A Framework for Characterizing Disaster-Based Network Survivability

This paper formulates a general framework that includes and extends the existing definitions for network survivability. Based on this framework, network survivability is characterized by a survivability function rather than a single-value survivability measure, and various quantities of interest can be derived from the function. Examples are the expected survivability, the worst-case survivability, the r-percentile survivability, and the probability of zero survivability. The survivability function is especially useful for the study of large-scale disasters. For illustration, we derive the survivability function in closed form for a simple ring network under link failures. We also discuss the general procedure for finding survivability functions for complex networks, and show that the survivability function reveals useful information about a network. This framework provides a unified and practical approach to analyzing and desianina highly survivable communications networks.