Osi (Open Systems Interconnection) Model

OSI (Open Systems Interconnection) model

Application The application layer communicates software with the network layer so that the application layer can interpret data. The different application protocols help the software applications interpret synchronization, formatting, procedures, security, and any other requirements from the network layer. HTTP (Hypertext Transfer Protocol)

Presentation Presentation layer protocols accept data from the application layer. The presentation layer translates between different applications and hosts so that the different hosts and applications can understand one another. The presentation layer performs compressing and coding and reads data encryption so it can be managed properly. data encryption

compressing

encoding

translating

decrypting

Session The session layer coordinates communication between two nodes in the network the remote client and access server. The session layers needs to make sure the communication stays open and that it is secure during the entire session. security synchronizing the dialogue between two nodes

determining whether communications have been cut off

figuring out where to restart transmission

terminating communications

monitors the identification of session participants

ensure that only the authorized nodes can access the session

Transport The transport layer receives data from the session layer. It also makes sure that all data gets where it is supposed to go without error and in the correct order. Transport protocols will fall under one of two categories connection-oriented and connectionless. Connection-oriented protocols will make sure that data arrives exactly as it was sent. Connectionless protocols are not as important do not need to arrive exactly as sent. server accept data from the Session layer and manage end-to-end

delivery of data without errors

flow control

TCP

SYN

SYN-ACK

ACK

Network The network layer figures out where to send data by translating network...