一种基于速率和队列长度的主动队列管理机制

A Rate and Queue Controlled Active Queue Management

本文研究了拥塞产生的原因及其表现形式 ,提出了一种基于报文到达速率和队列长度的随机早丢弃算法 (RQ) .根据拥塞的严重程度和变化趋势将拥塞划分为六个级别 ,每个级别采用合适的丢弃概率 ,从而将队列控制在理想工作点附近 .利用经典控制理论 ,分析了系统的稳定性 ,给出了参数配置的原则 .最后 ,用NS网络仿真器对算法性能进行了验证 .

Active Queue Management is an active research area.Its main objective is to provide low delay and low loss service in packet-switched network.RQ is a new random early detection algorithm.It can divide the seriousness of congestion into six levels according to the aggregate packet arrival rate and the average queue length in the router.Each level has appropriate packet drop probability.The responsiveness and stability properties of RQ are superior to RED in favor of promptly reacting of rate-based dropping than queue-based.TCP and RQ are modeled as a closed loop feedback control system and the stability is analyzed.The performance of RQ was compared with RED by simulations.The results show that RQ can keep low queuing delay and low packet loss in wide variable load conditions.