I want to upgrade my current VoIP configuration of a SPA9000/SPA400 with a UC520-8U-4FXO-K9. I am using SPA921 phones, are they compatible with the UC520? How difficult is the setup for the UC520, the SPA9000 was very simple and easy to use.
I can't remember if these phones can run SCCP (I don't think they can) so in that case you'd need to run SIP CME. CCA doesn't do that outside of the box, but if you're okay with administering the box from the CLI, you can make it happen. It just won't be TAC supported, since we only support SIP CME to Cisco IP phones (which the SPA900 Linkysys phones aren't a part of, technically).
If I understand correctly: The SPA921 phones can be used with the UC520 but I need to run SIP CME, but the Cisco Config Assist doesn't support that configuration. I would have to admininster the UC520 from the command line to set it up. Does that apply to the SPA921 as well, they would have to be individually managed?
It is always better to administer using CLI. Other means do not produce good results or no results at all.
Although I agree that I personally prefer the CLI too, using the CLI over CCA for the UC5XX products is a very slippery slope if you want TAC support. Those products were designed around configuration via the CCA GUI.
Configure Multicast Paging on the Cisco IP Phone 7800 Series or 8800 Series Multiplatform Phone
The Cisco IP Phone 7800 and 8800 Series Multiplatform Phones provide voice communication over an Internet Protocol (IP) network...
Add Call Park on a Cisco 7800 or 8800 Series Multiplatform Phone Key Expansion Module
Call park allows the user of the phone to put an incoming call on hold so that the call can be retrieved on another phone. A call is park...