In a nutshell, VoIP (Voice over Internet Protocol) is digital telephony that uses the Internet to transmit sound as data, as opposed to traditional analogue telephony that uses copper wires to transmit sound waves over an electrical current.
Developed back in the late 1970s, VoIP technology involves the conversion of speech or sound waves into digital data packets, just like emails or any other digital information, and the transmission of those digital packets across the Internet to their destination.
There they are reassembled in their correct sequence and converted back into sound waves in order to reconstruct the original speech. When this occurs simultaneously and practically instantaneously in both directions, a VoIP phone conversation can be said to be taking place.
VoIP can be accessed in several ways; via an ATA (Analogue Telephone Adaptor) which connects to your existing analogue handset, via a dedicated VoIP handset which plugs directly into your modem, or via a computer, using software and a headset with speakers and a microphone.
The quality of the Internet connection and the number of gateways that the data packages must travel through are what determine the quality of the VoIP calls that can be made.
If there are problems with the Internet connection then voice quality can suffer, producing symptoms such as jitter (jerky, jumbled playback of speech), packet loss (where data packets fail to arrive) and latency or lag (where the time it takes for the packets to arrive is delayed).
The advantages of VoIP technology over traditional analogue telephony may include;
The Internet is what made VoIP telephony possible and it is the development of faster and more consistent broadband connectivity, such as that offered by the NBN, that will make VoIP the preferred means of voice communication over distance well into the future.