286 95 1MB
Russian Pages [87]
Ы .
.
. .
-
__________________________________________________________________________________________
. .
, . .
«IP-
, . .
NGN»
200900 –
2006 1
621.391.18:658.512.22
2007/2008
«IP-
NGN» ,
2009 –
: . .
, . .
, . .
,
,
.323, IP-
:
.248
SIP,
,
NGN.
. . .,
. .
. . .,
. .
26
2006 .
№ 11.
2
1. 1.1. 1.2.
...................................................................................................................................5 IP..................................................................................................8 IP.......................................................................8 IP....................................................................12
1.2.1. 1.2.2. Э 1.2.3. 1.2.4. 1.2.5.
IP........................................................................................................ 12 .................................................................................................................................... 15 IP.............................................................. 15 , ITU- ................................................................................ 18 , ETSI.................................................................................. 19
1.3. RTP .............................................................................................................19 2. H.323...............................................................................................................................21 2.1. .323 .............................................................................................21 2.1.1. 2.1.2. 2.1.3. 2.1.4. 2.1.5.
2.2. 2.2.1. 2.2.2. 2.2.3.
2.3. 2.4. 3. 3.1. 3.2. 3.3. Э 3.4. 3.5. 3.6. 3.7. 4. 4.1. 4.2. 4.3. 4.3.1. 4.3.2.
4.4. 4.4.1. 4.4.2. 4.4.3. 4.4.4. 4.4.5.
4.5. 4.6. 4.7. 5. 5.1. 5.1.1. 5.1.2.
5.2. 5.2.1. 5.2.2.
5.3. 5.3.1.
.323
.323............................................................................................................... 22 .323 ..................................................................................................................... 24 ...................................................................................................................... 24 ...................................................................... 26 ............................................................................................ 27
H.323 ........................................................................................................27 RAS ................................................................................................................. 27 .225.0 ............................................................................................. 34 H.245 ............................................................................................ 35
c
.......................................................................................39 .................................................................................................40 IPSIP ......................................42 ..............................................................42 ....................................................................................................................43 SIP......................................................................................................44 SIP ............................................................................................................46 ...........................................................................51 .......................................................................................53 .................................................................................................54 ................................................................................56 ......................................................................56 MGCP .........................................................................................................57 MEGACO/H.248 .....................................58 (Terminations)............................................................................................... 58 (Context)........................................................................................................... 60
H.248/MEGACO...................................................................60 .................................................................................................................... 61 ........................................................................................................................... 62 ....................................................................................................................... 63 ....................................................................................................................... 63 (Packages) ........................................................................................................... 64
..............................................64 .......................................................................................68 ................................................................................................68 ................................................................................................69 I ...........................................................69 ............................................................................................ 69 .................................................................................. 73
............................73 ................................................................................................ 73 .................................................................................. 76
.............................77 ................................................................................................ 77
3
5.3.2.
5.4. 5.4.1. 5.4.2.
5.5. 5.5.1. 5.5.2.
.................................................................................. 78
Linux...................................................................78 ................................................................................................ 78 .................................................................................. 81
...........................................................81 ................................................................................................ 81 .................................................................................. 86
.................................................................................................................87
4
IP,
Voice over IP (VoIP)
IP-
,
, IP. -
IP-
, .
IP:
(1980 - 1995),
(1995 - 1999), ,
. . 1983 К
IP,
. VocalTec,
1995 (DSP),
,
,
.
,
VocalTec
PC – PC. ,
.
1996
16-
(ITU-T) H.323, (QoS). Э
«
-
»
IP.
И
, IP-
IP-
IP,
,
, , , . IPH.323.
, , ,
MGC (Media Gateway Controller)
Softswitch, 5
, MG (Media Gateway).
,
1998
MGCP (Media Gateway Control Protocol), 16 ITU-T
IETF
,
2000
H.248
MEGACO.
SIP, . ,
,
RTP. ,
IP-
. .
, ,
.
, .
IP-
, . 1996
-
CompTek IP-
,
VocalTec,
VocalTec .
,
.
,
IP-
?
,
IP-
. -
.
IP-
« VocalTec,
».
IP. «
»
RGC.
«
»
, RGC . 1997 ,
,
IP-
.
.
, . 6
, IP-
.
VocalTec,
,
IP,
,
, IP-
.
Internet. . :
. IP-
, , ,
, IP-
. .
1(
30
),
,
. ,
1998 .
. 27
1998 .
( )
Э)
(
I -
.
-
–
,
(
41
). -
.1
1999 . IP-
«
». ,
,
IP-
,
,
. 2000
.
IP-
2001 .,
-Э –
-IP.
IP-
-IP .
,
2001/2002 .
,
.
. .
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. 7
1.
IP1.1.
IP,
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IP-
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Microsoft. «
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,
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IP-
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Linux.
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IP(VxWorks, pSOS, QNX Neutrino
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),
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ITU-T
G.114
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90
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toll quality. o 3-3.5 –
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.
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, . 1.2.4. К
,
ITU-
G.711 G.711 – « ITU-T ,
»
1965
.
MOS
,
VoIP
G.711.
G.723.1 G.723.1
ITU-T
1995
G.723.1
IP: 6.4
24 20
4.2.
, -
К
,
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.
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.
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189
/ (
158
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3.7
6.4
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5.3
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G.723.1 . К
G.726 G.726
24
16
40, 32,
/ ,
MOS
4.3 (32
/ ),
(toll quality). IP-
, . К
G.728 G.728 MOS,
G.726
16
/ .
( ) . К
G.729 G.729
Frame
Relay.
10
/ .
