This integer sets the Unavailable Seconds count that, if exceeded over the current full-day Line-layer interval, triggers a statistical alarm, defaulting to 10 and applying identically to near-end and far-end — notably the same default as the 15-minute threshold rather than a scaled-up daily value. An admin cares because this unusually low daily threshold (matching the 15-minute one) means the device treats even a single 15-minute interval's worth of UAS accumulated anywhere across the whole day as alarm-worthy. For example, just 10 seconds of unavailability total across an entire day, whether concentrated in one interval or spread across several, is enough to breach this daily threshold.