1、INTERNATIONAL TELECOMMUNICATION UNION ITU=T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU H.248 Annex M4 (on200 1 ) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS Infrastructure of audiovisual services - Communication procedures Gateway control protocol Annex M4: H.248 packages for H.323 and H.324 i
2、n terwor king ITU-T Recommendation H.248 - Annex M4 (Formerly CCIT Recommendation) INTERNATIONAL TELECOMMUNICATION UN ION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU H.248 Annex M4 (07/2001) SERIES H: AUDIOVISUAL AND MULTIMEDIA SYSTEMS Infrastructure of audiovisual services - Communication
3、 procedures Gateway control protocol Annex M4: H.248 packages for H.323 and H.324 interworking ITU-T Recommendation H.248 - Annex M4 (Formerly CCIlT Recommendation) ITU-T H-SERIES RECOMMENDATIONS AUDIOVISUAL AND MULTIMEDIA SYSTEMS CHARACTERISTICS OF VISUAL TELEPHONE SYSTEMS INFRASTRUCTURE OF AUDIOVI
4、SUAL SERVICES General Transmission multiplexing and synchronization Systems aspects Coding of moving video Related systems aspects - I _I Communication procedures -_ SYSTEMS AND TERMINAL EQUIPMENT FOR AUDIOVISUAL SERVICES SUPPLEMENTARY SERVICES FOR MULTIMEDIA H. 100-H. 199 H.200-H.219 H.220-H.229 H.
5、230-H.239 H.240-H.259 H.260-H.279 H.280-H.299 H.300-H.399 H.450-H.499 - _- For further details, please refer to the list of ITU-T Recommendations. ITU-T Recommendation H.248 Gateway control protocol ANNEX M4 H.248 packages for H.323 and H.324 interworking Summary This annex defines several H.248 pac
6、kages that are intended for Media Gateways designed to support interworking between H.323 terminals and H.324 terminals. More specifically, this Annex contains: package “h324“ for creating terminations supporting H.324, package “h245“ for creating terminations supporting H.245 channels for H.324 cal
7、ls, package “h323bc“ for creating terminations supporting H.245 channels for H.323 calls, package “h245com“ for the communication of H.245 commands between a MGC and MG, and package “h245ind“ for the communication of H.245 indications. Source Annex M4 to ITU-T Recommendation H.248 was prepared by IT
8、U-T Study Group 16 (2001-2004) and approved under the WTSA Resolution 1 procedure on 29 July 2001. ITU-T H.248/Annex M4 (07/2001) I FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standard
9、ization 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
10、 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
11、-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 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 ITU dr
12、aws 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
13、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 repres
14、ent the latest information and are therefore strongly urged to consult the TSB patent database. o mu 2001 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
15、writing from ITU. 11 ITU-T H.248/Annex M4 (07/2001) CONTENTS Annex M4 . H.248 packages for H.323 and H.324 interworking . M4.1 M4.2 M4.3 M4.4 M4.5 M4.6 M4.7 M4.8 Introduction Scope . References M4.3.1 Normative references . M4.3.2 Informative reference . H324 Package . M4.4.1 Properties M4.4.2 Event
16、s M4.4.3 Signals . M4.4.4 Statistics M4.4.5 Procedures . H245 Package . M4.5.1 Properties M4.5.3 Signals . M4.5.4 Statistics M4.5.5 Procedures . H323 Bearer Control Package . M4.6.1 Properties M4.5.2 Events M4.6.2 Events M4.6.3 Signals . M4.6.4 Statistics M4.6.5 Procedures . H.245 Command Package .
