`
`‘
`
`INTERNATIONAL TELECOMMUNICATION UNION
`
`ITU -T
`TELECOMMUNICATION
`STANDARDIZATION SECTOR
`OF ITU
`
`H.225.0
`02/98)
`<
`
`SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS
`
`Infrastructure of audiovisual services — Transmission
`
`multiplexing and synchronization
`
`
`
`Call signalling protocols and media stream
`packetization for packet-based multimedia
`communication systems
`
`ITU-T Recommendation H.225.0
`
`(Previously CCITT Recommendation)
`
`Petitioner Apple Inc. - Exhibit 1083, Cover
`
`Petitioner Apple Inc. - Exhibit 1083, Cover
`
`

`

`lTU—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
`
`H.10—H.19
`H.20—H.29
`
`H.30—H.39
`
`H.450—H.499
`
`Telephone-type circuits used for facsimile telegraphy
`Characteristics of data signals
`CHARACTERlSTlCS OF VISUAL TELEPHONE SYSTEMS
`
`INFRASTRUCTURE OF AUDIOVISUAL SERVICES
`
`, \Nysihxi :
`an 'fjsiowmuipféxjfig andynchromza
`Systems aspects
`Communication procedures
`
`Coding of moving video
`Related systems aspects
`
`Systems and terminal equipment for audiovisual services
`Supplementary services for multimedia
`
`,
`
`,
`
`y
`
`1
`
`H.40—H.49
`H.50—H.99
`H.100—H.199
`
`H.200—H.219
`
`« 33
`H.§§O—H.239
`H.240—H.259
`
`H.260—H.279
`H.280—H.299
`
`H.300—H.399
`
`Forfurther details, please refer to ITU—T List ofRecommendations.
`
`Petitioner Apple Inc. - Exhibit 1083, Cover 2
`
`Petitioner Apple Inc. - Exhibit 1083, Cover 2
`
`

`

`ITU-T RECOMMENDATION H.225.0
`
`CALL SIGNALLING PROTOCOLS AND MEDIA STREAM PACKETIZATION
`FOR PACKET-BASED MULTIMEDIA COMMUNICATION SYSTEMS
`
`Summary
`
`This Recommendation covers the technical requirements for narrow-bandvisual telephone services
`defined in H.200/AV.120—series Recommendations, in those situations where the transmission path
`includes one or more packet—based networks, each of which is configured and managed to provide a
`non-guaranteed Quality of Service (QOS) which is not equivalent to that of N-ISDN such that
`additional protection or recovery mechanisms beyond those mandated by Recommendation H.320
`need be provided in the terminals. It is noted that Recommendation H.322 addresses the use of some
`other LAN5 which are able to provide the underlying performance not assumed by the H.323/H.225.0
`Recommendations.
`
`This Recommendation describes how audio, video, data, and control information on a packet—based
`network can be managed to provide conversational services in H.323 equipment.
`
`Source
`
`ITU-T Recommendation H.225.0 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.
`
`Recommendation H.225.0
`
`(02/98)
`
`i
`
`Petitioner Apple Inc. - Exhibit 1083, p. i
`
`Petitioner Apple Inc. - Exhibit 1083, p. i
`
`

`

`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.
`
`the expression "Administration" is used for conciseness to indicate both a
`In this Recommendation,
`telecommunication administration and a recognized operating agency.
`
`NOTE
`
`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 not 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.
`
`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.
`
`© ITU 1999
`
`ii
`
`Recommendation H.225.0
`
`(02/98)
`
`Petitioner Apple Inc. - Exhibit 1083, p. ii
`
`Petitioner Apple Inc. - Exhibit 1083, p. ii
`
`

