Petrie: This was two years after you published your dissertation?
Kleinrock: That's when the book came out. The dissertation was officially published when I handed it in, in 1962. Larry saw my early drafts, the whole thing. He was totally influenced in his thinking by my work on networking. That's why he accepted the job — he knew that the technology was doable.
So Larry called me in, and in 1967 he gathered half a dozen people together to try to write the specification for what this network would be. Fred Baskins was there. He was a time-sharing buff, and he banged his fist on the table and said, "If this network can't give me a half a second response time, I can't do time sharing." So we said okay, the spec is a half a second roundtrip.
Then I banged my fist on the table and said, "Look, this is an experiment. We have to know what's going on, we have to put measurement hooks in the network switches." These measurement hooks in the software should contain artificial traffic generators, measure traffic flows, collect and display histograms and other measurement tools. There was also the issue of reliability. How do you specify reliability? Well you could do it the way the military does and ask that the network be operational 0.9999721 percent of the time ... which is nonsense. We chose a far more pragmatic measure. We said that if any single link breaks, the network should still function. That meant that there would have to be two independent layers. So we wrote the spec. In January 1968, we released the spec. It was a request for a proposal. In January 1969, BBN [Bolt, Beranek, and Newman] won the bid. Their job was to select a minicomputer, modify the hardware and software to meet the spec that we had created for the switching node, what we called an IMP [interface message processor]. They also had to manage the Arpanet — you know, worry about the lines staying up, talk to AT&T, talk to all the modem manufacturers, lease 50 kilobit-per-second lines, and more.
Because I had done the pioneering work on networking, it was decided that my UCLA lab would become the first node on the network, and we would become the network measurement center as well. It was our job to stress the network, run experiments, try to test it and crash it if we could.
Petrie: So UCLA was the first node. Did you have the IMP yet?
Kleinrock: No, not yet. We had to get ready for this IMP that BBN was putting together. And their switch was coming in September 1969, and we needed to get the IMP to host the specification that BBN was supposed to deliver.
Petrie: What was the host machine?
Kleinrock: A Scientific Data Systems, Sigma 7-SDS Sigma 7.
Petrie: And the IMP was a DEC?
Kleinrock: No, it was a Honeywell minicomputer. Honeywell announced this machine in 1968, and they showed it, I believe, at the Fall Joint Computer Conference, 1968, in one of the big cities. They had a military hardened version with four eyehooks on top. At the show, they had it suspended from the ceiling, lights running, swinging in the air, and a big strapping guy with a sledgehammer was whacking the side of the machine to show it wouldn't fail. And it didn't fail; it kept working. And by the way, I think that's the machine we got. There were no dents in ours, but we have a hardened version at UCLA.
Petrie: It's still there?
Kleinrock: Yep, it's still there. And the heck of it is, that neither the UCLA Chancellor, nor the LA make any publicity about it. You know, Philadelphia is the City of Brotherly Love, right? Los Angeles is the city where the Birth of the Internet took place. You'd think a politician would take that and run with it!
Petrie: This wasn't a very big machine?
Kleinrock: No — the size of a public telephone booth or a refrigerator. It had 16K of RAM and 16 levels of interrupt. It could handle eight lines including host interfaces and lines out into the network. That was the max.
Petrie: So now you've got a team of guys working to write the interface?
Kleinrock: I put together a software team and a hardware team, a total of 40 people. We had to build the interface and write the protocol according to spec that BBN finally released to us. The hardware team was headed up by Mike Wingfield. The software team was headed by Steve Crocker. And underneath him were Charley Kline, Vint Cerf, Jon Postel, and others. They were a fine team of people and they were writing the code for the IMP.
Petrie: And what were they writing in?
Kleinrock: It was assembly language I think. I can't recall. I didn't do any of the programming, didn't want to.
Petrie: And Crocker was the head of the team?
Kleinrock: He was the head of the software team. They were aggressive guys, as software guys tend to be. Shortly after the IMP was installed we had the problem of creating the host/host protocol. We had developed the IMP/host protocol, and now we needed host/host. That was a major, major effort. We didn't realize how hard it was. I gave it to this distributed group of graduate students around the community, and it took them two years to write it, but it finally got written. During that period the network was not very well used because there was no easy way for hosts to talk to each other. About the only way that happened is if somebody, say from Utah, took a job at Santa Barbara and wanted to talk to his machine back in Utah, he knew just how to do it. So it was migration of people that allowed the early work to get done. And finally the protocols were put in place.
I want to backtrack on one thing about Larry [Roberts]. Larry certainly had strong credentials in networking. He conducted the first experiment trying to connect two computers together. He connected the machine at Lincoln Lab to a machine at SDC (Systems Development Corporation) in Santa Monica. And it was terribly hard. This I believe was in 1966. It was a failure, basically. I mean it was gruesomely hard because there was no protocol, no understanding of what to do. That's another reason why he was prepared to try to create this network.