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Cisco ONS 15327 Troubleshooting Guide, R3.4
April 2003
Chapter1 General Troubleshooting
Identify Points of Failure on an OC-N Circuit Path
Figure1-15 Facility Loopback on an Intermediate-Node OC-N Port
Caution Performing a loopback on an in-service circuit is service-affecting.
Procedure: Create the Facility Loopback on an Intermediate-Node OC-N Port
Step 1 Connect an optical test set to the port you are testing:
a. If you just completed the “1.3.3 Perform a Terminal Loopback on a So ur ce-N od e O C-N P o rt”
section on page 1-27, leave the optical test set hooked up to the OC-N port in t he so urc e no de .
b. If you are starting the current procedure without the optical test set hooked up to the OC-N port, use
appropriate cabling to attach the Tx and Rx terminals of the optical test set to the port you are
testing. Both Tx and Rx connect to the same port.
c. Adjust the test set accordingly.
Step 2 Use CTC to set up the facility loopback circuit on the port being tested:
a. Click the Circuits tab and click the Create button.
b. Give the circuit an easily identifiable name, such as OCN1toOCN3.
c. Set circuit Type and Size to th e n ormal preferences.
d. Leave the Bidirectional check box checked and click the Next button.
e. In the Circuit Source dialog box, fill in the source Node, card Slot, Port, and Ty pe where the test
set is connected and click the Next button .
f. In the Circuit Destination dialog box, fill in the destination Node, card Slot, Port, and Type (the
OC-N port in the intermediate node) and click the Finish button.
Step 3 Confirm that the newly created circuit appears on the Circuits tab lis t as a two-wa y circu it.
Note It is normal for a LPBKFACILITY condition to appear during a loopback setup. The conditi on
clears when you remove the loopback.
Step 4 Create the facility loopback on the destination port being tested:
a. Go to the node view of the intermediate node:
Choose View > Go To Other Node from the menu bar.
Choose the node from the drop-down list in the Select Node dialog box and click the OK button.
b. In node view, double-click the card that requires the loopback, suc h as the destination OC-N ca rd in
the intermediate node.
Destination
ONS Node
OC-N OC-NXTC
Source
ONS Node Intermediate
ONS Node
OC-N OC-NXTC
Test Set
OC-N XTC OC-N
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