3Com CoreBuilder 7000, Installation & Start?Up Manual, Page: 53 / 150

4-Port Interface Module LEDs 53
Figure 11
DS-3 Status LEDs
Table 13
DS-3 Status LEDs
LED Color Description
LOS
Loss of Signal Green
On:
There is a signal on Rx (normal state).
Off:
No signal on Rx (problem with Rx).
FERF
Far End Rx Failure
Signal Yellow On: FERF in incoming frames (the peer reports
about its Rx problem).
Off:
No FERF in incoming frame.
AIS
Alarm Indication
Signal Blue
On:
AIS signal is present for at least 5 sec. (the
peer reports about its problem).
Off: No AIS signal present for at least 5 sec.
(normal state).
LOF
Loss of Frame Red
On:
LOF is present for at least 5 sec. (problems
with Rx).
Off: No LOF for at least 15 sec.