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This chapter describes how to diagnose problems. When a troubleshooting table in this chapter recommends replacement, refer to the procedures in Chapter 5, "Repair and Replacement."
The IGX operating system software does most of the IGX monitoring and maintenance. The only action that qualifies as preventative maintenance is checking the power supplies.
You cannot directly measure voltages on the AC power supplies in an IGX node. If a problem exists with one of the supplies, one or both the DC and AC LEDs turns off. Refer to the chapter on repair and replacement for instructions on re-seating or replacing an AC power supply.
After you install new or additional cards in the node, check the LEDs on the power supplies to make sure the cards have not put an excessive load on the power supplies.
This section describes elementary troubleshooting procedures and briefly describes the commands used when troubleshooting an IGX node. (These commands are described in detail in the Cisco StrataCom Command Reference.) This set of procedures is not exhaustive and does not take into account any of the diagnostic or network tools available to troubleshoot the IGX node.
This section contains the following topics:
 | Caution A lit FAIL LED on a card indicates that an error was detected. Try resetting the light with the resetcd f command. If the FAIL LED lights up again, use Table 4-1 to find the cause and call the WANBU TRT at Customer Engineering to obtain information on isolating the problem and possibly replacing a component. Refer to Appendix D for information on how to return defective components. |
| Symptom | Probable Cause | Remedy | |||
|---|---|---|---|---|---|
1.
| No indicators on IGX boards lit- console screen blank. LEDS on power supplies not lit. | 1. . | IGX circuit breakers off. | 1. | Switch on power switch. |
2. | Switch off, then switch on the power switch to reset the breaker. Check to see if any overload condition exists (shorted connections, crow-barred power supplies). | ||||
2. | IGX power cord dislodged from plug. | 3. | Reconnect power cord to AC receptacle. | ||
3. | Power supplies not functioning. | 4. | Replace power supplies | ||
2. | Front card FAIL indicator lit | 1. | Front card experienced an error:
| 1. | Indicates an error occurred. Resetting the card with the resetcd f command is suggested first. If the LED comes on again, call the WANBU TRT at Customer Engineering.
NOTE: If an NPM fails in a non-redundant IGX system the system must be rebooted. |
3. | Front card indicator lit—replacement card does not fix problem. | 1. | Defective backplane is possible. | 1. | If a new card does not fix problem, the backplane may be suspect (very uncommon failure). Contact the WANBU TRT at Customer Engineering. |
4. | SDI card FAIL indicator lit. | 1. | SDI card failed:
| 1. | Indicates an error occurred. Check alarm status of card. Re-seat card. Resetting the card with the resetcd f command is suggested first. If the LED comes on again, call the WANBU TRT at Customer Engineering. |
5. | ALM, BTM,UFM, ARM, CVM, LDI, BC-E1 or BC-T1 FAIL indicator lit-replacement card does not fix problem. | 1. | Defective backplane is possible (very uncommon). | 1. | If new card does not fix the
NOTE: All cards plug into the system backplane, and if this backplane is defective, it could cause a fault to appear on any card. |
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| 2 | Blown backplane fuse (very uncommon) | 1 | See backplane fuse section in the chapter titled "Repair and Replacement." |
6. | Power Supply AC or DC Okay LED off. | 1. | Possible power supply defect. | 1. | Re-seat supply per instructions in the chapter titled "Repair and Replacement." Remove and replace power supply if defective. |
2. | PE-BC wiring or card defective. | 1. | If power supplies output check out, then PE-BC wiring connections or card is suspect. | ||
2. | Make sure the plug connection to the PE-BC card is secure; tighten if it is not. | ||||
3. | If the plug connection is secure and the Power Supply Monitor FAIL indicator is still lit, then remove and replace the SCM card. | ||||
