输入排队iSLIP算法的改进与比较

Improvement and comparison of input queue iSLIP algorithm

高速路由器交换网络中,输入排队调度算法有良好的性能。为了进一步提高经典算法iSLIP的性能,根据虚拟输出队列(VOQ)中包的个数和队首包的等待时间不同,对iSLIP算法进行改进,提出了lp-iSLIP(Long Queues Prioriy iSLIP)算法和op-iSLIP(Old Queues Priority iSLIP)算法。通过仿真可以看到改进后两种算法包的延时较iSLIP算法有一定降低,即算法性能有了提高。最后对iSLIP算法和对信元加入优先级的pri-iSLIP算法进行比较,仿真结果显示pri-iSLIP算法的性能较好。

In high speed routers switching fabric, input- queued scheduling algorithms have favorable performances. In order to improve the performances of the well - known algorithm iSLIP, iSLIP algorithm is improved basing on the differences of the length of virtual output queues （VOQ） or the waiting time of the queue first cells, putting forward the new algorithms called lp-iSLIP and op-iSLIP. The mean cell latency in the two improved algorithms is shortter compared with iSLIP algorithm, .so their performances are better. Last we have compared iSLIP algorithm and pri-iSLIP algorithm, the simulation results show the performances of pri-iSLIP algorithm is better than iSLIP algorithm.