• A description of how the Internet works. It breaks down the functions involved in sending data over the Internet into seven layers. Each layer has some function that prepares the data to be sent over wires, cables, and radio waves as a series of bits


OSI is an abstract conceptualization of the processes that make the Internet work, and interpreting and applying the model to the real-world Internet is sometimes a subjective exercise.

The OSI model is useful for helping people talk about networking equipment and Network Protocol, determining which protocols are used by which software and hardware, and showing roughly how the Internet works. But it is not a rigid step-by-step definition of how Internet connections always function.

OSI Application Layer

  • Has access to all the Data

OSI Transport Layer

  • Only know 2 pieces of info - IP Address & Network Port
  • It is pointless to look at the data, because it is just stream of Bit and may be encrypted with TLS