Perform A Terminal Loopback On A Source-Node Optical Port; Create The Terminal Loopback On A Source-Node Optical Port; Figure 1-7 Terminal Loopback On A Source-Node Stm-N Port - Cisco ONS 15600 SDH Troubleshooting Manual

1.2.2 Perform a Terminal Loopback on a Source-Node Optical Port

Complete the
Step 7
page
1.2.2 Perform a Terminal Loopback on a Source-Node Optical Port
The terminal loopback test is only available on ASAP card optical and Ethernet ports. (This section will
only address the optical ports; Ethernet ports are covered in
Path With Loopbacks, page
To create a terminal loopback, create a bidirectional circuit originating on the node source optical port
and looping back on the node source optical port. You then proceed with the terminal loopback test.
Completing a successful terminal loopback to a node source port verifies that the circuit is good to the
source port.
Figure 1-7 Terminal Loopback on a Source-Node STM-N Port
Source
ONS Node
STM-N
Test Set
Caution Performing a loopback on an in-service circuit is service-affecting.
Terminal loopbacks require on-site personnel.
Note
Complete the

Create the Terminal Loopback on a Source-Node Optical Port

Step 1 Connect an optical test set to the ASAP card optical port you are testing:
Note
a.
b.
c.
Cisco ONS 15600 SDH Troubleshooting Guide, R8.0
1-10
"1.2.2 Perform a Terminal Loopback on a Source-Node Optical Port" procedure on
1-10.
1-29.) Terminal loopbacks are not available on STM-16 or STM-64 cards.
Figure 1-7 shows an example of a terminal loopback on a source optical port.
XC STM-N
"Create the Terminal Loopback on a Source-Node Optical Port" procedure on page
For specific procedures to use the test set equipment, consult the manufacturer.
If you just completed the "1.2.1 Perform a Facility Loopback or Payload Loopback on a
Source-Node Optical Port" procedure on page 1-7
hooked up.
If you are starting the current procedure without the optical test set hooked up to the source optical
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.
Adjust the test set accordingly. (Refer to manufacturer instructions for test-set use.)
Intermediate
ONS Node
STM-N XC STM-N
for an optical port, leave the optical test set
Chapter 1 General Troubleshooting
1.3 Troubleshooting an Ethernet Circuit
Destination
ONS Node
STM-N XC STM-N
1-10.
July 2010