I'm doing WS100 p4 to P4. I'm trying to connect the two WS100's to each other accross the public internet. It works partially (ringing happens), but I don't get a voice path. (It works fine 'internally'). I connected one P4 to my PBX, and created a 'hotline' on it that when an IP call comes in, it seizes an port on the PBX and dialls the remote access code. So, I don't have 'true' extension dialling, but it will work for the most part.