The OSI Model

The OSI, or Open System Interconnection, model defines a networking framework for implementing protocols in seven layers. Control is passed from one layer to the next, starting at the application layer in one station, proceeding to the bottom layer, over the channel to the next station and back up the hierarchy.

There are 7 Layers in the OSI Model, each describing a particular aspect of networking.

OSI Model
Application
Presentation
Session
Transport
Network
Data Link
Physical

It is an essential to memorize the layers of the OSI model and what they do.  There are two common pneumonics that are generally used, one starts at the top and the other at the bottom:

All People Seem To Need Data Processing

Please Do Not Throw Sausage Pizza Away

Either one can help you remember, but don’t forget which end you are starting on.  Now that you have them memorized, what does each layer do? Continue reading »

Posted in Networking, System Administration | Tagged , , | Leave a comment