Delay considerations in multicast routing for ATM networks

The main elements that contribute to the delay through an ATM network are the fixed switching delay of the nodes, the propagation delay experienced between nodes and the queuing delay encountered for the inter-node links. To minimise the propagation delay, a shortest path (SP) routing strategy is appropriate from which a broadcast SP tree can be built with a delay bound equal to the longest delay from the source. The authors show that, where link costs are proportional to propagation delay costs, a modification to Dijkstra´s SP algorithm can give a more efficient solution than the original Dijkstra algorithm. Results presented for both randomly generated networks disregarding delays at the nodes and for simulated ATM networks