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OSI Model
Tutoring > Operating Systems and Networks > OSI Model
Two computers communicate with each other through a series of 7 layers:
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Physical layer. This layer defines the physical hardware needed to actually transmit information between two network nodes (computers or devices).
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Data link layer. Here, data packets are encoded
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Network layer. This layer provides switching and routing technologies.
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Transport layer. This layer provides transparent transfer of data between end systems (hosts).
-
Session layer. This layer establishes, manages and terminates connections between applications.
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Presentation layer. This layer provides independence from differences in data representation (e.g. encryption) by translating from application to network format, and vice versa.
-
Application layer. This layer supports application and end-user processes.
Usually layers 5-7 are compounded into one layer.
As shown here, different protocols are employed in each
layer to manage what happens during communication.
Each layer only communicates with the layers directly
above and below it.
For example, if you accessed a web page through your
browser, starting at layer 7 the following protocols may be
used:
HTTP -> TCP -> IP -> Ethernet
