1、 International Telecommunication Union ITU-T H.245TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (05/2011) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMSInfrastructure of audiovisual services Communication procedures Control protocol for multimedia communication Recommendation ITU-T H.245 ITU-T H-SER
2、IES RECOMMENDATIONS AUDIOVISUAL AND MULTIMEDIA SYSTEMS CHARACTERISTICS OF VISUAL TELEPHONE SYSTEMS H.100H.199 INFRASTRUCTURE OF AUDIOVISUAL SERVICES General H.200H.219 Transmission multiplexing and synchronization H.220H.229 Systems aspects H.230H.239 Communication procedures H.240H.259Coding of mov
3、ing video H.260H.279 Related systems aspects H.280H.299 Systems and terminal equipment for audiovisual services H.300H.349 Directory services architecture for audiovisual and multimedia services H.350H.359 Quality of service architecture for audiovisual and multimedia services H.360H.369 Supplementa
4、ry services for multimedia H.450H.499 MOBILITY AND COLLABORATION PROCEDURES Overview of Mobility and Collaboration, definitions, protocols and procedures H.500H.509 Mobility for H-Series multimedia systems and services H.510H.519 Mobile multimedia collaboration applications and services H.520H.529 S
5、ecurity for mobile multimedia systems and services H.530H.539 Security for mobile multimedia collaboration applications and services H.540H.549 Mobility interworking procedures H.550H.559 Mobile multimedia collaboration inter-working procedures H.560H.569 BROADBAND, TRIPLE-PLAY AND ADVANCED MULTIMED
6、IA SERVICES Broadband multimedia services over VDSL H.610H.619 Advanced multimedia services and applications H.620H.629 IPTV MULTIMEDIA SERVICES AND APPLICATIONS FOR IPTV General aspects H.700H.719 IPTV terminal devices H.720H.729 IPTV middleware H.730H.739 IPTV application event handling H.740H.749
7、 IPTV metadata H.750H.759 IPTV multimedia application frameworks H.760H.769 IPTV service discovery up to consumption H.770H.779 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T H.245 (05/2011) i Recommendation ITU-T H.245 Control protocol for multimedia communicatio
8、n Summary Recommendation ITU-T H.245 specifies syntax and semantics of terminal information messages as well as procedures to use them for in-band negotiation at the start of or during communication. The messages cover receiving and transmitting capabilities as well as mode preference from the recei
9、ving end, logical channel signalling, and Control revising clause B.3.2 to indicate that ITU-T H.323 systems should use the dynamic payload type specified in the ITU-T H.245 OpenLogicalChannelAck message instead of the dynamic payload type specified in the ITU-T H.245 open logical channel message; d
10、efining a similar mechanism for logical channels that use multiple payload types; and defining a new capability in a new annex, Annex T, that specifies that an endpoint is capable of using the dynamic payload type replacement mechanisms in the ITU-T H.245 OpenLogicalChannelAck message. History Editi
11、on Recommendation Approval Study Group 1.0 ITU-T H.245 1996-03-20 15 2.0 ITU-T H.245 1997-07-11 16 3.0 ITU-T H.245 1998-02-06 16 4.0 ITU-T H.245 1998-09-25 16 5.0 ITU-T H.245 1999-05-27 16 6.0 ITU-T H.245 2000-02-17 16 7.0 ITU-T H.245 2000-11-17 16 8.0 ITU-T H.245 2001-07-29 16 9.0 ITU-T H.245 2003-
12、02-06 16 10.0 ITU-T H.245 2003-07-14 16 11.0 ITU-T H.245 2005-01-08 16 12.0 ITU-T H.245 2005-10-07 16 13.0 ITU-T H.245 2006-05-29 16 14.0 ITU-T H.245 2008-06-13 16 15.0 ITU-T H.245 v15 2009-12-14 16 16.0 ITU-T H.245 v16 2011-05-14 16 ii Rec. ITU-T H.245 (05/2011) FOREWORD The International Telecommu
13、nication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff
14、 questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommend
15、ations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendat
16、ion, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperabilit
17、y or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that complia
18、nce with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity o
19、r applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to im
20、plement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2012 All rights reserved. No part of this publication may be reproduced, by any
21、 means whatsoever, without the prior written permission of ITU. Rec. ITU-T H.245 (05/2011) iii Table of Contents Page 1 Scope 1 2 References. 1 3 Definitions 6 4 Abbreviations 8 5 General 9 5.1 Master-slave determination 9 5.2 Capability exchange . 9 5.3 Logical channel signalling procedures . 10 5.
