INTERNATIONAL TELECOMMUNICATION UNION
`
`
`
`ITU-T
`
`TELECOMMUNICATION
`STANDARDIZATION SECTOR
`OF ITU
`
`H.323
`
`(02/98)
`
`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
`(Previously CCITT Recommendation)
`
`
`Petitioner Apple Inc. - Ex. 1040, p. 1
`
`

`
`
`
`
`
`ITU-T H-SERIES RECOMMENDATIONS
`AUDIOVISUAL AND MULTIMEDIA SYSTEMS
`
`Characteristics of transmission channels used for other than telephone purposes
`Use of telephone-type circuits for voice-frequency telegraphy
`Telephone circuits or cables used for various types of telegraph transmission or
`simultaneous transmission
`Telephone-type circuits used for facsimile telegraphy
`Characteristics of data signals
`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
`
`
`
`For further details, please refer to ITU-T List of Recommendations.
`
`
`H.10–H.19
`H.20–H.29
`H.30–H.39
`
`H.40–H.49
`H.50–H.99
`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
`
`
`Petitioner Apple Inc. - Ex. 1040, p. 2
`
`

`
`ITU-T RECOMMENDATION H.323
`
`
`PACKET-BASED MULTIMEDIA COMMUNICATIONS SYSTEMS
`
`
`
`Summary
`that provide multimedia
`terminals and other entities
`This Recommendation describes
`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
`Recommendation 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.
`Products claiming compliance with Version 1 of H.323 shall comply with all of the mandatory
`requirements of H.323 (1996) which references Recommendations H.225.0 (1996) and H.245
`(1996). Version 1 products can 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 Recommendations H.225.0 (1998) and H.245
`(1998). Version 2 products can 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) 3}.
`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 has been changed in this
`version to be consistent with its expanded scope.
`
`
`
`Source
`ITU-T Recommendation H.323 was revised by ITU-T Study Group 16 (1997-2000) and was
`approved under the WTSC Resolution No. 1 procedure on the 6th of February 1998.
`
`
`
`Petitioner Apple Inc. - Ex. 1040, p. 3
`
`

`
`
`
`FOREWORD
`ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of
`telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of
`the ITU. The 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 Conference (WTSC), which meets every four years,
`establishes the topics for study by the ITU-T Study Groups which, in their turn, produce Recommendations
`on these topics.
`The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in
`WTSC Resolution No. 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.
`
`
`
`
`INTELLECTUAL PROPERTY RIGHTS
`The ITU draws attention to the possibility that the practice or implementation of this Recommendation may
`involve the use of a claimed Intellectual Property Right. The 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, the 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 1998
`All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means,
`electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU.
`
`ii
`
`Recommendation H.323 (02/98)
`
`Petitioner Apple Inc. - Ex. 1040, p. 4
`
`

`
`
`
`CONTENTS
`
`
`
`1
`
`2
`
`3
`
`4
`
`5
`
`6
`6.1
`6.2
`
`6.3
`6.4
`6.5
`6.6
`6.7
`6.8
`
`Scope ..........................................................................................................................
`
`Normative references..................................................................................................
`
`Definitions ..................................................................................................................
`
`Symbols and abbreviations.........................................................................................
`
`Conventions................................................................................................................
`
`System description......................................................................................................
`Information streams....................................................................................................
`Terminal characteristics .............................................................................................
`6.2.1 Terminal elements outside the scope of this Recommendation ....................
`6.2.2 Terminal elements within the scope of this Recommendation .....................
`6.2.3 Packet based network interface.....................................................................
`6.2.4 Video codec...................................................................................................
`6.2.5 Audio codec...................................................................................................
`6.2.6 Receive path delay ........................................................................................
`6.2.7 Data channel..................................................................................................
`6.2.8 H.245 control function ..................................................................................
`6.2.9 RAS signalling function................................................................................
`6.2.10 Call signalling function .................................................................................
`6.2.11 H.225.0 layer.................................................................................................
`Gateway characteristics..............................................................................................
`Gatekeeper characteristics..........................................................................................
`Multipoint controller characteristics ..........................................................................
`Multipoint processor characteristics...........................................................................
`Multipoint control unit characteristics .......................................................................
`Multipoint capability ..................................................................................................
`6.8.1 Centralized multipoint capability..................................................................
`6.8.2 Decentralized multipoint capability ..............................................................
`6.8.3 Hybrid multipoint – Centralized audio .........................................................
`6.8.4 Hybrid multipoint – Centralized video .........................................................
`6.8.5 Establishment of common mode ...................................................................
`6.8.6 Multipoint rate matching...............................................................................
`6.8.7 Multipoint lip synchronization......................................................................
`6.8.8 Multipoint encryption....................................................................................
`6.8.9 Cascading multipoint control units ...............................................................
`
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`23
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`Recommendation H.323 (02/98)
`
`iii
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`Petitioner Apple Inc. - Ex. 1040, p. 5
`
`

