Looking for CUCM 11.5 -> 12.5 Install Documentation

[coleman.noc]

Hello,

Looking to see if anyone has the documentation to upgrade CUCM from version 11.5 -> 12.5. 

I'm only able to find documentation to upgrade to 14.

Thank you,

[Jaime Valencia]

There is no specific documentation for each upgrade path, the documentation for the target version is the one that has to be reviewed.

Mandatory reading regardless of what upgrade path you choose, all for target version 
 
A) Upgrade and migration guide
B) Release Notes 
C) Compatibility matrix (depending on product might be a standalone doc, or within any of the other docs I mention) 
D) README from ova
E) HW/ESXi compatibility 
 
After reading all of the above, you'll have all the information to plan the upgrade. 

Go to Cisco.com
Click on Support
Product Support column -> View all product support
Choose applicable option, Unified Communications in this case
Search applicable product, Unified Communications Manager in this case
And you're in the product documentation.

[Nithin Eluvathingal]

Here is the guide which you are looking for.

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/upgrade/12_5_1/cucm_b_upgrade-migration-guide-125x/cucm_b_upgrade-guide-1251su2_chapter_00.html

Apart from the above guide Before upgrading,  Read all guides which JAVA mentioned