Research On The BFD-based Technology For MPLS TE Network Linear Link Protection Switching

Nowadays,with the great expanding of network scale and the diversification of network applications,when the network fault occurs suddenly, in order to make no difference to the business,it requires the network to detect and recover from the fault rapidly and accurately. At present, a high percentage of the network architecture are based on TCP/IP protocol.Therefore there is no guarantee of recovery time when the network fault occurs,and it just provides a best-effort service.MPLS is a technology which use labels to forward data traffic high-speed and efficiently,and it can realize the function of TE and QoS.The reliability of the network is so important that the fault detection based on IP protocol is not acceptable. We must come up with a more rapid and lightweight detection mechanism. The research of MPLS network fault detection is a hot issue currently.Bidirectional Forwarding Detection(BFD) protocol provides a simple and lightweight method for fault detection. Compared with the traditional fault detection of "Hello" mechanism, it can detect network fault in milliseconds, which can more adapt to the rapid growth of network requirements. As one of the best fault detection solutions, BFD can greatly improve the rate of network fault detection.The BFD-based fault detection mechanism is applied to detect the faults in MPLS TE network.Meanwhile, MPLS LSP-Ping mechanism is also introduced into the fault detection solution in order to make the fault location more accurate and user’s operation simpler.In the aspect of the recovery of MPLS TE tunnel fault,this paper mainly use a way of creating protecting rearrangement group to protect the main tunnel. When the detection mechanism detects a tunnel fault, the system will switch the traffic to its backup tunnel. And the network can be recovered rapidly in this way.According to the BFD-based fault detection and recovery solution, a BFD-based network fault detection and recovery system is designed and implemented. Test results reveal that the system can satisfy the design requirements. The system has been successfully applied to a practical project, which further verify the correctness and efficiency of the BFD-based fault detection and recovery solution proposed in the thesis.