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CUCM 14
Monday, December 26, 2022

Upgrade to CUCM 14SU2 from 12.5


We are sharing our experience in upgrading to CUCM 14. We had encountered some issues and hope that going through this may help others avoid these.

As always, read the release notes for the new version and confirm all the prerequisites are fulfilled. Go through all new features and changes from the previous version to ensure you don’t have a surprise of our life after upgrade. Go through the compatibility matrix and ensure you are on required versions for other UC components and upgrade if not on the recommended version:

Compatibility Matrix

Let’s start with our experience. We upgraded CER followed by an upgrade to CUC pair prior to upgrading CUCM to 14SU2. CUC and CER upgrade to 14SU2 was straightforward and no different experience than any previous upgrade. CUCM upgrade was, however, a totally different experience. Most of this was related to the new cluster-wise upgrade that 12.5 includes. Our MGCP voice gateways were already of the recommended version, so we had nothing to worry about this part.

We upgrade all phones prior to the upgrade to make this process a little easy.

Main guiding document we used:

CUCM Upgrade Guide

  1. Run ciscocm.enable-sha512sum-2021-signing-key-v1.0.cop.sgn on all nodes if not done already.
  2. Run pre-upgrade COP file on all the nodes starting with Pub node followed by all SUB nodes. PUB node had space issues, and we used ciscocm.free_common_space_v1.9.k4.cop.sha512 to free up some space. This cleans up the space but will delete the inactive version which was not an issue with this.
  3. Now start the upgrade using the cluster-wide upgrade option (new in CUCM 12.5) - utils system upgrade cluster initiate.

This was the command line response:

Processing the cluster wide download...

CUCMPUB Processing download request

CUCMSUB Processing download request

CUCMPUB Downloading..0Mb of 4407Mb

CUCMSUB Downloading..966Mb of 4407Mb

CUCMPUB Downloading..3983Mb of 4407Mb

CUCMSUB Checksumming the file...

CUCMPUB Checksumming the file...

CUCMSUB Checksumming the file...

CUCMPUB Download complete

CUCMSUB Download complete


Cluster wide Download complete and Install started

Node                            Role             Step   Description                Historical Time       Elapsed Time                                
----                            ----             ----   -----------                ----------------      ------------
CMPUB                       CUCM Publisher                              9/22                       ucplatformInstall                 

CMSUB                       CUCM Subscriber                            11/22           ucplatform_saml_ssoInstal      

Cluster                         -   Overall cluster progress   03:37:14      



Node                            Role             Step   Description                Historical Time       Elapsed Time  
----                            ----             ----   -----------                ----------------      ------------
CMPUB                                  CUCM Publisher   -      started                    -                     -             

CMSUB                                 CUCM Subscriber  -      started                    -                     -             

Cluster                         -                -      Overall cluster progress   -                     -            




Node                            Role             Step   Description                Historical Time       Elapsed Time                                        
----                            ----             ----   -----------                ----------------      ------------
CMPUB               CUCM Publisher   3/22   setup                      00:01:15              00:01:19      

CMSUBT             CUCM Subscriber  4/22   verify                     00:00:47              00:00:02      

Cluster                         -                -      Overall cluster progress   03:37:14              00:01:22  

This didn’t work for us very well. It took about 30 min to just fail on us indicating it failed to download on sub nodes. Don’t panic if this happens to you too. Just cancel the upgrade on each node (starting with PUB) using utils system upgrade cancel. Reboot all nodes and do the old fashion way – upgrade individual nodes starting with PUB. This is the only issue we hit during upgrade.

  1. Once you have upgraded all nodes, its time to switch version. Do this on PUB, wait for all service to come back up and do SUB nodes in a way that works for you. We did in groups to not lose phones at any time using failover CM group
  2. Now, its time to do post upgrade COP file, check enterprise params and other system settings as they might have changed during upgrade like TFTP serving settings
  3. Upgrade took 3 hrs for PUB upgrade, 2 hours for SUB node. Switch version was really fast as compared to previous versions- 10 to 15 min