This gauge counts Far End Block Errors reported back by the remote end of an E3 link during the current 15-minute interval, reflecting block errors the far end detected in what it received from this side; it does not increment while failure defects are present, and is valid in Direct cell mapping mode. It's the E3 equivalent of a mirror telling you how the signal you're sending looks from the other end. An admin suspecting a one-way transmit problem would watch this counter to see if the far end is reporting errors even though local receive counters look clean.