Verilink AS2000: The Basics (880-502981-001) Product Manual - Manual (Page 86)

Monitoring and Troubleshooting
5-20 Verilink Access System 2000: The Basics
Perform
Application
Equipment
Loopback
An equipment or data port loopback checks the cable integrity
between the AS2000 system and customer equipment. If a
equipment or data port LED is red, install a loopback plug and
perform a loopback test.
1. If the Eqpt or Data port LED is red, install a loopback plug in
the EQ port.
If the Eqpt LED or Data port changes from red to green:
2. Check application equipment and associated cables.
If the Eqpt or Data port LED stays red:
3. Replace the module, CIM, or both.
CSU Mode
Troubleshooting
The Equipment and Net LEDs of the application module monitor the
status of the incoming T1 signals, from both the equipment and
network sides of the application module.
During normal operation both LEDs are green, indicating the
application module is receiving acceptable signals from both
directions. (T1 only: If the application modules are used with DIUs
in a T1 multiplexer mode, the Equipment LED remains green).
A red Net LED indicates a failure in the incoming direction from the
network:
• Excessive bipolar violations (BPVs) or CRC errors in the
incoming signal.
• Loss of the incoming signal (LOS) from the network (faulty
cabling from the network interface, or faulty circuit or
application module on the network).
• The application module cannot frame up on the incoming
signal (LOF condition).
• A Yellow Alarm (RAI) was received from the far-end application
module.
The Stat LED of the application module is red when any of the
above conditions exists. The LED indicates that an application
module alarm state was reported to the management software (if
enabled).
If the Net LED and Stat LED are both red, troubleshoot the telco
circuit and the application module at each end. Use the loopback
plugs, testing the signal-sending functions of the application
modules, isolating the fault to the application modules or the
circuit.
A red Equipment LED on an application module, indicates trouble
with the local equipment. These faults are:
• Excessive bipolar violations (BPVs) or CRC errors in the
incoming signal.