UDP (User Datagram Protocol)

A connectionless protocol within TCP/IP that corresponds to the transport layer in the International Standard Organization's Open System Interconnect (ISO/OSI) reference model. UDP converts data messages generated by an application into packets to be sent through IP, but it is unreliable because it does not establish a path between sender and receiver before transmitting and does not verify that messages have been delivered correctly. UDP is more efficient than TCP, so it is used for various purposes, including Simple Network Management Protocol (SNMP). The reliability depends on the application that generates the message. [Exchange 2007]

The User Datagram Protocol (UDP) is a set of rules that allow communication between two processes across a network. The protocol is unreliable, which means that information is not guaranteed to be transferred correctly between the two processes. See Transmission Control Protocol (TCP) for an alternative reliable protocol.