Frame relay is a transmission system used to support computer networks, operating in wide area network|Wide Area Networks (WAN). Typically, it provides permanent connections, either point-to-point or point-to-multipoint (i.e., Nonbroadcast Multiple Access), operating at medium speeds from 2.4 Kbps to 44.736 Mbps.
Frame relay is a layer 2 system, configured by a service provider and often in a labor-intensive manner. It was originally intended to be a low-to-medium-speed feeder service to Asynchronous Transfer Mode (ATM), but proved so attractive, and simpler than ATM, that industry groups established working FR specifications before ATM work was done. FR networks are widespread.
Multiprotocol label switching (MPLS) offers greater functionality than FR, but is easier to implement and modify. While FR will persist for as long as legacy computers do not replace FR interfaces with MPLS, it is becoming less common. MPLS has a more robust fault recovery framework, and is also intended to be used with specified quality of service.