Networking: The Next Generation
By Kate Metropolis
Rapid, reliable data transport is essential for global scientific
collaborations to gain new knowledge. SLAC was recently honored for its
contributions to highspeed networked computing.
Congratulations from U.S.
Congresswoman Anna Eshoo. (Image Courtesy
of Les Cottrell)
Data are nature’s gift to scientists, but
the gift can at times feel like a curse. To address some key questions
in their fields, researchers at the frontiers of particle physics,
astronomy, bioinformatics, global climate modeling and seismology need
to harvest, store, share and analyze staggering quantities of
collaboration ships about a terabyte of data every
24 hours between SLAC and computing centers in France, Italy, and
England—the equivalent of a thousand copies of the Encyclopedia
Britannica a day. To continue to make scientific breakthroughs, their
dataset needs to roughly double every year.
By the year 2010, when a new generation
of experiments will be underway, the high energy physics community
anticipates that datasets will reach 100 petabytes, the digital
equivalent of 20,000 times all the text in the Library of Congress.
Thousands of physicists and students at institutions around the world
will want to access and process them using petaflops of distributed
computing. (A petabyte is 1 billion megabytes; a petaflop is 1 million
billion computations per second.)
The computing tools to provide these capabilities are being developed by
the leaders in high-performance computing at SLAC and their colleagues
around the world.
Teams of physicists from Caltech, SLAC, LANL, CERN, Fermilab, Florida
International University, University of Florida, University of Michigan,
BNL, and the MIT Haystack Observatory are focused on optimizing the use
of the Grid for data-intensive science. The Information Grid is
analogous to the electric power grid. Just as you toast your bagel in
blissful ignorance of which power generators your toaster is drawing
electricity from, you’ll analyze data using a geographically distributed
network of computational resources, without ever knowing where they are.
The collaboration, which also includes experts from U.S. industry, is
building a permanent facility for testing, tuning and using applications
from physics and astronomy that require reliable data transfers at rates
of up to 10 gigabits per second.
The partnership is named UltraLight because data are transmitted as
pulses of light. A single optical fiber can transmit information at 10
gigabits per second using one frequency. By using different wavelengths,
that same fiber can carry more than 100 different signals
Networking knowledge, experience and innovations from the UltraLight
partnership will also be invaluable for developing the gigabit
state-wide network being built to serve millions of Californians. These
contributions were recognized last month by CENIC, a not-for-profit
corporation dedicated to facilitating advanced network services for
research and education in California. Ultralight won CENIC’s second
annual ‘On the Road to a Gigabit’ Award, announced in March, for “the
best use of highperformance networking developed by a private/public
UltraLight is building on an earlier triumph. At the Supercomputing 2003
conference: a team from SLAC, Caltech, LANL, CERN, Manchester and
Amsterdam, with assistance from private industry, set a world record for
fastest data transmission last November: 6.6 terabytes in 48 minutes, a
rate of 23.2 gigabits per second (see TIP, Dec. 12, 2003). This is the
equivalent of about 2,000 featurelength DVD-quality movies. The goal was
to demonstrate what can be achieved with technologies that are readily
“We wanted to open people’s eyes,” said SCS Assistant Director Les
Cottrell, “and get them thinking, ‘What would I do if I had this
“The way you move data shapes the design of experiments,” says Cottrell.
“Until the late 1990’s, most high energy physics data were transferred
on tapes. At SLAC alone, producing, packaging and shipping the tapes
took the full-time effort of two people.” How long did it take for data
from SLAC to reach a researcher at CERN? Two weeks.
In a broader context, Cottrell believes the team’s results will
stimulate scientists and engineers in other areas to invent new models
for collaboration in research and business. People around the world will
be able to share their computing resources and information with
unprecedented ease and efficiency.