NEWS RELEASE
May 13, 2015

NII Succeeds in Achieving One of World’s Fastest
Long Distance Transmission Speeds
Records transmission speed of 84 Gbps using new MMCFTP protocol

The National Institute of Informatics (Chiyoda-ku, Tokyo; Director General: Masaru
Kitsuregawa; “NII,” hereafter) recently conducted demonstration testing of the new protocolcalled MMCFTP (Massively Multi-Connection File Transfer Protocol) designed to enable longdistance high-speed file transmission over the JGN-X R&D testbed network operated by theNational Institute of Information and Communications Technology (Koganei-shi, Tokyo;
President: Masao Sakauchi; “NICT,” hereafter). During the testing, researchers with MMCFTP
successfully achieved the stable transmission of 1PB (Petabyte; 1PB comprises 1,000TB) ofdata at approximately 84 Gbps, one of the world’s fastest transmission speeds*1.
In fields of cutting-edge science and technology such as particle physics, nuclear fusion andastronomy, the big data obtained from large experimental systems built through international
cooperation are transmitted to and analyzed by the participating countries. While progress has
been made in the development of super-high-speed networks in the 100Gbps range for thispurpose, one of the issues faced has been limited transmission speeds during long-distancecommunications due to transmission protocol limitations. MMCFTP is characterized in that it
uses a large number of TCP connections simultaneously when transferring big data. By
dynamically adjusting the number of TCP connections established based on network conditions(round trip time and packet loss rate), stable super-high-speed data transmission has beenachieved.
The latest testing was conducted on March 27 and 28 of this year, with round-trip transmissions
taking place over the 100Gbps Tokyo – Osaka – Ishikawa segment of the JGN-X network(almost equivalent to communication distances between Tokyo and Asahikawa or between
Tokyo and Kumamoto). Researchers succeeded in transmitting an enormous 1PB of data, theequivalent of 40,000 standard 25GB Blu-ray discs, in 26 hours, 31 minutes and 55 seconds.

Communications
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This is the equivalent of transferring the contents of a Blu-ray disc about once every 2.4
seconds.
NII is scheduled to start operation of the SINET5 next-generation science information network
connecting domestic and overseas locations over a 100Gbps connection in April 2016. To
coincide with the launch, along with conducting demonstration testing in international
environments, NII will provide the MMCFTP program for the development of cutting-edge
science and technology, achieving stability and further increases in speed through actual usage.
MMCFTP will be displayed and demonstrated at NII Open House 2015, to be held June 12 and13.
[Testing Configuration]
For the test, a transmitter and receiver (both general purpose servers) set up to use MMCFTP
were installed at NICT Headquarters (Koganei-shi, Tokyo), and round-trip circuits wereconfigured with NICT’s Hokuriku StarBED Technology Center (Nomi-shi, Ishikawa Prefecture;round-trip delay time of 25.7 milliseconds), as shown in Figure 1.
The transmitter and receiver were each equipped with five 40GbE (Gigabit Ethernet) ports toconnect to a Layer 2 switch, and the Layer 2 switch has twelve 10GbE ports to connect to theJGN-X access node. This connection environment of at least 100Gbps was ensured

fortransmitting and receiving data using the link aggregation*2 feature.
The test was performed under conditions referred to as memory-to-memory*3. The
transmission time for 1PB was 26 hours, 31 minutes and 55 seconds, and transmission
occurred at a goodput*4 rate of 83.7Gbps (Figures 2 and 3).
On average 2,273 TCP connections and a maximum of 6,632 TCP connections were used, andthe average communication speed per TCP connection was 37.4Mbps. In this test, it wasdemonstrated that high-speed transmission is available with MMCFTP, as communications
traffic is mostly evenly distributed to each aggregated physical link even when a large numberof circuit lines have been combined.
MMCFTP utilizes a patent held by NTT DATA Corporation*5 as an elemental technology. NII
developed an improved version of the transmission program to enable support for super-high-Communications
Web: http://www.nii.ac.jp
Twitter: @jouhouken
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1-2 Hitotsubashi 2-chome
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speed communications and link aggregation in order to achieve the high-speed datatransmission observed in the test.
*1 One of the world’s fastest: As data transmission speed from one server to another. Based on NII’s research.
80Gbps long-distance transmission at the Super Computing 2014 international conference held in New
Orleans, USA in November last year was reported as the “world’s fastest.” Although aspects such as
distance conditions differed, the results of this test surpassed that speed.
*2

Link aggregation: A technology where multiple physical links are logically combined and treated as a singleconnection.

*3

Memory-to-memory: A test condition that measures the performance of data held in a transmitter’smemory being written to the memory of a receiver. This is best suited to measuring the performance ofa communications protocol because the reading of data from a disk and the writing of data to a disk is
not performed and communications are not limited by disk performance.

*4

Goodput: The throughput associated with only the data actually exchanged between applications, withoverhead for communications control such as retransmission and protocol headers removed (the volumeof data transmitted per unit of time)*5

NTT DATA Patent: Patent No. 5379892: File transfer method and the systems and programs thereof. NII
has obtained a license to use the patent for academic purposes. The MMCFTP program with the patent isavailable free of charge only to SINET users.

Communications
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Twitter: @jouhouken
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Figure 1: Configuration of the Test System

Figure 2: Test Results (State of Bandwidth Utilization)

Communications
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Figure 3: Test Results (Traffic Status between Tokyo and Osaka)

The above figure depicts total volume of traffic between Tokyo and Osaka. In addition to
the traffic generated by the test (including overhead such as retransmission and protocolheaders), this includes traffic from other applications.
Note – Data source for Figures 2 and 3: JGN-X NOC website (https://www.jgn-x.jp/jp/)

Communications
Web: http://www.nii.ac.jp
Twitter: @jouhouken
facebook: https://www.facebook.com/jouhouken

1-2 Hitotsubashi 2-chome
Chiyoda-ku, Tokyo 101-8430
Direct：03-4212-2164 Fax：03-4212-2150
E-Mail: media@nii.ac.jp