Could you please help me with a such question.
I've installed a new CUCM server ver. 12 and want to upload backup from my old server ver. 10.5.
Is it possible or I need to upgrade my old server from 10.5 to 12 and then make backup and upload it on a new server?
Does my backup file contain such information as ip address, hostname, certificates, administration users, security password? Could it change this parameters on my new server after backup upload?
A restore will only work on the exact same version from which it was taken.
The DRS guide explains the procedure, and what information needs to match for a backup to be restored, review the online documentation.
Yes, you can change whatever you want after you restore.