Techniques for available bandwidth measurements in IP networks: a performance comparison

As the Internet grows in scale and complexity, the need for accurate traffic measurement increases. Among the different parameters relevant to traffic measurement, the paper pays attention to the available bandwidth of a path. In particular, a performance comparison of three different techniques, devoted to available bandwidth measurement, is attained under different operating conditions. The comparison is based on the outcomes of an extensive experimental activity. Experimental tests are not limited to the mere execution of the software tools that implement the techniques under test; indeed, a proper measurement station comprising a digital counter has been set up by the authors with the aim of gaining a reference value to be compared with results provided by the considered tools. The adoption of a performance evaluation methodology relying on the use of electronic instrumentation for time measurement represents a good example of crossfertilization between two distinct research areas: networking on one side and electronic measurements on the other. The tools have been tested under different cross-traffic conditions and their performance has been evaluated in terms of the following metrics: concurrence, repeatability, bias, and time. For each cross-traffic scenario and with reference to every performance metric, the paper identifies the tool that provides the best results. Furthermore, an optimal setting for the parameters of each tool has been identified thanks to the extensive experimental activity that has been performed.