1、CCITT RECMN*I.255. I 92 W 4862591 0574751 292 W INTERNATIONAL TELECOMMU N CATION UN ION CCITT THE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE INTEGRATED SERVICES DIGITAL NETWORK (ISDN) GENERAL STRUCTURE AND SERVICE CAPABILITIES 1.255.1 (08/92) CLOSED USER GROUP Recommendation 1.255.
2、1 3 CCITT RECMN*I.255- I 92 486259L 0574752 I29 INTERNATIONAL TELECOMMUNICATION UN ION CCITT THE INTERNATIONAL TELEGRAPH AND TELEPHONE CONSULTATIVE COMMITTEE INTEGRATED SERVICES DIGITAL NETWORK (ISDN) GENERAL STRUCTURE AND SERVICE CAPABILITIES 1.255.1 (OW92) CLOSED USER GROUP Recommendation 1.255.1
3、Geneva, 1992 I CCITT RECMN*Im255. II 92 m 48b259II 0574753 Ob5 m, FOREWORD The CCI“ (the International Telegraph and Telephone Consultative Committee) is a permanent organ of the International Telecommunication Union O. CCI“ is responsible for studying technical, operating and tariff questions and i
4、ssuing Recommendations on them with a view to standatb%in spis oo a worldwide basis. The Plenary Assembly of CClT which meets every four years, establishes the topics for study and approves Recammendations prepared by its Study Groups. The approval of Recoiuwbab by the meanbers of CCT between Plenar
5、y Assemblies is covered by the procedure laid down in CXT Rsolution Mo; 2 (Mdboume, 1988). Recommendation 1.255.1 was revised by Study Group and was approved under the Resolution No. 2 procedure on the 4th of August 1992. ,- A list of abbreviations used in thisRecommerbdation can be found in Annex A
6、. . 4, Q ITU 1992 Ali rights reserved. No part of this publication may be reprodud or utilized in any form or by any C or mecbanid, includmg photocopying and microfilm, without permission in writing from the ITU. CCITT RECN“cI.255. II 92 = 4b25L 0574754 TTL m Recommendation 1.255.1 CLOSED USER GROUP
7、 (revised 1992) 1 Definition The Closed User Group supplementary service enables users to form groups, to and from which access is restricted. A specific user may be a member of one or more Closed User Groups. Members of a specific Closed User Group can communicate among themselves but not, in gener
8、al, with users outsi - Closed User Group with incoming access (c + i); - - A user may subscribe to one of two additional access restrictions within each particular CUG - - Note - This information is held by the provider of this service. All of these cases are illustrated in Figure 1A.255. Closed Use
9、r Group with outgoing access (c + o); Closed User Group with incoming and outgoing access (c + i + o). incoming calls barred within a CUG (ICB); outgoing cails barred within a CUG (OCB). Recommendation 1.255.1 (OWZ) 1 CCITT RECMN*I-255- II 92 qBb259L 0574755 938 i Case 1 1- open- case 4 ICB OCB U CU
10、Gj case7 cti ClJG I c-. x- ttt co 20 201 ICB OCB CUGj I case 10 case 2 CUGj 0 Case 5 I 4 4 cli Cti c$i ICB OCB CUGj I Case 8 1 6- c+o cto c+o ICB OCB ICUCi case 11 OCB c+o c+o c+o ICB OCB c CU0 c+o CUGwithou$oingaccess c + i CU0 with incoming access ICB Iming calle barred witMn CUG OCB OutgoingWls b
11、arred within CUG c case.3 :. . case6 2 Recommendation .ZS5.1 (Om) CCITT RECMN*I*255* L 92 D 4862591 057475b 874 D 2.1.1.1 CVG only capabilities I The user may make calls to, and receive calls from members of those CUGs of which the user is a member (see case 1 in Figure 1A.255.1). An exception to th
12、is is when either incoming calls barred within the CUG or outgoing ds barred within the CUG applies. a) Incoming calk burred within the CUG: ?his access restriction means that a CUG user is prohibited from receiving calls hm users subscribed to the same CUG. This access restriction is given per CUG-
13、user and CUG (see case 2 in Figure 1fi.255.1). Outgohg calls barred within the CVG: This access restricion means that a CUG-user is prohibited from making calls to users subscribed to the same CUG. This access restriction is given per CUG user and CUG (see case 3 in Figure lfi.255.1). b) The network
14、 shall provide a preferential CUG option whereby one of the users CUGs (or the only one if a single CUG applies) is used as a preferential CUG. if the user sets up a ca with no CUG facility request, the network assumes that the preferenitial CUG is requested (i.e., preferential CUG is the default).
