TCP/IP Model
The network protocol used on the Internet is named TCP/IP after two of its components: TCP and IP. The TCP/IP model uses a five-layer structure (formerly a four-layer model) in its protocol suite. In the TCP/IP model, the layers have names rather than numbers.
Although sometimes people still refer to TCP/IP layers by their number, such as layer 1 or layer 4, this kind of reference is more appropriate for the OSI reference model. Layers in the TCP/IP model are not broken down from the bottom (physical) to the top (application), like the OSI model. Instead, they are grouped on the basis of functions.
The following diagram shows the layers of the TCP/IP model with some corresponding protocols and devices at each layer.
Figure 10.3: TCP/IP model with protocols
Reading from the bottom to the top, starting with the physical layer, you will notice that the layers map exactly onto the bottom four layers of the OSI model of the same name. The...
