Prior to the advent of internet interactive communications were only made by telephone at PSTN line cost, which was very expensive especially over long distances. With the advent of highly advanced network technology and computers being massed produced and available to consumers at a lower; people begun to communicate with new services like email, chat, etc. These services were extremely cheap and easy to use but lacked the personal touch provided by telephone. Therefore big corporations began to fiddle with the idea of allowing people to have real-time vocal communication and thus beginning a totally new chapter in internet history: VoIP.

As stated above VoIP stands for Voice over Internet Protocol and is a technology for transmitting ordinary telephone calls over the Internet using packet linked routes. VoIP is also referred to as IP telephony. VoIP involves the transmission of telephone calls over a data network like the Internet. In other words, VoIP can send voice, fax and other information over the Internet, rather than through the (PSTN) or regular telephone network. A major advantage of VOIP and Internet telephony is that it avoids the tolls charged by ordinary telephone service. VoIP telephone calls (voice) bypass the typical public-switched telephone network and transmit voice calls over a private network (the same network that carries web, e-mail and data traffic). In General Voice over Internet Protocol (VoIP) refers to the use of the Internet for making telephone calls. The main advantage for users of VoIP connections is that they generally only have to pay their usual (local) Internet connection charges regardless of where they are calling anywhere in the world. VoIP telephony hence threatens the traditional distance and even time-based pricing model upon which all major voice line telephone services are currently based.

Voice at the Source -> Digitized using ADC -> sent over Internet -> Digitized Data Received at Destination -> Data is reconverted to Voice using DAC.