This attribute indicates whether a LOF (Loss of Frame) alarm state
is entered. A LOF alarm state is entered when LOF defects are
observed and accumulated for 2.5 seconds +/- 0.5 seconds or more.
A LOF defect occurs when seven or more consecutive incorrect
frame alignment patterns (4 multiframes) are received. 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 LOF alarm is cleared when framing has been achieved for 10
seconds +/- 0.5 seconds. The port goes into an operationalState of
disabled for the duration of the LOF alarm condition. While the
port is in the LOF alarm state, the node also transmits the far-end
RAI defect indicator on the out-going JT2 line.