Research And Realization Of OAM Technology In Multi-protocol Label Switching Network

Multi-protocol Label Switching(MPLS)-based networks is the key bearer technology of the scalable next generation networks, and the foundation of cost-effective, highly reliable multi-service IP network. The need for monitoring and trouble shooting capabilities of end-to-end MPLS network connectivity rises, because the number of network operators which converge amounts of data and access services onto a common MPLS-based network infrastructure is increasing.OAM technology of MPLS network has emerged, which is a kind of detection and management mechanism for Label Switching Path(LSP) connectivity that is independent of any OAM functionality in other layer networks, allows the defect management of MPLS layer networks get rid of the dependence of control-plane. Additionally, MPLS OAM technology has the capacity to ease MPLS network operations, improve network availability to ensure service quality and reduce network operating costs.The basic principle of MPLS OAM is periodically sending OAM connectivity detection packets (CV/FFD packet) from head-end of LSPs, and real-time monitoring of packets at the tail-end. Once tail-end detect defect of LSPs, it will send BDI packet with defect information to the head-end through backward path which is binded with the LSPs being deteced. The head-end receives the defect notification packet and start protection switching. Finally accomplish the management, detection and maintenance of the transmission paths in MPLS network.This paper focus on the research of OAM mechanism in MPLS networks :1,Firstly learn the basic principles of MPLS OAM mechanism by analyzing the recommendations such as ITU-T Y.1711. Then achieves MPLS OAM mechanism by designing sub-module on the basis of the actual situation under the existing system platform.2,Secondly with the background of System platform, simplify the work processes of the MPLS OAM function block into two parts: the process of connectivity detection for MPLS OAM and the process of OAM protection switching. The connectivity detection process is divided into two parts: packets send/receive treatment and end nodes treatment.3,Finally make improvements of sending/receiving messages process by using the combination of synchronous with asynchronous SOCKET based on the original system sub-module.Based on the above researches, manually configure a small network to simulate MPLS network environment, do feasibility analysis and verification for all above proposals.