Cisco 7821 Cannot be re-resister in CME after reset

[kilias]

Hello everybody.

I encountered the following problem.

I had a working CME v10.0 running (Cisco 2911 IOS ver 153-3.M3) with 18 7821 phones registered to it.

Two hours ago , I had to reset 5 phones (voice register pool x ->reset). 4 out of five registered again without

any problem. However the fifth one keeps on restarting and will not register.

I enabled debug TFTP events on the router and I discovered that although the

remaining 4 IP phones which registered normally were requesting SEPXXXXXXXXX.cnf.xml

type of files from the CME, that fifth 7821 is requesting SEPXXXXXXXXX.cnf.xml.sgn which is not in the 

flash. I tried resetting the phone to its factory defaults (I had to tell someone else to do it because there is no access

to the phone physically and I do not know If the reset procedure was performed correctly). The phone however

continues to restart requesting still the same files. The reset was not performed correctly or there is something

else that I am missing?

Thank you in advance

[jabritt · Accepted solution]

You need to make sure you erase the security settings (ITL and CTL) and make sure you have the proper firmware on flash.

If you factory reset and are trying to upgrade it in too large of increments that can be a problem as well.

Erase the security settings, reset the phone, make sure it has profiles created.

Should register if connectivity and tftp settings are in DHCP.

[kilias]

Dear jabritt

The phone is in a remote location and cannot register to the CME after a reset command from

the CME's CLI. Is it possible to erase its security settings while the phone is NOT registered?

The proper firmware is in the right place and the tftp server is pointed to the right firmware files.

Thank you in advance

[kilias]

Dear jabritt

You were right. I managed to reset the phone and now it is registered .

Thank you