The call control protocol in a separated call and bearer environment

The separation of call and bearer to support future teleservices and services in broadband networks is outlined in this paper. Various mechanisms to undertake the separation are overviewed and the method chosen by the International Telecommunications Union (ITU) and the European Telecommunications Standards Institute (ETSI) is described in detail. A full protocol model for broadband access signalling is derived and explained from the basic steps leading through to the establishment of an association between end-points supporting call control information flows. The call control protocol, currently being developed to establish, maintain and clear a call with more than one connection, is outlined and illustrated by information flows.