TCP Vegas was introduced in 1994  as an alternative to TCP Reno. Unlike Reno (or its variants such as NewReno and SACK), that uses packet loss as a measure of congestion, Vegas uses queueing delay as a measure of congestion [15, 18]. Vegas introduces a new congestion avoidance mechanism that corrects the oscillatory behavior of AIMD (Additive Increase Multiplicative Decrease). While the AIMD algorithm induces loss to learn the available network capacity, a Vegas source adjusts its sending rate to keep a small number of packets buffered in the routers along the path. Provided there is enough buffering, a network of Vegas sources will stabilize around a proportionally fair equilibrium and packet loss will be eliminated; see  for details. In this paper, we study the stability of this equilibrium in the presence of network delay, motivated by two lines of recent research.
© 2005 Springer-Verlag Berlin Heidelberg. First Online: 13 November 2004. We are grateful to John Doyle, Fernando Paganini, Jiantao Wang, Zhikui Wang, for helpful discussions. We acknowledge the support of Korean Government through BK21 Project, NSF through grant ANI-0113425.