8 5
. : 18
G.729
ITU-T
1996 G.729A
G.729
ITU-T
VAD, CNG
1995
DTX.
, . 1.2.5.
,
ETSI ETSI (GSM). GSM Full Rate,
GSM 06.10,
1987 . ( 20
MOS
3.7
).
,
13
/c.
. Э IP-
,
, –
, ,
. GSM Half Rate, ,
GSM Enhanced Full Rate,
1995
1994
.
, .
IP-
, 1.3.
,
. RTP IPRTP (Real-Time Protocol), IPRTP
.
UDP, IP (
.1.6). 32
/
RTP
/
UDP IP Ethernet
. 1.6.
RTP/UDP/IP
19
(
)
RTP
,
. 1.7.
IP
IP
16 V
P
X
CC
M
RTP
RTP
UDP
32 №
PT
0 = 64 / 3 = 13 / 14 = MPEG 32 = MPEG1
GSM
SSRC CSRC
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, , V)
( 2).
VoIP ,
12
.
RTPRTP (
, RTP. :
P,
, -
(
, Х,
),
,
.
, . CSRC-
,
RTP-
, . . ,
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,
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, (Application Data),
,
), – . ..
8-
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,
. (SequenceNumber),
(Time Stamp) SSRC, .
,
,
, (
,
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. , SSRC-
, RTP-
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. 20
RTPCSRC-
15 .
,
RTP (Real-Time Transport Control Protocol), RTP.
RTCP , UDP-, RTPQoS (Quality of , QoS, , ).
,
Service). RTCP(
,
,
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32-
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)
, ,
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).
(
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,
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– ,
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,
.
2.
H.323 2.1.
.323 IP-
H.323
(ITU-T).
.323
,
. ITU-T
,
.
,
H.323, ISDN,
.
,
IPITU- Q.931
ISDN. H.323 , 21
, . Э
IP(
,
), IP
(
. 2.1).
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.323 IP-
Ш
Ш
.323 /ISDN
V.70
/ISDN
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,
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.323
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.323 .
2.1.1.
.323 H.323
–
IP-
,
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,
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,
( H.323
, NetMeeting).
, 22
, H.323
H.323, .
H.261, H.263
G.711, G.722, G.723, G.728, G.729 (T.120) H.225.0
H.245
H.225.0
RAS
. 2.2.
.323
, . : H.225, Э
.245
RAS.
, ,
,
,
. , ,
. . .120.
H.225.0
,
,
, IP,
.
, ,
,
.
.245,
.225.0 (Q.931) TCP ,
RAS,
UDP. 23
, . , (
), IP
,
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,
(
),
IP
,
.
,
.
,
2.1.2.
. .323 IP. (
) ,
,
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,
,
IP-
,
,
RTP/UDP/IP,
.
,
, .323.
, ,
DSS1
2
OKC7
.323.
–
IPIP,
.
,
,
. ,
,
.245, .
,
,
.323
.323,
IP-
,
. 2.1.3. IPITU H.323. (
. 1.4).
–
, .323 IP24
,
,
,
.
H.323 .
1 2 4
3 5
Ш
. 2.3.
.323 ,
•
, alias-
(
,
: ,
.) IP (IP-
•
TCP); IP-
RAS (
•
ARQ/ACF/ARJ);
,
•
; , ;
. ,
. .
. IP-
.
,
,
, 25
, E.164,
IP-
.
2.1.4. IP.
,
.323
(
–
.1.4).
, «
-
»
(MCU),
, . –
, «
-
»,
(
)
,
. –
, . .
. –
,
–
.
A D
B
E
F C
Ц
. 2.4.
;
.323
,
,
IP
(IP multicasting). ,
, ,
«
-
»,
. MCU –
(Multipoint controller, MC). 26
, MCU (Multipoint processor, MP). 2.1.5.
.323 H.323 ,
IP,
2-
. .
H.323
H.323
:
,
IP-
,
. 4
5 ,
,
4
,
H.323
, 2.2.
.
H.323 .323
: – RAS (Registration, Admission and Status), – H.225
.245,
– -
Q.931,
TCP/IP, UDP, RTP
RTCP,
.2.5.
TCP H.225
H.245,
RAS
UDP, RTP/RTCP.
UDP
.225 .245 RAS
(Q.931)
RTCP
TCP
RTP
UDP IP
. 2.5. 2.2.1.
H.323
RAS
ITU-T
.225.0 .323 –
(
,
, 27
. Э
)
RAS
(Registration, Admission and Status).
, RAS,
•
:
;
•
;
•
;
•
;
•
;
•
;
•
, . ,
H.323.
RAS,
H.225.0 (Q.931) .245.
: .245
H.225.0,
RAS .
,
. RAS
UDP. О , , .
,
,
.
,
,
. . –
. ,
,
,
.
, 1719 (2-
UDP )
1718 (1-
).
28
Gatekeeper Request (GRQ) IP-
(multicasting),
224.0.1.41 (Gatekeeper UDP Discovery Multicast Address)
UDP
1718 (Gatekeeper UDP Discovery Port). , GRQ,
,
rasAddress
Gatekeeper Confirmation (GCF) RAS (
. 2.6). ,
Gatekeeper Reject (GRJ).
GRQ GCF/GRJ
. 2.6.
GRQ
, ,
.
5
GRQ, . , . . , .
я
я , ,
, (
:
. .
. 2.7).
alias-
. Registration Request (RRQ)
, ,
. UDP
and Status Port).
,
1719 (Gatekeeper UDP Registration Registration
29
Confirmation (RCF)
Registration Reject (RRJ).
