1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T T.137TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (02/2000) SERIES T: TERMINALS FOR TELEMATIC SERVICES Virtual meeting room management for multimedia conferencing audiovisual control ITU-T Recommendation T.137 (Formerly CCITT Recommendation) Recommenda
2、tion T.137 (02/2000) i ITU-T RECOMMENDATION T.137 VIRTUAL MEETING ROOM MANAGEMENT FOR MULTIMEDIA CONFERENCING AUDIOVISUAL CONTROL Summary This Recommendation defines the functionality required to deliver a combined voice- and data-conferencing (audiographics) service; it is architected to deliver su
3、ch services using generic and extensible mechanisms that are independent of the underlying transports used for delivering the real-time media streams. In future revisions this scope is expected to broaden to cover all media services used within a conference. This protocol extends the Generic Confere
4、nce Control Recommendation (T.124), adding the capability to define and manage virtual meetings spaces within the GCC conference. It provides a means to seamlessly integrate all of the media components being used within a meeting. These virtual meeting spaces can be regarded as representing meeting
5、rooms where audio, video and data communication can take place. The functionality provides support for a number of virtual meeting scenarios including round-table meetings, informal meeting spaces and conferences with audiences. The protocol provides inherent support for multi-room scenarios. The pr
6、otocol will find application in support of enhanced audio conferencing and audiographics conferencing services. The aim is to provide an holistic approach to the management of the meeting room involving multiple media, while providing the flexibility to adapt individual meeting rooms in response to
7、user requirements. The object of standardizing this functionality is to provide a basis for interoperability between client applications and conferencing services. Source ITU-T Recommendation T.137 was prepared by ITU-T Study Group 16 (1997-2000) and was approved under the WTSC Resolution No. 1 proc
8、edure on 17 February 2000. Recommendation T.137 (02/2000) iiFOREWORD 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 respons
9、ible 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 I
10、TU-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-Ts purview, the necessary standar
11、ds 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 possibili
12、ty 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 R
13、ecommendation 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 inf
14、ormation and are therefore strongly urged to consult the TSB patent database. Ge3 ITU 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 writing from th
15、e ITU. Recommendation T.137 (02/2000) iii CONTENTS Page 1 Scope. 1 2 References. 2 3 Definitions 3 4 Abbreviations 4 5 Conventions 5 6 Overview. 5 7 Meeting room management Components 6 7.1 Virtual meeting rooms 6 7.2 The lobby 7 7.3 The conference framework . 7 7.4 MRM rosters. 8 7.4.1 The MRM conf
16、erence roster 8 7.4.2 The MRM room roster. 8 7.4.3 Roster operation. 8 7.5 Meeting room types 8 7.6 Meeting room modes 9 7.7 Room Hierarchies and relationships . 9 7.7.1 Room access regimes. 9 7.7.2 Room entry regimes. 9 7.7.3 Room state . 10 7.8 Classes of participation in a conference 10 7.8.1 MRM
17、 observers . 11 7.8.2 MRM participants 11 7.8.3 MRM administrators 12 7.8.4 MRM groups 12 7.9 MRM conference services 13 7.10 Starting an MRM conference 13 7.10.1 Private side communication. 14 7.10.2 Relationship between meeting rooms and data sessions . 14 7.10.3 Role and relationship to the GCC c
18、onductor. 15 7.10.4 MRM management nodes 15 7.10.5 Proxying MRM functionality. 15 8 T.137 infrastructure management functionality 15 8.1 Use Of MCS channels. 15 8.2 Static channels 15 Recommendation T.137 (02/2000) ivPage 8.3 Dynamic channels. 16 9 MRM infrastructure management service definition 16
19、 9.1 Summary of MRM abstract services. 16 9.2 Establishing the MRM Top provider 19 9.3 MRM conference framework 19 9.3.1 Description of abstract services. 24 9.4 The MRM rosters 26 9.4.1 Description of abstract services. 27 9.5 Meeting rooms 32 9.5.1 Description of abstract services. 33 9.6 MRM grou
