prSSH ETS 300 358:1995 ed.1

Integrated Services Digital Network (ISDN); Completion of Calls to Busy Subscriber (CCBS) supplementary service; Functional capabilities and information flows

Scope

This European Telecommunication Standard (ETS) defines the stage two of the Completion of Calls to Busy Subscriber (CCBS) supplementary service for the pan-European Integrated Services Digital Network (ISDN) as provided by European public telecommunications operators. Stage two identifies the functional capabilities and the information flows needed to support the service as described in stage one. The stage two description also identifies user operations not directly associated with a call (see CCITT Recommendation I.130 [3]). This ETS is specified according to the methodology specified in CCITT Recommendation Q.65 [6]. This ETS does not formally describe the relationship between this supplementary service and the basic call but, where possible, the information is included for guidance. In addition, this ETS does not specify the requirements where the service is provided to the user via a private ISDN. This ETS does not specify the requirements for the allocation of defined functional entities within a private ISDN; it does however define which functional entities may be allocated to a private ISDN.