Virtual Circuit Switching
Connection oriented virtual circuit conducive to hop-by-hop flow control protocol in which QoS resources such as switch buffers and bandwidth are allocated at each switch.
Connection request from host A to host B contains address for B and a VCI (in this case 5) which switch 1 uses to identify future packets that A wants to send to B.
Switch 1 assigns new port and VCI for link from switch 1 to switch 2 and creates lookup table for routing future packets from host A.
Connection request makes its way through network to B which accepts (or rejects) the connection and sends notice back to A.
Connection is terminated by sending a teardown message which deletes the lookup tables throughout the network