, .
RRQ
)
RCF or RRJ
)
URQ RCF/RRJ
URQ
)
UCF
. 2.7.
alias-
RRQ,
RCF.
,
RRQ
timeToLive .
RCF .
timeToLive,
, ,
RRQ
keepAlive. .
30
. ,
. ,
Unregister Request (URQ); Unregister Confirmation (UCF). alias-
. ,
URQ
Unregister
Reject (URJ). , Unregister Request (URQ), Unregister Confirmation (UCF).
,
, . Д
я , ,
, Setup,
Admissions Request (ARQ) (
.3.8),
. .
ARQ
,
ARQ,
,
.
alias,
alias-
,
,
/
ARQ
. ARQ
(
RTP/UDP/IP
).
ARQ ACF/ARJ
. 2.8. 31
,
Admissions Confirm (ACF),
. 2.8.
,
, , ,
,
. ACF Setup, .225.0. Setup .
,
Admissions Reject (ARJ). О
я
я (
RAS)
,
alias-
Location Request (LRQ).
,
, . Э
Location Confirmation (LCF),
(
.2.9).
LRQ LCF/LRJ
. 2.9.
,
RAS
LRQ,
Location Reject (LRJ), .
,
,
LRQ
Gatekeeper′s Discovery Multicast,
. ,
,
,
, .
,
, . 32
О
щ
я
я
я
. (
.2.10).
IRQ IRR
. 2.10.
(
)
Information Request (IRQ). IRQ 10
,
.
IRQ, Information Request Response (IRR).
О
я (
. 2.11).
Disengage Request (DRQ), Disengage Confirm (DCF).
DRQ DCF
. 2.11.
, ,
. .
DRQ.
DRQ,
, ,
DCF. ,
DRQ
. 33
2.2.2.
.225.0 H.323
ITU-
.225.0. Э Q.931. Setup .Э
TCP
1720
.
Call Proceeding
,
,
.
Alerting , . Connect ,
.
Connect
H.245. Release Complete .Э ,
. Q.932 Facility ITU-T H.450. .
TCP. ,
,
.225.0
, .
(Call Signalling Transport Address)
RAS
.
ARQ
alias-
. (Gatekeeper Routed Call Signalling), . (Direct Endpoint Call Signalling), . ,
, .
.225
, . 34
. ,
, .
. .
ISDN,
. ARQ
ACF
RAS
Setup
.
Setup
Call Proceeding,
,
,
,
,
. Alerting,
,
.
, Connect
H.245
, , H.245
,
.
,
,
,
H.245
Call Proceeding
Alerting.
2.2.3.
H.245 ITU-T H.245
, :
•
(Master/slave determination);
•
(Capability Exchange);
• • • •
(Open/Close Logical Channel Signalling); (Open/Close Bidirectional Logical Channel Signalling); , (Round Trip Delay Determination); (Mode Request); 35
•
, (Maintenance Loop Signalling).
( )
.245. (
,
) .
,
,
, ,
,
. .245
TCP
, .245
. .245
,
,
: .
-
, -
.
-
,
,
.
,
-
,
,
.
О
щ
я ,
,
, , .
(
. 3.12),
masterSlaveDetermination ,
terminalType , [0…(224-1)]. terminalType,
statusDeterminationNumber – , –
statusDeterminationNumber.
36
1
2
MSD
MSD
MSDAck (
MSDAck
)
(
)
. 2.12.
masterSlaveDetermination ,
masterSlaveDeterminationAck, ,
–
.
.323 ,
.
О
я
я
H.323,
,
,
.Э
,
.
, .
, (
.2.13). 1
2
MSD
MSD
MSDAck (
MSDAck
)
(
)
. 2.13.
TerminalCapabilitySet, , ,
. .
,
.
37
TerminalCapabilitySet
capabilityTable –
,
/
. alternativeCapabilitySet. (
)
,
.
,
simultaneousCapabilities.
(capabilityDescriptor),
(capabilityDescriptorNumber). ,
,
. TerminalCapabilitySet
,
,
,
. , TerminalCapabilitySet, TerminalCapabilitySetAck. , TerminalCapabilitySetReject.
,
TerminalCapabilitySet, ,
,
TerminalCapabilitySetRelease.
О ,
,
H.323
, .
.245 :
(uni-directional), . . ,
(bi-directional),
– .
Uni-directional Logical Signalling (
. 2.14).
38
1
2 OpenLogicalChannel OpenLogicalChannelAck
. 2.14.
openLogicalChannel ,
,
. ,
, , Uni-directional Logical Signalling. , ,
directional
Logical
, .
Bi-
Signalling,
Uni-directional
Logical
openLogicalChannel
Signalling openLogicalChannelAck.
– openLogicalChannelConfirm, – ,
openLogicalChannelAck (
. 2.15). 1
2 OpenLogicalChannel
OpenLogicalChannelAck OpenLogicalChannelConfirm
. 2.15.
CloseLogicalChannel,
, ,
, ,
. endSessionCommand. , 2.3.
H.245.
c 39
2.3.1.
?
2.3.2.
IP-
2.3.3.
?
?
2.3.4.
H.323
?
2.3.5.
RAS?
2.3.6.
ARQ
RAS?
2.3.7.
ARJ
2.3.8.
RAS?
.225?
2.3.10.
H.225 Setup?
2.3.11.
H.225 Alerting
?
2.3.12.
H.245?
2.3.13. H.245? 2.3.14.
H.245 TerminalCapabilitySet?
2.4. №1 .323,
:
1 2 3
,
,
,
. №2 IPRAS. 1)
–
2)
–
3)
–
40
№3 .225.0. 1) 2)
№4 IP.245.
