???????? ?????? ? ????? ????? Internet

1
???????? ?????? ? ????? ????? Internet
2

• ??????????? ? ???? IP-?????????
• ???????? ?????????????? ?????????? ?????
• ???????? ???????????????? ???????? ?????? ? ?????
• ?????? ???????? ? ????? ?????????? ??????
  IP-?????????
• ?????? G.711, G.723, G.729 ? ???? DSP
• ????????? ???????? ????????? ?????? RTP ? RTCP
• ????????? H.323 ??? ?????? ??????????????
  Internet-??????
• Terminals, gateways, gatekeepers - ????????
  ??????? H.323
• ????????? ? ???????? IP-?????????
• ??????????? ?????????? ???????????? ? ???????
  ????????? RAS
• ??????? ???????????? ?????????? ? ???????
  ?????????? H.225.0 ? H.245
•  

3
?????????????? ??????????? (Soft switches) ??
?????? ?????????? MGCP ? Megaco/H.248 ???????????
????? SIP ????????, ??????-??????, ??????
?????????????, ?????? ??????????? ??????????????
????????????? ???????????? ?????????????? ??????
? ??????? ?????????? SIP ? SDP  ????????? ??????
IP-?????????, ??????????? ?? ?????? H.323 ?
SIP ?????????? ??????? E.164 ? DNS-????? ?
??????? ????? ENUM ?????????? ??????
IP-????????? ?????????? ?????????? ????????????
SS7 ? SIP, ???????? SS7 ?? SCTP ????????????????
?????????? ???? IN ? ?? ?????????? ? IP-??????
4
??????????? IP-?????????, Internet-?????????,
Voice over IP (VoIP)
??????????? ?????? ITU World Telecommunication
Policy Forum (WTPF 2001, 7-9 March 2001),
????????? ???????????? IP-?????????
IP-????????? - ??? ????? ??????, ????????????
???????? ?????? ? ????? (? ????? ????????? ?
???? ???????) ???????? ??? ????????? ?????
???????? ???? ?? ?????? ????????? IP. ???????
IP-????????? ???????????????? ????? ? ?? ??
??????, ????? ????? ? ???? ?????????? ?????? ?
??????? ?????? ??????????, ? ????????? ? ???????
? ????????????. VoIP - ??????? ???????
IP-????????? Internet-????????? - ????? ?????
??????, ??????????????? ??????, ????? ??????
IP-????????? ???????? ??? ?????????
?????????????? ????? Internet.
Voice is easy, telephony is hard Nortel
5
???????? ??????????? IP ????????? ?????? ETSI
TIPHON(Telecommunication and Internet Protocol
Harmonization over Networks, ???????? ? 1997 ?.)

•     ??????????? ???????????????????? ???????
  ?????? ????? ?????? ???????????? ?? ???????, ? ??
  ?? ??????????? - ??????? ???? ??????????? ?
  ?????? ????????????? - ?????? ? ?????????
  ?????????????, ? ??? ???????????? ?? ?????
  ????????, ?? ?????? ????? ?????????? ???????????
  ??????????????? ??? ??????.
•       ????? ????????? ?????????????? ????? ?????
  ??????? IP-???? ? Internet -??????? ?????
  ????????? Internet ? ??????? IP-????? ????????
  ?????????? ????????
•    ??? ???????? ????????????? ??? ???????,
  ?????? ????????????? ???????? ? ??????????
  ????????. ???????? ?? ??, ??? TIPHON ???????, ???
  ?????????? ??? ????????? ??????, ?????????
  ???????????? ??? ? ?????? ?????? ??? ?? ??????.
  

6
??????????? TIPHON
Voice over IP ????? ?????? ??? ?????? ???????,
??????????? ????? ? ????????????? ??? ?????
IP-???? ? ????? Internet ??? ??????? ????.
IP-????????? ??? ?????? ?????????, ?? ????
??????, ?????????????? ????????????? ?????????
?????????? ??????????????? ?? ?????
????-??-??????, ??????? ?????????????? ?????,
???????????? ????????? IP ? ????? ??????????????
Internet ??? ??????? IP-????
7

• Public Telephony - ??????, ??????????????
  ????????????? ????????? ??????????
  ??????????????? ?? ????? ????-??-??????, ???????
  ?????????? ????????? E.164
• 371 776 13 80
• ??? ?????????? ??????? ???????? ?????????????
  ???????? ?????????? ???? ?????? ???????????, ????
• (Public Switched Telephony Network, PSTN ?????
  ????? ??????)
• Internet Telephony - ??????, ??????????????
  ????????????? ????????? ??????????
  ??????????????? ?? ????? ????-??-??????, ???????
  ?????????? ???????? ????? Internet
• robert_at_ibm.com

8
????????? E.164 ? ?????????? ISO-7498
AFI(Authority and Format Inentifier) Initial Domain (?? 15 ????) Part DSP(?? 40 ????)
E.164X.25PSTNGeographicalIntern. Org Country 44 Sity 207 Number 333-44-55 Extensions 567
9
???? IP-?????????

