BIER技术与双P圈保护方案研究

Study on the BIER Technology and Double P-Cycle Protection Scheme

为解决传统组播技术因组播树状态导致大量网络流量消耗以及低处理效率的问题,互联网工程任务组提出新型组播协议位索引显式复制(BIER)技术。该技术具有无状态可扩展优势,但缺乏配置简单且高性能的保护方案。为此,基于P圈保护算法和grow扩展算法提出双P圈保护方案,在网络拓扑中生成包含最短路径的P1圈和不包含最短路径的P2圈,采用双P圈进行联合保护,设计组播分组BIER封装条目格式并分析保护转发过程。在P4平台上对COST-239欧洲测量拓扑进行了仿真,结果显示,相较于传统P圈保护方案,双P圈保护方案的平均节点保护成本下降了30.8%,网络报文丢失概率下降了16.6%。双P圈BIER保护方案不仅可行,而且降低了组播保护成本,提高了故障保护率。

In order to solve the problem of traditional multicast technology that consumes a lot of network traffic and reduces processing efficiency due to the status of the multicast tree,IETF proposed a new multicast protocol named Bit Indexed Explicit Replication(BIER)and the forwarding mechanism of BIER technology has the advantage of stateless scalability,but it lacks a simple and high performance protection scheme.Based on the p-cycle protection algorithm and the grow algorithm,a BIER protection scheme is pro⁃posed which uses the P1-cycle including the shortest path and the P2-cycle not including the shortest path.That is the double p-cycle joint protection,which decreases the cost of BIER multicast protection and increases the ratio of failure protection.In addition,the item format of the multicast BIER packet encapsulated by the algorithm and the forward process of protection are also given.By the pro⁃gramming protocol-independent packet processors(P4)platform,the simulation results of the COST-239 European survey topology show that compared with the traditional P-cycle protection scheme,the average node protection cost of the double P-cycle protection scheme has dropped by 30.8%and the network packet loss probability has dropped by 16.6%.The double P-cycle BIER protection scheme is not only feasible and effective,but also reduces the cost of multicast protection and improves the failure protection rate.