This field is the average, as continuously recalculated on the live object, of the per-interval delta values for CRC (cyclic redundancy check) errors — frames whose checksum did not match their contents, meaning the frame was corrupted somewhere on the wire, taken across the retained collection history for this stats object. Admins watch this to separate a genuinely sustained problem from one noisy interval — if DeltaAvg for crc on this interface is climbing, on this network-interface error table, rather than a one-off spike. For example, an average of 3 CRC errors per interval sustained over many polling cycles points at a chronic issue rather than a one-time glitch.