Nettimer: A Tool for Measuring Bottleneck Link Bandwidth

Measuring the bottleneck link bandwidth along a path is important for understanding the performance of many Internet applications. Existing tools to measure bottleneck bandwidth are relatively slow, can only measure bandwidth in one direction, and/or actively send probe packets. We present the nettimer bottleneck link bandwidth measurement tool, the libdpcap distributed packet capture library, and experiments quantifying their utility. We test nettimer across a variety of bottleneck network technologies ranging from 19.2Kb/s to 100Mb/s, wired and wireless, symmetric and asymmetric bandwidth, across local area and crosscountry paths, while using both one and two packet capture hosts. In most cases, nettimer has an error of less than 10%, but at worst has an error of 40%, even on cross-country paths of 17 or more hops. It converges within 10KB of the first large packet arrival while consuming less than 7% of the network traffic being measured.

• Type: Conference
• Year: 2001
• Where: USITS
• Authors: Kevin Lai, Mary Baker
• Keywords: Bottleneck Bandwidth, Bottleneck Link Bandwidth, Operating System, Packet Capture, USITS 2001