Comparison of OSI and TCP/IP Reference Model

In this tutorial, we will cover the comparison between the two reference Models that is OSI model and the TCP/IP model in Computer networks.

Open System Interconnection (OSI) is commonly known as the OSI model.

  • The OSI Model is mainly a conceptual framework and is used to describe the functions of a networking system.

  • The OSI Model consists of seven layers where each layer performs its specific function.

  • This model was published by ISO in 1984.

  • This model mainly divides the giant task into seven manageable and smaller tasks. After that, each layer in the model is assigned a particular task.

The ISO-OSI model is a seven-layer architecture. It defines seven layers or levels in a complete communication system. They are:

  1. Application Layer

  2. Presentation Layer

  3. Session Layer

  4. Transport Layer

  5. Network Layer

  6. Datalink Layer

  7. Physical Layer

OSI Model

TCP/IP Model

TCP/IP is Transmission Control Protocol and Internet Protocol was developed by the Department of Defence's Project Research Agency (ARPA, later DARPA) as a part of a research project of network interconnection to connect remote machines.

The features that stood out during the research, which led to making the TCP/IP reference model were:

  • Support for a flexible architecture. Adding more machines to a network was easy.
  • The network was robust, and connections remained intact until the source and destination machines were functioning.

The overall idea was to allow one application on one computer to talk to(send data packets) another application running on a different computer.

TCP/IP Model

Now it's time to compare both the reference model that we have learned till now. Let's start by addressing the similarities that both of these models have.

Following are some similarities between OSI Reference Model and TCP/IP Reference Model.

  • Both have layered architecture.

  • Layers provide similar functionalities.

  • Both are protocol stack.

  • Both are reference models.

  • Both have Predefined Standards.

Difference between OSI and TCP/IP Reference Model

Following are some major differences between OSI Reference Model and TCP/IP Reference Model, with diagrammatic comparison below.

OSI(Open System Interconnection) TCP/IP(Transmission Control Protocol / Internet Protocol)
1. OSI is a generic, protocol-independent standard, acting as a communication gateway between the network and end-user. 1. TCP/IP model is based on standard protocols around which the Internet has developed. It is a communication protocol, which allows the connection of hosts over a network.
2. In the OSI model the transport layer guarantees the delivery of packets. 2. In the TCP/IP model the transport layer does not guarantee the delivery of packets. Still, the TCP/IP model is more reliable.
3. Follows vertical approach. 3. Follows horizontal approach.
4. OSI model has a separate Presentation layer and Session layer. 4. TCP/IP does not have a separate Presentation layer or Session layer.
5. Transport Layer is Connection Oriented. 5. Transport Layer is both Connection-Oriented and Connectionless.
6. Network Layer is both Connection-Oriented and Connectionless. 6. Network Layer is Connectionless.
7. OSI is a reference model around which the networks are built. Generally, it is used as a guidance tool. 7. TCP/IP model is, in a way implementation of the OSI model.
8. Network layer of the OSI model provides both connection-oriented and connectionless service. 8. The Network layer in the TCP/IP model provides connectionless service.
9. Th TCP/IP model also provides standardization to many devices such as a router, motherboard, switches, and some other hardware devices. 9.This model does not provide any such kind of standardization of the devices. But this model provides a connection between various computers
10. Protocols are hidden in the OSI model and are easily replaced as the technology changes. 10. In TCP/IP replacing protocol is not easy.
11. OSI model defines services, interfaces, and protocols very clearly and makes a clear distinction between them. It is protocol independent. 11. In TCP/IP, services, interfaces, and protocols are not clearly separated. It is also protocol-dependent.
12. It has 7 layers 12. It has 4 layers
13.The usage of the OSI reference model is low. 13.On the other hand TCP/IP model is highly used.
14.OSI model has a problem of fitting the protocols into the model. 14. TCP/IP model does not fit any protocol