backward explicit congestion notification (FR) (BECN)
Backward Explicit Congestion Notification (BECN) is an overload mechanism. This mechanism is used in frame relay( FR) networks and ATM networks.
In Backward Explicit Congestion Notification, the BECN data field, a 1-bit data field in the frame relay header, is used to indicate that the network is congested, in the opposite direction of the transmitted data frame. The network node that detects the overload informs the sending station, which can then lower its data rate. The overload mechanism is triggered by setting a bit in the header.