Survivable Overlay Layout of IP Over WDM

Abstract

Wavelength Division Multiplexing (WDM) technology's capacity of providing very wide bandwidths in optical transport network makes it a good choice to meet the exponential growth of Internet traffic. We consider the problem of routing the Internet Protocol (IP) network over the WDM network in such a way that the IP network is still connected under physical failures. We call such a routing survivable. We formulate the survivable routing problem dealing with any single fiber cut as a Mixed Integer Linear Program (MILP), which is a modified version of the Integer Linear Program (ILP) in [1]. We route various IP networks over a number of WDM networks to show the dramatic run-time improvement of this MILP compared to the ILP in [1]. We also consider the survivable routing problem dealing with multiple link failures that are referred to as a shared risk link group. Finally, we study a scenario where we design a IP network based on a traffic matrix, and then overlay the IP network over the WDM network.