin g tenables he use of r esour ces; and t un in g, t r ack in g, an d con t rolling net w or k per for m ance. The net w or kin g p r ofessionals o un derst and an d im plem en t cont em por ar y int er net w ork ing inf orm at ion gat h er er ed tby or mcep ancent ing agemused en t f unct ions ' is usef t echnologies. Mast he t heremperf s, con t s, tand echnaccou ologies, an-dman devices in t oday s net w ul orkf or ing det er min in g w h et h er net w ork perf or man ce goals ar e being m et and w het her p rob lem indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . det erplet mineatwion rocedur should be in er it iat ed secur basedit yon p or er fage, orm an ce and y, Com it h pnew an d es u pdat ed chapt s on , st optce. icalI BM net perf w or korinman g, scalabilit accou nt ing m anag em ent perf or ms fun ct ion s similar t o t hose h andled b y OSI p er f orm an ce and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all m anagem ent and OSI account ing m anag em ent . net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on IBM Problem Management a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ICov BM erag pr oblem m anagem ilart ot onew OSInfau lt mk anag em entt s, in but t h atalso it hand leserer or condit ions e is also ext enden edt nisotsim only et wor ing concep t o old , rlegacy tsyst hat em cause users t o lose t he full fun ct ion alit y of a net w or k r esour ce. Pr oblem m anagem en w t is s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in hich per for m ed in fiv e st eps: p rob lem d et er m inat ion, p r oblem diagnosis, pr oblem b yp ass an d pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease rprecov esolu ion, an d p rhelp oblem ackring andmcont ol. e in t elligent , cost - eff icient oduery ct iv, itpyrob anlem d imrpr ov et eff iciency, ingt rt he eader ake r mor decisions for t h eir net w ork s. Pr oblem det erm inat ion consist s of det ect in g a pr oblem and com plet in g t he st eps n ecessar y for beginn ing pr oblem diagn osis, such as isolat in g t he pr ob lem t o a p ar t icu lar su bsyst em . Pr oblem diagn osis con sist s of det er m in ing t he p recise cause of t h e pr oblem and t h e act ion r equir ed t o solve it . Prob lem by pass and r ecov er y consist s of at t em pt s t o by pass t h e pr oblem, eit h er par t ially or com plet ely . I t p r ovides on ly a t em por ary solu t ion an d r elies on p rob lem r esolu t ion t o solve t he pr oblem p er m anent ly . Pr oblem r esolut ion consist s of ef for t s t o elim inat e t he pr oblem .

I t u su ally begins af t er pr oblem diagn osis is com plet e an d of t en in volv es cor r ect iv e act ion, such as t h e r ep lacem en t of f ailed har dw ar e or soft war e. Pr oblem t r acking an d cont rol con sist s of t r acking each p r oblem unt il final resolut ion is reached. Vit al in for m at ion descr ibing t he pr oblem is r ecor ded in a pr oblem dat abase.

IBM Operations Management •

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•I BM oper at ion I ndex s m anagem en t con sist s of m anag in g d ist r ibu t ed n et w or k r esou rces f rom a cen t r al Isit nt e, e rnusing et w or kting chnologie s H aions: ndbook Editm ion w oTe set s of fu nct op, Four er atth ionsanagem ent

ser vices and comm on - operat ion s serCisco v ices. Op er atInc. ions- m anag em ent ser v ices pr ov ide t he cap abilit y t o cont rol rem ot e r esou rces By Systems, cen t r ally u sin g t he f ollow ing f unct ions: r esour ce act iv at ion and deact iv at ion, com m and cancellat ion,Cisco andPress clock set t ing. Oper at ions- m anagem en t serv ices can be in it iat ed aut omat ically Pub lish er: in response t o cer t ain syst em pr oblem n ot ificat ions. Pub Dat e: Sep tem ber 1 1, 2 003

I SBN: 705 -1 19ser -2 vices allow for t he m anag em ent of resour ces n ot ex plicit ly ad dr essed b y Com m onop1-er58at ions 11em 28 ent ar eas, u sin g specialized comm un icat ion t h rou gh new , m ore cap able ot her Pages: m anag app licat ions. Comm on - operat ion s ser v ices of fer t w o im por t an t serv ices, t h e e xe cut e com m and and t h e resour ce- m an agement ser v ice. Th e e xe cut e com m and pr ov ides a st and ard ized m eans of execut ing r emot e com m and s. The r esou rce- m anagem en t serv ice pr ov id es a w ay t o t r anspor t inf orm at ion in a cont ex t - independ en t m ann er . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

