The Research Of The Graceful Restart And Non-stop Forwarding Technology Of The MPLS Network

With the advantages like fast forwarding, high quality service and multiple services, Multi-Protocol Label Switching (MPLS, Multi - Protocol Label Switching) technology plays an increasing important role in the current network. Especially in the operators, bank, moderate nets, it has been widely used. The high availability of MPLS network gradually becomes the research object of the corporation and the college. The high availability of the MPLS network includes the fast fault recovery, fast fault detection and data non-stop forwarding, etc. Label Distribution Protocol (LDP, Label Distribution Protocol) which is designed as the MPLS custom control signaling protocol, is widely used in the MPLS network.Th e hardware of current router equipment constantly improves its performance. The Dural Master router is more widely used especially as the key node in the network. When the router master failures, the function of protocol controlling layer will be affected, and neighbors will perceive this kind of problem. The protocol'flap will cause the network to flap. But the emergence of Dural Master router provides solutions for such conditions.Through the studies of the technology to improve the high availability, this thesis summarizes the methods to increase the availability of the MPLS network. At last, it studies the Graceful Restart technology and the Non-stop Forwarding technology, and the implement them. This thesis mainly has the following several aspects of the results:1. Realize a kind of method for LDP supporting the Graceful Restart technology based on the distributed and Dural Master router. According to the LDP Graceful Restart specification, through a detailed study of the functional requirements, this thesis designs module service registration and notification to activate the Graceful Restart. So get the goal to reduce the MPLS flow's interruption during the master-to-slave switching.2. Design a scheme to realize MPLS supporting Non-stop Forwarding technology based on the distributed and Dural Master router. According to a manufacturer's current equipment system architecture and the Non-stop Forwarding technology specification, this scheme has been finished. Through listening the change of the master control card, the backup master card updates its information database in real time, and through the two ways of the batch synchronization and real-time synchronous to ensure the accuracy and the completeness of the backup information.3. Put forward a kind of the realization method to combine the LDP Graceful Restart and MPLS Non-stop Forwarding. LDP Graceful Restart guarantees the neighbors send the same label to the restart router after the master-to-slave switching. At the same time, the Non-stop Forwarding backup the distributional label information from the master card. The conbining realizes the MPLS flow's non stop forwarding during the master-to-slave switching.