If phoning anywhere in the world for the price of a local call sounds far-fetched, think again. Email and the Web might have driven the Internet's success so far, but Internet telephony could be the application that gets everyone connected.
Put simply, Internet telephony involves using the Net rather than telephone trunks to carry voice calls. More than 60 companies are already offering IP telephone products, and although the connection quality has traditionally been poor, the latest Internet phone software can provide quality of service close to that of ordinary phone calls, provided you have a reasonably fast machine (e.g. Pentium 60Mhz or better) with speakers or headphones, a microphone, a sound card (preferable full-duplex), and a fast Internet connection (at least a 28.8 kbps modem).
The first wave of Internet phones only allowed calls from computer to computer. Newer services allow calls to ordinary telephones too. One of the most popular of the first type is Webphone, developed by Netspeak (www.netspeak.com). Its latest version provides a virtual telephone on your screen, allowing you to connect to other Webphone users with voice, video and text communications, and includes a bunch of standard telephony features such as multiple lines, conference calls, voice mail and call holding. The full costs around $50, but a free, scaled-down version allows you make three-minute calls to test it out.
With Webphone and similar products, calls cost no more than the cost of connecting to the Net - usually a local call to your ISP. The drawback is that you can only call someone who has identical software and who is also currently connected to the Net. This may be useful for business users whose computers are continually online, but it is not so suitable for personal users: unless you arrange the time of the call in advance it is unlikely the person you're calling will be online.
This is where the second type of Internet telephony is useful. A new breed of ITSPs (Internet Telephony Service Providers) is springing up, allowing users to make calls from computers to ordinary phones.
A leading supplier of this type of Internet telephone is Israeli company VocalTel (www.vocaltel.com). Like WebPhone, its on-screen telephone called Internet Phone can be downloaded from the Web (and also costs about $50). Since last August VocalTel users can get an account with an ITSP of their choice, which usually means supplying credit card details and paying for calls in advance. They can then use Internet Phone to call any number in the world. Calls are routed over the Net to a telephony gateway - a device connecting the Internet to an ordinary telephone network. The nearer a gateway is to the destination number, the cheaper the call. Hence the cost per call depends solely on the destination, regardless of origin.
ITSP call charges, over and above the cost of connecting to the Net, are often much cheaper than regular long-distance phone calls. For example, the Florida-based ITSP WIN (www.wininc.com) charges calls to the US at $0.12 (8p) per minute from anywhere on the Internet, calls to Ireland at $0.54 (36p) per minute, and calls to the UK at $0.29 (19p) per minute. Even allowing for a peak rate local call to an ISP, this means a three-minute call to from Ireland to the US would cost 36p.
The savings are possible because the Internet is used to carry the voice data most of the way, though this does cause a reduction in quality. The nature of data delivery on the Net means packets of data may arrive in a different order to which they were sent, leading to gaps and pauses in conversation when links are busy. Companies already using Internet telephony for cheaper customer services - they no longer need costly 1800 numbers - are training their employees to speak in short phrases, with longer pauses, to allow for these delay times.
According to Internet telephony consultants Virtual Voice (www.virtual-voice.com), the biggest drawbacks are "the speed of your Internet connection, traffic conditions on the Internet, and the speed of your computer". This is likely to become a greater problem as the Internet gets busier. Although new versions of Internet telephony software are more efficient (less bits are used to represent the voice and video signals), more and more people are likely to use the Internet to make their long-distance calls, especially as ITSPs offer telephone-to-telephone connections, bringing Internet telephony to people without computers. One such project, called Free World Dialup (www.pulver.com/fwd) aims to offer free calls for personal, non-commercial use.
There's a catch. The lure of cheap international calls is likely to cause a huge increase in the amount of traffic on Internet backbones, reducing the quality of Internet telephony unless there is a corresponding increase in bandwidth. Internet telephony will either become a victim of its own success, or it will be the catalyst for even faster Internet growth.
Eoin Licken is at eoinl@iol.ie