June 24, 2024

How Turing Award Winner Bob Metcalfe invented the Ethernet

[Video caption: Bob Metcalfe, with an inside view to the history of the Internet, gives us some insight into the principles that make it work.]

Bob Metcalfe, having just received the Turing award for his many years of technological pioneering, reflects on the Internet as it is now, and as it may soon be. It is fascinating to see him describe his life’s work: It is an amazing journey through the development of the basic technology of our time.

But according to his vision of the technological world of today, today and tomorrow, it all comes down to one word.

“Connectivity is the future,” says Metcalfe.

In talks like this one at CSAIL’s Imagination in Action, he uses the Chinese axiom: ‘if you want to be rich, build a road,’ as a precursor to the ways in which technologies such as AI are developing today, and he talks about his own ancestor, Jack Metcalfe or ‘Blind Jack’ creating possibly similar infrastructures as a civil engineer during the industrial revolution. A few hundred years later, we are at a crossroads in the development of the next generation, and connectivity will be a major priority. Consider this part of what he has to say, considering where we are headed:

“Connectivity includes moving mass, moving energy, moving signals … The most important new fact about the human condition is that we are now suddenly connected.”

In all important ways, Metcalfe saw the birth of the Internet in 1969. While working for JCR Licklider, he designed an interface called IMP #6 which was essentially a packet switch.

Then he got a front seat to many of the standards and developments that rapidly changed the Internet as it evolved, milestones such as Telnet, FTP and TCP/IP. Xerox made what some consider to be the first computer, as it turns out, in 1973, and that, along with other big changes, put an end to the search for a better network.

When you listen to him talk about the emerging Ethernet, the cabled ancestor of our modern wireless systems, he points to three very important technological creations: the vampire tap, which allowed people to change the bus technology without taking the network down, Manchester or phase encoding as a data storage system with a self-clocking feature, and the Aloha network, where repetitive packet attempts provided a way to send messages consistently.

You will hear him say that the new system was “fast” on coaxial cable, at least according to the technology at the time – about 2.94 Mbps.

We can wonder at the order of magnitude involved, as he emphasizes that this new system was not 10 times, or 100 times, but 10,000 times faster than what was in place before.

And the march through the Moore’s Law era is accompanied by the need for speed: if you had a 1400 baud modem in the ’90s, for example, think about how it uses something today.

Fast forward to 2019, when the world began to suffer from the limitations of the pandemic era.

It was a tumultuous time, and one where Metcalfe says he’s seen people quickly emulate — those who previously swore they wouldn’t use video to teach classes. According to his account, all professors at the University of Texas began to teach through videos quite quickly, which led him to adopt the tongue-in-cheek acronym COVID which stands for it, not SARS-COV-2, but, nevertheless, a collaborative video.

Moving back to the analysis of connectivity today, Metcalfe often mentions a key difference between two connections: transistors and neurons.

Is a transistor better than a neuron? In some ways, he suggests, it works better. On the other hand, where neurons are deeply connected by nature, transistors are not.

“Transformers control neurons, but … brains control computers,” he says. “This is about connectivity.”

In the CSAIL talk, Metcalfe mentioned two other pieces of technology that have interesting applications today: first, interstellar radio, where plutonium-powered space signals are sent using Manchester encoding as a protocol, and then the orders of magnitude associated with GPT networks, compared to those in the human brain.

In fact, it all depends on the ability to make connections, whether the main agents are biological synapses or digital switches.

Consider this quote from him in closing:

“I’m predicting that we’re going to get better neural nets by adding connectivity, not just fiddling around with the functions … The most striking new fact about humanity is: we’re now connected. Finally, connectivity should no longer be an add-on, in the design of our systems. … It’s not. Connectivity should be a guiding principle for design, and an organizing principle of design.”

It gives you a useful way to think about what we will be doing in the coming years, and beyond. That’s one reason why it’s so exciting to sit and listen to what Metcalfe has to say. In the exponential march of technological progress we are now – we are likely to need all the connectivity we can get.

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