Distribution of protocol functions in an interworking-based ISDN access implementation

Although the fundamental premise behind the Integrated Services Digital Network (ISDN) is the provision of a variety of communication services using a single integrated digital network, it is clear that many initial ISDN implementations will be based on the interworking of existing dedicated networks and switching products. Within such implementations, it is possible to distribute the access protocol and service functions required to provide an ISDN access interface amongst the various interworking components which comprise the implementation. This paper provides a systematic approach for determining the various function distribution alternatives which may be used to provide an interworking-based ISDN access implementation.