TR Troubleshooting - Multistation Access Unit (MAU) and Wiring Hub Problems

Does the failure symptom appear to be related to a specific MAU or  hub port failure?  Go to page 4.1. 

 Do the failure symptoms that appear to be related to a suspected bad  MAU or wiring hub module occur with multiple users or the complete  Token Ring network? 
 Go to page 4.2. 

Because this procedure is generic as to the MAU and wiring hub  manufacturer, for some of the troubleshooting steps mentioned on this page,  you should also reference the respective manufacturer's documentation for any  special predefined methods for checking configuration and for diagnostic  testing. 

In the case of some wiring hubs, you may have certain diagnostics  available that can help you locate a specific problem. If this type of diagnostics  is available, attempt to use it for fault isolation. 



4.1 A specific MAU or hub port appears to be encountering a failure.

Move the lobe cable from the suspected bad port to another port on the same MAU or wiring hub module. Before you move the lobe cable, make sure the new port is functioning. Next, retest the respective ring station or network peripheral on the new MAU or wiring hub port.

Did physically changing the port get rid of the failure symptom?

The suspected bad port is bad. Replace the respective MAU or hub module and retest the ring station or network peripheral for proper operation. If the failure symptom is gone, record the problem in the network maintenance and service log. If problems still exist, go to the next step .

If a failure still exists with the same ring station or network peripheral, re-attach the lobe cable to the original port and troubleshoot the respective lobe area for the assigned MAU or wiring hub port by going to page 2.



4.2 A suspected bad MAU or wiring hub module appears to be causing failure symptoms with multiple users or the complete Token Ring network.

Whether the failure symptom is solid or intermittent, remove the suspected bad MAU or wiring hub module and associated main ring path cabling sections from the ring configuration and then retest the ring.

Are the failure symptoms now gone?

The respective MAU, wiring hub module, or a main ring path cabling section is at failure. Replace the removed unit and cables with another unit and cables. Retest the new ring configuration. If no problems are encountered, record the problem in the network maintenance and service log. If problems still exist, go to the next step.

Even if your problem is now fixed, if you feel that one of the main ring path cabling sections did cause the problem, you can verify the problem by going to page 3. If you want to verify the MAU or wiring hub failure, you can do so with any available manufacturer diagnostics.

If failure symptoms still exist, reinsert the original MAU or wiring hub module and respective cables into the ring configuration.

Have you troubleshot and verified the integrity of the main ring path cabling?

Run a protocol analysis session to gain more conclusive fault isolation data by going to page 15.

Troubleshoot the main ring path cabling by going to page 3. 

  November 15, 1996

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Louis Ohland, Peter Wendt, William Walsh, David Beem, Tatsuo Sunagawa, Jim Shorney, Tim Clarke, Kevin Bowling, Tomáš Slavotínek, and many others.

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