This read-only counter, in cells, tracks the number of valid OAM cells in the ingress direction of this channel that were discarded at the class-of-service queue. An admin cares because losing OAM cells to congestion can blind fault-detection mechanisms like continuity checks, potentially delaying detection of a real connection failure precisely when the network is stressed. For example, if this counter is nonzero during a period when continuity check failures were also reported, the admin might consider that congestion-driven OAM cell loss contributed to delayed fault detection rather than an actual link break.