An ILAN-ISDN gateway

The authors focus on a gateway design for the interconnection of ILAN (integrated local area network) and ISDN (integrated services digital network). A key question is how to maintain the quality of service for each class of traffic as guaranteed by both networks. The emphasis of the study is on the main issues involved in the interconnection of MAGNET (a network testbed at Columbia University) to PBX through a standard ISDN user-network interface. One issue, in particular, is the protocol conversion to resolve the incompatibilities, e.g. transforming voice between packet-switched form and circuit-switched form. A multilayer protocol conversion model is proposed which provides equivalent service at different layers for each class of traffic. Another issue is the development of a high-performance gateway architecture. A multimicroprocessor system architecture which exploits most parallel features in the execution of protocol conversion functions is also presented