• ???????? ????????????? (??? ??????????) ?
  ????????? (??? ????????????) ????????????? ?
  ????????????? ??????? (??????????? ????)
• IP-?????????????? ??????? PSTN
• ????????? ??????? ????? ????? ???????? ????????
  ???????? ?????????????? PSTN ? ?????????? ?
  ????????????? ???????????
• ???????? ?????? ??????? ??? ????????? ????????
• ???????? ????? ????? ?? ???? ?????????? ?????????
  ? ????????? ??????(?????????????? ????)

10
???????? ????????? ??????? ?????
???
???
????????? IP-tel ???????
????????? IP-tel??????
Internet
????? ?? ??????????
????????????? ???????

• ??? ??????????? ??????????
• ????? ???????????? ? ???
• ????? ????????? ??????? ? Internet-???????????
• ????? ????????? ???????? ? ???????
  IPtel-???????????? (IPTP)

????? ? IP ???????
11
????? ??????
?????? ?????? ??????????? ????? ??? ????????
(Internet Call Waiting)
??????
?????????? ? Internet
?????????????????
????
?????? ?????????? ???????
???? IP-?????????
Internet
??????????? ?????? ?? IP-????????? ????? Internet
? ??? ???? ????????? ??????? ??????????
IP-?????????
12
???????? ???????? ?????? ? ????????
?????????-????????? (??? ????????????? ????
????)
????????
???
?????????? ??????? ??????????
???????????
1. Setup bob.att.com
3. ????? DNS - 192.100.15.106
2.?????? DNS - bob.att.com
4. Setup 192.100.15.105
6. Open channel RTP
7. Ack open channel RTP
8. ???? ? ??????? RTP
4. Setup 192.100.15.105
5. Connect 192.100.15.105
?????????? ? ????????????
????????, ????????
???
???????????? ??????? ??????????
?????????????
7. Ack open channel RTP
4. Setup 192.100.15.105
6. Open channel RTP
IP
5. Connect 192.100.15.105
8. ???? ? ??????? RTP
????????
???
?????????? ??????? ??????????
???????????
8. ???? ? ??????? RTP
4. Setup 192.100.15.105
6. Open channel RTP
?????????? ? ????????????
5. Connect 192.100.15.105
7. Ack open channel RTP
????????, ????????
???
???????????? ??????? ??????????
?????????????
13
IP-????????? ? ????????? ? ??????????
????????????
Branch Office
Analog Voice
VoIP Gateway Resident side
Gatekeeper Connection Management
Digital IP Voice
IP
PBX or KTS
Fax
VoIP Gateway Trunk side
Digital Voice
Analog Voice
Headquarters
14
????? ? ????? ???????? IP-?????????
1-? ???????? ????????????? ???? ???????????
????????? (IP ??? PSTN) ? ??????? ?????????? ????
?????? ?????????? 2-? ???????? ?????????????
????????? ?????? (??? ?????? ????? ?
?????????) 2-? ???????? ?????????????
????????????? ??? ???????? ????????
15
????? ? ??????????? ?? ???? ??????????? ?????????
? ?????????? ????
1. IP IP ??? ????????????? ???? PSTN (???????)
NGN ? IP ???????????
???
???
??????? IP-tel ?????????? ????? - IPTP
IP phone
IP phone
16
2. IP IP c ????????????? ????? PSTN
????????????? ????????, ???????????? IP PBX, ??
?? ??????? ??????? IP ????, ?????????????? ??????
??????? QoS
IP PBX - Softswitch
ITG
PSTN
IP-telephony
?????? ???????? ????????? E.164 ????? ???????
??????????? E.164 lt-gt DNS
17
3. PBX IP Private PBX ?????????????
IP-????????? ?. ????????????? ???? ??? VoIP