7. | Command line display incorrectly shows wrong IGX system type. | 1. | Jumper switch W6 in wrong position. (See installation chapter) | 1. | To indicate an IGX 16 node, the jumper must be in place. To indicate an IGX 32 node, the jumper must be absent. |
2. | SCM circuitry that reads W6 setting may be defective. | 1. | Verify SCM circuitry with a known good SCM. | ||
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8. | Neither of the Power Supply "Okay" LEDs are lit. | 1. | Defective fan or fans in cooling assembly is allowing the temperature in the enclosure to rise above 40º C. | 1. | Verify fan tray fans are working. If not, replace tray according. |
2. | Defective power supply fan in power supply allowing the power supply temperatures to rise above 40º C. | 1. | If the system cooling fan assembly is functioning correctly, then a power supply fan is suspect. Remove cover over power supplies to determine if fan is rotating. Replacing a power supply fan is not a field repair. Replace the supply. | ||
2. | Issue a dsppwr command at the control terminal to check to see if the power supply fans are rotating, if not, remove and replace the power supply with the defective fan. | ||||
3. | If power supply fans are functioning, then the power supply temperature sensor is defective. Remove and replace the temperature sensor | ||||
3. | Defective SCM card | 1. | If both the enclosure fan assembly and the power supply fans are working correctly (see symptom 6, probable causes 1, 2 and 3), then the SCM card is suspect. | ||
2. | Remove and replace the SCM card. | ||||
9. | Console screen blank, IGX indicator lights lit. | 1. | Control terminal switched off. | 1. | Switch on the control terminal. |
2. | Control terminal power cord disconnected. | 2. | Reconnect the control terminal power cord to 208/240 vac power outlet. | ||
3. | RS-232 cable loose or disconnected from the Control Terminal port on the SCM, or from the control terminal. | 3. | Reconnect the RS-232 cable to Control Terminal port on the SCM back card or to the control terminal itself. | ||
4. | Control terminal malfunctioning. | 4. | Refer to the control terminal manufacturer's manual. | ||
10. | Printer not functioning | 1. | Printer switched off. | 1. | Switch on the printer. |
2. | Printer out of paper. | 2. | Renew the paper supply. | ||
3. | Printer power cord disconnected. | 3. | Reconnect the printer cord to 208/240 vac power outlet. | ||
4. | RS-232 cable loose or disconnected from the Control Terminal port on the SCM, or from the printer. | 4. | Reconnect RS-232 cable to the Control Terminal port on the SCM back card or to the printer itself. | ||
5. | Printer malfunctioning. | 5. | Refer to the printer manufacturer's manual. | ||
11. | Modem not functioning. | 1. | Modem switched off | 1. | Switch on the modem. |
2. | Modem power cord disconnected. | 2. | Reconnect modem power cord. | ||
3. | RS-232 cable loose or disconnected from the Control Terminal port on the SCM, or from the modem. | 3. | Reconnect the RS-232 cable to the Control Terminal port on the SCM back card or the modem itself. | ||
4. | Telephone hookup cable disconnected. | 4. | Reconnect the telephone hookup cable. | ||
5. | Modem malfunctioning. | 5. | Refer to the modem manufacturer's manual. | ||
6. | DIP switches not set correctly. | 6. | Refer to the modem manufacturer's manual. | ||
12. | DFM is not functional. | 1. | DFM has been not been enabled by Stratacom. | 1. | Contact the WANBU TRT at Customer Engineering. |
13. | DFM has been enabled but still does not function. | 1. | DFM only runs on speeds up to 64Kbps. | 1. | Readjust the speed. |
14. | Background noise or music sounds choppy. | 1. | VAD problem.-VDP needs sensitivity adjustment | 1. | Contact the WANBU TRT at Customer Engineering. |
15. | High speed modem drops to low speed. | 1. | ADPCM is taking over. | 1. | Contact the WANBU TRT at Customer Engineering. |
16. | Bundled (Frame Relay) connections have failed. | 1. | One or more bundled connections have failed. | 1. | Contact the WANBU TRT at Customer Engineering.