41
3.
IP-
SIP
3.1. SIP, MMUSIC (Multiparty Multimedia Session Control)
IETF (Internet Engineering
Task Force),
RFC 2543 –
Session Initiation Protocol (SIP) ,
:
, .
SIP (Session Initiation Protocol)
,
:
, . . . ,
.
, ,
.
– REGISTER – . ,
, .
,
SIP,
.
. И
И
,
SIP
IETF. ,
Internet Engineering Task Force (IETF). .
SIP
.323. SIP
– DSS1
7.
SIP . .25, Frame Relay, AAL5, IPX
.
SIP
. IP
UDP. 42
, UDP, ,
.
SIP
. 5.1
TCP/IP. IP
:
,
,
,
. , (
),
.
, ,
SIP . – SDP (Session Description Protocol).
, SDP
SIP
.
( SIP) TCP
UDP
IPv 4
IPv 6
PPP, AAL5 ATM, Ethernet, V.34.
. 3.1.
SIP
TCP/IP
IETF RTP,
SIP .
3.2. - ,
. URL (
SIP URL).
SIP
SIP
–
.
, . : «
», «№
@
», «
@
», «
@IP-
». .
,
@
.
–
, alias-
;
, 43
IP-
, IP-
DNS. ,
, . –
.
, . SIP
’sip:’,
(
,
SIP-
,
, ‘mailto’).
SIP-
( ,
. .).
, .
'
'
', '
'
',
. SIP-
.
URL
,
,
Web-
: sip: [email protected] sip: user1@ 195.201.37.104 sip: [email protected] 3.3. Э
SIP-
SIP
: (User Agent
SIP client) –
(User Agent Client – UAC)
(User Agent Server
– UAS),
.
UAC
, . .
.
SIPUAS
, . .
. ,
.
: -
-
(proxy server)
,
, UAS.
,
–
-
, ,
‘
'
‘
’.
UAC. (stateful)
UAC, -
:
(stateless). , 44
.Э
. ,
. .
. ,
.
,
, , .
-
,
.
,
-
,
«
»
,
.
,
,
,
. (redirect server) , .
. Contact
SIP.
, . ,
-
. (location server). Э
SIP-
SIP
–
,
, . RFC 2543, ,
2167)
: LDAP (RFC 1777), rwnois (RFC
. ,
'
.
,
SIP
,
, .
, ,
'
. SIP-
REGISTER. (
SIP. 3.2),
,
.
45
-
SIP
SIP
SIP
SIP
SIP
. 3.2. 3.4.
SIP-
SIP . «
-
»
,
,
.
,
, ,
, .Э
, SIP-
.
,
. SIP (
),
, RFC 2279.
SIP (
. 3.3)
.
46
. 3.3.
SIP
SIP,
. ,
.
, ,
,
. , .,
,
,
,
.
.
( . .
), ,
. SIP
ACK, INVITE ,
.
OPTIONS
,
SDP.
,
BYE
REGISTER
.
:
, .
, . Э
, ,
,
,
,
. .
,
. ,
–
.
:
(
); 47
(
‘Content’ ,
);
(
);
(
). , ,
(:)
,
, : .
Call-ID – ;
(call reference)
,
.
,
DSS-1.
-
@:
[email protected] To
;
–
SIP-
,
'tag'
,
SIP URL. ,
,
,
:
the director tag=12345. ;
From –
.
CSeq –
Call-ID,
,
,
, ;
1
:
2^32
. -
Via –
,
,
UAS.
;
,
,
Via
. Э
, . . ,
,
, (
,
firewall). – sip.telecom.com,
niits.ru,
: Via: SIP/2.0/UDP sip.telecom.com:5060 Via: SIP/2.0/UDP niits.ru:5060 .
Content-Type – ,
:
SDP
, . 48
.
Content-Length – З SIP
. ,
SIP,
, ,
. ,
,
,
. .
,
.
SIP-
Request-URI
.
. INVITE –
. ,
(
),
,
, .
INVITE
,
, ,
(
. 3.4).
INVITE sip: [email protected] SIP/2.0 Via: SIP/2.0/UDP kton.bell-tel.com From: A. Bell To: T. Watson Call-ID: [email protected] Cseq: 1 INVITE Content-Type: application/sdp Content-Length: ... v=0 o=bell 53655765 2353687637 IN IP4 128.3.4.5 SIP=IN IP4 kton.bell-tel.com m=audio 3456 RTP/AVP 0 3 4 5
. 3.4 Э
SIP-
[email protected]
[email protected].
, 3456
(G.723)
,
5 (DV14).
From
0 (PCMU), 3 (GSM), 4 -
(< >)
boston.bell-tel.com. ,
49
. ACK –
INVITE .
OPTIONS – . . BYE – .
, ,
.
CANCEL – , 2
( . .
,3 ,4 ,5 ,6 )
.
REGISTER – SIP.
О ,
(
.
-
)
:
,
,
. .
SIP
.
,
.
3-
.
,
,
. ,
,
. :
.
,
.
3-
,
2, 3, 4, 5
6:
, .
1
–(
2
–(
3
–(
:
)– )–
,
, ,
; ;
)– ;
4
–(
)–
;
5
–(
)–
;
6
–(
)–
. 50
. 3.5. SIP/2.0 200 OK Via: SIP/2.0/UDP kton.bell-tel.com From: A. Bell To: ; Call-ID: [email protected] Cseq: 1 INVITE Content-Type: application/sdp Content-Length: ... v=0 o=watson 4858949 4858949 IN IP4 192.1.2.3 t=3149329600 0 SIP=IN IP4 boston.bell-tel.com m=audio 5004 RTP/AVP 0 3 a=rtpmap:0 PCMU/8000 a=rtpmap:3 GSM/8000 . 3.5.
