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Bob Metcalfe Receives Industry’s Highest Honor for Ethernet Creation

Bob Metcalfe

Bob Metcalfe, professor emeritus in the Chandra Family Department of Electrical and Computer Engineering at The University of Texas at Austin, was named the recipient of the 2022 Association for Computing Machinery (ACM) A.M. Turing Award for the invention, standardization and commercialization of Ethernet.

The ACM A.M. Turing Award, often called the “Nobel Prize of computing,” includes a $1 million prize, with financial support provided by Google, Inc. The award is named for Alan M. Turing, the British mathematician who articulated the mathematical foundations of computing.

"It is dangerous to accept an award for developing Ethernet, which turns 50 on May 22, 2023,” Metcalfe said. “Over Ethernet's 50 years, hundreds of people have earned some claim of inventorship. Join me in saying to these folks, ‘Thank you.’

Before retiring from UT Austin in 2021, Metcalfe led innovation initiatives in the Cockrell School of Engineering and across campus for a decade. He is the founding director of the Texas Innovation Center, which launched in 2011 to help faculty and students bring their scientific and engineering discoveries to market. He envisioned helping Austin become a better version of Silicon Valley.

“Bob has made several important contributions to the tech industry. His invention of Ethernet revolutionized how everyone interacts with computers and each other,” said Roger Bonnecaze, Dean of the Cockrell School of Engineering. “This prestigious award is very well-deserved indeed!”

During his time at UT, Metcalfe was a fixture as a speaker and advisor for entrepreneurial groups and events across campus. He was a major part of Longhorn Startup, a fall course that gives students an opportunity to hear from entrepreneurs and then pitch their own projects. And he created a startup studio and salons within the Cockrell School to help professors and students sharpen their startup ideas.

“We are proud and honored to have Bob as our colleague and for the Chandra Family Department of Electrical and Computer Engineering to be home to the winner of the Nobel Prize of computing,” said Diana Marculescu, department chair of the Chandra Family Department of Electrical and Computer Engineering at UT Austin.

Invention of Ethernet

In 1973, while a computer scientist at the Xerox Palo Alto Research Center (PARC), Metcalfe circulated a now-famous memo describing a “broadcast communication network” for connecting some of the first personal computers, PARC’s Altos, within a building. The first Ethernet ran at 2.94 megabits per second, which was about 10,000 times faster than the terminal networks it would replace.

Although Metcalfe’s original design proposed implementing this network over coaxial cable, the memo envisioned “communication over an ether,” making the design adaptable to future innovations in media technology including legacy telephone twisted pair, optical fiber, radio (Wi-Fi), and even power networks, to replace the coaxial cable as the “ether.” That memo laid the groundwork for what we now know today as Ethernet.

“Ethernet is the foundational technology of the Internet, which supports more than 5 billion users and enables much of modern life,” added Jeff Dean, Google Senior Fellow and SVP of Google Research and AI. “Today, with an estimated 7 billion ports around the globe, Ethernet is so ubiquitous that we take it for granted. It’s easy to forget that our interconnected world would not be the same if not for Bob Metcalfe’s invention and his enduring vision that every computer needed to be networked.”

Metcalfe’s Ethernet design incorporated insights from his experience with ALOHAnet, a pioneering computer networking system developed at the University of Hawaii. Metcalfe recruited David Boggs, a co-inventor of Ethernet, to help build a 100-node PARC Ethernet. That first Ethernet was then replicated within Xerox to proliferate a corporate internet.

In their seminal 1976 Communications of the ACM article, “Ethernet: Distributed Packet Switching for Local Computer Networks,” Metcalfe and Boggs described the design of Ethernet. Metcalfe then led a team that developed the 10Mbps Ethernet to form the basis of subsequent standards.

"Ethernet was the plumbing upgrade the Internet needed in the 1970s,” Metcalfe said. “Ethernet enabled the transition from Arpanet, a network of time-shared computers servicing dumb terminals to an internetwork of personal computers, their servers, and routers.”

Standardization and Commercialization

After leaving Xerox in 1979, Metcalfe remained the chief evangelist for Ethernet and continued to guide its development while working to ensure industry adoption of an open standard. He led an effort by Digital Equipment Corporation (DEC), Intel, and Xerox to develop a 10Mbps Ethernet specification — the DIX standard. The IEEE 802 committee was formed to establish a local area network (LAN) standard. A slight variant of DIX became the first IEEE 802.3 standard, which is still vibrant today.

As the founder of his own Silicon Valley Internet startup, 3Com Corporation, in 1979, Metcalfe bolstered the commercial appeal of Ethernet by selling network software, Ethernet transceivers, and Ethernet cards for minicomputers and workstations. When IBM introduced its personal computer (PC), 3Com introduced one of the first Ethernet interfaces for IBM PCs and their proliferating clones.

Today, Ethernet is the main conduit of wired network communications around the world, handling data rates from 10 Mbps to 400 Gbps, with 800 Gbps and 1.6 Tbps technologies emerging. Ethernet has also become an enormous market, with revenue from Ethernet switches alone exceeding $30 billion in 2021, according to the International Data Corporation.

Metcalfe insists on calling WiFi by its original name, Wireless Ethernet, for old times’ sake.

“Ethernet has been the dominant way of connecting computers to other devices, to each other, and to the Internet,” explains ACM President Yannis Ioannidis. “Metcalfe’s original design ideas have enabled the bandwidth of Ethernet to grow geometrically. It is rare to see a technology scale from its origins to today’s multigigabit-per-second capacity. Even with the advent of WiFi, Ethernet remains the staple mode of data communication, especially when security and reliability are prioritized. It is especially fitting to recognize such an impactful invention during its 50th anniversary year.”

Metcalfe will be formally presented with the ACM A.M. Turing Award at the annual ACM Awards Banquet, which will be held this year on Saturday, June 10 at the Palace Hotel in San Francisco.

Metcalfe graduated from MIT in 1969 with Bachelor degrees in Electrical Engineering and Industrial Management. He earned a Master’s degree in Applied Mathematics in 1970 and a PhD in Computer Science in 1973 from Harvard University.

Metcalfe recently became a Research Affiliate in Computational Engineering MIT’s Computer Science & Artificial Intelligence Laboratory.

Metcalfe’s honors include the National Medal of Technology, IEEE Medal of Honor, Marconi Prize, Japan Computer & Communications Prize, ACM Grace Murray Hopper Award, and IEEE Alexander Graham Bell Medal. He is a Fellow of the US National Academy of Engineering, the American Academy of Arts and Sciences, and the National Inventors, Consumer Electronics, and Internet Halls of Fame.