VoIP CONNECTIONS VIA THE PHONE NETWORK

There are several companies that provide VoIP services which allow you to connect to the existing phone network. This means that even though you are using VoIP technology, you can dial "regular" phone numbers and receive calls at a certain number.

Some of these companies target large corporate customers and provide "full-service" solutions, integrating company directory, fax, email services, etc. We won't consider these services as they are usuall come with a completely different set of requirements than those of consumers, freelancers and small businesses. For these categories of users, the spectrum of choices includes:

TWO TYPES OF "PHONE-NETWORK-INTEGRATED" VoIP SERVICES

A convenient way to group these services is by their hardware requirements, that is to say, by whether they require a computer to place and receive calls:

NO COMPUTER REQUIRED Companies that offer fully integrated solutions not requiring computer (Vonage, Packet8). With these services, you can use regular telephones. How does it work? When you sign up for the service, the VoIP company sends you what's called a "terminal adapter" (DTA) that plugs into the Internet (usually through a router, which you may or may not already have) in your home or office. Then you plug your regular phone into the adapter and get the dialtone.

Although the underlying technology is VoIP and you do need a broadband Internet connection (and possibly a router), no computer is necessary.
COMPUTER/SOFTWARE REQUIRED Companies offering computer-based services that are partially integrated into the telephone network. There are companies such as Net2Phone and WebPhone which allow you to dial regular phone numbers using software running on your computer as the main interface to the VoIP service.

ISSUES AFFECTING PHONE NETWORK SERVICES

The biggest questions are:

911 (in the US) or other emergency services
Keeping / transferring previous phone number