It's sent as plaintext and as a query string parameter. I'm not aware of any other way - but I'm sure with the move to https, we'll see https support for phones sooner rather than later - I guess the biggest challenge is certificates since you can't just accept a certificate on the phone as you'd do in a webbrowser.
In the meantime, I'd rely on separate VLANs and port authentication on the switch to ensure nobody hook in between the phone and the switch to get the traffic - and if you have untrustworthy individuals having access to the backbone of your network, you have a whole set of different problems that encryption of ip phone services won't cure.
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 ...