Python road pythonnet, first, network 1

Pythonnet Network 1

ARPAnet (Internet embryonic)---> Civil

ISO (International Organization for Standardization)---> Network Architecture standard OSI model

OSI: Network information transmission complexity requires a lot of functional collaboration---separating functions, reducing coupling, and allowing each module to perform certain functions

---> Combine these modules in a certain order, complete the function, clear the conditioning.

Sequential architecture According to mandated functions: OSI model

OSI Seven layer Model:

Application tiers: Provide user services such as processing applications, file transfers, data management

Presentation layer: Do data conversion and compression, decompression, encryption, etc.

Session Layer: Determines the inter-process connection establishment and chooses what Transport layer protocol to use

Transport Layer: Establish network connection, provide appropriate connection transmission service, provide flow control;

Network layer: Control packet transmission, routing, network interconnection;

Link Layer: Provides the link exchange, the specific data send and receive;

Physical layer: Physical hardware, specific transmission conditions and transmission interface;

Actual operation: four-layer model

Application layer: Application layer, presentation layer, Session layer

Transport Layer: Transport Layer

Network layer: Network layer

Physical link layer: Link layer, physical layer

Seven-storey-----"

Four layers

Application tier (contains the application layer presentation layer session layer)
Transport Layer
Network layer
Physical link layer (includes link layer and physical layer)

Five tiers (TCP/IP model)

Application tier (contains the application layer presentation layer session layer)
Transport Layer
Network layer
Link Layer
Physical Layer

Protocol: Network protocol, a few in the network transmission process in order to ensure that the communication is normal and customized to abide by the Convention;

Python road pythonnet, first, network 1