`

`5.1
`
`5.2
`
`6.1
`
`6.2
`
`7.1
`
`7.2
`
`7.3
`
`CONTENTS
`
`Scope ..........................................................................................................................
`
`References ..................................................................................................................
`
`Definitions ..................................................................................................................
`
`Conventions ................................................................................................................
`
`Abbreviations .............................................................................................................
`
`General abbreviations .................................................................................................
`
`RAS message abbreviations .......................................................................................
`
`Packetization and synchronization mechanism ..........................................................
`
`General approach........................................................................................................
`
`Use of RTP/RTCP ......................................................................................................
`
`6.2.1
`
`Audio .............................................................................................................
`
`6.2.2 Video messages .............................................................................................
`
`6.2.3 Data messages ...............................................................................................
`
`H.225.0 message definitions ......................................................................................
`
`Use of Q.931 messages ..............................................................................................
`
`Common Q.931 Information Elements ......................................................................
`
`7.2.1 Header Information Elements .......................................................................
`
`7.2.2 Message-specific information elements ........................................................
`
`Q.931 message details ................................................................................................
`
`7.3.1 Alerting .........................................................................................................
`
`7.3.2
`7.3.3
`
`Call Proceeding .............................................................................................
`Connect .........................................................................................................
`
`7.3.4
`
`Connect Acknowledge ..................................................................................
`
`7.3.5 Disconnect .....................................................................................................
`
`7.3.6 User Information ...........................................................................................
`
`7.3.7
`7.3.8
`
`Progress .........................................................................................................
`Release ..........................................................................................................
`
`7.3.9
`
`Release Complete ..........................................................................................
`
`7.3.10 Setup ..............................................................................................................
`
`7.3.11 Setup Acknowledge ......................................................................................
`
`7.3.12 Status .............................................................................................................
`
`7.3.13 Status Inquiry ................................................................................................
`
`7.4
`
`Q.932 message details ................................................................................................
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`Recommendation H.225.0
`
`(02/98)
`
`iii
`
`Petitioner Apple Inc. - Exhibit 1083, p. iii
`
`Petitioner Apple Inc. - Exhibit 1083, p. iii
`
`

`

`7.5
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`7.6
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`7.7
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`7.8
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`7.9
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`7.10
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`7.11
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`7.12
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`7.13
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`7.14
`
`7.15
`
`7.4.1
`
`Facility...........................................................................................................
`
`7.4.2 Notify ............................................................................................................
`
`7.4.3 Other messages..............................................................................................
`
`Q.931 timer values .....................................................................................................
`
`H.225 .0 common message elements ..........................................................................
`
`Required Support of RAS messages ..........................................................................
`
`Terminal and Gateway Discovery messages ..............................................................
`
`7.8.1 GatekeeperRequest (GRQ)............................................................................
`
`7.8.2 GatekeeperConfirm (GCF)............................................................................
`
`7.8.3 GatekeeperReject (GRJ)................................................................................
`
`Terminal and Gateway Registration messages ...........................................................
`
`7.9.1
`
`7.9.2
`
`7.9.3
`
`RegistrationRequest (RRQ) ..........................................................................
`
`RegistrationConfirm (RCF) ..........................................................................
`
`RegistrationReject (RRJ) ..............................................................................
`
`Terminal/Gatekeeper Unregistration messages ..........................................................
`
`7.10.1 UnregistrationRequest (URQ) .......................................................................
`
`7.10.2 UnregistrationConfmn (UCF) .......................................................................
`
`7.10.3 UnregistrationReject (URJ)...........................................................................
`
`Terminal to Gatekeeper Admission messages............................................................
`
`7.11.1 AdmissionRequest (ARQ) ............................................................................
`
`7.1 1.2 AdmissionConfinn (ACF) ............................................................................
`
`7.11.3 AdmissionReject (ARJ) ................................................................................
`
`Terminal to gatekeeper requests for changes in bandwidth .......................................
`
`7.12.1 BandwidthRequest (BRQ) ............................................................................
`
`7.12.2 BandwidthConfirm (BCF) ............................................................................
`
`7.12.3 BandwidthReject (BRJ) ................................................................................
`
`Location Request messages ........................................................................................
`
`7.13.1 LocationRequest (LRQ) ................................................................................
`
`7.13.2 LocationConfirm (LCF) ................................................................................
`
`7.13.3 LocationReject (LRJ) ....................................................................................
`
`Disengage messages ...................................................................................................
`
`7.14.1 DisengageRequest (DRQ) .............................................................................
`
`7.14.2 DisengageConfirm (DCF) .............................................................................
`
`7.14.3 DisengageReject (DRJ) .................................................................................
`
`Status Request messages ............................................................................................
`
`7.15.1
`
`InfoRequest (IRQ) .........................................................................................
`
`7.15.2 InfoRequestResponse (IRR)..........................................................................
`
`iv
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`Recommendation H.225.0
`
`(02/98)
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`Petitioner Apple Inc. - Exhibit 1083, p. iv
`
`Petitioner Apple Inc. - Exhibit 1083, p. iv
`
`

