[rupertdev]

What protocol does this actually use for VoIP? I do VoIP over ham radio with various protocols, I'm curious what this uses behind the scenes and didn't see in the docs.

[laksdjf]

Took me some time to figure out how this works. The webpage is mostly about the hardware.

Here are some old screenshots (2018). You basically enter your own SIP account to call

https://www.wiphone.io/blog/2018-08-17_-_GUI_Screenshots.htm...

[jqpabc123]

See the documentation. They are using a number of "free" SIP providers. You can get the details from them.