This attribute indicates whether a LOF (Loss of Frame) alarm state
has been entered. The LOF alarm state is entered when LOF defects
(for DS1: 2 out of 5 framing bits in error; for E1: 3 consecutive
frame alignment patterns in error) have been detected for 3 seconds
+/- 0.5 second . If the LOF defects are intermittently occurring, the
LOF 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 until the LOF
alarm state is cleared. The condition is cleared when framing has
been achieved for 10 seconds +/- 0.5 second.