IBM Change Management Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom I BM change nov ice m t oan exagem pert . ent t rack s net w or k chang es an d main t ain s chang e files at r em ot e nod es. Net w ork ch anges occur pr im ar ily f or t w o reasons: chan ging user r eq uir em ent s an d pr oblem circum v entchapt ion. Chang in g user en tpor s include har dw ar e and soft w ar e up gr ades, new New er s include cov requ erag ir e em of im t ant t opics like VoI P and EAP app licat ions and ser vices, and ot her f act ors t hat con st an t ly chang e t he n eeds of n et wor k u ser s. Pr oblem Cov cir erag cum e of v encut t ion t ing is edge need ed t echn t o deal ologies w it lik h unex e optpect ical ed n etchang wor k ing es rand esultsting or age fr om t h e failur e of har dw ar e, soft w ar e, or ot h er net w ork com pon en t s. Chan ge m anag em ent at t emp t s t o min im ize Autsh by ored by Cisco Syder st ems, wwororldw ide leader net or kingchang f or t he I n t erwh n etich . log net w or k pr oblem p rom ot in g or ly net k changes anin dm anwaging e files, chang es. I BM ch ange man agem en t is sim ilar in som e r espect s t o OSI accou nt ing m anag em ent . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IBM Network-Management Architectures Tw o of t h e m ost w ell- k now n I BM n et wor k - m anagem ent ar chit ect ur es are t he Op en - Net wor k Ar ch it ect u re ( ONA) an d Sy st emView . •

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Open-Network Architecture I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

The Op en - Net w or k Ar chit ect ur e ( ONA) is a gener alized net w or k- m an agement ar ch it ect u re t hat defin es four key m anag em ent en t it ies: t he f ocal point , collect ion poin t , ent r y point , and ser v ice Pub point . lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

The f ocal point is a-1 19 man I SBN: 1- 58 705 -2 agem en t ent it y t h at p rov ides sup por t f or cen t r alized net w or km anagem ent operat ion s. I t r espon ds t o end- st at ion aler t s, m aint ains man agem en t d at abases, Pages: 11 28 and pr ov ides a u ser in t er f ace f or t h e net w or k- m anag em ent oper at or. Thr ee kind s of focal p oint s exist : pr imar y , second ar y, and nest ed. The p rim ar y focal p oint s p er for m s all f ocal point fu nct ions. The secondar y f ocal point act s as a backu p f or pr im ar y focal p oin t s and is u sed w hen pr im ary focal poin t s fail. Th e nest ed f ocal point pr ov id es dist rib ut ed m an agement supp ort in lar ge net w or k s. Nest ed f ocal point s ar e responsible f or f orw ar ding cr it ical in for m at ion t o m or e The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of global focal p oin t s. essent ial an d cu t t ing- edg e t ech nologies. Collect ion poin t s r elay in for m at ion f r om self - con t ained SNA su bnet w or k s t o f ocal point s. Th ey ar e comm on ly used t o for w ar d d at a f r om I BM p eer - t o- peer net w or ks in t o t h e ONA h ier ar chy . Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . An en t r y point is an SNA dev ice t hat can im plem ent ONA f or it self an d ot her dev ices. Most st andar d SNA d ev ices ar e capab le of being en t r y point s. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP A ser vice point is a sy st em t hat pr ov id es access int o ONA f or non- SNA devices and is essent ially Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age a g at eway in t o ONA. Ser v ice point s ar e capab le of send ing man agem en t inf or mat ion abou t n onSNA sy sthem s t obyfocal p oint s,ems, r eceiving com ands f rin omnet focal ointfs, anslat ingn et comm an ds int o a Aut ored Cisco Sy st w or ldw idemleader w or pking ort rt he I n t er . for m at accept ab le t o non - SNA dev ices, and f orw ar din g com m ands t o non - SNA dev ices f or execut ion. I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Figur e 56 - 2 illust r at t het errelat weenologies, t he d if fer ONA mused anagem ies. t echnologies. Mast erest he m s,ionships con cep t b s,ett echn anen d tdevices in tent odayen ' st itnet w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Figu e 5g 6p rof -2 essionals, . Th e Fou r Typ esof of Foca net w orrkin r egar dless ex pert ise.l Poi nt s Lin k t o On e An ot h er W it h in

t h e O NA Env ir on m en t

Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

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I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

SystemView I n t ern et w or k in g Tech nologies Hand book , Four t h

Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. er t he m s, coning cepm t s,anagem t echn ologies, an d ion devices in t oday of ' s net w orking ing Sy st em View isMast a bluepr intt er for cr eat ent ap plicat s t hatused ar e capable m anag indu Learinf n or how o incor int er net w or kin g t echn olog ies in t o aions LAN/ env ireonm ent . m ultst iv ry en.dor mattion sy stpor emat s.eSyst em View descr ibes how applicat t hWAN at m anag Com e w it h new pdat ede chapt er her s onmsecur it y , en st or age, opt w or in g, scalabilit het erplet ogeneous net wan or d k suoperat w it h ot anagem t sy st em s.ical I t isnet t he offkicial sy st ems y, and speed,ent t h is u p-Ap t o-plicat d at e ion r ef er t o ur t he m anagem st rbook at egyisofa tcom h e Iplet BM eSyan stdems Arence chit ect e. t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

