Visual C + + network programming--Notes

The first part: basic knowledge

1.OSI seven-layer network model: The OSI network model is a reference model for open Systems interconnection. It includes 1, physical hardware layer, 2, Data link layer, 3, network layer, 4, data transmission layer, 5, Session layer, 6, presentation layer, 7, application layer. At the sending end of the network communication, the communication data of each communication layer is added to the data by the layer protocol, and the receiver is the opposite, the data through each layer will be stripped of the corresponding packet header data.

Definition of each network layer

Physical hardware layer: As the name implies, the corresponding physical devices, such as network cards, etc.

Data link layer: Compress and compress data

Network layer: Transfer data for network transmission

Data transfer layer: Network transmission of information

Session Layer: Establishing a connection to a physical network

Presentation layer: Transmits data in a format

Application Layer: Application interface

2.TCP/IP protocol

The network model of TCP/IP protocol is only 4 layers, including data link layer, network layer, data transmission layer and application layer.

Each network layer definition

Data Link layer: Network hardware devices such as NIC and drivers

Network layer: IP protocol and other interconnection protocols

Data transfer layer: Provides communication methods for the application, usually the TCP/UDP protocol

Application layer: Responsible for processing the actual application layer protocol

3.C/S programming Model

Listening process: The server waits for the arrival of the client connection request (on a specific IP address and port);

Visual C + + network programming--Notes