IP Phone freezes and becomes unregistered

[kfbaluyut17]

Hi All!

I have a problem with 1 Cisco 6941 IP Phone. The phone intermittently freezes and upon checking in CUCM, it becomes unregistered. Sometimes I can also see the phone in "Network Unavailable" state.. Then I just unplug and plug back the IP Phone and becomes working again. But it happens on a daily basis and is only happening on this specific phone. Already isolated and it is not a network issue since other phones are not having problems in the same port.

We are running on CUCM 10.5 and firmware of all the 6941 IP phones are SCCP69xx.9-4-1-3SR2. I already set debugging level on all the options available in the IP Phone>Settings>Admin>Debug IP Phone but I cant find anything that can lead to the root cause of this. I'm suspecting this is a hardware issue but I do not have any evidence yet.

Hope someone can help.

Thank you!!

Kenneth

[Manish Gogna · Accepted solution]

Hi Kenneth,

Since you have already done the isolation bit by trying other phones on this port the issue would be specific to this phone. A few things that you may try before you involve TAC or RMA the phone:

>> delete and readd the phone on cucm

>> try registering it to a different cucm server in the cluster if possible

>> try a different firmware than existing one and see if that helps

>> try a factory reset of the IP phone

Manish

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[kfbaluyut17]

Hi Manish,

I will try all your suggestions and come back to you if any of those will work. This will take some time as we do not know when the issue will exactly happen and what triggers it to freeze.

Thank you so much!

[Manish Gogna]

Sure, do let us know the outcome.

Manish

[kfbaluyut17]

Hi Manish,

I've tried all your suggestions but none of them worked. the phone keeps freezing after some time. No need to involve TAC since the phone is not under RMA. 

Thanks for the support. :)

[Alan Brown]

Curious if you were able to find a resolution to Cisco IP Phone freezing and dropping registration to CUCM. I'm experiencing the same problem with Cisco 8845 phones connected to CUCM 10.5(X) and now 11.5.1, have received ES firmware for the phones from TAC but did not resolve the problem.

[Alan Brown]

Hi Kenneth, were you able to resolve the problems with Cisco IP Phones freezing and dropping registration? We are having a similar issue with 8845 phones connected to CUCM 11.5.(1).

[spricker]

Is the problem fixed, we are facing the same issue with 8845 Phones and CUCM Version 11.5 SU5

[rmarx@nwnit.com]

CUCM 11.5.1 su7 and 8841 (firmware 12.7..) freezing up with incoming call.

Did anyone find a root cause of this ?