In my case I was troubleshooting a customer's 7975 using the same FW and CUCM Version as you did.
The problem was the disabled web server on the IP phone. Once I changed this, everything worked fine (didn't find any application note why this needs to be enabled, though).
Can you have the firewall checked for dropped connections between the IP phone, the Phone Designer Application and the CUCM? The log in the Program Files Folder is quite verbose and might direct you to the right direction.
You have reached the Cisco Logistics Support Center.. To Check Status of
your RMA, visit Product Returns & Replacements (RMA). Need help? Contact
us by Phone or Email. North Americas Phone: 1800 553 2447 Option 4
Email: firstname.lastname@example.org Europe Phone: +3...
The short answer is that you don't.... That isn't entirely true while at
the same time it kind of is, but for the most part you don't configure
the softkeys. You enable or disable them via TCL. Here is the long
answer. Be sure to read the whole thing or e...
Topology: IP Phone > Switches > Microsoft NPS setup to forward 802.1x
proxy to > ISE 2.1 patch 3 Authentication: EAP-TLS using Cisco MIC SANs
Phone Models 802.1X support? 802.1x flavor Addtl Comment EAP-MD5 EAP-TLS
Cisco 3905 Y Y N Cisco 6911 Y Y N Cisco ...