TCP NewVegas: Providing Good TCP Performance in both Homogeneous and Heterogeneous Environments

Its more refined congestion control mechanisms, based on the estimation of the round trip delays, allow TCP Vegas to outperform the more widespread TCP Reno congestion control, based only on the packet loss detection, in a number of network environments. However, these mechanisms make TCP Vegas less aggressive with respect to TCP Reno; thereby TCP Vegas sources show high weakness in taking the available bandwidth when competing with TCP Reno sources. This is a major reason that hinders the spread of TCP Vegas among Internet users. This paper proposes a new adaptive mechanism for TCP Vegas, called TCP NewVegas, in order to improve its behavior even in heterogeneous network scenarios. The simulations show that TCP NewVegas guarantees good performance even in mixed network environments, without canceling the desirable features (e.g. fairness) that TCP Vegas exhibits in homogeneous environments.