Flow Splitting Approach for Path Provisioning and Path Protection Problems

We consider off-line versions of path provisioning and path protection problems for general circuit switched networks. Both problems deal with a given network topology and a list of integral demand flows. The objective is to route the flows and to allocate the bandwidth in a way that minimizes the total amount of bandwidth used for working and protection paths. We consider path-based protection where, in case of a single link failure, all the flows utilizing the failed link can be rerouted to a precomputed set of paths. We demonstrate that flow splitting can bring significant advantages for both provisioning and protection problems. Since the problem is NP-complete, we propose and analyze two simple heuristics. We show that one of these heuristics performs almost as well as the optimal solution.