A Game-Theoretic Analysis of TCP Vegas

We use the tools from game theory to understand the impacts of the inherent congestion pricing schemes in TCP Vegas as well as the problems of parameter setting of TCP Vegas on its performance. It is shown how these inherent pricing schemes result in a rate control equilibrium state that is a Nash equilibrium which is also a global optimum of the all-Vegas networks. On the other hand, if the TCP Vegas’ users are assumed to be selfish in terms of setting their desired number of backlogged packets in the buffers along their paths, then the network as a whole, in certain circumstances, would operate very inefficiently. This poses a serious threat to the possible deployment of Vegas-based TCP (such as FAST TCP) in the future Internet.