Data and computer Communication learning notes

Data and Computer communication learning notes----

OSI (Open Systems interconnection--Open System Interconnect (Reference Model)) is the model of a layer.

Characteristics:

Each layer provides a part of the communication function.

Each layer relies on the functionality provided by the previous layer and serves the next high level.

The change of one layer does not require changes in other layers.

OSI model

Physical layer: Care for the transmission of unstructured bitstream on physical media, dealing with mechanical, electrical, functional and procedural characteristics to access physical media. (There are transponders and other devices at this level.) ）

Data Link Layer: Provide reliable information transfer across the physical layer, carry the necessary synchronization, error control, flow control and other information to send data blocks. (There are bridges, switches and other devices working at this layer)

Network layer: Provides the Exchange technology and data transfer to connect the system and the independence between the high-level, responsible for establishing, maintaining and terminating the connection. (Switches and other devices working at this layer)

Transport Layer: Provides reliable, transparent data transfer between endpoints, providing end-to-end error recovery and flow control.

Session Layer: Provides a control structure for communication between applications. Establish, manage, and terminate connections (i.e. sessions) between collaborative applications.

Presentation layer: Provides the independence between the difference between the data representation and the application process.

Application layer: Provide users with access to the OSI environment, while providing distributed information control.

Data and computer Communication learning notes