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The initial mode of troubleshooting the IGX node uses the console alarms displayed on the console screen. Table 4-2 provides you with a procedure for isolating the alarms and thereby isolating the fault. Any repair to the IGX node must be performed by Cisco-qualified personnel.
| Caution When using Table 4-2 for troubleshooting, call the WANBU TRT at Customer Engineering before performing any disruptive testing, or attempting to repair the IGX node, to ensure that you have isolated the correct problem area, and also to enable Cisco personnel to provide you with assistance in performing the necessary procedures. |
| Symptom | Probable Cause | Remedy | ||
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MAJOR/MINOR alarm flashing on affected console screen. |
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| 1. | Use dspnw command to identify the node(s). |
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| 2. | Use vt command to place yourself at the affected node, and use dspalms to identify the alarm type. |
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| a.If the alarm display indicates a failed connection, go to probable cause 1. |
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| b.If the alarm display indicates a failed circuit line, go to probable cause 2. |
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| c.If the alarm display indicates a failed trunk, go to probable cause 3. |
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| d.If the alarm display indicates a failed card, go to probable cause 4. |
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| e.If the alarm display indicates an unreachable node, go to probable cause 5. |
| 1.
| Failed connection. | 1. | Use the dspcons command to identify which connections have failed and to determine the remote end connection assignments. |
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| 2. | Use the dsplog command to determine the cause of failure of the connections. These failures could consist of failed circuit lines, trunks cards, or clock over speeds. |
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| a. If the connections have failed due to a circuit line failure, go to probable cause 2. |
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| b.If the connections have failed due to a packet line failure, go to probable cause 3. |
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| c. If the connections have failed due to a card failure, go to probable cause 4. |
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| d. If connections have failed due to a clock over speed condition, go to probable cause 5. |
| 2. | Failed circuit line. | 1. | Use the dspclns command to identify the circuit line number and failure type. |
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| a.If the failure is a circuit line local CGA (no pulses received at the local end of circuit line) go to probable cause 2a. |
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| b.If the failure is a circuit line remote CGA (no pulses received at the remote end of circuit line), go to probable cause 2B. |
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| c.If the failure is circuit line frame slips (indicating excessive frame slips on the T1 between the IGX node and the PBX) go to probable cause 2C. |
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| d.If the failure is circuit line bipolar errors (indicating excessive bipolar errors on this circuit line) go to probable cause 2D. |
| 2A | Circuit line local CGA. | 1. | Use the dsplog command to determine date, time of day, and the duration of the CGA alarm. |
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| 2. | Determine if the PBX T1 subrate or the PBX E1 interface went down at the time the CGA alarm was logged by the IGX node. |
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| 3. | Check cabling between IGX node and the PBX and make necessary repairs if defective. |
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| 4. | Make a note of the steps taken and call the WANBU TRT at Customer Engineering. |
| 2B | Circuit line remote CGA. | 1. | Refer to remedies for probable cause 2A. |
| 2. | Circuit line frame slips. | 1. | Use the dsplog command to determine date, time of day, and duration of the frame slip alarm. Also determine if the clock source for this line has changed due to line failure in the network. |
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| 2. | Use the dspclnerrs command to quantify frame slips and rate information. |
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| 3. | Use the dspclnhist command to obtain historical information on frame slips. |
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| 4. | Use the dspcurclk command to identify the current clock source and path to the current clock source. |
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| 5. | Use the clrclnalm command to clear the circuit line alarms |
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| 6. | Make a note of the steps taken, and call the WANBU TRT at Customer Engineering. |
| 2 | Circuit bipolar errors. | 1. | Use the dsplog command to determine when the bipolar error threshold was exceeded, and the duration of the alarm. |
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| 2. | Use the dspclnerrs command to quantify the bipolar errors. |
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| 3. | Use the dspclnhist command to obtain historical information on bipolar errors. |
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| 4. | Check cabling between IGX node and the PBX for loose connections, and tighten it if it is loose. |
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| 5. | Use the clrclnalm command to clear line alarms. |
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| 6. | Make a note of the steps taken, and call the WANBU TRT at Customer Engineering. |
| 3. | Failed trunk. | 1. | Use the dsptrks command to identify the remote end node name, trunk numbers at each end, and the type of failure. |
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| a. If the display shows a communication failure, go to probable cause 3A. |
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| b.If the display shows a local CGA, go to probable cause 3B. |
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| c.If the display shows a remote CGA, go to probable cause 3C. |
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| d.If the display shows a bipolar error, go to probable cause 3D. |
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| e.If the display shows a frame slip error, go to probable cause 3E. |
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| f.If the display shows an out-of-frame error, go to probable cause 3F. |
