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Question about phone firmware CUCM 8.5.1


I have a pretty simple question that I can't seem to find the answer to in my docs. We are currently running two different versions of firmware on our 7965 (skinny) phones. Our device default, used by 80% of phones is SCCP45.9-1-1SR1S. The other 20% or so are using the latest, SCCP45.9-2-3S.

We are planning to upgrade to the latest CUCM Version, in the next couple of weeks. I've read that that version comes with firmware version 9-2-1.

I'd like to install that version make sure that firmware is stable, particularly in our call center before we upgrade CUCM.

Are there any limitations in terms of how many firmwares you can have running at one time (in my case, it would be 3)?

Also, does anyone know if the latest version I currently am using (SCCP45.9-2-3S) on the 20% of phones will carry forward after the upgrade? The phone load for those 20% are configured on the device level of each phone (as it's not the device default).



Hall of Fame Super Silver

Question about phone firmware CUCM 8.5.1


No, there are no limitations, you can have every phone on different version if you wanted to :-)


Question about phone firmware CUCM 8.5.1

Chris is correct with the obvious caveats around feature compatibility.

In regards to your second question, I am not sure about the installer but in my experience there have been upgrades that will reset the device defaults to the version of firmware they come shipped with. This can be problematic and should be accounted for in your upgrade plan.

How I would approach your situation is as follows:

1. I would check the 9.1.1SR1 firmware compatibility with the new UCM release.

2. If upgrading firmware, I would lean to the 9.2.3S (or latest SR of that release) and I would push that out to phones in advance of the UCM upgrade.

3. To avoid accidental firmware upgrades, I would use BAT (or similar method like AXL/SOAP, SQL Update, etc.) to hard code phones to the exact version you want them to run. THEN do the UCM upgrade and THEN move the phones back to where they were prior to the upgrade.

This last step may inspire disagreement, but here is my logic - the goal is to minimize disruption (especially unexpected disruption). I had an upgrade a few years ago where the customer neglected to address the potential accidental firmware upgrade and they were freaked when 90% of their phones started upgrading firmware across their WAN links.




HTH -Bill (b) (t) @ucguerrilla

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Hall of Fame Super Red

Question about phone firmware CUCM 8.5.1

Hi Josh,

I'll add my vote to the good info from Chris here (+5 "C-Man")

We had 5 different 7945/65 firmware versions running @ one point during a Pilot testing

phase so you should be good to go here

Your phones that are running 9-2-3S will move across with that same firmware after

the upgrade.



Community Member

Question about phone firmware CUCM 8.5.1

You guys are awesome, thanks for the help and advice!

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