IBM Network-Management Platforms I BM n et wor k m anag em ent is im plem ent ed on sev er al p lat for m s, inclu ding Net View , LAN Net w ork Man ager ( LNM) , and Simp le Net w or k Man agem en t Pr ot ocol ( SNMP) . •

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NetView I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

Net View is a com pr eh en siv e I BM ent er pr ise net w or k- m anag em ent plat f orm t hat pr ovid es cen t r alized SNA net w or k - man agem en t serv ices. I t is used on I BM m ainf r ames an d is p art of t he PubNet lish er: Ciscoconsist Press s of t he com man d- cont r ol f acilit y , h ard w are m on it or, session m onit or , help ONA. View Pub Dat e: Sep tem 1 1,or2,003 fu nct ion, st at u s mber onit per for m ance m onit or , and d ist r ibut ion m onit or . I SBN: 1- 58 705 -1 19 -2

The com m andPages: 11 28con t rol facilit y pr ov id es net w ork con t rol by issu ing basic oper at or and f ile- access com man ds t o Virt u al Telecom m unicat ions Access Met h od ( VTAM) app licat ions, con t roller s, oper at ing syst em s, and Net View / PC ( an in t er f ace bet w een Net View an d n on- SNA d ev ices) . Th e har dw ar e m onit or fun ct ion m onit or s t h e net w or k and aut om at ically aler t s t h e net w or k operat or w hen har dw ar e err or s occu r . The session m onit or act s as a VTAM p er f orm an ce m on it or and pr ov ides soft w ar e- pr oblem det erm inat ion and conf ig ur at ion man agem en t . The h elp f unct ion The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of pr ov ides help f or Net View user s an d in clu des a b row se f acilit y , a h elp desk facilit y, and a libr ar y essent ial an d cu t t ing- edg e t ech nologies. of comm on ly en cou nt er ed net w or k oper at ion sit uat ion s. The st at us mon it or sum m arizes and pr esent s net w or k st at us inf or mat ion . The p er f orm an ce m on it or fu nct ion m onit or s t he per forCon m ance t - en ocessor ( FEPs) , tthe k Cont og ramals ( NCP) , an ot h er cise of ov fr eron v iew s dof pr t echn ologs ies essen ial Net t o nwetorwor k ingr ol pr Pr ofession at all levd els, f rom at t ached r esour ces. Th e dist r ib ut ion m anager p lan s, schedu les, an d t rack s t he dist ribu t ion of nov ice t o ex pert . dat a, sof t w ar e, and m icr ocode in SNA env iron ment s. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing LANCov Network Manager

and st or age

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The LAN Net w ork Manager ( LNM ) is an I BM net w ork - m anag em ent applicat ion t hat con t r ols Tok en et Rin g kLANs fr omnologies a cen t ral su ppor e. LNM an ,OS/ Ext end ed Edit ionbased oduct I n t ern w or in g Tech Hand bookt ,sit Four t h Edisit ion is a2 com pr ehensive refer enceprt hat tenables hat int ernet oper at es wit h I BM Net View ( w hich is aw are of su ch LNM act ivit ies as alar m s) and h er w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ot ing It echnologies. BM m an agement soft w ar e. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed,Network t h is book is a com plet e an d uProtocol p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Simple Management net w or kin g p rof essionals, r egar dless of ex pert ise. IReader BM n etswor m anag ent er canunbder e imp lem entof edLAN by uand singWAN SNMP. t o Ch apt er lar 58ly , "tSim w illk obt ain aem g reat st an ding n etRefer w or k ing, p ar t icu h e ple Net w ork Managem ent Pr ot ocol, " f or det ails abou t SNMP imp lem ent at ion. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1:

What ar e t he fiv e st ep s of pr oblem m anagem ent ?

2:

I ndex How d oes t he com man d- cont r ol f acilit y of t h e Net View p r ogr am oper at e?

• •

Table of Content s

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

3 :Systems, To p erInc. f orm By Cisco

r esour ce act ivat ion and deact ivat ion , com man d can cellat ion, and clock set t in g on a r em ot e sy st em , y ou w ould need t o use w hat ?

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 57. Remote Monitoring Obj e ct i ve s • •

Table of Content s

Descr ibe t he back gr ound of Rem ot e Mon it or in g. I ndex

I nt e rn Descr et w or kibe ing Te chnologie s H a ndbook , Four Editit ion t he nin e RMON gr oup s ofthmon or in g. By Cisco Systems, Inc.

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand b