April 13, 1998
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
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
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
"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
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 (http://www.lbl.gov)
is a U.S. Department of Energy national laboratory located in Berkeley,
Calif. It conducts unclassified research and is managed by the University