Datagram service

Datagram service

Datagram service is a service provided by IP at the Internet layer. It is a connectionless, best effort, unreliable, message delivery service. Many higher level protocols including TCP (a connection-oriented service) depend on IP's Datagram service, laying additional functionality on top. UDP uses IP's Datagram service as well.

Datagram service is often compared to a mail delivery service, the user only provides the destination address, but receives no guarantee of delivery, and no confirmation upon successful delivery.

Datagram service routes datagrams without first creating a predetermined path. There is also no consideration given to the order in which it and other datagrams are sent or received. In fact, many datagrams in the same group can travel along different paths before reaching the same destination.