增强虚拟网络坐标系统准确性的时延预处理技术

摘要

在实际网络中网络时延不断抖动甚至出现长拖尾现象,不仅会导致节点坐标振荡,还严重影响虚拟网络坐标系统的稳定性及时延预测的准确性,因此必须对实测时延进行预处理以避免“失真时延”影响虚拟网络坐标系统的性能.介绍并分析了已有的时延预处理算法△-filter和MP-filter的性能特点,提出了RPE-filter时延过滤算法,实验对比表明RPE-filter算法不仅能够过滤遭受随机延迟污染的时延,还能平滑时延曲线的波动,更能实时反映网络拓朴的变化,且绝对误差累加和明显小于△-filter和MP-filter.%In the actual network,network delay jitter even with a long tail,not only causes coordinates oscillation,but also seriously affects the stability of IP network coordinate system and accuracy of time delay prediction,so it is necessary to preprocess the measured time delay to avoid the performance of IP network coordinate system affected by "distortion delay".This paper introduces and analyses the characteristics of the existing delay preprocessing algorithms of △-filter and MP-filter,then puts forward another delay filter algorithm called RPE-filter.Comparing experiment shows that RPE-filter can not only filter the time delay polluted by random delay,but also can smooth fluctuation of the delay curve,even more can real-time reflect the changes of network topology,and the most important is that its absolute error accumulation is obviously less than △-filter and MP-filter.