基于段路由的单节点故障路由保护算法
Single node failure routing protection algorithm based on segment routing

针对已有的路由保护方案没有很好权衡路由保护算法的故障保护率和路径拉伸度之间的关系，该文提出了一种基于段路由（SR）体系结构的快速重路由算法IPFRRBSR。IPFRRBSR为每个源-目的对计算两条路径，其中一条是最短路径，另外一条是利用段标签构造的备份路径。当网络没有故障时利用最短路径转发报文，当网络出现故障时利用备份路径转发报文。最短路径和备份路径（除去源和目的）没有公共节点，因此二者几乎不会同时发生故障。实验结果表明：该算法不仅可以应对网络中任意的单节点故障情形，并且具有较小的路径拉伸度。
Abstract：Existing routing protection schemes do not accurately consider the relationships between the failure protection ratio and the path stretch. A simple IP fast reroute based on the segment routing (IPFRRBSR) algorithm is given here to consider these relationships. IPFRRBSR calculates two paths between each source-destination pair with one being the shortest path and the other being a backup path constructed using segment labels. The packets are forwarded along the shortest path when the network is in the normal state, but are forwarded along the backup path when a network failure occurs. Since the shortest path and the backup path (except for the source and destination nodes) do not have any common nodes, the probability of them failing simultaneously is very low. Tests show that IPFRRBSR can deal with single node failures in the network and has a small path stretch.