I haven't tested this one, but I have tested another one that also optimizes for satellite. You can go to Sun-ISP.com for details or go to our web page for some info:
http://www.mobileinternetsatellite.com/ ... pandable=3Since they have a money-back guarantee, you could just go ahead and give it a try.
Or, give Sun-ISP a try, for no investment if you go with a Soft Phone or a minimal one otherwise.
The voice-quality for VoIP over Satellite will never be toll-quality but, I've definitely experienced the major difference it can make, when a VoIP provider optimizes for satellite.