22、4 Receive terminal close logical channel request 11 5.5 ITU-T H.223 multiplex table entry modification . 11 5.6 Audiovisual and data mode request 11 5.7 Round-trip delay determination 11 5.8 Maintenance loops 11 5.9 Commands and indications . 11 Annex A Messages: Syntax 12 Annex B Messages: Semantic
23、 definitions . 80 B.1 Master-Slave Determination messages . 80 B.2 Terminal capability messages . 81 B.3 Logical channel signalling messages 112 B.4 Multiplex Table signalling messages . 122 B.5 Request Multiplex Table signalling messages . 123 B.6 Request Mode messages . 124 B.7 Round-trip Delay me
24、ssages 128 B.8 Maintenance Loop messages 128 B.9 Communication Mode Messages . 129 B.10 Conference Request and Response Messages 130 B.11 Multilink Messages 133 B.12 Logical Channel Bit rate Change Messages . 135 B.13 Commands 136 B.14 Indications 142 B.15 Generic messages . 149 Annex C Procedures .
25、 150 C.1 Introduction 150 C.2 Master-slave determination procedures 153 C.3 Capability exchange procedures . 163 C.4 Unidirectional Logical Channel signalling procedures 171 C.5 Bidirectional Logical Channel signalling procedures 184 iv Rec. ITU-T H.245 (05/2011) Page C.6 Close Logical Channel proce
26、dures . 199 C.7 ITU-T H.223 Multiplex Table Procedures . 205 C.8 Request Multiplex Entry procedures 216 C.9 Mode Request procedures 223 C.10 Round-trip delay procedures 232 C.11 Maintenance Loop procedures . 236 Annex D Object identifier assignments 246 Annex E ISO/IEC 14496-2 Capability Definitions
27、. 250 Annex F Logical Channel Bit-Rate Management Capability Definitions 253 Annex G ISO/IEC 14496-1 Capability Definitions 255 G.1 Capability Identifier 255 G.2 Capability parameters used for capability negotiations and logical channel signalling . 255 G.3 Capability parameters used for logical cha
28、nnel signalling only . 257 Annex H ISO/IEC 14496-3 Capability Definitions 258 Annex I GSM Adaptive Multi-Rate Capability Definitions . 262 I.1 Definition of mode signalling and bit stuffing to achieve octet alignment 264 Annex J TDMA ACELP Voice Codec Definitions 272 Annex K TDMA US1 Voice Codec Def
29、initions 274 Annex L CDMA EVRC Voice Codec Definitions . 276 Annex M ISO/IEC 13818-7 and Rec. ITU-R BS.1196-2 Definitions 278 Annex N IETF RFC 3389 RTP Payload for Comfort Noise . 279 Annex O L16 Capability Identifier . 280 Annex P Bounded audio stream capability . 281 Annex Q Generic Capability for
30、 N 64K Circuit Relay over IP . 282 Q.1 Introduction 282 Q.2 Description . 282 Annex R Adaptive Multi-Rate Capability Definitions . 286 R.1 Introduction 286 R.2 Description . 286 Annex S Internet Low Bit Rate Codec (iLBC) Capability Definitions 291 S.1 Introduction 291 S.2 Description . 291 Annex T D
31、ynamicPayloadType Replacement Capability Definitions . 293 Rec. ITU-T H.245 (05/2011) v Page Appendix I Overview of ASN.1 syntax 294 I.1 Introduction to ASN.1 294 I.2 Basic ASN.1 data types 294 I.3 Aggregate data types 296 I.4 Object identifier type 297 Appendix II Examples of ITU-T H.245 procedures
32、 . 298 II.1 Introduction 298 II.2 Master-slave Determination Signalling Entity . 298 II.3 Capability Exchange Signalling Entity 302 II.4 Logical Channel Signalling Entity . 303 II.5 Close Logical Channel Signalling Entity . 305 II.6 Multiplex Table Signalling Entity 306 II.7 Mode Request Signalling
33、Entity . 308 II.8 Round-trip Delay Signalling Entity 310 II.9 Bidirectional Logical Channel Signalling Entity . 311 Appendix III Summary of procedure timers and counters 314 III.1 Timers . 314 III.2 Counters 315 Appendix IV ITU-T H.245 extension procedure 316 Appendix V The replacementFor procedure
34、. 318 Appendix VI Examples of ITU-T H.263 Capability Structure Settings . 320 VI.1 Examples of Enhancement Layer ITU-T H.245 parameter setting 320 VI.2 Examples of Video Back Channel ITU-T H.245 parameter setting . 321 Appendix VII Procedure and template for defining new capabilities with ITU-T H.24
35、5 generic capabilities . 326 VII.1 Procedure 326 VII.2 Template . 327 VII.3 Example Template ITU-T H.261 328 Appendix VIII List of generic capabilities and generic messages defined in Recommendations/Standards other than this Recommendation 330 Appendix IX ASN.1 usage in this Recommendation . 334 IX
