This Counter32 counts external RAI (Remote Alarm Indication) AAL2 Type3 packets received, which are sent upstream by an entity that detected a persisting defect constituting a received signal failure. A rising count signals that the far-end equipment on this bearer connection is reporting a service interruption in the direction toward this VISM, effectively a backward-facing fault notification. An admin seeing calls fail on a particular connection would check this counter to see if the remote side is signaling that it detected the outage first.