Infographic: How Does VoIP Work?


Wondering about the simple working principles behind VoIP technology? VoIP technology runs on some very simple principles. Basically, VoIP works by connecting telephones and computers through their IP addresses. Every private network that is connected to the Internet has an IP address. An IP address is just like a street address. If you were a packet of data trying to find your way through the Internet, you could find your destination on the map with an IP address.

So, when you get a phone service in your home or business, your telephone service provider is basically using your home or office IP address (if you already have Internet, you already have an IP address) as the location of your phone number. 

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How Does VoIP Work?

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Once you have purchased your VoIP service, you can make free VoIP calls through your personal computers, your IP phones, your analog phones with adapters, and even your smartphones and tablets. Your VoIP service provider routes your call through the Internet based on IP addresses, rather than through copper telephone lines. All you need is a complete Internet setup, which will require a modem (and maybe a router) in your home or office so you can access the Internet, and you will be VoIP-ready!

Now, if all calls were based on IP phone technology, a packet of voice data would never have to leave the Internet, and could be routed entirely by IP address. However, many people still use cellular service and analog telephone service. So how do you make a VoIP call to someone who doesn’t use VoIP?

Basically, if you need to dial a phone number that is not hosted by a VoIP provider, your Internet telephony service provider will recognize that the destination number is not hosted by a VoIP company, and will transfer the packet of voice data over to the correct analog or cellular carrier. So, if you have a VoIP service with ITP in your home, but your grandmother still has an analog service with Verizon, you can dial your grandmother’s number, your call will travel through the Internet to ITP, ITP will recognize that your grandmother’s number is not hosted by ITP, and will connect the call to Verizon, which will then connect the call to your grandmother.

This means there is no difference in user-feel between VoIP and traditional phone services. You can still call everyone you want to call. In fact, you will only stand to gain, and you won’t lose anything. Most VoIP providers offer number porting so you can keep your current number, and many offer lots of free features so you can actually improve your experience with your phone service while actually saving money!


Jackson Weber's picture
Jackson Weber, editor of is a graduate from the University of Michigan, with a special focus in rhetoric and technical writing. Using these skill sets in conjunction with heavy research, Jackson stays ahead of the latest VoIP technology. He always finds the latest information on everything from SIP trunks to cloud-based PBX services, and breaks it down in plain English that almost anyone can understand.