OSI Layers in NDC
Upcoming SlideShare
Loading in...5

OSI Layers in NDC



Manohar Prasad,

Manohar Prasad,
Suryadatta Institute of Management, Pune



Total Views
Slideshare-icon Views on SlideShare
Embed Views



3 Embeds 5

https://twitter.com 3
http://www.linkedin.com 1
https://www.linkedin.com 1



Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
Post Comment
Edit your comment

    OSI Layers in NDC OSI Layers in NDC Presentation Transcript

    • OSI Layers
      By- Manohar Prasad.
    • Introduction:
      The Open Systems Interconnection (OSI) model describes how information from a software application in one computer moves through a network medium to a software application in another Computer.
      It divides the communications processes into seven layers.
      It is a theoretical representation of what happens between two nodes communicating on a network.
      Manohar Prasad.
    • 7 Layers:
      The Seven Layers of the OSI Model can be divided into two categories:
      • Upper Layer.
      • Lower Layer.
      The Upper Layers of the OSI Model deal with application issues and are generally implemented only in Software.
      The Lower Layers of the OSI Model handle data transport issues and are implemented in hardware and Software.
      Manohar Prasad.
    • 1. Physical Layer:
      The Physical Layer of the OSI Model defines connecter & interface specifications, as well as medium requirements.
      Protocols at the Physical Layer accept frames from the Data Link Layer & transmit signals.
      When receiving data, physical layer protocols detect & accept signals and pass on to the Data Link Layer.
      Connectivity devices such as Hubs and Repeaters operate at the Physical Layer.
      Physical Layer protocols also set the data transmission rate.
      Manohar Prasad.
    • 2. Data Link Layer:
      The primary function of the Data Link Layer is to divide data received from the Network Layer into distinct frames that can be transmitted by the Physical Layer.
      The Data Link Layer is divided into two sublayers:
      • The Upper sublayer of the Data Link Layer, called the Logical Link Control, provides an interface to the Network Layer protocols , manages flow control & issues requests for transmission of data.
      • The Lower sublayer of the Data Link Layer, called the Media Access Control manages access to the Physical medium.
      Ex. A Network Interface Card having MAC address.
      Manohar Prasad.
    • 3. Network Layer:
      The primary function of the network layer is to translate network address into their physical counter parts & decide how to route data from the sender to the receiver.
      Each node has two types of addresses:
      (a) Network address (b) Physical address
      Network layer protocols determine the path from point A on one network to point B on another network by:
      (a)Delivery priorities (b)Network congestion.
      Manohar Prasad.
    • 4. Transport Layer
      The transport layer accepts data from session layer & manages the end-to-end delivery of data.
      It breaks large data units into multiple smaller units, called segments.
      Generally, it is responsible for making sure that the data is delivered error-free & in proper sequence.
      Some transport layer protocols known as connection-oriented take steps to ensure that the data arrives exactly as it was sent.
      Manohar Prasad.
    • 5. Session Layer
      The session layer, provides various services, including tracking the number of bytes that each end of the session has acknowledged receiving from the other end of the session. It allows applications functioning on devices to establish, manage, and terminate a dialog through a network. Session layer functionality includes:
      Virtual connection between application entities
      Synchronization of data flow
      Creation of dialog units
      Connection parameter negotiations
      Partitioning of services into functional groups
      Acknowledgements of data received during a session
      Retransmission of data if it is not received by a device
      Manohar Prasad.
    • 6. Presentation Layer
      The presentation layer, is responsible for how an application formats the data to be sent out onto the network. The presentation layer allows an application to read (or understand) the message.
      Examples of presentation layer functionality include:
      • Encryption(such as the scrambling of passwords) and decryption of a data for security.
      • Compression and expansion of a data so that it travels efficiently.
      • Graphics formatting.
      • Content translation.
      • System-specific translation.
      Manohar Prasad.
    • 7.Application Layer
      The application layer, provides an interface for the end user operating a device connected to a network.
      This layer is what the user sees, in terms of loading an application (such as Web browser or e-mail); that is, this application layer is the data the user views while using these applications.
      Examples of application layer functionality include:
      • Support for file transfers.
      • Ability to print on a network.
      • Electronic mail.
      • Electronic messaging.
      • Browsing the World Wide Web.
      Manohar Prasad.
    • Thanks !
      Manohar Prasad.