This read-only counter, in cells, tracks the number of valid CLP=0, high-priority, cells in the ingress direction of this channel that were discarded specifically because the class-of-service queue overflowed. An admin cares because CLP=0 cells being discarded at all signals a serious congestion problem, since normally only lower-priority CLP=1 cells should be shed first when a CoS queue overflows. For example, if this counter starts incrementing on a channel carrying critical voice or signaling traffic, the admin should treat it as an urgent congestion signal, since even nominally protected high-priority cells are now being lost.