Link selection algorithms for link-based ILPs and applications to RWA in mesh networks

RWA is a fundamental problem in the design and control of optical networks. We propose link selection algorithms that reduce the size of the link-based ILP formulation for RWA by pruning redundant link decision variables. The resulting formulation scales well to mesh topologies representative of backbone and regional networks. In our experiments, the new formulation decreases the running time by more than two orders of magnitude without any impact on optimality. The link selection techniques are general in that they may be applied to any optimization problem for which the ILP formulation consists of multicommodity flow equations as its core constraints.