But the business case for Internet telephony is in flux.

Within this country, a potentially major force in Internet telephony could be the cable television industry.

For one, a company must make a considerable investment to switch to Internet telephony.

Despite its limitations, Internet telephony has caught the attention of large telecommunications companies.

Perhaps the biggest roadblock for Internet telephony is that different companies' systems almost never work with one another.

The technology's enthusiasts, who call it Internet telephony, are fighting back.

But much of the growing interest in so-called Internet telephony has to do with its relative simplicity.

His pet technology project, Internet telephony, is being introduced cautiously.

Many telecommunications companies are now using Internet telephony to route long-distance phone calls.

Even the proprietors of Internet telephony see their window closing.