At a gathering organized by the Ethernet Alliance here, representatives from a broad range of companies including Brocade, Broadcom and Cisco Systems said they feel the need for serial standards beyond today's 10G links. About half the group of more than 100 engineers here said they would support 25G standards efforts in an informal poll.

Scott Kipp, a technologist in the CTO office of Brocade, called for a 25G effort to enable future ASICs with terabit/second throughput. Today's ASICs are limited to about half that throughput because chip packages only allow about 48 channels of 10G each, he said in the video below.

Ali Ghiasi, a chief architect for optical systems at Broadcom disagreed. Today's 10G chip interfaces have plenty of headroom to get to Tbit throughput chips before 2015. However, the 25G interfaces will be crucial to enable faster systems plugs that will be needed for 40 and 100G Ethernet much sooner.

Joel Goergen, chief scientist at system maker Force10 Networks, said system backplanes will need to go beyond a terabit/s by 2011 and even hit 2 Tbits/s by 2015. That will require 25G links, he said.

The good news is Optical Internetworking Forum has been working about two years on a 25G standard and may have a year of work before the spec is complete, said David Stauffer, chair of the working group on the project.

"We are at the point where we have [shown] feasibility" for short-range specs that may require some decision feedback equalization, he said. "We are balloting, but how long that takes is variable," he added

However, the OIF work does not define a full physical layer spec, said John D'Ambrosia, chairman of the IEEE P802.3ba standard and host for the meeting. In a straw poll, D'Ambrosia took of attendees about 50 said they would support a 25G chip-to-chip effort and about 30 said they would support 25G cabling and backplane efforts.

"We'll talk about gathering like minds to move these ideas forward," D'Ambrosia said.

As much as a year is typically spent gathering informal consensus to generate new Ethernet standards. The Alliance meeting was an effort to accelerate the process for a host of specs needed to serve pending 40/100G Ethernet standards and even higher speed ambitions in the works.