This Standard specifies supplementary service Recall (SS-RE), which is applicable to various basic services supported by Private Integrated Services Networks (PISN). Basic services are specified in ECMA-142.
SS-RE is a supplementary service which provides for the redirection of a call transferred by the served user back to the served user if the call is unanswered. SS-RE is only applicable after transfer by join, not after transfer by rerouteing.
Service specifications are produced in three stages, according to the method described in ETS 300 387. This Standard contains the stage 1 and stage 2 specifications of SS-RE. The stage 1 specification (clause 6) specifies the supplementary service as seen by users of PISNs. The stage 2 specification (clause 7) identifies the functional entities involved in the supplementary service and the information flows between them.