Packet-dispersion techniques and a capacity-estimation methodology
Packet-dispersion techniques and a capacity-estimation methodology
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DOI：
10.1109/tnet.2004.838606
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发表时间：
2004-12
期刊：
影响因子：
--
通讯作者：
C. Dovrolis;P. Ramanathan;David Moore
中科院分区：
文献类型：
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作者：
C. Dovrolis;P. Ramanathan;David Moore
该数据包技术旨在通过分散两个相等大小的探测数据包的分散，估算路径（瓶颈带宽）的容量。也有人认为，更长的数据包爆发（数据包列车）的分散可以估计路径的可用带宽。本文研究了这些数据包对和数据包训练分散技术的深度。我们首先证明，通常，数据包对带宽测量值遵循多模式分布，并解释了多种局部模式的原因。路径容量是局部模式，通常与此分布的全局模式不同。我们说明了网络负载，交叉流量数据包大小的可变性以及探测数据包大小对数据包对带宽分布的影响。然后，我们切换到长包装列车的分散体。数据包训练分散分布的平均值对应于我们称为平均分散率（ADR）的带宽度量。我们证明ADR是路径可用带宽的容量和上限的下限。将所有部件整合在一起，我们提出了一种能力估计方法，该方法已在称为Pathrate的工具中实现。在过去三年中测量了数百种互联网路径后，我们报告了我们在病率的经验。
The packet-pair technique aims to estimate the capacity of a path (bottleneck bandwidth) from the dispersion of two equal-sized probing packets sent back to back. It has been also argued that the dispersion of longer packet bursts (packet trains) can estimate the available bandwidth of a path. This paper examines such packet-pair and packet-train dispersion techniques in depth. We first demonstrate that, in general, packet-pair bandwidth measurements follow a multimodal distribution and explain the causes of multiple local modes. The path capacity is a local mode, often different than the global mode of this distribution. We illustrate the effects of network load, cross-traffic packet-size variability, and probing packet size on the bandwidth distribution of packet pairs. We then switch to the dispersion of long packet trains. The mean of the packet-train dispersion distribution corresponds to a bandwidth metric that we refer to as average dispersion rate (ADR). We show that the ADR is a lower bound of the capacity and an upper bound of the available bandwidth of a path. Putting all of the pieces together, we present a capacity-estimation methodology that has been implemented in a tool called pathrate. We report on our experiences with pathrate after having measured hundreds of Internet paths over the last three years.