A Voice over Internet Protocol (VoIP) phone uses Internet Protocol (IP) technology to transmit calls with the aid of either specialised digital hardware or a program that runs on a computer or mobile device. A VoIP telephone converts sound into packets of data and sends it through the Internet to a network. On the receiving end, the phone decompresses the data and plays it back for the recipient to hear.
VoIP vs traditional phone systems
A traditional business phone system is connected by wire to an on-premise private branch exchange (PBX). A PBX manages all routing and ensures all calls reach their destination through the public switched telephone network (PSTN) or plain old telephone service (POTS), a colloquial term for PSTN.
What is a VoIP phone and how does it work?
Voice over IP technology comprises several protocols working together to replicate telephony functions. Each protocol has a different function, but all are working simultaneously in real-time. Here is a brief description of the protocol:
- Session Initiation Protocol (SIP)
SIP protocol is the signalling component of the technology and sets up real-time multimedia sessions between two or more participants over the Internet.
- Real-time Transport Protocol or RTP
RTP is the technology that carries the digital voice audio data packet back and forth during VoIP phone calls.