CircuitSwitched

Circuitswitched is a term used to describe a method of network communication in which a dedicated communication path is established between two endpoints for the duration of a session. During circuitswitched communication, the path is reserved and exclusively used by that session, providing a fixed bandwidth and a continuous route for the entire duration of the call.

In a circuitswitched network, a call setup procedure allocates resources across the network's switching elements and links to establish a circuit. Once established, data travels the same path until teardown, with the network maintaining a fixed capacity for the connection. The setup and teardown are coordinated by signaling protocols such as SS7 or ISDN Q.931. The result is predictable end-to-end latency and guaranteed bandwidth for the session.

Circuitswitched systems are contrasted with packet-switched networks, where data is divided into packets that share links and only use resources as needed. The main advantages are deterministic performance and straightforward quality of service for real-time traffic, such as voice. The main drawbacks are inefficiency when circuits are idle and longer setup times, as well as scalability limits in data-centric networks. Today, many networks favor packet switching; circuitswitched components remain in legacy public switched telephone networks and in some mobile infrastructures for voice and other real-time services.