Technology gets complicated when you begin to add new layers of interaction. If you have a new application that relies on multiple media layers and host layers to operate effectively, it’s hard to pin down a root cause when something goes wrong.
That’s why the OSI model, or Open Systems Interconnection Model, exists. It’s a conceptual model that’s meant to simplify and define the layers of a computing system (or telecommunication system) as abstractions in the form of communication protocols.
The OSI model enables communication by transmission across several distinct layers within a system, with current recommendations offering seven layers. Each of these layers communicate with its peers by exchanging protocol data units (PDU), or pieces of information that vary depending on which level you’re on. Within each PDU is a payload, which is called a service data unit (SDU).
You can think of these layers as being defined in terms of numbers, with 1 being the lowest layer in the system, and 7 being the highest layer in the system. Layers 1 to 3 are considered media layers, while layers 4 to 7 are considered host layers.
These are the current layers we use within the OSI model:
There are many functions that are not tied to any single layer, like security. Security controls are important at nearly every layer in this model.
You may wonder why the OSI model matters in the first place. After all, some modern systems, including the internet, don’t strictly follow the architecture of the OSI model (the internet, for example, follows the internet protocol suite).
However, for many organizations, the OSI model is the best model we have for troubleshooting network problems, which is vital for network security. If a single person or a group of people is having trouble with a tech-related issue, like being unable to reach the internet, the OSI model allows you to break down the elements of the problem, isolate the layer in which the problem exists, and eventually solve the problem.
Are you interested in learning more about the OSI model, or implementing better security across these layers in your organization? Contact Check Point Software today for a free consultation!