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| g.If the display shows a time-stamped packet drop error, go to probable cause 3G. |
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| h.If the display shows a non time-stamped packet drop error, go to probable cause 3H. |
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| i.If the display shows a loop-back, go to probable cause 3I. |
| 3A | Communication Failure. | 1. | Use the dsplog command to determine when the communication failure or CGA occurred, and identify connections which may have failed due to lack of bandwidth on an alternate route. |
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| 2. | Use the dsptrkerrs command at each end of the packet line to quantify errors, and determine if they are unidirectional or bidirectional. |
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| 3. | Call telephone carrier and request span testing. Ask the carrier to perform BER tests using multiple test patterns, including standard quasi, all 1, and 3 and 24 patterns. |
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| 4. | Make a note of the steps taken, and call the WANBU TRT at Customer Engineering. |
| 3B | Local CGA—indicates no pulses at the local end of the trunk. | 1. | Refer to probable cause 3A remedies. |
| 3C | Remote CGA—indicates no pulses at the remote end of the trunk. | 1. | Refer to probable cause 3A remedies |
| 3D | Bipolar errors—indicates excessive bipolar errors on this trunk. | 1. | Use the dsplog command to determine the date, time of day, and the duration of the alarm. |
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| 2. | Use the dsptrkerrs command at each end of the trunk to quantify errors, and determine whether they are unidirectional, or bi-directional. |
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| 3. | Use the dsptrkhist command at each end of the trunk to collect historical information on line errors. |
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| 4. | Use the clrtrkalm command to clear trunk alarms. |
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| 5. | Call the WANBU TRT at Customer Engineering for assistance. Cisco personnel can monitor line errors, and may advise disruptive testing to be scheduled with telephone carrier. |
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| 6. | Call telephone carrier and request span testing. Ask the carrier to perform BER tests using multiple test patterns, including standard quasi, all 1, and 3 and 24 patterns. |
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| 7. | If telephone carrier is unable to isolate the problem on the span, contact Customer Support for assistance. |
| 3E | Frame slip errors indicates excessive frame slips on this trunk | 1. | Refer to probable cause 3D remedies. |
| 3F. | Out-of-frame errors—indicates excessive out-of-frame errors on the trunk. | 1. | Refer to probable cause 3D remedies |
| 3G | Time-stamped packet drops— | 1. | Use the dsplog command to determine when the dropped packet alarm threshold was exceeded, and determine the duration of the alarm. |
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| 2. | Use the dspload command alarm. to determine the current loading of this trunk. |
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| 3. | Make a note of steps taken and call Customer Support. Refer to probable cause 3G remedies. |
| 3H | Non time-stamped packet drops—indicates that non time -stamped packet drops have exceeded the threshold for generating an alarm. |
| Refer to probable cause 3G remedies. |
| 3I. | Loop-back. | 1. | Determine if company personnel are performing span tests with CSU loop-backs, demarc, or DSX panel. |
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| 2. | If company personnel are performing loop-back tests, ask them to indicate when they have completed testing, and monitor the system to ensure that the loop-back indication disappears when testing is complete. |
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| 3. | If company personnel are not performing loop-back tests, telephone carrier most likely has the E1 span in loop-back mode. |
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| 4. | Call telephone carrier to verify that they are testing the E1 span, and ask them to indicate when they have completed their tests. Monitor the system to ensure that the loop-back indication disappears when testing is completed. |
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| 5. | Make a note of the alarm steps taken, and call Customer Support. |
| 4. | Failed cards—indicates the number of cards that have failed. | 1. | Use the dspcds command to determine which card has failed, along with its status (active or standby). |
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| 2. | Use the dsplog command to determine time of day the card failed and whether or not any connections using this card are also in a failed condition. |
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| 3. | If the failed card is an HDM or LDM card, use the dspbob command at each end of the connection using this card to verify that data is passing. For a CDP, CVM, or UVM, use the dspchstats command. |
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| 4. | If a card has failed, make a note of the steps taken, and call Customer Support. |
| 5. | Unreachable node—shows the number of unreachable nodes in the network. | 1. | At any node, use the dsplog command to determine the date and time of day that the node became unreachable. A node is usually unreachable due to a trunk failure or a power outage. |
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| 2. | Contact personnel at that node to determine whether or not there was a power failure at the time logged by the IGX node. |
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| 3. | If there was a power failure, check that NPM comes up and run diagnostics. |
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| 4. | If there was not a power failure, call Customer Support. |
| 6. | Clock Overspeed. | 1. | Use the dspbob command to determine the incoming baud rate for this connection. |
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| 2. | Use the dspcon command to verify that the console incoming baud rate is the same as the configured baud rate. |
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| 3. | Reconfigure the incoming baud rate to match the configured baud rate. |
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| 4. | Make a note of the steps taken, and call Customer Support. |
The first step in troubleshooting the IGX node is to check the condition of the system. This is done by displaying alarm conditions throughout the system. In order to see a summary of all of the alarms present on an IGX node, use the dspalms (display current node alarms) command is used. The alarms summary includes the following:
To display alarms enter the command dspalms.
