一种优化指针策略的输入排队调度算法

Pointer Strategy Optimized Scheduling Algorithm for Input Queued Switches

针对FIRM(fcfs in round-robin matching)算法在处理非均匀业务时,延时和丢包性能出现缺陷的问题,在FIRM算法的基础上设计并实现了一种优化指针策略的low-FIRM(longest oldest weighted FIRM)算法。该算法根据队列长度和队首信元等待时间的权值修改输入端口的轮询指针,使得权值大的队列趋于优先服务,从而优化了在非均匀业务下的调度性能。接着给出了low-FIRM算法的性能分析和仿真,与iSLIP(iterative round-robin matching with slip)算法、FIRM算法进行了比较。仿真结果表明,low-FIRM与经典算法相比,在均匀业务下的性能近似,而在非均匀业务下性能有了较大的提升。

To resolve the performance decrease of FIRM under non-uniform traffic, a pointer strategy optimized algorithm named low-FIRM is proposed. This scheduling algorithm modifies round-robin pointers of each input queue according to the weight of the length and waited time of each virtual output queue, which makes the queue with largest weight tend to be served In＇st. Low-FIRM is described and its performance is compared with those of iSLIP and FIRM. Simulation results show that low-FIRM achieves high performance under both of the uniform and non-uniform traffic.