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`INTERNATIONAL TELECOMMUNICATION UNION
`
`
`
`
`
`ITU-T
`
`TELECOMMUNICATION
`STANDARDIZATION SECTOR
`OF ITU
`
`H.323
`
`(07/2003)
`
`SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS
`Infrastructure of audiovisual services – Systems and
`terminal equipment for audiovisual services
`
`Packet-based multimedia communications
`systems
`
`ITU-T Recommendation H.323
`
`
`
`AT&T, Exh. 1011, p. 1
`
`

`

`
`
`ITU-T H-SERIES RECOMMENDATIONS
`AUDIOVISUAL AND MULTIMEDIA SYSTEMS
`
`
`CHARACTERISTICS OF VISUAL TELEPHONE SYSTEMS
`INFRASTRUCTURE OF AUDIOVISUAL SERVICES
`General
`Transmission multiplexing and synchronization
`Systems aspects
`Communication procedures
`Coding of moving video
`Related systems aspects
`SYSTEMS AND TERMINAL EQUIPMENT FOR AUDIOVISUAL SERVICES
`SUPPLEMENTARY SERVICES FOR MULTIMEDIA
`MOBILITY AND COLLABORATION PROCEDURES
`Overview of Mobility and Collaboration, definitions, protocols and procedures
`Mobility for H-Series multimedia systems and services
`Mobile multimedia collaboration applications and services
`Security for mobile multimedia systems and services
`Security for mobile multimedia collaboration applications and services
`Mobility interworking procedures
`Mobile multimedia collaboration inter-working procedures
`BROADBAND AND TRIPLE-PLAY MULTIMEDIA SERVICES
`Broadband multimedia services over VDSL
`
`For further details, please refer to the list of ITU-T Recommendations.
`
`
`H.100–H.199
`
`H.200–H.219
`H.220–H.229
`H.230–H.239
`H.240–H.259
`H.260–H.279
`H.280–H.299
`H.300–H.399
`H.450–H.499
`
`H.500–H.509
`H.510–H.519
`H.520–H.529
`H.530–H.539
`H.540–H.549
`H.550–H.559
`H.560–H.569
`
`H.610–H.619
`
`
`AT&T, Exh. 1011, p. 2
`
`

