This LAN internetworking protocol standard is a fast and efficient method of transmitting information from a user device to LAN bridges and routers. Though structured similar to that of LAPD, the frame header is replaced by a 2-byte Frame. The Frame Relay header contains the congestion and status signals which the network sends to the user and also the user-specified DLCI field, which is the destination address of the frame. Frame Relay forms a good substitue to both dedicated lines and X.25 networks for connecting LANs to bridges and routers. The success of the Frame Relay protocol is based on the following two factors.
a. virtual circuits can exist simultaneously across a given transmission line as they consume bandwidth only when they transport data and each device could operate at higher speeds by using more bandwidth.
b. With the advent of improved reliability of communication lines and increased error-handling sophistication at end stations, Frame Relay protocol could discard erroneous frames and eliminate time-consuming error-handling processing.
These factors make Frame Relay a favorite choice for data transmission, but its also necessary to test and determine that the system works properly and that data is not lost.