Scientists, Start Your Engines
By Carla Garnett
On the Front Page...
NIH recently opened a new on-ramp to the next generation Internet (NGI) via a high-speed (155 Mbps, or millions of bits per second) connection to the very high performance Backbone Network Service (vBNS). Launched in 1995, the vBNS is a nationwide network supporting high-performance, high-bandwidth research applications and is the product of a 5-year cooperative agreement between MCI and the National Science Foundation.
The vBNS was designed for the scientific and research communities and originally provided high-speed interconnection among NSF supercomputing centers and connection to NSF-specified network access points. Currently, the vBNS connects NSF supercomputing centers and research institutions that are selected under the NSF's high-performance connections program.
Speed It Up a Little More
Paving the way for the new ramp took a bit longer than anticipated, according to the NLM team that helped broker the various agreements to get vBNS access for NIH.
"NIH's application broke ground in that we were the first government site to go through the process of applying to become attached to the vBNS as just a site," explains team member Mike Gill, a network engineer with the Communications Engineering Branch of NLM's Lister Hill National Center for Biomedical Communications. Various federal networks including the Department of Energy's ESNET and NASA's NREN already connect to the vBNS, but NIH was the first federal site that is not also a nationwide network.
One requirement of the application was that NIH needed to be invited to join by a university. Dr. Richard Ewing, dean of science at Texas A&M University, extended the invitation.
Future frontiers for the enhanced connectivity environment of the vBNS are limited only by the creativity of its users. Gill and other team members hope the new capability will spur application development (see sidebar, Putting Speed to Good Use). Also, an evaluation of access to multimedia (text and digital x-ray) databases is under way.
The vBNS is already being used with great success to access NLM databases, although the degree of success depends on the connection at the endpoints, known as the "last mile" problem, and the computer and network setup at both ends of the connection.
"As fast as the vBNS is, it can be limited just like the 'regular' Internet in this way," Gill said. "However, with institutions also equipped with 155 Mbps access to the vBNS, we can expect higher transfer rates. Things that were not practical before are now practical."
Joe Mambretti, director of the International Center for Advanced Internet Research at Northwestern University, agrees the possibilities generated by the increase in speed are unlimited. "This could be the subject of a very large paper," he says. "One example may be digital video. The traditional Internet does not do video well. It is essentially a text and image medium. The video that is there consists of small, grainy, jittery images. With our current next generation infrastructure, we can do full-motion, full-color, full-screen video with CD-quality audio. Increasingly, we are seeing demos of very high resolution images also. The more information in the image, the higher the quality and resolution. [More and more] these networks are used for 3D imaging. Also, with the advanced network it is possible to access large amounts of research data, for example, for longterm studies of numerous medical records."
How're We Doing?
A study is planned for measuring the response time of accessing NLM information from remote vBNS locations and collecting other performance data about the network paths between NLM and the remote sites, according to Gill. The work is being done in two phases: phase I, which involves a limited number of vBNS sites, is designed to implement and test the tools and methodologies needed. Phase II will attempt to collect more extensive data among a larger group of institutions that may represent the biomedical community in vBNS.
"We are measuring a number of network performance parameters between remote sites in vBNS and our web servers and other hosts at NLM," explains Victor Cid, an NLM visiting scientist from the University of Chile in Santiago who is coordinating the evaluation. "Performance measurements are currently being obtained from computers at Yale University, University of Maryland at College Park, University of Washington, University of Illinois at Chicago, University of Southern California, Texas A&M University and UCLA. In the future we may be also testing from other locations. One set of experiments measures the time it takes to access web pages from our web servers at NLM and retrieve some large data sets. We are also measuring a number of other technical parameters such as network delay, communications anomalies, maximum data throughput, performance variation over time, and so on. We are running similar tests from computers at NLM to the same remote locations to study network asymmetries."
Additionally, they are using performance data obtained through other metric efforts within vBNS and the Internet, such as the Advanced Network & Services' Surveyor project, he says. A special network setup will allow them to perform the same set of experiments through both the vBNS and the current Internet (called the commodity Internet).
"We expect to obtain data that will give us a reasonable estimation of the performance perceived by current NLM users when they access our information services through vBNS. The data will also allow us to explore some overall performance characteristics and some of the potentials of this high-bandwidth network."
The benefit of such testing is two-fold, Cid points out. Not only will it tell developers how well the new on-ramp is working, but it may also reveal new ways to get the most out of both the vBNS and the commodity Internet. In addition, establishing vBNS connections here keeps NIH on the cutting edge of high-speed computer communication.
"vBNS is an experimental network, a 'test-bed' to study and develop future networked applications and new network technologies," Cid concludes. "The current Internet has been often plagued with communications delays and other problems. What we learn from vBNS may help us improve the Internet and teach us how to use it better. NLM and NIH have become very dependent on the Internet for different scientific and non-scientific purposes. NIH's participation on vBNS is a natural step towards an increased involvement of our community on the evolution of Internet and other related communication technologies."
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