Connectionless versus Connection-Oriented Routing
Connection-Oriented Routing sets up a virtual circuit between the sender and receiver.
The virtual circuit is one that appears to the application software to use point-to-point circuit switching, even though it actually uses store and forward switching.
In connection-oriented routing a temporary virtual circuit is defined between the sender and receiver.
The network layer makes one routing decision when the connection is established, and all the packets follow the same route.
All packets in the same message arrive at the destination in the same order in which they were sent (sequence numbers are not needed)
Connection-oriented routing has greater overhead than connectionless routing, because the sender must first “open” the circuit sending a control packet that instructs all the intervening devices so to establish the circuit routing.
Likewise, when the transmission is complete, the sender must “close” the circuit.