Transmission Control Protocol (TCP) provides reliable, connection oriented, end to end communication. TCP is used mostly by wired links. Source of delay and data corruption, due to peripheral parameters, is minimal in wired links. Thus packet loss due to congestion is the main concern. Therefore quality of service parameters, namely throughput, delay and packet loss need to be analyzed. At present many TCP variants are available and therefore their performance can be compared based on these parameters. In this paper various TCP variants are simulated and their performance is compared in terms of throughput, delay, packet delivery ratio and packet loss for a particular network topology. NS2, an event driven simulator, is used for simulation. The result shows that TCP Vegas is better than other TCP variants for sending data and information.