DWDM网状网中的路径保护算法

为满足在网络生存性要求的同时提高网络资源的利用率,提出一种区分服务路径保护算法。在基于GMPLS(Generalized Mu lti-Protocol Label Sw itch ing)的DWDM(Dense W avelength D ivision Mu ltip lexing)网络中,当网络节点不具备波长变换能力且只配备有限对光收发器时,该算法针对网络中的高可靠性业务、中等可靠性业务及可抢占式业务对可靠性的不同要求,为其选择不同的保护方案。仿真结果表明:在3种类型业务等概率出现的情况下,可抢占式业务的平均阻塞率增加幅度最小,使带宽碎片造成的资源浪费减少了50%;高可靠性业务的共享程度比,随着连接请求的增加而降低;当网络达到动态平衡时,网络中各链路的总保护通路带宽与总工作通路带宽之比,在0.8~1之间;可抢占式业务所占带宽中属于保护通路的带宽与可抢占式业务所占带宽之比,随着网络负载的增大而增加缓慢。因此该算法在保证业务服务质量要求的同时达到了充分利用网络资源、平衡网络负载的目的。

Path Protection Algorithm in DWDM Mesh Networks

In order to satisfy the demand for the survivability of a network,and improve t he utilization ratio of the network resource,proposed a kind of differentiated services path protection algorithm.In a DWDM(Dense Wavelength Division Multiple xing) mesh network based on GMPLS(Generalized Multi-Protocol Label Switching),network nodes are incapable of wavelength transform,and there are finite pairs of ray-transceiver,the algorithm was to adopt different path protection scheme s for the high reliability service,the middle reliability service and the preem pt one.The simulation results indicated that under the status of three types of services appearing equiprobablly,the increasing scope of the mean blocking rat e of the preempt service was the least,and the resource waste resulted from ban dwidth fragments decreased 50%;The shared extent rate of the high reliability s ervice decreased with the increase of the connection requests,when the network was in dynamic balance,the ratio of protecting path bandwidth to working path b andwidth of the links in the network was between 0.8 and 1;the rate of the ban dwidth using protecting path to the occupying bandwidth of the preempt service i ncreased slowly with the increase of network loads.So the new algorithm made th e network resource to be used greatly and balanced the loads of a network while guaranteeing the quality of services.