Prediction of short-lived TCP transfer latency on bandwidth asymmetric links

Abstract

TCP over bandwidth asymmetric networks such as Cable TV and Asymmetric Digital Subscriber Loop (ADSL) exhibits different characteristics from TCP on symmetric links. A number of techniques have been proposed to address this problem. However, previous research has been largely focused on bulk transfers. This paper investigates the effects of bandwidth asymmetry on Web-like short-lived transfers. Two prediction models, one given in a closed form and the other in a recursive form, are presented for TCP transfers without and with ACK Filtering (AF), a representative optimizing technique for TCP transfers over bandwidth asymmetric links. Ns-2 based experiments show that these models can predict TCP transfer latency with a high degree of accuracy.