Upgrading whole VOIP phone system to 12.5.1 from 11.5

[rogalskij]

A little later in April, I am planning to upgrade both Cisco Call Manager and Cisco Unity to version 12.5.1 from our current version of 11.5.1.13902-2 which we upgraded to in 2016 or so.  I am curious if anyone has any recommendations about doing this?  I will of course read the release notes and upgrade instructions, but I wanted to get a sense of how the upgrade will look, if it is major or minor in terms of features and interface changes. 

When we upgraded from 8.6 to 10.5 we needed to change the virtual machine specs, will we need to do this from 11.5 to 12.5.1? 

We looked up the depreciated phone list for 12.5.1, but couldn't find any information on 12.0 itself, is this the same list?

Again, I am not looking to circumvent reading the upgrade suggestions, just hoping those who went through this already could give me some tips.  I am not the phone admin, but I assist in the server upgrades and I wanted to be proactive for my institution.  Thank you for absolutely anything you can suggest.

[Jaime Valencia]

I applaud that you're going to read the documentation for this, but that should have been your first step prior to posting, as many of the things you're asking, are already covered in the documentation.

New features and changes to the interface are covered in the RNs.

New deprecated phones on 12.5, also covered in the RNs

To know if you need to adjust the VM specs, you compare the OVAs in the virtualization wiki. At the very least, the VM HW will need to be upgraded (if you haven't done so already)

You also need to add to your reading list the 12.5 OVA README, along with the upgrade guide and RNs

[rogalskij]

Totally understand and agreed Jaime, but the thing is I was more looking for someone to jump in and say "hey, this thing happens when you are upgrading that you should really know about, it isn't directly covered in the release notes or upgrade guide.  More looking for those tangential things.  If anyone has any of those I would greatly appreciate those sort of insights.

Promise I will read though. 

[leonardjam1]

Hello Rogalskij,

We're in that place right now, upgrading from 11.5 SU4 to 12.5 SU1, were you successful in your upgrade? Did it go well?  anything unexpected that was outside of the Cisco documentation? Any other recommendations?

[rogalskij]

Hello Leonardjam1, we did fairly well when we upgraded besides a major bug that has since been fixed. A few things that I can recall from the upgrade are as follows. I am sure every situation will be different, but our situation was:

Upgrading Call Manager, Unity, and Attendant Console to 12.5.1 (12.0.1 for Attendant Console).

First off, I highly recommend reading through the tedious upgrade notes. They do very much help you understand the upgrade but you will likely die of boredom. When we upgraded, we had 1 mobile phone model that was no longer supported and wouldn't function that we had to replace, all the rest of our VoIP phones still had support but I recommend you look at that so you don't accidentally brick 200 older phone models. We had to up the ram and CPU on our virtual machines. This was important since our virtual machine templates were older from 8.6 or whatever it was and didn't have the same stats a modern virtual appliance would.
Additionally we found that the upgrades took a really long time. We have a publisher and subscriber and you do the publisher first. It took several hours to do each. We did Call Manager first. We had a couple things that were out of place, like licensing, we had to work with Cisco to get our existing licenses converted to 12.5.1 licenses, this took forever for some odd reason and was more complex than it should have been. Also when we upgraded we had some certificates that were busted, and needed to be replaced, Cisco TAC helped us with that. The big big issue we experienced was the DHCP bug (CSCvp46990) that affected the initial version of 12.5.1 which was 12.5(1.10000.22), we originally used DHCP inside of Call Manager, and with the newest version there was a bug that broke DHCP entirely. Most of our phones stopped getting IP addresses and it took us a bit to figure it out. We temporarily switched our DHCP to our main dhcp server and all things went correct again. We have since installed an updated version where DHCP is fixed (version 12.5.1.11900-146) but we opted to stay with our external DHCP server for parity sake.
Those were the quirks and how ours ended up. I recommend downloading the latest build of 12.5.1 as it will likely do much better than our initial build. The version we are on now fixed a TON of issues our phone admin was seeing (especially with the low end 3905 classroom wall phones we use). Hope this helps and best of luck!

[leonardjam1]

Super Helpful! Thank you, my team is on their 3rd read through of all the upgrade docs and we're lucky to roll this out on a lab environment first..starts tomorrow. Really appreciate the feedback.

[nirajsomaiya]

We are planning this for one of our client and i was looking for some similar experience tales. Just one question, while doing 1st publisher upgrade , the phone which are registered on subscribers remains working (like normal voice calls). or do they de-register.? 

We have 4 subscribers with 5000+ ip phones (with 2 TFTP), so trying to understand the downtime w.r.t IP phones availability to users during the upgrade starting from publisher.

Upgrade guide doesn't have much clarity on this. So trying to understand downtime required for upgrades and when phones will be up and running..

Thanks in Advance ...

[Roger Kallberg]

Upgrade of the publisher will not affect phone registration to subscribers.