ITU-T Q 2951-1995 Stage 3 Description for Number Identification Supplementary Services Using B-ISDN Digital Subscriber Signalling System No 2 (DSS 2) - Basic Call - Clause 1 - Direcrib.pdf

1、ITU-T RECMN*d-2953 95 m 4862593 Ob02878 093 m INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU B-ISDN APPLICATION PROTOCOLS FOR ACCESS SIGNALLING Q.2951 (02/95) STAGE 3 DESCRIPTION FOR NUMBER IDENTIFICATION SUPPLEMENTARY SERVICES USING B-ISDN DIGITAL SUBSCR

2、IBER SIGNALLING SYSTEM NO. 2 (DSS 2) - BASIC CALL Clause 1 - Direct-Dialling-ln (DDI) Clause 2 - Multiple Subscriber Number (MSN) Clause 3 - Calling Line Identification Presentation (CLIP) Clause 4 - Calling Line Identification Restriction (CLIR) Clause 5 - Connected Line Identification Presentation

3、 (COLP) Clause 6 - Connected Line Identification Restriction (COLR) Clause 8 - Sub-addressing (SUB) ITU-T Recommendation Q.2951 (Previously “CCIlT Recommendation”) COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesFOREWORD The ITU-T (Tele

4、communication Standardization Sector) is a permanent organ of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommen- dations on them with a view to standardizing telecommunications on a worldwide basis. T

5、he 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-T is covered by the procedur

6、e laid down in WTSC Resolution No. 1 (Helsinki, March 1-12, 1993). ITU-T Recommendation Q.2951, clauses 1,2,3,4,5,6 and 8 was prepared by ITU-T Study Group 11 (1993-1996) and was approved under the WTSC Resolution No. 1 procedure on the 7th of February 1995. NOTE In this Recommendation, the expressi

7、on “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. O ITU 1995 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying a

8、nd microfilm, without permission in writing from the ITU. COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesCONTENTS 1 Direct-Dialling-In (DDI) Appendix I (to clause 1 of Recommendation 4.2951) - Signalling flows . 2 Multiple Subscriber N

9、umber (MSN) Appendix I (to clause 2 of Recommendation 4.2951) - Signalling flows . 3 Calling Line Identification Presentation (CLIP) Annex A (to clause 3 of Recommendation 4.295 1) - Two-calling party number information elements delivery option . Appendix I (to clause 3 of Recommendation Q.2951) - S

10、ignalling flows . 4 Calling Line Identification Restriction (CLIR) Appendix I (to clause 4 of Recommendation 4.2951) - Signalling flows . Appendix I (to clause 5 of Recommendation 4.2951) - Signalling flows . Appendix I (to clause 6 of Recommendation 4.2951) - Signalling flows . 5 Connected Line Ide

11、ntification Presentation (COLP) . 6 Connected Line Identification Restriction (COLR) . 8 Sub-addressing (SUB) Appendix I (to clause 8 of Recommendation 4.2951) - Signalling flows . Appendix II (to clause 8 of Recommendation 4.2951) - Relationship of address information elements and supplementary ser

12、vices Page 1 5 5 10 10 21 22 23 28 28 41 41 46 46 50 50 1 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECMN*Q.2751 75 m 4862573 Ob02883 b88 m SUMMARY 1 This Recommendation defines the operation of the Digital Subscriber Signal

13、ling System No. 2 (DSS 2) for the support of the following number identification supplementary services: Clause 1 - Direct-Dialling-In (DDI) Clause 2 - Multiple Subscriber Number (MSN) Clause 3 - Calling Line Identification Presentation (CLIP) Clause 4 - Calling Line Identification Restriction (CLIR

14、) Clause 5 - Connected Line Identification Presentation (COLP) Clause 6 - Connected Line Identification Restriction (COLR) Clause 8 - Sub-addressing (SUB) The Recommendation defines the operation for the support of the services at the TB or at the coincident SB and TB reference point of the user to

15、network interface of the Broadband Integrated Services Digital Network (B-ISDN). 2 A brief description of the services is the following: This DDI supplementary enables a user to call directly to another user on a B-ISDN private branch exchange or other private systems, without attendant intervention

16、 based exclusively on the use of the ISDN number. The MSN supplementary service provides the possibility for assigning multiple ISDN numbers to a single public or private access. Calling Line Identification Presentation (CLIP) is a supplementary service offered to the called party which provides th

