Virtual circuit switching
Virtual circuit switching is a packet switching methodology whereby a path is established between the source and the final destination through which all the packets will be routed during a call. This path is called a virtual circuit because to the user, the connection appears to be a dedicated physical circuit. However, other communications may also be sharing the parts of the same path.
Before the data transfer begins, the source and destination identify a suitable path for the virtual circuit. All intermediate nodes between the two points put an entry of the routing in their routing table for the call. Additional parameters, such as the maximum packet size, are also exchanged between the source and the destination during call setup. The virtual circuit is cleared after the data transfer is completed.
Virtual circuit packet switching is connection orientated. This is in contrast to datagram switching, which is a connection less packet switching methodology. Advantages of virtual circuit switching are:
Disadvantages of a virtual circuit switched network are:
Examples of virtual circuit switching are X.25 and Frame Relay.