流量管理中队列调度算法研究

Research on Queue Scheduling Algorithm of Traffic Management

介绍了包交换芯片流量管理中队列调度的算法,分析DWRR(Deficit Weighted Round-Robin)算法的优缺点,并提出了一种基于DWRR改进的调度算法。该算法能够根据网络中实时的数据包帧长,来调节每次轮询中向各个队列添加的信用度,能够减少各个队列的时延,同时又增强带宽分配的相对公平性,改善了DWRR算法不能很好满足业务的时延特性。使用NS-2仿真器来对改进的算法进行网络仿真,最终的仿真结果表明改进后的DWRR算法能够有效地降低时延,可以在一定程度上提高QoS。

In this paper, the queue scheduling algorithm of traffic management in packet switching chip is presented and the advantages and disadvantages of Deficit Weighted Round-Robin（DWRR） queue scheduling algorithm are analyzed. Meanwhile, an improved scheduling algorithm based on DWRR is also introduced, which is based on real-time network packet frame length to regulate the credit adding to the queue in each Round-Robin, efficiently reduce the delay of each queue and enhance the relative fairness of bandwidth allocation, improving the weakness of DWRR algorithm that can not meet service delay perfectly. The improved algorithm uses NS-2 simulator to network emulation. Finally, the simulation results show that the improved DWRR algorithm can effectively reduce the delay and, to some extent, the QoS can be increased.