OSI model help

Admiral Akmir

The OSI model is a topic that never seems to stick for me. It just feels really obscure, I have a hard time connecting it to real world stuff. How did you guys study it, any advice?

Hatch1921

Have a look here if you haven't... might be helpful?

CCNA TechNotes: OSI model

PCHoldmann

I was just finishing up a layers post, although it will probably be best after studying something like the technote above.

Practical OSI Layers – Part 1 | Route, Switch, Blog

martell1000

Admiral Akmir wrote: »

The OSI model is a topic that never seems to stick for me. It just feels really obscure, I have a hard time connecting it to real world stuff. How did you guys study it, any advice?

welcome to the club - took me forever to understand this thing.

first thing you need to remember is: Please Do Not Throw Sausage Pizza Away

P D N T S P A

and then watch this

The OSI Model Demystified - YouTube

if you have any questions left after that feel free to ask

Cleverclogs

I was going to suggest the Sausage Pizza acronym, but Martell1000 beat me to it. Thanks also for the video, some good stuff on Eli's channel

Elijah09

I find the " All People Seem To Need Data Processing" works better for me.
And it's easier to remember ...

Application
presentation
Session
Transport
Network
Data ink
Physical

Admiral Akmir

Thanks for the replies guys.

One thing that confuses me is that the 3 way handshake takes place at the transport layer, but the session layer is said to set up and tear down communication between devices. Isn't the 3 way handshake setting up communication? It makes sense that it would be at the session layer rather than the transport.

PCHoldmann

One of the problems with the OSI model is that TCP/IP is the most common protocol stack in use today, but it is older than the OSI model, so some things don't match up perfectly between the two. So it might make more sense to be at the session layer, but in TCP/IP it ends up in Layer 4 as part of TCP.

Admiral Akmir

PCHoldmann wrote: »

One of the problems with the OSI model is that TCP/IP is the most common protocol stack in use today, but it is older than the OSI model, so some things don't match up perfectly between the two. So it might make more sense to be at the session layer, but in TCP/IP it ends up in Layer 4 as part of TCP.

Okay, that makes more sense, thanks.