Voice over IP (VoIP) allows home telephone users to save on long distance and local telephone service. Users do not need computers in order to place phone calls over the Internet. Here are some of the ways which VoIP may be used.

Phone-to-Phone Calling
In VoIP phone-to-phone service, the home user uses their regular home phones no different than they currently do. (Just be sure that the 911 service is set-up correctly when a phone is ordered.). All that is required is for the user to install an ATA (analog phone adapters) that connects existing (analog) telephones to the modem.

These phones are the closest to land line telephone service, as it comes with a ten digit telephone number much like an existing telephone number, and users may use their current telephones.

Vonage is one of the VoIP service providers that offer phone-to-phone calling.

PC-to-Phone Calling
PC-to-Phone Calling is when a computer is used to call other telephone numbers. A software application, also referred to as soft phones, needs to be installed and configured with the computer’s sound card and microphone in order to begin usage. The interface on the computer resembles that of a regular telephone.

Most vendors charge a low monthly rates for the long distance service. Users of this service do not use this phone as their land line replacement, but as a means to save on long distance charges.

Skype is one of the providers that offer PC-to-phone calling.

PC-to-PC Calling
PC to PC Calling is the lowest costing means of IP Telephony, and most vendors are able to offer this service for free. This is because PC-to-PC calls never touch regular telephone networks, and purely travels through the Internet, much like the way Web pages are accessed freely. PC-to-PC calling interfaces are popular as part of Instant Messaging clients because both users are already online.

Live Messenger (formerly MSN Messenger) is an example of a PC-to-PC calling service.

Phone-to-PC Calling
Though technically feasible, phone to PC calling is unpopular as few users use their PCs as telephones and as a means of accepting incoming calls.