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Cisco ONS 15454 Troubleshooting Guide, R8.5
November 2009
Chapter 1 General Troubleshooting
1.2.8 Perform a Terminal Loopback on a Source-Node Electrical Port (East to West)
Note ONS 15454 DS-3 terminal loopbacks do not transmit an AIS in the direction away from the loopback.
Instead of AIS, a continuance of the signal transmitted into the loopback is provided. A DS3/EC1-48
card can be provisioned to transmit AIS for a terminal loopback if desired.
Depending upon your card type, complete the “Create the Terminal Loopback on a Source DS-1, DS-3,
DS3N-12, DS3i-N-12, or EC1 Port” procedure on page 1-41 or the “Create the Terminal Loopback on a
Source DS3E or DS3XM Port” procedure on page 1-43. Then test and clear the loopback as instructed.
Create the Terminal Loopback on a Source DS-1, DS-3, DS3N-12, DS3i-N-12, or EC1 Port
Step 1 Connect an electrical test set to the port you are testing:
a. If you just completed the “1.2.7 Perform an XC Loopback on a Source-Node OC-N STS (East to
West) Carrying an Electrical Circuit” procedure on page 1-36, leave the electrical test set hooked up
to the DS-N port in the source node.
b. If you are starting the current procedure without the electrical test set hooked up to the DS-N port,
use appropriate cabling to attach the Tx and Rx terminals of the electrical test set to the DSx panel
or the EIA connectors for the port you are testing. Both Tx and Rx connect to the same port.
Step 2 Adjust the test set accordingly. (Refer to manufacturer instructions for test-set use.)
Step 3 In CTC node view, click the Circuits tab and click Create.
Step 4 In the Circuit Creation dialog box, choose the type, such as STS, and number, such as 1.
Step 5 Click Next.
Step 6 In the next Circuit Creation dialog box, give the circuit an easily identifiable name such as DS1toDS4.
Step 7 Leave the Bidirectional check box checked.
Step 8 Click Next.
Step 9 In the Circuit Creation source dialog box, select the Node, card Slot, Port, and STS (or VT) where the
test set is connected.
Step 10 Click Next.
Step 11 In the Circuit Creation destination dialog box, use the same Node, card Slot, Port, and STS (or VT) used
for the source dialog box.
c. Click Next.
d. In the Circuit Creation circuit routing preferences dialog box, leave all defaults. Click Finish.
Step 12 Confirm that the newly created circuit appears in the Dir column as a two-way circuit.
Note It is normal for the “LPBKTERMINAL (DS1, DS3)” condition on page 2-174 to appear during
a loopback setup. The condition clears when you remove the loopback.
Note ONS 15454 DS-3 terminal loopbacks do not transmit an AIS in the direction away from the loopback.
Instead of AIS, a continuance of the signal transmitted into the loopback is provided. A DS3/EC1-48
card can be provisioned to transmit AIS for a terminal loopback if desired.