CP3905 unregistered in CUCM Issue

[bryg0d]

Hi everyone, can someone help me with my issue.

One of the phone is our office suddenly goes Unprovisioned. Upon checking in CUCM it was unregistered. I tried to register it again by deleting the phone and adding the same phone but to no avail. It was configured with the same DN and other settings but still unregistered. The phone was getting the correct IP in voice vlan DHCP pool. 

Device: CP3905

CUCM ver: 12.5.1

[Leo Laohoo]

If the phone has an IP address, enter the IP address into a web browser and go to the Networks tab. 

Look at the details in there.  Are they are all relevant and correct?

[bryg0d]

It's says refuse to connect. But I can ping the IP address. Any work around on this?

[Leo Laohoo]

Try:

http://192.168.90.41

And this is only happening to one phone only?

[Carlo Poggiarelli]

Hi,

Try to factory reset the phone. For some reason it could have lost certificate to trust the cucm tftp or for corrupted configuration.

Please let us know 

HTH

Regards

Carlo

[bryg0d]

Hi Carlo,

Already tried to reset multiple times but still the same result. Could this be possibly a faulty unit?

[Carlo Poggiarelli]

Hi,

Did you check that the device name you added on CUCM is correct?

And.. as suggested by @Leo Laohoo , browse the IP address of the phone and check NW config and logs from there.

Please let us know.

Regards

Carlo

[bryg0d]

Hi Carlo,

As checked, Phone is not getting TFTP Server IP and Unified CM 1 on the network setup. Aside from that everything looks the same. 

[Carlo Poggiarelli · Accepted solution]

Hi,

That could be the reason, so try to put the cucm address as 150 dhcp option on the scope serving that network or insert it manually by accessing the admin settings on the phone and selecting alternative tfrp server.

Please let us know 

Regards

Carlo

[Ibrahim AlQumairi]

To potentially resolve this issue, consider resetting the security settings from the phone administration tab. This action will clear the phone's certificates and may provide a solution.

[bryg0d]

Hi Ibrahim,

Already tried to reset the phone multiple times but still unregistered. Any other work around?

[alightmotionzone]

Hi, 

The issue of a phone becoming unprovisioned and unregistered despite reconfiguring with the same settings, including the DN, and obtaining the correct IP from the voice VLAN DHCP pool, might need further troubleshooting. Ensure that the device is connected to the correct network and that there are no issues with the network connection or configurations. If the problem persists, contacting your system administrator or IT support for detailed diagnostics and resolution steps might be necessary.

Thanks 

[Francisnuel]

It abruptly went Unprovisioned and appeared unregistered in Cisco Unified Communications Manager (CUCM). After attempts to resolve the issue by deleting and re-adding the phone with the same Directory Number (DN) and configurations, it stubbornly remained unregistered. Network connectivity has been validated, DHCP settings are correct, and the TFTP server seems accessible.

[Leo Laohoo]

Another thing to consider is someone has stood up a rogue DHCP server in the network.

[bryg0d]

Hi Francisnuel,

What I did was I disabled DHCP on the IP Phone then manually adding TFTP Server on the IP Phone. You also can add DHCP Option 150 on your DHCP Server and put your TFTP Address. Try this steps and let me

know if it works or not.