This attribute indicates whether a Loss Of Signal (LOS) alarm state
has been entered. An LOS alarm state is entered when LOS defects
have been observed and accumulated for a period of 2.5 seconds +/-
0.5 seconds, or if an LOS defect is present when the criteria for
LOF failure declaration have been met. A LOS defect is declared
when 20+/-3 us of all-zeros pattern is detected. The LOS defect is
cleared when two valid framing words are detected and no Loss Of
Signal condition is detected during an interval of 20+/-3 us. If the
LOS defects are intermittently occurring, the LOS 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 Sonet/Sdh component goes into an operational state of disabled
until the LOS alarm condition is cleared. The LOS alarm state is
cleared after LOS defects have been absent for a period of 10
seconds +/- 0.5 seconds.
The losAlarm attribute is always set to off when the component has
been locked and left offline.