RFC 768 J. Postel ISI 28 August 1980
0 7 8 15 16 23 24 31 +--------+--------+--------+--------+ | Source | Destination | | Port | Port | +--------+--------+--------+--------+ | | | | Length | Checksum | +--------+--------+--------+--------+ | | data octets ... +---------------- ...
User Datagram Header Format
0 7 8 15 16 23 24 31 +--------+--------+--------+--------+ | source address | +--------+--------+--------+--------+ | destination address | +--------+--------+--------+--------+ | zero |protocol| UDP length | +--------+--------+--------+--------+
the creation of new receive ports,
receive operations on the receive ports that return the data octets and an indication of source port and source address,
and an operation that allows a datagram to be sent, specifying the data, source and destination ports and addresses to be sent.