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Cisco ONS 15454 SDH Troubleshooting Guide, R5.0
July 2005
Chapter 1 General Troubleshooting
1.3.6 Perform a Facility (Line) Loopback on a Destination-Node Optical Port
Create the Facility (Line) Loopback on a Destination-Node Optical Port
Step 1 Connect an optical test set to the port you are testing:
Note Refer to the manufacturer’s instructions for detailed information on connection and setup of the
optical test set.
a. If you just completed the “1.3.5 Perform a Terminal (Inward) Loopback on an Intermediate-Node
Optical Ports” procedure on page 1-52, leave the optical test set hooked up to the source-node port.
b. If you are starting the current procedure without the optical test set hooked up to the source 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.
Step 2 Adjust the test set accordingly.
Step 3 Use CTC to set up the hairpin circuit on the test port:
a. In node view, click the Circuits tab and click Create.
b. In the Circuit Creation dialog box, choose the type and size, such as VC HO.
c. Click Next.
d. In the next Circuit Creation dialog box, give the circuit an easily identifiable name such as
STMN1toSTMN5.
e. Leave the Bidirectional check box checked. Leave the default value for State.
f. Click Next.
g. In the Circuit Creation source dialog box, select the same Node, Slot, Port, VC, and Tug where the
test set is connected.
h. Click Next.
i. In the Circuit Creation destination dialog box, use the same Node, Slot, Port, VC, and Tug used for
the source dialog box.
j. Click Next.
k. In the Circuit Creation circuit routing preferences dialog box, leave all defaults.
l. If the VC Optimization dialog box appears, leave all defaults.
m. Click Finish.
Step 4 Confirm that the newly created circuit appears on the Circuits tab list and that it is described in the Dir
column as a two-way circuit.
Note It is normal for the “LPBKFACILITY (STM1E, STMN)” condition, page 2-170 to appear during
a loopback setup. The condition clears when you remove the loopback.
Step 5 Create the facility (line) loopback on the destination port being tested:
a. Go to the node view of the destination node:
• From the View menu choose Go To Other Node.
• Choose the node from the drop-down list in the Select Node dialog box and click OK.