Voice over Internet Protocol, also called VoIP, IP Telephony, Internet telephony, Broadband telephony, Broadband Phone and Voice over Broadband is the routing of voice conversations over the Internet or through any other IP-based network.

In simpler terms VoIP (Voice over Internet Protocol) is Internet phone service that bypasses your normal local telephone company. Internet VoIP service rings and has a dial tone just like any other telephone, but calls are routed over your Internet connection. VoIP's growing popularity is lowering the cost of phone communication for many homes, and for some, it’s eliminating plain old telephone service (POTS) entirely. Unlike traditional analog telephone signals, which travel through a PSTN (public switched telephone network), VoIP digitizes the speaker's voice and sends it through either cable or DSL broadband Internet connections. An adapter connects your regular telephone to your Internet connection.

Many companies, including Vonage, 8x8 and AT&T (CallVantage), typically offer calling within the country for a fixed fee and a low per-minute charge for international. Broadband Internet access (cable or DSL) is required, and regular house phones plug into an analog telephone adapter (ATA) provided by the company or purchased from a third party.

Telephone Adapter Based
VoIP services that use regular telephones can generally make calls to any regular phone and receive calls from any phone.

Softphone Based
Software-based phones require using the computer to make and receive calls. Usually a no-cost option if both sides are on the same service, softphones also mean you can call any phone in the world no matter where you are in the world from your laptop (with an Internet connection). Per-minute charges apply for calling regular phone numbers, but you may not be able to receive a call from a regular phone. In 1995, VocalTec Communications introduced the first VoIP service in the U.S., which was softphone based (see Internet Phone).

VoIP Features
Voice mail, caller ID, call forwarding and a softphone option are typically part of a VoIP package. You may also be able to choose phone numbers with home area codes outside your geographic location (see virtual phone number). See IP telephony for more details and history of the technology.

VoIP Providers

Companies providing VoIP service are commonly referred to as providers, and protocols which are used to carry voice signals over the IP network are commonly referred to as Voice over IP or VoIP protocols. They may be viewed as commercial realizations of the experimental Network Voice Protocol (1973) invented for the ARPANET providers. Some cost savings are due to utilizing a single network - see attached image - to carry voice and data, especially where users have existing underutilized network capacity that can carry VoIP at no additional cost. VoIP to VoIP phone calls are sometimes free, while VoIP to public switched telephone networks, PSTN, may have a cost that's borne by the VoIP user.

Prices for Internet calling vary, but virtually every provider offers an unlimited domestic dialing plan that serves as a nice point of comparison. Here's a look at some of the best-known VoIP services.

AT&T CallVantage
Plan: Unlimited
$30 activation fee, plus $10 shipping charge for adapter
A safe VoIP choice, AT&T gave Internet phone services instant credibility when it jumped onto the scene. Prices are a bit high, but users rave about the quality of service. AT&T no longer markets traditional consumer phone services, so its commitment to VoIP seems real.

Vonage Digital Voice
Plan: Unlimited.
$30 activation fee. No contract. $40 termination fee after one year.
This is the company that pushed VoIP over the top. Vonage offers a compelling blend of low cost, reasonable features, and excellent nationwide coverage. This fast-growing service has suffered glitches in the past, which should give risk-adverse adopters cause to think.

Cox Digital Telephone
$20 line activation fee. Modem has battery-powered back-up capabilities, in case the electricity fails. Unlimited calling in U.S.

Skype
Free calls to anyone with installed Skype software. Calls from your computer to regular phones cost about 2¢ s per minute to the U.S. and Canada, plus most of Europe and Australia.

Cordless Skype Phone

• No PC Required

• Make Skype calls without a computer

New VoIP solutions: A stand alone Skype device that does not require a PC.

Dualphone 3088

Finally a cordless Skype phone that does not require a PC. Just connect the DUALphone base station to your broadband connection, and then you can talk free of charge with your Skype friends or call other landline numbers worldwide – either using the extremely low SkypeOut rates or as usual via your regular landline operator. The popular Skype user interface and the attractive colour display gives you tomorrow's telephone today and for the future, because it is easy and simple to download new software directly from the phone.The phone has superior sound quality, is naturally cordless and has a range of up to 300 metres. It is easy to install, easy to use and a natural choice as your conference phone.

Main features

• Stand-alone Cordless Phone for Skype and ordinary phone in one
• No need for a PC – just connect the DUALphone base station directly to your broadband router or modem
• Intuitive Skype graphical user interface
• Cordless phone using DECT – Digital Enhanced Cordless Telecommunications
• Free Internet telephony via Skype to other Skype users
• SkypeOutTM to or SkypeInTM from any phone number
• Ordinary telephony via your landline operator – Public Switched Telephone Network (PSTN)