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A previously registered IP phone is not being seen in the Emergency Responder known phones list

Core Issue

During the phone tracking process there is an opportunity for a phone to drop off the list of known phones. This can be caused by a phone being in the process of registering itself to a Cisco CallManager while the phone tracking process is running.

For more details, refer to the Phone Sometimes Disappears in CER section of Troubleshooting Emergency Responder.


The most common reasons for phones re-homing or resetting are network problems between the phone and the Cisco CallManager or bugs in the phone load.

To determine the phone load running on these phones, perform these steps:

  1. Select Phone > Settings > 4 > App Load ID.        
  2. Check for any bugs in the Bug Toolkit regarding phones resetting.      
  3. Check for any possible or excessive broadcasts between the phone and the Cisco CallManager server. You may want to sniff the network to find this out.      
  4. If the problem is with more than one phone, look for any patterns in the behavior. For example, do other phones on the problem phone's subnet display this problem?     

    Anything common among the phones that have problems could lead to the cause.

For more information about resolving Cisco Emergency Responder, refer to these documents:

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‎06-22-2009 05:31 PM
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