18
B. ????????????? ???? ? ???????? PBX ? ???????
ITG ??????????? ????? ??????? ???? IP ? ??????
??????? QoS
Branch Office
Headquarters
PBX
IP Phone
IP Router
IP Router
IP WAN
IP Phone
IP Tel Gateway
IP Tel Gateway
Gatekeeper
Branch Office
PBX
IP Router
PBX
IP Phone
IP Tel Gateway
19
IP ???????? ??????-?????????? IP-????????????????
???????? ??????, ???? ? ???????
??????????????? ??????
????????
????
???????
IP Telephony Gateway
PSTN
IP Telephony Gateway
TraditionalPhone
Automated Agents
Switch
Customer Information
Router
Router
Voice Fax Mail
IP TelephonyGateway
Management Systems
Video
Internet
Data
IP Telephony Gateway
IP Telephony Gateway
Web
E-Commerce
E-mail
?????? ???? ??????????? ??????!
20
4. Phone-PSTN-IP-PSTN-Phone IP Telephony ???
?????????? - ???????
???? IPTP
???? IPTP
???? IPTP
21
5. IP Phone c ?????????????? ?????? IP ?
PSTN ?) ????????? ?????????? IP-??????? -gt
?????? ?? ????? 2
IP
ITG
PSTN
Softswitch
IP-telephony
?? ????? ????? ??????????? ?????? ??????????
Net2Phone ? DotDialer
?????? ???????? ????????? E.164 C??????
??????????? E.164 lt-gt DNS ?
22
5. IP Phone c ?????????????? ?????? IP ?
PSTN B) ????????? ?????????? Phone
IP
ITG
PSTN
Softswitch
IP-telephony
?????? ???????? ????????? DNS C??????
??????????? E.164 lt-gt DNS ?
23
????????? ????? ???? ???????? ??????

• ??????????? ?????????
• WAN
• ??????????? ??????
• ??????????????? ??????
• ?????????? ????????
• LAN
• ??????????????? ??????
• ????????? ? ?????????? ??????
• ?????????? ????????
• ??????????
• ??????????????? ??????? ?????????????
• ??????????????? ??????-??????????
• ??????????????? ?????????? (directory, policy)

ATM Frame Relay IP
W A N
L A N
A P P S
24
???????????? IP-?????????
??????????????
???????????????
Voice Mail
Fax
Private IP networkInternet
Private IP network (Internet)
E-mail
????? ??????????
Toll Bypass Consolidation
Unified Messaging
E-Commerce
??????-??????????
????????
25
????? ???????? IP-?????????
gt2002
lt1998
?????????? ??????
IP-?????????
????????? ? ??????????? ???????
????????? ????????-????????? ????????
PBX Apps
Distributed Gatekeeper
Dist. Apps Svrs
KS Apps
Apps
IP Phones
KS
PSTN
PBX
Unified Mgmt Directory Policy
VoIP
IP Appliances
QoS
QoS
IP LAN/WAN
IP LAN/WAN
Integrated Management Directories
Legacy Access Modules
ATM/FR
Call Svr, Apps Svr Router, Mgmt Svcs Directory
Svcs Policy Svcs
PBX / KS Apps Svr VoIP, Router Integrated Mgmt
Small Site Physical Integration
PSTN
Small Site Physical Integration
IP LAN/WAN
Ethernet
IP Phones
26
??????????? PSTN ?? ????? ??????????? ? IP
?????????? ???? ??????? ?????????, ???????
???????????, ??????? ????????? ????????????
?????????? ????? ?????????? ? ???????? ???????
Q.931
SS7
SS7
UNI
NNI
FXS
FXS
?????????? ?????????? ?????????? ??? ??????????
????? ??????????, ?????????? ????? ????
(statefull) ??????? ??????? ?????????
27
IP-???? ??????? ????????? (??????????) ? ???????
??????????? (IP-??????????????)
???????????? IP-???? (??? ????? ???????) ??
???????????? ???????? ????????????
?????? IP
?????????????? ?????????? ??? ?????? - ???
???????????? ?????? ????? ????????, ?? ?????????
?????????? ????? ????????? ??????????????
28
???????? ???????? IP-????????? ????? ???????
IP-???? ?????? ??????????? ????????? ??????????
?????????? ? PSTN
?????? IP

• ????? ???????? IP-????
• ???? ITG
• ?????????? (softswitches)
• ??????? ????????
• ??????? ??????????

29
??????? ????????? ???????????? ?????? ?
?????????? ???? ?? ????????? Q.931
?????
SS7 messages
Set up
Set up
Call proceeding
??????
Alerting
Alerting
?????
?????? ??????
Connect
?????? ??????
Connect
Connect ack
?????? ??????
????????
?????? ?? ??????
Disconnect
????????? ??????
Disconnect
Release
?????? ?? ??????
Release
Release complete
Release complete
30
?????????????? ?????? ISDN

