Frame relay is a packet switched network, commonly used at the Datalink layer (layer 2) of the OSI model. Generally the concept of Permanent Virtual Circuits (PVCs) are used to form logical end-to-end links mapped over a physical network. Switched Virtual Circuits are also part of the Frame relay specification but are rarely applied in the real world.
Datalink Connection Identifiers or DLCIs are a locally significant numeric value to represent each end point. Multiple PVCs can be mapped to the same physical end point. It is often provisioned with a Committed Information Rate (CIR) and a burstable component sometimes known as Extended Information Rate(EIR).
Frame Relay was designed to make more efficient use of existing physical resources, thereby allowing the overprovisioning of data services to customers from the Telecommuncations companies as most clients are unlikely to be utilising a data sevice 100 percent of the time.
Frame relay is/was often sold by Telcommunications companies to businesses looking for a cheaper alternative than leased lines, its use in different areas depending on governmental and telecommunication's companies polices.
External links: