Question

The TCP/IP Networking Model is called a "de facto" standard, while the OSI Networking Model is called a "training standard." What does this mean and why do we have both? Support your rationale.

Answer 1

The TCP/IP suite of protocols is the current de facto standard for both local and wide area networking. It allows computers from different vendors with various operating systems and capabilities to communicate. All modern operating systems include TCP/IP support as a default selection for installing and configuring network support. It is the most widely used networking protocol suite in the world, and is the language of communication on the Internet. In addition to being used as a communication protocol on private networks, TCP/IP is required for Internet access. For one computer to communicate with another computer over a TCP/IP network, it must know the other computer's 32-bit Internet Protocol (IP) address.

The Transmission Control Protocol/Internet Protocol Suite (TCP/IP) has become the de facto standard for the Internet, and most organizations use it for network communications. TCP/IP includes both network-communication and application-support protocols. As stated earlier, the TCP/IP protocol suite was developed and in use before the ISO/OSI model was developed and, as such, does not match directly with the layers of the OSI model.

OSI (Open Systems Interconnection) is a reference model for how applications communicate over a network.

A reference model is a conceptual framework for understanding relationships. The purpose of the OSI reference model is to guide vendors and developers so the digital communication products and software programs they create can interoperate, and to facilitate a clear framework that describes the functions of a networking or telecommunication system.

Most vendors involved in telecommunications make an attempt to describe their products and services in relation to the OSI model. And although it is useful for guiding discussion and evaluation, OSI is rarely actually implemented as-is. That's because few network products or standard tools keep related functions together in well-defined layers, as is the case in the OSI model. The TCP/IP protocol suite, which defines the internet, does not map cleanly to the OSI model.

We need it because that’s the agreed upon standard.

Imagine the following scenario:

You and your neighboor decide to communicate with each other. You normally send your neighbor a box with an envelope inside. Your neighbor opens then box, finds the envelope, opens it and gets your message.

Now let’s say someone else decides to communicate with your neighbor. Instead of sending an envelope inside a box, they send an envelope inside a bag and place the bag inside the box. When your neighbor opens the box expecting an envelope, they find a bag and get confused because they don’t know what to do now (remember that computers are dumb and have to be told exactly what to do and what to expect)

The osi model standardizes what a comouter does with the “package” it receives. It tells the computer how to unpackage a package it receives to ultimately be able to read the message inside.