Design of a signalling server for the support of multipoint-to-multipoint calls through standard B-ISDN signalling protocols

CSCW applications often require broadband network infrastructures able to support multipoint-to-multipoint configurations. Current B-ISDN signalling standards only provide unidirectional multicast communication. Following the principle of re-using as much as possible existing standardised protocols, multipoint-to-multipoint capability can be achieved as a mesh of correlated point-to-multipoint connections introducing some new control functionality. Control functionality foresees the invocation of suited remote operations through the generic functional protocol transport mechanism. After the description of the proposed approach to the multipoint-to-multipoint call, the paper describes the design and the implementation of a functional entity, called signalling server, capable to handle it. This paper is partially based on the results of the ACTS project AC012 MULTICUBE. It is worth highlighting that signalling server implementation is successfully running in MULTICUBE's trials.