This International Standard specifies the signalling protocol for the support of the Call Identification and Call Linkage Additional Network Feature (ANF-CIDL) at the Q reference point between Private Integrated Network Services Exchanges (PINXs) connected together within a Private Integrated Services Network (PISN).

CSA Preface Standards development within the Information Technology sector is harmonized with international standards development. Through the CSA Technical Committee on Information Technology (TCIT), Canadians serve as the Canadian Advisory Committee (CAC) on ISO/IEC Joint Technical Committee 1 on Information Technology (ISO/IEC JTC1) for the Standards Council of Canada (SCC), the ISO member body for Canada and sponsor of the Canadian National Committee of the IEC. Also, as a member of the International Telecommunication Union (ITU), Canada participates in the International Telegraph and Telephone Consultative Committee (ITU-T). This International Standard was reviewed by the CSA TCIT under the jurisdiction of the Strategic Steering Committee on Information Technology and deemed acceptable for use in Canada. (A committee membership list is available on request from the CSA Project Manager.) From time to time, ISO/IEC may publish addenda, corrigenda, etc. The CSA TCIT will review these documents for approval and publication. For a listing, refer to the CSA Information Products catalogue or CSA Info Update or contact a CSA Sales representative. This Standard has been formally approved, without modification, by the Technical Committee and has been approved as a National Standard of Canada by the Standards Council of Canada. Scope This International Standard specifies the signalling protocol for the support of the Call Identification and Call Linkage Additional Network Feature (ANF-CIDL) at the Q reference point between Private Integrated Network Services Exchanges (PINXs) connected together within a Private Integrated Services Network (PISN). ANF-CIDL is an additional network feature which allows the assignment of a Global Call Identification (GID) to identify a call end-to-end over the call route (i.e. between the two end PINXs). As an option, a Thread Identification (TID) may be assigned to different calls which are logically linked together due to the operation of other supplementary services and/or ANFs. Additionally a Leg Identification (LID) may be assigned, to identify the different legs of a call. NOTE 1 - This ANF has been developed to support the use of CSTA (ISO/IEC 18051) in a networked environment, i.e. in a PISN. Use of this ANF for other applications is not precluded. The Q reference point is defined in ISO/IEC 11579-1. Supplementary Service specifications are produced in three stages and according to the method specified in ETS 300 387. This International Standard contains the stage 3 specification for the Q reference point and satisfies the requirements identified by the stage 1 and stage 2 specifications in ISO/IEC 21888. The signalling protocol for ANF-CIDL operates on top of the signalling protocol for basic circuit switched call control, as specified in ISO/IEC 11572, and uses certain aspects of the generic procedures for the control of supplementary services specified in ISO/IEC 11582. This International Standard also specifies additional signalling protocol requirements for the support of interactions at the Q reference point between Call Identification and Call Linkage and other supplementary services and ANFs. This International Standard is applicable to PINXs which can be interconnected to form a PISN.