Voice Over IP, or VOIP, is a group of methodologies, communication protocols, technologies, and transmission techniques which function to deliver voice communications and multimedia sessions over Internet Protocol networks. An example of such Internet Protocol networks is the Internet, a rather famous one. Internet Protocol telephony, broadband telephony, voice over broadband, Internet telephony, and broadband phone are other terms which are often used synonymously with Voice Over Internet Protocol.

Voice, SMS, Voice-messaging applications, and Voice are the communications services that ‘Internet telephony’ refers to. These communications services are transported over the Internet, instead of the public switched telephone network. So how does one go about conducting a Voice Over Internet Protocol telephone call? Basically, one must execute the digitization of the analogue voice signal, media channel setup, encoding, packetization, signalling, and transmission. Similar steps must be taken by the receiving end of the Voice Over Internal Protocol telephone call. The receiving end must receive the Internet Protocol packets, decode the packets, and makes a digital-to-analogue conversion.