Network Fundamentals
In this document, I will try to include as much information about Networking basics such as layers, protocols, devices, operations, functions, and other data. I thought of many ways to split this material and I think the best way is to have it done over the OSI model and explain everything I can within each OSI Layer of course with providing some visual explanations when I can.
Introduction to the OSI Model
I will keep the introduction very clear and simple and I will follow with more detailed explanations on each layer focusing on the first 4 layers of the OSI Model.
What is the OSI Model and its Layers?
OSI stands for Open Systems Interconnections and it is a concept created to simplify and standardize the communication functions of telecommunication or computing system.
The OSI Model 7 Layers
One of the famous mnemonic phrases you can use to remember this model is “Please Do Not Throw Sausage Pizza Away” which starts at Layer 1 and moves towards Layer 7.
It’s not all about the OSI Model
We have other Models in this universe and the other model is the TCP/IP Model (Transmission Control Protocol / Internet protocol), I thought I should add in a representation of how they both compare and what do we call layers in these two different models.
You can see each Layer of each Model and what it equates to on its neighboring Model
Data Encapsulation / PDUs
The below is a representation of the Data Encapsulation and Protocol Data Unit of the Ethernet Frame
OSI - OS Level
This will give you an idea of which portion of the Network Adapter settings in Windows environment are represented by which Layer on the OSI Model
TCP/IP Quick Guide
extra resource: