Connection Level Active Rerouting in WDM Mesh Networks with Traffic Grooming Capability

In this paper, for the first time, we propose a novel rerouting approach which actively packs existing connections of different bandwidth granularities. Basically different from previously proposed active rerouting that blindly attempts to reroute many existing lightpaths, our algorithm at first estimates the potential resource gain of each existing connection and then reroutes only a small number of candidate connections that may give the largest gains. Therefore, it can efficiently reduce the rerouting costs, i.e., the required overheads and computations, while maximizing the amount of resources that can be conserved for future requests. Simulation results show that our approach keeps the rerouting costs at a low level but it can improve the blocking performance significantly.