`

`ITU-T Recommendation H.323
`
`
`
`Packet-based multimedia communications systems
`
`
`
`Summary
`This Recommendation describes terminals and other entities that provide multimedia communications services over
`Packet Based Networks (PBN) which may not provide a guaranteed Quality of Service. H.323 entities may provide real-
`time audio, video and/or data communications. Support for audio is mandatory, while data and video are optional, but if
`supported, the ability to use a specified common mode of operation is required, so that all terminals supporting that
`media type can interwork.
`The packet based network over which H.323 entities communicate may be a point-to-point connection, a single network
`segment, or an internetwork having multiple segments with complex topologies.
`H.323 entities may be used in point-to-point, multipoint, or broadcast (as described in ITU-T Rec. H.332) configurations.
`They may interwork with H.310 terminals on B-ISDN, H.320 terminals on N-ISDN, H.321 terminals on B-ISDN, H.322
`terminals on Guaranteed Quality of Service LANs, H.324 terminals on GSTN and wireless networks, V.70 terminals on
`GSTN, and voice terminals on GSTN or ISDN through the use of Gateways.
`H.323 entities may be integrated into personal computers or implemented in stand-alone devices such as
`videotelephones.
`Note that the title of H.323 (1996) was "Visual telephone systems and equipment for local area networks which provide a
`non-guaranteed quality of service". The title changed in Version 2 to be consistent with its expanded scope.
`Products claiming compliance with Version 1 of H.323 shall comply with all of the mandatory requirements of H.323
`(1996) which references ITU-T Recs H.225.0 (1996) and H.245 (1997). Version 1 products shall be identified by
`H.225.0 messages containing a protocolIdentifier = {itu-t (0) recommendation (0) h (8) 2250 version (0) 1} and H.245
`messages containing a protocolIdentifier = {itu-t (0) recommendation (0) h (8) 245 version (0) 2}.
`Products claiming compliance with Version 2 of H.323 shall comply with all of the mandatory requirements of this
`Recommendation, H.323 (1998), which references ITU-T Recs H.225.0 (1998) and H.245 (1998 or later). Version 2
`products shall be identified by H.225.0 messages containing a protocolIdentifier = {itu-t (0) recommendation (0) h (8)
`2250 version (0) 2} and H.245 messages containing a protocolIdentifier = {itu-t (0) recommendation (0) h (8) 245
`version (0) x}, where "x" is 3 or higher.
`Products claiming compliance with Version 3 of H.323 shall comply with all of the mandatory requirements of this
`Recommendation, H.323 (1999), which references ITU-T Recs H.225.0 (1999) and H.245 (1999 or later). Version 3
`products shall be identified by H.225.0 messages containing a protocolIdentifier = {itu-t (0) recommendation (0) h (8)
`2250 version (0) 3} and H.245 messages containing a protocolIdentifier = {itu-t (0) recommendation (0) h (8) 245
`version (0) x}, where "x" is 5 or higher.
`Products claiming compliance with Version 4 of H.323 shall comply with all of the mandatory requirements of this
`Recommendation, H.323 (2000), which references ITU-T Recs H.225.0 (2000) and H.245 (2000 or later). Version 4
`products shall be identified by H.225.0 messages containing a protocolIdentifier = {itu-t (0) recommendation (0) h (8)
`2250 version (0) 4} and H.245 messages containing a protocolIdentifier = {itu-t (0) recommendation (0) h (8) 245
`version (0) x}, where "x" is 7 or higher.
`Products claiming compliance with Version 5 of H.323 shall comply with all of the mandatory requirements of this
`Recommendation, H.323 (2003), which references ITU-T Recs H.225.0 (2003) and H.245 (02/2003 or later). Version 5
`products shall be identified by H.225.0 messages containing a protocolIdentifier = {itu-t (0) recommendation (0) h (8)
`2250 version (0) 5} and H.245 messages containing a protocolIdentifier = {itu-t (0) recommendation (0) h (8) 245
`version (0) x}, where "x" is 9 or higher.
`This version of ITU-T Rec. H.323 integrates without further modifications Annexes M3 (07/2001), P (01/2003),
`Q (07/2001) and R (07/2001), as well as Annex O, approved independently 07/2003.
`
`Source
`ITU-T Recommendation H.323 was approved by ITU-T Study Group 16 (2001-2004) under the ITU-T Recommendation
`A.8 procedure on 14 July 2003.
`
`
`
`
`
`ITU-T Rec. H.323 (07/2003)
`
`i
`
`AT&T, Exh. 1011, p. 3
`
`

`

`
`
`FOREWORD
`The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of
`telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of
`ITU. ITU-T
`is responsible for studying
`technical, operating and
`tariff 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 Recommendations 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-T's purview, the necessary standards are
`prepared on a collaborative basis with ISO and IEC.
`
`
`
`NOTE
`
`In this Recommendation, 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., interoperability 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 compliance 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 or 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 implement this Recommendation. However, implementors
`are cautioned that this may not represent the latest information and are therefore strongly urged to consult the
`TSB patent database.
`
`
`
` ITU 2004
`All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the
`prior written permission of ITU.
`
`ii
`
`ITU-T Rec. H.323 (07/2003)
`
`AT&T, Exh. 1011, p. 4
`
`

