What functions does the transport layer perform in the OSI or TCP/IP model?

The transport layer in the OSI and TCP/IP models is responsible for data transfer between network nodes, ensuring reliability and flow control. Main functions:

• Connection management: establishing, maintaining, and terminating connections between sender and receiver.
• Reliable data transfer: error detection and correction, retransmission of lost packets.
• Flow control: regulating the data transmission rate to prevent overwhelming the receiver.
• Segmentation and reassembly: breaking large messages into segments and reassembling them at the receiving end.
• Multiplexing: supporting multiple logical connections over a single physical channel.

In TCP/IP, the transport layer is represented by the TCP (reliable, connection-oriented) and UDP (fast, connectionless) protocols.