OSI Layers – Study Materials


OSI Layers – Study Materials

OSI layers

The Open System Interconnection (OSI) model defines a networking framework to implement protocols in seven layers. Use this handy guide to compare the different layers of the OSI model and understand how they interact with each other.

The Open System Interconnection (OSI) model defines a networking framework to implement protocols in seven layers. There is really nothing to the OSI model. In fact, it’s not even tangible. The OSI model doesn’t perform any functions in the networking process. It is a conceptual framework so we can better understand complex interactions that are happening.

Who Developed the OSI Model?

The International Standards Organization (ISO) developed the Open Systems Interconnection (OSI) model. It divides network communication into seven layers. Layers 1-4 are considered the lower layers, and mostly concern themselves with moving data around. Layers 5-7, the upper layers, contain application-level data. Networks operate on one basic principle: “pass it on.” Each layer takes care of a very specific job, and then passes the data onto the next layer.

The 7 Layers of the OSI

In the OSI model, control is passed from one layer to the next, starting at the application layer (Layer 7) in one station, and proceeding to the bottom layer, over the channel to the next station and back up the hierarchy. The OSI model takes the task of inter-networking and divides that up into what is referred to as a vertical stack that consists of the following 7 layers.

Note: Click each hyperlink in the list below to read detailed information and examples of each layer or continue scrolling to read the full article:

  • Layer 7 – Application
  • Layer 6 – Presentation
  • Layer 5 – Session
  • Layer 4 – Transport
  • Layer 3 – Network
  • Layer 2 – Data Link
  • Layer 1 – Physical

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