CHAPTER 5 The OSI Model and Networking Protocols
In 1977, the International Organization for Standardization formed a subcommittee called the Open Systems Interconnection (OSI) from which a seven-layered framework was established and is still used as the model for distributed communications. The OSI model is shown in Figure 5.1.
FIGURE 5.1 The OSI model
The first two layers of the OSI model involve both hardware and software. In the five upper layers (Layers 3 to 7), the OSI model typically is implemented via software only.
The OSI model is represented as a stack because data that is sent across the network has ...