1-42
Cisco ONS 15454 SDH Troubleshooting Guide, R5.0
July 2005
Chapter 1 General Troubleshooting
1.3.2 Perform a Terminal (Inward) Loopback on a Source-Node Optical Port
1.3.2 Perform a Terminal (Inward) Loopback on a Source-Node Optical Port
The terminal (inward) loopback test is performed on the source-node optical port. For the circuit in this
example, the destination STM-N port in the source node. You first create a bidirectional circuit that starts
on the node source optical port and loops back on the node destination optical port. You then proceed
with the terminal loopback test. Completing a successful terminal loopback to a node destination port
verifies that the circuit is good up to the destination port. Figure 1-20 shows an example of a terminal
loopback on a source-node STM-N port.
Figure 1-20 Terminal Loopback on a Source-Node STM-N Port
STM-N cards placed in terminal loopback state display an icon in the CTC graphical user interface
(GUI), shown in Figure 1-21.
Figure 1-21 Terminal Loopback Indicator
Caution Performing a loopback on an Unlocked circuit is service-affecting.
Complete the “Create the Terminal (Inward) Loopback on a Source-Node Optical Port” procedure on
page 1-42.
Create the Terminal (Inward) Loopback on a Source-Node Optical Port
Step 1 Connect an optical test set to the port you are testing:
Note Refer to the manufacturer’s instruction for detailed information on connection and setup of the
optical test set.
a. If you just completed the “1.3.1 Perform a Facility (Line) Loopback on a Source-Node Optical
Port” procedure on page 1-39, 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-node
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.
Destination
ONS Node
STM-N STM-NXC
Source
ONS Node
Intermediate
ONS Node
STM-N STM-NXCSTM-N
Test Set
STM-N XC
90600
To Next Page
Loading...
