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Cisco ONS 15310-CL and Cisco ONS 15310-MA Troubleshooting Guide, R7.0
Chapter1 General Troubleshooting
1.6.1 Perform a Facility Loopback on a Source-Node Ethernet Po rt
1.6.1 Perform a Facility Loopback on a Source-Node Ethernet Port
The facility loopback test is performed on the node source port in the network circuit. Completing a
successful facility loopback on this port isolates the port as a possible failure point.
Note Facility loopbacks require on-site personnel.
Caution Performing a loopback on an in-service circuit is service-affecting.
Complete the “Create the Facility Loopback on the Source-Node Ethernet Port” procedure on page1-29.

Create the Facility Loopback on the Source-Node Ethernet Port

Step1 Connect a test set to the port you are testing.
Note For specific procedures to connect, set up, and use the test set equipment, consult the
manufacturer.
Use appropriate cabling to attach the Tx and Rx terminals of the test set to the port you are testing. The
Tx and Rx terminals connect to the same port.
Step2 Adjust the test set accordingly. (Refer to manufacturer instructions for test-set use.)
Step3 In CTC node view, double-click the CE100T-8 card to display the card view.
Step4 Click the Maintenance > Loopback tabs.
Step5 Choose OOS,MT from the Admin State column for the port being tested. If this is a multiport card,
select the appropriate row for the desired port.
Step6 Choose Facility from the Loopback Type column for the port being tested. If this is a multiport card,
select the appropriate row for the desired port.
Step7 Click Apply.
Step8 Click Yes in the confirmation dialog box.
Note It is normal for the “LPKTERMINAL (CE100T)” condition on page2-104 to appear during
loopback setup. The condition clears when you remove the loopback.
Step9 Complete the “Test and Clear the Facility Loopback Circuit” procedure on page1-29.

Test and Clear the Facility Loopback Circuit

Step1 If the test set is not already sending traffic, send test traffic on the loopback circuit.
Step2 Examine the traffic received by the test set. Look for errors or any other signal information that the test
set is capable of indicating.