• Direct dialing-in ????????? ???????????????
  ??????? ??????? ????????????, ????????????? ?
  ISDN-??????????? PBX, ??? ??????????????
  ?????????
• Calling line identification presentation
  ?????????????? ?????????? ??????? ??????
  ?????????? ???????
• Calling line identification restriction
  ??????????? ?????????????? ?????????? ???????
  ?????? ?????????? ???????
• Call transfer ??????? ????????? ?????? ???????
  ???????
• Call forwarding busy, no reply, unconditional
  ????????????? ?????? ?? ????????? ???????????
  ????????, ??? ?? ?????? ??? ???????????
• Line hunting ????????????? ??????? ??
  ???????????? ????? ?? ?????? ??????????? ???
  ??????????.
• Call waiting, hold ??????????? ????????????,
  ??? ???????????? ? ???-??, ? ??????? ??????
  ??????. ???????????? ????? ??????????? ???????
  ??? ????????? ?????.
• Conference call ??????????? ??????????
  ????????????? ???????????? ??????????? ?
  ?????????
• Closed user group (VPN) ????? ?????? ?????
  ????????????????? ?????? ????? ?????, ???? ???
  ????????? ?????? ????? ???????? ? ??????? ?????

IP ????????? ?????? ?????????? ??? ?? ????? ?????!
31
???? ?????????? SS7/IN
32
??????? ????????? ???????????? ?????? ?
?????????? ???? ?? ????????? ISUP/SS7
Set up
Initial Address Message (IAM)
Initial Address Message (IAM)
Initial Address Message (IAM)
Change band/rate(optional)
Optional end-to-end interchange
Address Complete (AC)
Address Complete (AC)
Address Complete (AC)
Answer
Answer
Answer
Release
Disconnect
Release
Release
Disconnect
Released
Released
Release
Released
Release compl.
Release compl.
Release compl.
Release
33
???????????????? ???? ????????? ??????????????
????? ?? ??????? ??????????
555-10-34
SSP
INAP-?????
SS7
???????????? ???????
INAP-??????
800-236-450
SCP
SSP Service Switching Point SCP Service
Control Point SMP Service Management Point SCEP
Service Creation Environment Point
236-450
555-10-34
236-451
310-23-69
SCEP
SMP
34
?????? ???????? ???????????? ??????
?????????? ????? ????????? ????????? ? SCP
S?P
??????????? ??????????
?????? ?????
??????? ???????????? ??????
????? ??????????
SSP

• ????????? ????????
• ?????? ?????
• ?????????? ???? ??????
• ?????? ??????
• ?????????????

35
????? ????? CS-1 ???????????????? ????

• Automatic Alternative Billing ????? ? ??????
  ????????, ????? ????????? ?? ???? ????????,
  ??????? ????????? ??? ???? ?????? ? ??
  ??????????? ? ?????????? ??? ?????????? ???????
• Abbreviating Dialing ??????????? ?????,
  (??????? VPN)
• Credit Card Calling ????? ?? ????????? ?????.
  ??????? ?????? ??????? ????? ????? ????? ? PIN,
  ????? ????? ??????????? ????????
• Conference call ??????????? ??????????
  ????????????? ???????????? ??????????? ?
  ?????????
• Call Distribution ????????????? ????????
  ???????
• ???????????
• ??????????
• ????????????
• Call forwarding ??????????? ?????????????
  ?????? ?? ?????? ?????
• Call Rerouting Distribution ??? ????????????
  ???????? (??????? ?????, ?? ????????, ???????????
  ??????? ? ??.) ????? ???????????? ?? ??????
  ?????, ???? ???????????? ? ?????????
  ??????????????? ???????? ?????????, ???? ????????
  ?? ????????.

36
????? ????? CS-1 ???????????????? ????
(???????????)

• Destination Call Routing ????????????? ???????
  ?? ?????? ???????????? ?????????? ?? ???????
• ????? ???, ???? ?????? ? ?.?.
• ?????????????? ????????? ??????????? ????????
• ??????????? ????????????
• ???????????? ????????????? ????????,
  ??????????????? ?????????.
• Follow Me Diversion ????????????? ????? ??
  ?????. ??????? ????? ????????? ????? ????? ???
  ????????????? ??????? ?? ??? ?????????? ?????
• Freephone ?????????? ?????. ????? ?? ?????
  ????????? ?? ???? ????????? ??????. ????????
  ???????? ?????? ?? ??????? ?????? ? ??????????
  ????? ?????????.
• Premium Rate ?????? ? ?????????????? ???????.
  ???????? ??????????? ????? ??? ?? ??????????
  ?????, ??? ? ?? ?????????????? ??????????,
  ??????????????? ?????????? ??????. ?????
  ?????????????? ????? ?????????? ???? ?
  ??????????.
• Televoting ???????????????. ????? ?????????????
  ?????? ? ??????? ????. ??? ?????? ?????????
  ??????? ???????????? ?????? ??????.

