Survivable routing in WDM networks with guaranteed minimum network bandwidth

Abstract

In IP over WDM networks, IP links are realized by subscribing to lightpath services from a WDM network. Survivability is a key issue in designing such networks. There are two kinds of Lightpath services available: protected and unprotected. The research in [3] mainly considers the cases in which the only constraint is that the IP network remains connected after any single fiber-link failure. The problem was formulated into a mixed integer linear programming (MILP) problem. This thesis considers the additional requirement of a minimum survivable network bandwidth, and incorporates this as a criterion into the network design. First a new MILP formulation is proposed which satisfies the minimum survivable network bandwidth requirements. In addition, the computational requirement for the MILP is measured in simulations. Simulations show that the MILP has reasonable computation costs for small to moderate size networks. These costs increase with the increase of survivable bandwidth requirements.