Performance of dynamic multi-layer routing schemes in IP+optical networks

This paper presents two dynamic multi-layer routing policies for optical IP networks. Both policies first try to allocate a newly requested electrical path to an existing optical path that directly connects the source and destination nodes. If such a path is not available, the two policies employ different procedures. Policy 1, which has been published already, tries to find available existing optical paths with two or more hops that connect the source and destination nodes. Policy 2, which is proposed in this paper, tries to establish a new one-hop optical path between source and destination nodes. The performance of the two routing policies is evaluated. Simulation results suggest that policy 2 outperforms policy 1 if p is large, where p is the number of packet-switching-capable ports p; the reverse is true only if p is small. We observe that p is the key factor in choosing the most appropriate routing policy.