What does udp mean?

The Internet Protocol Suite supports a connectionless transport protocol called User Datagram Protocol (UDP). UDP provides an application with a way to send encapsulated IP packets without establishing a connection. RFC 768 describes UDP.

The transport layer of the Internet has two main protocols, which complement each other. Connectionless is UDP, which does almost nothing but send packets to applications and allow them to build their own protocols at the required level. What is connection orientation? Almost omnipotent TCP.

Features:

UDP provides connectionless communication, which does not guarantee the reliability of data packets, and is suitable for transmitting a small amount of data at a time. The application layer is responsible for the reliability of UDP transmission. Commonly used UDP port numbers are: 53(DNS), 69(TFTP), 16 1(SNMP), and the UDP protocols used are: TFTP, SNMP, NFS, DNS and BOOTP.

UDP message has no reliability guarantee, sequence guarantee and flow control fields, so its reliability is poor. However, it is precisely because UDP protocol has few control options, small delay and high data transmission efficiency in the process of data transmission that it is suitable for applications that do not require high reliability, or applications that can ensure reliability, such as DNS, TFTP, SNMP and so on.