Defining Connectionless And Connection-Oriented Conversations

The terms ‘connectionless’ and ‘connection-oriented’ are sometimes used in confusing ways. Let’s set the record straight in a way that would satisfy the demands of a network expert.

Connectionless And Datagram Mean The Same Thing

A connectionless protocol (or protocol layer) does not have a sequence number and acknowledgment scheme. That’s all. No sequence numbers means that a protocol is ‘connectionless’. It could also be referred to as a ‘datagram’.

Connection-Oriented And Reliable Mean The Same Thing

A connection-oriented protocol (or protocol layer) has sequence numbers and an expected acknowledgment process. If acknowledgments are not received then a retransmission will occur. In this way a connection-oriented protocol can guarantee delivery of data. That’s all. If a protocol has sequence numbers then it’s ‘connection-oriented’. It could also be referred to as a ‘reliable’ protocol.

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