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As you read this sentence, multiple streams of data -- totaling billions of bits per second -- are being transmitted over strands of optical fiber, which is hair-thin plastic or glass wire used to shunt information using infrared or visible light. While this kind of high-speed networking in the aggregate is achievable today -- that is, the ability to transfer, at once, billions of bits of information through a single fiber-optic line across multiple data streams -- the real technical challenge remains in delivering a single, high-speed data stream, from end-to-end, directly to the user's desktop.
The NASA Research and Education Network (NREN) Project is administered by the agency's High Performance Computing and Communications Program. Along with partners from other federal agencies, industry and academia, a dedicated NREN team is already demonstrating the future when ultra-fast, data-intensive, computer networking will be commonplace. An emerging technology of interest to NASA -- known as gigabit networking -- promises to deliver the high-speed goods on a number of fronts. A gigabit is one billion bits of information, and a gigabit network is the way to transmit enormous amounts of information. While maturation of this technology lagged for years, due primarily to computer network bandwidth limitations, it now has the proverbial green light to come of age. Through the NREN Project, whose goal is to infuse emerging networking technologies such as gigabit networking into NASA applications, gigabit networking is fast becoming a vital part of the Next Generation Internet (NGI) initiative. NGI is a national effort among government, academia and the private sector to create the Internet of the future. As part of the initiative, the NREN Project seeks to infuse gigabit networking technologies throughout the agency. Eventually, as the technology becomes essential to NASA's operational networks and applications, it will provide NASA computer users the remarkable ability to work with each other at remote locations as if they were next door.
Gigabit networking applications within NASA will include rapid data transfer in everything from research and development and space missions to public outreach and educational activities, according to Marjory Johnson, NREN associate project manager. "With our gigabit networking applications, NREN hopes to set the pace for future commercial use of the technology," Johnson says. As a multitude of uses for gigabit networking are being identified, the NREN team -- as with other groups -- is working to fine-tune the technology, as well as to demonstrate its capabilities, according to Johnson. Moving billions of bits What is gigabit networking? Simply put, a gigabit-per-second network speed is one billion bits of electronic information transmitted per second. Gigabit networking, then, offers the capability of moving a billion bits of data per second -- many times faster than the computer networks that most people are currently familiar with. This technology opens up possibilities for exciting new applications. Distributed multimedia conferencing for graphics, voice, video, high-definition TV and virtual reality will rely on gigabit networking. More importantly, demanding NASA science and engineering applications can be deployed that use visualization, computation and storage resources at multiple network locations, achieving an unprecedented ability for researchers distributed throughout NASA to work collaboratively.
What kind of gigabit networks are deployed? One type is a local area network (LAN). The most familiar type of LAN is Ethernet. A megabit is one million bits. Ten-megabits-per-second Ethernet is widely deployed in offices, computer rooms and even some homes. It has been the most common method to connect PCs, printers and network servers during the past two decades. Today, gigabit networking such as Gigabit Ethernet can run one hundred times faster than the original Ethernet. Ten-Gigabit Ethernet is currently being standardized and will be 1,000 times faster than the original Ethernet. Another type of network in which gigabit networking is being deployed is the wide area network (WAN). A WAN is a geographically dispersed telecommunications network. Today, the highest-speed WANs run at 2.5 gigabits per second. Even-faster links are being tested. These fiber-optic links run at aggregates of ten-gigabits-per-second speeds, the same as the ten-gigabit Ethernet and 1,000 times the speed of the common ten-megabits-per-second Ethernet speed. Advances in optical fiber, lasers and semiconductors have enabled high-bandwidth, long-distance optical technology connection speeds to exceed that of early WAN links by a factor of a million. At the same time, between 16 and 100 separate wavelengths of light traveling over a single optical fiber permits many connections to travel over the WAN link simultaneously. This amazing capability -- going from one wavelength to 100 -- allows hundreds of gigabits per second, perhaps even one terabit (a trillion bits per second) of total traffic to travel over a single optical communications line. Beyond exploring the best options for deploying gigabit networking, the NREN team is demonstrating that many factors besides raw network bandwidth must be examined, especially when rapidly accessing and manipulating enormous amounts of data over networks is required. For example, one area NREN explores concerns packets. A packet is the basic unit of network data. Messages are assembled in packets and marked with an address and other information for routing purposes. The size of packets, the time it takes packets to travel over a WAN, the likelihood of a packet being dropped along the way, and the total amount of data sent but not acknowledged are all factors that must be managed consistently in order for the user's application to achieve the promised speed.
