Optimized routing adaptation in IP networks utilizing OSPF and MPLS

In this paper routing adaptation methodologies are investigated, which utilize conventional routing protocols such as OSPF in combination with MPLS. While having the majority of traffic routed along optimized shortest paths, MPSL is only partly introduced to complement the adaptation process. We present a novel algorithm based on simulated annealing to optimize link metrics in OSPF networks. The algorithm takes into account the original routing configuration and allows tradeoff considerations between routing optimality and adaptation impact. For the setup of complementary MPLS paths, two mixed-integer programming models are proposed. It can be shown that already a relatively small number of MPLS paths is sufficient to greatly improve a network's quality of service.