This counter tallies CLP0 (cell loss priority 0, i.e. 'do not discard') cells that the NRTS processor received and still discarded on this circuit. Because CLP0 cells are supposed to be the protected, high-priority traffic, any nonzero or rapidly climbing value here is a red flag that the circuit is oversubscribed or the buffer/threshold configuration is too tight, since even non-discard-eligible cells are being dropped. A network engineer watching a PVC degrade might see cktNrtsDiscardClp0 jump from 0 to several thousand over a polling interval and conclude the circuit's committed bandwidth is being exceeded, not just its burst allowance.