Connectionless mode transmission

Connectionless mode transmission: In a packet switched network, transmission in which each packet is encoded with a header containing a destination address sufficient to permit the independent delivery of the packet without the aid of additional instructions.

Note 1: A packet transmitted in a connectionless mode is frequently called a datagram.

Note 2: In connectionless mode transmission of a packet, the service provider usually cannot guarantee there will be no loss, error insertion, misdelivery, duplication, or out-of-sequence delivery of the packet. However, the risk of these hazards' occurring may be reduced by providing a reliable transmission service at a higher protocol layer, such as the Transport Layer of the Open Systems Interconnection--Reference Model.

Source: from Federal Standard 1037C