Ethernet standards wonks eye up speeds beyond 400Gb/s

For now you have to cope with 100Gb/s and 400Gb/s over single-mode fiber, and brace for 100Gb/s over 80kms

The Ethernet Alliance has wrapped up its 2021 Technology Exploration Forum and revealed it’s heading off in pursuit of speeds beyond 400Gb/s.

That acceleration is in the future, however, once a newly formed study group figures out what technologies need to be built to make it possible — and whether anyone will buy even faster Ethernet.

For now, the Alliance is content to have completed and published the IEEE 802.3cu standard, which delivers 100Gb/s and 400Gb/s over single-mode fiber at 100Gb/s per wavelength. The Alliance reckons this standard matters because single fiber operations use less power, which means users can control costs and perhaps also operate denser rigs as they’ll have less heat to manage.

Ethernet aficionados who like good old-fashioned copper also have reasons to be cheerful, thanks to IEEE P802.3ck progressing to a working group ballot. Such ballots occur once a standard is considered complete and stable.

If this one succeeds, it will be important as it proposes an electrical interface for Ethernet at 100Gb/s, 200Gb/s, and 400Gb/s, reducing reliance on fiber. “This standard, when completed, is intended to enable 100Gb/s electrical interfaces and support development of higher-density or lower-cost electrical interfaces for 100, 200 or 400Gb/s Ethernet,” writes the Ethernet Alliance.

The forum also saw IEEE P802.3ct completed and advance to final pre-publication review.

The standard concerns 100Gb/s over dense wavelength division multiplexing (DWDM) systems, and is billed as “the first Ethernet specification of coherent DWDM technology supporting 100Gb/s connectivity over lengths of at least 80 kilometres.”

As DWDM runs over optical fiber, and there’s plenty of that around, the prospect of speedy comms over 80km offers interesting possibilities for disaster recovery and resilience-oriented rigs. ®