Complete breakdown every little detail of OSI Model?

DisarrayDisarray Posts: 4Member ■□□□□□□□□□
Hi I'm studying the OSI Model right now and while I definitely think I have the basics of it covered I really want to know all the gory details and I'm finding that extremely difficult to do since I've yet to find an article/guide/tutorial/etc that details every little thing that happens through it.

So first and foremost does anyone have a complete guide to the OSI model?

I should state my goal is to be able to in my head go through every single little thing data does as it goes through the OSI Model.

What I mean by complete is a guide that shows the data traveling through the model and taking you through every single little thing that happens.

Let me give you an example of the type of details I'm talking about that everything I've seen dealing with the OSI Model leaves out.

Regarding the three-way handshake that takes place at the transport layer my Sybex CCNA book

Basically describes it like this...

1)The first segment is for a synch request

2)The second and third segs acknowledge the request and establish the connection rules.These segs request the reciever sequence is sycned here as well so that bidirection connection is formed.

3)Final segment also and acknowledgment, notifies destination host the connection agreement is accepted and connection has been established

Now while perhaps (?) thats all I may need to know for the CCNA exam it leaves out a ton of information

I found an example though of what I would have liked to know on google and you can view that here

Some key things I gathered from that link that I didn't get from the book are

For one the just reading the book I think you could see how one could develope a garbled picture of the sequence number and the synchronize bit set

It would be even harder to differentiate between the ACK: number and the Acknowledgement field

Nor would you be able to figure out that each system has it's own independent sequence numbers
(when I read the book I imagined the sender would go 1 receiver 2 sender 3 and back and forth, but thats obviously not what happens at all

And I could go on......and on...........

And even regarding far more general things in the OSI model their are numerous details left out of every guide on it I've seen thus far.

I have to imagine I'm not the first one to realize this and have tried to piece together the whole thing so if anyone knows of any very detailed guides that be great.

I should mention since I'm sure the first thing someones going to do is point me to this boards technotes is that those notes regarding the OSI, though while a good brief overview are a far, far cry from the level of detail I'm looking for.


  • dynamikdynamik Posts: 12,314Banned
    You're going to want to research the RFCs for whatever protocol you're interested in.

    i.e. Here's the one for TCP:

    Just google "<protocol> rfc" i.e. arp rfc, dhcp rfc, etc.
  • DisarrayDisarray Posts: 4Member ■□□□□□□□□□
    Well ya your right, I'm obviously going to have to go more into each relevant protocol in my study.

    So perhaps my example was a bad one as I'm talking about detail on the OSI model in general then I am protocols.

    I mean theirs a lot to the OSI model yet every guide on it I've run into is no longer then 2 pages when from what I've seen thus far you could probably spend at least a couple pages on each Layer describing what it does, how it interfaces etc. without anything more then generically and briefly talking about protocol specifics.

    Or am I wrong? Am I going about this the wrong way..?

    I mean the way every book/guide dealing with the CCNA material I've seen always just generally goes over the OSI model and then jump into completely different things.

    While I personally feel the need to have a complete understanding of the model before I move on at all... Should I just go with the books or learn the layers detail by detail along with all the relevant protocols...?
  • networker050184networker050184 Posts: 11,962Mod Mod
    The OSI model is just that, a model. Not every protocol interacts with every layer of the OSI model. I think you are WAY over analyzing it.
    An expert is a man who has made all the mistakes which can be made.
  • dynamikdynamik Posts: 12,314Banned
    There really isn't that much to it. It's just a model to help you understand how equipment and protocols interact with each other. Maybe use this for a review:

    edit: too slow. +1 Networker
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