A mobile ad hoc network (MANET) is generally defined as a network that has many free or autonomous nodes, often composed of mobile devices or other mobile pieces that can arrange themselves in various ways and operate without strict top-down network administration. In MANET each node acts as a router and these networks are scalable. To support connectivity between nodes MANET networks use different kinds of protocols such as AODV, DSR, and DSDV etc. MANETs is an IEEE 802.11 framework. It is an interconnected collection of wireless nodes where there is no networking infrastructure in the form of base stations, devices do not need to be within each other‘s communication range to communicate, the end- users devices also act as routers, nodes can enter and leave over time, data packets are forwarded by intermediate nodes to their final destination. The purpose of this paper is to analyze and compare the different TCP variants namely Reno, New Reno, Vegas under the routing protocol i.e. DSDV (Destination Sequenced Distance Vector).