1、INTERNATIONAL TELECOMMUNICATION UNION ITU=T TEL ECO M M U N I CATI ON STANDARDIZATION SECTOR OF ITU 1.375.1 (06/98) SERIES I: INTEGRATED SERVICES DIGITAL NETWORK Overall network aspects and functions - General network requirements and functions Network capabilities to support multimedia services: ge
2、neral aspects ITU-T Recommendation 1.375.1 (Previously CCIlT Recommendation) ITU-T I-SERIES RECOMMENDATIONS INTEGRATED SERVICES DIGITAL NETWORK GENERAL STRUCTURE Terminology Description of ISDNs General modelling methods Telecommunication network and service attributes General description of asynchr
3、onous transfer mode Scope General aspects of services in ISDN Common aspects of services in the ISDN Bearer services supported by an ISDN Teleservices supported by an ISDN Supplementary services in ISDN SERVICE CAPABILITIES OVERALL NETWORK ASPECTS AND FUNCTIONS Network functional principles Referenc
4、e models Numbering, addressing and routing Connection types Performance objectives I. 1 10-1.119 I. 120-1.129 I. 130-1.139 I. 140-1.149 I. 1504.199 1.200-1.209 1.210-1.219 1.220-1.229 1.230-1.239 1.240-1.249 1.250-1.299 1.3 161.3 19 1.320-1.329 1.330-1.339 1.340-1.349 1.350-1.359 Protocol laver reau
5、irements 1.360-1.369 Generalnetwork requirements and fnnctions 1.370-1.399 ISDN USER-NETWORK INTERFACES Application of I-series Recommendations to ISDN user-network interfaces Layer 1 Recommendations Layer 2 Recommendations Layer 3 Recommendations Multiplexing, rate adaption and support of existing
6、interfaces Aspects of ISDN affecting terminal requirements INTERNETWORK INTERFACES MAINTENANCE PRINCIPLES B-ISDN EQUIPMENT ASPECTS ATM equipment Transport functions Management of ATM equipment 1.420-1.429 1.430-1.439 I .440-I .449 1.450-1.459 1.460-1.469 1.470-1.499 1.500-1.599 1.600-1.699 1.730-1.7
7、39 1.740-1.749 1.750-1.799 For further details, please refer to ITU-T List of Recommendations. ITU-T RECOMMENDATION 1.3751 NETWORK CAPABILITIES TO SUPPORT MULTIMEDIA SERVICES: GENERAL ASPECTS Summary This Recommendation specifies the general aspects of network capabilities for the support of multime
8、dia services, including audiovisual services. Network capabilities to support multimedia services and applications are described by means of reference configurations and corresponding network architectures. Functional blocks in the architecture are identified and the physical and logical relationshi
9、ps among these blocks are described. Although assumptions must necessarily be made regarding the functionality of Customer Premises Equipment (CPE), specific requirements for CPE are outside the scope of this Recommendation. Source ITU-T Recommendation 1.37.5.1 was prepared by ITU-T Study Group 13 (
10、1997-2000) and was approved under the WTSC Resolution No. 1 procedure on the Ist of June 1998. Keywords Functional groups, Multimedia services, Network capabilities, Reference configuration. Recommendation 1.375.1 (06198) 1 FOREWORD ITU (International Telecommunication Union) is the United Nations S
11、pecialized Agency in the field of telecommuni- cations. The ITU Telecommunication Standardization Sector (IT-T) is a permanent organ of the IT. The IT-T is responsible for studying technical, operating and ariff questions and issuing Recommendations on them with a view to standardizing telecommunica
12、tions 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
13、-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 standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression “Administration“ is used for concis
14、eness 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
15、no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by IT 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 prope
16、rty, 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. O ITU 1998 All rights reserved. No part of this publication m
17、ay be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the . 11 Recommendation 1.375.1 (06/98) CONTENTS 1 Scope 2 General network requirements for multimedia service classes . . . 2.1 Multimedia con
18、ference services class . 2.2 Multimedia conversation services class 2.3 Multimedia distribution services class . . 2.4 Multimedia retrieval services class . 2.5 Multimedia collection services class . 2.6 Multimedia message services class . Recommendation 1.375.1 (06/98) - - Page 1 1 3 5 6 8 9 11 . 1
19、11 STD-ITU-T RECMN 1-375-1-ENGL 1998 m 4862591 Ob49509 9T7 m Enduser - functions I Recommendation 1.375.1 _ - Access Transport Access - End user functions functions functions functions NETWORK CAPABILITIES TO SUPPORT MULTIMEDIA SERVICES: GENERAL ASPECTS (Geneva, 1998) Content server functions 1 Scop