Gigabit networking applications From the study of ultra-small, sub-atomic particles to immense galactic structures, gigabit networking technology will help NASA researchers, who rely on high-performance computing and communications technology, to probe the mysteries of the universe. Working closely with both NASA's Numerical Aerospace Simulation (NAS) Systems Division and the Astrobiology Institute at Ames Research Center in California, the NREN Project is providing gigabit networking technology to demonstrate Virtual MechanoSynthesis (VMS), a 3-D simulator that allows users to see, move and even feel simulated molecular structures. VMS is an important tool to help scientists better understand how to design nano-electronic components, chemical- and bio-sensors, and nanotubes. Gigabit networking handles the data-intensive VMS communications at high speed and enables a VMS simulation environment to run simultaneously in multiple locations so groups of scientists can work collaboratively in real time. "With VMS a user can grab an individual atom with a wand, move it about, and build complex structures," says Jon Guice, an information technology researcher at NASA's Astrobiology Institute. "VMS uses computational steering -- the ability to design and modify simulations interactively."
Guice says gigabit networking is important to VMS's viability because it is the best way to deliver the enormous data required by multiple, distant users. VMS, he notes, has many potential applications in biology and medicine, and NREN's involvement in testing VMS on a high-speed network is a critical step on the road toward demonstrating its value as a research tool. In another example of demonstrating the value of gigabit technology for NASA operations, NREN engineers are working with scientists at the Jet Propulsion Laboratory (JPL) to deliver data and link users of the Digital Sky Virtual Observatory. Digital Sky is an astronomical data treasure trove that will enable viewing of tens of terabytes of archived space image and related information. David Curkendall, manager of JPL's High Performance Information Technology Office, says, "Digital Sky and the future National Virtual Observatory are exciting new NASA/National Science Foundation programs knitting together geographically distributed collections of data of the entire sky at various wavelengths of the electromagnetic spectrum. If the goals of these programs are to be met, it must be possible to routinely transmit terabytes of data from the distributed archives to the points of virtual observation and analysis." That fact alone, Curkendall stresses, is what makes NREN's gigabit networking knowledge crucial to the success of Digital Sky.
Some day, astronomers combing through Digital Sky's vast holdings may discover new galaxies, stars and planets, showing that by linking basic research with the power of high-speed communication, the sky literally is the limit. "Demonstrations such as Virtual MechanoSynthesis and Digital Sky are proof that gigabit networking is an effective tool for accessing data from large databases," says NREN's Marjory Johnson. "The know-how to do gigabit networking is clearly out there, but it is still very difficult to do today." Challenges remain As these new applications demonstrate the versatility of gigabit networking technology, the development of network systems continues and technical challenges remain. For example, workstation tuning and application enhancements will be necessary to take advantage of the potential increase in network bandwidth. Also, satellites such as the new Terra environmental satellite transmit an enormous amount of data to Earth on a steady basis. To distribute these large data sets across the U.S. and even the world, NASA engineers must tackle the communications challenge this problem presents. Data streams from the Terra satellite are acting as a testbed for proving advanced technologies, including gigabit networking. According to NASA's Jeff Smith, Earth Science Data and Information System network engineer at Goddard Space Flight Center, "the Terra spacecraft generates up to one terabyte of data per day. A terabyte is a trillion bytes. This enormous flood of data can be distributed to more than 500 Terra researchers only over high-performance research and education networks such as NREN. With the scheduled launch of the Aqua spacecraft in 2001, even more data are on the way. Gigabit networking is the only possible way that NASA will be able to distribute these massive amounts of Earth-observation data." What's ahead? Today the NREN Project is sharing its knowledge and experience of what gigabit networking can accomplish through technology demonstrations and important engineering developments. At the same time, the project fosters a diverse community interested in utilizing this remarkable communications technology fully.
Recently, gigabit networking experts and others interested in the technology's potential from around the U.S. gathered at an NREN-sponsored workshop at NASA's Ames Research Center. Workshop participants witnessed demonstrations of VMS and several other applications and joined discussions of what milestones need to occur over the next two years to advance gigabit networking to its next level. Right now, issues such as connectivity and how to better use computer architectures, operating systems and network interface cards in a gigabit world commanded center stage during the discussion. The experts agree that without gigabit networking technology to handle an enormous flood of information, the research community -- the scientists and engineers sharing new ideas and data over these networks -- will suffer. While delivering
gigabit capabilities to the desktop was once considered nearly impossible,
today it can be accomplished when the user taps the right kind of networking
expertise. Advancing gigabit technology in support of NASA missions, the
NREN Project team is already demonstrating that the world of super-fast
networking will soon be routine. |
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