For a start I used a free softphone (I don't want to name it) with poor voice quality and I got totally fed up with it so I decided to change it for a better one. I tested and then purchased Ozeki VoIP SIP SDK and the video and voice quality seems to be all right with it (sample p.: http://www.voip-sip-sdk.com/p_357-video-quality-resolution-codec-voip.html ). It supports many codecs and is compatible with lots of open source pbxes like Asterisk. Have you got similar experiences ? Any bad points?