Problem with model 8851 phones

[hammond]

Three of the five Model 8851 Cisco VoIP phones in one of our administration departments at our University started to experience a problem. This started around August 21, 2024. Previous to that, no problems. 

The problem is these three VoIP phones will randomly re-boot when on a call. The person is on-hold when the phone comes back up. A user stated she noticed this occurred more frequently when putting an in-coming call on hold.

Any suggestions why this is happening?

I did look at the forums and there was a problem reported very similar to this that had to do with a firmware update which was installed around this time, but no solution was given.

[Wayne DeNardi]

You mentioned that the issues has occurred following a firmware update - have you tried downgrading a phone to the older version to see if that resolves it, and points to the firmware as the issue?  Or have you tried a newer firmware to see if that helps resolve the problem?

[Leo Laohoo]

---

@hammond wrote:
The problem is these three VoIP phones will randomly re-boot when on a call. The person is on-hold when the phone comes back up. A user stated she noticed this occurred more frequently when putting an in-coming call on hold.

---

Description sounds like the phones have hit a bug and crashes.  

If it is possible to video record this event from happening and pass the recorded video to the people who manages the phone system for troubleshooting.

[hammond]

I do not foresee being able to record it because it happens randomly. It may be fine for 4 or 5 hours, then glitch, and then be fine for a random amount of time.
Also, I am the person who manages the phone system. I have seen it happen. I do not know why it is and that is why I was asking for more learned, experienced peoples knowledge.
We also have a company who assists with the administration of the phone system. When I asked them about this issue, they told me to contact Cisco about it.
How can I enter a work order with Cisco to have them look into and troubleshoot this?
Thank you.
Brian

[Leo Laohoo]

---

@hammond wrote:
A user stated she noticed this occurred more frequently when putting an in-coming call on hold.

---

Could try this and see if it is reproduceable.  

[Matt_W]

You could pull debug information from the phone. This would most likely be more useful then a video for TAC. You can find directions on how to do this here: https://www.cisco.com/c/en/us/support/docs/collaboration-endpoints/ip-phone-8851/218093-configure-debug-level-in-mpp-phones-regi.pdf