SIP-
Watson
Bell
5004, .
Call-ID
, PCMU, GSM.
,
Cseq
–
From, To, Via, INVITE Cseq: 1.
3.5. SIP
(
UAS),
-
. ,
SIP-
'user@domain',
. IP-
DNS.
. , , .
,
,
,
-
.
,
.
я
я .
INVITE (1) 5060,
(
. 3.6). .
2, 3. temporarily
302 Moved
4, 51
, . 302
ACK 5. .
INVITE 6.
INVITE SDP. INVITE
,
100 Trying 7 . , 180 Ringing 8. 200
9,
SDP.
10.
, . BYE 11, 200
1. INVITE
12.
2. 3.
4. 302 Moved Temporarily 5. ACK 6. INVITE 7. 100 Trying 8. 180 Ringing 9. 200 OK 10. ACK
11. BYE 12. 200 OK
. 3.6.
я
я
52
,
1,2,3 .
(
)
-
INVITE 4 (
.4.7). ,
5;
,
200
-
-
6.
7, ,
8,
9.
, ,
200
.
BYE 10,
11. -
1. INVITE
2. 3.
4. INVITE 5. 180 Ringing
5. 180 Ringing
6. 200 OK 6. 200 OK 7. ACK 7. ACK
8. BYE
8. BYE 9. 200 OK
9. 200 OK
. 3.7.
-
3.6. 1.
SIP?
2.
,
SIP,
? 3.
SIP
TCP/IP.
4. ? 5. 6.
SIPЭ
SIP-
.
.
. 53
7. 8.
. -
.
.
-
9.
,
.
.
10.
.
11.
SIP-
.
.
12.
SIP.
13.
SIP-
14.
«
, -
15.
? ».
SIP.
?
16.
?
17.
SIP.
18.
SIP.
19.
.
20.
21.
-
22.
?
23. ? ? 24. ? 25.
(
.8.2), ?
3.7. №1 SIP-
.
№2 I : Director SIP: [email protected] : engineer SIP: [email protected]
II : Andrew SIP: [email protected] m : Sasha SIP: [email protected]
III : Bill Gaits SIP: [email protected]
3.1 IV : User A SIP: [email protected]
: V. Ivanov SIP: [email protected]
: User B SIP: [email protected]
54
niits.ru sip.niits.ru
c
Sipserver.com central.com bell.org BYE, 302 Moved Temporarily
INVITE, 200 OK
microsoft.com interconnect.com telecom.ru OPTION 404 Not Found
(
. 3.1).
. 3.1, . 3.6
,
bonch.edu centralserver.ru REGISTER 200 OK
, ,
3.7.
№3 . 3.2. 3.2 I . → PS→ RS → PS → . : . ( )–
II
. → RS → PS → RS → . ( ), PS –
III
. → PS→ PS →RS → . -
IV
. → RS → PS → PS → .
, RS –
55
4. 4.1. IP.
H.323, SIP,
. –
,
IP-
.
, ,
–
Media
Gateway Control
Protocol
IETF.
(MGCP), SGCP –
Simple Gateway Control Protocol (
) –
Telcordia (
Bellcore).
Level 3
, IP, – IDCP (IP Device Control Protocol). MGCP.
IETF,
ITU-T (
16)
H.248/MEGACO, MGCP. IETF MEGACO
ITU- T SG 16
SGCP
IPDC
MGCP
MDCP
MEGACO
H.GCP H.248
. 4.1.
:
•
– Media Gateway, , ,
,
IP: RTP/UDP/IP,
; 56
•
– Media Gateway Controller, ; MGC
•
MGCP Softswitch;
– Signaling Gateway, ,
, . Media Gateway Controller
Signaling Gateway
SS7
Analog Line
Media Gateway
MGCP/H.248/MEGACO
TDM Media Gateway
Media Gateway
RTP
PBX
. 4.2.
, , .
STP – – ,
7
CAS-
.
(CAS), , .
. .
. , ,
.
MEGACO ,
,
MGCP, H.323, SIP
4.2.
ISUP/IP.
MGCP MGCP . IP
.
,
IETF, 57
. ,
,
,
.
. – MEGACO/H.248. 4.3.
MEGACO/H.248
MEGACO
IETF
,
MGCP.
MEGACO :
(context),
(termination) .
. 4.3. Media Gateway
Context
Termination SCN Bearer Channel
Termination
Termination SCN Bearer Channel
RTP Stream
Null Context
Context Termination
Termination SCN Bearer Channel
RTP Stream
Context Termination
Termination SCN Bearer Channel
RTP Stream
. 4.3. 4.3.1.
(Terminations) (
)
-
.
. 58
,
. ,
, , ,
.
,
, IP
(
, RTP-
),
.
Add
Subtract, Add
Subtract,
, . (TerminationID),
. MG,
,
E1
. ,
(TerminationID) –
«Root».
wildcard: ALL
CHOOSE. ,
. (properties), (propertyID).
, ,
,
DTMF. . MEGACO
.
, . , .
.
,
,
«
»
. ,
,
,
,
. ,
MG . 59
. 4.3.2.
(Context)
К
–
, (
)
/
. ,
. –
,
.
,
,
.
(
,
) . Add.
,
, ,
. Subtract. Move. ,
,
.
-
,
. :
•
– ContextID.
•
( ). , . .