`

`
`1
`2
`3
`4
`5
`6
`
`7
`
`8
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`9
`
`
`
`CONTENTS
`
`Scope ............................................................................................................................
`Normative references....................................................................................................
`Definitions ....................................................................................................................
`Symbols and abbreviations...........................................................................................
`Conventions..................................................................................................................
`System description........................................................................................................
`6.1
`Information streams........................................................................................
`6.2
`Terminal characteristics..................................................................................
`6.3
`Gateway characteristics..................................................................................
`6.4
`Gatekeeper characteristics..............................................................................
`6.5
`Multipoint controller characteristics...............................................................
`6.6
`Multipoint processor characteristics...............................................................
`6.7
`Multipoint control unit characteristics............................................................
`6.8
`Multipoint capability ......................................................................................
`6.9
`Models for supplementary services................................................................
`Call signalling...............................................................................................................
`7.1
`Addresses........................................................................................................
`7.2
`Registration, Admission and Status (RAS) channel.......................................
`7.3
`Call signalling channel ...................................................................................
`7.4
`Call reference value........................................................................................
`7.5
`Call ID ............................................................................................................
`7.6
`Conference ID and conference goal ...............................................................
`7.7
`Endpoint call capacity ....................................................................................
`7.8
`Caller identification services ..........................................................................
`7.9
`Generic extensible framework........................................................................
`Call signalling procedures ............................................................................................
`8.1
`Phase A – Call setup.......................................................................................
`8.2
`Phase B – Initial communication and capability exchange............................
`8.3
`Phase C – Establishment of audiovisual communication...............................
`8.4
`Phase D – Call services ..................................................................................
`8.5
`Phase E – Call termination .............................................................................
`8.6
`Protocol failure handling ................................................................................
`Interoperation with other terminal types ......................................................................
`9.1
`Speech-only terminals ....................................................................................
`9.2
`Visual telephone terminals over the ISDN (ITU-T Rec. H.320)....................
`9.3
`Visual telephone terminals over GSTN (ITU-T Rec. H.324) ........................
`Visual telephone terminals over mobile radio (ITU-T Rec. H.324/M −
`9.4
`Annex C/H.324) .............................................................................................
`
`Page
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`ITU-T Rec. H.323 (07/2003)
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`iii
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`AT&T, Exh. 1011, p. 5
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`10
`
`9.5
`9.6
`
`Visual telephone terminals over ATM (H.321 and H.310 RAST).................
`Visual telephone terminals over guaranteed quality of service LANs
`(ITU-T Rec. H.322)........................................................................................
`Simultaneous voice and data terminals over GSTN (ITU-T Rec. V.70)........
`9.7
`T.120 terminals on the packet based network ................................................
`9.8
`Gateway for H.323 media transport over ATM .............................................
`9.9
`Optional enhancements.................................................................................................
`10.1
`Encryption ......................................................................................................
`10.2 Multipoint operation.......................................................................................
`10.3
`Call Linkage in H.323 ....................................................................................
`10.4
`Tunnelling of non-H.323 signalling messages ...............................................
`10.5
`Use of RTP payload for DTMF digits, telephony tones and telephony
`signals.............................................................................................................
`11 Maintenance..................................................................................................................
`11.1
`Loopbacks for maintenance purposes ............................................................
`11.2 Monitoring methods .......................................................................................
`Annex A – H.245 messages used by H.323 endpoints ............................................................
`Annex B – Procedures for layered video codecs .....................................................................
`B.1
`Scope ..............................................................................................................
`B.2
`Introduction ....................................................................................................
`B.3
`Scalability methods ........................................................................................
`B.4
`Call establishment ..........................................................................................
`B.5
`Use of RTP sessions and codec layers ...........................................................
`B.6
`Possible layering models ................................................................................
`B.7
`Impact on multipoint conferences ..................................................................
`B.8
`Use of network QOS for layered video streams.............................................
`Annex C – H.323 on ATM ......................................................................................................
`C.1
`Introduction ....................................................................................................
`C.2
`Scope ..............................................................................................................
`C.3
`Architecture ....................................................................................................
`C.4
`Protocol section ..............................................................................................
`Annex D – Real-time facsimile over H.323 systems...............................................................
`D.1
`Introduction ....................................................................................................
`D.2
`Scope ..............................................................................................................
`D.3
`Procedures for opening channels to send T.38 packets..................................
`D.4
`Non-Fast Connect procedures ........................................................................
`D.5
`Replacing an existing audio stream with a T.38 fax stream...........................
`D.6
`Usage of the MaxBitRate in messages ...........................................................
`D.7
`Interactions with gateways and T.38/Annex B devices..................................
`
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`165
`165
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`iv
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`ITU-T Rec. H.323 (07/2003)
`
`AT&T, Exh. 1011, p. 6
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`

