PVC
A PVC (Permanent Virtual Circuit) is a software-defined logical connection in a frame relay network. A feature of frame relay that makes it a highly flexible network technology is that users (companies or clients of network providers) can define logical connections and required bandwidth between end points and let the frame relay network technology worry about how the physical network is used to achieve the defined connections and manage the traffic. The end points and a stated bandwidth called a Committed Information Rate (Committed Information Rate) constitute a PVC, which is defined to the frame relay network devices. The bandwidth may not exceed the possible physical bandwidth. Typically, multiple PVCs share the same physical paths at the same time. To manage the variation in bandwidth requirements expressed in the CIRs, the frame relay devices use a technique called statistical multiplexing.