Cisco ONS 15454 - 1.2.3 Perform an XC Loopback on a Destination-Node OC-N STS (West to East) Carrying an Electrical Signal

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Cisco ONS 15454 Troubleshooting Guide, R8.5
November 2009
Chapter 1 General Troubleshooting
1.2.3 Perform an XC Loopback on a Destination-Node OC-N STS (West to East) Carrying an Electrical Signal
d. Click Yes in the Confirm Switch dialog box.
Note After the active cross-connect goes into standby mode, the original standby card becomes
active and its ACT/SBY LED turns green. The former active card becomes standby and its
ACT/SBY LED turns amber.
Step 2 Resend test traffic on the loopback circuit.
Step 3 If the test set indicates a faulty circuit, the problem is probably the defective card. Return the defective
card to Cisco through the RMA process. Contact Cisco Technical Support at 1 800 553-2447 and
proceed to Step 4. If the test does not indicate a faulty circuit, proceed to Step 5.
Step 4 Complete the “Physically Replace an In-Service Cross-Connect Card” procedure on page 2-274 for the
defective card.
Step 5 If the test set indicates a good circuit, the cross-connect card might have had a temporary problem that
was cleared by the side switch. Clear the hairpin circuit:
a. Click the Circuits tab.
b. Choose the hairpin circuit being tested.
c. Click Delete.
d. Click Yes in the Delete Circuits dialog box. Do not check any check boxes.
e. Confirm that the hairpin circuit is deleted from the Circuits tab list.
Step 6 Complete the “1.2.3 Perform an XC Loopback on a Destination-Node OC-N STS (West to East)
Carrying an Electrical Signal” procedure on page 1-18.
1.2.3 Perform an XC Loopback on a Destination-Node OC-N STS (West to East)
Carrying an Electrical Signal
The XC loopback tests whether any problem exists on the circuit’s OC-N span, isolating this span from
others present on the card. The loopback occurs on the cross-connect card in a network circuit.
Figure 1-13 shows an example of an XC loopback on a destination OC-N port. The traffic pattern looks
similar to a terminal loopback but traffic is only carried on one STS instead of affecting the entire port.
Note The XC loopback on an OC-N card does not affect traffic on other circuits.
Note XC loopbacks do not require on-site personnel.
Note You can perform an XC loopback on either the circuit source working or the protect port of a 1+1
protection group.