Virtual circuit
Virtual circuits are logical paths established between two devices. Depending on how they are set up, virtual circuits include the following types:
Permanent virtual circuits (PVCs)—Preconfigured by network administrators and maintain until being manually removed.
Switched virtual circuits (SVCs)—Analogous to dialup connections. They are dynamically set up or cleared on an as-needed basis through protocol negotiation.
PVCs are used far more than SVCs.