A Mechanism On Failure Detection And Recovery Based On MPLS

MPLS is a kind of packet forwarding method which utilizes tags to realize once-routing-multiple-exchanges.The combination of traffic engineering and MPLS can better solve the problem of uneven utilization of network resource due to invalid mapping of service flow and resources;can fast and accurate redistribute business flow based on the network topology,especially in the network failure.Therefore,MPLS technology is widely used in high-speed backbone network,and has a wide application prospect in mobile IP and voice transmission.MPLS-based failure restoration is also a hotspot.This thesis introduces the failure recovery technology and its principle of MPLS network,and summarizes the related research status.Generally speaking,the network failure is divided into two categories,and one is failure,the other is downgradation.From the perspective of failure recovery mode,failure recovery technology is divided into protection switching and rerouting.The former is through pre-establishing a recovery path to switch working traffic,and the advantage is fast and little packet loss,but cause a waste of bandwidth resources;the latter is establishing a new path on demand for restoring traffic after the occurrence of a failure,but the recovery is slow.Two kinds of failure as link failure and link degradation are solved in the thesis.According to the different failure types,different recovery strategies and schemes are put forward.The prototype system is implemented and tested.The main work of the thesis is as follows:(1)Proposes the MPLS network failure perception and recovery mechanism from the perspective of saving the network bandwidth resources,which is different from the protection switching of pre-establishing backup path,but the use of SNMP dynamic monitoring of the entire network state to timely aware of network failure,thus quickly rebuild the backup path and complete the path switch.(2)Two kinds of schemes as Hop_Routing and Source_Routing are proposed,which are combined with two kinds of path switching schemes.A suitable failure recovery solution has been found for each type of failure.(3)The MPLS network failure recovery system based on the SNMP and SSH is designed and implemented.Experiments show that the system can run normally and complete failure recovery,at the same time,can improve the utilization of network resources and reduce network congestion.