`

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`
`
`Annex E – Framework and wire-protocol for multiplexed call signalling transport...............
`E.1
`Scope ..............................................................................................................
`E.2
`H.225.0 call signalling over Annex E ............................................................
`Annex F – Simple endpoint types............................................................................................
`F.1
`Introduction ....................................................................................................
`F.2
`Specification conventions...............................................................................
`F.3
`Scope ..............................................................................................................
`F.4
`Normative references......................................................................................
`F.5
`Abbreviations .................................................................................................
`F.6
`Simple (Audio) Endpoint Type – System functionality overview .................
`F.7
`Procedures for Simple Endpoint Types..........................................................
`F.8
`Security extensions.........................................................................................
`F.9
`Interoperability considerations .......................................................................
`F.10
`Implementation notes (Informative)...............................................................
`Annex G – Text conversation and Text SET ...........................................................................
`G.1
`Introduction ....................................................................................................
`G.2
`Scope ..............................................................................................................
`G.3
`References ......................................................................................................
`G.4
`Definitions ......................................................................................................
`G.5
`Procedures for opening channels for T.140 text conversation .......................
`G.6
`Framing and buffering of T.140 data .............................................................
`G.7
`Interaction with text conversation facilities in other devices .........................
`G.8
`Multipoint considerations...............................................................................
`G.9
`Text SET: Text Conversation Simple Endpoint Type....................................
`Annex J – Security for H.323 Annex F....................................................................................
`J.1
`Introduction ....................................................................................................
`J.2
`Specification conventions...............................................................................
`J.3
`Scope ..............................................................................................................
`J.4
`Abbreviations .................................................................................................
`J.5
`Normative references......................................................................................
`J.6
`Secure Audio Simple Endpoint Type (SASET) .............................................
`Annex K – HTTP-based service control transport channel .....................................................
`K.1
`Introduction ....................................................................................................
`K.2
`Service control in H.323.................................................................................
`K.3
`Usage of HTTP...............................................................................................
`K.4
`Example scenarios..........................................................................................
`K.5
`References ......................................................................................................
`
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`ITU-T Rec. H.323 (07/2003)
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`v
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`AT&T, Exh. 1011, p. 7
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`

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`
`
`
`Annex L – Stimulus control protocol.......................................................................................
`L.1
`Scope ..............................................................................................................
`L.2
`Introduction ....................................................................................................
`L.3
`Stimulus framework .......................................................................................
`L.4
`References ......................................................................................................
`Annex M1 – Tunnelling of signalling protocols (QSIG) in H.323..........................................
`M1.1
`Scope ..............................................................................................................
`M1.2 Normative references......................................................................................
`M1.3 Endpoint procedures.......................................................................................
`M1.4 Tunnelling of QSIG connection oriented call independent signalling ...........
`M1.5 Gatekeeper procedures ...................................................................................
`Annex M2 – Tunnelling of signalling protocols (ISUP) in H.323...........................................
`M2.1
`Scope ..............................................................................................................
`M2.2 Normative references......................................................................................
`M2.3 Endpoint procedures.......................................................................................
`M2.4 Gatekeeper procedures ...................................................................................
`Annex M3 – Tunnelling of DSS1 through H.323....................................................................
`M3.1
`Scope ..............................................................................................................
`M3.2 Normative references......................................................................................
`M3.3 Endpoint procedures.......................................................................................
`M3.4 Tunnelling of bearer-independent DSS1 signalling .......................................
`M3.5 Gatekeeper procedures ...................................................................................
`Annex O – Usage of URLs and DNS ......................................................................................
`O.1
`Scope ..............................................................................................................
`O.2
`Normative references......................................................................................
`O.3
`Informative references....................................................................................
`O.4
`H.323 URL .....................................................................................................
`O.5
`Encoding of H.323 URL in H.323 messages .................................................
`O.6
`Non-H.323 URLs and URIs within the context of H.323 ..............................
`O.7
`H.323 URL parameters...................................................................................
`O.8
`Usage of the H.323 URL................................................................................
`O.9
`Resolving an H.323 URL to IP Address using DNS......................................
`O.10 Using DNS SRV Resource Records...............................................................
`Annex P – Transfer of modem signals over H.323..................................................................
`P.1
`Scope ..............................................................................................................
`P.2
`References ......................................................................................................
`P.3
`Definitions ......................................................................................................
`P.4
`Abbreviations .................................................................................................
`P.5
`Introduction ....................................................................................................
`
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`AT&T, Exh. 1011, p. 8
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`

