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Cisco ONS 15454 SDH Troubleshooting Guide, R5.0
July 2005
Chapter 1 General Troubleshooting
1.4.5 Perform a Facility (Line) Loopback on a Destination-Node Ethernet Port
Test and Clear the Ethernet Facility (Line) Loopback Circuit
Step 1 If the test set is not already sending traffic, send test traffic on the loopback circuit.
Step 2 Examine the traffic 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 with the facility loopback. Clear the
facility (line) loopback from the port:
a. Click the Maintenance > Loopback tab.
b. Choose None from the Loopback Type column for the port being tested.
c. Choose the appropriate state (Unlocked; Locked,disabled; Unlocked,automaticInService) from the
Admin State column for the port being tested.
d. Click Apply.
e. Click Yes in the confirmation dialog box.
Step 4 Clear the facility (line) 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 Ethernet Card” procedure on page 1-76.
Test the Ethernet Card
Step 1 Complete the “Physically Replace a Traffic Card” procedure on page 2-271 for the suspected bad card
and replace it with a known-good one.
Caution Removing a card that currently carries traffic on one or more ports can cause a traffic hit. To avoid this,
perform an external switch if a switch has not already occurred. See the “2.10.2 Protection Switching,
Lock Initiation, and Clearing” section on page 2-260 for basic instructions. For detailed information,
refer to the Cisco ONS 15454 SDH Procedure Guide Chapter 15, “Maintain the Node.”
Step 2 Resend test traffic on the loopback circuit with a known-good card installed.
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. Log into the Cisco Technical Support Website at
http://www.cisco.com/techsupport for more information or log into
http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml to obtain a directory of toll-free Cisco
TAC numbers for your country.
Step 4 Complete the “Physically Replace a Traffic Card” procedure on page 2-271 for the faulty card.
Step 5 Clear the facility (line) loopback on the port:
a. Click the Maintenance > Loopback tab.
b. Choose None from the Loopback Type column for the port being tested.