`

`7.15.3 InfoRequestAck (IACK) ...............................................................................
`
`7.15.4 InfoRequcstNak (INAK) ...............................................................................
`
`7.16
`
`Non-Standard message ...............................................................................................
`
`7.17 Message Not Understood ...........................................................................................
`
`7.18
`
`Gateway Resource Availability messages ..................................................................
`
`7.18.1 ResourcesAvailableIndicate (RAI)................................................................
`
`7.18.2 ResourcesAvaiIableConfirm (RAC) .............................................................
`
`7.19 MS timers and Request in Progress (RLP) ................................................................
`
`8
`
`8.1
`
`8.2
`
`8.3
`
`8.4
`
`8.5
`
`8.6
`
`Mechanisms for maintaining QOS .............................................................................
`
`General approach and assumptions ............................................................................
`
`Use of RTCP in measuring QOS ................................................................................
`
`8.2.1
`
`Sender reports ................................................................................................
`
`8.2.2
`
`Receiver Reports ...........................................................................................
`
`Audio/Video jitter procedures ....................................................................................
`
`Audio/Video Skew Procedures ..................................................................................
`
`Procedures for maintaining QOS ...............................................................................
`
`Echo Control ..............................................................................................................
`
`Annex A — RTP/RTCP ............................................................................................................
`
`A. 1
`
`A2
`
`Introduction ................................................................................................................
`
`RTP use scenarios ......................................................................................................
`
`Simple multicast audio conference ...............................................................
`A21
`A22 Audio and video conference..........................................................................
`
`A23 Mixers and translators ...................................................................................
`
`A.3
`
`Definitions ..................................................................................................................
`
`A4
`
`A.5
`
`Byte order, alignment and time format.......................................................................
`
`RTP data transfer protocol .........................................................................................
`A51 RTP fixed header fields .................................................................................
`
`A52 Multiplexing RTP sessions ...........................................................................
`
`A.5.3
`
`Profile—specific modifications to the RTP header .........................................
`
`A6
`
`RTP Control Protocol (RTCP) ...................................................................................
`
`A61 RTCP packet format......................................................................................
`A62 RTCP transmission interval ..........................................................................
`
`A.6.2.2 Allocation of source description bandwidth ...............................................................
`
`A63 Sender and receiver reports ...........................................................................
`
`A64 SDES: Source Description RTCP packet......................................................
`
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`
`(02/98)
`
`v
`
`Petitioner Apple Inc. - Exhibit 1083, p. V
`
`Petitioner Apple Inc. - Exhibit 1083, p. v
`
`

`

`A65 BYE: Goodbye RTCP packet........................................................................
`
`A.6.6 APP: Application—defined RTCP packet.......................................................
`
`A7
`
`RTP translators and mixers ........................................................................................
`
`A71 General description .......................................................................................
`
`A72 RTCP processing in translators .....................................................................
`
`A.7.3 RTCP Processing in mixers ..........................................................................
`
`A74 Cascaded mixers ...........................................................................................
`
`A.8
`
`SSRC identifier allocation and use .............................................................................
`
`A81 Probability of Collision .................................................................................
`
`A82 Collision resolution and loop detection ........................................................
`
`A9
`
`Security .......................................................................................................................
`
`A. 10
`
`RTP over network and transport protocols.................................................................
`
`A. 11
`
`Summary of protocol constants ..................................................................................
`
`A.11.1 RTCP packet types ........................................................................................
`
`A.11.2 SDES types....................................................................................................
`
`A. 12
`
`RTP profiles and payload format specifications ........................................................
`
`A. 13
`
`Algorithms ..................................................................................................................
`
`A. 14
`
`Bibliography ...............................................................................................................
`
`Annex B — RTP Profile ............................................................................................................
`
`B. 1
`
`B.2
`
`B3
`
`B4
`
`B5
`
`B6
`
`B7
`
`Introduction ................................................................................................................
`
`RTP and RTCP packet forms and protocol behaviour ...............................................
`
`Payload types ..............................................................................................................
`
`Audio ..........................................................................................................................
`
`B.4.1
`
`Encoding-independent recommendations .....................................................
`
`B.4.2 Guidelines for sample-based audio encodings ..............................................
`
`B.4.3 Guidelines for frame—based audio encodings ................................................
`
`B.4.4 Audio encodings............................................................................................
`
`Video ..........................................................................................................................
`
`Payload type definitions .............................................................................................
`
`Port Assignment .........................................................................................................
`
`Annex C — RTP payload format for H.261 video streams.......................................................
`
`C. 1
`
`02
`
`Introduction ................................................................................................................
`
`Structure of the packet stream ....................................................................................
`
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`vi
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`Recommendation H.225.0
`
`(02/98)
`
`Petitioner Apple Inc. - Exhibit 1083, p. Vi
`
`Petitioner Apple Inc. - Exhibit 1083, p. vi
`
`