17、M4.7.1 Properties M4.7.2 Events M4.7.3 Signals . M4.7.4 Statistics M4.7.5 Procedures . H.245 Indication package . M4.8.1 Properties M4.8.2 Events M4.8.3 Signals . M4.8.4 Statistics M8.4.5 Procedures . Page 1 1 1 1 2 2 2 3 6 6 6 6 7 7 8 11 11 11 11 12 12 13 13 13 13 14 15 15 15 15 15 16 16 16 16 16 I
18、TU-T H.248/Annex M4 (0712001) . U1 Page M4.9 Call flows . 16 M4.9.1 H.323-Annex Cm.324 interworking with H.245 in MG . 17 20 21 M4.9.2 H.323-Annex Cm.324 interworking with H.245 in MGC M4.9.3 Tunnelling of Annex Cm.324 bitstream iv ITU-T H.248/Annex M4 (07/2001) ITU-T Recommendation H.248 Gateway co
19、ntrol protocol ANNEX M4 H.248 packages for H.323 and H.324 interworking M4.1 Introduction This annex gathers packages for H.245, H.245 parameters specific to H-series audiovisual terminals, and Annex Cm.324 terminals for use with the H.248 gateway control protocol. The packages in this annex are in
20、conformance with clause 12m.248 package definition guidelines. M4.2 Scope This annex describes packages for the H.248 gateway control protocol related to interworking of H.323 and H.324 terminals, as follows: - - - - Package “h324“ for termination of H.324 bitstream on MGs. Package “h245“ for termin
21、ation of H.245 messages on MGs. Package “h323bc“ for H.245 parameters specific to H.323. Package “h245com“ for providing properties that allow the MGC to indicate to the MG that the MGC has sent or received an H.245 command. Package “h245ind“ for providing properties that allow the MGC to indicate t
22、o the MG that the MGC has sent or received an H.245 indication. With the terminations implementing “h324“, “h245com“ and “h245ind“ packages, the de-composed gateway may support H.324 communication with the H.245 control function in the MGC. In the H.324 and H.323 interworking scenario with this de-c
23、omposed gateway, H.245 control messages are terminated in the MGC (a backhaul is used between the MG and the MGC to transport H.245 messages between the MG and the MGC, on the H.324 side). The terminations for media on both H.324 and H.323 sides are managed by the MGC. With the terminations implemen
24、ting “h324“ and “h245“ packages, the de-composed gateway may support H.324 communication with H.245 control in the MG. In the H.324 and H.323 interworking scenario with this de-composed gateway, H.245 control messages from the H.324 side and the H.323 side are terminated in the “h245“ termination an
25、d in the “h323bc“ termination respectively, and are processed in the MG. The MG manages the logical channels for media. - M4.3 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. A
26、t the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed
27、below. A list of the currently valid ITU-T Recommendations is regularly published. ITU-T H.248IAnnex M4 (07/2001) 1 M4.3.1 Normative references ITU-T H.223 (2001), Multiplexing protocol for low bit rate multimedia communication. ITU-T H.245 (2001), Control protocol for multimedia communication. ITU-
28、T H.323 (2000), Packet-based multimedia communications systems. ITU-T H.324 (1998), Terminal for low bit-rate multimedia communication. ITU-T V.8 (2000), Procedures for starting sessions of data transmission over the public switched telephone network. ITU-T V.8 bis (2000), Procedures for the identif
29、ication and selection of common modes of operation between data circuit-terminating equipments (DCEs) and between data terminal equipments (DTEs) over the public switched telephone network and on leased point-to-point telephone-type circuits. ITU-T V.34 (1998), A modem operating at datu signalling r
30、ates of up to 33 600 bitls for use on the general switched telephone network and on leased point-to-point 2-wire telephone-type circuits. ITU-T V.42 (1996), Error-correcting procedures for DCEs using asynchronous-to-synchronous conversion. ITU-T V.42 bis ( 1990), Data compression procedures for data
31、 circuit-terminating equipment (DCE) using error correction procedures. ITU-T V. 140 (1 998), Procedures for establishing communication between two multiprotocol audiovisual terminals using digital channels at a multiple of 64 or 56 kbitls. ITU-T X.691 (1997), Information technology - ASNA encoding
32、rules: Specification of Packed Encoding Rules (PER). M4.3.2 Informative reference - RFC 2960 (2000), Stream Control Transmission Protocol. M4.4 H324 Package Package Name: H.324 PackageID : h324, (0x002) Version: 1 Extends: None Descript ion: This package is defined to support terminations for calls
33、using ITU-T H.324. The transport mechanism or bearer channel will be different for each environment where the package is used. Figure M4-1 shows the functional view of a H.324 multimedia call and the MGC control points defined in the H.324 package. In ITU-T H.324, there are three communication modes
34、 defined according to the underlying network: a PSTN mode defined in ITU-T H.324 main body (H.324P), a mobile network mode defined in Annex Cm.324 (H.324M), and an ISDN mode defined in Annex Dm.324 (H.3241). One of these communication modes shall be selected when the termination implementing the H.3
