Pathload: a Measurement Tool for End-to-end Available Bandwidth

The available bandwidth of a network path P is the maximum throughput that P can provide to a ow, without reducing the throughput of the cross tra c in P . We have developed an endto-end active measurement tool, called pathload, that estimates the available bandwidth of a network path. The basic idea in pathload is that the one-way delays of a periodic packet stream show increasing trend, when the stream rate is larger than the available bandwidth. In this paper, we describe pathload in detail, and show some experimental results that illustrate the tool's accuracy.