Datagram sockets support connectionless communications in the AF_INET and AF_INET6 address families. A datagram socket provides bidirectional data flow. However, datagram sockets do not ensure either secure or sequential data transfer. It is also possible that the data may be transferred more than once. A task that receives messages on a datagram socket may therefore possibly receive messages more than once and/or in a different order from that transmitted. The application is therefore responsible for checking and saving the received data. One important characteristic of datagram sockets is that the record limits of the transferred data are retained.
Datagram sockets are used to develop connectionless communications applications based on the UDP protocol.