Create The Facility (Line) Loopback On The Source Ds-N Port; Test And Clear The Facility (Line) Loopback Circuit - Cisco ONS 15454 Troubleshooting Manual

Chapter 1 General Troubleshooting
Caution Performing a loopback on an in-service circuit is service-affecting. To protect traffic, apply a lockout or
Force switch to the target loopback port. For more information about these operations, refer to the
Cisco ONS 15454 Procedure Guide.
DS-3 facility (line) loopbacks do not transmit an alarm indication signal (AIS) condition in the direction
Note
away from the loopback. Instead of a DS-3 AIS, a continuance of the signal transmitted to the loopback
is provided.

Create the Facility (Line) Loopback on the Source DS-N Port

Step 1 Connect an electrical test set to the port you are testing.
Use appropriate cabling to attach the Tx and Rx terminals of the electrical test set to the EIA connectors
or DSx panel for the port you are testing. The Tx and Rx terminals connect to the same port. Adjust the
test set accordingly.
In node view, double-click the DS-N card to open the card view.
Step 2
Depending upon the card type, click the Maintenance > Loopback tabs, Maintenance > DS1 tabs, or
Step 3
Maintenance > DS3 tabs.
Choose OOS_MT from the State column for the port being tested. If this is a multiport card, select the
Step 4
appropriate row for the port being tested.
Choose Facility (Line) from the Loopback Type column for the port being tested. If this is a multiport
Step 5
card, select the appropriate row for the port being tested.
Click Apply.
Step 6
Click Yes in the confirmation dialog box.
Step 7
Note
Complete the
Step 8

Test and Clear the Facility (Line) Loopback Circuit

Step 1 If the test set is not already sending traffic, send test traffic on the loopback circuit.
Examine the traffic received by the test set. Look for errors or any other signal information that the test
Step 2
set is capable of indicating.
Step 3 If the test set indicates a good circuit, no further testing is necessary with the facility loopback.
Double-click the card to open the card view.
Step 4 Depending upon the card type, click the Maintenance > Loopback tabs, Maintenance > DS1 tabs, or
Maintenance > DS3 tabs.
Step 5 Choose None from the Loopback Type column for the port being tested.
November 2004
It is normal for the "LPBKFACILITY (DS1, DS3)" condition on page 2-141
loopback setup. The condition clears when you remove the loopback.
"Test and Clear the Facility (Line) Loopback Circuit" procedure on page
1.3.1 Perform a Facility (Line) Loopback on a Source DS-N Port (West to East)
Cisco ONS 15454 Troubleshooting Guide, R4.6
to appear during
1-9.
1-9