- VoIP (Voice over Internet Protocol) is a system for transmitting voice calls over the internet.
- IP phones use an internet connection rather than phone lines for transmission, but otherwise work the same as traditional phones, including using area codes and phone numbers.
- VoIP can be substantially less expensive and more secure than traditional landline phones.
- Visit Insider’s Tech Reference library for more stories.
VoIP is shorthand for a telecommunication technology called Voice over Internet Protocol, and it’s a modern alternative to traditional phones. For a century or so, landline telephone systems have carried voice data over a network called the public switched telephone network (PTSN). VoIP, on the other hand, allows voice calls to be transmitted over the internet. Your VoIP phone is simply a node on the internet with an
, much like your
Although VoIP phones work over the internet, they behave almost exactly the same as traditional landline phones — they use area codes and phone numbers, not usernames or passcodes.
It’s also worth noting that even though your smartphone is an internet device and uses the cellular network to connect to the internet, phone calls you make with your voice plan are not VoIP — instead, cellular calls are transmitted using the voice cellular network. This is why most plans track voice and internet data usage separately.
How VoIP works
To use Voice over IP, you generally need a dedicated VoIP desktop phone (usually called an IP phone) which, instead of plugging into a phone jack, connects to the internet — usually by plugging into an internet router with an Ethernet cable or another form of high-speed internet connection.
To enable the phone, you need to subscribe to a service plan with a VoIP service provider. Generally, businesses have VoIP accounts which are substantially less expensive than traditional landline phone plans.
When you dial a phone number using a VoIP phone, the phone sends packets of data to the internet, which is transmitted much like any other kind of internet data. The VoIP service provider sends the data from your phone to the phone that was dialed, where the data arrived and is turned back into audio information.