20、e This Recommendation specifies the general aspects of network capabilities for the support of multimedia services, including audiovisual services. Network capabilities to support multimedia services and applications are described by means of reference configurations and corresponding network archit
21、ectures. Functional blocks in the architecture are identified and the physical and logical relationships among these blocks are described. Although assumptions must necessarily be made regarding the functionality of Customer Premises Equipment (CPE), specific requirements for CPE are outside the sco
22、pe of this Recommendation. Relationships between service provider(s), content provider(s) and network provider(s) are outside the scope of this Recmmendation. Access End user functions - functions - 2 According to Recommendation F.700 (Framework for Multimedia Services), the following multimedia ser
23、vice classes are considered: conference services; conversation services; distribution services; retrieval services; collection services; message services. Figure 1 shows the reference configuration which is applicable to all multimedia service classes. General network requirements for multimedia ser
24、vice classes Figure 1A.375.1- Reference configuration applicable to ali classes of multimedia services * This Recommendation replaces Recommendation 1.374: Network Capabilities to support multimedia services. Recommendation 1.375.1 (06/98) STDOITU-T RECMN 1-375.3-ENGL 1998 48b2591 Ob49530 bL9 The fu
25、nctional groups of this reference configuration contain functions which are required to support all multimedia service classes, as follows: NOTE 1 - The following lists may not necessarily be exhaustive. 0 End userfunctions - Application control functions: These functions are needed to control the a
26、pplication by the exchange of messages between the end user and the content server via the service provider. They differ fiom service to service and will therefore not be described on this level. - Network control functions: These functions are needed to control the network by the exchange of messag
27、es between the end user and the service provider. They also differ from service to service and will therefore not be described on this level. - Information handling functions, e.g.: Access control functions: These functions are related to security aspects, e.g. needed to ensure authentication and au
28、thorization. Information conversion. Information encoding and decoding. Information encryption and decryption. Data stream termination functions, e.g.: ATM termination (if applicable). Error correction handling. - MPEG-2 transport stream termination (if applicable). Access functions - - Transport in
29、terface termination function. - Access bearer handling. - Bearer channel concentration. - - - Multiplexing/demultiplexing. - End user interface termination function. Signalling and packet information multiplexing/demultiplexing. Circuit emulation for the ATM transport. Cross-connect function includi
30、ng grooming and configuration. Transportfunctions - - - - Network control functions. Service provider selection functions Transport of bearer information (user information). Transport of protocol information for signalling. Transport of protocol information for operation and maintenance. - - Selecti
31、on of service provider. - Termination of network control functions. Navigation functions related to the service provider, including directory functions. Service provider functions - Distribution (duplication) functions. - Collection (merge) functions. - Content selection functions. - Broker function
32、s. 2 Recommendation 1.375.1 (06198) - STD-ITU-T RECMN 1.375.1-ENGL 1998 4862593 Ob495LL 555 9 Enduser - Access - Transport Access functions functions functions functions - Billing functions. - Navigation functions related to the content. Content server functions - Application preparation and storage
33、. - - Information generation. Termination of application control functions. NOTE 2 - The Servers from which content is loaded on to the Content Server Functions as well as the network through which this process is carried out are outside the scope of this Recommendation. End user functions These fnc
34、tional groups are separated by the indicated reference points. The naming, definition and description of the reference points is for further study. The following subclauses describe reference configurations which are specific to a particular service class. u- 2.1 Multimedia conference services class
