Nuclear physicists have built a native 10 Gigabit
Ethernet network linking Switzerland and Japan. The 18,500km Lan
crosses 17 time zones, as it follows fibres through Amsterdam,
Chicago and Seattle.
Tokyo University's Grape-DR project is using data reservoirs at
each end to optimise large TCP data flows across a long fat pipe.
They aim to get standard Ethernet working end-to-end, without the
need to convert to other protocols for the Wan section or drop to
lower speeds.
So far, the network has achieved unprecedented speeds of 9gbps
in testing between groups of Xeon servers, and 7gbps for a single
TCP packet stream between two servers equipped with Gigabit TCP
offload adapters.
High speed networks are needed so physicists around the world
can work on data generated by projects such as the upcoming Large
Hadron Collider at CERN in Switzerland. As they build them, network
engineers are learning how to configure standard TCP to run better
over long distances.
"Currently, long-distance very high-bandwidth communication is
very expensive and hard to fully utilise. If we solve these two
problems, how to use high-speed network will drastically change in
both business and technology," said Professor Kei Hiraki of Tokyo
University.
The researchers used 10 Gigabit Ethernet Wan PHY technology to
extend a Lan in Tokyo to include computers at CERN, allowing a
Japanese data analysis centre to work on CERN-generated data.
"It is exactly similar to Lan except for latency from user point
of view," said Professor Hiraki. "The importance of Wan PHY
technology is mainly cost for equipment at end nodes and
intermediate points. For example, MAC chip and optical modules as
well as controlling software are much less costly."
The main problem for 10 Gigabit is server connection - plenty of
switches support it, but it is just too fast for today's servers to
process. The solution chosen by the Tokyo team is to use TCP
offload adapters from Chelsio Communications, which relieve the
host server from needing to process Ethernet packets.
"We're implementing TCP in hardware," said Chelsio's marketing
director Randy Smith. "We can provide incredible flexibility in how
you configure TCP and the headers, windows size, and so on, to
target the protocol to your environment. The key here is we were
able to pace the traffic, so they were able to transmit a sustained
7gbps for seven hours."
Chelsio's cards cost $2000 (£1,087) to $4000 each. "Per port, 10
Gigabit is still about 10 times the cost of Gigabit," Smith said.
"But it's Ethernet so we will drive the cost out of it fast. 10
Gigabit will get to copper in a year or two."
He added that the ability to run full speed Ethernet at distance
of up to seven miles is key for the development of metro
Ethernet.
"We will see a big move next year for one to 10 Gigabits on the
research side next year," he said. "We'll also see it move into the
enterprise, and in storage networks and Nas as well as high
performance computing."
Bryan Betts writes for Techworld.com