`
`
`
`7
`7.1
`
`7.2
`
`7.3
`
`7.4
`7.5
`7.6
`
`8
`8.1
`
`8.2
`
`
`
`Call signalling.............................................................................................................
`Addresses....................................................................................................................
`7.1.1 Network address............................................................................................
`7.1.2 TSAP identifier .............................................................................................
`7.1.3 Alias address .................................................................................................
`Registration, Admission and Status (RAS) channel...................................................
`7.2.1 Gatekeeper discovery ....................................................................................
`7.2.2 Endpoint registration.....................................................................................
`7.2.3 Endpoint location ..........................................................................................
`7.2.4 Admissions, bandwidth change, status and disengage..................................
`7.2.5 Access tokens ................................................................................................
`Call signalling channel ...............................................................................................
`7.3.1 Call signalling channel routing .....................................................................
`7.3.2 Control channel routing.................................................................................
`Call reference value....................................................................................................
`Call ID ........................................................................................................................
`Conference ID and Conference Goal .........................................................................
`
`Call signalling procedures..........................................................................................
`Phase A – Call setup...................................................................................................
`8.1.1 Basic call setup – Neither endpoint registered..............................................
`8.1.2 Both endpoints registered to the same Gatekeeper .......................................
`8.1.3 Only calling endpoint has Gatekeeper ..........................................................
`8.1.4 Only called endpoint has Gatekeeper............................................................
`8.1.5 Both endpoints registered to different Gatekeepers......................................
`8.1.6 Optional Called Endpoint Signalling ............................................................
`8.1.7 Fast Connect Procedure.................................................................................
`8.1.8 Call setup via gateways.................................................................................
`8.1.9 Call setup with an MCU................................................................................
`8.1.10 Call forwarding .............................................................................................
`8.1.11 Broadcast call setup.......................................................................................
`8.1.12 Overlapped Sending ......................................................................................
`8.1.13 Call setup to conference alias........................................................................
`Phase B – Initial communication and capability exchange........................................
`8.2.1 Encapsulation of H.245 messages within Q.931 messages...........................
`8.2.2 Tunneling through intermediate signalling entities.......................................
`8.2.3 Switching to a separate H.245 connection ....................................................
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`Petitioner Apple Inc. - Ex. 1040, p. 6
`
`

