Traffic-based survivability analysis of telecommunications networks

We define a class of traffic-based survivability measures and perform a survivability analysis of telecommunications networks based on these measures. We consider networks with and without restoration separately. For networks without restoration, we evaluate the traffic-based measures in polynomial time. For networks with restoration, we consider a preplanned restoration scheme and provide a method to calculate upper and lower bounds of the traffic-based measures in polynomial time. We show the effectiveness of the bounds through an example. In the preplanned version, rerouting tables for a selected set of failure scenarios (also called covered states) are computed off-line and preloaded into each node. When a failure occurs, nodes detecting or informed of the failure load appropriate rerouting tables to reroute as much affected traffic as possible. The preplanned version achieves better utilization of spare capacity for covered failure states and is suitable for situations where short restoration time is required.