Ever since Alexander Graham Bell heard the first sound over a telephone wire, technology has raced ahead to make communicating over long distances faster, easier and less expensive. Voice over Internet Protocol (VoIP), or the transmission of data over a computer network, can be used to transmit different types of data, but it's rapidly taking the place of public-switched telephone networks, especially in developing countries where regular telephone service may not be available, or is too expensive for many people to afford. The number of VoIP subscribers tripled between 2010 and 2011, and is expected to continue to grow. This infographic from Vopium traces the history of long-distance communication to the present day. We've come a long way, baby!

INFOGRAPHIC: The Global VoIP Revolution

Infographic by Vopium via visual.ly