Study And Implementation Of LDP Fast-Reroute

MPLS is widely used in VPN, Traffic Engineering, QOS and so on, its good scalability made it possible to provide customers with a variety of services in an unified MPLS/IP base network architecture. MPLS is becoming a basic technology of large scaleble networks and many large operators use MPLS technology to build public tunnels on their backbone network for forwarding services. In order to provide reliable service, MPLS failure recovery technologies have become research focuses.LDP is one of the main signaling protocols of MPLS, and Fast Re-route is the core technology of MPLS failure recovery. This thesis firstly studied on three LDP Fast Re-route schemes, they are Kini scheme, MRT-LDP-MT scheme and IP-FRR-Based scheme, gave a brief introduction of principle of these three schemes, a detailed analysis of their realization and a cursory analysis of their performance. After comparing advantages and disadvantages of these three schemes and considering current software environment, this thesis chose IP-FRR-Based scheme to implement LDP FRR.This thesis discussed the detail about how to realize the backup management function and failure switching function based on the original LDP module. Backup management made some extensions to LDP module to make it has the ability to handle multiple routes, and manage backup labels and switching of status of labels. Failure switching deals with the failure information proposed by the system and BFD module, switches primary labels and backup labels when failure happens. At last gave a test to LDP FRR with use of eNSP developed by FIUAWEI company, verified that software entries of LDP module can change correctly along with the route. Failure recovery time of dealing with failure information proposed by the system is30ms-50ms and for BFD is200ms-300ms, has the function of Fast Re-route.