The son of Austrian immigrants, Leonard Kleinrock grew up in New York City. At age 7, he scrapped together found materials to build a crystal radio. “I could hear music through the earpiece,” he says. “It was magic. I was hooked.” More than 25 years later, in UCLA’s Boelter Hall, Kleinrock and one of his software developers sent the first-ever computer-to-computer message, and the Internet was born. Today, with a $5-million gift given in his honor by Sunday Group Inc., a Las Vegas-based software company, Kleinrock is establishing the UCLA Connection Lab to foster interdisciplinary research on network technology, wireless systems, cryptography, blockchain, big data, artificial intelligence, machine learning and the “Internet of things.”
Tell us about that first crystal radio.
In the centerfold of a comic book, I found the directions for building it with parts I could find around the house: an empty toilet-paper roll, some wire, a used razor blade and a piece of pencil lead. I also needed an earphone and a variable capacitor. At a phone booth in the candy store, I stole the earpiece off the handset, and my mother took me to “Radio Row” on Canal Street, where I bought the capacitor for a nickel. I wired everything up, and I could hear music. No batteries, no electricity — just energy out of the air.
So you decided to become a scientist?
I didn’t want to commit to science immediately. My father wanted me to be an accountant. But the Bronx High School of Science was probably the best high school in America then, and I took their test and got in. One of my first classes was social studies. I was so glad it wasn’t science. But the teacher said, “We’re going to study social studies using the scientific method.” I thought, “Oh, God.” But the course was great, and I had a wonderful time there.
What came next?
I wanted to go away to college, but I couldn’t afford it. I finally decided on City College of New York [CCNY]. I was set to go during the day, but my father urged me to take a job at my cousin’s industrial electronics firm, since he needed me to help support the family. So I went to night school. And who teaches night school? Working engineers, who could give us a lot of practical knowledge, in addition to theory. Meanwhile, I was also learning on the job. It took me five and a half years to graduate with a bachelor’s in electrical engineering.
How did you get to graduate school?
A man from Lincoln Lab at MIT came to CCNY to talk about a fellowship program. I took off work early to hear him. The fellowship paid you well as a research assistant while you went to MIT, and it also helped with room and board. In the summers, you’d work at the MIT Lincoln Lab. At the end of the lecture, a CCNY professor from the daytime program handed out applications, and when I asked for one, he said, “I’ve never seen you in class.” I said I went to evening session. He said, “Get out of here!” So I wrote and asked for an application. I was the only one to get the scholarship.
How did computer science enter the picture?
As I was finishing my master’s, my thesis supervisor said I just had to get a Ph.D., which I hadn’t planned on. By then I had a wife and son to support. I agreed, with two conditions: one, I would work for the man I considered the best professor at MIT, Claude Shannon; and two, I would work on something that had significant impact. Shannon agreed to take me on and initially had me working on the strategy for a computer to play the game of chess. This was exciting, but I was not interested in working on that for my Ph.D.
What did you decide to research for your doctorate?
At MIT and Lincoln Lab, I was surrounded by computers. I knew that one day they would have to talk to each other, but there was no networking technology to enable that effectively. So for my Ph.D. research, I created a mathematical theory of packet networks. This involved a mathematical analysis of packet switching, in which messages are broken into a sequence of smaller, fixed-length pieces, later to be called packets.
What was the theory based on?
It was based on something very familiar to us today through businesses like Airbnb and Uber: the idea of sharing underutilized resources. In a data network, the communication lines are expensive. You can’t let them sit idly if there’s no data to send. If I’m sending something and I’m done, somebody else can use that line. I call it dynamic resource sharing.
How did this later impact UCLA?
I came here in 1963, and in 1969, because of my networking expertise, UCLA was chosen to be the first node on the ARPANET, a government-supported data network funded by the Advanced Research Projects Agency within the U.S. Department of Defense. The first Internet switch [Interface Message Processor, or IMP] was delivered to my lab on Labor Day weekend, and on the day after Labor Day we moved data between the UCLA computer and the IMP. But one node a network does not make. A month later, though, the second node was added at Stanford Research Institute [SRI]. So on October 29, 1969, we attempted to “login” to SRI through the network. We typed in “LOG,” but the system crashed after “LO.” SRI received the “LO,” though, and the first message had been sent. “LO,” as in “lo and behold,” was not a prepared message, but it could not have been more profound or prophetic. The Internet was born.
Fifty years later, how do you feel about what you started?
I’m worried that with the issues of rogue nation-states, of organized crime, of crazies coming in, that people are beginning to get protective and will put boundaries around their portions of the Internet. Up until the early 1990s, we could continue to experiment with the Internet, change it, make it solid, curate it. But when the profit motive came in around that time, the direction changed. The dark side emerged for hacking, privacy invasion, identity theft, fraud and all the rest. I fear that we might end up with a balkanized network where things will not be freely accessible. It defeats the openness of the original Internet culture, which was free, trusted, shared, open and ethical. Those were key concepts in the early days. It’s going to be a challenge to keep the Internet free and flexible.
What about the future?
There are two aspects. One is the underlying networking — the connectivity and the protocols. We can anticipate where that’s going. Thanks to the Internet of things, the Internet is disappearing into the infrastructure and finally will become invisible. It will be everywhere, and we will interact with it in a natural way. It will become a pervasive, global nervous system across the planet. That’s not hard to predict, but we have been woefully bad at predicting which applications and services will get popular on the Internet. Nobody predicted email, nor Napster, YouTube, search engines, social networks. Nobody saw them coming. Basically, we’ve created a system that will constantly surprise and shock us — and what a wonderfully exciting future it can be.