Preliminary availability objectives for broadband ISDN using next generation switching and various interconnection topologies

The authors propose preliminary availability objectives for a fully broadband network based on proposed network architectures, chosen as hypothetical reference connections (HRCs). They detail the last stage of a three-stage evolutionary plan for broadband integrated services digital network (BISDN) implementation that incorporates next generation switching (NGS) systems and various interconnection topologies. They calculate the direct effect of switching and interoffice topologies on the overall service availability objective. They show that the overall network-level availability objective for the assumed architecture can be up o 99.98% (105 min/yr unavailability) because of the proposed improvements in availability of NGS systems and the proposed implementation of more survivable architectures in both switching and the interoffice. They also show the potential for reliability improvement using various proposed BISDN architectures