TCP/IP
While the OSI model is theoretical, TCP/IP is a practical implementation of a set of protocols that dominates the current networking environment. TCP/IP was created by the United States Department of Defense (DoD) with the intention of creating a protocol that would ensure the integrity of communications in the event of a catastrophe. Therefore, the TCP/IP is also referred to as the DoD model and is made up of the following four layers:
- Application
- Transport
- Internet
- Link/network access
It can be mapped to the different OSI model layers as shown in Figure 11.4.
Figure 11.4: The TCP/IP model compared to the OSI model
The link/network access layer corresponds with the OSI model’s physical and data link layers. This layer defines how the networking device will connect to the network.
The Internet layer corresponds with the network layer of the OSI model. This layer is responsible for the logical addressing and routing...