The document discusses the OSI model, which consists of 7 layers used as a framework for networking communication. It describes each layer in the OSI model from the physical layer, which deals with physically moving data, to the application layer, which acts as an interface for interacting with the network. The layers are grouped according to their functional similarities and both the sender and receiver implement the model to enable end-to-end communication across a network.

1. DATA COMMUCATION
NETWORKING AND SECURITY
BY-PRAMOD SHARMA

2. OSI MODEL
INTRODUCTION:-
1.The OSI model and TCP/IP model are two standard example of
Protocol models used for communication.
2.The OSI model consists of 7 layers.
3.OSI model is usually used as a reference model.
4.The OSI was created as a framework and reference model to explain how
different networking technologies work together.

3. OSI Model Design
Application Layer
Presentation Layer
Session Layer
Transport Layer
Network Layer
Data Link Layer
Physical Layer

4. Layers in the OSI Model
• The Layers in the OSI model are tasks grouped according
to their functional similarities.
• Both the sender and receiver implement the model.

5. Physical Layer
• Deals with the all aspects of physically moving data from one computer to
the next.
• Convert data from upper layered into 1s and 0s for transmission over media.
• Type of communication – point to point communication or multipoint.
• Transmission mode – simplex , duplex , or half-duplex , topology.

6. DataLink Layer
• It is responsible for moving frames from node to node or computer to
computer.
• It can move frames from one adjusant computer to another , cannot move
frames across the router.
• It requires the MAC address.

7. Network Layer
• The most important function of these layer is source to destination delivery.
• Its is responsible for moving packets from end of the network to other
called as end to end communication.
• It requires IP address (Logical Address).
• It also routes the data to the destination.

8. Transport Layer
• t take data from higher level of OSI model and breaks into the segment that
can be send to lower level f OSI model for the data transmission.
• Also put segments in correct order its called as sequencing.
• It may used connection orientation protocol.
• It use port address.

9. Session Layer
• It is responsible for manage a networking devices.
• It establish manage and terminate connection.
• It provides duplex , half duplex , full duplex.

10. Presentation layer
• It concern with how the data is presented to the network.
• It handles the primary task translation compression , encryption
• Translation:-changes the data in such a format that another computer can
understand it.
• Compression:-makes data smaller to send more data in same amount of time.
• Encryption:-encode the data to prevent from interception.

11. Application Layer
• The application layer acts as an interface for interacting with the network.
• It consists of application needed to access the network and for transmitting
the data.
• It consists all services needed by the application to communicate on a
networking.

12. THE END