Implementation of current real time services (of which one of the more important is Voice over IP) on the current Internet face 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 utilizing the Widest-Shortest routing algorithm to provide QoS using different metrics. We show that this algorithm using a modified cost metric based on the hopnormalized is able to route real time traffic away from congested links thus providing acceptable jitter, end-toend delay and throughput to satisfy real time services requirements.
Ala F. Khalifeh, Ali H. El-Mousa