Is TCP bidirectional or full-duplex?

Question

Bidirectional and full-duplex are different concepts. For example the Ethernet is only half-duplex because at a specific time, only on

Answer 1

Yes, a TCP connection provides a full-duplex service. Let's understand the meaning of full-duplex. It means exchanging data(sending and receiving) between two entities at the same time. As TCP is a transport layer protocol and transport layer protocols provide logical communication between processes running on different hosts, here also the meaning of full duplex is in this respect.

Here full-duplex means "If there is a TCP connection between Process A on one host and Process B on another host, then application layer data can flow from Process A to Process B at the same time as application layer data flows from Process B to Process A". A TCP connection is also always point-to-point, that is, between a single sender and a single receiver. Remember, the data from Process A is yet to pass through layers below transport layer, similarly the data from Process B will pass through layers below transport layer.

Source: Computer Networking by Kurose, Ross.