A conceptual exploration of TCP variants

TCP- Transmission Control Protocol is a connection oriented and reliable transport layer protocol of TCP/IP protocol suite. TCP provides process-to-process, stream and full duplex communication. TCP also provides flow, error and congestion control. Congestion is the traffic jam of the packets in the network. Congestion occurs when the load (number of outstanding packets) in the network is higher than of its capacity to handle. This paper explains basic congestion control mechanisms used by TCP. Many TCP variants have been proposed to improve TCP congestion control mechanisms. This paper explores some of the most widely used TCP variants conceptually. This paper also discusses some of the possibilities of future research work in TCP congestion control.