37
??????????????? ????????????? IP Telephony

• ????????? ??????????/???????????? (codec ??
  ?????? Digital Signal Processor,DSP )
• ????????? ??????????????? ???? RTP, RTCP
• ????????? ???????????? IP Telephony H.323 ? SIP
• ?????????????? ????? MGCP, MEGACO
• ??????????? Quality of Service (QoS)

38
????????? IP-?????????
Key in Voice Quality
Transmission performance considerations for
voiceband services carried on networks that use
Internet Protocol
39
?????? ? DSP
5.3/ 6.3 Kbps
Analog Voice
Digital Voice
16 /24 Kbps
40
??????????? ????????? ??????
t
IP
???????? ??????????? N x t
??? ???????? ?????? ???????? ??????????? ?.?. lt
20 - 30 ??
?????? ?????? lt 160 - 240 ???? (1 ???? 125 ???
gt 160/8) ?????? ?????? ???????????? ?? ??????
???????? ????????? ????????, ?? ? ???????? ?????
????????? ?????????? ???? ?? ????? ???? ??????
??????? ??????? ??????, ?.?. gt 80 160 ????
41
???????? ???????? DTMF ? IP-?????????

• ??????????? ??????? ???????? DTMF ???
  ????????????? G.711 ?? ?????? ??????? ?????????
• ???????????? ?????? ??? ?????????? ?????????
  ??????????? ??????? ? ????????????? ????????????
  ???? ????????? ????? DTMF ?????? ??????????
  ????? ???? IP-?????????
• ???????
• ???????????? ????? ????????? ????? ????????
  DTMF (0, 1, ,9, , ) ? ??????????? ?????????
  ???????????? ?????????
• ????????????? ????? ?????? VoIP ????????
  ??????????? ?????? ?? ????????? RTP ?????????
  ?????????? ??????? ??????? ??????? ??????,
  ???????? ??? ??????????? ??????????????
  ?????????????? ? ?????????????

42
??????? ???????? ?? ???????? ??????
?????????????? ????????? ????????
????????
100 150 200
300 ??
??? ????? ITG ?????? ???????? 60-70 ?? (??????
??????) ???????? 90 ?? ??? ???????? ????
43
???????? VoIP, ?????????? ???????? ??????
1. ?????????? ??? 2. ?????????? ???? (Voice
Activity Detection) 3. ????????? ???????????
???? ?????? ???? (Comfort Noise Generator)
???????? ??????? (dB)
????? ??????/??? (dB)
???????? ?????????
??????????? ????
????????? ????
44
ITU codec StandardsBusiness Quality Voice
Gateway
Gateway
IP Network
PSTN
PSTN
Quality of Voice over Premium Quality IP network
approaches PSTN
???? 30??, 16 MIPS
???? 10 ??, 20 MIPS
45
Quality of Service (QoS)
Network QoS IntServ/DiffServ
IP WAN
IP LAN
IP LAN
Application QoS RTP/RTCP
RTP Real Time Protocol (RFC 1889) RTCP Real Time
Control Protocol (RFC 1890) Intserv Resource
Reservation Protocol (RSVP) DiffServ Differentiate
d Services (Packet Prioritization)
46
????????? ???????? ????????? ?????????? ?
???????? ??????? RTP ? RTCP
?????????? - ????????????? ???? ?????? -
????????? ?????????????????? ?????? - ?????????
??????? - ?????????? ???????? - ???????? ??
?????????? ???????????
?? ???????????? ??? - ??????????? ?????????????
???????? ?????? - ?????????????? ????? QoS
47
?????? ?????? RTP
48
?????????? ????? RTP P - ??????? ??????????
(padding?) - ??????? ????????? ?????????
?????????? (????????? ???? ?????????? ????????
????? ???? ??????????) PT - ??? ?????? (Payload
Type), ???????? ????? G.729 SSRC - ?????????????
????????? ?????????? ?????? CSRC - ?????????????
??????????????? ????????? (????????, ??????????
???????????) Sequence Number - ????????????????
????? ??????? RTP-??????, ????????? ???????? -
????????? (??? ?????? ??? ????????) Timestamp
-????????? ??????? ??????? ????? ??????,
????????? ???????? - ?????????, ??????????
??????? ?.?. ?????????? ??? ??????? ??????????
(?????, ?????)
49
??????? ????????? RTCP

• 1. ????????? ?????????? ???????? ????? ??
  ?????????? ? ???????? ???????? -
• ????????? ????????? ?????????? ???????????
  ????????????
• ???????? ????? ??? ????????? ????????
• 2. ?????????? ???????????? ??? ???????????
  ????????? (e-mail, ????? ????????,
  ?????????????? ????????????)
• 3. ???????? ?????????? ?????????? ?????? ???
  ??????????? ??????? ???????? ????????? ?????????
  - ????????????????
• 4. ???????? ?????????? ? ?????? ???? ?????????? -
  ??????? ??? ????????? ??????????? ??????

