Cisco ONS 15454 SDH - Perform a Hairpin Test on a Destination-Node Electrical Port (East to West)

1-28
Cisco ONS 15454 SDH Troubleshooting Guide, R5.0
July 2005
Chapter 1 General Troubleshooting
1.2.6 Perform a Hairpin Test on a Destination-Node Electrical Port (East to West)
Step 6 Resend test traffic on the loopback circuit with known-good cabling, a known-good card, and the
replacement FMEC card.
Step 7 If the test set indicates a faulty circuit, repeat all of the facility loopback procedures. If the faulty circuit
persists, contact the Cisco Technical Support. 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 8 If the test set indicates a good circuit, the problem is probably a defective FMEC card. Clear the facility
(line) loopback:
a. Click the Maintenance > Loopback tabs.
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 9 Complete the “1.2.6 Perform a Hairpin Test on a Destination-Node Electrical Port (East to West)”
procedure on page 1-28.
1.2.6 Perform a Hairpin Test on a Destination-Node Electrical Port (East to
West)
The hairpin test is performed on the cross-connect card in the network circuit. A hairpin circuit uses the
same port for both source and destination. Completing a successful hairpin through the card isolates the
possibility that the cross-connect card is the cause of the faulty circuit. Figure 1-16 shows an example
of a hairpin loopback on a destination-node port.
Figure 1-16 Hairpin on a Destination-Node Port
Note The ONS 15454 SDH does not support simplex operation on the XC-VXL cross-connect card. Two
cross-connect cards of the same type must be installed for each node.
Complete the “Create the Hairpin Circuit on the Destination-Node Port” procedure on page 1-29.
Destination
ONS Node
E1-N STM-NXC
Source
ONS Node
Intermediate
ONS Node
Test Set
E1-N XC STM-N E1-N XC STM-N
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