一种端到端的有效带宽测量方法

摘要

有效带宽测量在服务器选择、覆盖网络路由选择和网络流量工程等方面有广泛的应用.通过分析发送频率与单向延时之间的关系,提出了一种基于多项式拟合的有效带宽测量方法PFAB(Polynomial Fitting for Available Bandwidth).PFAB通过发送探测速率逐渐下降的探测包,并检测OWD的变化,推断探测速率和有效带宽之间的关系.当探测速率大于有效带宽时,OWD持续增长;在探测速率等于有效带宽时,OWD达到最大值,之后开始下降.NS-2仿真实验结果表明该方法能有效减少探测包数量,缩短探测时间,并且对网络造成的干扰小;在探测包瞬时频率变化较大时,可以快速到极值点,减少测量误差.%The available bandwidth measurement is important for many Internet applications, such as server selection, overlay network routing, and traffic engineering. This paper analyzes the relationship of the probing rate and the one-way delays. Then based on this,a methodology which call PFAB(polynomial fitting for available bandwidth) in the basic idea from polynomial fitting is presented to measure end-to-end available bandwidth.In PFAB, the change of the one-way delay happen according to one-way delay trends to infer the relationship between the probing rate and the available bandwidth. If one-way delay is increasing,the probing rate is larger than the present available bandwidth;if one-way delay is not increasing,the probing rate is equals the present available bandwidth; otherwise,one-way delay is decreasing. This methodology can reduce the number of probe bytes,the time of probing and network interference through NS-2 simulations. It also can find out extreme point with lowing measurement errors when probing rate has a big change.