The OSI Deprogrammer
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The OSI Deprogrammer
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Re: The OSI Deprogrammer
#2This is hilarious. I happen to be preparing for a test centered around the OSI model and I don’t get why it’s set this way. Every few paragraphs the text says something like “remember that nowadays things a bit fuzzier and don’t fit within one layer” well then why are we even using this model?
Re: The OSI Deprogrammer
#3Reminds me of how modern Linux systems still behave as though they're printing to a teletype.
Re: The OSI Deprogrammer
#4This is wonderful material. But admittedly, I am a bit lazy on reading to the part I want: what is a good model, or set of models, I should re-educate myself with to correct what I was taught?
Re: The OSI Deprogrammer
#5I mean, this isn't bad or anything, and if Rob Graham is going to write about anything with authority, this is certainly it, but it's kind of beating up a straw man, isn't it? I feel like "layering violations" went out the window with HTTP, and certainly by the time we got WebSockets.
Re: The OSI Deprogrammer
#6This is wonderful material. But admittedly, I am a bit lazy on reading to the part I want: what is a good model, or set of models, I should re-educate myself with to correct what I was taught?
Ethernet, IPv4, TCP, and HTTP; what functions do each provide, how is each coupled to its neighbor, and what are the viable alternatives in the design spaces of each?
Part of the OSI layering model was I think meant to get people's brains wrapped around the dynamics of packet switching networks, which were once a novelty and are now just part of the air we breathe.
Then, read:
https://web.mit.edu/Saltzer/www/publications/endtoend/endtoe...
Re: The OSI Deprogrammer
#7This is funny
Under: 7.1.2. Poorly understood terminology >This is what happened with “session”. When OSI named this layer, it had nothing to do with sessions in general, but with very specific issues connecting a terminal to a mainframe. [...] What we think of as sessions (as in HTTP) are actually called associations in OSI, and is assigned to the Application Layer #7.
Re: The OSI Deprogrammer
#8I mean, this isn't bad or anything, and if Rob Graham is going to write about anything with authority, this is certainly it, but it's kind of beating up a straw man, isn't it? I feel like "layering violations" went out the window with HTTP, and certainly by the time we got WebSockets.
It's not great. It reads like some angsty nerd who really doesn't like the idea of something and has spent an inordinate amount of time trying to explain why it's wrong and why his solution is better. Sometimes that works, if your name is Locke or Marx or something, but this writing really doesn't say "genius" to me.
Moreover, I have not heard anyone but myself utter the word "OSI" out loud in 8 or 10 years. Maybe it's still a thing in academia, but it's not in corporate or open source worlds. I don't know if I've met more than 2 people in 5 years that know how TCP works. It's just a magic tunnel that HTTP somehow uses under the covers. So I really don't get the need or purpose for this document. It's like describing in excruciating detail that what you know about the ancient Egyptians is a lie, because that's somehow going to be necessary for somebody?
Re: The OSI Deprogrammer
#9This is hilarious. I happen to be preparing for a test centered around the OSI model and I don’t get why it’s set this way. Every few paragraphs the text says something like “remember that nowadays things a bit fuzzier and don’t fit within one layer” well then why are we even using this model?
As models go it’s pretty good, and no one has made a better one. Seriously. The layers are all useful concepts to know about and discuss, even if in some cases it is most practical to blur the lines or outright combine two of them into one protocol. You will at least know that you are doing so, and you will know to point out _why_ you are. But nobody has ever determined that it is _always_ best to combine two of the layers (which would really amount to proving that the two are in fact the same thing). But since nobody can prove that it is _never_ a good idea either, it remains a model and not a theorem with a proof.
Edit: but I will also say that any test or certification which focuses too much on the OSI model is also suspect. I don’t know what test you’re about to take, but plenty of people will sell you certifications that in the end are meaningless.
Re: The OSI Deprogrammer
#10This is hilarious. I happen to be preparing for a test centered around the OSI model and I don’t get why it’s set this way. Every few paragraphs the text says something like “remember that nowadays things a bit fuzzier and don’t fit within one layer” well then why are we even using this model?
Because all models are wrong, but some models are useful.
OSI is a useful model, especially at lower layers, because it covers the abstractions from physical to network to internet to protocols, and that is a useful way to think about things.