Approximation Algorithms For Multipath Setup

It is desirable to allow packets with the same source and destination to take more than one possible path. This facility can be used to ease congestion and overcome node failures. One approach toward deploying multipath routing in the networks is by creating virtual paths, e.g. using MPLS. There are however costs associated with establishing and maintaining such virtual connections. In this paper, we present the formulation and an approximate solution for the problem of modeling, creation and optimization of the multiple paths in the networks. The aim is to minimize the cost of operating the network and maximize the utilization, using multiple paths. The polynomial-time approximation algorithm presented is based on mixed and linear programming formulation. This approximate solution has a constant approximation ratio; more precisely the throughput of the paths output by our algorithm is at least 0.14 of the optimum throughput, without exceeding the cost of the optimal solution.