"linux Network Management"osi model

Learn Linux network management, notes collation, promote memory.

OSI (Open Systems Interconnection model) consists of seven layers, which are progressive from the application layer to the physical layer, respectively, and have different protocols and data processing methods.

Application----layer-to-session-layer-to-layer-layer---------Data link layer----physical

Data unit: ADPU PPDU SPDU TPDU message frame bit

ADPU: Application Protocol Data Unit

PPDU: Presentation layer Protocol Data Unit

SPDU: Session Protocol Data Unit

TPDU: Transfer Protocol Data Unit

This is the order in which the data is emitted, and the order in which the data is received is reversed

The data transfer between different hosts is through the physical layer.

The first three levels, regardless of whether the data transfer (network) need to be carried out, the latter four levels only for data transmission is to participate.

　　

MAC address is responsible for local network communication, IP address is responsible for external network communication

Specific features:

Application Layer: User interface

Presentation layer: Data representation, implementation of specific functions, such as encryption and decryption (Ascii,mp4 ... ）。

Session Layer: Managing the application session, synchronizing

Transport Layer: Reliable (TCP) and unreliable (UDP) transmissions, pre-transmission detection, flow control

Network layer: Provides logical address (IP), routing

Data link layer, frame, access media with MAC address, error detection and correction

Physical layer: The transmission of bits (machine language) between devices, physical interfaces, electrical characteristics, etc.

"linux Network Management"osi model