WPathload:一种改进的可用带宽测量方法

WPathload:A Modified Available Bandwidth Measurement Algorithm

可用带宽是网络的重要资源,对其准确的估计与测量是流量工程和网络监测等必须解决的问题,但对它的实际测量存在许多困难.针对Pathload可用带宽测量方法存在收敛慢、开销大的问题,提出了一种Pathload可用带宽测量的改进方法(WPathload).该方法基于时延变化的统计规律,改进发送速率调整算法,并采用周期流组到达目的端的速率代替周期流的发送速率,更新可用带宽上界,从而加快收敛速度,降低测量开销.实验结果表明,改进后的方法能快速反映可用带宽的变化,增强了跟踪带宽变化的能力.

Available user perceived perfo traffic engineering, bandwidth, as one of the most crucial network resources, directly influences the rmance, and its accurate measurement and estimation is an essential problem in network monitoring and design of transport protocols. Several tools have, consequently, been proposed to measure end-to-end available bandwidth. Among these tools, Pathload is one of the important methods for measuring available bandwidth. Unfortunately it still has some problems, e.g. the long convergence time and large probe traffic. To solve the problems, WPahtload, a modified available bandwidth measurement algorithm based on delay jitter trend is proposed. In WPahtload, the delay jitter is designed, which can indicate the relationship between the probing rate and the end-to-end available bandwidth. By cSlculating these parameters, the end system can adjust the transmission rate quickly. Furthermore, the fleet sending rate is used to replace by arrival rate, and then refresh the upper limit of available bandwidth, so that the available bandwidth can be estimated quickly as well as not resulting in large influence on existing traffic. The simulation experiments show that the proposed algorithm WPathload could measure end-to-end path available bandwidth with less overhead and faster convergence rate than that of Pathload. Furthermore, the proposed algorithm tends to be capable of rapidly reflecting changes of bandwidth, thus improving the capability of tracing bandwidth changes.