Without establishing a connection before transmitting data, after receiving the UDP packets do not need to give any confirmation.
Unreliable, connectionless, low delay, suitable for small files.
UDP only adds very little functionality on top of IP datagram service, that is, multiplexing and demultiplexing error detection function.
The main features of UDP:
1.UDP is no connection , reducing overhead and latency before data transmission.
2.UDP maximum effort delivery, that does not guarantee reliable delivery .
3.UDP is message-oriented and transmission network for one-time application of small amounts of data.
For packets is passed down to the application layer packets, neither split nor combined. For the length of the packet size, without any change. Reserved boundary!
4, UDP no congestion control, suitable for many real-time applications .
5.UDP header overhead small, 8B, TCP20B.
UDP header format:
UDP checksum:
UDP checksum: [too difficult]
