Definition of Switched Virtual Circuit (SVC) in the Network Encyclopedia.

What is Switched Virtual Circuit?

Switched Virtual Circuit, also known as SVC, is a form of telecommunications service that provides a path between two nodes in a packet-switched network. The path is set up and configured at the beginning of a session and is dismantled at the end. Each new session requires a switching path to be established, and this path differs during each session depending on the available switches.

A switched virtual circuit (SVC) provides a temporary, point-to-point connection between the two nodes. SVCs offer the advantage of bandwidth on demand but suffer from some latency in establishing a connection. They are cheaper than permanent virtual circuits (PVCs) because they use whatever telco resources are available at a given time; after the session, these resources are released for other purposes. Because the actual switching path varies with each session, SVCs also suffer from inconsistent connection quality.

SVC for WAN links

SVCs are best used for WAN links that have low or irregular network traffic.

Difference between Switched Virtual Circuit (SVC) and Permanent Virtual Circuit (PVC)

Switched Virtual Circuits (SVCs) are temporary connections created for the purpose of information transfer. There are four steps to establish SVC connection viz. call setup, data transfer, Idle and call termination. Permanent Virtual Circuits (PVCs) are permanent connections established for the sole purpose of frequent as well as consistent data transfer. As it is like leased line, PVC connection do not require to be be established using call setup or termination states. PVC will be either in data transfer mode or in IDle mode.