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Donald Mitchell
Research Scientist, Author. (Caltech, Bell Labs, Princeton University, Microsoft Research)
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Donald Mitchell 22 h
Odgovor korisniku/ci @SteveBellovin @marabou
I'd love to write something about the ACS project at Holmdel. Does anyone remember the long memo that Berkeley Tague wrote? It was hilarious. I think ACS/Net-1000 was like a billion dollar project that completely tanked.
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Donald Mitchell 23 h
Odgovor korisniku/ci @marabou
Historians and journalists often miss out on the good gossip. And I didn't even get started on Net-1000, a failed computer network project that bought 30% of all the computers built by Digital Equipment Corporation.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @oclsc
Yes, 1127 was an amazing research lab. The other two computer-research labs (1135, 1138) always had a bit of an inferiority complex.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @oclsc
It's hard to know how long something should be planned. OSI is a good example of way too much planning. And countless systems, formats, programming languages, are examples of quick careless planning.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @oclsc
Well they might have been right, even though they were wrong. I can't say that TCP/IP or HTML were really great solutions...but they were the solutions that won.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @DonaldM38768041
I saw a presentation of this system that included making fun of TCP/IP and laughing at the idea that AT&T would support the internet. Ironically, the internet still runs on top of that photonic network infrastructure.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @DonaldM38768041
AT&T's physical network was impressive technology: an all-photonic network with lithium-niobate crossbar switches, laser amplified undersea cables, and lossless token ring networks that serviced cities.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @DonaldM38768041
The lab I was in (1138) was something of a pariah, because we used ethernet and ran TCP/IP and Berkeley UNIX on our computers. We also got scolded by the communications-workers union, because we installed the ethernet cable ourselves.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @DonaldM38768041
Even while I was there in the 1980s, there was hostility and derision of the idea of packet switched networking. The 1127 research lab (where UNIX was created) built their own circuit-switched computer network they called Datakit.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @DonaldM38768041
And while we are talking about fumbling the future, I should also say something about AT&T, where I worked. The Army once asked them to take over and manage the ARPANET, and the company declined.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @DonaldM38768041
Fortunately, all of this happened well before 1995 when the internet became a mass media used by regular citizens. So I don't think the theory and experience learned from OSI were a disastrous waste.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @DonaldM38768041
OSI was an expensive failure; not only in terms of the cost of the specification and development, but in terms of the opportunity cost of delaying the deployment of the internet in Europe and Japan. Trust in standards committee was sullied by the project.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @DonaldM38768041
In OSI, the analogue to TCP was called TP4. Early implementations of that complex protocol were so slow, it took longer to send one packet than the timeout interval that TPC used to give up and close a connection.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @DonaldM38768041
In the internet, IP is the protocol for sending data packets, but without guarantee of delivery. The TCP protocol established a reliable data stream using IP...it put packets in order, tossed out duplicates and asked for re-transmission of missing packets.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @DonaldM38768041
ASN.1 had optional formatting schemes...for examples you could implement strings as null-terminated and/or length/data format. X.400 servers built in Germany and France were unable to exchange messages, because they each close a different string format.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @DonaldM38768041
I heard a lot of stories about OSI...mostly tales of disaster. A visiting researcher from IBM told us they built an X.400 email server, and they were appalled that, on a powerful mainframe computer, it took 1 full second of processing to send a single message.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @DonaldM38768041
I was at Bell Labs while OSI was happening, and I implemented some parts of the ASN.1 data-marshaling standard. This was sort of a binary version of XTML, an complicated way to define streams of data including text, integers, floating point numbers, and labels.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @DonaldM38768041
This was OSI, and it had at least one elegant theoretical idea, which was the protocol stack -- a logical layers of how you go from copper wires to network applications.
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Donald Mitchell 2. velj
Odgovor korisniku/ci @DonaldM38768041
The Internet was starting to spread rapidly in the 1980s. Finland was buying CISCO routers like crazy. In the USA, TCP/IP was taking over as the preferred network protocol. But in Europe and Japan, there was a decision to define their own data network standard.
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Donald Mitchell 2. velj
Came across some of my old CCITT/OSI books. I think the theory of the OSI stack is still taught in the classroom, but I suspect a lot of the lore will be forgotten.
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