User Datagram Protocol (UDP)
Like IP, UDP is connectionless and unreliable protocol. It doesn’t require making a connection with the host to exchange data. Since UDP is unreliable protocol, there is no mechanism for ensuring that data sent is received.
UDP transmits the data in form of a datagram. The UDP datagram consists of five parts as shown in the following diagram:
Points to remember:
UDP is used by the application that typically transmits a small amount of data at one time.
UDP provides protocol port used i.e. UDP message contains both source and destination port number, that makes it possible for UDP software at the destination to deliver the message to correct application program.