From Tinkering to Teaching: Doug Comer's Journey to Internet Pioneer

May 20, 2021
Doug Comer
By Dan Rosenheim

One might be forgiven for thinking that, as a boy, Doug Comer had little chance of becoming one of the world’s premier experts in computer networks and a renowned university teacher.

The son of a welder father and an elementary school teacher mother, Comer grew up in farm country, near the town of Vineland in southern New Jersey, in a family where “having an education” meant graduating high school.

But Comer possessed a native curiosity about the mechanics of things that, combined with inspiring high school classes in physics and mathematics, gave birth to an early and abiding passion for math and science.

“I liked to see how things worked,” he said in a video interview. “I wanted to know what was inside, what made them tick.”

His curiosity led to simple carpentry and basic machinery, then quickly evolved into an interest in electronics.

“You know, it was the typical blue collar stuff, and it was fun,” Comer said.
“By the time I got to high school I had sort of understood electricity -- how to wire up lamps and do house wiring and things like that.

“My parents didn't have a lot of money so I didn't buy a lot of electronics,” he continued. “People would give me old radios and televisions, I would take them apart, see how I could use the pieces. I made a working TV by hooking together pieces from multiple other televisions. It wasn't pretty, but it worked.”

Comer’s nascent interest in science got a huge boost when his high school hired two math teachers with PhDs and, lacking a physics teacher, brought in a retired physicist from the Oakridge National Laboratory in Tennessee.

“It was absolutely fantastic,” Comer said. “The physics teacher really understood physics, could answer any question. And with the math teachers I thought, wow, mathematics is just like physics -- it’s a wonderful field.”

When his teachers urged him to attend college, he leapt at the chance to keep learning, though not without some resistance at home.

“No one in my family had ever gone to college, and my father was skeptical -- he never really liked college people,” Comer said. “My mother supported the idea, but my parents were very religious, so finally they sent me to Houghton College in upstate New York, which had strong ties to the Wesleyan Church.”

There, along with attending chapel services every day, Comer built on his high school experience, majoring in science and math. And while he was at Houghton, the school got its first computer, an IBM 1130.

“It was so small, you can’t even imagine,” he said. “It had a disk of 512,000 bytes -- not gigabytes, not megabytes. Five hundred and twelve thousand bytes. “But,” he added, “a computer combines electronics and mathematics all in the same box.”

So a fascinated Comer asked the head of the math and science division for permission to access the computer on nights and weekends when it wasn’t in use, and he was given a key.

“I got what very few people had in those days -- the chance to sit and learn a whole lot of computing,” he said. “Wow.”

After graduating from Houghton in 1971 and completing a doctorate in computer science at Penn State in 1976, Comer found himself confronting a stark career choice between the private sector and remaining in academics.

Bell Labs, arguably the best industrial research lab of the day, made an attractive pitch for Comer to come work in its Murray Hill, New Jersey, headquarters.

But at roughly the same time, two recruiters from Purdue University heard Comer deliver a highly theoretical paper about a hot topic of the day: NP completeness. In its simplest sense, Comer’s paper showed that using a computer to solve a common problem in databases would take as long as solving seemingly more complex mathematical problems.

“It was very unusual because students didn’t give papers at major conferences in those days,” Comer said. “Right after the presentation, these guys came up to me and said, ‘We want you at Purdue.’ 

Comer loved teaching about computers, so it was an easy choice; he headed to Purdue, beginning a career at the school that has lasted 45 years and counting.

“I never regretted my choice,” Comer said. “If you look at the people who go commercial, they have to sell their souls. They get in the habit of pitching to venture capitalists and everything is overstated. I like science because I can deal with facts.”

In his time as an academic, Comer has compiled a truly remarkable string of accomplishments. His trailblazing work on TCP/IP has brought him international acclaim, including recent induction into the Internet Hall of Fame; his books on computer architecture and on networking are widely used in classrooms worldwide, having been translated into at least 16 languages; and, for more than 20 years, he edited the distinguished trade journal “Software: Practice and Experience.”

Even as an academic, however, Comer has never let go of his hands-on, blue-collar roots.

“At the journal, we wanted people to submit papers who had actually built software, probably because my father was so skeptical of college-educated people who didn't know what they were doing,” he said. “I've always been somewhat disappointed in colleagues who write academic papers without actually building things themselves.”

Early on in his time at Purdue, Comer created a simple network of small computers at Purdue, using a bunch of tiny process computers, each with 8K bytes of memory.

“Here’s where my electronics background came in,” he said. “These little computers had serial lines, and I knew how to solder. So I soldered all the wires together, built a little network and figured out how to send messages around it.”

After building a tiny network, the next step was to join a project to allow data sharing between computer science departments at multiple universities, starting with Purdue and the University of Wisconsin. 

An initial grant request was turned down by the National Science Foundation. “But then the Defense Department’s Advanced Research Projects Agency said it would support the project if it included a new approach it was developing called an Internet, which would be based on TCP/IP protocol technology,” Comer said.

“So, because I had built this little toy network in the corner, the head of my department picked me to be the protocol expert. I’d never had a course in networking, I hardly knew what protocols were, but they figured I knew more than anyone else so they told me to read up and get ready.’”

Comer established a way for Computer Science departments to communicate by creating a pioneering process called tunneling, an approach that subsequently became widely used on the Internet.

Even as an author, Comer began with a hands-on approach, taking it upon himself to phototypeset with an old-fashioned typesetter on photographic film.

When sales of his Internetworking textbook took off, Comer was inundated with requests for consulting -- not just from tech companies such as Cisco and IBM, but from Merck, Eli Lilly, RR Donnelley and many others. So his career has included sabbaticals, some of them extended, to work with tech companies and to establish the Interop Graduate Institute.

But while his research has brought him renown -- and remuneration -- Comer has remained just as devoted to his work in the classroom, where students consistently rank his teaching at the top of the department. 

“I have had the pleasure of going into classrooms and telling students about the most interesting stuff on the planet,” Comer said. 

As he nears the end of a fifth decade at Purdue, Comer continues to teach, write and consult.

When he’s not working, he enjoys -- always the hands-on man -- fixing things up in the house and doing some woodwork. He and his wife, Christine, his college sweetheart, have traveled widely across the world, which he notes, while not uncommon these days, is quite a change from his childhood when just going to a neighboring state was a big deal.

“When I moved to Indiana, my Dad drove out here from New Jersey,” Comer said. “It was the farthest he had ever been from home.”

Indeed, Comer is well aware of the contrast between his upbringing and his accomplishments. “I don’t want this to sound egotistical,” he said, “but it’s been an absolute skyrocket up, considering where I came from and the people my parents associated with. When you start in that world you don’t think about the one I live in now.”

And the world Comer lives in now continues to be a source of excitement and promise, despite concerns about the downside of digital technologies. 

“At first people worried about pornography on the Internet, and now they worry about cyber attacks from foreign countries,” he said, “but I think we’ll realize the good things on the Internet outweigh the bad.”

“Sure, it’s changing the world, but you can also say that about the printing press and the automobile. It’s the nature of technology that it can be used for good or evil.

“And I’ve always had this feeling that there are far more good people than evil, and in the end the things people made get used for good.”

Dan Rosenheim was managing editor of The San Francisco Chronicle and vice president/news for KPIX-TV. Retired from full-time work, he is currently business development director for Bay City News and