The use of demand-wise shared protection in creating topology optimized high availability networks

In order to meet the availability requirements of modern communication networks, a number of survivability techniques were developed that adapt the demand-wise shared protection network design model to incorporate strategies increasing network availability. The survivability methodologies developed took two approaches. The first approach incorporated availability directly into the network design model. The second approach ensured minimum dual failure restorability was set within the model. These methodologies were developed for predetermined topologies, as well as to have topology optimization incorporated into the model.;All methodologies were implemented and analyzed on a set of samples. The analysis examined the cost, topology and actual availability of the network designs. Availability design was effective but computationally intensive and difficult to design. Minimum dual failure restorability was also effective in increasing availability with a significant caveat. Designing for dual failure restorability increased traffic exposure to possible failures, and without sufficient levels of dual failure restorability could have a negative impact on availability.