1-10
Cisco ONS 15454 SDH Troubleshooting Guide, R5.0
July 2005
Chapter 1 General Troubleshooting
1.2.1 Perform a Facility (Line) Loopback on a Source Electrical Port (West to East)
Note Facility, hairpin, and terminal loopback tests require on-site personnel.
1.2.1 Perform a Facility (Line) Loopback on a Source Electrical Port (West to
East)
The facility (line) loopback test is performed on the node source port in the network circuit; in this
example, the E1-N-14 port is the source. Completing a successful facility (line) loopback on this port
isolates the cabling, the electrical card, and the FMEC card as possible failure points. Figure 1-11 shows
an example of a facility loopback on a source E1-N-14 port.
Figure 1-11 Facility Loopback on a Circuit Source E1-N-14 Port
Caution Performing a loopback on an Unlocked circuit is service-affecting. To protect traffic, apply a lockout or
Force switch to the target loopback port. For more information about these operations, refer to the
Cisco ONS 15454 SDH Procedure Guide Chapter 15, “Maintain the Node.”
Note Electrical facility (line) loopbacks do not transmit an AIS condition in the direction away from the
loopback. Instead of an AIS, a continuance of the signal transmitted to the loopback is provided.
Complete the “Create the Facility (Line) Loopback on the Source Electrical Port” procedure on
page 1-10, then test and clear the loopback as instructed.
Create the Facility (Line) Loopback on the Source Electrical Port
Step 1 Connect an electrical test set to the port you are testing.
Step 2 Use appropriate cabling to attach the Tx and Rx terminals of the electrical test set to the FMEC
connectors or electrical connection panel for the port you are testing. The Tx and Rx terminals connect
to the same port.
Step 3 Adjust the test set accordingly.
Step 4 In node view, double-click the card to display the card view.
Step 5 Click the Maintenance > Loopback tab.
Step 6 Choose Unlocked,maintenance from the Admin State column for the port being tested.
Source
ONS Node
Destination
ONS Node
E1N STM-NXC STM-N E1NXC
Test Set
120192
To Next Page
Loading...
