2921 CME Upgrade to support 8821

[mumbles202]

Currently have a 2921 running 9.1 with a handful of 7925 phones running that access a service url that runs on the router.  As the 7925s aren't available anymore plan to deploy 8821's as well.  Do i just need to upgrade to either 10.5 (define the devices using Fast Track) or upgrade to 11.x to gain full support?  I realize either will require upgrading the IOS on the router.  I haven't used Fast Track before; if i go that route can i define this:

voice register pool-type 8821
xml-config maxNumCalls 6
xml-config busyTrigger 6
num-lines 114
description Cisco IP Phone 8821
reference-pooltype 9971

and then define the ephone as normal?  

[j.huizinga]

I have used fast track several times, and in general it works fine. So you can try this, but the 8831 is a SIP phone, so you have to add SIP configuration, not ephone

JH