The TCP/IP Model

Now let’s examine the TCP/IP Model.


  • The Internet protocol suite, sometimes referred to as the TCP/IP Model, was created in 1989.
  • The Defense Advanced Research Projects Agency (DARPA), formerly known as the Advanced Research Projects Agency (ARPA), provided funding for its creation.
  • RFC 1122 provides precise technical information about it.
  • The Internet Protocol (IP) and the Transmission Control Protocol are the two Internet protocols on which this paradigm is principally built (TCP).
  • Unlike the OSI model, each layer’s protocols are well-defined. We’ll follow the TCP/IP paradigm and adopt a protocol-focused methodology.

The Layers of The TCP/IP Stack

A communication system is divided into five abstract layers that are built on top of one another by the TCP/IP architecture. Each layer carries out a certain function and interacts with the layers above and below it.

The five components of the TCP/IP model are as follows:

TCP/IP model
TCP/IP Model Network Stack


Main Differences

The key differences between TCP/IP and OSI are listed below.

Is practically employedThe OSI model is theoretical and not utilized in actual communication.
It has five layersIt has seven layers
  • To further on the first issue, OSI is a theoretical model that is excellent for teaching but is simply too sophisticated for anybody to put into practice.
  • Contrarily, TCP/IP wasn’t actually a model. People just put it into practice and made it function. In order to provide a reference model for theoretical and educational reasons, it was later reverse-engineered. Therefore, a fantastic concept that “sounds” terrific may not really win.

Differences in Layer Functionality

The TCP/IP stack’s layers mainly carry out the same tasks as their equivalents in the OSI model, with the exception that the application layer in the TCP/IP model includes the features of the top three OSI model levels.

For a better understanding, have a look at the diagram below.

The Network Stack
The Network Stack

No Unanimous Stack Exists

In this case, primary sources like RFCs and secondary ones like textbooks are at odds. In fact, Wikipedia has a whole table devoted to the famous layer stacks! Whatever the case, we’ll continue to use the TCP/IP paradigm.

The End-To-End Argument in System Design

The end-to-end argument, commonly known as the following design choice, has a significant impact on the TCP/IP protocol suite.

Since it would be too costly to put intelligence at the core, intelligence was instead applied at edge devices. Therefore, the Internet was created with sophisticated end devices and a core network that was dumb and quick.

Packet Switched Core

Additionally, since resilience was required, the core was converted to packet switching, which entails that packets are routed per hop so they may avoid failures.

However, if there is still a way in circuit-switched networks, broken connections must be re-established.

Gaurav Karwayun is the founder and editor in chief of CodeIntelligent. He has over 10+ Years of Experience in the software industry. He has experience working in both service and product-based companies. He has vast experience in all popular programming languages, DevOps, Cloud Computing, etc. Follow him on Twitter.

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