35、24 package is invoked by the MGC. 2 ITU-T H.248/Annex M4 (07/2001) In version 1 of the H.324 package, only the functionalities required of the H.324M mode are defined. The functionalities for H.324P and H.3241 are FFS, and will be defined in version 2 or later. Control point defined in H.324 package
36、 H.245 messages _ CCSRL H.223 bitstream without being dernultiplexed I, Audio Video I I I I l I TI 609880-01 L. H.324M H.3241 H.324P Figure M4-llH.248 - Control point defined in H.324 package M4.4.1 Properties M4.4.1.1 Communication mode Property Name: Communication mode PropertyID: cmod (0x0001) Ty
37、pe: Enumeration Possible values: H324P (0x000 1) H324M (0x0002) Annex CM.324 (Mobile) H324I (0x0003) Annex Dm.324 (ISDN) H324 operating in the base PSTN mode using a V-series modem Defined in: Terminations tate Characteristics: Readwrite Description: This property indicates the communication mode to
38、 be followed by the termination. ITU-T H.24WAnnex M4 (07/2001) 3 M4.4.1.2 Highest Multiplexing Level Property Name: Highest Multiplexing level PropertyID: muxlv (0x0002) Type: Enumeration Possible values: LevelO (0x0001) H.223 level O defined in ITU-T H.223 Level 1 (0x0002) H.223 level 1 defined in
39、Annex M.223 Leve12 (0x0003) H.223 level 2 defined in Annex Bm.223 Level3 (0x0004) H.223 level 3 defined in Annex Cm.223 Defined in: Terminations tate Characteristics: Readwrite Description: This property indicates the highest level of H.223 multiplexing which can be used by the termination. The indi
40、cated level is used in the multiplex level initialization phase as defined in C.6m.324. The default value is LevelO. If the communication mode property is set to H324P or H324I, the value of the highest multiplexing level property shall be set to LevelO. M4.4.1.3 Demultiplex Property Name: Demultipl
41、ex Propert yID : demux (0x0003) Type: Boolean Possible values: TRUE (0x0001) H.223 multiplexed stream is demultiplexed FALSE (0x0000) H.223 multiplexed stream is not demultiplexed Defined in: LocalControl Characteristics: Readwrite Description: This property specifies the operation on the H.223 mult
42、iplexed stream received by the termination. If set to FALSE, the H.223 multiplexed stream is relayed to the other termination without being demultiplexed. If set to TRUE, each logical channel data is extracted fi-om the multiplexed stream, and is given to the appropriate termination. The default val
43、ue shall be TRUE. M4.4.1.4 Remote H.223 capability Property Name: Remote H.223 capability Propert yID : h223capr (0x0004) Type: OCTET STRING Possible values: This property indicates the value of the H.245 H223Capability structure encoded by applying the Packed Encoding Rules (PER) specified in ITU-T
44、 X.691. 4 ITU-T H.24WAnnex M4 (07/2001) Defined in: LocalControl Characteristics: ReadfWrite De script ion: This property indicates the remote endpoints capabilities specific to the H.223 multiplex capability. The MGC shall set the value of the h223capr property to the value of the H223Capability in
45、 the received H.245 message. M4.4.1.5 Incoming Multiplex Table Property Name: Incoming Multiplex Table Propert yID : muxtbl-in (0x0005) Type: OCTET STRING Possible values: This property indicates the value of H.245 MultiplexEntrySend message received by the MGC (see description for details). The Mul
46、tiplexEntrySend structure is encoded by applying PER. Defmed in: LocalControl Characteristics: Read /Write Description: This property indicates the H.223 multiplex table which associates each octet within an H.223 MUX-PDU with a particular logical channel number. Upon receipt of the MultiplexEntrySe
47、nd message from the remote endpoint, the MGC shall decide whether it confirms or rejects each multiplex table entry. The MGC shall create an equivalent multiplefintrysend message that contains only the entries that it confirmed to the remote H.324 terminal and the MGC shall send the created message
48、as the content of the muxtbl-in property so that the MG can perform the demultiplexing of the incoming H.223 MUX-PDUS. M4.4.1.6 Outgoing Multiplex Table Property Name: Outgoing Multiplex Table Propert yID : muxtbl-out (0x0006) Type: OCTET STRING Possible values: This property indicates the value of
49、H.245 MultiplexEntrySend message sent by the MGC (see description for details). The MultiplexEntrySend structure is encoded by applying PER. Defined in: LocalControl Characteristics : ReadfWrite Description: This property indicates the H.223 multiplex table which associates each octet within an H.223 MUX-PDU with a particular logical channel number. Upon receipt of the MultiplexEntrySendAck message from the remote endpoint, the MGC shall send multiplex table entries which are confirmed by the remote endpoint as the content of the muxtbl-out property. Thus the MG can pe
