Its service is simple. Vonage sends customers an Internet phone box, which looks like a small cable TV box. The box plugs into most high-speed Internet connections. Almost any telephone plugs into the box.
The phone works like any other phone, but Vonage is routing the calls over the Web. (If the person on the other end of the line is not a Vonage user, the call will hop onto a regular phone line for the very last leg of its journey.)
This is the future.