20、ps. 39 9.6.1 Specifying groups in the framework 39 9.6.2 Specifying groups within an active room 39 9.6.3 Description of abstract services. 39 9.7 T.120 sessions. 43 9.7.1 Description of abstract services. 43 9.8 MRM room roles 44 9.8.1 Room role permissions Specification. 46 9.8.2 Room Roles Descri
21、ption of abstract services . 48 9.8.3 The chair role. 57 9.8.4 Accessing pre-defined roles. 58 9.8.5 Asking a role holder for permission to Act . 58 9.9 Permission to take action (Incorporating floor control) 58 9.9.1 Description of abstract services. 58 9.10 Conference media controls and indication
22、s 64 9.10.1 Description of abstract services. 64 9.11 MRM media services 71 9.11.1 Service events 71 9.11.2 Audio Bridging Service . 72 9.12 Audio Mixer management 72 9.12.1 Description of abstract services. 72 10 MRM protocol definition 79 10.1 MRM node types. 79 10.2 Launching MRM. 79 10.3 Determi
23、ning the MRM top provider. 79 10.4 MRM initialization and start-up . 79 10.5 General Operation. 82 Recommendation T.137 (02/2000) v 10.6 Framework PDUs 83 10.7 Roster PDUs . 85 10.7.1 Roster Reporting 85 10.7.2 Updating participants roster information. 87 10.8 Room PDUs 88 10.8.1 Creating an MRM Roo
24、m . 88 10.8.2 Entering An MRM Room 90 10.8.3 Invitation to an MRM Room . 92 10.8.4 Creating a group 92 10.9 T.120 Session Association 95 10.10 Room role PDUs. 95 10.10.1 Assigning an MRM role 95 10.10.2 Relinquishing an MRM role 97 10.10.3 Asking for an MRM role . 98 10.10.4 Passing An MRM Role to a
25、nother Room Participant 98 10.10.5 Changing role permissions 100 10.11 Permission PDUs 100 10.11.1 Asking the chair for permission to take action 100 10.11.2 Relinquishing Permission 101 10.11.3 Chair grants permission . 102 10.12 Source Identification PDUs 102 10.13 Indication PDUs 103 10.13.1 Noti
26、fication of privacy. 103 10.14 Service Command PDUs 104 10.15 Audio Management PDUs 105 10.15.1 Service initialization 105 10.15.2 Audio Mixer Setup 105 10.15.3 Audio Mixer status reporting. 106 10.15.4 Inviting Audio-Only participation . 107 10.15.5 Ejecting an-Audio-Only participant. 108 11 ASN.1
27、Definitions 109 12 Requirements for running MRM 129 12.1 Summary of GCC services required by MRM 129 12.2 Summary of use of the Multipoint Communication Service 129 12.2.1 MCS services. 129 12.2.2 MCS channels used by MRM 130 12.2.3 MCS Tokens used by MRM 131 12.2.4 Encoding of PDUs in MCS primitive
28、s 131 Recommendation T.137 (02/2000) 1Recommendation T.137 VIRTUAL MEETING ROOM MANAGEMENT FOR MULTIMEDIA CONFERENCING AUDIOVISUAL CONTROL 1 Scope This Recommendation provides extensions to the Generic Conference Control functionality to support the specification and management of virtual meeting sp
29、aces (meeting rooms) within a conference. It provides a cohesive and uniform approach to the management of all media used within the meeting room irrespective of the underlying transport and media encodings used.1This work is expected to find application in the provision of commercial conference ser
30、vices. This Recommendation defines procedures for arbitrating use of real-time media services such as telephony and video streaming2, for advertising those services to participating nodes, and for managing and controlling those services once activated. This Recommendation specifies mechanisms for mu
31、ltimedia capability reporting at the start of and during communications, and defines procedures for arbitrating access to, and configuring the infrastructure in support of, the services. This Recommendation supports conferences in which data communication is established first as well as conferences
32、in which audio communications are established first. The provisions of this Recommendation are independent of the underlying network(s) and the content of real-time streams that traverse those networks. Furthermore, this Recommendation provides the possibility for different types of multimedia syste
33、m to co-exist within the same conference and for those systems to be controlled in a uniform manner. This Recommendation defines a Conference Server that takes responsibility for the running of the MRM Conference and a service access channel for communication between the clients and server. The MRM
34、protocol places minimal implementation burden on client terminals with most of the complexity being concentrated at the Server. This provides centralized management of the real-time infrastructure. A single server node is assigned to be the Conference Manager and the MRM Top Provider. However, commu