50
???? ??????? RTCP
SR (Sender Report) - ?????????? ?? ????????
???????????? (jitter ? ?.?.) RR (Receiver
Report) - ?????????? ?? ??????????? SDES -
?????????? ??????, ?????????? ???????????? ???
???????????, ????????? ?????????? ??????????? ???
????????????? ?????? ?????? ? ?.?. BYE -
????????? ?????????? ??????? ? ?????? APP -
????????????? ??? ?????????? ???????
51
????????? ???????????? IP-?????????

• H.323 v2
• ???????? ITU-T ?????? ???????? IP-telephony
• ?????????? ?????????? ??? ????? ? ?????
  ??????????? ????? LAN
• Session Initiation Protocol, SIP ???????? IETF
• Media Gateway Control Protocol (MGCP) ????????
  IETF
• MEGACO/H.248 - ?????????? ???????? IETF/ITU-T

52
???????? ???????????H.323 v2

• Gatekeeper
• ?????????? ??????? (IP, telephone)
• ???????? ???????
• ????? ? ???????? ????????
• ?? ?????????? ??? ??????????? ??????

• Terminals
• PC, IP phones, set-top boxes

• Endpoints
• ????? ??????? ? ????????? ?????? (??????)

• Gateway
• ?????????????? ? ??????????? ?????? ????? ? PSTN

• Multipoint Control Unit (MCU)
• ????????? ????????????? ???????????

53
H.323 Architecture
??????????? H.323
54
H.323 v2 Operations
H.323 Gatekeeper
Location, Call Admission, and Registration
Location, Call Admission, and Registration
H.323 Endpoint
Call Setup, Capability Exchange, Connection
Establishment, and Call Status
H.323 Endpoint
RTP Audio
55
?????? IP-????????? ? ?????? TIPHON
56
TIPHON Acronyms

• SCN - Switched Circuit Networks
• SC - Service Control
• CC - call control
• BC - bearer control
• MC - media control
• ICF - interconnect function
• TF - transport function
• TRM - transport resource manager
• TPE - transport policy entity
• TU- transport usage

57
Meta-protocol
58
H.323 Protocol Stack

• ????? ?????? (G.711, G.723.1, G.729, G.728, ?
  ?.?.) ? ????? ?????? (H.261, H.263) ?????????????
  ? ??????????????? ?????? ??????
• ?????? ?????? ???????????????? ? ??????? RTP/RTCP
• RTP ????????? ??????
• RTCP ????????? ????????? ??????????
• RTP/RTCP ???????? ????? UPD
• ???????????? - ????? ???????? ????????? TCP
• RAS - registration, admission, status
• Q.931 - ???????????? ? ?????????? ??????????
  (call setup and termination) - ?? ?? ?????? RTP
• H.245 - ????? ????????????? ? ?????????? ????????
  RTP

59
H.323 Protocol Stack
60
????????? H.323

• ???????? ???? LAN
• ???????????? ??????????? ?????????????? ?
  ???????? ??????? ? ??????? ?????????? H.323
• ?????? ????????????
• ????????? (?????) ?????? (G.711 - ??? ???????)
• ???????????? - Q.931, H.245, RAS
• ???????????
• Video
• Data

61
????????? H.323
62
H.323 Gateway

• ????????? ????? LAN ? ????? ? ??????????? ???????
  (Switched Circuit Network)
• ??????????? ???????????????? ????????? ? ???????
  ????? ????? ?????? ?????
• ???????????? ? ?????? ??????????
• ?????????? ? ??????????? ??????
• ?????? ???? IP/PSTN

63
H.323 Gateway
64
H.323 Gatekeepers

• ???????????? ??????? (???????, Netmeeting ??
  ?????????? gatekeeper??)
• ????????? ????? (zone - ????? ????????? ???
  ??????????? ?????? ???????????)
• ?????? ? ???? ??????? ???? gatekeeper
  ????????????? gatekeeper ????? ???????????? ???
  ?????????????? ??? ??????? ????????
• ?????? ???????????? ????? ??????????? ?????????,
  ?????????? ?? ??????????, ?? ????? ????
  ???????????? ? ?????? ??? ??????????
• (??????? Cisco IOS )

