This read-only Counter64 counts bytes received on this PM instance that the switch discarded outright, rather than forwarding or yellow-marking them. This is the counter an admin escalates on — sustained non-zero drops mean traffic on this flow point exceeded even the excess-rate allowance or hit a policy/resource limit, and whatever service rides this instance will show real loss; because it is drawn from this table's currently-accumulating, short-interval bin, it reflects only the last few minutes of activity, so it's the value to watch for a fast-forming problem rather than a long-term trend. On a 1 Gbps UNI feeding a business Ethernet Private Line, this might read 3,350,000 bytes over the last 15 minutes — a number an admin would divide by the bin length to sanity-check it against the port's 1,000,000,000-bps ceiling.