Survivable virtual topology design for single-node failure

In IP over WDM networks, a single failure in the WDM layer breaks down multiple IP links and may leave the virtual topology disconnected. This will make the restoration by the IP layer impossible, which must be avoided by suitable virtual topology design. In this paper, we focus on single-node failure and develop a Remove-Node Algorithm to map IP links on lightpaths in such a way that the IP topology remains connected after the failure of any node in the WDM topology. We prove the validity of the algorithm and give out simulation results at last.