Common channel signaling networks (CCSNs) play a central role in the delivery of a wide range of telecommunications services. In designing such networks, it is of paramount importance to have redundancy in CCS network elements (signaling points and signaling linksets) and to achieve architectural diversity in the transport network that provides bandwidth, transmission equipment, transport media, and physical structures to the CCSN. Such design considerations can help reduce the probability of occurrence or limit the scope of network outages due to traffic congestion and/or transmission equipment or transport facility failures. This paper contains a high-level discussion of issues relevant to the design of survivable CCSN architectures, provides a framework for CCSN survivability analysis, and presents novel heuristics that can be used to compute paths across the transport network on which to route signaling linksets, subject to diversity constraints that include combinations of "two-way diversity" and "three-way diversity." This first attempt at formally defining the topology design problem and formulating architectural diversity constraints for CCSNs can provide the technical basis for further CCSN survivability studies.>

Survivability of interoffice facilities of fibre-optic transmission networks is considered. A transport span protection strategy aimed at providing geographically diverse routing for protection systems is discussed. Algorithms based on shortest path heuristics have been developed to implement this strategy efficiently. Survivability measures are provided for evaluation of the effectiveness of this strategy. Some potential network failures are discussed, and the kind of protection that can be provided to interoffice facilities and equipment in order to minimize disruption of service is described. Numerical experiments on large-size networks are described.>