Call party handling aspects evolution from IN CS-2 to IN CS-3

The call party handling (CPH) approach was introduced in the ITU-T recommendations for intelligent network (IN) Capability Set 2 (CS-2) to cater for services where one party can participate in several calls. These services: call wait, call forwarding, call transfer, three-way calling, usually involve more than two parties i.e. require instantiation of multiple basic call managers (BCM) for one party, and the CPH´s role is to facilitate IN control of those multiple instances. Since the CPH acts only under IN control, the entity implementing CPH, IN-SSM, resides entirely in the SSF. IN support for B-ISDN is planned for IN CS-3 and IN CS-4. We propose an enhanced CPH structure to model B-ISDN calls. A call/connection separation model is proposed in order to allow the non-exhaustive following list of operations: (i) add and drop parties within a multiparty call, (ii) add and drop parties within a point to multipoint connection, (iii) add, modify and drop bearer connections within a multiconnection call, (iv) call establishment without connection, (v) connection establishment by another party within a call (third party connection setup), (vi) initiate connection attempt