This 64-bit counter tallies a hardware data-parity check failing on a frame received off the ring fiber, over the current, still-running 15-minute window. This flags a hardware/optics-level fault on the ring receive path rather than a network-layer condition, so a rising count here points toward this node's SRP linecard, transceiver, or fiber connector needing physical inspection or replacement rather than a routing or congestion fix. Seeing this jump from 0 to a steady trickle of a few counts per interval right after a transceiver was reseated would point straight back at that optic as the likely culprit.