MIT researchers calculate river networks’ movement across a landscape.
Each day, thousands of Internet users are discovering something that sounds too good to be true: they can use their computers to make free telephone calls anywhere in the world. Dr. Lee McKnight of MIT has organized a consortium that is studying the broad implications of this new ability for traditional telephony, telephone companies and the Internet itself.
The growing list of consortium members includes Southwestern Bell, Sprint, Nokia, US Robotics, Lucent Technologies, Mediatrix, VocalTec, Netspeak and Netphone, as well as other European telecommunications companies.
Dr. McKnight, associate director for research and management at the Research Program on Communications Policy (RPCP) in the Center for Technology, Policy and Industrial Development, has brought together the group to examine the growing use of the Internet for real-time fax, voice and video transmissions. The MIT-based think tank is called the Internet Telephony Interoperability Consortium, or ITI.
Over the past year or so, new users of new software and services on the World Wide Web can speak through their computers to other computers or even to a telephone. The cost for the call, depending on the service they choose, may be included in the monthly Internet fee. Thus, someone with unlimited access to the Internet in the United States can talk to someone halfway around the world all day long for no extra cost. And if they both have the proper video connection, a feature common on some Macintosh computers, they could even see each other.
Phone quality on the Internet depends on three things: the software, the computer and the connection. The ordinary telephone is still easier to use and usually offers better quality. The attraction of the Internet phone for now is that the calls cost no more than one's monthly Web-surfing fee.
Dr. McKnight sees the Internet moving away from this "free ride" concept, however. The Internet won't replace the telephone this decade, he said, "but soon there could be a whole range of Internet/telephony services, with new applications that we can't dream of today." In fact, standardized services for telephone, Internet and television could theoretically be combined.
"No one is really sure right now how this technology will be regulated or what financial model will be used," said Dr. McKnight, the consortium's principal investigator. "So the idea behind ITI is to bring people from different industries and backgrounds together to remove the barriers to growth of Internet telephony and multimedia businesses by developing unbiased and supportable information and technology." A core concept of the consortium is interoperability-the ability for applications and services to work between systems.
The ITI will examine pricing of reliable services, regulatory issues and business effects, as well as technical, political and economic factors affecting infrastructure investment related to voice services over the Internet, innovation strategies and load management
MIT advisors to the project include David Clark, chair of the Consortium's advisory committee and senior research scientist at the Laboratory for Computer Science; John Wroclawski, also of LCS; and other researchers and faculty from electrical engineering and computer science, economics and the Sloan School of Management. Former visiting scholar Dr. Petros Kavassalis and graduate students Joseph Bailey (EECS) and Andrew Sears (EECS and the Technology and Policy Program) were key contributors to the preliminary research effort and are still active within the consortium.
At the beginning of this year, phone companies thought that Internet telephony would pose little threat to their business because the software lacked sophistication and reliability. But since then, quality has improved, the estimated 2 million users has doubled, and the America's Carriers Telecommunications Association-a trade group of long-distance carriers-has petitioned the FCC to prohibit the marketing of Internet telephone software.
Like audio conferencing programs, Internet telephones work by digitizing speech and transmitting the data. But there are a few problems. A typical Internet connection with a 14.4-Kbps modem can send and receive a maximum of 1,800 bytes of non-compressible data each second. Telephone-quality speech typically needs 8,000 bytes per second (or 64 Kbps) of bandwidth.
Two possible solutions are obtaining more bandwidth or compressing the information before transmitting it. Although both solutions are used, most Internet telephone applications compress the audio. And this leads to a second problem: compatibility. Until existing standards are firmly established, Windows users might not be able to talk to Mac or Unix users and vice versa. Even users on the same computer platform might not be able to communicate without the same software. Furthermore, the quality could be fine one day but slow or distorted the next.
A third potentially problematic issue is the requirement for a computer faster than 33 MHz with sound capability and a microphone. Most new Mac and Unix machines come with duplex sound which allows simultaneous two-way conversation, as opposed to the "walkie-talkie" half-duplex sound. Most PC-DOS machines have only half-duplex.
The ITI has a Web site at
RPCP has its foundation in communications policy, from its work with high-definition television to research on Internet economics. For more information about the consortium, contact RPCP at
(This article was originally written for the fall issue of Technology and Policy, CTPID's newsletter, scheduled to appear this week).
A version of this article appeared in MIT Tech Talk on November 6, 1996.