Internet Phone

Internet Phone, like the the name says, refers to telephone calls over the Internet. Since the Internet can transport any media (text, pictures, sounds...) from one point to another, why not real-time voice. But here is the good news: it works almost as good as regular phone calls for a lot cheaper! Now I get your attention: a LOT cheaper!!

Internet Phone can be used in 3 different situations:

	PC-to-PC Internet Phone, where the call is between your computer and somebody else computer. This method requires both parties to be equipped with a computer, a sound card, a microphone, a connection to the Internet and a special communication software running on both computers. Click here to get started with PC-to-PC Internet Phone.
	PC-to-Phone Internet Phone, where the call is between your computer and a standard phone. This method requires only the caller to be equipped with a computer, a sound card, a microphone, a connection to the Internet, a special communication software and a subscription to a Telephony Internet Service Provider (TISP, which role is to forward the Internet phone call to the standard phone). Click here to get started with PC-to-Phone Internet Phone.
	Phone-to-Phone Internet Phone, where the call is between your good old phone to another good old phone This method requires the caller to subscribe to a Phone-to-Phone TISP such as AT&T, which will charge a per-minute rate, hopefully lower than regular phone companies. This method is not described in this page.

Getting started with PC-to-PC Internet Phone

PC-to-PC Internet Phone calls require both the caller and the callee to be equipped with the following:

	A computer, even the slowest Pentium will do just fine.
	A sound card, preferably full-duplex (to allow sending and receiving voice at the same time).
	A microphone and speakers/headphones, connected to the sound card.
	A subscription to an Internet Service Provider (ISP, whether it's AOL, CompuServe, or any global or local ISP) to connect to the Internet.
	A modem, ISDN, or cable modem... adapter to connect to the ISP. The connection speed should be at least 28.8K. Also, the quality will be much better with a digital line (ISDN, Cable modem...) than an analog one (modem).
	An Internet Phone software running on both parties computer to handle the communication. There many available, including Microsoft NetMeeting, IRIS IRISPhone, VocalTec Internet Phone, NetSpeak WebPhone, VDONet VDOPhone, VoxWare VoxPhone... Many of these software can do video phone as well, but that requires a much faster connection to the Internet to work well (even 128k ISDN is far from enough). for in-depth review of these products, click here. I chose Internet Phone from VocalTec because it has the best phone quality, the software is very nice and can be used for both PC-to-PC and PC-to-Phone Internet Phone calls.

A PC-to-PC Internet Phone call starts by having both parties (the caller A and the callee B) install and run the same Internet Phone software (it must be the same software) on their respective PCs and connect, using that software to the server of the company providing the software (Internet Phone providers are called Telephony Internet Service Providers, or TISP). Once connected to the TISP server, A calls B using the Call function of the software (you can search for the person to call by the e-mail address). Once the TISP server has established a connection between A and B, A's voice goes from A's microphone to A's sound card, where it is digitized, then to A's modem and over to A's ISP, where it is split into small Internet packets of data and sent over to the TISP server. The TISP server then receives all these packets, and forward them to B's ISP where they are reassembled, and sent to B's modem, then B's sound card, then B's headphones.

PC-to-PC Internet phone calls are free, in a sense that you don't have to subscribe (registration is free) to any particular service to operate calls (note their software may not be free). The only costs for such calls are your usual ISP monthly fee (charged by the ISP) + the local phone call to the ISP (charged by the local phone company).

Getting started with PC-to-Phone Internet Phone

PC-to-Phone Internet Phone calls require the caller (only the caller) to be equipped with everything described in the PC-to-PC Internet Phone section, plus a subscription to a Telephony Internet Service Provider (TISP) which provides a PC-to-Phone services. Not all companies mentionned in the previous section can handle PC-to-Phone Internet Phone. The two most famous ones are VocalTec (which uses DeltaThree servers) and Net2Phone.

PC-to-Phone Internet Phone calls start by the caller registering himself on a TISP server, using the software provided by the TISP. The registration process includes passing the callee's phone number (the real phone number). Once registered, the caller calls the callee using the Call function of that software. Once the TISP server has established a connection between the caller and the callee, the voice goes from the microphone to the sound card, where it is digitized, then to the modem and over to the ISP, where it is split into small Internet packets of data and sent over to the TISP server. The TISP server then receives all these packets, and forward them to another server of the same TISP, but physically close to the callee. That second TISP server then receives all these packets, reassembles them, analogized the signal, and puts it on the regular phone line, in connection with the callee.

PC-to-Phone Internet phone calls are NOT free. On top of the caller's charges for connecting to the Internet are added a per-minute rate charged by the PC-to-Phone TISP (which is hopefully a lot less than regular phone companies).

This page was last updated by JP on 12/03/98.