Service-sensitive Routing in DiffServ/MPLS networks

This study investigates the problem of unfairness when QoS routing does not consider the in ix of traffic classes. Unfairness is mainly caused by rout ing different traffic flows of the same class through paths with extremely different traffic mixtures, involving various service classes. Next, a new routing scheme-Service-sensitive Routing (SSR), which takes tile state of t raffic mixture of the various service classes into account, is proposed. To determine the QoS route for a flow request, SSR not only considers the ava ilable bandwidth and delay of tile candidate paths, but also considers the mix of traffic classes on the paths. Additionally, the hybrid granularity r outing decision in SSR scheme is scalable and suitable for the Differentiat ed Services and MPLS networks. Extensive simulations show that SSR can effe ctively reduce the variance of tile average of queuing delays, for example by approximately 20% to 35% for a moderate offered load, compared to tile s hortest path routing. Furthermore, this routing scheme reduces the fraction al reward loss and bandwidth blocking probability.