`

`021 Overview of Recommendation H.261 ...........................................................
`
`C22 Considerations for packetization ...................................................................
`
`C3
`
`Specification of the packetization scheme .................................................................
`
`C31 Usage of RTP ................................................................................................
`
`C.3.2 Recommendations for operation with hardware codecs ...............................
`
`C.3.3
`
`Packet loss issues ..........................................................................................
`
`C.3.4 Use of optional H.261—specific control packets ............................................
`
`C35 Control packets definition .............................................................................
`
`C4
`
`Bibliography ...............................................................................................................
`
`Annex D — RTP payload format for H.261A Video streams....................................................
`
`D. 1
`
`Introduction ................................................................................................................
`
`D2
`
`H.261A RTP packetization ........................................................................................
`
`Annex E - Video packetization ...............................................................................................
`
`Annex F — Audio packetization ...............................................................................................
`
`F .1
`
`F2
`
`F. 3
`
`F.4
`
`G.723.1 .......................................................................................................................
`
`6.728 ..........................................................................................................................
`
`G. 729 ..........................................................................................................................
`
`Silence suppression ....................................................................................................
`
`Annex G - Gatekeeper-to-gatekeeper communication............................................................
`
`Annex H — H.225.0 Message Syntax (ASN.1) ........................................................................
`
`Appendix I — RTP/RTCP algorithms .......................................................................................
`
`Appendix II — RTP profile .......................................................................................................
`
`Appendix III - H.261 packetization ......................................................'..................................
`
`Appendix IV — H.225 .0 operation on different packet-based network protocol stacks...........
`
`IV. 1
`
`TCP/IP/UDP ...............................................................................................................
`
`IV.1.1 Discovering the gatekeeper ...........................................................................
`
`IV.1.2 Endpoint-to-endpoint communications .........................................................
`
`IV.2
`
`SPX/IPX .....................................................................................................................
`
`IV.2.1 Discovering the gatekeeper ...........................................................................
`
`IV.2.2 Endpoint-to—endpoint communication ..........................................................
`
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`Recommendation H.225.0
`
`(02/98)
`
`vii
`
`Petitioner Apple Inc. - Exhibit 1083, p. Vii
`
`Petitioner Apple Inc. - Exhibit 1083, p. vii
`
`

`

`Recommendation H.225.0
`
`CALL SIGNALLING PROTOCOLS AND MEDIA STREAM PACKETIZATION
`FOR PACKET-BASED MULTIMEDIA COMMUNICATION SYSTEMS
`
`(revised in 1998)
`
`The ITU-T,
`
`considering
`
`the widespread adoption of and the increasing use of Recommendation H.320 for videophony and
`videoconferencing services over networks conforming to the N-ISDN characteristics specified in the
`I-series Recommendations,
`
`appreciating
`
`the desirability and benefits of enabling the above services to be carried, wholly or in part, over Local
`Area Networks while also maintaining the capability of interworking with H.320 terminals,
`
`and noting
`
`the characteristics and performances of the many types of Local Area Network which are of potential
`interest,
`
`recommends
`
`that systems and equipment meeting the requirements of Recommendations H.322 or H.323 are
`utilized to provide these facilities.
`
`1
`
`Scope
`
`This Recommendation describes the means by which audio, Video, data, and control are associated,
`coded, and packetized for transport between H.323 equipment on a packet-based network. This
`includes the use of an H.323 gateway, which in turn may be connected to H.320, H.324, or
`H.310/H.321 terminals on N-ISDN, GSTN, or B-ISDN respectively. The equipment descriptions and
`procedures are described in Recommendation H.323 while this Recommendation covers protocols
`and message formats. Communication via an H.323 gateway to an H.322 gateway for guaranteed
`Quality of Service (QOS) LANs and thus to H.322 endpoints is also possible.
`
`This Recommendation is intended to operate over a variety of different packet-based networks,
`including IEEE 802.3, Token Ring, etc. Thus, this Recommendation is defined as being above the
`Transport
`layer such as TCP/IP/UDP, SPX/IPX, etc. Specific profiles for particular transport
`protocol suites are included in Appendix IV. Thus, the scope ofH.225.0 communication is between
`H.323 entities on the same packet-based network, using the same transport protocol. This packet-
`based network may be a single segment or ring, or it logically could be an enterprise data network
`comprising multiple packet-based networks bridged or routed to create one interconnected network.
`It should be emphasized that operation of H.323 terminals over the entire Internet, or even several
`connected packet-based networks may result in poor performance. The possible means by which
`quality of service might be assured on this packet-based network, or on the Internet in general is
`beyond the scope of this Recommendation. However, this Recommendation provides a means for the
`user of H.323 equipment to determine that quality problems are the result of packet—based network
`congestion, as well as procedures for corrective actions. It is also noted that the use of multiple
`
`Recommendation H.225.0
`
`(02/98)
`
`1
`
`Petitioner Apple Inc. - Exhibit 1083, p. l
`
`Petitioner Apple Inc. - Exhibit 1083, p. 1
`
`

