The new dynamic is forcing network engineers to consider starting work on a terabit Ethernet standard before they have finished the 100 Gbit spec. It's also got them scratching their heads about how they will get paid for their efforts.

The pressure has become so intense a network engineer for the popular Facebook Web site said his company has considered building its own network equipment while it waits for vendors to deliver boxes that go beyond today's 10G Ethernet speeds.

"One of our top network customers said they need to spend 30 to 60 percent more on capex but their revenue is only growing three percent a year," said a senior engineering manager with Cisco Systems, speaking at an open forum hosted by the Ethernet Alliance here. "The whole industry economics are changing," he said.

A senior engineer from Deutsche Telekom agreed that bandwidth needs are growing much faster the revenue. He called for a terabit Ethernet effort to start soon, and said he is also managing initiatives to drive down the cost of line cards and other network components.

Donn Lee, a network engineer for Facebook (Palo Alto, Calif.), said his company's rapidly expanding network could use multiple 100G Ethernet systems today if he could get his hands on them. The standard is in a late stage of being finalized by the IEEE 802.3ba group.

Bandwidth requirements more than double every year for the cluster aggregation network in Facebook's data centers, Lee said. The clusters are used to compute data for the estimated 300 million users of the free Web service.

"Anybody in the top 25 Web sites has this problem," said Lee. "We are so busy building out networks, we don't have time to do these presentations," he told an audience of more than 100 network systems and component engineers.

"A 16 terabit switch would be ideal, but it doesn't exist today," Lee said. "The biggest switch I can buy today handles about two terabits," he said.

Facebook has considered making his own high bandwidth switches out of off-the-shelf parts. He called on developers at the meeting here to start work on a terabit Ethernet standard immediately.

"I would be happy if a 400G or a terabit effort would start today because the work takes four years," Lee said. "We started today's 100G effort too late, though part of that was the fault of the dotcom bust," he added.

Indeed, "the industry lost a whole generation of good technology due to the dotcom bust," said the Cisco engineering manager.

Unfortunately cost is as important as speed. "You know we offer a free service—it's all funded by advertising—so cost is paramount to stay in business," Lee of Facebook said.

The meeting was one of three industry gatherings this year discussing the need for technology beyond 100G Ethernet, said John D'Ambrosia, chairman of the 40/100G Ethernet standards effort and host for the Ethernet Alliance meeting.

The Optoelectronics Industry Development Association hosted a separate meeting on the subject earlier this year and plans another roundtable in December. OIDA also plans to ask for U.S. government funds to accelerate development of next-generation networking technology, D'Ambrosia said.

Chris Cole, an engineer with Finisar, presented his ideas on an evolutionary approach to a 400G Ethernet standard. A terabit technology would require new and complex modulation schemes and other advanced techniques, he added.

About a third of those attending the meeting said they would support work on a 400G Ethernet standard. Less than half as many said they would support work on a terabit spec.

The industry lacks the human capital to tackle both efforts at once, said Steve Trowbridge, a top technologist at Alcatel-Lucent. "The same set of experts is needed for both," he said.