17、e calling partys ISDN number, possibly with sub-address information, to the called party. Calling Line Identification Restriction (CLIR) is a supplementary service offered to the calling party to restrict presentation of the calling partys ISDN number and sub-address to the called party. Connected L

18、ine Identification Presentation (COLP) is a supplementary service offered to the calling party which provides the connected partys ISDN number, possibly with sub-address information, to the calling party. Connected Line Identification Restriction (COLR) is a supplementary service offered to the call

19、ed party to restrict presentation of the connected partys ISDN number and sub-address to the calling party. The sub-addressing supplementary service allows the called (served) user to expand his addressing capacity beyond the one given by the ISDN number. 11 Recommendation Q.2951 (OW95 COPYRIGHT Int

20、ernational Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling ServicesITU-T RECMN*Q-2953 95 m 4862593 0602882 514 Recommendation Q.2951 STAGE 3 DESCRIPTION FOR NUMBER IDENTIFICATION SUPPLEMENTARY SERVICES USING B-ISDN DIGITAL SUBSCRIBER SIGNALLING SYSTEM NO. 2 (DSS 2) -

21、BASIC CALL Geneva, 1995) 1 Direct-Dialling-In (DDI) 1.1 Scope This Recommendation specifies the stage three of the Direct-Dialling-In (DDI) supplementary service for the Broadband Integrated Services Digital Network (B-ISDN) at the TB reference point or coincident SB and TB reference point (as defin

22、ed in Recommendation 1.413 l) by means of the Digital Subscriber Signalling System No. 2 SS 2) protocol. Stage three identifies the protocol procedures and switching functions needed to support a telecommunications service (see Recommendation 1.130 2). In addition, this Recommendation specifies the

23、protocol requirements at the TB reference point where the service is provided to the user via an intermediate private B-ISDN. This Recommendation does not specify the additional protocol requirements where the service is provided to the user via a telecommunications network that is not a B-ISDN. Thi

24、s DDI supplementary service enables a user to call directly to another user on an ISDN private branch exchange (ISPBX) or other private systems, without attendant intervention. This supplementary service is based on the use of the ISDN number and does not include sub-addressing. The DDI supplementar

25、y service is applicable to all telecommunication services. This Recommendation is applicable to equipment, supporting the DDI supplementary service, to be attached at either side of a TB reference point or coincident SB and TB reference point when used as an access to the public B-ISDN. 1.2 Referenc

26、es The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; all use

27、rs of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. ITU-T Recommendation 1.413 (1993), B-ISDN user-n

28、etwork inter$ace. CCITT Recommendation I. 130 (1988), Method for the characterization of telecommunication services supported by an ISDN and network capabilities of an ISDN. ITU-T Recommendation 4.2931 (1993, Broadband Integrated Services Digital Network (B-ISDN) - Digital Subscriber Signalling No.

29、2 (DSS 2) - User network intelface layer 3 specification for basic callkonnection control. CCITT Recommendation E.164 (1991), Numbering plan for the ISDN era. ITU-T Recommendation 1.580 (1993) General arrangements for interworking between B-ISDN and 64 kbids based ISDN. CCITT Recommendation 1.25 l.

30、1 (1992), Direct-Dialling-ln. Recommendation Q.2951 (02/95) 1 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Services1.3 Definitions For the purposes of this Recommendation, the following definitions apply: 1.3.1 DDI number: It is that part of

31、 the ISDN number which is significant to an ISPBX or other private system. 1.3.2 user: The DSS 2 protocol entity at the user side of the user-network interface. 1.3.3 network: The DSS 2 protocol entity at the network side of the user-network interface. 1.3.4 ISDN number: A number conforming to the n

32、umbering plan and structure specified in Recommen- dation E.164 4. 1.3.5 international number: An ISDN number structured as specified in 3.2E.164 4 (in the paragraphs relating to international number). 1.3.6 national number; national significant number: An ISDN number structured as specified in 3.2E

33、164 4. (in the paragraphs relating to national significant number). 1.3.7 subscriber number: An ISDN number structured as specified in 3.2E.164 4 (in the paragraphs relating to subscriber number). 1.4 Abbreviations For the purposes of this Recommendation, the following abbreviations are used: B-ISD

