1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU F.732 (I 0/96) SERIES F: NON-TELEPHONE TELECOMMUNICATION SERVICES Audiovisual services Multimedia conference services in the B-ISDN ITU-T Recommendation F.732 (Previously CCITT Recommendation) STD-ITU-T RECMN
2、 F.732-ENGL L77b 48b259L Ob34740 525 ITU-T F-SERIES RECOMMENDATIONS NON-TELEPHONE TELECOMMUNICATION SERVICES TELEGRAPH SERVICE Operating methods for the international public telegram service The gentex network Message switching The international telemessage service The international telex service St
3、atistics and publications on international telegraph services Scheduled and leased communication services Phototelegraph service Mobile services and multidestination satellite services MOBILE SERVICE TELEMATIC SERVICES Public facsimile service Teletex service Videotex service General provisions for
4、telematic services MESSAGE HANDLING SERVICES DIRECTORY SERVICES DOCUMENT COMMUNICATION Document communication Programming communication interfaces DATA TRANSMISSION SERVICES ISDN SERVICES UNIVERSAL PERSONAL TELECOMMUNICATION HUMAN FACTORS F. l-F. 109 F. I-F. 19 F.20-F.29 F.30-F.39 F.40-F.58 F.59-F.8
5、9 F.90-F.99 F. 1 OO-F. 104 F.105-F.109 F.110-F.159 F. 1 1 O-F. 159 F.160-F.399 F.160-F. 199 F.200-F.299 F.300-F.349 F.350-F.399 F.400-F.499 F.500-F. 549 F.550-F.599 F.550-F.579 F.580-F.599 F.600-F.699 F.800-F.849 F.850-F.899 F.900-F.999 For further details, please refer to ITU-T List of Recommendati
6、ons. STD-ITU-T RECMN F.732-ENGL L99b +Ab2591 Ob34941 4b1 = FOREWORD The ITU-T (Telecommunication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommen- dati
7、ons 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
8、 approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). ITU-T Recommendation F.732 was prepared by ITU-T Study Group 1 (1993-1996) and was approved by the WTSC (Geneva, October 9-18, 1996). NOTE In this Rec
9、ommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. O ITU 1997 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical,
10、 including photocopying and microfilm, without permission in writing from the ITU. Recommendation F.732 (10196) i STD-ITU-T RECMN F-732-ENGL L99b D 48b259L Ob34742 3TB D CONTENTS 1 Scope 2 Definition 3 Terminology . 4 Description . 4.1 General description . 4.2 Functional model 4.3 Configuration 4.4
11、 Roles of the participants 4.5 Terminal aspects . 4.6 Applications 4.7 Supplementary services 5 Static aspects 5.1 Service level 5.2 Communication task level . 5.3 Media component level . 6 Dynamic aspects . 6.1 Activation phase 6.2 Communication phase . 6.3 Termination phase . 6.4 Call termination
12、7 Service profiles . 7.1 7.2 Different types of multimedia conference services . List of service profiles 8 Interworkinglintercommunication 8.1 8.2 Access type 7 8.3 Hybrid MCU . 8.4 Interworking with LANs 8.5 Intercommunication between services Attribute table and values . 9.1 9.2 9.3 Access attrib
13、utes . . Interworking between narrow-band and broadband terminals 9 Information transfer high layer attributes . Information transfer low layer attributes Annex A - References . Page 1 1 1 1 1 1 3 3 3 3 3 3 4 4 4 4 4 5 5 5 5 5 7 7 12 15 15 18 18 18 19 19 20 11 Recommendation F.732 (10/96) - STD*ITU-
14、T RECMN FJ32-ENGL L77b W 48b259L Ob34743 234 D SUMMARY This Recommendation encompasses a broad range of related services, including the videoconference service, and also the audiographic conference service, the videophone conference service and CDH (Collaborative Document Handling). It is part of a
15、general framework for Recommendations on multimedia services. This Recommendation refers to Recommendation F.702 (Multimedia conference services) and contains only those parts that require complements or choices between options in order to apply it specifically to B-ISDN and to take full advantage o
16、f its enhanced capabilities. Because in the coming years the broadband conference rooms will have to interwork with the existing narrow-band systems, a large part of this Recommendation is devoted to the various possible configurations for interworking (see clause 8). Thus, when B-ISDN is interconne
17、cted with 64 kbit/s-based ISDN, it will also have to provide the services which are currently provided by this network, and insure interworking with existing narrow-band terminals. . Recommendation F.732 (10/96) 111 STD-ITU-T RECMN F-732-ENGL 177b 48b257L Ob34944 170 D 8-TE Recommendation F.732 6-IS
18、DN S, = T, - MULTIMEDIA CONFERENCE SERVICES IN THE B-ISDN (Geneva, 1996) 1 Scope This Recommendation describes the multimedia conference services supported by a B-ISDN. It relies on Recommendation F.702 for the main body of the description, and only gives the specific complements relevant to the B-I
