Functions of OSI Layers Seven Layers in OSI: Introduction to OSI, Layers in OSI and Importance of 7 Layers in OSI

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Functions of OSI Layers: Seven Layers in OSI (Computer Science)

Topics

  1. Introduction on OSI

  2. Seven layers of OSI

  3. Functions of OSI layers

  4. Name of unit exchanged in different layers

Introduction on OSI

  • OSI stands for ‘Open System Interconnection’

  • It was established in 1970 by ISO i.e. International Standards Organisation .

  • It is an ‘open source’ structure which means that it can be openly used for any environment and network easily for communication purpose.

  • It is a seven layered structured architecture.

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Image of Introduction on OSI

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Functions of Seven Layers of OSI

1)Physical Layer:

  • Physical layer is responsible for movement of bits from one node to another.

  • Hardware cabling, wireless or wireline, everything is defined here.

Image of Physical Layer

Image of Physical Layer

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  • Synchronization of bits is also concerned here.

2) Data Link Layer:

  • It divides stream of bits received from network layer into units called frames.

  • It is also responsible for :

  • Flow control

  • Error control

  • Access control

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    Image of Data Link Layer

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It is also responsible for physical addressing of frames.

3) Network Layer:

  • It is responsible for source to destination delivery of a packets across various networks.

  • It is also responsible for :

  • Logical addressing

  • Routing

  • Switching

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Image of Network Layer

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4) Transport Layer:

  • It is responsible for :

  • Segmentation with sequence numbers

  • Reassembly of segments

  • Connection control

  • Flow control

  • Error control

  • Delivery of Message from one process to another

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Image of Transport Layer

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5) Session Layer:

  • It is responsible for:

  • Dialog Control

  • Synchronization

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Image of Session Layer

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6) Presentation Layer:

  • It is responsible for :

  • Translation(for encoding scheme)

  • Encryption

  • Compression

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Image of Presentation Layer

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7) Application Layer:

  • It is responsible for:

  • File transfer

  • Management

  • Directory services

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Image of Application Layer

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#OSI Layers

#Function of Physical Layer

#Function of Data Link Layer

#Function of Network Layer

#Function of Transport Layer

#Function of Session Layer

#Function of Presentation Layer

#Function of Application Layer