IEEE group settles on faster Ethernet plans

IDG News Service - A technical group working on the next generation of Ethernet has agreed to disagree and will now work on a single standard that covers both 40Gbit/sec. and 100Gbit/sec. speeds.

The Higher Speed Study Group (HSSG), part of the Institute of Electrical and Electronics Engineers Inc. (IEEE), made the decision last week at its meeting in San Francisco after months of debate between backers of the two speeds. If the IEEE approves the move late this year as expected, a standard may be completed by mid-2010, said HSSG Chairman John D'Ambrosia.

Ethernet has sped up by a multiple of 10 several times, from 10Mbit/sec. to 100Mbit/sec. and from 1Gbit/sec. to 10Gbit/sec., the current fastest version. Some HSSG members backed a similar boost this time, and that 100Gbit/sec. plan appeared to have won out late last year. But others pushed for a 40Gbit/sec. standard.

Different applications were at the heart of the disagreement, according to D'Ambrosia. The need for speed is growing everywhere, but at different rates. While the data output of servers doubles roughly every 24 months, the amount of traffic on carrier networks is doubling every 18 months, D'Ambrosia said. Members more interested in faster server-to-switch applications pushed for a 40Gbit/sec. goal, while those aiming at network aggregation and backbones favored 100Gbit/sec. The higher speed means more expensive and power-hungry equipment.

"I wouldn't say there was a fight. I would say there was an education going on, and it got heated at times," D'Ambrosia said.

Now a single standard, to be called IEEE 802.3ba, will include specifications for both speeds. Each will offer a selection of physical interfaces: There will be specifications for 40Gbit/sec. links up to 1 meter long for switch backplanes, 10 meters for copper cable and 100 meters for multimode fiber. For 100Gbit/sec., the group will standardize 10-meter copper links, 100-meter multimode fiber links, and 10-kilometer and 40-kilometer distances on single-mode fiber.

It's the first time an Ethernet standards task group has pursued two speeds in one standard, according to D'Ambrosia. "One size doesn't fit all, in this case," he said.