This read-create INTEGER, as a percentage from 0 to 100, sets the tail-drop threshold for traffic marked with Drop Precedence 1, a middle drop-priority class. An admin typically sets this threshold lower than the DP0 threshold, so DP1 traffic starts getting dropped at a shallower queue-fill level than the most protected class, providing differentiated congestion handling. For example, an admin might set this threshold to 80 percent, meaning DP1-marked packets start being tail-dropped once the queue is 80 percent full, well before the queue fills completely.