2.3.5 Frame Relay

2.3.5 Frame Relay
Frame Relay, a packet-switching protocol supporting T1 and T3, was designed to support the Broadband Integrated Services Digital Network (B-ISDN). The specifications for Frame Relay address some of the limitations of X.25. As with X.25, Frame Relay is a packet-switching network service, but Frame Relay was designed around newer, faster fiber-optic networks. Unlike X.25, Frame Relay assumes a more reliable network. This enables Frame Relay to eliminate much of the X.25 overhead required to provide reliable service on less reliable networks. Frame Relay relies on higher-level network protocol layers to provide flow and error control. To use Frame Relay, you must have special Frame-Relay-compatible connectivity devices (such as Frame-Relay-compatible routers and bridges).
Frame Relay typically is implemented as a public data network and therefore is regarded as a WAN protocol. Frame Relay provides permanent virtual circuits, which supply permanent virtual pathways for WAN connections. Frame Relay services typically are implemented at line speeds from 56Kbps up to 1.544Mbps (T1). Customers typically purchase access to a specific amount of bandwidth on a Frame Relay service, for which the customer is guaranteed access.