Some other good sources of information: The 7941G has two line buttons, the 7961G has six.
For services like Cisco Spark Messaging, since it is a cloud-based service these back-end changes will be seamless to users.
I'm using Switchvox Free 1.0 version, but it's WUI only so how do you load the SEP files?
I've turned off natting and I'll test it again when I get back to the office, but I don't have high hopes.
This subject would not be worthy of its own page for most phones, but there are enough caveats and workarounds for these UAs that others may benefit from shared experience.
Note that US part numbers are used throughout this write up.
However, the little phone icon will have a X next to it. EDIT: Now asterisk can see the phone, but it comes up as "UNKNOWN". In that case consider downgrading to previous firmware version.