19、SDN that derive from its capabilities and its limitations. Thus, when reading this Recommendation, it is necessary to refer back to Recommendation F.702. The numbers of the clauses are those of F.702, and thus they do not form a continuous sequence because only a few clauses need a specific compleme
20、nt for the B-ISDN. In addition, there is a new clause 9 on the attributes for the various profiles. Because interworking with the N-ISDN is a major requirement and will probably be a very frequent way of setting up conferences in the next few years, this is described in great detail in clause 8. 2 D
21、efinition See Recommendation F.702. 3 Terminology See Recommendation F.702. 4 Description 4.1 General description See Recommendation F.702. 4.2 Functional model See Recommendation F.702. 4.3 Configuration 4.3.1 The following figures describe the possible basic scenarios corresponding to a multimedia
22、 conference offered at the network access. Configuration at the network access 4.3.1.1 Access type 1 I TO1 05600-96/d01 Figure VF.732 - Configuration Recommendation F.732 (10/96) 1 STD-ITU-T RECMN F.732-ENGL L77b 9 48b257L Ob34945 O07 BIH ch AAL1 ATM PHY Q.2931 Q.2130 - 6-ISUP Q.2140 k 0.2110 M T010
23、5740-Wdl5 Figure 15lF.732 - C-Plane 8.1.2.4 Access type 5 This is another access for a narrow-band terminal to the N-ISDN. Figure 16F.732 - Configuration Recommendation F.732 (10/96) 11 TO1057W-Wdl7 S N-TE IWF 1 Figure 17m.732 - U-Plane 6-ISDN TB 6-NT2 SB - Q.931 Q.931 Q.921 Q.921 D ch PHY - BIH ch
24、B/H ch PHY PH N-ICUP 1 T010577DWdl - ,:MI FB-1 AAL1 ATM PHY PHY Figure 18m.732 - C-plane 8.1.2.5 Access type 6 This is still another access for a narrow-band terminal to the B-ISDN. TO1 05780-961d19 Figure 19m.732 - Configuration Figure 20m.732 - U-Plane 12 Recommendation F.732 (10/96) STD-ITU-T REC
25、MN F-732-ENGL L97b D 48b2592 Ob3495b 792 D N-TE B-ISUP (2.2140 Q.211 O TO1 058W-Wd21 64 kbiffs-based ISDN Figure 2UF.732 - C-Plane - (2.931 Q.921 Dch PHY - 8.2 Access type 7 N-ISUP Q.931 Q.921 pl D ch PHY MTPI . This is an access for a narrow-band terminal to the N-ISDN. Figure 22F.732 - Configurati
26、on TO1 05820-Wd23 Figure 23F.732 - U-Plane Figure 24F.732 - C-Plane Recommendation F.732 (10/96) 13 STD-ITU-T RECMN F.732-ENGL L99b m qAb257L Db34957 27 = 8-ISDN 8.2.1 Scenarios for interworking between B-ISDN and N-ISDN IWF 6 64 kbitls-based ISDN - B/H ch Figure 25F.732 - Configuration B/H ch ATM e
27、 PHY e. ATM PHY PHY PHY TO1 05850-Wd26 Figure 26/F.732 - U-Plane E-ISUP (2.2140 (2.21 1 O N-ISUP MTP3 - Q.2140 e Q.2140 Q.2110 e Q.211 O AAL5 AAL5 MTP2 e MTPZ - ATM ATM PHY PHY MTPI Q.921 TO1 05870-96/d28 Figure 28R.732 - C-plane if B-TE f) B-ISDN f) N-ISDN f) N-TE 8.2.1.1 Point-to-point scenarios A
28、ny end-to-end point-to-point scenario is described by connecting two among all the relevant above figures. 14 Recommendation F.732 (1 0/96) STD-ITU-T RECMN F-732-ENGL L97b H YBb259L Ob34758 7b5 H 8.2.1.2 Multipoint scenarios 8.2.1.2.1 General multipoint considerations There are three kinds of scenar
29、ios which may possibly support a multipoint multimedia conference: 1) Every terminal establishes an end-to-end (unidirectional) connection to each of the other terminals. In this case, the intenvorking is covered by the paragraphs dealing with the point-to-point intenvorking. TO1 05880-Wd29 + TWO re
30、verse ATM connections 4-) One HIB circuit (bidirectional) Mapping entity of two reverse ATM connections onto a bidirectional B or vice versa NOTE - IWF 1 corresponds to TA. Figure 29F.732 - Example of a multipoint scenario using point-to-point connections It should be noted that the B/H-channels are
31、 always bidirectional and the ATM connections are unidirectional. Thus, an interworking constraint is to map one onto the other and vice versa and to determine the associated protocols which are for further study. Every terminal establishes an end-to-end point-to-multipoint (unidirectional) connecti
32、on to all other terminals. 2) It should be noted that an N-TE is not able to establish a point-to-multipoint connection and if there are N terminals, each terminal should have N - 1 decoders and one coder. In the case of the N-TE it does not seem a viable solution. Consequently, such scenarios inclu
33、ding an N-TE are not considered realistic. The way for establishing a multipoint connection in the B-ISDN from an endpoint in the N-ISDN is not defined. Thus, the multipoint aspects of the connection have to be treated in the B-ISDN and the MCU has to be directly connected to the B-ISDN. For the sam
34、e reason as in the first case, this scenario is for further study. 3) Every terminal establishes a couple of end-to-end point-to-point opposite (unidirectional) connections between itself and an MCU. Recommendation F.732 (10/96) 15 _ T, Two opposite ATM connections 4- TO1 05890-96/630 4-b One HIB ci
