UDP / User Datagram Protocol
The User Datagram Protocol (UDP), defined by IETF RFC768 (http://www.ietf.org/rfc/rfc0768.txt), is one of the core members of the Internet protocol suite and provides a simple, but unreliable message service for transaction-oriented services. Each UDP header carries both a source port identifier and destination port identifier, allowing high-level protocols to target specific applications and services among hosts.