Dynamic routing for shared path protection in multidomain optical mesh networks

The routing problem for shared path protection in multidomain optical mesh networks is more difficult than that in single-domain mesh networks due to the lack of complete and global knowledge of the network topology and bandwidth allocation. To overcome this difficulty, we propose an aggregated network modeling by underestimation with a two-step routing strategy. In the first step, a rough routing solution is sketched in a virtual network that is the topology aggregation of the multidomain network. A complete routing is then determined by solving routing problems within the original single-domain networks. The first step can be solved by either using an exact mathematical program or a heuristic, whereas the second step is always solved by heuristics. Computational results show the relevance of the aggregated network modeling. They also prove the scalability of the proposed routing for multidomain networks and its efficiency in comparison with the optimal solution obtained by use of the complete information scenario. In addition, we believe that short working paths lead to a higher possibility of sharing backup resources between backup paths. Our mathematical program model minimizes the total requested resources and at the same time provides a short working path, resulting in a further overall saving of resources.