If the screen indicates a failure, refer to the commands in Table 4-3 to further isolate the fault.
| Failure | Diagnostic Commands |
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Connections | dspcons (display connections) |
Line Alarms | dspclns (display circuit lines) |
| dsptrks (display trunks) |
Cards | dspcds (display cards) |
Power Monitor/Fans | dsppwr (display power supply status) |
Remote Node | dspnw (display network) |
Unreachable Nodes | dspnw (display network) |
Remote Node Alarms | dspnw (display network) |
When a card indicates a failed condition on the alarm summary screen, use the dspcds command to display the status of the cards on a node. The information displayed for each card type includes the slot number, software revision level, and the status of the card. (Note that you cannot use the dspcds command in a job.)
All the possible status descriptions for each card type appear in Table 4-4.
| Card Type | Status | Description | |
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All card types (including CVM) | Active |
| Active card |
| Active—F |
| Active card with non terminal failure. |
| Standby |
| Standby card |
| Standby—F |
| Standby card with non terminal failure. |
| Standby—T |
| Standby card performing diagnostics.
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| Standby—F-T |
| Standby card with non terminal failure performing diagnostics. |
| Failed |
| Card with terminal failure. |
| Unavailable |
| Card is present but it may be in any of the following states: |
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| 1. | The node does not recognize the card (may need to be re-seated). |
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| 2. | The card is running diagnostics. |
| Down |
| Downed card. |
| Empty |
| No card in that slot. |
| Active—T |
| Active card performing diagnostics. |
NPM | Same status as for all card types, plus: |
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| Updating |
| Standby NPM downloading the network configuration from an active NPM. |
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| NOTE: Red FAIL LED flashes during updating. |
| Cleared |
| NPM is preparing to become active. |
| Loading Software |
| There are downloader commands that appear when the system is down- loading software to the NPM. |
To display cards enter the following command:
Refer to the Cisco StrataCom Command Reference for more information.
For detailed information on these commands, see the troubleshooting chapter in the Cisco StrataCom Command Reference.
Loopback tests are available to help diagnose the state of the IGX system. The commands for activating these tests are as follows:
For detailed information on these commands, see the Cisco StrataCom Command Reference.
The HDM/SDI or LDM/LDI card set can be tested as a pair at the local node using external test equipment such as a Bit Error Rate Tester (BERT). This can be useful in isolating "dribbling" error rates to either the cards, the frame relay data input, or the transmission facility. This test checks the data path from the electrical interface at the port through the card set to the CELLBUS in both directions of transmission.
To perform this test, proceed as follows:
Step 1 Disconnect the data cable connection to the SDI or LDI and connect the BERT in its place.
Step 2 Set up an internal loopback on the frame relay port to be tested using the Add Local Loopback (addloclp) command.
Step 3 Turn on the BERT, make sure it indicates circuit continuity, and observe the indicated error rate.
Step 4 If there are any errors indicated, first replace the back card and retest. If the errors remain, then replace the front card and retest.
Step 5 When the test is complete, disconnect the BERT and reconnect the data cable. Release the local loopback by using the Delete Loopback (dellp).
Step 6 Repeat at the node at the other end of the connection if necessary.
Posted: Thu Oct 10 09:17:15 PDT 2002
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