Localized QoS Routing with Admission Control for Congestion Avoidance

Localized Quality of Service (QoS) routing has been recently proposed for supporting the requirements of multimedia applications and satisfying QoS constraints. Localized algorithms avoid the problems associated with the maintenance of global network state by using statistics of flow blocking probabilities. Using local information for routing avoids the overheads of global information with other nodes. However, localized QoS routing algorithms perform routing decisions based on information updated from path request to path request. This paper proposes to tackle a combined localized routing and admission control in order to avoid congestion. We introduce a new Congestion Avoidance Routing algorithm (CAR) in localized QoS routing which make a decision of routing in each connection request using an admission control to route traffic away from congestion. Simulations of various network topologies are used to illustrate the performance of the CAR. We compare the performance of the CAR algorithm against the Credit Based Routing (CBR) algorithm and the Quality Based Routing (QBR) under various ranges of traffic loads.