Installation guide

4-9
Cisco IGX 8400 Series Installation Guide, Release 9.3.3 and Later Releases
OL-1165-06
Chapter 4 Troubleshooting the IGX
Troubleshooting an IGX Node
Troubleshooting Bipolar Errors, Frame Slip Errors, and Out-of-Frame Errors
A bipolar error indicates excessive bipolar errors on the trunk. a frame slip error indicates excessive
frame slips on the trunk. An out-of-frame error indicates excessive out-of-frame errors on the trunk.
Step 1 Use the dsplog command to determine the date, time of day, and duration of the alarm.
Step 2 Use the dsptrkerrs command at each end of the trunk to quantify errors, and determine whether they
are unidirectional or bidirectional.
Step 3 Use the dsptrkhist command at each end of the trunk to collect historical information on line errors.
Step 4 Use the clrtrkalm command to clear trunk alarms.
Step 5 Contact the Cisco TAC for assistance. Cisco personnel can monitor line errors and might advise
disruptive testing to be scheduled with the telephone carrier. For more information, refer to the
“Obtaining Technical Assistance” section on page xxiii.
Step 6 Call the telephone carrier and request span testing. Ask the carrier to perform bit error rate (BER) tests
using multiple test patterns, including standard quasi, all 1, and 3 and 24 patterns.
Step 7 If the telephone carrier is unable to isolate the problem on the span, contact Cisco TAC for assistance.
For more information, refer to the “Obtaining Technical Assistance” section on page xxiii.
Troubleshooting Packet Drops
Time-stamped and non-time-stamped packet drop errors indicate that packet drops have exceeded the
threshold for generating an alarm.
Step 1 Use the dsplog command to determine when the dropped packet alarm threshold was exceeded, and to
determine the duration of the alarm.
Step 2 Use the dspload command alarm to determine the current loading of this trunk.
Step 3 Make a note of steps taken and call Cisco TAC. For more information, refer to the “Obtaining Technical
Assistance” section on page xxiii.
Troubleshooting a Loopback
Step 1 Determine if company personnel are performing span tests with CSU loopbacks, demarcation, or DSX
panel.
Step 2 If company personnel are performing loopback tests, ask them to indicate when they have completed
testing, and monitor the system to ensure that the loopback indication disappears when testing is
complete.
Step 3 If company personnel are not performing loopback tests, the telephone carrier most likely has the E1
span in loopback mode.