Voices of Ethernet | David Cunningham

This is part of the video series The Voices of Ethernet

“Ethernet has been created by lots of contributors who all probably saw what was happening from a different point of view,” David Cunningham said. “We’ve all worked on different parts of the standard at different times.”

Cunningham’s personal point of view is unusually comprehensive. In more than two decades of work in local and metro area network standardization, Cunningham contributed to some of the most important milestones in and even beyond Ethernet’s evolution.

His entry into the technology space was “probably a little more accidental,” he said. Cunningham is a laser expert who did his PhD work in spectroscopy. In 1987 he joined Hewlett-Packard at its laboratories in the United Kingdom and was tasked with helping develop a physical layer for a Gigabit-speed network using single-mode optical fiber.

“For my success, I got assigned to work on the FDDI (Fiber Distributed Data Interface) standard,” he said. “… I didn’t really know about multimode fiber, and I certainly didn’t know about transmission over copper twisted pair.”

This led to Cunningham’s engagement with the IEEE 802.3 Ethernet Working Group. He remembers having to be kept “calm in the technical meetings because they could be very frustrating. I was young and argumentative, and sometimes I thought that the solutions weren’t very good.”

Indeed, Cunningham ended up doubling down, contributing in two sets of technical meetings to create standards for 100 Megabits per second (Mbps) over copper when the two efforts were separated: IEEE 802.3’s approach based on Carrier Sense Multiple Access with Collision Detection (CSMA/CD) media access control vs. IEEE 802.12’s Demand Priority access method. “It was awkward, to say the least,” he said.

Cunningham persevered and was recognized for contributing to IEEE 802.12, IEEE 802.3z Gigabit Ethernet, IEEE 802.3ae 10 Gigabit Ethernet and IEEE 802.3aq 10GBASE-LRM. Over the years, Cunningham’s youthful frustration gave way to a profound respect for the collaborative process among Ethernet’s huge, global cast of co-creators. Among the most important lessons Cunningham learned along the way, he said, “was to listen to what the other views are and really, truly try to understand what they are. It’s extremely easy—especially when you’re young—to get entrenched in your own ideas.

“Ethernet is based on—it’s a good thing, but it’s difficult to cope with—individual contributions. Companies can’t just walk in and take over. Everyone is expected to be an individual contributor, and all of the ideas have to be worked through in a fair and reasonable way. In the end, it’s very difficult because it’s quite likely that not all of your ideas are going to be accepted… You get some of what you helped to invent into the standard but almost always never all of it.”

That process, Cunningham feels, is fundamental to Ethernet’s remarkable success and ongoing vitality.

“There’s collaboration within standards—at least among individual experts from different companies, if not formally between the companies,” he said. “Then, once the standard is done, they all go off and make their products and try to sell their products faster than the others. The standard standardizes certain things, but it doesn’t standardize everything. So there are always features that different companies can add and different parts of the market they can focus on and define where they can be good. In doing that they learn what customers want and the next thing the customer needs, which usually then sparks off the next version of Ethernet.”

Today, Cunningham continues to follow the technology’s evolution. He marvels at the challenges of potentially achieving 800 Gbps and even 1.6 Terabit per second (Tbps) Ethernet networking. “I’m very intrigued… It’s going to be very interesting to see how that gets done.”