This paper is aimed to discuss congestion control and review TCP functionality that provides congestion control techniques for handling buffer –overflows, loss of packets and congestions that we experience over a network. The primary focus is on discussing the four intertwined algorithms, namely slow start, congestion avoidance, fast retransmit, and fast recovery, which will help us to solve this congestion problem. The algorithms are rooted in the idea of achieving network stability. We demonstrate in this paper how the implementation of this algorithm reduces congestion over the congested network and more importantly how it scales gracefully in the network environment by providing high utilization and low queuing delays.