June 02, 2011

At-a-Glance: OSI Model

Why should I Care About the OSI Model?

The OSI model serves as a guideline for creating and implementing network standards, devices, and internetworking schemes. Advantages of using the OSI model include the following:
  • Breaks up interrelated aspects of network operation into less-complex elements.
  • Enables companies and individual engineers to specialize design and development efforts on modular functions.
  • Provides standard interfaces for plug-and-play compatibility and multivendor integration.
  • Abstracts different layers of the network from each other to provide easier adoption of new technologies within a layer.


Develop mnemonics to help you memorize the layers and their order. Here's an example:
Please Do Not Throw Sausage Pizza Away

What Problems Need to Be Solved?

OSI layers can communicate only with the layer directly above or below it on the stack, and with its peer layer on another device. A process must be used so that information can be passed down the stack, across the network, and back up the stack on the peer device.