Chapter 1. Traditional Phone Systems

Before we get into broadband phone services, it is helpful to spend a few minutes understanding the traditional telephone system, known as the public switched telephone network (PSTN). The public telephone system has been in place in some parts of the world for over 100 years and has remained relatively unchanged in principle over most of its existence. Remarkably, even though the underlying technology has evolved several times, the same telephones that your parents or grandparents had when they grew up still work with the phone system today.

It’s easy to overlook how amazing and reliable the public telephone system is. When you pick up a phone, you expect to hear a dial tone, much the same way that you expect ...

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