circuitswitching

Circuitswitching is a method of communication in which a dedicated communication path is established between two endpoints for the duration of a transmission. Once the circuit is established, the resources along the full path are reserved exclusively for that connection, and data can be transmitted at a continuous, agreed-upon rate. The circuit remains in use until the transmission ends and is then released for use by others.

The process typically involves a call setup phase in which signaling is used to route and reserve resources across the network. After the circuit is established, data flows in a steady stream with fixed bandwidth and predictable latency. When the transmission is complete, the circuit is torn down and the reserved resources are freed. This model contrasts with packet switching, where data is divided into packets that may traverse different paths and share network resources.

Circuit switching is most closely associated with traditional telephone networks (the public switched telephone network, or PSTN) and other services that require guaranteed, continuous bandwidth, such as leased lines and some ISDN bearer services. Some networks also use virtual circuits, where a logical path is established within a shared network, providing a connection-oriented service that mimics circuit switching but may rely on packet-switched infrastructure.

Advantages include predictable latency and bandwidth, low jitter during a connection, and straightforward quality-of-service handling for constant-bit-rate traffic. Disadvantages include poor efficiency for bursty data, slow or cumbersome call setup, and limited scalability or flexibility in handling variable traffic patterns. In modern networks, circuit switching is often complemented or replaced by packet-switching approaches for data, with circuit-oriented services retained for specific telephony uses.