In this blog

ATC Insight

More details about the ask

As part of the initial Proof of Concept (POC) testing environment that was built, the customer requested a fresh install of CUCM version 12.5.1su2. As testing started to occur, another request was put in to have those clusters upgraded to su3 without affecting the testing timeline. Challenge accepted!

New enhancement

Pervious to CUCM 12.5, when an organization needed to install a service release, the procedure required you to log into each individual application to perform the required task.

The new enhancement in CUCM 12.5 allows you to perform that procedure from one web interface, the primary (publisher) node of the cluster. This allows you to install, upgrade, and switch versions for the cluster using a more controlled and structured method which saves time and is more efficient.


In this documentation section, we provide an overview and step-by-step instruction for a new Cisco Callmanager feature in 12.5 that enhances the Install/Upgrade/Switch Version functionality within the Cisco Unified Communication Manager (CUCM) application.

The below step-by-step instruction demonstrates a service release upgrade for a 3 node CUCM cluster and a 1 node IMP cluster. We will upgrade from 12.5.1su2 to 12.5.1su3 for both applications.

Video of Step-By-Step with Commentary

Attached to this documentation below is an MP4 video provided by ATC Lab Services collaboration architect Kallol Khan.  In this video, Kallol gives some insight and commentary around the step-by-step process which is highlighted below. Check it out!

Step-By-Step Process of the enhanced upgrade in 12.5

 1. Log into Cisco Unified Operating System Administration from Cisco Unified Commutation Manager. 

2. Select Software Upgrades → Install/Upgrade Cluster.

3. Under Software Location, set the correct path to the SFTP server. Also, make sure under Upgrade Options that continue with upgrade after the download is unchecked. This will allow you to check to MD5 hash before proceeding with the upgrade. Select Next.

4. In our example, we will be installing a service release for both CUCM and IMP. Do note the IMP Publisher will need to have the same software location path as the CUCM Publisher. CUCM and IMP will have different file names as they are different applications. Choose the correct upgrade file. Select Next.

5. You will notice that all nodes in the cluster will be listed and that the download process will start.

6. Depending on the size of the file and number of nodes, the download process will vary. One thing you will notice is the percentage of the file downloaded.

7. Once the download is complete, you will be able to verify the File Checksum Detail and Version Options for all files that were downloaded. Please leave switch-version cluster after upgrade unchecked. Select Next.

8. At this point, you will see what step in the install process you are at and the estimated time to completion.

9. As the installation occurs, the webpage may timeout and log you out. Please log back in to check the status of the install. Do note, you will reach a step in the install that the other nodes will be waiting for the CUCM Publisher to finish before they continue.

10. Once the CUCM Publisher states Upgrade complete, the other nodes will continue to databaseInstall in the Description column. 

11. Once all nodes states Upgrade Complete, please proceed to Software Upgrades → Restart/Switch-Version Cluster.

12. This step will allow you to switch versions from one interface for all nodes in the cluster. You will be able to set the order of the switch version and verify the status of the switch version. Do note when the switch version occurs on the CUCM Publisher you will get a timeout of the web interface and will need to log back in about 10 minutes. Select SwitchVersion for the process to occur.

13. Once the switch version is complete for the CUCM Publisher and IMP Publisher, you will get the Active and Inactive version of the software that is running. This also a check to verify that the upgrade software (in this example, the service release) is installed.