Routing in packet-switched communication networks

This paper addresses the problem of selecting a route for every pair of communicating nodes in a packet-switched communication network in order to minimize the average delay encountered by messages. A mathematical programming formulation of the problem is presented. An efficient solution procedure based on a Lagrangean relaxation of the problem is developed. Unlike most previous approaches where the best route for a communicating node pair is restricted to a set of prespecified candidate routes, our approach considers all possible routes for every communicating node pair. Our approach can also be used to generate good feasible routing schemes, whereas other approaches fail to generate feasible schemes beyond moderate levels of traffic. Extensive computational results across a variety of networks are reported. These results indicate that the solution procedure is effective for a wide range of traffic loads.