Chapter 5. WebRTC Integration with PSTN

The Voice over Internet Protocol (VoIP) telephony is one of the coolest things ever invented. It gives us the ability to use the power of Internet in the context of communication such as user discovery; user presence; virtual conferences; file sharing; notifications based on web feeds such as news updates, parental control, and IPTV / Video On Demand; extensive option of call control; and, most importantly, the ability to take our call from any place where there is IP connectivity. However, what if there is no IP connectivity? What if there is just a fixed cable connection that supplies analog outputs?

There are still many such analog connections (called Public Switched Telephone Network (PSTN) endpoints) in the world even today that only have a dialer as the user interface and a handle with an embedded speaker and microphone.

As WebRTC is not intended to be just a web-only communication tool but to also connect to all other devices capable...