2.3 Frame Relay
Frame relay was initially developed to use ISDN equipment to access packet switched services on a bearer (B) channel. However, frame relay can now be considered as a data service in its own right and it is essentially a packet-switched version of ISDN.
Frame relay consists of an efficient data transmission technique used to send digital information quickly and cheaply in a relay of frames to one or many destinations from one or many end-points. Network providers commonly implement frame relay for voice and data as an encapsulation technique, used between local area networks (LANs) over a wide area network (WAN). Each end-user gets access to a private line (or leased line) to a frame-relay node. The frame-relay network handles the transmission over a frequently changing path that is transparent to end users.
It has become an extremely popular WAN technology in the U.S. because it offers similar services to X.25 but is more efficient and cost effective.