35、nication from clients to the MRM Top Provider is always directed to the Conference Management channel, allowing other Network Elements to also join this channel and to cooperate in delivering the conference. These other Network Elements may shadow the MRM Top Provider, allowing the possibility of on
36、e of them taking on the Top Provider role in the event of a failure condition which disables the current Conference.3This provision also allows the possibility of a distributed management mode in future versions of this protocol, enabling it to more readily scale to support large conference environm
37、ents. This Recommendation requires the services of MCS and GCC. _ 1The use of this Recommendation with H-series Recommendations is outside the scope of this work and is part of a separate harmonization activity. 2Video-streaming excludes solutions based upon Recommendation H.323, which are for furth
38、er study and are outside the current scope. 3This is currently outside the scope of this Recommendation. Recommendation T.137 (02/2000) 2T1607350-99Network Transport Protocols (T.123)NetworkDataUser ApplicationsNode ControllerReal-timeAudioDeviceReal-timeVideoDeviceITU-T Standard ApplicationProtocol
39、 EntitiesAudioStream(s)VideoStream(s)Meeting RoomManagementT.137Non-Standard ApplicationProtocol EntitiesGeneric Conference ControlT.124 (GCC)Multipoint Communication ServiceT.122/T.125 (MCS)Figure 1/T.137 Audiovisual control architecture 2 References The following ITU-T Recommendations and other re
40、ferences 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
41、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 T.120 (1996), Data protocols for multimedia conferencing. ITU-T Recommendation
42、 T.121 (1996), Generic application template. ITU-T Recommendation T.122 (1998), Multipoint communication service Service definition. ITU-T Recommendation T.123 (1996), Network-specific data protocol stacks for multimedia conferencing. ITU-T Recommendation T.124 (1998), Generic Conference Control. Re
43、commendation T.137 (02/2000) 3 ITU-T Recommendation T.125 (1998), Multipoint communication service protocol specification. _ ITU-T Recommendation X.680 (1997) | ISO/IEC 8824-1:1998, Information technology Abstract Syntax Notation One (ASN.1): Specification of basic notation. _ ITU-T Recommendation X
44、.691 (1997) | ISO/IEC 8825-2:1998, Information technology ASN.1 encoding rules Specification of Packed Encoding Rules (PER). 3 Definitions This Recommendation defines the following terms: 3.1 application protocol: Any standard or non-standard protocol specification that makes use of T.120 services.
45、3.2 application protocol entity: The instantiation of an application protocol in a terminal or MCU. 3.3 application protocol session: A group of peer application protocol entities communicating with each other. 3.4 conference framework: A predefined specification for a conference. The framework is c
46、reated out of band but is specified in this Recommendation because it is passed into an active conference and its parameters are available through the conference roster. 3.5 meeting room model: A model of a room to support either a formal or an informal meeting between peers. All role holders are su
47、pported. 3.6 conference room model: A model of a presentation room which, in addition to the meeting room model, supports Observers. 3.7 coffee room model: An informal meeting space which supports ad hoc communication and dynamic creation and destruction of meeting spaces, these meeting spaces are a
48、lso represented by MRM rooms. 3.8 convenor: The entity responsible for creation of the MRM conference. 3.9 MRM conference: A conference in which the MRM protocol is used to manage and control all the media used within the conference. 3.10 MRM top provider: Entity within a node responsible for managi
49、ng an MRM conference. 3.11 MRM conference manager: The name given to the node controller associated with the MRM Top Provider. The conference manager has overall responsibility for running the conference. 3.12 MRM room: A virtual meeting room created within an MRM conference. Effectively, a subset of MRM conference participants formed into a separate and autonomous group of nodes for the purposes of communicating both data and real-time streams within that group. 3.13 MRM group: An association of room participants, allowing them to effecti
