This read-only TimeTicks value indicates the most recent time the jitter attenuator's FIFO buffer came within 4 bits of its limit on this T1/E1 line interface, or reports zero if that has not happened since system startup. Administrators use it to detect when the configured jitter attenuator (see t1e1CfgJitterAttenuator) is nearly overwhelmed by timing jitter, which can precede slips or bit errors on the line. For example, a recent non-zero timestamp here alongside reported line errors would point to insufficient jitter buffer depth as a likely cause.