1、O CEPT T/SF*bS*E 93 m 2326434 0012678 947 m Recommendation T/SF 69 (Madrid 1991) INTER IATIONAL SWITCHED 2 Mbit/s BEARER SERVICE T/SF 69 E Page 1 C) Recommendation proposed by the Working Group T/WG 7 “Services and Facilities” (SF) Text of the Recommendation adopted by the “Commercial Action Committ
2、ee (CAC) : “The European Conference of Postal and Telecommunications Administrations, considering - that several 2 Mbit/s networks exist and that others are being planned, - that some networks have been connected internationally, - that EBIT and other trials and national services have made such a se
3、rvice technically feasible and have indicated - that there is an increasing demand for high-speed switched connections, - that the applications could include, e.g.: the market, - high-speed data transmission, including LAN-LAN interconnection - videoconferencing - high quality audio transmission - i
4、mage transmission, - that customers will benefit from the provision of a Co-ordinated harmonized International 2 Mbit/s service, - that Opeators may wish to provide such a service, - that Operators marketing will benefit from a clear and shared concept of such a service, recommends - that an Interna
5、tional switched 2 Mbit/s bearer service be introduced, - that the user interface and technical aspects are as specified in Annex A, - that accounting mechanisms be agreed, - that transparent charging principles be established.” - Note. (#) user bit rate: 1920 kbit/s. Edition of August 5, 1991 CEPT T
6、/SF*b+E 91 m 232bYL4 0032b9 883 m T/SF 69 E Page 3 Annex A I. INTRODUCTION, METHODOLOG Y The description methodology of CCITT 1.130 Recommendation is used in this Annex, although the recommended 2 Mbit/s switched bearer service may not be an ISDN service described at an S or T-reference point (1.210
7、). Seen from the users point of view, it is of no importance whether the service is supported by an ISDN or another dedicated network. II. SER VICE DESCRIPTION: BEARER SER VICE II. 1. II. 1.1. Definition GENERAL SERVICE DEFINITION AND DESCRIPTION This bearer service provides the unrestricted transfe
8、r of 1920 kbit/s user information over a H12 channel. II. 1.2. Description General: The dynamic description for this service in an ISDN environment is specified in Recommenda- tion 1.231.8. A possible evolution of the service offering to support n x 64 kbit/s bearer service is under study. Accesses
9、based on specifications of the I-series primary rate interface are for further study. O II. 1.3. Procedures a) Provision Provision of this service will be by pre-arrangement with the Administration and will be offered by subscription. b) Normal calling Establishment of a call: The establishment of c
10、ommunication is on demand: an on-demand call is dialled by the user and the connection is established almost immediately (a few seconds) by means of user network signalling. When the call is answered, the H12 channel is then available for the transmission of 1920 kbit/s signals in both directions co
11、ntinuously and simultaneously, without alteration by the network. No restriction is placed by the network on the content of the digital signals. Terminating the call: The call may be terminated by either of the users by indicating this to the network. If one user terminates the call, an appropriate
12、indication is sent to the other user. Numbering: Only one subscriber number is associated with the service/interface. For the numbering plan, CCITT Recommendation E. 164 should be applied to ensure possible evolution towards the B-ISDN. Calls may be established by reservation. Failure situations: fa
13、ilure situations due to called user state or network conditions should be indicated to the calling user by the network using appropriate failure indication. c) Booking d) Exceptional procedures II. 1.4. Network capabilities for charging The principles of charging should be harmonised in order to fac
14、ilitate uniformity of charging from the customers point of view. The basis for charging should include: a) installation charge b) a (periodic) rental charge c) usage charges d) on-demand calls are to be paid by the calling party e) booking charges II. 1.5. Interworking requirements Interworking capa
15、bilities with European Videoconferencing Service (EVS) are to be provided. O Edition of August 5, 1991 CEPT T/SF*bS*E 91 M 232bVLV 0012b80 5T5 T/SF 09 E Page 4 II. 1.6. II. 1.7. 11.2. III. 1. 111.1.1. III. 1.2. Quality of service The quality of service should be appropriate to high speed digital com
16、munication as regards transmission. Blocking quality of service is for further study. Operational and commercial aspects A number of national services exist and some have already been interconnected to provide international service. This expansion will continue. In addition, it could be possible to
17、generate new international applications by using field trials. In that case, a small number of common customers could be involved in test applications. A provisional usage charge could be applied during such field trials. STATIC DESCRIPTION Attributes 1. Information transfer mode 2. Information tran
18、sfer rate 3. Information transfer capability 4. Structure 5. Establishment of communication 6. Symmetry 7. Communication configuration 8. Access channel and rate sa). Signalling access protocol 9b). Information access protocol 10. Supplementary services provided 11. Quality of service 12. Interworki
19、ng possibilities 13. Operational and commercial aspects Values, remarks Circuit 1920 kbit/s Unrestricted digital information 8 kHz and time slot sequence integrity Demand. Reserved may be available Bidirectional symmetric Point-to-point. Optionally, point-to-multipoint H12, 1920 kbit/s (time slot O
20、V.11lV.36 Closed user group As specified in II. 1.7. Based on CEPT Recommendation T/CAC 1 E on European Video- conference Service As specified in 11.1.8. (*I At present, these could include X.21 and proprietary protocols, but I-series protocols are anticipated in future. III. SER VICE DESCRIPTION: S
21、UPPLEMENTARY SER VICE GENERAL SERVICE DEFINITION AND DESCRIPTION Definition Closed User Group (CUG) is a supplementary service that enables users to form groups, to and from which access is restricted. A specific user may be a member of only one CUG. Members of a specific CUG can communicate among t
22、hemselves but not, in general, with users outside the group. Specific CUG members can have additional capabilities which allow them to originate calls outside the group, and/or to receive calls from outside the group. Specific CUG members can have additional restrictions that prevent them from origi
23、nating calls to other members of the CUG, or from receiving calls from other members of the CUG. Description Recommendation 1.255 applies. The number of CUGs per access is limited to one. Edition of August 5, 1991 T/SF 69 E Page 5 Basic service Closed user group III. 1.3. Procedures Value - one CUG
24、I Subscription option I Value I Type of inter CUG access (iniout of CUG) Intra-CUG restrictions - none - outgoing access - incoming access - outgoing and incoming access - none - incoming calls barred - outgoing calls barred III. 1.4. Operational and Commercial Aspects The Closed User Groups numbering should be harmonized internationally. CUGs shall be administered in an appropriate way. The administration method is for further study. Edition of August 5, 1991
