CEPT T GSI 01-02 E-1985 ISDN Definition《ISDN定义》.pdf

1、CEPT T/GSI*OL-02 E 85 H 232b4L4 0005293 T H T/GSI O1 -02 E Page 1 Recommendation T/GSI O1 -02 (Nice 1985) concerning ISDN definition Recommendation proposed by the Special Group Intergration (GSI) Text of the Recommendation ndopted by the “Telecommimicatioris” Commission: “The European Conference of

2、 Posts and Telecommunications Administrations, Considering - the common CEPT approach to the ISDN and general CEPT assumptions and policies for the evolution towards ISDN; - the I. Series Recommendations of the CCITT, as well as other CCITT Recommendations on ISDN, to which CEPT Administrations have

3、 contributed most significantly; - the need for CEPT Administrations to have more precise answers to their specific European requirements, Le. to select and further dene material from CCITT Recommendations; - the need for CEPT Administrations to have as a base a comprehensive set of Recommendations,

4、 in order to promote and strengthen European harmonisation. Recommends - to the members of the CEPT, that they evolve their telecommunication networks towards ISDN according to the e guidelines and specifications given in the attached text.” Within the general context of a common trend in European t

5、elecommunications today towards the use of digital techniques and service integration, national conditions and commercial policies affect the emphasis given on either an early provision of full digital connectivity or of customer-perceived service integration. Therefore, a common concept of Integrat

6、ed services digital network (ISDN) is based on the following principles. 1. The main feature of the ISDN concept is the support of a wide range of voice and non-voice applications in the same network. A key element of service integration for an ISDN is the provision of a range of service using a lim

7、ited set of connection types and multipurpose user-network interface arrangements (see volumes 3 to 6 of the CEPT set of Recommendations). 2. ISDNs support a variety of applications including both switched and non-switched connections. Switched connections in an ISDN include both circuit-switched an

8、d packet-switched connections and their concatenations. 3. New services introduced into an ISDN are designed to be compatible with 64 kbit/s switched digital connections. 4. An ISDN will contain intelligence for the purpose of providing service features, maintenance and network management functions.

9、 This intelligence may not be sufficient for some new services and may have to be supplemented by either additional intelligence within the network, or possibly compatible intelligence in the user terminals. 5. A layered protocol structure should be used for the specification of the access to an ISD

10、N. Access from a user to ISDN resources may be very depending upon the status of implementation of national ISDNs during a transitional period. 6. It is recognized that ISDNs may be implemented in a variety of configurations according to specific national situations, at least at early stages. Edition of Septembre 15, 1985