A July meeting in San Francisco could mark an historic decision point for the IEEE group trying to chart the future of Ethernet. The group is expected to propose an effort that will set standards both for 40 and 100 Gbit/second versions of the technology to meet the diverging needs of computer and communication companies.

One camp of companies including Broadcom, Hewlett-Packard, Intel and others is standing firm that computers are best served by a 40 Gbit/s standard. A separate camp including Cisco Systems and others believe core networking equipment needs an 100 Gbit/s standard.

Leaders of the so-called High Speed Study Group (HSSG) believe a compromise embracing both approaches could be the best route to breaking a logjam. HSSG has been at work for nearly a year and has to date requested two extensions of its work.

“The July meeting is an important one because each extension becomes more difficult to get and we do have to make a decision,” said John D’Ambrosia, chairman of the group and a components scientist at Force10 Networks.

“The reality is at this stage we have two camps and they have both made their positions pretty clear to each other,” D’Ambrosia said. “At this point my feeling is the study group will work toward a consensus where one group will develop both 40 Gbits/s for computers and 100 Gbits/s for core networking,” he added.

More than 100 people have been attending the group’s meetings. Traffic on the group’s reflector site has been growing.

“There could be a lot of new technologies developed out of this effort,” said D’Ambrosia.

One of the big questions behind such an effort will be how much common technology the two speed grades share. For example, it’s not clear whether a 40 and 100 Gbit standard could share one encoding scheme and one approach to optical and copper cabling.

Currently the group’s charter calls for defining a 100 Gbit media access controller that could send data over a 10-meter copper cable as well as longer optical cables. The 40 Gbit proposal includes defining a 40 Gbit backplane.

Technical proposals discussed so far have included using multiple parallel channels of optical fibre, multiple colors (called lambda) within a fibre, multiple conductors in copper cables or a combination of techniques.