一种跨层共享保护单播路由机制

Cross-layer shared protection unicast routing mechanism

为了减少IP over WDM光互联网中发生故障时受影响的业务数,提出了一种跨层共享保护单播路由机制.该路由机制可以在稀疏波长转换和光收发器数等多约束条件下,通过建立多层辅助图将多约束问题转换为图论问题,为业务在IP层提供保护,同时为重负载工作光路提供WDM层保护.此外,为了提高资源的利用率,提出了一种资源共享策略.根据共享资源的粒度,该资源共享策略可以分为逻辑链路保护资源共享策略和波长链路保护资源共享策略.基于欧洲教育科研网GEANT拓扑的仿真结果表明,与专用保护单播路由机制相比,所提路由机制具有更低的阻塞率和更高的负载均衡度,能够有效解决光网络生存性问题.

In order to reduce the amount of the impacted traffic due to failures in the IP（ internet protocol） over WDM（ wavelength division multiplex） optical Internet,a cross-layer shared protection unicast routing mechanism is proposed. Under the multiple constraints,such as sparse wavelength conversion and the number of optical transceivers,the proposed mechanism can provide protection for the traffic in the IP layer and the heavy-loaded working lightpath in the WDMlayer by transforming the multi-constraints problem into the graph theory problem through building the multilayer auxiliary graph. In addition,a resource sharing strategy is introduced to improve the resource utilization. According to the granularity of the shared resources,this strategy can be divided into the resource sharing strategy for logic link protection and that for wavelength link protection. Simulation is implemented on the topology of the European research and academic network GEANT. The results show that compared with the dedicated protection unicast routing mechanism,the proposed routing mechanism can effectively solve the survivability problem in the optical network with low er blocking rate and higher load balancing degree.