Test Jacks
Test Commands
3166-A2-GB20-20
Table 4-6. Troubleshooting (2 of 2)
Symptom
Possible Cause
A failure message
Internal DSU/CSU problem.
appears followed
by an 8-digit code
( x x x x x x x x )
Mgmt link is down
1. The manager configuration is
mismatched with the
DSU/CSU configuration.
2. The manager's link layer
protocol is not running.
Two test jacks are located on the front panel: Net Mon (Network Monitor) In, and
Net Mon Out.
Net Mon In nonintrusively monitors the signal going into the network.
Net Mon Out nonintrusively monitors the signal coming from the network.
Net
Mon
In
Out
98-15942
The test commands enable you to run loopbacks and test patterns on the
DSU/CSU, and to test the front panel LEDs. These tests can help you isolate
areas of trouble if you are having problems with your DSU/CSU.
To access all Test commands from the Test branch, press F2 to select Test from
the top-level menu screen.
DSU ESF
Stat
Test
F1
F2
March 1999
Solutions
Record the 8-digit code, then
contact your service
representative.
1. Check that the configurations
2. Start the link layer protocol.
Cnfig
F3
Monitoring and Testing
are matched.
4-15