Vital nodes, interconnected infrastructures, and the geographies of network survivability

With an increased level of interconnection between critical network infrastructures, the potential for cascading actions that trigger both primary and secondary network failures are of great concern. Recent events, including the 2001 attacks on the World Trade Center, the blackout of 14 August 2003, and the Galaxy IV satellite failure 1998, have reinforced the need for a more thorough understanding of vulnerabilities relative to system performance. This article explores the topological complexities associated with network interconnections. In particular, we evaluate the potential impacts of losing critical infrastructure elements that are geographically linked. The loss of vital nodes, like telecommunication switching centers, is evaluated utilizing a developed spatial optimization model. Results indicate that certain infrastructure topologies are not particularly well equipped to handle the loss of vital nodes, whereas others could withstand the loss of such nodes and maintain an adequate level of service.