Supporting End-to-End QoS in DiffServ/MPLS Networks

In MPLS networks, the higher-priority LSP (Label Switching Path) will preempt the resource of lowerpriority LSP when its bandwidth resource is limited. At the time, the lower-priority LSP is destroyed, and its bandwidth resource is released to the higher-priority LSP. The destroyed path has to be rerouted by selecting another LSP; the new LSP maybe quickly suffer another bandwidth resource preemption again. If this scenario occurs frequently, routers would be subjected to the superfluous overload, and the quality of delivering flow can not be guaranteed. In paper [15], we had proposed a new policy to avoid the preemption because of flow priority and load balancing in the MPLS networks. In this paper, the policy supports the end-to-end QoS in DiffServ-aware MPLS networks will be discussed. Moreover, many simulations are done to compare the QoS of all service levels in DiffServ which Constraint-based Routed (CR) scheme includes the new policy in paper [15]. The simulation results indicate that the adding our policy to CR is better then the traditional CR.