Most people today have an Internet connection, a cell phone, a landline (also called POTS, plain old telephone service) or two, and maybe even a pager or two-way radio. A trend toward converged communications is gaining momentum. The convergence, called IP (Internet Protocol) telephony, encompasses transmission of fax, data, video, and voice via the Internet. VOIP is pushing change -- in your telephone calls.

With VOIP, instead of taking place over a dedicated line, your conversations take place over the Internet. Even better, having a conversation over the Internet costs you considerably less than over a POTS line.

VOIP is a computer language used to send voice data over the Internet. During its early days in the mid-1990s. there was a push to use VOIP services that allowed users with specific software installed on their computers to call others with the same software installed. The calls had to be made using the computer and a microphone headset.
Those services were very rudimentary. The technology during that time was crude, and the result was poor quality phone calls that were unsynchronised and delayed. Those calls had the quality of conversations conducted using walkie-talkies. Only people using the same software could only receive those calls. Although the technology was infantile in nature, the speed of Internet connections also contributed to the lack of quality.

As with any other data, voice data can only travel as fast as the signal carrying it. When you're talking about dial-up service (the service typically used in the 90s), that's not very fast.
Today's VOIP is much more mature. It features dedicated hardware processing and more advanced communications protocols. The primary protocol used today is SIP (Sessions Initiation Protocol), which is designed to support voice transmissions.

H.323 used to be the primary protocol for delivering voice communications via the Internet; however, it was primarily designed for data transmission, making it inefficient for voice.
SIP is not the only protocol used today, however. Many vendors have proprietary protocols or, more commonly, use a combination of proprietary protocols and/or SIP and H.323. For you, this means increased call quality. These enhanced protocols, combined with broadband Internet access, translate into VOIP service that's as good as POTS in most cases.

A conversation using VOIP begins like any other phone conversation. In most cases, your telephone is connected to a box, which is connected to your Internet connection. That box, and analogue telephone adapter (also called a multimedia terminal adapter) converts your voice to packets of data. Those data packets are sent over the Internet to the switch that controls phone service at your call's destination, regardless of whether the person you're calling uses POTS or VOIP.
At that switch, the packets of data are decoded and reassembled so that the person receiving your call hears your voice, just as if you were speaking to them through a POTS line.

Today's VOIP makes it possible to have a telephone conversation, using the computer rather than the telephone. The main difference is in how the call data is carried from one end of the conversation to the other. Even the phone companies are using this method to transmit call data.

There's more than one way to use VOIP services. In fact, there are three. Although all three use the same core technology, the way that technology is accessed differs considerably.

• Internet Phone Service
• PC-to-PC Internet Phone
• Internal VOIP