`
`
`
`
`8.3
`
`8.4
`
`8.5
`
`8.6
`9
`9.1
`9.2
`9.3
`9.4
`9.5
`9.6
`9.7
`9.8
`
`Phase C – Establishment of audiovisual communication...........................................
`8.3.1 Mode changes................................................................................................
`8.3.2 Exchange of video by mutual agreement ......................................................
`8.3.3 Media stream address distribution ................................................................
`8.3.4 Correlation of media streams in multipoint conferences ..............................
`8.3.5 Communication Mode Command Procedures ..............................................
`Phase D – Call services ..............................................................................................
`8.4.1 Bandwidth changes .......................................................................................
`8.4.2 Status .............................................................................................................
`8.4.3 Ad hoc conference expansion .......................................................................
`8.4.4 Supplementary services.................................................................................
`8.4.5 Multipoint cascading.....................................................................................
`8.4.6 Third party initiated pause and re-routing.....................................................
`Phase E – Call termination .........................................................................................
`8.5.1 Call clearing without a Gatekeeper ...............................................................
`8.5.2 Call clearing with a Gatekeeper ....................................................................
`8.5.3 Call clearing by Gatekeeper ..........................................................................
`Protocol failure handling ............................................................................................
`Interoperation with other terminal types ....................................................................
`Speech-only terminals ................................................................................................
`Visual telephone terminals over the ISDN (H.320) ...................................................
`Visual telephone terminals over GSTN (H.324) ........................................................
`Visual telephone terminals over mobile radio (H.324/M) .........................................
`Visual telephone terminals over ATM (H.321 and H.310 RAST).............................
`Visual telephone terminals over guaranteed quality of service LANs (H.322) .........
`Simultaneous voice and data terminals over GSTN (V.70) .......................................
`T.120 terminals on the packet based network ............................................................
`
`Optional enhancements ..............................................................................................
`10
`Encryption ..................................................................................................................
`10.1
`10.2 Multipoint operation...................................................................................................
`10.2.1 H.243 Control and Indication........................................................................
`
`Maintenance ...............................................................................................................
`11
`Loopbacks for maintenance purposes ........................................................................
`11.1
`11.2 Monitoring methods ...................................................................................................
`
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`
`v
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`Petitioner Apple Inc. - Ex. 1040, p. 7
`
`

`
`
`
`
`
`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.5.1 Associate base to audio for lip synchronization............................................
`B.5.2 Enhancement layer dependency....................................................................
`Possible layering models ............................................................................................
`B.6.1 Multiple logical channels and RTP sessions for a layered stream................
`B.6.2
`Impact of one layer per logical channel and per RTP session ......................
`Impact on multipoint conferences ..............................................................................
`B.7.1 MC Impartial model......................................................................................
`B.7.2 MC Decision model ......................................................................................
`B.7.3 Multipoint conference containing endpoints on different bandwidths .........
`Use of network QOS for layered video streams.........................................................
`
`B.6
`
`B.7
`
`B.8
`
`C.3
`
`Annex C – H.323 on ATM ......................................................................................................
`C.1
`Introduction ................................................................................................................
`C.2
`Scope ..........................................................................................................................
`C.2.1 Point-to-point conferencing ..........................................................................
`C.2.2 MCU-based multipoint..................................................................................
`C.2.3 H.323 interoperability with endpoints using IP ............................................
`Architecture ................................................................................................................
`C.3.1 Overview of system.......................................................................................
`C.3.2
`Interoperation with other ITU-T H-Series endpoints....................................
`C.3.3 H.225.0 on IP over ATM ..............................................................................
`C.3.4 H.245 on TCP/IP over ATM.........................................................................
`C.3.5 Addressing for A/V streams..........................................................................
`C.3.6 Transport Capabilities added to Terminal Capability Set.............................
`C.3.7 Elements of ATM signalling.........................................................................
`C.3.8 A/V streams on RTP on AAL5 .....................................................................
`C.3.9 QOS considerations (Optional) .....................................................................
`Protocol section ..........................................................................................................
`C.4.1 ATM signalling information elements ..........................................................
`C.4.2 H.245 Usage..................................................................................................
`
`C.4
`
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`Petitioner Apple Inc. - Ex. 1040, p. 8
`
`

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`
`
`C.4.3 RTP usage .....................................................................................................
`C.4.4
`Interoperation with H.323 on IP....................................................................
`
`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 .......................................
`
`Appendix III – Gatekeeper based user location.......................................................................
`III.1
`Introduction ................................................................................................................
`III.2
`Signalling....................................................................................................................
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`Recommendation H.323 (02/98)
`
`vii
`
`Petitioner Apple Inc. - Ex. 1040, p. 9
`
`

