12-22
Cisco ONS 15327 User Documentation, R3.3
June 2002
Chapter 12 Maintenance
Network Test Procedures
Figure 12-13 Facility loopback on a source XTC card
Caution
Performing a loopback on an in-service circuit is service-affecting.
Note
Loopbacks operate only on in-service ports.
Procedure: Create the Facility Loopback on the Source XTC Card
Step 1
Connect an electrical test set to the port you are testing. Use appropriate cabling to attach the transmit
(Tx) and receive (Rx) terminals of the electrical test set to the MIC card, which will interface with the
XTC card. Both transmit (Tx) and receive (Rx) connect to the same port. Adjust the test set accordingly.
Step 2
Set the port into facility loopback mode.
Note
It is normal for an alarm to appear during loopback setup. The alarm clears when you remove
the loopback.
Step 3
Proceed to the
“Test the Facility Loopback” procedure on page 12-22
.
Procedure: Test the Facility Loopback
Step 1
If the test set is not already sending traffic, send test-set traffic on the loopback.
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 loop, no further testing is necessary with the facility loopback. Clear the
loopback circuit before testing the next segment of the network circuit path. Proceed to the
Hairpin Circuit on a Source Node XTC Card” procedure on page 12-24
.
Step 4
If the test set indicates a faulty circuit, the problem may be a faulty MIC card, faulty XTC card, or faulty
cabling from the DS-N port. Proceed to the
“Test the DS-N Cabling” procedure on page 12-23
XTC
XTC
MIC
OC-N
ONS 15327
Source
OC-N
MIC
ONS 15327
Destination
DS-N
DS-N
Facility loopback
Test Set A
76187
Summary of Contents for ONS 15327
Page 22: ...Contents xxii Cisco ONS 15327 User Documentation June 2002 I N D E X ...
Page 30: ...Figures xxviii Cisco ONS 15327 User Documentation June 2002 ...
Page 44: ...Procedures xlii Cisco ONS 15454 Installation and Operations Guide R3 2 June 2002 ...
Page 540: ...Glossary GL 16 Cisco ONS 15327 User Documentation R3 3 June 2002 ...