A circuit switching network is one that establishes a dedicated circuit between nodes & terminals before the users may communicate. Each circuit that is dedicated cannot be used by other callers until the circuit is released and a new connection is set up. Even, if no actual communication is taking place in a dedicated circuit then, than channel still remains unabailable to other users. Channels that are available for new calls to be set up are said to idle. Circuit switching is used for ordinary telephone calls. It allows communications equipment and circuits, to be shared among users. Each users has sole access to a circuit during network use.
COMMUNICATION USING CIRCUIT SWITCHING INVOLVES 3 PHASES:-