CAN/CSA-ISO/IEC 13865-97 (R2001)

The international community has decided to make this standard available only in the English language version. It has been adopted as a National Standard of Canada on this basis. This National Standard of Canada is equivalent to International Standard ISO/IEC 13865:1995. 1 Scope This International Standard specifies Supplementary Service Call Transfer (SS-CT), which is applicable to various basic services supported by Private Integrated Services Networks (PISNs). Basic services are specified in ISO/IEc 11574. SS-CT is a supplementary service which enables a user to transform two of that user's calls (of which one must be answered) into a new call between the other two users of the two calls. Supplementary service specifications are produced in three stages, according to the method described in CCITT Recommendation I.130. This International Standard contains the stage 1 and stage 2 specifications of SS-CT. The stage 1 specification (clause 6) specifies the supplementary service as seen by users of PISNs. The stage 2 specification (clause 7 and 8) identifies the functional entities involved in the supplementary service and the information flows between them. The International Standard contains two stage 2 specifications reflecting different ways of operating the service within the network: transfer by join and transfer by rerouteing.