This read-only Gauge reports the number of Unavailable Seconds encountered by this DS1 interface in the current 15-minute interval, counting seconds during which the line was considered fully unavailable for service (per the standard definition, typically ten consecutive severely errored seconds trigger entry into an unavailable state). This is the most severe performance category, representing actual outage time rather than degraded-but-functioning performance. An admin calculating whether a DS1 circuit is meeting an availability SLA for the current interval would check dsx1CurrentUASs directly, since even a small nonzero value here represents real service downtime rather than just quality degradation.