,
-
,
•
,
, . 16
•
,
15- . «
» . ,
. .
4.4.
H.248/MEGACO 60
4.4.1. ,
,
.
H.248
,
.
. .
, .
: = {
=
,
…}. , . 4.1. 4.1
Modem Mux
, , H.221, H.223, H.225.0
, Media TerminationState
. .
ServiceStates
( – out of service, - in
- test, , BufferedEventProcessingMode
service). ,
: Stream
. . (Remote, Local, LocalControl, Signals,
Events), Local
,
, .
, .
.
, .
, Remote
,
,
, LocalControl
Mode – Mode inactive, loop-back
Events
. send-only, receive-only, send/receive,
delete. . ,
.
, NotifyAction
:
), Accumulate ( AccumulateByDigitMap ( ), KeepActive ( ).
( ),
,
Signals
, .
Audit
(
), .
AuditValue
AuditCapabilities.
61
Packages DigitMap
,
ServiceChange
AuditValue
,
,
,
.
ObservedEvents
. Notify
AuditValue.
Statistics
, .
Extension
,
, , ( . .
). ,
–
«
,
»,
,
. 4.4.2. –
. .
,
Notify
ServiceChange.
. 4.2 K Add (
MGC → MG
)
Modify ( ) Subtract ( ) Move ( ) AuditValue (
MGC → MG
MGC → MG
MGC → MG )
MGC → MG
K . K . K
.
K . K
, , ,
, AuditCapabilities ( )
Notify ( ) ServiceChange ( )
MGC → MG
. K ,
, ,
MG → MGG
, ,
.
MGC → MG, MG → MGG
. , . K .
62
4.4.3. ,
MGC
MG
,
TransactionID, .
. ,
(
)
, .
,
. TRANSACTIONx CTXTID1
CTXTID2
CTXTID3
COMMAND1
COMMAND2
COMMAND3
COMMAND4
COMMAND1
COMMAND1
COMMAND2
COMMAND3
. 4.4. 4.4.4. . ,
.
(Message Identifier – MID) (
/
/
)
. H.248 –
,
, .
,
, ,
. 4.5.
63
Megaco/H.248 message
Transaction . . . Reg or Reply
Transaction Reg or Reply
Header
Trans Hdr
Ctx Hdr Command
Action . . .
Ctx Properties
Cmd Hdr
Transaction Reg or Reply
Action
Command . . .
Descriptor . . .
Command
Descriptor
. 4.5. 4.4.5.
H.248/MEGACO
(Packages) , . ,
,
, MG
«
»
«
.
MGC,
Packages,
».
,
,
. –
,
,
,
.
,
,
, ,
,
. ,
,
, MG ,
,
. .
4.5. MEGACO/H.248, , .
.
–
, 64
1-2
, . . IP-
1-2
. .
– IP, . .
,
,
. IP,
. Ш MG1
Ш MG2
MGC
Service Change Modify
Service Change Modify
"
"
Notify Modify
Notify Add, Add "
"
Add, Add
Modify
Modify
"
"
Notify Modify, Modify
Modify
AuditValue Requested Info
Subtract Subtract
Notify Subtract Subtract
4.6. MEGACO 1)
MG1
MGC
ServiceChange. 2)
, ServiceChange.
3)
,
,
, 65
«
».
Modify (
),
,
.
–
(SendReceive). 4)
MG1
Modify.
5)
(
6)
1 – 4)
MG1
MG2.
,
A
,
Media Gateway Controller
Notify.
7)
Notify.
8)
MGC,
Modify .
, «
9)
».
Modify.
10)
MG1, Notify.
11)
.
12)
MGC
,
MG1,
,
MG2,
. MG1
Add
(
)–
(RTP-
,
). ,
MG2 (
IP-
, RTP-
MG1 ,
MGC
),
MGC
(
ReceiveOnly).
Add .
13)
MG1
(RTP.
)
,
,
, .
14)
MGC
Add
MG2 (
SendReceive)
.
66
15)
, UDP/RTP
MG2
.
,
RTP-
Megaco/H.248, 16)
,
.
Modify
MG1 «
17)
(
)».
MG1 .
18)
MGC
MG2 .
19)
MG2
«
»
. 20)
, ,
,
MG2
,
, . 21)
MG2
,
,
MGC
Notify.
22)
Notify.
23)
MGC
Modify
MG2
. 24) 25)
MG2
.
,
Modify
MG1
(
SendReceive), «
26)
,
MG1
».
.
27)
, . RTP-
28)
MG2,
MG2
MGC AuditValue.
.
AuditValue
,
,
. 29)
, MGC
30)
MGC
MG2
Notify. Notify.
67
31)
, ,
MGC
.
Subtract. 32)
Subtract MG1
,
MG2,
,
.
, . 4.6. 1) 2) 3) 4) 5) 6)
MGCP MEGACO MEGACO? . MEGACO
MGCP?
MEGACO? 7) 8) 9) 10) 11) 12)
?
? ? LocalControl?
Add. MEGACO » MEGACO?
«
4.7. №1 MEGACO . 4.5.
, ,
,
7?
68
5. 5.1.
I -
«
». ,
Linux,
,
.
.
5 .
«
-ITG».
. 5.1.1. -ITG (
. 5.1) -
, IP.
, ,
,
IP.
. 5.1.
-ITG
( IP-
-
) .
69
IP ITU-T H.323 v2,
:
-
RTP/UDP/IP;
-
E-DSS1
(ISUP-R –
)
-7
H.323 ITU-T H.246;
-
DTMF;
.
Web-
(Web-
).
