[ELI5] How the TCP/IP 5-layer model works in detail


[ELI5] How the TCP/IP 5-layer model works in detail

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The 5 layer TCP/IP model is a simplification of the 7 layer OSI model, but in essence it is the same and it is used for communication on computer networks to split up specific tasks in distinct modules.


When your webbrowser communicates with a server, the communication is happening between these layers. At least on each end, and depending on the network infrastructure also several times in the communication path.

It doesn’t have to be a webbrowser/webserver, it applies to any application.

A communication flow goes from application layer to network access layer on one end, and from network application layer to application layer on the other end. Reply traffic goes the opposite direction.

Each layer is independant, has a well defined role and responsibility, and will handover communication to the next layer. This ensures each layer is modular and can be swapped out for a different technology with the same function.

Example: Your webbrowser software (application layer) doesn’t (need to) know(s) about the network access layer and will happily communicate if you use a cabled network, wireless or celular network. (It is irrelevant.)
Your wireless network (network access layer) will happily transfer data and doesn’t care what webbrowser (Edge, Chrome, …) you use in the application layer.

This is a fundamental concept in making the internet work and the opposite of a self contained, proprietary communication system.