Explore the evolution of VoIP technology

Telephony evolved, since the early 1900s, from analog systems to digital to today's unified communications and enterprise voice over IP, or VoIP technology, advancing to support business growth and greater efficiency. To understand today's options in communication systems, it helps to know how it all began.

The first business telephone systems -- private branch exchanges, or PBXs -- used analog networks to send and receive voice signals as electronic pulses over a wire.

Digital PBX platforms, which used the underlying telephony cabling but supported more calls by converting voice signals to a binary format, came next. More efficient transport allowed more calls to be made and received on physical copper or fiber-optic trunk lines. Digital PBX also provided a crisper sound with less static and ushered in features like voicemail, three-way calling and conference dial-in capabilities.

But digital PBX deployments yielded to the rise of the internet. Businesses deployed data networks built on Internet Protocol (IP) to let employees access the internet from their desks. But this meant maintaining two separate networks -- for digital voice and for data.

That's when vendors developed digital voice systems to operate on the same IP networks as computers. Voila: VoIP technology was born.