Transmission Control Protocol (TCP) is a communications standard that enables application programs and computing devices to exchange messages over a network. Since the 1970s, several TCP variants have been introduced to deal with the fast increasing network capacities, especially in high Bandwidth Delay Product (high-BDP) networks. The significance of this protocol stems from its numerous congestion management mechanisms, which manipulate TCP sending rates and force TCP to respond to congestion alerts. This is a transport layer protocol that interacts with the Internet Protocol (IP), which defines how devices send data packets to one another. The paper makes a comparative analysis of TCP variants like TCP Tahoe, TCP Reno, TCP New Reno, TCP Vegas and TCP Sack over different routing protocols like AODV, DSDV and DSR, considering factors such as Packet Delivery Ratio (PDR), Delay (milliseconds), and Throughput (Megabits per second), while the mobile nodes are in motion (considering different speeds) using the Network Simulation (NS-2) software.