A multiple time-scale model for TCP bandwidth sharing under user heterogeneity

Abstract

Building on the vast body of existing TCP models, we develop a novel versatile model that explicitly captures user heterogeneity, and takes into consideration dynamics at both the packet level and the flow level. It is described how the resulting multiple time-scale model can be numerically evaluated. Validation is done by using NS2 simulations as a benchmark. In extensive numerical experiments, we study the impact of heterogeneity in the round-trip times on user-level characteristics such as throughputs and flow transmission times, thus quantifying the resulting bias. In particular, we investigate to what extent this bias is affected by the networks' 'packet-level parameters', such as buffer sizes. We conclude by extending the single-link model in a straightforward way to the general network setting. © IFIP International Federation for Information Processing 2005.