One of the main advantages of VoIP is the low cost. If you have a fast Internet connection (DSL or cable) you can make PC-to-PC phone calls anywhere in the world for free. If you wish to make a PC-to-phone connection, however, there's usually a charge for this but probably much cheaper than your regular phone service.

You can also sign up with a VoIP service provider which charges a monthly fee in return for unlimited calls within a certain geographic area. For example, some VoIP services in the United States allow you to call anywhere in North America at no extra charge. Overseas calls are charged at a relatively small rate.

Another advantage of VoIP is portability. You can make and receive phone calls wherever there is a broadband connection simply by signing in to your VoIP account. This makes VoIP as convenient as e-mail – if you are travelling, simply pack a headset or Internet phone and you can talk to your family or business associates for almost nothing.

Phone-to-phone VoIP is also portable. When you sign up with a VoIP service provider the Internet phone or adaptor that is used with that service is assigned a unique number. This 'phone number' remains valid even if your VoIP service is in Cleveland and you are connected to the Internet in Bangkok. An Internet phone is small and light enough to take with you anywhere. Simply plug it into a broadband connection anywhere in the world and you can make and receive calls just as though you were in your own home or office.

There are many other features that make VoIP attractive. Call forwarding, call waiting, voicemail, caller ID and three-way calling are some of the many services included with Internet telephone at no extra charge. You can also send data such as pictures and documents at the same time you are talking on the phone.