34、N Broadband Integrated Services Digital Network DDI Direct-Dialling-In DSS 2 Digital Subscriber Signalling System No. 2 ISDN Integrated Services Digital Network IS0 International Organization for Standardization ISPBX Integrated Services Private Branch Exchange N-ISDN Narrow-band Integrated Services

35、 Digital Network 1.5 Description DDI numbers form part of the international numbering plan according to Recommendation E. 164. This Recommendation provides the flexibility to network operators to use national numbering plans of fixed or variable lengths. This flexibility also applies to DDI numbers,

36、 i.e. even within a given ISPBX or other private system, DDI numbers of different lengths may appear. In networks with an open numbering plan, the length of the DDI number is not necessarily known by the servicing local exchange nor by any other entity of the public network. DDI is provided when at

37、least a part of the ISDN number which is significant to the called user is passed to that user. These last digits (fixed or variable length) are sent from the exchange and received by the ISPBX or other private system by en bloc or overlap receiving, which finally and automatically establish a call

38、to the destination without the assistance of an operator. These last digits are sent in accordance with 5.21Q.2931, or 6.YQ.2931. 1.6 Operational requirements 1.6.1 Provisiodwithdrawal This service shall be provided after prior arrangement with the network operator and shall be withdrawn on the subs

39、cribers request or for administrative reasons. 2 Recommendation Q.2951 (OW95) COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicensed by Information Handling Services. 1.6.2 Requirements on the originating network side The basic call control procedures according to 5.UQ.2931,

40、 and 6.YQ.2931 are applicable. 1.6.3 Requirements in the network Not applicable. 1.6.4 Requirements on the terminating network side When the DDI supplementary service is provided to the called user, at least the DDI number shall be passed to the user in the called party number information element. T

41、he en bloc or overlap receiving procedure is used to transfer the called party number information according to the rules specified in 5.2/Q.2931, (en bloc receiving), or 6.YQ.2931 (overlap receiving). The destination network side may check the range and the format of the DDI number before it is pass

42、ed to the called user. 1.7 State definitions The states associated with basic call control according to Recommendation Q.2931 are applicable. 1.8 Coding requirements The DDI number is a part of the ISDN number which shall be inserted in the called party number information element coded as in 4.5.1 U

43、Q.2931. 1.9 Signalling procedures at the coincident SB and TB reference point Not applicable. 1.10 Procedures for interworking with private ISDNs 1.10.1 DDI number delivery 1.10.1.1 Normal operation The DDI number is delivered from the network to the called user according to the procedures of 5.2/Q.

44、2931, (en bloc receiving), or 6.YQ.2931 (overlap receiving). Where the addressing/numbering plan identification equals ISDN/teephony numbering pian (Recommendation E.164) the type of number is included in the called party number information element sent to the called user and shall be coded as: - un

45、known (see Table 4-14/Q.293 1, Note 2 against Type of Number”); or - subscriber number, national number or international number (see Table 4-14/Q.2931, Note 3 against “Type of Number”). NOTE - This coding is independent of the use of en bloc procedures (where the called party number is sent in a sin

46、gle message) or overlap procedures (where the called party number is sent in segments in several messages as it becomes available). 1.10.1.2 Exceptional procedures No exceptional procedures are required. 1.11 Interworking with other networks 1.11.1 Interworking with N-ISDNs This subclause specifies

47、the particular features to support access signalling interworking between B-ISDN and N-ISDN. The description of interworking assumes the communication scenario B as defined in Annex M.580 5. Recommendation Q.2951 (02195) 3 COPYRIGHT International Telecommunications Union/ITU TelecommunicationsLicens

48、ed by Information Handling ServicesInterworking N-ISDN + B-ISDN Not applicable. Interworking B-ISDN + N-ISDN The DSS 2 called party number information element is mapped to the DSS 1 called party number information element by the terminal adapter or interworking function by removing its second octet

49、and adjusting the length indication without causing other changes to the contents, and by respecting the order of this information element in the DSS 1 message. 1.11.2 Interworking with non-ISDNs No special requirements for interworking with other networks are necessary. 1.12 Interactions with other supplementary services 1.12.1 Connected Line Identification Presentation No interaction. 1.12.2 Connected Line Identification Restriction No interaction. 1.12.3 Calling Line Identification Presentation No interaction. 1.12.4 Calling Line Identification Restriction No inte