Ethernet flexes network muscles

October 04, 2016 // By Rick Merritt
A new generation of Ethernet silicon is in the works that could help further spread use — especially in optical backbone networks — of the already widely adopted networking technology. Flexible Ethernet enables chips that can dial in different data rates as needed.

A preliminary spec for Flexible Ethernet at 100 Gbits/second rates was formally set by the Optical Internetworking Forum earlier this year. The OIF will fill in that spec with more details and support for 25G, 200G and 400G rates in a 2.0 effort expected to start in November.

Multiple vendors demonstrated FPGA-based implementations of the technology at optical networking events earlier this year. Support in next-generation ASICs and DSPs is said to be in the works with first products rolling next year and broad availability expected in 2018.

The technology solves several problems. Users across the complex networking landscape are finding needs for specific data rates not currently supported in standards that can take years to define. More specifically, big data center operators need flexibility to ensure they can fill up long-distance optical links, the most expensive part of their networks and the part that takes the longest to upgrade.


Verizon sketched out an early concept for Flex Ethernet. (Images: Xilinx)

In addition, large data centers need to upgrade data rates inside their networks faster than organizations such as the IEEE can roll out new standards. The IEEE will finish work next year on a 400G standard it started in 2014, but for years the Web giants have called for terabit-class Ethernet links they may need within a couple years.

“I’m hoping [Flex Ethernet] becomes the de facto MAC for beyond 400G rates,” said Tad Hoffmeister, an optical networking architect at Google. “I expect a small rollout over the next couple years, but by 2018-19 with next generation DSPs and router silicon support it could really take off,” he said, speaking at an Ethernet Alliance meeting.

Several chip makers are starting to make commitments to support Flex Ethernet. Merchant suppliers of DSP specialized for optical networks include Acacia, Clariphy and NTT Electronics. Systems makers such as Cisco, Nokia and Huawei are also expected to support the capability in chips they design for their switches and routers.