Transport Layer

Between the Internet layer and Application layer of the TCP/IP architecture model is the Transport Layer. This layer has two primary protocols, the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP). TCP is a connection based protocol that provides error detection and correction with reliable delivery of data packets. UDP is a connectionless protocol with low overhead. When writing application software a developer normally chooses TCP or UDP based on whether it is more important to have a reliable connections with bi-directional communication and error management, or if it is more important to develop a low overhead, streamlined application.