IPIP-
. .323
(Cisco)
(Microsoft Netmeeting 3.0).
(
. 5.2)
(64
: (Celeron 500 MHz)
); -
(10
),
-
, HDLC
-
;
(
-
);
-
-
-
;
(2),
-
;
,
7 . (
.5.1)
: -
;
-
Web-
(
–
); -
,
.
5.1 70
: -
Red Hat Linux 6.2 telnet :
-
(DSS1, SS7), H.323, , 7
(
, E- DSS1)
IP1 10/ 100 BaseT
2
. 5.2.
«
-ITG»
, / IP.
: (G.711, G.723.1, G.726,
G.728, G.729),
, .
, DTMF,
. ИК
G.703
1.
,
71
(Celeron, 500 (10
),
(64
),
,
)
. , .
1
.
IP-
2 . .
IP ITU-T H.323 v2,
:
-
RTP/UDP/IP;
-
E-DSS1
№7 (ISUP-R –
)
H.323 ITU-T H.246;
-
DTMF;
.
IPIP-
. .323
(Cisco)
(Microsoft Netmeeting 3.0). . 5.2. 5.2 1
2 2
.
:
-
,
/ 120
, ,
/
,
1 , 120
(
ITU-T
G.703) 2048±0,1 HDB3 3±0,3 244±25 30x64 (PRI) Ethernet 10/100 BaseT
IP TCP/IP, RTP/RTCP, UDP H.323 v2, H.225 (RAS, Q.921), H.245; DSS1 (Q.921, Q.931); -7( ISUP-R, MTP) G.711, G.723.1, G729 : -
, ,
60 ± 6 50 ± 2,5 telnet
. 5.3. 72
5.3 Celeron, 500 MHz 10 64
, ,
-
. 5.4. 5.4
-
-30
, ,
2048 HDB3 G.703(
,
/ )
-ITG PRI (
1
ITU-T- I.431
300 011)
DSS1 ( ITU-T-
Q.921,
ETSI ETS 2
3
ITU-T-
№7 (ISUP).
Q.931)
IP
Ethernet 10/100BaseT. 5.1.2. , . .
1.
«
-ITG».
2.
,
3.
,
. IP-
? 4.
( IP-
5.
)? .
6.
.
5.2. 5.2.1. . 5.3
73
1 -ITG
1
2 -ITG
Setup Call proceeding
Setup
Setup Call proceeding Alerting
Call proceeding Alerting Alerting
Connect Connect ACK
Connect
Connect
2
TCS
TCS
Connect ACK TCSAck
TCSAck
MSD
MSD
MSDAck
MSDAck
OLC
OLC
OLCAck
OLCAck
Disconnect EndSessionCommand Release
Disconnect
EndSessionCommand
Release Complete
Release Release Complete Release Complete
H.245
. 5.3.
1
Q.931 Setup
1, .
1
Setup,
,
Called Party Number.
callroute.cfg ( IP-
.
2
IP-
permissions.cfg. ,
.
3),
, ,
,
2.
Q.931
(
(
), H.225 Setup
)
Q.931 Setup Setup
Call Proceeding. 74
, Q.931 Alerting.
2
1
2
H.225 Alerting
1.
Q.931 Alerting, (
).
2
2
Q.931 Connect.
Q.931 Connect H.225 Connect
Q.931 Connect ACK.
2
1
.245,
.
Q.931 Connect
1
1. .245,
TCP-
,
.245. H.245 . TerminalCapabilitySet, .
,
TerminalCapabilitySet
,
.
TerminalCapabilitySet
,
,
TerminalCapabilitySetAck. /
,
, , ,
, . masterSlaveDetermination. masterSlaveDetermination ,
masterSlaveDeterminationAck, ,
–
.
. –
( ) openLogicalChannel
, .
, openLogicalChannel ,
openLogicalChannelAck, RTP
,
RTCP.
75
. ,
RTP/UDP/IP,
RTP-
, RTP. RTP
RTCP
. .
,
,
, H.245 endSessionCommand, . , ,
, endSessionCommand .245 . Release Complete,
,
. ,
endSessionCommand
,
,
, ,
,
endSessionCommand. , Release Complete, .
[1, 6]. 5.2.2. . . 1. 2. 3. 4.
.323. .323. Э .323: .323:
IPIP.225.0 ( H.245 (
, ,
.323 .323 ) )
76
5.3. 5.3.1. 1 -ITG
1 Setup Call proceeding
2 -ITG
2
ARQ ACF Setup Call proceeding
ARQ ACF
Setup Call proceeding Alerting
Alerting Alerting
Connect
Connect
Connect ACK
Connect TCS
TCS Connect ACK TCSAck
TCSAck
MSD
MSD
MSDAck
MSDAck
OLC
OLC OLCAck
OLCAck
Disconnect Release
EndSessionCommand EndSessionCommand Disconnect
Release Complete Release Complete
DRQ
Release
DRQ
DCF
DCF Release Complete
H.245
. 5.4.
77
.5.3, . RAS.
Q.931 Setup
RAS (
(
1
. 6.4)
ARQ).
, ACF. .225 Setup. DRQ
,
DCF. 5.3.2. .
.
1.
?
2.
?
3.
RAS?
4.
ARQ
5.4.
ACF, DRQ
DCF?
Linux
5.4.1. Linux –
Unix – . Э X Window System.
Linux
Internet Unix, DOS, MS Windows.
,
, .
Linux
Intel PC 386/486/Pentium/Pentium Pro.
Linux
Internet, p
p ,
,
. .
telnet. . MICROSOFT® 78
WINDOWS
,
telnet (
telnet). PuTTY (
. 5.5).