65
H.323 Gatekeepers

• ???????????? ???????
• ?????????? ??????? ? ????????????? (routing -
  TRIP) john.smith_at_abc.com -gt IP, 371-712-67-85
• ???????? ??????? (????????????????)
• ??????????? ???????? ?????????? ??????????? -
  ????????? ????????
• ?????????? ?????
• ???????????? ???????
• ?????????? ???????? - ???????????????? ?????????
  ?????? Q.931 ????? ????????? ???????
• ??????????? ???????, ?????????? ???????
  ???????????, ?????????? ???????? ? ?????????
  ???????
• ???????? ?????? ? ??????? ????????
• ??????????? Gatekeeper management information
  (MIB)
• ??????? ?????????? ?????? (directory services)

66
H.323 MCU

• MCU - Multipoint Control Unit
• ???????? ?????, ?????????????? ??????????? ?????
  3-?? ? ????? ????????? ???????
• ????? ???? ????????? ??????????? ???
  ????????????? ? gateway, gatekeeper ??? terminal
• ?????? ??????? ?? multi-point controller (MC) ?
  multi-point processor (MP)
• MC - ????????? ???????????? - ?????????????? ?
  ?.?.
• MP - ???????? ?????? ?????? ?? ???????? ????? ?
  ???????????? ?? ????? ??????????? ???????????

67
???????????????? ? ?????????????????? ???????????

• ???????????????? - MCU ????????? ????????????
  (MC) ? ???????????? ?????? ?????? (MP)
• ?????????????????? - MCU ???????????? ??????
  ????????????, ? ?????? ?????? ?????????
  ??????????????? ????? ????????? ???????
• ? ????????? ?????? MCU ???????? ??? MP

• ? ????? ? ??????????? ?????? ????????????
  ??????????? ?????
• ???????? ?????????? ????????? ??????? ?? ??????
  ????????? ? ????? ?????? ?????? ???????? ?? ????
  ???????? ????? ??????? ? ??? ?????, ? ???????
  ??? ???????? ?? ?????????

68
?????? ????????????

• ??????????, ????? ???????????? ?????????
  ?????????? ????? gatekeeper, ? ????? -
  ??????????????? ????? ????? ????????? ???????
• ??? ?????? ????????? ?????????? ????? gatekeeper,
  ??? ?????? ??? ???????? ? ???????????????
  (????????????? ????????????)
• ?????? gatekeeper ?????? - ????? ??????
  ???????????? ???????
• ?????? ?????? ??????? ?? ?????????? ?????
  gatekeeper

69

Direct Endpoint Call Signalling

70

Gatekeeper Routed Call Signalling (Q.931)

71
Gatekeeper Routed Call Signalling (Q.931/H.245)
72
?????? ?????????????? ????? ????????? A ? B ??
?????? Gatekeeper Routed Call Signalling (Q.931)
?
73
?????????????? ???????? ? ? ?

• ????? ???????????? ??????????
• ??????????? ? ??????????? ?? gatekeeper? - RAS
  ?????
• ????????????? ??????? ????? ????????? ???????
  ????? gatekeeper - Q.931 call signalling
• ????????? ?????????????? ? ????? ?????????????? -
  H.245 call control
• ???????????? ?????????????? ?????? - H.245 call
  control
• ?????????? ?????????? - H.245 call control
  Q.931 call signalling

74
??????????? - Discover Gatekeeper (RAS)

• ?????? ???????? ????? Multicast Gatekeeper
  Request packet (??? ??? gatekeeper?)
• Gatekeeper ???????? ??????? Gatekeeper
  Confirmation ??? ??????? Gatekeeper Reject

75
??????????? - Discover Gatekeeper (RAS)
??????? ?
??????? B
??????????
GRQ 224.0.1.41
GRQ 224.0.1.41
GCF - ????? RAS
GCF - ????? RAS
76
??????????? ? Gatekeeper? (RAS)

• ?????? ?????? ???????? ?????? Gatekeeper
  Registration Request, ??????? gatekeeper? ????
  ????? ??? ??????????
• Gatekeeper ???????? - Registration Confirmation
  ??? Registration Rejection
• ? ??????? ??? ??????? - ? ? ? -?????????????? ?
  gatekeeper? A

77
??????????? ? gatekeeper?
??????? ?
??????? B
??????????
GRQ 224.0.1.41
GRQ 224.0.1.41
GCF - ????? RAS
GCF - ????? RAS
RRQ/URQ
RRQ/URQ
RCF/RRJ/UCF
RCF/RRJ/UCF
78
Call Admission (RAS)

• ?????? A ???????? ?????? Admission Request (????
  ? ??????? ???? ????? ?? ?????? 134-57-30 ?)
  ?????? ???????? ???????? ???????????? ??????????
  ???????????, ????????? ??? ??????
• Gatekeeper ???????? ??????? Admission
  Confirmation
• ?????????? ??????????? ??? ?????? ??????????????
  ??? ???????????
• ????? ??? ???????????? ?????? ???????????? ??????

