Anyone has done this b4. I have a 'live' callmanager with 1000 phones. need to upgrade to the above version. Objective is to allow the usage of the 7971 phones.
I believe upgrading directly to either version CCM4.0(2a)SR2a, SR2b or SR2c should not made a difference to installation procedures. The Publisher will be taken offline 1st and upgraded. Then remove subscriber and upgrade, at the same time, publisher will join the network. As all the 1000 phones will tftp to new version of ccm to get the new firmwares. Will there be any issues like congestion, phone unable to upgrade and etc.
In any case if upgrade failed, as our servers are running on raid, hence we will retain the harddisk which is the mirror image b4 the upgrade. If we fall back on the old one, will phones that are already register to the new callmanager version able to register to the orginal version because there will be a downgrade of firmware. I heard that firmware cannnot be downgraded.
Also i have a xml script running on publisher to allow end users to login to phone using PC. will the upgrade affect the script.
Pls assist. thanks alot.