1、CCITT RECMN*I.23L. i10 92 m 48b2591 057q7Y3 116 m INTERNATIONAL TELECOMMUNICATION UN ION CCITT THE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE INTEGRATED SERVICES DIGITAL NETWORK (ISDN) GENERAL STRUCTURE AND SERVICE CAPABILITIES 1.231 .I O (08/92) CIRCUIT-MODE MULTIPLE-RATE UNRESTRI
2、CTED 8 kHz STRUCTURED BEARER SERVICE CATEGORY Recommendation 1.231 .I O INTERNATIONAL TELECOMMUNICATION UNION CCITT THE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE INTEGRATED SERVICES DIGITAL NETWORK (ISDN) GENERAL STRUCTURE AND SERVICE CAPABILITIES 1.231 .I O (08/92) CI RC U IT-M O
3、 D E M U LTI P LE-R ATE UNRESTRICTED 8 kHz STRUCTURED BEARER SERVICE CATEGORY Recommendation 1.231 .1 O Geneva, 1992 CCITT RECMN*I-23L- LO 92 m 4862573 057V7V5 T99 m FOREWORD The CCT (the Intemationai Telegraph and Telephone Consultative Committee) is a permanent organ of the Intemationai Telecommun
4、ication Union 0. CU“ is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The Plenary Assembly of CC which meets every four years, establishes the topics fa study and approves R
5、ecommendations prepared by its Study Groups. The approval of Recommendations by the members of CCiIT between Plenary Assemblies is covered by the procedure laid down in CCI“ Resolution Nq. 2 (Metborne, 1988). Recommendation 1.231.10 was prepared by Study Group I and was approvkd under the Resolution
6、 No. 2 procedure on the 4th of August 1992. 1 m NOTE In this Recommendation, indicate both a telecommunication Administration and a recognized private operating .*. -. . - *-. o ITU 19% :-L; rl,-*-a AU rights reserved. No part of this publication may be repmdmd or utiiized in any fm 6r by any mea or
7、 mechanical, including phomopying and microfilm, without permission in writing from the ITU. CCITT RECMN*I*231- LO 92 m 4862591 0574746 925 m Recommendation 1.231.10 I I CIRCUIT-MODE MULTIPLERATE UNRESTRICTED 8 IHZ STRUCTURED BEARER SERVICE CATEGORY Maximum number of information channels I available
8、 at user II (I 992) m, where m is not greater than the number of information channels on the interface 1 Definition of the service Assignment of time-slots (see Note) The multiple-rate circuit-mode bearer service for an ISDN interface ailows users to request from the ISDN on a demand basis the estab
9、lishment and release of circuit-mode connections supporting unresicted information transfer rates at integer multiples of 64 kbith up to the maximum rate of the interface. contiguous Non-contiguous The multiple-rate circuit-mode bearer service in a sense extends the circuit-mode bearer service based
10、 on 64 kbit/s by supporting higher information transfer rates. 2 Description 2.1 General description This circuit-mode bearer service category allows: - two users e.g. terminals, private automatic branch exchanges (PABXs) in a point-to-point configuration to communicate via the integrated services d
11、igital network (ISDN) using digitai signals over multiple 64 kbit/s channels, in both directions continuously and simultaneously for the duration of the call; three or more users in a multipoint configuration (refer respectively to Recommendations 1.254.2 and 1.254.1 for the supplementary service de
12、scription on Three-Party Service and Conference Calling). - 2.2 Specific terminology - Retention timer: This timer specifies the amount of time that the network retains the call information of the original call upon encountering busy or being released. It is a network provider option. The value for
13、this timer is greater than 15 s. Contiguous rime slot assignment: The he slots for the cail are adjacent. Non-contiguous time slot assignment: The time slots are not necessarily adjacent. - - 3 Procedures 3.1 Provisiodwithdrawa2 Provision of this service will be by pre-arrangement with the service p
14、rovider. This service can be offered with several options. Examples are: I Subscriber option I Value I Maximum number of total calls present at information channels on the interface 1 Note -This subscription option is not necessary for basic access. Recommendation 1.231.10 (OW92) 1 CCITT RECMN*I*23L
15、 LO 92 486259L 0574747 ClbL Withdrawai of the service is made by the service provider upon request by the subscriber or for seMce provider reasons. 3.2 Normal procedures 3.2.1 Originating the service (call Set-up) The call is originated by the user requesting this service. With the request, the ori
16、ginating user supplies the called party number identifying the destination, the information transfer rate need an indication when the called user has been informed of the call and an indication when the connection has been established. The called user will receive an indication of the arrival of a c
17、all for this bearer semi, including the information transfer rate, and will inform thenetwork of the acceptance or rejection of the cail. The called user may also provide other information for use by the network in supplementary services provided to other users (e.g. Connected-Line Identity). The re
18、lationship of a .connected user with the called user requires further study. Once the connection is established between the calling and called users, the ail0cat.d time slot(s)/channel(s) idare available for the transmission in both directions continuously and simultaneously at the information trans
19、fer rate specified at call Set-up until the cail is tem. 3.2.3 Terminating the call A call may be terminated by either or both users indicating tis ko the network. If one user or both usefs terminate the call, the network will send an apgroPriate mication to the other user. 3.3 Exceptwnal proceures
20、The exceptional procedures hle the foliowing conditions: a) Failure situations due to user error i) A user inputting a network-identifiable, improper service request wiJ4 gi 2) information transfer rate: 128, 192, . . ., 1920 kbits; 3) 4) 5) information transfer capability: unrestricted digital info
21、rmation; structure: 8 IrHz with time slot sequence integrity; establishment of communication: demand (other methods are for further study); 6) symmetry: bidirectional symmetric (other types of symmetry are for further study); 7) communication configuration: point-to-pomt (other configurations are fo
22、r further study). 7.2 Access attributes 1) access channel and rate: multiple B-cbannels (other Cbannels 8te for further study); 2) access protocol: I-Series for D-channel. 7.3 General uttributes (for further study) 1) supplementary services provided, 2) QualityofService; 3) interworking possibilities; 4) operational and commercial. 8 Provision of individual multirate circuit-mode bearer semices For further study. 9 Dynamic description The dynamic description of this service on a demand basis is given in Recommendat macro definition: incoming d Recommendation 1.231.10 (08/92) 5
