Virtual - Circuit - Switching

VIRTUAL - CIRCUIT - SWITCHING

 Virtual circuit switching is a combination of  Datagram switching and Circuit Switching. 

This type of switching includes some features of Datagram switching and some of Circuit Switching, I will try to explain u with a figure :

 

DATAGRAM                 Virtual-Circuit                  Circuit-Switching

         |                                     |                                              |

Network Layer             Data Link Layer                Physical Layer

Resource allocation             -------                       Resource allocation

Packetization                                                       Three Phases

 

Addressing  in Virtual - Circuit Switching :

 In the header section of Packet is local jurisdiction, not the end- to end jurisdiction.

There are 2 type of addresses used in Virtual Circuit Switching :

Global and Local address(VCI)

  Global Address : Source or destination needs to have a global add., a address that can be unique in the scope of the whole Network

Global address in VCN is used only to create VCI.

VCI ( Virtual Circuit Identifier ) : actually used for data transfer, a small number that has only switch scope.