Circuit switching is a method whereby a dedicated physical path, or circuit, is established and maintained between two nodes or locations for the duration of a connection. Circuit switched networks are often referred to as connection-oriented networks because the dedicated circuit must be estalished first, or "nailed up", before information can be sent.
Telephone networks are typically circuit switched, because voice traffic requires the consistent timing of a single, dedicated physical path to keep a constant delay on the circuit. The plain old telephone system (POTS) is the largest circuit switched network. The original GSM network is also circuit switched. Although GPRS introduced packet switching in the GSM network.