Hi!

Check the CCM application logs and see what's the reason code for the unregistered device. It can be a network or a phone issue.

For Reason Codes definition check this link:

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_tech_note09186a0080111ac2.shtml#t11

Also I would check that all the 7912s are running the latest firmware just in case!

Regards,

Tere.

Hi.

1st place where you can see what is happening - status messages on the phone(don't have 7912 near me but will have on Monday).

2nd Also you can try to verify whether everything is OK with network settings.

3rd try "show logging" command on cisco switch to which this phone is connected to see if the interface is not reseting.

4th Try to sniff traffic to see what the phone is requesting(or what it is not getting)

5th If you're using CCM 4.x - you can see phone resets in the event viewer in the Application logs.(or the reason which was before the phone starts to reset)

6th Try to reset to factory defaults:

Procedure A:

-Press **2. The phone displays "Do you want to reset all system settings to default values?"

-Press the Yes softkey.

•Procedure B:

-Press **#. If your phone displays "Enter Admin Password," enter your password and then press the Enter softkey. Make sure that an unlocked padlock icon appears in the upper-right corner of your LCD.

-Scroll to Erase Configuration.

-Press the Yes softkey and then press the Save softkey.

HTH