This read-only Counter64 counts frames — not bytes — received on this PM instance that the switch accepted. Pairing it with the accepted-bytes counter on the same instance lets an admin derive the average accepted frame size, which flags whether the link is carrying many small control/voice frames or fewer large bulk-data frames; because it is drawn from the current, still-open 24-hour bin for today, the number keeps climbing until midnight rollover, so it should be read as "so far today" rather than a finished daily total. On a 10 Gbps aggregation trunk carrying multiple EVCs, this might read 13,800 frames over today so far, which an admin would cross-check against the matching byte counter to see if average frame size looks normal for that service.