A transmission mode in which a network establishes a logical relationship, and often a predetermined path, for all frames or packets associated with an originating and destination address pair to travel.The path can be permanent or can exist for a single session.The public switched telephone network (PSTN) is connection-oriented.Transmission Control Protocol (TCP) is a connection-oriented protocol, where Internet Protocol (IP) is a connectionless datagram service. See also connectionless, frame, IP, packet, protocol, PSTN, session, and TCP.
A communications architecture that requires the establishment of a session between two nodes before transmission can begin. When the communications is completed, the session is ended (torn down). All circuit-switched networks are connection oriented because they require a dedicated channel for the duration of the session. The most ubiquitous circuit-switched network is the PSTN. In addition, packet-switched X.25, frame relay and ATM networks are also connection oriented, because they require receiving nodes to acknowledge their ability to support the transmission before data can be sent. In an IP network, the TCP transport protocol is connection oriented, requiring a three-way handshake in order to start transmitting data packets. Contrast with connectionless.