You can probably do an IP address call. I would assume that your devices both support direct IP calling. The voice traffic then never leaves your network.
However, there is no voicemail fallback in this situation.

The IP Address call that you suggest works fine, but as you say, it is not easy to get voicemail fallback using that technique, hence my search for a new one.

Just curious if anyone has got the reinvites to work properly with their service provider?

I am having similar problems where I have the nasty triangle I am trying to get rid of. I'm using callcentric and perhaps they don't allow reINVITES -- I'm waiting for a response from them to see...

If you HAVE got reINVITES working -- what provider are you using? This will help us all out!

I'm still having problem trying to bypass voxalot proxy. I'm also having this triangle issue. I'm using Outpost Firewall to monitor my network activity and it's showing that incoming data goes directly to my VSP while outgoing data passes through voxalot proxy first.

Curiously, using MySIPSwitch without any STUN server and behind an NAT, I was able to bypass their proxy with no problem.

MySIPSwitch does not handle the media stream. It deals only with SIP Signaling.

I too had the triangle (or three legged) call problem. It happened last year whenever I used VoipDiscount through Voxalot. I have not recently checked for the problem.

What happens if the "Hold" button is NOT pressed at all? I assume the call still go trough with audio NOT bypassing Voxalot. Correct?

So if pressing the "Hold" button twice indeed causes the audio to bypass Voxalot, can such pressing be postponed a few seconds after the call is answered?