Specifications

1-57
Cisco ONS 15454 Troubleshooting and Maintenance Guide
November 2001
Chapter 1 Alarm Troubleshooting
Two types of loopbacks are available: Facility and Terminal. Facility loopbacks troubleshoot ports only
and are generally performed locally or at the near end. Terminal loopbacks test ports and spans and are
often used for remote sites or far-end equipment. You can provision loopbacks through CTC.
Caution The CTC permits loopbacks to be performed on an in-service circuit. This operation is service
affecting.
Procedure: Clear the LBKFACILITY Alarm on the DS-3, DS-3E, DS3XM-6 or DS-1 Card
Step 1 Double-click the reporting card in CTC or right-click the reporting card in CTC and choose Open from
the menu.
Step 2 Click the Maintenance tab.
Step 3 Choose the Loopback Type column and click None.
Step 4 Click Apply.
1.3.81 LPBKFACILITY (OC-N)
• Not Alarmed (NA) (Condition)
A software facility loopback is active for a port on the reporting card.
Loopback is a commonly-used troubleshooting technique. A signal is sent out on a link or part of the
network and returned to the sending device. A troubleshooter can compare the quality of the sent signal
and the returned signal to determine the condition of an isolated circuit. By setting up loopbacks on
various parts of the network and excluding other parts, a troubleshooter can logically isolate the source
of the problem. For more information on loopbacks, see the “Network Tests” section on page 2-3.
Two types of loopbacks are available: Facility and Terminal. Facility loopbacks troubleshoot ports only
and are generally performed locally or at the near end. Terminal loopbacks test ports and spans and are
often used for remote sites or far end equipment. You provision loopbacks using CTC.
Procedure: Clear the LBKFACILITY Condition on the OC-N Card
Step 1 To remove the loopback alarm, double-click or right-click on the reporting card in the CTC. Choose
Open from the list of options.
Step 2 Click the Maintenance tab.
Step 3 Click the Loopback Type column and choose None from the menu.
Step 4 Click Apply.
1.3.82 LPBKTERMINAL (DS-N)
• Not Alarmed (NA) (Condition)