基于逐跳方式的单链路故障保护算法

摘要

When a link fails,the deployed intra-domain routing protocol need to re-convergen.During the process of re-convergence,packets which travel through the link will be dropped.Therefore,IETF proposed a framework,named IPFRR (IP Fast Re-Route),which can effectively reduce packet loss when a single-link failure occurs.However,IPFRR cannot provide complete protection against all single-link failure scenarios.Based on the framework,lots of IP-tunnel-based schemes have been proposed to solve the problem.However,these methods introduce extra overhead and need the assistance of an auxiliary mechanism.In this work,we aimed for hop-by-hop routing algorithm that can provide complete protection against all such single-link failure scenarios.%当网络中的某条链路出现故障时,互联网部署的域内路由协议需要重新收敛,在收敛过程中经过该链路的报文将会被丢弃.针对该问题,IETF(the Internet Engineering Task Force)提出了快速重路由保护框架,利用该框架可以有效地解决网络中单链路故障造成的报文丢失问题,然而该方案并不能完全保护网络中所有可能的单链路故障.基于该框架研究者提出了一种基于隧道的解决方案,该方案虽然可以提供100%的单链路故障保护,但是需要辅助机制的协助,开销较大,难以实际部署.因此,提出了一种基于逐跳方式的针对单链路故障的全保护方案,该方案可以解决网络中任意的单链路故障造成的报文丢失问题.