Circuit switching is a term used in communication where the communicating nodes will be connected through a dedicated channel before any communication may take place. The methodology provides a full guarantee of the channel's full bandwidth and the connection is sustained for the entire session of the communication. The functionality in this case is similar to physical connection of the nodes. A very good example of the circuit switching is the analog telephone networking system.  The delay in bit at the time of connection is constant in this case.  The concept is useful that it helps in providing continuous transfer but the disadvantage is inflexibility of the use of associated bandwidth and connection for any other uses.  The circuit switching is used in telephone networks; in the analog system where the connection is made the before communication.