BERKELEY -- 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.
