Describe Circuit switching and message switching

Circuit Switching: A circuit switching network is one that establishes a dedicated circuit (or channel) between nodes and 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 circuits then, that channel still remains unavailable to other users. Channels that are available for new calls to be set up are said to be idle. Circuit switching is used for ordinary telephone calls. It allows communications equipment and circuits, to be shared among users. Each user has sole access to a circuit during network use.

Message Switching: Message switching was the precursor of packet switching, where messages were routed in their entirety and one hop at a time. It was first introduced by Leonard Kleinrock in 1961. Message switching system is nowadays mostly implemented over packet-switched or circuit-switched data networks.

Each block is received in its entity form, inspected for errors and then forwarded or re-transmitted. It is a form of store-and-forward network. Data is transmitted into the network and store in a switch. The network transfers the data from switch to switch when it is convenient to do so, as such the delays can happen. The source and destination terminal need not be compatible, since conversions are done by the message switching networks.