Parameter Setting Games in TCP Vegas and FAST TCP

This paper is concerned with the parameter setting problems of some delaybased versions of TCP (TCP Vegas and the recently developed Vegas-based FAST TCP) from a game-theoretic point of view. It is shown that 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. Our analysis also points out that FAST TCP faces the same parameter setting problem as with TCP Vegas, and as a result, it is very vulnerable to selfish actions of the users. This poses a serious threat to the possible deployment of FAST TCP in the future Internet.