Understanding UDP Protocol in Network Transport Layer

This presentation explains the UDP (User Datagram Protocol) in the context of the transport layer of computer networks. The pedagogical approach moves from the upper layers to the lower layers of the network model. The transport layer's function is to route data to the correct program on the correct computer, using IP addresses to identify machines and ports to identify applications. UDP, defined in RFC 768 in 1980, represents the simplest method to accomplish this task. The UDP header contains four essential elements: the source port, the destination port, the data length, and a checksum to verify data integrity. Standard ports include port 80 for HTTP and 443 for HTTPS. UDP is described as unreliable because it does not guarantee packet delivery, their order of arrival, or their retransmission in case of loss. These responsibilities fall to the application. For reliable communications, the TCP (Transmission Control Protocol) protocol is preferred.