This read-only counter, in frames, tallies frames received that were discarded at ingress, for reasons the description names as policing or congestion. This is the actual damage counter for this connection's inbound direction, so a customer reporting dropped packets or retransmissions on this circuit should have this checked first, and it rising in step with casfVcCountReceivedDEs points specifically to policing rather than fabric congestion as the cause. This counter climbing at the same rate as ReceivedDEs, with no corresponding rise elsewhere in the switch's congestion counters, tells you the customer is simply oversubscribing their own contracted rate.