GUY RAZ, host:
We're back with ALL THINGS CONSIDERED from NPR News. I'm Guy Raz.
It's been 40 years since the invention of what we now know as the Internet. And over the last few weeks, we've been exploring the people and ideas behind the network. It's our series The Net at 40.
Now, when you type a Web address, say, my personal favorite npr.org, you should thank a man named Paul Mockapetris for making it all so easy. Dr. Mockapetris developed a system that associates a string of numbers with a name. For instance, the IP address of npr.org is this: 126.96.36.199. You can type either one into your Internet browser and get NPR's Web site, but it's much easier to remember npr.org.
It's called DNS � the domain name system � and Dr. Mockapetris joins me from Paris. Welcome to the program.
Dr. PAUL MOCKAPETRIS (Developer, Domain Name System): Thanks for having me.
RAZ: Dr. Mockapetris, how did you come up with this idea? I mean, were you asked to do it?
Dr. MOCKAPETRIS: I was actually given the job of taking five different proposals and harmonizing them together. And nobody noticed that I did something completely different.
RAZ: When was this?
Dr. MOCKAPETRIS: The system was first used in 1983 and I think was in production use in about 1986 or so. In the early days, we have a lot of freedom to experiment with it. So, the system was recognizable as we know it in '83.
RAZ: And before that, you had worked on something called the ARPANET, which we've talked about on this program, this sort of computer-to-computer network -the first computer-to-computer network that was created at the Pentagon in the late '60s.
Dr. MOCKAPETRIS: You know, I tend to think of that as sort of the dinosaur age. And 1983 was the year that we had a big change-over to IP, TCP, and DNS and all of these new protocols. It was sort of the start of mammals on the Internet. It was a very heady time because people basically took the experience they had of the ARPANET and just completely redid everything with a clean sheet of paper.
RAZ: So, until that point, if you wanted to communicate with another computer, you had to be part of the same network. It was almost as if, if you spoke English, you could only speak to other English speakers. The Internet enabled people who spoke several different languages to communicate.
Dr. MOCKAPETRIS: Or another way to think about it is is that it might be the difference between different airlines and buses and boats and so forth. With the Internet, you can get up, take the first part of your communication over a wireless network, like the bus, and then you can go to an airport and get on a long-haul network and then get off and take a train at the other end. The whole idea is is it made all of these different ways of transporting data work just as we would expect you to be able to take a trip on a conventional transport system.
RAZ: And because of those changes, you had to come up with this domain name system, right?
Dr. MOCKAPETRIS: Well, everybody that wants to play on the networker, whether it's to have an email address or to connect to computer, needs a name for that. And I foresaw at the time that there might be 50 million of those one day. And so we designed to meet that goal, or at least that's the goal that I had in mind when I did it.
Now, today, things have grown to probably several billion different names. 'Cause, remember, it's not just machines; it's also individual email addresses or any of the identifiers.
RAZ: So, will we reach a point when it's saturated, when the system that you created can no longer handle the amount of names?
Dr. MOCKAPETRIS: Well, if you think of it as sort of geography, there's only so much beachfront land that you can find but there is an awful lot of addresses still. And the same thing is true with domain names. Some people argue that the ones that they really want are already taken. But if you're willing to settle for a second or third choice, there's probably more domain names than there are people on Earth, phone numbers, automobiles and pets put together.
RAZ: Do you remember the first domain name that you made?
Dr. MOCKAPETRIS: Well, I was doing the work at ISI, so I'm sure it was isi.edu. That was part of the University of Southern California.
RAZ: And was there a number attached to that?
Dr. MOCKAPETRIS: 10-00-52, I believe.
(Soundbite of laughter)
RAZ: So, do you get a cut every time someone registers a domain name?
Dr. MOCKAPETRIS: A friend of mine said I was smart enough to invent the DNS, but not smart enough to own it.
(Soundbite of laughter)
RAZ: That's Dr. Paul Mockapetris. He is the inventor of the Domain Name System, or DNS. He joined us from Paris. You can listen to and read more from our series, The Net at 40, by typing in our domain name. That's npr.org.
Dr. Mockapetris, thanks for joining us.
Dr. MOCKAPETRIS: Happy to do so.