LEN KLEINROCK on the Origins of the Internet: "This is login"

Petrie: Are we talking TCP at this time?

Kleinrock: Oh, no. The original control protocol was NCP [Network Control Protocol].

Petrie: So at this point what were you doing for the equivalent of FTP and telnet?

Kleinrock: TCP doesn't play telnet. Telnet was there ahead of time, early on. There was ICP, which is the Initial Connection Protocol. There was the host to host protocol. There was even a voice protocol. There was a file transfer protocol. And there was telnet. All those things were being developed, and the idea of layering these protocols was already present in the early Arpanet days, way before IBM came out with theirs or the ISO/OSI seven-layer architecture. It was all in the early Arpanet design.

Petrie: And email quickly began to dominate the early use?

Kleinrock: Almost immediately. I'll tell you the first illegal use of the Internet. I did it. [laughter] In 1973 we had a meeting in the University of Sussex in Brighton, England, on computer communication networks. We were housed in dormitories on the campus. I had to leave a day early and when I got home, I noticed I'd left my electric razor in the dormitory. I wanted to get it back. The conference had set up a temporary link from London, which was on the Arpanet at the time, down to Sussex. And I said, "Gee, who would be logged on somewhere in the network. It was 3:00 in the morning Sussex time. What fool would be logged on at that time? I thought, "Ah! Probably Larry." There was a program called Resource Sharing Executive. It knew it lived in a network. So you could say "Where Roberts," and it would log onto every host, look at the "who" list, see who was logged on. The network was still small enough in those days that you could do that.

Petrie: That was the early equivalent of Finger?

Kleinrock: Exactly. A couple of minutes later it came back, "Roberts logged on as TT [teletype such-and-so] at BBN." I connected to him with a "talk" session. I said Larry, blah-blah-blah. He said, "Don't worry." Next day, I got my razor!

Petrie: [laughter] The first personal use.

Kleinrock: [laughter] As far as I know.

Petrie: In that particular example it sounded more like chat than email.

Kleinrock: It was chat. Not email. We had a split screen. Actually, it wasn't a split screen. It was line after line; it used "GA" for "go ahead," that kind of thing.

Petrie: But there you are. What year was this?

Kleinrock: It was 1973.

Petrie: So in 1973 you already have email, chat, telnet, everything.

Kleinrock: Yeah. It was all there. What happened then was that Larry initiated a satellite packet radio program in about 1972 or 1973. That's where Norm Abramson introduced the Aloha technology. Aloha had been in use to connect the various islands of the Hawaiian chain to the University of Hawaii, and we adopted it for satellite use. I did the analysis for that as well. And we got a satellite link across the Atlantic doing Aloha, broadcasting from four nodes. The interesting part here is that we were the Network Measurement Center in California, measuring and controlling a satellite over the Atlantic, using the Arpanet to get to it. It was a real kick. Before Larry left he began to start a program in packet radio, ground radio, which Bob Kahn then took over.

Petrie: This is the idea of what some people have called the data sphere.

Kleinrock: Yes. No base stations, just plop down the radios. The military environment is what we were using as a model application.

Petrie: You would parachute in a whole bunch of radios?

Kleinrock: With people or whatever, and they form a network. The key idea was that there were no "base stations." Rather, multi-hop technology was used to cover distances. This was a very hard problem to solve. The first thing you have to choose is the channel access method. Once again, Abramson's group from Hawaii had been trying something called CSMA, carrier sense multiple access.

Let me back up. At one of the first meetings Abramson came to, he talked about Aloha. I was there with one of my PhD students, Simon Lam. We looked at ourselves and said we just have to analyze the behavior of Aloha. So I put him on to it and we solved Aloha. A couple of years later, I was at another meeting for packet radio with another of my PhD students, Fouad Tobagi. Abramson comes again, this time with CSMA, and writes an equation on the blackboard describing the throughput-traffic relationship. I looked at it and said, "That's wrong."

On the airplane ride home, we analyzed it and got the correct and exact answer. In fact, we analyzed a more general version of the problem. That was the first analysis of CSMA, which then led to CSMA/CD which is the Ethernet protocol.

Petrie: Really?

Kleinrock: Bob Metcalfe took the CSMA protocol we had analyzed, which means you listen before you talk, and he added CD [collision detect] — which means you listen while you're talking — and put it on a wire. By the way, Ethernet is the wrong name. It's not over the ether; it's over a wire. But at least it had CSMA/CD.

The latest version of Ethernet no longer has CSMA/CD. Gigabit Ethernet has abandoned CSMA/CD for some of its modes. So what does it have? It's not Ethernet anymore. It has a frame format that's common, that's all. Anyway, the point I'm making is we had the Arpanet, we had the satellite network, now we had the packet radio network. Three networks. They couldn't talk to each other very well. And that's what motivated Bob Kahn to conceive the idea of TCP/IP. He later described the ideas to Vint Cerf, and suggested to Vint that he install it at the operating system level. It was Bob's idea to put it together.

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