35、rcuit (bidirectional) Mapping entity of two opposite ATM connections onto a bidirectional B or vice versa 0 Multipoint functions NOTE - IWF is IWF 6. Figure 30E.732 - Example of a multipoint scenario using point-to-point connections For the time being, the initial scenario should be based on an MCU
36、whose accesses are narrow-band. In a second phase, all MCU accesses should be broadband. Offering narrow-band and broadband access in the same MCU needs further considerations. 8.2.1.2.2 MCU connected to the N-ISDN 8.2.1.2.3 MCU connected to the B-ISDN 8.3 Hybrid MCU The hybrid MCU has access to bot
37、h the B-ISDN and N-ISDN, thus bridging the two networks for setting up a multimedia conference with terminals connected to each network. 8.4 Intenvorking with LANs The same types of configurations and scenarios apply to interworking with LANs. If a terminal connected to an LAN supports one or more N
38、-ISDN compatible modes (possibly through a terminal adapter), then it can be connected to an N-ISDN compatible terminal on the B-ISDN network; the gateway between the LAN and the B-ISDN ensures compatibility and continuity of the channels used on both networks. For instance, for terminals with video
39、 capability, conformance of a B-ISDN terminai with Recommendation H.321 ensures compatibility with LAN terminals conforming to Recommendation H.322 (for a LAN with guaranteed bandwidth) or to Recommendation H.323 (for an LAN without guaranteed bandwidth). 16 Recommendation F.732 (1 0196) STD-ITU-T R
40、ECMN F.732-ENGL 177b = 4Bb2.571 Ob3Li7bU 313 ETE TB B-ISDN i 1 3 I. c J TO1 05900-Wd31 + TWO opposite point-to-point connections _, NOTE - IWF 1 corresponds to TA. Figure 31m.732 - Example of multipoint scenario using point-to-point connections B-ISDN N-ISDN 1 T0105910-Wd32 NOTE - IWF 1 corresponds
41、to TA and IWF is IWF 6. Figure 32m.732 - Example of a scenario including a narrow-band MCU Recommendation F.732 (10/96) 17 STD-ITU-T RECMN F.732-ENGL L97b YBb257L Ob347bl 25T U TOI 05920-%/d33 NOTE - IWF 1 corresponds to TA and IWF is IWF 6. Figure 33M.732 - Scenario including a broadband MCU . . T0
42、1059%/634 NOTE - IWF 1 corresponds to TA and IWF is IWF 6. Figure 34fF.732 - Scenario including a hybrid MCU 1s Recommendation F.732 (10/96) 8.5 Intercommunication between services Service type Connection mode All terminals have the media component audio. The basic common audio mode is G.722. Howeve
43、r, some videophone terminals (and possibly some CDH terminals) may not have that capability; in that case G.711 is used, or alternately G.728 if all terminals in the conference have that capability. May correspond to each of the different service profiles (see 7.2) Connection oriented For the media
44、component video, all terminals which support it use H.262 coding, or H.261 for interworking with narrow-band systems. They will always be able to communicate with this coding algorithm, by aligning the bit rate of the video subchannel on the lowest bit rate. If the resulting quality is not sufficien
45、t, then a higher bit rate may be chosen, with some terminals relegated to secondary status and participating with sound (and possibly data) only. Media Component(s) MC(s) Establishment of the service For the other media components, all terminals using them have a common data subchannel with the T. 1
46、20 protocol. The bit rate of the subchannel will be aligned on the terminal with the lowest bit rate capability. However, this does not imply that all terminals will have a common media component. For instance, a group of participants may be able to exchange facsimile while another group (overlappin
47、g or not) may exchange still pictures. MC 1: audio MC 2: video MC 3: synchronous signalling MC 4: data Applicability of MC to service profile is specified in 7.2 Subscription Use on: either demand or reserved 9 Attribute table and values Configuration of the service Supplementary services provided 9
48、.1 Information transfer high layer attributes Point-to-point Multipoint For further study Table 1m.732 - Information transfer high layer attributes for the broadband conference services Quality of service Interworking capabilities 1 2 3 4 5 6 7 8 9 10 11 11.1 11.2 For further study With narrow-band
49、videoconference and narrow-band videotelephony Name of the service I Broadbind conference ATM Adaptation layer MC 1: AAL 1 MC 2: AAL 1 MC 3: AAL 1 MC4:AALlorAALS Information access protocols - Layer 2 above AAL H.222.0, H.222.1 Operational and commercial aspects I Outside of the scope Recommendation F.732 (10/96) 19 STDmITU-T RECMN F.732-ENGL 177b = 48b2572 Ob347b3 O22 W 1 i .3 11.4 Table UF.732 - Information transfer high layer attributes for the broadband conference services (concluded) Information access protocols H.245 - Layer 3 abov
