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Upgrade / Downgrade firmware of specific IP Phone


Following document explains how to upgrade or downgrade the firmware of an IP phone without disrupting customers production system.

We need to follow a couple of  easy steps to accomplish this, its valid for CUCM 5.X and above.

Hope you find it useful.

1- Download the ZIP file of the firmware on


2- Extract the ZIP into a folder for easy upload to the CUCM.

3- Go to the OS Administration page of the CUCM and upload the files manually one by one, make sure the directory is blank that means

that will upload it to the root of the tftp.


4- After you upload all the files of the folder, copy the file name that ends with .loads.


5- Now you can paste the name on the phone load name field of the target phone, under CM Administration --- Device --- Phone,  section.


6- After this you will have to reset the Cisco TFTP service under the Serviceability section of CUCM, which will not cause any phone to unregister or anything like that, tftp service its in charge to serve FW files, configuration files, background images for example.


7- After this you will have to reset the phone, in this way the phone will request the new configuration file with the load name

it has to request everytime it registers.

Hope this helps.



I have followed same procedure but no luck.


Still my 7942 phone with old firmware version.


Any idea plz. 

Cisco Employee

Hi maheshgunaratne,

Whats the current version running on phone. Is it lower to 8.3.3.

Which FW version are you trying to install.

Can you confirm complete UCM Version

Please note :

For all SCCP firmware upgrades from firmware release versions earlier than 8.3(3) to Version 9.3(1) or later, you must first upgrade your phone firmware to an intermediate version (8.3(3) to 8.5(2)) and then upgrade to 9.3(1).

Make your meeting this pre-checklist before upgrade.


Please rate if you this post helpful. 





Mohammed Noor




current version  (7942 phone) - SCCP42.9-0-3S

New version in device default - SCCP42.9-3-1SR4-1S

cucm version -




Cisco Employee



You need the device pack for your CUCM to install 9.3


For Cisco Unified CallManager 4.2 and earlier, these device packs are required. For Cisco Unified CallManager 4.3 and Cisco Unified Communications Manager6.0 and later, you must run the device pack and reboot the Cisco Unified Communications Manager server.




Thanks for the comment.

I will try and let you know.


I am trying to update firmware in my 7975 phone. I have two TFTP servers in my cluster, one in the pub and another in a sub. However, when I point my phone to the tftp server running in pub, the upgrades succeeds. However, pointing the phone to the tftp running in sub results in error. Any idea why so. Also I have following questions:

1. Do I have to upload the firmware in both tftp servers or just one?

2. What is the difference between FTPing vs uploading through tftp management within OS admin?

Your guide misses a few very crucial steps that could cause huge problems if someone finds this guide and doesn't do the proper research on their own. I would remove steps 2 and 3 from your guide and replace with this:

1. First, read the release documents for the firmware.  There may be compatibility issues or a required .cop file for the updated firmware to function.

2. Before you upload any phone firmware go to Device Defaults section under Device->Device Settings->Device Defaults.  Write down the CURRENT Load Information for the device you plan to upgrade.  Make sure you have this copied exactly (paste it into notepad).  I would highly recommend upgrading only one phone firmware type at a time to prevent confusion or oversight.

3. Once you install the new firmware files via TFTP (and cop files via SFTP), go back to CM Administration and check the Device Defaults section under Device->Device Settings->Device Defaults.  The Load Information will have been automatically updated to the new firmware version you just uploaded.  This is NOT what you want if you are planning on updating only one phone to test first.

4. Replace the Load Information with the previously copied original Load Information from step 1.  This will prevent ALL phones of that model type from pulling the new firmware when you re-start TFTP.  Save the Device Defaults page.  The Publisher node will sync this information with the Subscriber nodes automatically.  Exit and reenter CM Administration and double-check Device Defaults saved correctly with the original Load Information.  If so, then you should proceed with resetting the TFTP service on the Publisher and then all Subscriber nodes.

Hi Richard. I may be wrong, as I'm saying this off the top of my mind, but the method depicted above is simply uploading files to the TFTP, which doesn't change the device defaults on the database.

The device defaults ARE changed when a device pack is installed on the CUCM, but that is a different procedure.

Device defaults are changed when you upload new firmware and .cop files.

The guide here is for updating the firmware on one phone, he left out steps that would otherwise update all phones of the specified model if TFTP was restarted.

Cisco Employee

Hi Richard,

With this process the device defaults never change.

The only way the will change is if you use cop file installation.

We have done this many times and if you upload files and tftp no changes are going to be done after you reset TFTP.

If that is happening to you the RCA should be something different and I will suggest opening a TAC case.

Hope that helps.

Antonio Taylor


Hello, I am tryng to upgrade the firmware on one of our Cisco 8831 conference phones. I downloaded the files and uploaded them to our 2 TFTP servers and restarted the tftp service but the new firmware will not load.

We have an 11 server cluster. Do I need to upload the files tot he rest of the servers in the cluster as well?

Thank you,

Rob G


Antonio writes upload the files manually one by one. Does this include term42.default.loads and term62.default.loads ?

I have followed this procedure uploading all .sbn and .loads files apart from the two mentioned above. My 7942 upgraded without any issues. 

Would uploading the .default files change default loads for all 7942/62 managed by our CM? Would this then trigger update after phones are restarted?




Any advice on how to do this with the 8851 series phones. I'be done this many times successfully in the past on 79XX phones (and yes, your statements above are 100% correct). 

My problem with the 8851 phones is there is a different section called "Dual Bank Information" and it doesn't look the same as the 79XX. There's just "Load Information" and "Inactive Load Information".

I want to download the latest firmware and just apply it to a single phone, using it's "Phone Load Name" at the device level, like what is described above. There is no way to paste the old firmware version in the "Load Information" section.

Screenshot attached.


joshua.gertig "Any advice on how to do this with the 8851 series phones. I'be done this many times successfully in the past on 79XX phones (and yes, your statements above are 100% correct). " I agreed w/ your statement. I have successfully updated (sip88xx.12-0-1SR1-1) to a specific CP-8851 phone after TFTP server had restarted. 

Thanks Antonio Taylor.


Not working on 8845 with CUCM System version: All the directions go smoothly; but after I reset the phone, the active load does not change to what is in Phone Load Name field. Any help would be greatly appreciated!