This attribute displays whether a LOS (Loss of Signal) alarm state
is 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. An LOS defect is declared at the JT2 line interface when
the input data is zero for 20 - 32 clock cycles. 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.
An LOS failure alarm is cleared when the LOS defect is absent for a
period of 10 seconds +/- 0.5 seconds. The JT2 port goes into an
operationalState of disabled for the duration of the LOS alarm
condition. While the port is in the LOS alarm state, the port also
transmits the far-end RAI defect indicator on the out-going JT2 line.