Author: WYF
Explanation of OSI seven-layer protocol
The figure can be divided into seven layers from bottom to top
Physical layer : For example, when our computer is connected to a network cable, the process of transmitting computer data through the network cable is the physical layer, which is equivalent to a transmission medium, such as network cables, optical fibers, and cables. It is to define some characteristics of network cables and optical fibers.
Data link layer : The function of the data link layer is the form in which these data are transmitted at the bottom of our layer. For example, network cables use electrical signals, and optical fibers use optical signals to propagate. And the mac address is a protocol
network layer belonging to the link layer : in the network layer, it is to transmit a data, which is equivalent to a map. Its function is to find the best transmission path on the map, such as our IP protocol .
Transport layer : It implements an end-to-end connection (equivalent to a connection between two devices), and another function is to ensure its reliability, such as our tcp protocol.
Conversation layer: It establishes the dialogue
presentation layer between applications : its role is to encrypt and format, here is a encapsulation process, and similarly there is a decapsulation process, which is decryption. After decryption, it will be displayed.
Application layer : It provides network services for application processes. All programs that can generate traffic belong to the application layer