Study On The Application Of IP FRR In OSPF Protocol

Along with the gradual integration of computer network and communication network, modernnetwork scale is more and more big. The new type networks appear constantly, and the complexityof the network is more and more high as well. Moreover, with the continuous improvement ofpeople’s living standard, consumers require more for the performance and quality of the network,especially in some voice and real-time applications. So, how to improve the service quality of thenetwork, make the network system operation stable and reliable, has become a hot research topic. IPFast ReRoute technology can calculates a backup route in advance. Detecting a fault, router doesnot immediately diffuse route information and calculate routes, and the use of backup route toreplace the failed one, so can reduce the interruption time and routing convergence time. Therefore,FRR has become the mainstream technology to improve network performance.Firstly, two link protection mechanisms: GR and BFD are introduced, and FRR technology andits principle are expounded in this thesis. Secondly, based on the research of LFA algorithm in FRRand backup next hop protection mechanism, six kinds of network environment are tested accordingto backup the next hop selection rules. Results prove that backup next hops selected in sixthnetworking modes is optimal.Testing results show that the best backup next hops can be selected bythe sixth backup next hops election scheme.For the application of FRR in OSPF protocol, two improved schemes are proposed. The firstscheme is to combine FRR and BFD. When a fault is detected by BFD, BFD will immediatelynotify the upper layer protocol to re-converge, improve the convergence efficiency andreduce interruption time. The second scheme is named as prefix-free convergence. The prefixiteration released the same device to the same next hop. After a link failure, we only need to changethe iteration of the next hop, through this way, the convergence time is reduced and the quality ofnetwork is improved.Finally, a test environment is set up at practice unit H3C Technologies Company, the proposalis tested and compared in the OSPF network supporting the algorithm of FRR. Results show thatusing the improved schemes of FRR, the flow loss is obviously improved, and the networkperformance is greatly improved as well.