15、2.1.1.2 CVG with outgoing access The user may make and receive calls in the same way, with the same exception as in 8 2.1.1.1. in addition, this user can make calls to all other non-CUG users, and to those other CUG users who ailow incoming access. incoming calls are only allowed from members of the
16、 users CUG(s) (see cases 4,5, and 6 in Figure lA.255.1). 2.1.1.3 CUG with incoming access The user may make and receive calls in the same way with the same exceptions as in 8 2.1.1.1. in addition, this user may receive calls from any non-CUG user and also from other CUG users who have outgoing acces
17、s. Outgoing calls are only allowed to members of the users CUG(s) (see cases 7,8, and 9 in Figure 1A.255.1). 2.1.1.4 CUG with incoming and outgoing access The outgoing access and incoming access can be offered simultaneousiy to the user by the service provider. 2.1.2 Interaction between the options
18、“Preferential CUG” and “Outgoing Access” Both options imply that no subscriber procedures are needed to invoke either of them when placing a call. When a user subscribes to both options, the service provider does not know which option the user is invoking, if no additional subscriber procedures are
19、used when placing the call. Three ways of operating are recommended 1) the user has to indicate if a call is intended to be an outgoing access call. If no information (CUG request or outgoing ca request) is given, the preferentiai CUG is assumed, the combination of the options is not dowed, i.e. a u
20、ser cannot have both options aliocated at the same time; 2) 3) the caller may make a ca and the network will route the call with the preferential CUG and an outgoing access request The call wili therefore be connected if the ded number is a member of the Preferential CUG or is a member of a differen
21、t CUG and has incoming access, or is a non-CUG user. The choice of operation is a national option. 2.2 Specific terminology Recommendation 1.255.1 (OW2) 3 CCITT RECMNUI.255. 1 92 48b2591 0574757 700 2.3 Qualifications on the applicability to tekcommwiicatwn services L *. None identified. .L . 1, 3.1
22、 ProvisionhuitMrawal The CUG service is provided on a subscription basii. As a network pvidw option, CW caa be offered with severai subscription options. The subscriber options may apply separately to iccs I AUbaSiCthe Ea between the transferring party and the transferred-to-party; between the &g/de
23、d party and the transferred-to-party. Connected Line Identi&ation Presentation No impact, i.e. neither supplementary service affects the operation of the other supplementary service. Connected Line Identification Restriction No impact, i.e. neither Supplementary service affects the operation of the
24、other supplementary service. Calling Line Identijcation Presentation No impact, i.e. neither supplementary service affects the operation of the other supplementary service. Calling Line Identijcatwn Restriction No impact, i.e. neither supplementary service affects the operation of the other suppleme
25、ntary service. Closed User Group Not applicable. Conference Calling “ben the first call is added to the conference, then the conference assumes the CUG of the call. In order to 6.7 6.8 add a subsequent call to the conference, the CUG of that call should be checked against the CUG of the conference.
26、6.9 Direct-Dialling-In Closed User Group membership should not be available on a per Direct-Dialling-In DI) number basis, but instead sbould be on the basis of entire range of ISDN numbers applicable at the access or group of accesses. Recommendation 1255.1 (OW) 7 I CCITT RECMN*I-255- I 92 D 4862591
27、 05747bL 131 D 3 6.10 Call diversion services , z, *, .-*a *, 1 “ , No impact, i.e. neither supplementary service affects the operation of the other supplementary service. Macwus Call Identification No impact, i.e. neither supplementary servi affects the operation of the &er supplementary service. O
28、utgoing Call Barring No impact, i.e. neither supplementary service affects the operation of the other supplementary service. Reverse Charging No impact, i.e. neither supplementary service affects the operation of the other supplementary service. Sub-addressing No impact, i.e. neither supplementary s
29、ervice affects the operation of the other supplementary service. Dynamic description The dynamic description of this service is shown in Figure 2fl.ZS.l. Recommendation 1255.1 (OsJ92) 9 P CCITT RECMNxI.255. L 92 m 4b259L 05747b3 TO4 mi FGRE 2ISS.l (sheet 1 of4) Ched User Group CCITT RECMN*I*255- L 9
30、2 4Bb259L 05747b4 940 o Reject call a o o A in 32.1.2 c Select CUG FIGURE uI.255.1 (sheet 2 of 4) Closed User Group Setup CUG call with OA allowed o3 TO102230-92 II Recommendation 1.255.1 (OW2) FIGURE uI.255.1 (sheet 4 of 4) Cid User Group Recommendation 1255.1 (OWZ) 13 (to Recomnumdation 1255.1) Ai
31、phabethl list of abbreviatiom used in this Recommandation CLIP calling line identification presttitation CUG closed user group CUGA Closed user group with outgohg access IC interlock code ICB (CUG) humhg calls bacred witbm the CUG ISDN Integrated services digital network ISPBX MLPP Multi-level prewleuce and preemption . 1. Integrated services private branch exchange 1. ,?.$* -L MSN Multiple subscrib& number ,- - tu“ OA outgoing access % -r 4 OCB (CUG) Outgohg calls barred witbin the CUG PCUG CUG preferentinil.
