RED分组丢弃算法性能研究

Performance of Random Early Detection Packet Discard Scheme in ATM Switches

本文研究了在ATM交换机上实现的RED算法的性能 .在固定有效带宽、时变有效带宽情况下和同种、异种业务环境下 ,研究了RED算法的通过率、公平性和时延等性能 .经研究表明 :RED算法有必要与EPD算法相结合 ,构成RED +EPD算法 .采用RED +EPD算法的ATM交换机通过控制平均排队长度 ,有效地减小了交换机的平均排队时延 .通过与其他分组丢弃算法进行性能比较表明 :采用RED +EPD算法的ATM交换机 ,可提供比EPD算法略高的通过率 ,更好的公平性和更低的排队时延 ,能较好地支持具有时延要求的业务 .

In this paper,we study the performance of RED (Random Early Detection) algorithm implemented in ATM switches.The throughput,fairness and delay of RED algorithm are studied in the environment of homogeneous and heterogeneous traffic and in the environment of time varying available bandwidth.It show that RED algorithm,which should be integrated with EPD algorithm,reduces the average queuing delay through effectively controlling the average queue length.Through performance comparison with other packet discard schemes,the ATM switch with RED+EPD algorithm can provide higher throughput,better fairness and smaller delay than the switch with EPD algorithm,so it can support the traffic with delay requirement.