OSI Model Advantages and Basic Purpose Explained

This tutorial explains the advantages of OSI model and TCP/IP model in detail. Learn why the OSI Model and the TCP/IP Model were created along with the purposes of OSI model and TCP/IP model.

A networking model describes how information is transferred from one networking component to another. Just like a house blueprint defines the materials and technologies that are used in constructing the house, a networking model defines the protocols and devices that are required in building the network.

Technically, a networking model is a comprehensive set of documents that describes how everything should happen in network. Individually, each document describes a functionality, protocol or device that is required by a small portion of network.

Why were the OSI Model and TCP Model created?

In starting days of computer networking, vendors created proprietary networking models to support their own products. The biggest problem with these models was that they allowed communication only between the devices those were manufactured by the same vendor. For example, a computer manufactured by the IBM was able to communicate only with the computer or networking device that was also manufactured by the IBM.

This situation was neither good nor profitable for both manufacturers and consumers. It not only forced manufacturers to make all essential networking devices but also forced consumers to buy all devices from the same manufacturer.

To break through this barrier, leading hardware manufactures agreed to use or support a vendor neutral networking model along with their own proprietary networking model in devices. To create a vendor neutral networking model, two major efforts were made.

The first one was made by ISO and second one was made by DoD. ISO (The International Organization for Standardization) created the OSI (Open Systems Interconnection) model and DoD (U.S. Department of Defense) created the TCP/IP model.

Purposes of OSI model and TCP/IP model

Both models were created for following purposes:-

  • To standardize data networking protocols to allow communication between all networking devices across the entire planet.
  • To create a common platform for software developers and hardware manufactures that encourage the creation of networking products that can communicate with each other over the network.
  • To help network administrators by dividing large data exchange process in smaller segments. Smaller segments are easier to understand, manage and troubleshoot. With layered approach they only have to troubleshoot the devices which are working in faulty layer.
TCP/IP model wins the race

Development of both models was started in early 1970s. Both were published in 1980s. Manufacturers added support for one or both in their devices in 1990s. By the end of 1990s, TCP/IP model became common choice and OSI model rejected due to slower formal standardization process in comparison of TCP/IP model. Leading manufacturers discarded their proprietary networking models in favor of TCP/IP model in 2000s. Now to world of computer networking uses only the one networking model and that is the TCP/IP model.

Why OSI model is still taught in networking courses?

In terms of explanation and documentation, TCP/IP model stands nowhere near the OSI model. OSI model is one of the best explained and well-documented models ever created in computer networking world. It describes complex networking concepts, protocols and terms in such a manner that is not only easy to understand but also easier to remember.

Since both TCP/IP and OSI model were created to achieve the same goal, they both use the same set of open standard protocols and describe the networking concepts in similar manner. By learning one model we can easily learn the other.

For this reason even OSI model is no longer supported and used by hardware manufacturers, still it is taught in almost all networking courses. Once students are learned the OSI model, they are introduced with the TCP/IP model. Since they have been already learned the foundation topics and layered approach from OSI model, learning TCP/IP model becomes much easier for them.

Layered approach

Layered approach is the hierarchical way to address all required technologies and devices in effective communication. It divides entire communication process in layers. Each layer describes a particular functionality along with the protocols and devices which are required to perform that functionality.

Both models use this approach. OSI model uses seven layers while TCP/IP model uses five layers. This layered approach allows vendors and manufactures to build and design specific applications and hardware in one layer for one purpose without affecting the entire network protocol stack.

Advantages of OSI Model and TCP/IP Model

The advantages of OSI Model and TCP/IP Model are following: -

  • Help network administrators in determining the required hardware and software to build their network.
  • Encourage hardware manufactures to create the networking products that can communicate with one another over a network.
  • Provide a teaching tool to understand the communication process used between networking components.
  • Separate a complex function into simpler components.
  • Make troubleshooting easier as network administrators can troubleshoot issue more quickly and effectually by looking in layer that is causing issue rather than finding it entire network.

advantage of OSI Layer model

That’s all for this part. This tutorial is the first part of the article “OSI Model and TCP/IP Model explained with layers”. In next part we will learn the OSI model and its layers in detail. If you like this tutorial, please don’t forget to share it with friends through your favorite social platform.

ComputerNetworkingNotes CCNA Study Guide OSI Model Advantages and Basic Purpose Explained