Performance Evaluation of VoIP using Shortest-Widest and Modified Widest-Shortest QoS Routing Algorithms

摘要

Implementation of current real time services (of which one of the more important is Voice over IP) on the existing Internet faces many obstacles; among them the issue of routing. Quality of Service (QoS) routing, attempts to provide real time services with the required guarantees to achieve acceptable performance. In this paper we study VoIP routing using the Quality of Service (QSR) network simulator. We investigate the Shortest-Widest routing algorithm and the Widest-Shortest routing algorithm that uses the hop-normalized metric to provide QoS for real time applications. We show that although both algorithms have superior performance compared with the conventional delay and hop based routing algorithms, the Widest-Shortest algorithm using a modified cost metric based on the hop-normalized metric is better able to route real time traffic away from congested links thus providing better performance to satisfy real time services requirements.