Research On Failure Recovery With Diff-Serv Based On MPLS TE

With the development of network technology, more commercial applications started by the IP network to carry. Voice, video and other multimedia services are applied in the network, which requires a higher reliability and availability. IP protocol has certain robustness and survivability, multi-protocol Label Switching MPLS core using the network edge switching technology and network IP routing technology, network traffic is evenly distributed in the network, improve network performance. The existing recovery mechanism depends on the time of convergence, so it often fails to meet the requirements of business-critical and real-time traffic. The implementation of large networks using MPLS performance optimization become very convenient with failure recovery mechanism, therefore, MPLS fault recovery mechanism has became the key research of the MPLS traffic engineering.To ensure rapid recovery of services, LSP backup path need to pre-configure in MPLS fault recovery mechanism. In the heavy load mode, the backup path configuration will consume a large amount of available bandwidth resources, which leads to decline of the system performance. In order to balance the relationship of performance in the fast fault recovery network, Makam model, Haskin model, Hundessa model, Das model and Dyanamic model in existing network are analyzed in this paper. It points out that the existing network is not able to provide differentiated service with different levels in MPLS flows, so the high-level traffic flows decline much after recovery. Bandwidth of Low-level may also be occupied, so the QoS can not be guaranteed.In this paper, A new failure recovery algorithm TCD(Traffic Classes Differentiated failure recovery algorithm)is presented, It contains three parts:setting up the LSP state database; flow switch based on Diff-Serv; resource preemption based on Diff-Serv. In the initial stage, it establishes and maintenances the LSP state database, which contains LSPID, main path, backup path, flow properties and priority, and other link information. In the flow switching stage, the model discriminate varies flow by calling the database with different recovery. In resources preemption the stage, by enhancing the LSP resources controlling ability, let the LSR has the ability of the management of LSP bandwidth resources. The LSR choose the LSP with lower priority, while it was in preemption. LSR reduce their transmission rate to accommodate the new LSP’s bandwidth need. It choose to reduce the transmission rate in the LSR, the LDP will update LSP bandwidth in each LSR.The simulation results show that the new algorithm can reduce the recovery time, the number of lost packets and disordered packets, time delay after the resumption., ensure the bandwidth of high-grade traffic after the recovery, so the low levels business flow can not be subject to completely diverted. It can improve the utilization of network resources to ensure QoS of the various business flows.