Developing scalable protocols for three-metric QoS routing

Quality of service (QoS) based routing provides QoS guarantees to multimedia applications and an efficient utilization of the network resources. Nevertheless, the QoS-routing algorithm must be simple because a costly procedure does not scale with the size of the network. This paper proposes and analyzes the performance of the single mixed metric (SMM) routing protocol in two versions: one based on distance-vectors and the other on link-states. SMM takes into account three metrics: propagation delay, available bandwidth, and loss probability. A heuristic based on the residual loss probability and metric-combination is used to turn the algorithm scalable and solvable in polynomial time. The simulation results show that SMM outperforms other solutions that implement QoS routing based on three metrics. (C) 2002 Elsevier Science B.V. All rights reserved.