User Datagram Protocol (UDP) (
RFC 768) is another main protocol
of the IP suite, and is an alternative to TCP. UDP is stateless
and connectionless in that there is no handshake to set up a session,
and no connection between the sender and receiver; the packets may
take different routes to get to a single destination. UDP is considered
an unreliable protocol because it does not provide acknowledgments,
error-checking, retransmission, or reordering of datagrams. Without
the overhead required to provide those features, UDP has reduced
latency and is faster than TCP. UDP is referred to as a best-effort
protocol because there is no mechanism or guarantee to ensure that
the data will arrive at its destination.