I. INTRODUCTION
This overview enlightens different TCP versions algorithm like TCP Tahoe, Reno, New Reno, SACK, FACK and Vegas, on the basis of fundamental functions such as slow start, congestion avoidance, fast retransmission and fast recovery. Current TCP achievements contain several algorithms designed to run network congestion while maintaining throughput. The authors [1] argued and compared the performance of TCP Reno and TCP Vegas. This paper emphasize that due to the use of round trip times measurement, window dynamics of TCP Vegas are much more stable than those of TCP Reno, resulting in more efficient utilization of the network recourses. TCP Reno discriminates against users with long propagation delays; whereas TCP Vegas fairly shares the available bandwidth between users, whatever their propagation delays are. A paper [2] explains the congestion control algorithm in simulated implementation of SACK TCP and shows that the selective acknowledgments are not required to solve Reno TCP's performance problems when multiple packets are dropped. The absence of selective acknowledgement does impose limits to TCP's ultimate performance. In particular, the paper shows that without selective acknowledgments, TCP implementations are constrained to either retransmit at most one dropped packet per round trip time, or to retransmit packets that might have already been successfully delivered. Forward Acknowledgment (FACK) congestion control algorithm developed [3], addresses many performance problems in the internet. FACK is designed on the basis of first principle of congestion control and TCP SACK option. It achieves more exact control over the data flow in the network when the congestion is decoupled from other algorithms like data recovery. In this paper two algorithms are designed to develop the performance in the exact state. Simulation is used for the comparison of FACK with Reno and Reno with SACK. Finally, it proves the impact on the potential performance of FACK in the internet.