Diverse routing for improving the survivability of the optical Internet

The task of finding a physically disjoint protection path from a working path to guarantee service continuity during the occurrence of failures has been one of the most important issues for improving survivability of the optical Internet. To achieve a global optimal, working and protection paths are required to be optimized at the same stage and have asymmetrical weightings on the two paths when shared protection scheme is adopted. In this paper, we focus on the study of finding asymmetrically weighted optimal node-disjoint path-pairs for optical networks, so that the network performance in terms of success rate of building up disjoint path-pairs and the average restoration time is optimized. We first propose and examine a novel heuristic algorithm to solve the diverse routing problem, which is based on the Sub-Optimal Path-Solver (SOPS), a new method for finding loop-less K-shortest paths. Then a simulation-based study on the weighting parameter of working paths versus network performance is conducted and results are reported.