OSI is known for using hundreds of protocols to do its job. Both OSI and TCP/IP have Transport and Network(Internet) layers where TCP and IP protocols work respectively. It is clear that TCP/IP model uses both TCP and IP protocols. My question is does OSI model use the same TCP and IP protocols which are used by TCP/IP model, or does it have its own protocols for that specific functions?

Thanks for your time!

3 Answers 3


The layering models don't use protocols. The layering models provide a structure to build the protocols on.

The OSI model is a very detailed and strict model. It was developed as a theoretical model (somewhat) in parallel to the growing TCP/IP or DoD model which largely came out of practice. OSI is good way to structure a protocol concept as long as you don't stick to it literally.

The DoD model pretty much throws together everything above the transport layer (=application layer) and everything below the network layer (=link layer) which may be a practical approach when concentrating on the network layer but it lacks coverage above and below when doing more complex designs.

But even OSI might not be detailed enough for every purpose. For example, Ethernet generally covers OSI's physical layer and data link layer. However, IEEE 802.3 defines up to four sublayers for the physical layer and up to three sublayers for the data link layer.


The OSI model does not specify the protocols -- only the functions. TCP and IP are defined by the TCP/IP model. See if this question helps you.


OSI - are layers, tcp/ip - are specific protocols. So, there is a difference between them.

  • 1
    The question was about the TCP/IP network layer model. This is an "alternative" to the OSI model (however I think it was developed independently of OSI). That model uses only 4 instead of 7 layers: "Link" (OSI 1+2), "Internet" (OSI 3), "Transport" (OSI 4), "Application" (OSI 5+6+7). Of course the "TCP/IP model" can also be used to describe non-IP protocols like IPX/SPX. Aug 7, 2018 at 4:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.