`
`Petitioner Apple Inc. - Ex. 1040, p. 10
`
`

`
`
`
`Recommendation H.323
`
`PACKET-BASED MULTIMEDIA COMMUNICATIONS SYSTEMS
`(revised in 1998)
`
`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, Intra-Networks, and Inter-
`Networks (including the Internet). They also include dial up connections or point-to-point
`connections over the GSTN or ISDN which use an underlying packet based transport such as PPP.
`These networks may consist of a single network segment, or they may have complex topologies
`which incorporate many network segments interconnected by other communications links.
`This Recommendation describes the components of an H.323 system. This includes Terminals,
`Gateways, Gatekeepers, Multipoint Controllers, Multipoint Processors, and Multipoint Control
`Units. Control messages and procedures within this Recommendation define how these components
`communicate. Detailed descriptions of these components are contained in clause 6.
`H.323 terminals provide audio and optionally video and data communications capability in
`point-to-point or multipoint conferences. Interworking with other H-series terminals, GSTN or
`ISDN voice terminals, or GSTN or ISDN data terminals is accomplished using Gateways. See
`Figure 1. Gatekeepers provide admission control and address translation services. Multipoint
`Controllers, Multipoint Processors and Multipoint Control Units provide support for multipoint
`conferences.
`The scope of H.323 does not include the network interface, the physical network, or the transport
`protocol used on the network. Examples of these networks include but are not limited to:
`–
`Ethernet (IEEE 802.3);
`–
`Fast Ethernet (IEEE 802.3u);
`–
`FDDI;
`–
`Token Ring (IEEE 802.5);
`–
`ATM.
`
`
`
`
`
`Recommendation H.323 (02/98)
`
`1
`
`Petitioner Apple Inc. - Ex. 1040, p. 11
`
`

`
`
`
`Scope of
`H.323
`
`H.323
`Terminal
`
`H.323
`MCU
`
`Packet Based Network
`
`(Note)
`
`H.323
`Gateway
`
`H.323
`Gatekeeper
`
`H.323
`Terminal
`
`H.323
`Terminal
`
`GSTN
`
`Guaranteed
`QOS
`LAN
`
`N-ISDN
`
`B-ISDN
`
`H.310
`terminal
`operating in
`H.321 mode
`
`V.70
`Terminal
`
`H.324
`Terminal
`
`Speech
`Terminal
`
`H.322
`Terminal
`
`Speech
`Terminal
`
`H.320
`Terminal
`
`H.321
`Terminal
`
`H.321
`Terminal
`
`NOTE – A gateway may support one or more of the GSTN, N-ISDN and/or B-ISDN connections.
`
`T1604210-97
`
`
`
`Figure 1/H.323 – Interoperability of H.323 terminals
`
`Normative references
`2
`The following ITU-T Recommendations and other references contain provisions which, through
`reference in this text, constitute provisions of this Recommendation. At the time of publication, the
`editions indicated were valid. All Recommendations and other references are subject to revision; all
`users of this Recommendation are therefore encouraged to investigate the possibility of applying the
`most recent edition of the Recommendations and other references listed below. A list of the currently
`valid ITU-T Recommendations is regularly published.
`ITU-T Recommendation H.225.0 (1998), Call signalling protocols and media stream
`[1]
`packetization for packet based multimedia communication systems.
`ITU-T Recommendation H.245 (1998), Control protocol for multimedia communication.
`CCITT Recommendation G.711 (1988), Pulse Code Modulation (PCM) of voice
`frequencies.
`CCITT Recommendation G.722 (1988), 7 kHz audio-coding within 64 kbit/s.
`ITU-T Recommendation G.723.1 (1996), Speech coders: Dual rate speech coder for
`multimedia communications transmitting at 5.3 and 6.3 kbit/s.
`
`[4]
`[5]
`
`[2]
`[3]
`
`2
`
`Recommendation H.323 (02/98)
`
`Petitioner Apple Inc. - Ex. 1040, p. 12
`
`

