Tell me about the seven-layer ISO model?

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Answer: Application Layer-> Express Layer-> Dialogue Layer-> Layer-Layer-> Network Layer-> Data Link Layers-> Physical Layer
applications layer: by the user,Provides some form of news transfer between each statementIt includes mutual visit protocols, distributed database protocols, etc. For example, a common protocol:HTTP protocol(Hypertext Transfer Protocol).

represent classStandard transmission formatThe essence is based on user needs, configured as much as possible, such as transmission of compression files, JPEG or encrypted files.

shareUsed to create and break up sessionsEntity The computer received the data sent, but there are many operations. Any process that should use this data, it sends it to that process.

ConversionResponsible for passing messages from the session layer to the network layerEssence modules are artificial, dividing into sections of information one by one, and distributing packages from them. In combination with the above levels, we can send the correct data to the computer. There are two important protocols in the transport layer:TCP and UDP

network layerLocating IP and routingEntity Common network layer protocols include IP, ICMP, and ARP. The first two levels are that the data can be sent and the data sent is valid. However, if two computers are fine and multiple computers want one to connect, then you need toguidanceSelective poetry The essence, each computer must have its own identity, so IP protocols appear.

data transfer linkProvide media access and contact management

physical classStandards for some electromechanical propertiesIt also includes working methods such as double work (telephone), one time work (printer) or semi-personal workers (transportation machines), establishing the beginning and end of communication.

Reference site:

memory method:Heir to the Eagle Suggestion Society, Wang Shu

Determine the request-response format passed between two applications? this isapplications layerResponsible stuff Do you need to specify the conversion format then? This refers to class; Then a session layer is needed to create a session; the transmission layer goes to the network layer, and then goes through the data link; The bottom layer also requires the physical layer to indicate some of the physical layers of the questionnaire equipment.

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