Asymptotic optimality of shortest path routing

Abstract : Many communication networks use adaptive shortest path routing. By this the authors mean that each network link is periodically assigned a length that depends on its congestion level during the preceding period, and all traffic generated between length updates is routed along a shortest path corresponding to the latest link lengths. It is shown that in certain situations, typical of networks involving a large number of small users and utilizing virtual circuits, this routing method performs optimally in an asymptotic sense. In other cases shortest path routing can be far from optimal.