Transport Layer

The Transport Layer contains the TCP and UDP protocols.

With EZ Stack Configurator, you select which protocols to include in your project: UDP or TCP or both.

The Transmission Control Protocol (TCP) guarantees packet delivery. TELNET, HTTP and FTP are TCP applications. TCP provides full transport layer services to applications. TCP is a reliable, connection-oriented protocol. After a connection is established at both ends of a transmission, TCP divides a stream of data into smaller units called segments at the sending end. Segments are carried across the internet inside of IP datagrams. At the receiving end, TCP collects each datagram and reconstructs the data stream.

The User Datagram Protocol (UDP) does not guarantee packet delivery. TFTP and DHCP are UDP applications. UDP provides a connectionless and mostly reliable service to applications. Since there is no connection established and each user datagram sent by UDP is independent, each UDP request must be small enough to fit into one user datagram. UDP hands off the message received to the process listening on the destination port number specified in the user datagram. UDP is suitable for a process with internal flow and error control mechanisms like TFTP. Also, it is suitable for a process that requires simple request-response communications without concerns for flow and error control.