Comparison of the TCPIP Model and the ISOOSI Reference Model

Comparison of the TCP/IP Model and the ISO/OSI Reference Model

The ISO/OSI reference model is a seven-layer model (which includes the Physical layer), whereas the TCP/IP model is a five-layer model (if you include the Hardware layer).

The Hardware layer has been included in this discussion for comparison purposes because the ISO/OSI Reference model has always been described as a seven-layer model, one layer of which is the Physical layer, and corresponds directly with the Hardware layer of the TCP/IP model.

Figure 2.3 shows how the layers differ between the two models. Note that the Application layer in the TCP/IP model carries out the same function as three of the layers in the ISO/OSI Reference model ”the Application, Presentation, and Session layers.

Figure 2.3. TCP/IP model and ISO/OSI reference model layers.