. 5.5.
PuTTY «
-ITG» (
). Stored Sessions. (
. 5.6).
Linux, .
. 5.6.
Linux,
«
-ITG». 79
.
, Linux (
. 5.7).
. 5.7. Midnight Commander, .
( Norton Commander
. 5.8).
DOS ( ,
).
⇐,⇑,⇒,⇓,PageUp, PageDown, Home, End.
,
Enter. , F4
F3, -
–
F4. .
80
. 5.8.
Midnight Commander
5.4.2. Linux. .
1.
?
2. 3. 4.
? telnet? Midnight Commander?
? ,
. 5.5. 5.5.1. , . , «
»:
common.cfg • DSS1.cfg
• physical.cfg • protei.cfg • SS7.cfg
81
, :
• gateway.cfg (
)
• callroute.cfg (
)
• permissions.cfg (
IP)
• H323.cfg (
.225
.245
-
, H323).
.
«#» ,
. –
gateway.cfg
(General) –
,
: - Name –
(
),
«alias»
H.323;
- IP-IP –
(
).
,
; - Port –
TCP,
IP-
(
1720);
- Prefixes –
, (
-
– 812),
(
–
- MaxCall –
);
,
(Audio) –
; .Э
,
,
: - SilenceSupression – «
»
.
«
»(
(0/1) –
:
– 1);
- Codecs – (g729/ g723/ g711/ gsm) – (
– g729,g711).
g729. (Gatekeeper) –
,
: - UseGatekeeper – (0/1) –
(
– 0); - AutomaticGatekeeperDiscovery – (0/1) – (
– 1). : 82
-
IP – IP-
(
-
Port – UDP
– 0.0.0.0)
,
RAS-
(
1719). –
callroute.cfg H.323 .
–
,
–
,
. , IP-
. –
(0..9).
,
–
*. IP-
–
permissions.cfg
(
) IP-
,
. - AccessRule –
IP.
GeneralRule
: GeneralRule = ALLOWED/DENIED – .
- ExceptList – . IP-
,
,
/,
, .225
, .
.245
, H323 –
H323.cfg
. H.225
:
- FastStart –
(0/1) – «
Fast Connect (
»
«
»
– 0);
- MediaWaitForConnect – »
(0/1) – «
»
«
Connect (
–
0). H.245
:
- H245Tunneling –
(0/1) – «
» H.225 (
»
«
H.245 – 1);
83
- EarlyH245 –
(0/1) – «
»
H.245
«
»
, . . Connect (
– 0). (Audio) -
-
. -
:
- AdaptiveJitter –
(0/1) – «
»
jitter-
»
«
(
– 0); - InitialJitter –
jitter-
(
– 60). -
.
G.711: - PacketizationIntrerval – (
– 30).
G.723.1: - PacketizationIntrerval – ,
30
). (
(
G.723.1 – 30
– 30); - Rate –
. 0 – 6.3
5.3
/ .(
/ , 1 –
– 0).
G.729: - PacketizationIntrerval – . (
10
(
G.729 – 10
)
– 30).
Gateway.cfg # general gateway parameters [General] Name=Niits IP=192.168.100.4 Port=1720 Prefixes=7812 MaxCalls=5 # gatekeeper parameters [Gatekeeper] UseGatekeeper=1 # Gatekeeper discovery method # 0 – manual discovery # 1 – automatic discovery 84
AutomaticGatekeeperDiscovery=0 #manually set gatekeeper address IP=192.168.100.21 Port=1719 #Audio parameters [Audio] SilenceSuppression=1 Codecs=g729,g723 Callroute.cfg [CallRouting] # prefix gateway 7095* 195.239.254.13 # Moscow /Teleross Permissions.cfg [AccessRule] GeneralRule = DENY [ExceptList] 194.85.131.3/32 # from Moscow 195.205.33.11/32 # from Arkhangelsk 195.205.35.24/32 # from Severodvinsk 192.168.100.0/24 # from our subnet H323.cfg #Protocol options [H.225] FastStart=1 MediaWaitForConnect=1 [H.245] H245Tunneling=1 EarlyH245=0 #Speech processing parameters [Audio] AdaptiveJitter=0 InitialJitter=60 #60 ms [G.711] PacketizationIntrerval=30 #30 ms [G.729] PacketizationIntrerval=30 #3 frames, 10 ms per frame [G.723.1] PacketizationIntrerval=30 #1 frame, 30 ms per frame # Speech rate: # 0 – low-rate speech (5.3 kb/s) # 1 – high-rate speech (6.3 kb/s) Rate=1
85
5.5.2. . , : 1.
IP-
2.
: 192.168.100.104
IP-
:192.168.100.104
192.168.100.22 3.
,
10
192.168.100.104,
20
21 –
4.
11,
IP-
IP-
192.168.100.22
G.711
5.
FastStart (
6.
IP-
. [1]). 192.168.100.25 .
1.
«
2.
?
3.
.
4.
?
5. 6. 7.
-ITG»?
? IP-
? ,
?
86
1.
. ., c
. .,
. . IP-
.
.:
, 2005.
2. ITU-T Recommendation H.225.0. Call signaling protocols and media stream packetization for packet-based multimedia communication systems. – Geneva, 1998. 3. ITU-T Recommendation H.245. Control protocol for multimedia communication. – Geneva, 1998. 4. ITU-T Recommendation H.323. Packet based multimedia communication systems. – Geneva, 1998. 5. RFC 2543. SIP: Session Initiation Protocol. M. Handley, March 1999. 6.
. .,
. . Softswitch.
:
, 2006.
87