The Discard Eligibility (DE) bit is used to indicate that a
frame has lower importance than other frames. The DE bit is part
of the Address field in the Frame Relay frame header.
DTE devices can set the value of the DE bit of a frame to 1
to indicate that the frame has lower importance than other
frames. When the network becomes congested, DCE devices will
discard frames with the DE bit set before discarding those that
do not. This reduces the likelihood of critical data being
dropped by Frame Relay DCE devices during periods of
congestion.