I came across this post from Google, and although it's old, it does cover some key concepts that I have seen users struggle with. Providing people with a fully featured WebRTC Phone, rather than a script library was the inspiration for Starting Siperb. Then, also providing people with the tools they need to connect this Phone to any Asterisk box (even and older one) or a hosted one was a natural next step. If you are not up for the challenge of sip.js or sipml5, just head over to https://www.siperb.com/