Japan's National Institute of Advanced Industrial Science and Technology (AIST) last week sent data between PC clusters in Japan and the U.S., a distance of more than 10,000 kilometers, at 707M bps (bits per second), a record speed over such a long distance, it claimed. The speed was achieved during AIST's grid computing system field test, which integrated seven PC cluster systems, a total of 190 PCs.

In addition to AIST, PC clusters were placed at Japan's High Energy Accelerator Research Organization (HEARO) in Tsukuba, Japan; the Tokyo Institute of Technology and Tokyo University in Tokyo; Indiana University, in Bloomington, Indiana; San Diego Supercomputer Center, in La Jolla, California, and a venue in Baltimore, Maryland where the annual SC2002 supercomputer conference was held between Nov. 16 and 22.

For the field test, Tokyo Institute of Technology's PC cluster generated a large amount of scientific data to be distributed to other PC clusters for back-up copying and processing. The PC clusters each copied several hundred gigabytes of data and then simultaneously processed about 18T-bits of data.

Integrating seven PC clusters located both in the U.S. and Japan, separated by a distance of over 10,000 kilometers, and then using a single application to send large volumes of data via multiple TCP (Transmission Control Protocol) streams across the Pacific Ocean has never been done before, according to AIST.

In March 2000, Microsoft Corp. announced that it had set a record by using multiple TCP streams to send data at 831M bps over a distance of 5,626 kilometers between Redmond, Washington, and Arlington, Virginia. However, because of the different distances and volume of data exchanged, it is difficult to make comparisons between AIST's field test and past records, AIST said.

Over an optical fiber network, it takes about 0.2 seconds for a packet of data to make the 10,000-kilometer journey and an acknowledgement to return. The size of data packets is typically limited to 64K bytes by TCP's initial window size. Because there is a 0.2-second lag each time a packet of data is sent, only 320K-bytes of data can be sent per second in a single data stream, meaning a conventional Internet connection can only offer a data transmission speed of 2.56M bps, according to AIST.

By conducting parallel data transmissions between the clustered PCs, AIST accelerated the data transfer speed, it said in a statement. Data in the experiment traveled across a number of high-speed networks, including two set up by the TransPAC (Trans-Pacific) consortium, set up by universities and research institutes in the U.S. and the Asia-Pacific region to establish broadband Internet connections between the U.S. and Asia Pacific. By using two of TransPAC's networks between the U.S. and Japan, AIST was able to double the data transmission speed, it said.

Data generated at the Tokyo Institute of Technology traveled across SuperSINET, an optical fiber network established by the Japanese government for research, to Tokyo University and HEARO. From HEARO, data was sent to a relay station in Chicago via a network system of the Energy Sciences Network in the U.S., which connects high energy physics-related research laboratories around the world.

AIST was connected via Tsukuba WAN, which is used for supercomputing and high-volume database projects within laboratories in Tsukuba, to a relay station in Tokyo. From Tokyo, data traveled across two TransPAC networks, one going to a relay station in Seattle, the other going to Chicago. From the three relay stations, one in Seattle, two in Chicago, data was distributed to Indiana University, San Diego Supercompu Center, and the SC2002 venue, which was connected via SCinet, a network built during the conference.

» posted by ITworld staff

IDG News Service

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