Survivability analysis of telephone access network

The telecommunications industry has achieved high reliability and availability for telephone service over decades of development. However, the current design does not aim at providing service survivability when a local switching office fails due to catastrophic damage. In this paper, several survivable architectures for telephone subscriber network are proposed based on common survivability principles. In order to quantitatively assess the effectiveness of design alternatives, a set of analytical models are developed to derive various survivability measures. Numerical results are provided to show how a comprehensive understanding of the system behavior after failure can be achieved through different survivability aspects.