Research On Fault Detection And Recovery Scheme Of MPLS-Based Network

As the two most common applications for service providers in the public network infrastructure to be configured, MultiProtocol Label Switching(MPLS) and MPLS VPN technologies have been widely used. The continuous development of the real-time service such as image transfer, video conference and VoIP requires higher service quality of MPLS VPN. To keep high efficiency and stability of the network in case of the failure, a lot of research works have been done by both organizations and individuals to quickly detect the network fault and recover from this failure.In practical applications, the detection mechanism of the IP-based routing protocol is commonly used now, which would take one second or more to detect the failure. The detection times(the time to detect failures) are no better than a second, which would probablely result in losing a great deal of data packets and causing great losses. Bidirectional Forwarding Detection(BFD) is a unified detection mechanism in the whole network which is used in lightweight level's and can rapidly detect the communication failures between adjacent systems. It can provide a universal,standardized,media-free and protocol-free mechanism of fast detection. It runs on top of any data protocol,such as routing protocol and MPLS,which can be used to detect failures in the bidirectional forwarding path between adjacent forwarding engines. For the MPLS VPN network, we hope to find out a detection mechanism like this to reduce the detection times to millisecond level and a fast recovery scheme,meanwhile saving the network resource.Based on this technology and application background, this paper does some works about fault detection and recovery in MPLS VPN-based network as follows:1. Study the theoretical knowledge about the protocol stardards of MPLS, BFD and the technology of MPLS VPN in depth, and analyze the possibility of using BFD for detecting the MPLS VPN-based network;2. Achieving the function of using LSP Ping for boot-strapping the BFD session and the periodic traceroute by adding command-line in the configuration module. Design BFD for Label Switching Path(LSP) of MPLS VPN-based network through process design, module interaction design and operation design;3. Realized the BFD for LSP scheme by the network simulation software;4. It needs a better scheme for fault recovery after the network is detected by MPLS. After comparing the two recovery solution between path protection and local protection, I prefer to the local protectin as the basement schme because of its better recovery performance. Then, this paper propose two bandwidth sharing schemes.The first one is backup-backup bandwidth sharing and the second one is primary-backup bandwidth sharing. Then research the two schemes following;5. Based on bandwidth sharing schemes mentioned above, combined them with preemptive priority level, this paper provides the formula for calculating the bandwidth.6. Introduce the concept of traffic enginee(TE) to MPLS VPN-based network, which enables the LSP using Label Distribution Protocol(LDP) across the RSVP TE region and makes TE available to MPLS VPN services. So that the parameters needed to calculate the bandwidth can deliver through RSVP message and lastly optimize the allocation of bandwidth resource.