`

`H.323 gateways connected over the public ISDN network is a straightforward method for increasing
`quality of service.
`
`Recommendation H.323 and this Recommendation are intended to extend Recommendations H.320
`and H.221 connections onto the non-guaranteed QOS packet—based network environment
`conferences. As such the primary conference model1 is one with size in the range of a few
`participants to a few thousand, as opposed to large-scale broadcast operations, with strong admission
`control, and tight conference control.
`
`This Recommendation makes use of (RTP/RTCP) Real-time Transport Protocol/Real-Time
`Transport Control Protocol for media stream packetization and synchronization for all underlying
`packet—based networks (see Annexes A, B, and C). Please note that the usage of RTP/RTCP as
`specified in this Recommendation is not tied in any way to the usage of TCP/lP/UDP. This
`Recommendation assumes a call model where initial signalling on a non—RTP transport address is
`used for call establishment and capability negotiation (see Recommendations H.323 and H.245),
`followed by the establishment of one or more RTP/RTCP connections. This Recommendation
`contains details on the usage of RTP/RTCP.
`
`In Recommendation H.221, audio, video, data, and control are multiplexed into one or more
`synchronized physical SCN calls. On the packet-based network side of an H.323 call, none of these
`concepts apply. There is no need to carry from the SCN side the H.221 concept of a P*64 kbit/s call,
`e.g. 2 by 64 kbit/s, 3 by 64 kbit/s, etc. Thus, on the packet—based network side, for example, there are
`only single "connection" calls with a maximum rate limited to 128 kbit/s, not 2*64 kbit/s fixed rate
`calls. Another example has single "connection" packet-based network calls with a maximum rate
`limited to 384 kbit/s interworking with 6*64 kbit/s on the WAN sidez. The primary rationale of this
`approach is to put complexity in the gateway rather than the terminal and to avoid extending onto the
`packet-based network features of H.320 that are tightly tied to ISDN unless this is necessary.
`
`In general, H.323 terminals are not aware directly of the H.320 transfer rate while interworking
`through an H.323 gateway; instead, the gateway uses H.245 FlowControlCommand messages to
`limit the media rate on each logical channel in use to that allowed by the H.221 multiplex. The
`gateway may allow the packet—based network side video rates to substantially underrun the WAN
`side rates (or the reverse) though the usage of a rate reducing function and H.261 fill frames; the
`details of
`such operations
`are beyond the
`scope of Recommendation H.323
`and this
`Recommendation. Note that the H.323 terminal is indirectly aware of the H.320 transfer rates via the
`video maximum bit rate fields in Recommendation H.245 and shall not transmit at rates that exceed
`these rates.
`
`This Recommendation is designed so that, with an H.323 gateway, interoperability with H.320
`(1990), H.320 (1993), and H.320 (1996) terminals is possible. However, some features of this
`Recommendation may be directed toward allowing enhanced operations with future versions of
`
`1 An optional broadcast only conference model is under consideration; of necessity the broadcast model does
`not provide tight admissions or conference control.
`
`2 Note that Video and data rates on the LAN side must match the video and data rates in the SCN side H.320
`
`multiplex; the audio and control rates are not required to match. Stated another way one would normally
`expect that, using H.245 flow control, the LAN/SCN gateway will force the video and data rates to fit into
`the H.221 SCN multiplex. However, since audio may be transcoded in the gateway often, one will
`frequently find that the LAN audio rate and the SCN rate do not match. Also there should be no
`expectation that the H.221 bit rate for control (800 bit/s) wi