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Priority Service For Internet Traffic Demonstrated

April 15, 1998
Lawrence Berkeley National Laboratory
Scientists at two Department of Energy national laboratories have successfully marked selected Internet traffic for priority service over unmarked, lower-priority traffic in a cross-country demonstration.

BERKELEY, CA. - Scientists at two Department of Energy national laboratories have successfully marked selected Internet traffic for priority service over unmarked, lower-priority traffic in a cross-country demonstration.

This demonstration is a key milestone in the development of a broad set of capabilities called "Differentiated Services" which are required for the Internet to be able to give different levels of service on demand to network customers. The demonstration of such capabilities for production-mode scientific research between Lawrence Berkeley and Argonne national laboratories will pave the way for more reliable and constant connectivity via priority bandwidth on the Internet.

The demonstration involved sending two video streams over the Internet from Berkeley to Argonne in Illinois. In a test sharing an intentionally congested path, the priority-marked stream moved at eight frames per second, while the standard version transmitted just one frame per second.

Typically, Internet users encounter a wide variety of cybertraffic conditions, ranging from free-flowing traffic to peak-hour jams to complete stalls. With Internet traffic growing by 400 percent annually, such congestion will continue to be a problem. This situation has left many users wishing for a more reliable level of Internet service. The current quality of service, called "best effort," often leaves room for improvement.

Differentiated services will replace "best effort" by providing specialized services for Internet users who need it and are willing to pay for it. The idea behind differentiated services is similar to reserving a first-class, business class or coach seat on a commercial airline. One means of providing differentiated services is through a technology called "class-based queuing" developed at Berkeley Lab.

The new differentiated services technology is expected to demonstrate to industry how different levels of quality of service can be implemented and deployed on a practical basis. The technology is also expected to make it significantly easier to send audio and video signals across the Internet.

Achieving this improved level of service is essential to the work of the Department of Energy, which is pioneering the use of various technologies to allow scientists at more than 30 DOE national labs to share access to some of the nation's most advanced research facilities. Having connections that can disrupt real-time research collaborations in such fields as biomedical research or environmental restoration can result in both human and financial costs. Reliable connections allow researchers around the nation to make effective use of the some of the world's top scientific facilities.

The DOE already has one of the fastest and most reliable "backbone" networks of the Internet - the Energy Sciences Network, or ESnet. Scientists at Berkeley and Argonne regularly rely on ESnet to conduct collaborative research in structural biology, materials science and physics.

"For more than a decade, DOE computer scientists have helped develop technologies that have brought the Internet to the level it is today, and differentiated services is another key step toward tomorrow's network capabilities," said C. William McCurdy, head of the Computing Sciences organization at Berkeley Lab. "The fact that Berkeley Lab operates DOE's primary network and has a world-class network research group gives us the chance both to make developments like this one and then to test them in a real network."

Although the idea of differentiated services is simple, coming up with the enabling technology was more difficult. Because the Internet is actually made up of millions of interconnected networks, the technology had to be able to scale up to work across the entire system. Hardware also had to be developed to differentiate between different levels of priority for Internet traffic.

The link between Berkeley and Argonne uses new software to recognize specially marked data packets so that the various networks and Internet routers will give them priority over packets which are not similarly labeled. In limited tests last November, Berkeley Lab computer scientists successfully proved that the priority-marked packets were routed through points of congestion, while similar data in unmarked packets were lost.

The software for marking the priority packets was developed at Berkeley Lab. Using this software, a policy decision of whom to give priority to is translated into special router commands to mark the appropriate packets for priority delivery. This work, as well as class-based queuing and many of the original key ideas for differentiated service, stems from research done by Van Jacobson and his Network Research Group at Berkeley Lab.

Today's demonstration fits together various technologies at Berkeley and Argonne labs, Cisco Systems and Sprint Telecommunications. It is a result of a decade of research into Internet quality of service. Two years ago, the Internet community began to pursue differentiated services, which resulted in the approach taken in the labs' demonstration.

The successful demonstration also signifies a new level of coordination of computer networking research and network operations at Lawrence Berkeley National Laboratory. Two years ago, DOE moved ESnet operations and administration and the National Energy Research Scientific Computing Center to Berkeley Lab to foster greater collaboration between the research and production organizations.

"By giving scientists capabilities that are not yet available on commercial networks, ESnet is both creating new opportunities for scientific research and also contributing to the evolution of the Internet," said Jim Leighton, head of ESnet and the Networking and Telecommunications Department at Berkeley Lab. "This demonstration is the precursor to better service for nearly anyone who relies on the Internet."

Berkeley Lab ( is a U.S. Department of Energy national laboratory located in Berkeley, Calif. It conducts unclassified research and is managed by the University of California.

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Materials provided by Lawrence Berkeley National Laboratory. Note: Content may be edited for style and length.

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Lawrence Berkeley National Laboratory. "Priority Service For Internet Traffic Demonstrated." ScienceDaily. ScienceDaily, 15 April 1998. <>.
Lawrence Berkeley National Laboratory. (1998, April 15). Priority Service For Internet Traffic Demonstrated. ScienceDaily. Retrieved May 24, 2024 from
Lawrence Berkeley National Laboratory. "Priority Service For Internet Traffic Demonstrated." ScienceDaily. (accessed May 24, 2024).

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