3Com SuperStack II PathBuilder S330 Reference Manual page 179

Table 10 Alarms Common to Several Modules (continued)
Alarm Meaning
FEAC Loopback A DS3 overhead function that
allows the system to be
enabled or disabled for
responding to Far End Alarm
Condition commands from the
central office. When enabled,
the DS3 line loopback is put up
upon instruction from the
central office. The system
removes the loopback upon
instruction or after 15 minutes.
Idle Signal The line has not been
provisioned for service. No data
will pass on a line with an idle
signal.
In Band Loopback A loopback is configured on
the port. Loopbacks are for
troubleshooting only and
should not be present under
normal operating conditions.
Link Down Summary informational alarm
to indicate one or more alarms
on this link are active.
Link Up Summary informational alarm
to indicate all alarms on the
physical link are cleared.
Local Card A loopback is configured on
Loopback the port. Loopbacks are for
troubleshooting only and
should not be present under
normal operating conditions.
Loss of Cell Loss of cell
Delineation(LOCD) delineation—possibly a
framing or timing problem.
Loss of Signal(LOS) Cannot detect a signal at a
configured port. This alarm is
applicable to DS3 UNI, E3 UNI,
OC3/STM-1 UNI, T1 IMA UNI,
and E1 IMA UNI ports.
Network Card A loopback is configured on
Loopback the port. Loopbacks are for
troubleshooting only and
should not be present under
normal operating conditions.
(continued)
Managing System Alarms
Troubleshooting Steps
Check with your service provider to
determine the reason for the loopback.
Check the configuration of the terminal
equipment, or have your service
provider check their equipment and
make sure it is provisioned for service.
If you are not troubleshooting the port,
turn off the loopback.
Information only.
Information only.
If you are not troubleshooting the port,
turn off the loopback.
Check the reference clock source.
Compare parameters between local
and service provider end. Check the
physical layer.
Check the cable between the interface
port and the service provider's
equipment/terminal equipment. Check
cable connections. Check transmit and
receive pairs for proper connection.
Check terminating equipment. Call
your service provider.
If you are not troubleshooting the port,
turn off the loopback.
169