learning target:
1. Familiar with the specific content of the OSI seven-layer model;
2. Briefly understand the functions of each layer;
3. Understand how data is transferred
Learning Content:
1. OSI (open system interconnect), the full name is Open System Interconnect Reference Model. From high to low, they are application layer, presentation layer, session layer, transport layer, network layer, data link layer, and physical layer. The data communication theory we study is mainly for the network layer, data link layer, and physical layer.
The functions of each layer of the OSI model are introduced:
1. Application layer. Provides network services for applications.
2. Presentation layer. Encrypt and decrypt data at the application layer.
3. Session layer. Establish, manage, and maintain the callback link.
4. Transport layer. Establish, maintain, and manage end-to-end connections.
5. Network layer. Responsible for ip address selection and routing selection.
6. Data link layer. Controls communication between the network layer and the physical layer.
7. Physical layer. Responsible for bitstream transmission.
