Optimizing link weight in OSPF routing under unknown traffic matrices

An important traffic engineering problem for OSPF networks is the determination of optimal link weights. In this paper, we assume that the traffic matrix, which specifies traffic load between every source-destination pair in the network, is unknown and varies with time, but that always lies inside an explicitly defined region. Our goal is to compute an optimal link weights that minimizes maximum link utilization for all traffic matrices inside the bounding region. We first present a mixed-integer programming formulation to compute the optimal link weights. We then present a heuristic algorithm to find the optimal weights. Our simulations show that the proposed algorithm not only performs better than existing weight setting schemes in terms of minimizing congestion ratio, but also can achieve solution which is close to the optimal solutions.