open system interconnection

Learn what the Open Systems Interconnection (OSI) reference model is and how its seven layers of functions provide vendors and developers with a common language for discussing how messages should be transmitted between any two points in a telecommunication network.
: Instead of serving as protocol, the OSI model has become a teaching tool that shows how different tasks within a network should be handled in order to promote error-free data transmission.

An Introduction to the OSI ModelSource: Flickr/jonjohnson
The open system interconnection model, better known as the OSI model, is a network map that was originally developed as a universal standard for creating networks. But instead of serving as a model with agreed-upon protocols that would be used worldwide, the OSI model has become a teaching tool that shows how different tasks within a network should be handled in order to promote error-free data transmission.

These jobs are split into seven layers, each of which depends on the function’s “handed-off” from other layers. As a result, the OSI model also provides a guide for troubleshooting network problems by tracking them down to a specific layer. Here we’ll take a look at the layers of the OSI model and what functions they perform within a network.

1. SUBJECT: COMPUTER NETWORKS TOPIC: OSI MODEL CREATED BY : RUCHI MAURYA TWINKAL PARMAR SHIVALI SALUNKHE

2. OPEN SYSTEM INTERCONNECTION

3. OSI –open system interconnection model. Conceptual model. Developed by ISO in  1984 . ISO : Dedicated to defining global communication and standards. logical framework Introduction

4. 7 Layers Of OSI Model

5. Top layer serve as window Interface between programme and protocol stack. Enable to access network. 7. Application Layer

6. 7. Application Layer To Presentation Layer From Presentation Layer

7. Network virtual terminal File transfer , access and management Mail services 7. Application Layer Functions:

8. Also called  Translation layer . concerned with syntax and semantics of the information It can be viewed as the translator for the network. translate data from a format into a common format then translate the common format to a format . Manages data-format information. 6. Presentation Layer

9. 110011000111 H6 110011000111 H6 From Application Layer To Application Layer To Session Layer From Session Layer 6. Presentation Layer

10. 6. Presentation Layer Functions: Character code Translation Data Conversion Data Compression Data Encryption

11. hold ongoing communications (called a session) across a network. orderly communication defines the  format of the data   establish and manages the session   reconnect the session if it disconnects. 5. Session Layer

12. H5 syn syn syn From Presentation Layer To Transport Layer Session Layer From Transport Layer To Presentation Layer H5 syn syn syn Session Layer 5. Session Layer

13. Session establishment, maintenance and termination. Dialog Control security and access control Synchronization 5. Session Layer Functions:

14. End to end message delivery Error checking No duplication or errors are occurring Message arrive in order Acknowledgement Retransmits the data if error is found 4. Transport Layer

15. 4. Transport Layer

16. Message acknowledgment Message traffic control Session multiplexing Flow control 4. Transport Layer Functions:

17. source to destination delivery. across multiple networks (links). converting logical addresses into physical addresses. determines that how data transmits between the network devices. Handles addressing messages for delivery. 3. Network Layer

18. deciding how to route transmissions between computers 3. Network Layer 110011000111 H3 110011000111 H3 From Transport Layer To Transport Layer To Data Link Layer From Data Link Layer Packet Packet

19. Logical-Physical Address Mapping Internetworking Logical Addressing Routing Packetizing Fragmentation 3. Network Layer Functions:

20. provides a reliable link node-to-node delivery Handles special data frames (packets) error-free transfer  defines the format of data 2. Data Link Layer

21. Data Link layer consists of two sub-layers: 1. Logical Link Control (LLC) sublayer 2. Medium Access Control (MAC) sublayer 2. Data Link Layer 110011000111 H2 T2 110011000111 H2 T2 From Network Layer To Network Layer To Physical Layer From Physical Layer Frame Frame

22. Framing Physical Addressing Flow Control Error Control Access Control 2. Data Link Layer Functions:

23. Lowest Layer Transmitting individual bits Mechanical electrical specification 1. Physical Layer Transmission Media 110011000111 110011000111 H1 H1

24. Bit representation Transmission rate Synchronizing Transmission mode Physical Topology 1. Physical Layer Functions:

25. Thank You !!