Why did v14 to v14 SU1 upgrade revert phone firmware?

[RITR]

We were running sip88xx.14-1-1 and after the CUCM v14 SU1 update, it set sip88xx.14-0-1 as the active load. This caused the phones to downgrade. Do I have to install the updated phone firmware again to the inactive partition before switching? Does not seem to match up with documentation.

[Roger Kallberg · Accepted solution]

The versions of phone firmware included in the SU release is listed in the release notes.

What you’d need to do is before the upgrade save the values of all firmware prior to the upgrade and then after the switch version to activate the upgraded version you’ll need to modify any altered values on the device defaults page to put it back to the values previously saved.

To do an upgrade without the phones downloading any older firmware version(s) the recommendation is to before you commence with the upgrade you temporarily set the TFTP service as deactivated on all your nodes that is running it and the after you have completed the steps outlined above you activate it again. This way you should not have any problems with phones downgrading to an earlier version of the firmware.

[RITR]

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@Roger Kallberg wrote:

To do an upgrade without the phones downloading any older firmware version ... set the TFTP service as deactivated on all your nodes ... after completed the steps outlined ... activate it again.

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Thanks for sharing. That's incredible the upgrade doesn't automatically handle this. An upgrade should never downgrade anything. That bit should be in the documentation in between the current Step 9 & Step 10.

[Roger Kallberg]

For your reference this is the information that I refereed to earlier.

As seen it clearly states that version 14-0-1-0201-171 is included in the SU.

[RITR]

It's not surprising that a system update that came out before the latest phone firmware was released had old phone firmware. It is surprising that it ignored the updated firmware that was already installed in the system. Plus, it's not like it didn't know about it because the new firmware was just moved to the inactive slot. Super odd behavior.

[Roger Kallberg]

Can agree that it is not the best and nimblest way to handle this. But that's how it has always behaved. Hence the whole process that I described earlier has been concocted to stop phones from downgrading.