A Design Method of Logical Topology for IP over WDM Networks with Stable Routing

An IP (Internet Protocol) over WDM network is expected to be an infrastructure for the next–generation Internet by directly carrying IP packets on the WDM–based network. Among several architectures for IP over WDM networks, one promising way is to overlay a logical topology consisting of lightpaths over the physical WDM network, so that IP packets are carried using the lightpaths. The conventional design methods of the logical topology have been focusing on maximizing throughput of the traffic. However, when the WDM network is applied to IP, the end-to-end paths provided by the logical topology of the WDM network is not suitable to IP routing since IP has its own metrics for route selection. We therefore propose a new heuristic algorithm to design a logical topology by considering the delay between nodes as an objective metric. We use a non-bifurcated flow deviation method to obtain a set of routes that IP packets are expected to traverse. Our proposal is then compared with conventional methods in terms of the average packet