IP-Subnet Aware Routing in WDM Mesh Networks

We explore the problem of routing bandwidth guaranteed paths in wavelength-routed, WDM optical mesh networks. A WDM mesh network offers great flexibility in dynamically re-configuring this optical core to match the IP layer demands. In this paper, we argue that IP subnets can limit the re-configurability potential of the WDM mesh network. We show that finding the shortest IP-hop path, normally admitting a straightforward polynomial solution on the WDM mesh, is NP-hard in the presence of subnets. We propose a new algorithm called MobiTwist that finds the optimal shortest path when accounting for subnets.