Study of a non-intrusive method for measuring the end-to-end capacity and useful bandwidth of a path

Studies and tools development for applications sensitive to data rates is a very active research field. Tools for measuring the end-to-end performance of a link between two hosts are very important for distributed application performance optimization. Bandwidth evaluation methods aim to provide a realistic view of the raw capacity but also of the dynamic behaviour of the interconnection that may be very useful to evaluate the time of bulk data transfer. Existing methods differs according to the measurements strategies and the evaluated metric. This paper analyses the available bandwidth measurements and the total capacity measurements approaches. None of the proposed tools permit to evaluate both metrics while giving an overview of the link topology. An approach using a hop-by-hop packet pair method and a fine analysis of the measurements can provide such informations. The principles of this hop-by-hop measurement of the capacity and available bandwidth method are exposed in this paper. This proposition has been validated in simulation, then implemented in Linux and validated experimentally. We compared our method with the others to define its limits and the potential utilisations on the developed tool.