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 (fSO/IEC JTC1) for the Standards Council of Canada (SCC), the I S 0 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 TClT 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 Committee Administrator.) From time to time, ISO/IEC may publish addenda, corrigenda, etc. The CSA TClT will review these documents for approval and publication. For a listing, refer to CSA Information Products Catalogue or CSA Info Update or contact a CSA Sales representative. This Standard has been formally approved, without modification, by these Committees and has been approved as a National Standard of Canada by the Standards Council of Canada.
This International Standard specifies supplementary services Call Completion (SS-CC), which are applicable to various basic services supported by Private Integrated Services Network (PISN). Basic services are specified in ISO/IEC 11574.
SS-CC consists of two Supplementary services: the Completion of Calls to Busy Subscribers supplementary service (SS-CCBS) and the Completion of Calls on No Reply supplementary service (SS-CCNR). SS-CCBS allows completion of a call to a subscriber that was unsuccessful because of a busy condition and SS-CCNR allows completion of a call to a subscriber that was unsuccessful because the subscriber, although alerted, did not answer.
Supplementary service specifications are produced in three stages, according to the method described in CCITT Recommendation I.130. This International Standard specifies the stage 1 and stage 2 specifications of SS-CC. The stage 1 specifications (clauses 6 and 7) specify the supplementary services as seen by the users of PISNs. The stage 2 specification (clause 8) specifies the functional entities involved in the supplementary services and the information flows between them.