This is the upper 32 bits of a 64-bit cell counter tracking ingress ATM cells on this channel that had the EFCI congestion bit set to 1 and were discarded at the class-of-service queue, even though they had already passed UPC/PCR traffic-policing checks. Because it only supplies the high-order half of the value (the low 32 bits live in cwacsIngEFCI1Discard, the full value in cwacsHCIngEFCI1Discard), a management station polling a busy trunk avoids the 32-bit counter wrapping before it can be sampled, while EFCI=1 discards flag that downstream congestion is being signaled back yet cells are still being dropped at this queue. An admin troubleshooting voice-quality complaints on a heavily loaded PVC would watch this high-order word alongside its low-order counterpart to confirm cell loss is climbing over many billions of cells without the raw 32-bit value rolling over unnoticed.