`
`
`
`[6]
`
`[7]
`
`[8]
`
`[9]
`[10]
`[11]
`
`[12]
`
`[13]
`
`[14]
`
`[15]
`
`[16]
`
`[17]
`
`[18]
`
`[19]
`
`[20]
`
`[21]
`
`[22]
`
`[23]
`[24]
`
`[25]
`
`[26]
`
`[27]
`[28]
`
`CCITT Recommendation G.728 (1992), Coding of speech at 16 kbit/s using low-delay code
`excited linear prediction.
`ITU-T Recommendation G.729 (1996), Coding of speech at 8 kbit/s using Conjugate
`Structure Algebraic-Code-Excited Linear-Prediction (CS-ACELP).
`ITU-T Recommendation H.261 (1993), Video codec for audiovisual services at p ×
` 64 kbit/s.
`ITU-T Recommendation H.263 (1996), Video coding for low bit rate communication.
`ITU-T Recommendation T.120 (1996), Data protocols for multimedia conferencing.
`ITU-T Recommendation H.320 (1997), Narrow-band visual telephone systems and terminal
`equipment.
`ITU-T Recommendation H.321 (1996), Adaptation of H.320 visual telephone terminals to
`B-ISDN environments.
`ITU-T Recommendation H.322 (1996), Visual telephone systems and terminal equipment
`for local area networks which provide a guaranteed quality of service.
`(1996), Terminal
`for
`low bit rate multimedia
`ITU-T Recommendation H.324
`communication.
`ITU-T Recommendation H.310 (1996), Broadband audiovisual communication systems and
`terminals.
`ITU-T Recommendation Q.931 (1993), ISDN user-network interface layer 3 specification
`for basic call control.
`ITU-T Recommendation Q.932 (1993), Generic procedures for the control of ISDN
`supplementary services.
`ITU-T Recommendation Q.950 (1997), Supplementary services protocols, structure and
`general principles.
`technology – Universal Multiple-Octet Coded
`ISO/IEC 10646-1:1993, Information
`Character Set (USC) – Part 1: Architecture and Basic Multilingual Plane.
`ITU-T Recommendation E.164 (1997), The international public telecommunication
`numbering plan.
`ITU-T Recommendation H.246 (1998), Interworking of H-Series multimedia terminals with
`H-Series multimedia terminals and voice/voiceband terminals on GSTN and ISDN.
`ITU-T Recommendation H.235 (1998), Security and encryption for H-Series (H.323 and
`other H.245 based) multimedia terminals.
`ITU-T Recommendation H.3321, H.323 extended for loosely-coupled conferences.
`ITU-T Recommendation H.450.1 (1998), Generic functional protocol for the support of
`supplementary services in H.323.
`ITU-T Recommendation I.363.5 (1996), B-ISDN ATM adaptation layer specification:
`Type 5 AAL.
`ITU-T Recommendation Q.2931 (1995), Digital subscriber signalling system No. 2 (DSS 2)
`– User-network interface (UNI) – Layer 3 specification for basic call/connection control.
`ITU-T Recommendation I.356 (1996), B-ISDN ATM layer cell transfer performance.
`ITU-T Recommendation I.371 (1996), Traffic control and congestion control in B-ISDN.
`
`____________________
`1 Presently at the stage of draft.
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`Recommendation H.323 (02/98)
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`3
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`Petitioner Apple Inc. - Ex. 1040, p. 13
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`[29]
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`[30]
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`[31]
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`[32]
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`ITU-T Recommendation I.371.1 (1997), Traffic control and congestion control in B-ISDN:
`Conformance definitions for ABT and ABR.
`ITU-T Recommendation Q.2961.2 (1997), Digital Subscriber Signalling System No. 2 –
`Additional traffic parameters: Support of ATM Transfer capability in the broadband bearer
`capability information element.
`ITU-T Recommendation H.224 (1994), A real time control protocol for simplex applications