In data networks, what is the role of the Transport layer?

The Transport layer's primary function is to manage end-to-end communication between devices in a network, which is crucial for ensuring that data is reliably delivered and in the correct order. This layer is responsible for segmenting data from the application layer and ensuring that it reaches the correct destination. It provides services such as flow control, error control, and retransmission of lost packets, which all contribute to the integrity and reliability of the data transmission.

When data is exchanged over a network, variations in network conditions can cause packets to arrive out of order or get lost. The Transport layer addresses these issues by reordering packets, handling retransmissions if packets are lost, and providing acknowledgments to confirm successful delivery. Protocols like TCP (Transmission Control Protocol) exemplify these functions, offering reliable, connection-oriented communication, whereas UDP (User Datagram Protocol) offers a simpler, connectionless service that is less reliable but has lower latency.

Thus, managing end-to-end communication is essential at this layer, making it the correct choice for describing the primary role of the Transport layer in data networks.