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The OSI Model

The OSI Model
The OSI model describes how data flows in a network. From the top, highest level containing applications for the everyday user down to the bottom level of the physical connections, data and information passes through every layer which in turn can talk to the layers above and below it. Every layer is made up of complicated software. When that software and its components receive information, commonly called packets, from another source it checks it and then sends it back through if necessary (Breithaupt & Merkow, 2006, Chapter 12). The OSI Model is comprised of seven layers, each distinctly different but yet each function and communicate with the others.
Application layer The application layer is the one most computer users are the most familiar with, whether it is known to them or not. This is where user forward software operates, such as e-mail and the beloved World Wide Web. The application layer handles resources, files, and verifications necessary for these things to operate.
Presentation layer
The presentation layer is aptly named. Its main function is to present decrypted or encrypted data to the application layer. Examples of this process include viewing video streams or listening to music online.
Session layer
The session layer creates a session, or connection between processes running between two separate workstations or platforms. A session includes creating the connection between the systems and eventually terminating that connection at the appropriate time. This layer also handles any restart and recovery functions necessary.
Transport layer
The transport layer provides integrity for point-to-point data transmissions. The transmission control protocol lives in this layer, working to allow the connecting of two computers with each other. During this connection the computers will stream data to

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