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Cisco ONS 15454 Troubleshooting Guide, R8.5
 November 2009
Chapter 1      General Troubleshooting
1.4.2    Perform a Terminal Loopback on a Source-Node Optical Port
Step 5 Complete the “Test and Clear the Terminal Loopback Circuit” procedure on page 1-52.
Test and Clear the Terminal Loopback Circuit
Step 1 If the test set is not already sending traffic, send test traffic on the loopback circuit.
Step 2 Examine the test traffic being received by the test set. Look for errors or any other signal information 
that the test set is capable of indicating.
Step 3 If the test set indicates a good circuit, no further testing is necessary on the loopback circuit. Clear the 
terminal loopback state on the port:
a. Double-click the card in the source node with the terminal loopback.
b. Click the Maintenance > Loopback > Port tabs.
c. Select None from the Loopback Type column for the port being tested.
d. Select the appropriate state (IS; OOS,DSBLD; OOS,MT; IS,AINS) in the Admin State column for 
the port being tested.
e. Click Apply.
f. Click Yes  in the confirmation dialog box.
Step 4 Clear the terminal loopback circuit:
a. Click the Circuits tab.
b. Choose the loopback circuit being tested.
c. Click Delete. 
d. Click Yes  in the Delete Circuits dialog box. Do not check any check boxes.
Step 5 Complete the “Test the Optical Card” procedure on page 1-52. 
Test the Optical Card
Step 1 Complete the “Physically Replace a Traffic Card” procedure on page 2-273 for the suspected bad card 
and replace it with a known-good one.
Step 2 Resend test traffic on the loopback circuit with a known-good card.
Step 3 If the test set indicates a good circuit, the problem was probably the defective card. Return the defective 
card to Cisco through the RMA process. Contact Cisco Technical Support at 1 800 553-2447.
Step 4 Complete the “Physically Replace a Traffic Card” procedure on page 2-273 for the defective card.
Step 5 Clear the terminal loopback on the port before testing the next segment of the network circuit path:
a. Double-click the card in the source node with the terminal loopback.
b. Click the Maintenance > Loopback > Port tabs.
c. Select None from the Loopback Type column for the port being tested.
d. Select the appropriate state (IS; OOS,DSBLD; OOS,MT; IS,AINS) in the Admin State column for 
the port being tested.