Performance of High-Speed TCP Applications in Networks With Very Small Buffers

In the on-going debate on how large Internet router buffers should be, of particular interest is a recent claim that 10-50 packets of buffering suffice, permitting all-optical buffering in the Internet core. It is argued that TCP traffic, when well-paced (typically by slow access links), can achieve acceptable link utilisation with very small buffers. In this paper, the authors investigate if this result holds in the presence of highperformance scientific applications connecting over high-speed access links. Their results show that the presence of a significant proportion of high-speed access links necessitates larger buffers at the core link. However, they show that end-host TCP pacing by such applications can alleviate the problem effectively.