OSI Reference Model
The International Organization for Standardization (ISO) started developing the seven-layer OSI model back in the late 1970s, and it became a working model in the 1980s. This OSI model was intended to be a fully operational network model with all the essential networking protocols packed into a unified stack, enabling network-connected devices to communicate and share resources.
Each layer of the OSI model has a unique role and function and enables network professionals to better understand what is happening during the exchange of data from one system to another and identify network-related issues while performing troubleshooting.
Table 1.1 shows the seven layers of the OSI model:
|
Layer |
Name |
Protocol Data Unit (PDU) |
|---|---|---|
|
7 |
Application |
Data |
|
6 ... |
