What is the key role of transport layer protocols like TCP?

Transport layer protocols, such as TCP (Transmission Control Protocol), are critical in networking for establishing reliable end-to-end communication between devices. The primary function of TCP is to ensure that data is transmitted accurately and in the correct sequence from the sender to the receiver. This is achieved by implementing error checking, retransmission of lost packets, and flow control, which prevents overwhelming the receiver with too much data at once.

TCP also establishes a connection-oriented communication model, meaning that a connection is first established before data is exchanged. This connection setup phase helps ensure that both the sender and receiver are ready to communicate, thus facilitating reliable transmission.

The importance of establishing reliable communication is underscored in scenarios where data integrity and order are crucial, such as file transfers, web page loading, and video streaming. Transport layer protocols, therefore, play an essential role in ensuring that users experience seamless and accurate data transmission across the network.