September 09, 2002

10 choices that were critical to the Net's success

By Dan Gillmor
Mercury News Technology Columnist

In our modern, corporate culture, the rise of the Internet is a happy accident. In its roots and growth, says Scott Bradner, the Net never had a business model.

How did technologists, government officials and a host of other early players turn something with no obvious business model into a system that has become so intrinsic to the new century? A series of decisions proved critical -- choices that helped turn data transport into a commodity business and put the power in users' hands, not in the centralized telecommunications companies' controlling grasp.

At a telecom conference in Massachusetts last week, Bradner, senior technical consultant at Harvard University and a longtime leader in the formation of Internet standards, listed 10 crucial decisions along the way. (You may have other candidates; send them to me and I'll list them on my Web page). Here are Bradner's picks:

1) Make it all work on top of existing networks. Designers deliberately didn't try to build a single, new über-data network -- it was about ``networks, not a network,'' Bradner observes. This meant supporting multiple network types by putting a simple set of rules, now called the Internet protocols, on top. This added layer was wide open for innovation, not controlled by a few players.

2) Use packets, not circuits. Telephone networks open a circuit from one phone to another, keeping the connection open until the call is ended. The Internet splits messages into little packages called packets, which are sent to their destination by various routes and at various times. This was a radical idea at the time, but it has been one of the qualities that makes the Internet so basically reliable and resilient under stress.

3) Create a ``routing'' function. Stand-alone boxes along the way from point to point make instant decisions on what route to send each packet by, reacting to failures in the networks. Again, this was a decentralizing function that enhanced reliability.

4) Split the Transmission Control Protocol (TCP) and Internet Protocol (IP), which are generally used together in much of what we do on the Net and are called TCP/IP. Originally they were meant to be tied together in a single service designed to guarantee that the stream of data would get to its destination complete and in perfect order. To do this, however, would have given network services far less flexibility. IP by itself offers an unreliable but still enormously valuable service, simply sending the packets through the network without checking to see if they all get there.

TCP makes sure, among other things, that they actually do get there. So an application can use TCP if it cares most about reliability, while another application can use IP (and other protocols) if it's more concerned with timeliness -- such as an Internet phone call -- where losing a few packets matters much less than getting most of the data there on time.

5) The National Science Foundation (NSF) funds the University of California-Berkeley, to put TCP/IP into the Unix operating system originally developed by AT&T. Berkeley thereby created a full but low-cost network operating system, along with a full suite of network applications, that computer start-up companies flocked to use in their boxes. It was, says Bradner, ``a way to get into the networking game without spending a lot of money.'' So it spread fast.

6) CSNET, an early network used by universities, connects with the ARPANET, the Internet precursor network operated by the Pentagon's Advanced Research Projects Agency. ARPA funded much of the early technical work on what later became the Net. ARPANET use had been restricted solely to government-funded individuals. The connection was for e-mail only, but it led to much more university research on networks and a more general understanding among students, faculty and staff of the value of internetworking. When students graduated, they sought employers that had the technology.

7) The NSF requires users of the NSFNET to use TCP/IP, not competing protocols. This decision about the NSFNET, which was originally created to connect supercomputer centers, forced wider availability of the TCP/IP protocol, and helped prevent a wasteful ``proliferation of miscellaneous transport protocols for the Internet,'' Bradner says.

8) International telecommunications standards bodies reject TCP/IP, then create a separate standard called OSI. TCP/IP, remember, was designed as a low layer on top of which other applications, such as e-mail, would be created. OSI was carrier-centric, a suite of protocols that included things like e-mail. Had TCP/IP been accepted and then co-opted by the international groups and telecom companies, things we now take for granted might not have appeared, or might have been under central control. One the fundamentals of the Net is we can create new protocols on top of IP, as Tim Berners-Lee did to create the World Wide Web, says Bradner -- ``and we don't have to have permission of the carriers to do that.

9) The NSF creates an ``Acceptable Use Policy'' restricting NSFNET use to noncommercial activities. Although this rule grew blurry, it was largely heeded despite fierce criticism. The result was an incentive to create commercial network providers. The commercial providers created a huge business of long-haul ``backbone'' and local carriers upon which the Internet relies today.

10) Once things start to build, government stays mostly out of the way. If the Internet suffered from a lack of regulation, Bradner says, it was ``a good suffering'' for all of us.