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Source: http://www.gcn.com/print/27_14/46470-1.html#

Author: William Jackson

The Energy Department’s Energy Sciences Network is growing with increased bandwidth demands. The latest generation of the network, ESnet4, is a 100 gigabits/sec optical network; the department has projected that it would require 200 gigabits/sec by 2014.

The ESnet backbone is provided by Internet2 and Level 3 Communications, and its bandwidth is achieved by aggregating 10 gigabits/ sec optical channels. Increasing the size of the common interface can easily increase available bandwidth on existing fiber optic cable.

“Before they use up their capacity, we will be ready with the next generation technology,” said Randy Brogle, senior director of Level 3’s research and education division.

The next wave of interfaces will work at 40 gigabits/sec, and a number of commercial networks already are moving to that technology rather than bundling 10 gigabits/ sec channels.

“We’ve had a 40 gigabit capability since 2007,” said Paul Gainham, marketing director for Juniper Networks’ service provider division in Europe, Africa and the Middle East. “It’s a relatively new technology.”

In the United Kingdom, cable operator Virgin Media recently tested a 40 gigabits/ sec link between two major routing nodes on its Nortel optical network. “We provided a 40 gigabits/ sec interface at each end of the link.” Those interfaces are supported by Juniper T640 routers, the same routers used on Internet2, as well as the TX Matrix multiterabit routers.

In the United States, Verizon Business deployed 40 gigabits/sec router-to-router links last year, beginning with a Washington-to-Chicago Internet route and another route on the company’s Multiprotocol Label Switching network between Washington and New York City. Using a single 40 gigabits/sec channel rather than aggregated links provides better performance with less latency.

“For some, aggregating channels will continue to be a viable option,” Gainham said, but 40 gigabits/sec will become more attractive as the price for the technology comes down.

Not too far down the road, vendors expect to have 100 gigabits/sec interfaces, which will be able to provide 800 gigabits/sec in aggregated pipes. How long before 800 gigabits/sec is not enough? That’s difficult to say, said Rob Vietzke, executive director of network services for Internet2. “We’re interested in 40 [gigabits/ sec] and 100 [gigabits/sec] interfaces now.” Before that capacity reaches its limit, there will be a lot of work done with bandwidth management to expand the capacity of existing pipes.

Internet2 is a test bed network for new technologies and applications, and in many ways, it is growing in a different direction from the commercial Internet, said William Johnston, head of ESnet at DOE’s Lawrence Berkeley National Laboratory.

“I believe that research and education networks will always have different characteristics than commercial networks,” he said.