'The Web was invented by the British but exported to the US... We don't want that to happen again.'

Les Schaffer godzilla at netmeg.net
Mon May 22 16:54:08 PDT 2000


Mark Jones said:


> If there's a limit on postings here i'm no doubt over it, sorry, but
> in fact what I was thinking of was that the WWW protocols were
> designed by an Englishman, whose name I've forgotten anyway

Tim Berners-Lee?

some more history; here's from my "Computer Networks, 3-rd Edition", Tannenbaum"

==================

The ARPANET

... In the mid-1960's, at the height of the Cold War, the DoD wanted a command and control network that could survive a nuclear war. Traditional circuit-switched telephone networks were considered too vulnerable, since the loss of one line or switch would certainly terminate all conversations using them and might even partition the network. To solve this problem, DoD turned to its research arm, ARPA (later DARPA, now ARPA again), ...

ARPA was created in response to the Soviet Union's launching Sputnik in 1967 and had the mission of advancing technology that might be useful to the military. ARPA had no scientists or laboratories, in fact, it had nothing more than an office and a small (by Pentagon standards) budget. It did its work by issuing grants and contracts to universities and companies whose ideas looked promising to it.

Several early grants went to universities for investigating the then-radical idea of packet switching [c.f. Nathan's comment on National Post Office], something that had been suggested by Paul Baran in a series of RAND Corporation reports published in the early 1960's. After some discussions with various experts, ARPA decided that the network the DoD needed should be a packet-switched network, consisting of a subnet and host computers.

[snip]

To deal with problems of host software, Larry Roberts of ARPA convened a meeting of network researchers, mostly graduate students, at Snowbird Utah, in the summer of 1969. The graduate students expected some network expert to explain the design of the network and its software to them and and then to assign each of them the job of writing part of it. They were astounded when there was no network expert and no grand design. They had to figure out what to do on their own.

Nevertheless, somehow an experimental network went on the air in December 1969 with four nodes at UCLA, UCSB, SRI, and Univ. of Utah. These four were chosen because all had a large number of ARPA contracts, and all had different and completely incompatible host computers (just to make it more fun).

[snip]

This experiment [was snipped] also demonstrated that the existing ARPANET protocols were not suitable for running over multiple networks. This observation led to more research on protocols, culminating with the invention of the TCP/IP model and protocols (Cerf and Kahn, 1974). TCP/IP was specifically designed to handle communications over internetworks, something becoming increasingly important as more and more networks were being hooked up to the ARPANET.

To encourage adoption of these new protocols, ARPA awarded several contracts to BBN [Bolt Benarek and Newman] and the Univ. of California at Berkeley to integrate them into Berkeley UNIX. Researchers at Berkeley developed a convenient program interface to the network (sockets) and wrote many applications, utility, and management programs to make networking easier [and to allow lbo to function].

The timing was perfect. Many universities had just acquired a second or third VAX computer and LAN to connect them, but they had no networking software. When 4.2BSD came along, with TCP/IP, sockets, and many network utilities, the complete package was adopted immediately. Furthermore, with TCP/IP it was easy for the LANs to connect to the ARPANET, and many did.

[earlier, on battle between OSI and TCP/IP and why OSI lost]

It now appears that the standard OSI protocols got crushed. The competing TCP/IP protocols were already in widespread use by research universities by the time the OSI protocols appeared. While the billion-dollar wave of investments had not yet hit, the academic market was large enough that many vendors had begun cautiously offering TCP/IP products. When OSI came around, they did not want to support a second protocol stack until they were forced to, so there were no initial offerings. With every company waiting for every other company to go first, no company went first and OSI never happened.

Bad Technology

The second reason that OSI never caught on is that both the model and the protocols were flawed. Most discussions of the seven-layer model [OSI] give the impression that the number and contents of the layers eventually chosen were the only way, or at least the obvious way. This is far from true. The session layer [in OSI but not TCP/IP] has little use in most applications and the presentation layer is nearly empty. In fact, the British proposal to ISO only had five layers, not seven. In contrast to the session and presentation layers, the data link and network layers are so full that subsequent work had split them into multiple sublayers, each with different functions.

Although hardly anyone ever admits it in public, the real reason that the OSI model had seven layers is that at the time it was designed, IBM had a proprietary seven-payer protocol called SNA (Systems Network Architecture). At that time, IBM so dominated the computer industry that everyone else including telephone companies, competing computer companies, and even major governments, were scared to death that IBM would use its market clout to effectively force everybody to use SNA, which it could change whenever it wished. The idea behind OSI was to produce an IBM-like reference model and protocol stack that would become the world standard, and controlled not by one company, but by a neutral organization, ISO.

The OSI model, along with the associated service definitions and protocols, is extraordinarily complex. When piled up, the printed standards occupy a significant fraction of a meter of paper. They are also difficult to implement and inefficient in operation,. In this context, a riddle posed by Paul Mockapetris and cited in (Rose, 1993) comes to mind:

Q: What do you get when you cross a mobster with an international standard?

A: Someone who makes you an offer you can't understand.

[snip]

In contrast, one of the first implementations of TCP/IP was part of Berkeley UNIX and was quite good (not to mention, free). People began using it quickly, which led to a large user community, which led to improvements, which led to an even larger community. Here the spiral was upward instead of downward.

Bad Politics

On account of the initial implementation, many people, especially in academia, thought of TCP/IP as part of UNIX, and UNIX in the 1980's in academia was not unlike parenthood (then incorrectly called motherhood) and apple pie [Tannenbaum is from Amsterdam]. OSI, on the other hand, was thought to be the creature of the European telecommunications ministries, the European Community, and later the US Government. This belief was only partly true, but the very idea of a bunch of government bureaucrats trying to shove a technically inferior standard down the throats of the poor researchers and programmers down in the trenches actually developing computer networks did not help much. Some people viewed this development in the same light as ISM announcing in the 1960's that PL/I wa the language of the future, or DoD correcting thus later by announcing that it was actually Ada.

les schaffer



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