2.1. Introducing the OSI Model

The OSI model was designed to promote interoperability by creating a guideline for network data transmission between computers and components that have different hardware vendors, software, operating systems, and protocols. For example, look at the simple process of transferring a file. From a user's perspective, a single operation has been performed to transfer the file. In reality, however, many different procedures had to take place behind the scenes to accomplish this seemingly simple task. Network data transmission (like the file transfer) is performed through the use of a protocol suite, also known as a protocol stack, especially when installed in a given device.

A protocol is most easily defined as a set ...

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