36、.1 Tagging . 334 IX.2 Types 334 IX.3 Constraints and Ranges 334 IX.4 Extensibility 334 vi Rec. ITU-T H.245 (05/2011) Page Appendix X Resolution of unidirectional and bidirectional conflict scenarios 335 X.1 Both terminals use bidirectional OLC 335 X.2 Master proposes bidirectional OLC and slave prop
37、oses unidirectional OLC 335 X.3 Master proposes unidirectional OLC and slave proposes bidirectional OLC 336 X.4 Master proposes bidirectional OLC with nullData and slave proposes unidirectional OLC . 337 X.5 Both terminals propose bidirectional OLC with nullData 337 Bibliography. 338 Rec. ITU-T H.24
38、5 (05/2011) 1 Recommendation ITU-T H.245 Control protocol for multimedia communication 1 Scope This Recommendation specifies syntax and semantics of terminal information messages as well as procedures to use them for in-band negotiation at the start of or during communication. The messages cover rec
39、eiving and transmitting capabilities as well as mode preference from the receiving end, logical channel signalling, and Control users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed
40、below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. 1 Recommendation ITU-T E.164 (2005), The international public telecommunication numbe
41、ring plan. 2 Recommendation ITU-T G.711 (1988), Pulse code modulation (PCM) of voice frequencies. 3 Recommendation ITU-T G.722 (1988), 7 kHz audio-coding within 64 kbit/s. 4 Recommendation ITU-T G.723.1 (2006), Dual rate speech coder for multimedia communication transmitting at 5.3 and 6.3 kbit/s. 5
42、 Recommendation ITU-T G.728 (1992), Coding of speech at 16 kbit/s using low-delay code excited linear prediction. 6 Recommendation ITU-T G.729 (1996), Coding of speech at 8 kbit/s using conjugate-structure algebraic-code-excited linear-prediction (CS-ACELP). 7 Recommendation ITU-T H.221 (2004), Fram
43、e structure for a 64 to 1920 kbit/s channel in audiovisual teleservices. 8 Recommendation ITU-T H.222.0 (2000) | ISO/IEC 13818-1:2000, Information technology Generic coding of moving pictures and associated audio information: Systems. 2 Rec. ITU-T H.245 (05/2011) 9 Recommendation ITU-T H.222.1 (1996
44、), Multimedia multiplex and synchronization for audiovisual communication in ATM environments. 10 Recommendation ITU-T H.223 (2001), Multiplexing protocol for low bit rate multimedia communication. 11 Recommendation ITU-T H.224 (2005), A real time control protocol for simplex applications using the
45、H.221 LSD/HSD/MLP channels. 12 Recommendation ITU-T H.225.0 (2006), Call signalling protocols and media stream packetization for packet-based multimedia communications systems. 13 Recommendation ITU-T H.230 (2004), Frame-synchronous control and indication signals for audiovisual systems. 14 Recommen
46、dation ITU-T H.233 (2002), Confidentiality system for audiovisual services. 15 Recommendation ITU-T H.234 (2002), Encryption and key management and authentication system for audiovisual services. 16 Recommendation ITU-T H.235.0 (2005), H.323 security: Framework for security in H-series (H.323 and ot
47、her H.245-based) multimedia systems. 17 Recommendation ITU-T H.243 (2005), Procedures for establishing communication between three or more audiovisual terminals using digital channels up to 1920 kbit/s. 18 Recommendation ITU-T H.261 (1993), Video codec for audiovisual services at p 64 kbit/s. 19 Rec
48、ommendation ITU-T H.262 (2000) | ISO/IEC 13818-2:2000, Information technology Generic coding of moving pictures and associated audio: Video. 20 Recommendation ITU-T H.263 (2005), Video coding for low bit rate communication. 21 Recommendation ITU-T H.310 (1998), Broadband audiovisual communication sy
49、stems and terminals. 22 Recommendation ITU-T H.320 (2004), Narrow-band visual telephone systems and terminal equipment. 23 Recommendation ITU-T H.323 (2003), Packet-based multimedia communications systems. 24 Recommendation ITU-T H.324 (2005), Terminal for low bit-rate multimedia communication. 25 Recommendation ITU-T I.363.x series, B-ISDN ATM adaptation layer (AAL) specific