`
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`
`
`Capability advertisement................................................................................
`P.6
`Call establishment ..........................................................................................
`P.7
`Logical channel signalling..............................................................................
`P.8
`Annex Q – Far-end camera control and H.281/H.224 .............................................................
`Q.1
`Scope ..............................................................................................................
`Q.2
`References ......................................................................................................
`Q.3
`Introduction ....................................................................................................
`Q.4
`Far-end camera control protocol ....................................................................
`Q.5
`RTP header information .................................................................................
`Annex R – Robustness methods for H.323 entities .................................................................
`R.1
`Introduction and scope ...................................................................................
`R.2
`Normative references......................................................................................
`R.3
`Definitions ......................................................................................................
`R.4
`Abbreviations .................................................................................................
`R.5
`Overview of the two methods.........................................................................
`R.6
`Common mechanisms ....................................................................................
`R.7
`Method A: State recovery from neighbours ...................................................
`R.8
`Method B: State recovery from a shared repository.......................................
`R.9
`Interworking between robustness methods ....................................................
`R.10
`Procedures for recovery..................................................................................
`R.11 GenericData usage..........................................................................................
`R.12
`Informative Note 1: Background on robustness methods ..............................
`R.13
`Informative Note 2: Call state sharing between an entity and its backup
`peer .................................................................................................................
`Appendix I – Sample MC to terminal communication mode command .................................
`I.1
`Sample conference Scenario A.......................................................................
`I.2
`CommunicationModeTable sent to all endpoints...........................................
`I.3
`Sample conference Scenario B.......................................................................
`I.4
`CommunicationModeTable sent to all endpoints...........................................
`Appendix II – Transport level resource reservation procedures..............................................
`II.1
`Introduction ....................................................................................................
`II.2
`QOS support for H.323...................................................................................
`II.3
`RSVP background ..........................................................................................
`II.4
`The H.245 capability exchange phase............................................................
`II.5
`Open logical channel and setting up reservations ..........................................
`II.6
`Close logical channel and tearing down reservations.....................................
`II.7
`Resource reservation for multicast H.323 logical channels ...........................
`II.8
`Synchronized RSVP .......................................................................................
`
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`
`
`
`Appendix III – Gatekeeper-based user location.......................................................................
`III.1
`Introduction ....................................................................................................
`III.2
`Signalling........................................................................................................
`Appendix IV – Signalling prioritized alternative logical channels in H.245...........................
`IV.1
`Introduction ....................................................................................................
`IV.2
`Signalling........................................................................................................
`Appendix V – Use of E.164 and ISO/IEC 11571 numbering plans ........................................
`V.1
`E.164 numbering plan ....................................................................................
`V.2
`Private network number .................................................................................
`V.3
`H.323 versions 1, 2 and 3 usage.....................................................................
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`viii
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`AT&T, Exh. 1011, p. 10
`
`

`

`ITU-T Recommendation H.323
`
`
`
`Packet-based multimedia communications systems
`
`Scope
`1
`This Recommendation covers the technical requirements for multimedia communications systems
`in those situations where the underlying transport is a Packet Based Network (PBN) which may not
`provide a guaranteed Quality of Service (QOS). These packet based networks may include Local
`Area Networks, Enterprise Area Networks, Metropolitan Area Networks, In