35、 - Multimedia conference services are characterized by multipoint communication and bidirectional information exchange. Multipoint service can be provided by a transport function or service function (e.g. MCU). The reference configuration for the multimedia conference services class is shown in Figu
36、re 2. It presents the functions of multimedia conference services to be supported by network capabilities. Access functions - End user functions Figure 24.3751 - Reference configuration for multimedia conference services class The functional groups contain the following functions to be supported: NO
37、TE - The following lists may not necessarily be exhaustive. End userfunctions - Application control functions: These functions are needed to control the application by the exchange of messages between the end user and the service provider. They differ from conference service to conference service an
38、d will therefore not be described on this level. Recommendation 1.375.1 (06/98) 3 - STD-ITU-T RECMN 1.375.1-ENGL 1998 48b2591 Ob49512 491 m - Network control functions: These functions are needed to control the network by the exchange of messages between the end user and the service provider. They a
39、lso differ fiom conference service to conference service and will therefore not be described on this level. - information handling functions, eg: Access control functions: These functions are related to security aspects, e.g. needed to ensure authentication and authorization. Information encoding an
40、d decoding. Information encryption and decryption. Data stream termination functions, e.g.: ATM termination (if applicable). Information conversion. Error correction handling. - MPEG-2 transport stream termination (if applicable). Accessfunctions - - Transport interface termination function. - Acces
41、s bearer handling. - Bearer channel concentration. - - - Multiplexingdemultiplexing. - End user interface termination function. Signalling and packet information multiplexing/demultiplexing. Circuit emulation for the ATM transport. Cross-connect function including grooming and configuration. Transpo
42、rtfunctions - - - - Network control functions. Service provider selection functions Multipoint transport of bearer information (user information). Multipoint transport of protocol information for signalling. Multipoint transport of protocol information for operation and maintenance. - - Selection of
43、 service provider. - Termination of network control functions. Navigation functions related to the service provider, including Directory functions. Service provider functions - Distribution (duplication) functions. - Collection (merge) functions. - Broker functions. - Billing functions. - Reservatio
44、n function. These functional groups are separated by reference points. The definition and description of the reference points is for further study. 4 Recommendation 1.375.1 (06198) STD-ITU-T RECMN 1.375.3-ENGL 1978 M 48b2591 0647533 328 Enduser functions 2.2 Multimedia conversation services class Mu
45、ltimedia conversation services are characterized by point-to-point communication and bidirectional information exchange. The reference configuration for the multimedia conversation services class is shown in Figure 3. It presents the functions of multimedia conversation services to be supported by n
46、etwork capabilities. - Access _ Transport - Access - Enduser functions functions functions functions Service provider selection functions Service provider functions Figure 3I.375.1- Reference configuration for multimedia conversation services class The functional groups contain the following functio
47、ns to be supported: NOTE - The following lists may not necessarily be exhaustive. End user functions - Application control functions: These functions are needed to control the application by the exchange of messages between the end user and the service provider. They differ fiom conversation service
48、 to conversation service and will therefore not be described on this level. - Network control functions: These functions are needed to control the network by the exchange of messages between the end user and the service provider. They also differ from conversation service to conversation service and
49、 will therefore not be described on this level. - Information handling functions, e.g.: Access control functions: These functions are related to security aspects, e.g. needed to ensure authentication and authorization. Information conversion. Information encoding and decoding. Information encryption and decryption. Data stream termination functions, e.g.: ATM termination (if applicable). 0 Error correction handling. - WEG-2 transport stream termination (if applicable). Accessjnctions - End user interface terminat
