Buffer sizing for elastic traffic

Two areas of active research are likely to have a major impact on the future performance of the Internet. These are firstly, the evaluation of the buffer size required to ensure fair, stable and efficient sharing of link bandwidth and secondly, the proposition of new congestion control algorithms, more suitable for increasingly high link speeds than the current version of TCP. In this paper, we re-examine propositions for a drastic reduction in buffer size in the light of our understanding of the nature of Internet traffic at flow level. We demonstrate through simulation that the trade-off between throughput and delay is not as favourable as previously predicted. We also illustrate the significant gains in this context that would accrue from the implementation of per-flow fair scheduling in router queues