This attribute displays whether an AIS (Alarm Indication Signal) alarm state has been entered. The AIS Alarm state is entered when AIS defects have been observed and accumulated for 2.5 seconds +/ - 0.5 seconds. An AIS defect is detected after having received less than 3 zeros in a 2048 bit period (for 8pDS1Atm cards: when both an Out Of Frame condition exists and a 1's density of at least 99.9% is present for a time T, where 3 ms T 75 ms; for 8pE1Atm cards: when both an Out Of Frame condition exists and fewer than three 0's have been received in 512 bit periods). If the AIS defects are intermittently occurring, the AIS defect accumulator is decremented at a rate of 1/10 of the incrementing rate (alarm integration ratio of 1/10), with all measurements based on a 200 ms polling cycle. The port goes into an operational state of disabled for the duration of an AIS alarm state. The AIS alarm state is cleared when AIS defects are absent for 10 seconds +/- 0.5 seconds.