250 CHAPTER 15: T1-F INTERFACE CONFIGURATION COMMANDS
ft1 alarm-threshold
Syntax ft1 alarm-threshold { ais { level-1 | level-2 } | lfa { level-1 | level-2 | level-3 | level-4 }
| los { pulse-detection | pulse-recovery } value }
undo ft1 alarm-threshold
View T1-F interface view
Parameter ais: Sets the alarm threshold of alarm indication signal (AIS), which can be level-1
and level-2.
■ The level-1 keyword specifies to generate an AIS alarm when the number of 0s
in the bit stream of an SF or ESF frame is less than or equal to 2.
■ The level-2 keyword specifies to generate an AIS alarm when the number of 0s
is less than or equal to 3 in the bit stream of an SF frame or less than or equal
to 5 in the bit stream of an ESP frame.
By default, level-1 AIS alarm threshold applies.
lfa: Sets the loss of frame align (LFA) alarm threshold, which can be level-1,
level-2, level-3, and level-4.
■ The level-1 keyword specifies to generate an LFA alarm when two of four
frame alignment bits are lost.
■ The level-2 keyword specifies to generate an LFA alarm when two of five
frame alignment bits are lost.
■ The level-3 keyword specifies to generate an LFA alarm when two of six frame
alignment bits are lost.
■ The level-4 keyword applies only to ESF frames. It specifies to generate an LFA
alarm when errors are detected in four consecutive ESF frames.
By default, level-1 LFA alarm threshold applies.
los: Sets a loss of signal (LOS) alarm threshold, which can be pulse-detection (for
the pulse detection duration threshold with LOS) and pulse-recovery (for the
pulse threshold with LOS).
The threshold of pulse-detection, in units of pulse intervals, ranges from 16 to
4,096 and defaults to 176.
The threshold of pulse-recovery, ranges from 1 to 256 and defaults to 22.
If the number of the pulses detected during the total length of the specified pulse
detection intervals is smaller than the pulse-recovery threshold, a LOS alarm
occurs. For example, if the two thresholds take their defaults, a LOS alarm is
created if the number of pulses detected within 176 pulse intervals is less than 22.
Description Use the
ft1 alarm-threshold command to set LOS, AIS, or LFA alarm thresholds
on the T1-F interface.
