OSI Model

[Physical Quantity(Radiowave, Electric signal, Infrared Signal, etc)]

1: Physical Layer: converts data into physical quantity so that it can be physically transmitted

>Wi-fi chip, ethernet port and cable, etc

[Packets]

2. Data Link Layer: Manages data transfer between directly connected nodes such as error detection or flow control

  - MAC Layer: controls how device gains access to medium and permission to use network

  - LLC Layer: identifies and encapsualtes Network Layer Protocol(Not whole), check error and synchornizes frames

[Packets]

3. Network Layer: Forwards received packet to another adjacent node, which enables "network"(in contrast to 1:1 communication)

 - Router conducts routing in this layer

[Segments]

4. Transport Layer: segments data and grants sequence number to them.

  - One of the most important layers.

  - Converts data into binary, segments and grants sequence and etc


5. Session Layer: manages the session between end and the another end

[Text]

6. Presentation Layer: formats and translates data. also encrypt/decrypts the data

 > MIME belongs to this layer

[HTTP Request]

7. Application Layer: application that end user uses







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Leetcode

이미지
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