Abbreviated UDP. The connectionless, transport-level protocol used in the TCP/IP suite of protocols, usually bundled with IP-layer software. Because UDP does not add overhead, as does connection-oriented TCP, UDP is often used with SNMP (Simple Network Management Protocol) applications.
Multicast applications, such as Mbone and the Real-time Transport Protocol, that deliver audio and video streams use UDP as their delivery mechanism because the acknowledgment and retransmission services offered by TCP are not needed and add too much overhead. If a packet of audio data is lost, retransmission is neither practical nor desirable.
See also multicast backbone; Real-time Transport Protocol; Transmission Control Protocol.