Internet QoS Routing Using the Bellman-Ford Algorithm

Multimedia applications are Quality of Service (QoS) sensitive, which makes QoS support indispensable in high speed Integrated Services Packet Networks (ISPN). An important aspect is QoS routing, namely, the provision of QoS routes at session set up time based on user request and information about available network resources. This paper develops optimal QoS routing algorithms within an Autonomous System (AS). Previous approaches have been based either on minimizing a single metric (delay, for instance) or a combination of multiple metrics, optimizing one at a time, in a hierarchical fashion. Our approach nds minimum hop paths which satisfy multiple QoS constraints. We argue that a QoS version of the Bellman-Ford routing algorithm provides the best strategy for QoS routing problems of a given type. We show that Bellman-Ford is very powerful in solving most multiple constrained routing problems arising in a at network (within an autonomous system), if the minimum hop is the main objective function. We further illustrate the importance of Bellman-Ford QoS routing algorithms with regard to network utilization and session blocking through simulation experiments.