OSI: The Internet That Wasn’t
spectrum.ieee.org
OSI: The Internet That Wasn’t
1–10 of 64 posts
Re: OSI: The Internet That Wasn’t
#2…but we're going to keep asking questions about the 7 layer model in interviews as if it were useful in the real world because that's what we learned about in school.
Re: OSI: The Internet That Wasn’t
#3As usual, /usr/games/fortune provides some insightful commentary:
"On the other hand, the TCP camp also has a phrase for OSI people. There are lots of phrases. My favorite is `nitwit' -- and the rationale is the Internet philosophy has always been you have extremely bright, non-partisan researchers look at a topic, do world-class research, do several competing implementations, have a bake-off, determine what works best, write it down and make that the standard.
The OSI view is entirely opposite. You take written contributions from a much larger community, you put the contributions in a room of committee people with, quite honestly, vast political differences and all with their own political axes to grind, and four years later you get something out, usually without it ever having been implemented once.
So the Internet perspective is implement it, make it work well, then write it down, whereas the OSI perspective is to agree on it, write it down, circulate it a lot and now we'll see if anyone can implement it after it's an international standard and every vendor in the world is committed to it. One of those processes is backwards, and I don't think it takes a Lucasian professor of physics at Oxford to figure out which."
-- Marshall Rose, "The Pied Piper of OSI"
Re: OSI: The Internet That Wasn’t
#4Interesting and we can see the outcome of the palace revolt is IPv6 OSI /telecoms guys would have insisted on having a workable inter-operation plan.
EX X.400 hacker here I used to have root on the UK ADMD back in the day :-)
Re: OSI: The Internet That Wasn’t
#5…but we're going to keep asking questions about the 7 layer model in interviews as if it were useful in the real world because that's what we learned about in school.
"I hear they're going to 42 layers because it's a sacred number in Bali."
Not from this guy. I might ask you to critique the 7 layer model, or provide me with ideas for speeding things up by skipping layers.
It's all mushed together in real stacks anyway, with dogs down in the cat layer, and mice doing double duty both at the metal and up there in the UI. I swear to god, OSI would have been standardizing finger lengths for keyboard interaction if someone had let them.
Re: OSI: The Internet That Wasn’t
#6…but we're going to keep asking questions about the 7 layer model in interviews as if it were useful in the real world because that's what we learned about in school.
"I hear they're going to 42 layers because it's a sacred number in Bali." Not from this guy. I might ask you to critique the 7 layer model, or provide me with ideas for speeding things up by skipping layers. It's all mushed together in real stacks anyway, with dogs down in the cat layer, and mice doing double duty both at the metal and up there in the UI. I swear to god, OSI would have been standardizing finger lengt…
I counter with the 9-layer model and that causes them to ask a more relevant question. This happens a lot when you're receiving a generic interview from a US Megacorp that has only recently ditched irrelevant (save for "how does this person think") quizzes for cross-functional interviews from people whose function is far removed from what you thought you were going to be interviewing for. (They all seem to have migrated to this strategy, for what that's worth.)
Re: OSI: The Internet That Wasn’t
#7Not too impressed with this account, which I will admit starting to skim around halfway. E.g.:
I'm not sure the author realizes TCP is a virtual circuit protocol (then again I'm sure OSI had one or more much heavier weight ones).
The real fatal flaw of OSI, before even getting to the point of finding out if their protocols worked---many of them did get far enough in standardization process---was their going to ISO in the first place. If you just needed to get things done, the difference between spending around $2,000 ($1,000 in 1988 dollars) to buy a shelf of the standards documents, or $0 or thereabouts to get all the RFCs (chicken and egg, you might need to buy a CD or a tape to get them to your systems), made a very big difference.
If you're really interested in all this, I highly recommend Padlipsky's very opinionated "The Elements of Networking Style: And Other Essays & Animadversions on the Art of Intercomputer Networking" (http://www.amazon.com/Elements-Networking-Style-Animadversio...), a very colorful work with rhetorical gems like "gilding the ragweed".
Re: OSI: The Internet That Wasn’t
#8Not too impressed with this account, which I will admit starting to skim around halfway. E.g.: I'm not sure the author realizes TCP is a virtual circuit protocol (then again I'm sure OSI had one or more much heavier weight ones). The real fatal flaw of OSI, before even getting to the point of finding out if their protocols worked---many of them did get far enough in standardization process---was their going to ISO in…
"not sure the author realizes TCP is a virtual circuit protocol"
That struck me too -- kind of undermining the simple narrative of "connection-full telecom biggies vs. connection-less insurgents". It would have been worth a note in the article, because it's in IEEE Spectrum after all.
Not a networking pro, but I believe the converse is also true, that OSI has specifically connection-less protocol elements (e.g., CLNS) that are at a lower level in its own hierarchy, and more equivalent to IP in TCP/IP.
I just saw part of an interview with Cerf (http://www.internet-history.info/media-library/mediaitem/100...), in which he said that part of the motivation for packet switching is to maintain command and control in the chaos of a post-nuclear-strike world. That explains why the person connected with packet switching (Paul Baran) was at RAND, which was not a networking place, but very much a "let's plan for the apocalypse" place.
Re: OSI: The Internet That Wasn’t
#9I can never see the term OSI an not think of this classic. It gave me and friends a good laugh back in the day ;p
(original site down but this is a mirror)
Re: OSI: The Internet That Wasn’t
#10Not too impressed with this account, which I will admit starting to skim around halfway. E.g.: I'm not sure the author realizes TCP is a virtual circuit protocol (then again I'm sure OSI had one or more much heavier weight ones). The real fatal flaw of OSI, before even getting to the point of finding out if their protocols worked---many of them did get far enough in standardization process---was their going to ISO in…
"not sure the author realizes TCP is a virtual circuit protocol" That struck me too -- kind of undermining the simple narrative of "connection-full telecom biggies vs. connection-less insurgents". It would have been worth a note in the article, because it's in IEEE Spectrum after all. Not a networking pro, but I believe the converse is also true, that OSI has specifically connection-less protocol elements (e.g., CLNS…
Well, there was a big controversy over basing your protocols on datagrams with stateless nodes in the middle. The CCITT's X.25 didn't.
When I was working for Lisp Machines Inc. (LMI) in 1982-3, when TCP/IP was being mandated for the Arpanet (and therefore Lisp Machines, sometime I worked on at LMI), I can remember the father of the Lisp Machine, Richard Greenblatt, arguing that it wouldn't work because too many packets would get lost in the middle. With stateless nodes---a necessary virtue for the small memory minicomputers the Arpanet was built on---re-transmission has to come from the endpoints, and if the error rate was too high it would have failed to be practical. Look at TCP over ATM for a modern example of this sort of lossage.
I assume Vint Cerf et. al. did the math based on observed error rates, then tested it to make sure (TCP/IP and NCP ran side by side for some time on the Arpanet) and Greenblatt, who was rather distracted designing his 3rd generation Lisp Machine, was going by general principles.