79
?????????? ??????
??????? ?
??????? ?
??????????
GRQ 224.0.1.41
GRQ 224.0.1.41
GCF - ????? RAS
GCF - ????? RAS
RRQ/URQ
RRQ/URQ
RCF/RRJ/UCF
ARQ
ACF
80
Call Setup ????? Gatekeeper (Q.931)

• ?????? A ???????? ????????? Call setup
  gatekeeper?
• Gatekeeper ?????????????? ??? ????????? ??????? B
• ???? ?????? B ???????a?? ?????, ?? ?? ????????
  ?????? Admission request gatekeeper?
• ???? gatekeeper ???????? ????? ??????, ??
  ?????? B ???????? ????????? Connect ??????? A
  , ????????? ? ??? ????? ?????? H.245 call control
  channel ??? ?????? ?????????????

81
???????????? ??????????
??????? ?
??????? ?
??????????
ARQ
ACF
Setup
Setup
Call Proceeding
Call Proceeding
ARQ
ACF/ARJ
Alerting
Alerting
Connect
Connect
TerminalCapabilitySet
TerminalCapabilitySet
TerminalCapabilitySetAck
TerminalCapabilitySetAck
82
????? ????????????? (H.245)

• ??????? ???????????? ??????????? Terminal
  Capability Set ? ???????????, ???????????? ??
  ??????????? ?? ???????? ??????????????
  ???????????, ?? ???? ?????????? ?????/?????
  ???????
• ??? ???????????? ??????????? ?????????? MCU
• ????? ?????? ????????????? ??????? ????? ???????
  ??????????? ????? ?????? ???????? ??????
• ??????????? ?????? ?????? ??????????????
  ???????????

83
???????????? ?????????????? ???????

• ??? ???????? ??????????? ?????? ??? ?????? ??????
  ?????? ???????? ????????? Open Logical Channel
  (H.245)
• ??????????? ?????? ???????? ?????????? Open
  Logical Channel Acknowledgement (H.245)
• ?????? ?????? ?????????? ????? ?????????? ??????,
  ??????????? ????????? - ????? ???????? ??????
• ????? ???????????? ??????? ?????? ??? ??????????
  ????? ? ??????? ???????? ?????? ????????? ???
  ????????? ?????? ??? ??????

84
???????????? ??????????????? ???????
??????? ?
??????? ?
??????????
TerminalCapabilitySet
TerminalCapabilitySet
TerminalCapabilitySetAck
TerminalCapabilitySetAck
H.245
MasterSlaveDetermination
MasterSlaveDetermination
MSDAck
MSDAck
OpenLogicalChannel
??????????? ??????????-?????? ?????
OpenLogicalChannel
OpenLogicalChannelAck
OpenLogicalChannelAck
????????
85
?????????? ??????

• ????? ??????? ????? ????????? ?????
• ????? ?????? ? ????????? ?????
• ??????? A ????????? ???????? ?????? ? ?????????
  ?????????? ??????
• ?????? A ???????? ??????? End Session (H.245)
• ?????? B ????????? ?????????? ?????? ????????
  ?????? ? ???????? ??????? End Session
• ?????? A ????????? ??????????? ????? H.245
• ???? ????? ???????????? ?????? ??? ??????, ??
  ?????????? ????????? Release Complete ?????
  ????????? ??? ???????? ????? ?????? (Q.931)

86
?????????? ??????
??????? ?
??????? ?
??????????
????????
EndSessionCommand
EndSessionCommand
Release Complete
Release Complete
DisengageRequest
DisengageRequest
DisengageConfirm
DisengageConfirm
87
????? ???????? H.323 Version 2

• H.235 - ???????????? ? ??????????????, ????????,
  ?????? ??? ??????????? ? gatekeeper?
• H.450.x - ?????????????? ???????, ????????
  ??????????????? ??????
• ??????? ???????????? ??????
• ????? ????????? ?????????
• ???????????? ?????????? Q.931 Fast Start, ???????
  ???????? ??????? ????????? ????????????
  ????????? OpenLogicalChannel

88
???????? H.323

• ?????????????? Inter - Gatekeeper
• ??????? ???????? H.323 ?? ???????????????
  ????????? ??????, ??????? ?????????? ??? ???????
  ?????
• ????????? ?????? Inter-gatekeeper ???????????
  ??????????? ???? ????? ? ????????????? ??????? ?
  ??-????????? ??????? (TRIP - ?????? BGP)
• ????????????? ?????????? ????? gatekeeper???
  clearing house - ??????? ?????? ?????
  ???????????? - (OPS ?????? TIPHON)