About presentation: Hello guys this presentation is about OSI model this can help you to make presentation of OSI model

1. ❖ Representedby:
Fizza shehwar
OSI ModelOSI Model

2. ❑ The OSI model:
❖International standard organization (ISO) established a committee
in 1977 to develop an architecture for systems communication..
❖Open system interconnection (OSI) reference model is the result of
this effort ..
❖This model allows any two different system to communicate even if
their architectures are different ..
❖It divides network communication into seven layers. Layers 1-4 are
called the lower layers and layers 5-7 called upper layers

3. Application
OSI Model Advantages
Presentation
Session
Transport
Network
Data link
Physical
Reduces complexity
Standardizes interfaces
Facilitates modular engineering
Accelerates evolution
Simplifies teaching and learning
Provides interoperability between vendors

4. Seven layers of the OSI model
Application
Presentation
Session
Transport
Network
Data link
Physical
Layer 7
Layer 6
Layer 5
Layer 4
Layer 3
Layer 2
Layer 1

5. The layers of the OSI model some Mnemonics
Application
Presentation
Session
Transport
Network
Data link
Physical
All
People
Seem
To
Need
Data
Processing
Please
Do
Not
Tell
Secret
Password
Anytime

6. Layered Approach
Layer 7
Layer 6
Layer 5
Layer 4
Layer 3
Layer 2
Layer 1 Layer 1
Layer 2
Layer 4
Layer 5
Layer 6
Layer 3
Layer 7
❖ Host 1 ❖ Host 2
Physical medium
Layer 7 protocol
Layer 6 protocol
Layer 5 protocol
Layer 4 protocol
Layer 3 protocol
Layer 2 protocol
Layer 1 protocol
Peers

7. Physical Layer
➢ Physical layer is the bottom layer(1) of OSI model
➢ It is responsible for the actual physical connection
between the devices
➢ It is responsible for movements of individual bit from
one node to next
➢ It defines the direction of transmission between two
devices(simplex, half duplex or full duplex)
➢ It defines the attachment of communication devices
with medium
➢ The common protocols are used at this level are
IEEE802,IEEE802.2,FDDI...
➢ It is responsible for the representationof Bits
Application
Presentation
Session
Transport
Network
Data link
Physical

8. Transmission of data to & from Physical Layer
10010010100110001 10010010100110001110110
From data link layer To data link layer
Physical
layer
Physical
layer
Transmission medium

9. Data link layer
➢ Data link layer is responsible for delivery of data
between to system on the same network
➢ It make sure the appropriate physical protocol is
assigned to the data
➢ It is the second layer in the OSI model
➢ It forms frames from the packets that are received form
network layer and physical layer
➢ It synchronizes the information is to be transmitted over
the data . Error controlling is easily done
➢ It's main functions are to deal with transmission errors ,
regulate the flow of data , and provide a well-defined
interface to the network layer
➢ Feedback is the function of data link layer
Application​
Presentation​
Session​
Transport​
Network​
Data link​
Physical​

10. frames
Data link layer
Data DataT2 TT2 T2 TT2
From network layer To network layer
Data link layer Data link layer
To physical layer Form physical layer

11. Network layer
➢ The network layer is the third level of the OSI model
➢ Logical connection setup , data forwarding , routing and delivery
error reporting are the network layer's primary responsibilities
➢ It is considered the backboneof the OSI model . It selects and
manages the best logical path for data transfer between notes
➢ This layer contains hardware such as routers , bridges , firewalls and
switches
➢ It's protocol exist in every host
➢ Internet protocol and Netware IPX/SPX are the common protocols
associatedwith the network layer
➢ In OSI model it responds to requests from the layer above it (means
transport layer) and issues requests to the layer below it (means data
link layer)
Application​
Presentation​
Session​
Transport​
Network​
Data link​
Physical​

12. packetpacket
Network layer
Data DataTT2 TT2
From transport layer To transport layer
Network layer Network layer
To data link layer Form data link layer

13. Transport layer
➢ The transport layer is the fourth layer in OSI model responsible for end-to-
end communication over a network
➢ It is also responsible for the management of error correction , providing
quality and reliability to the end user
➢ It works transparently within the layers above to deliver and receive data
without errors . The send side breaks messages into segments and
passes them onto the network layer . The receiving side then reassembles
segments into messages and passes them to the application layer
➢ This layer can identify the symptoms of over loaded nodes and reduced
flow rates
➢ Service-point addressing , connection control , reassembly , flow
control , error control are the responsibilities of transport layer
➢ The common protocols that operate at this layer are TCP,UDP,SPX and
NetBEUI
Application​
Presentation​
Session​
Transport​
Network​
Data link​
Physical​

14. Transport layer
From session layer To session layer
H4 H4 H4H4 H4 H4
L5 data L5 data
Transport
layer
Transport
layer
L4 data
L4 data
L4 data L4 data
L4 data
L4 data
To network layer From network layer

15. Session layer
➢ The session layer is the fifth layer of OSI model which
controls the connection between multiple computers
➢ This layer tracks the dialogs between computers
called session
➢ This layer establishes , maintains and manage
connection
➢ It determines how two devices talk to each other
➢ It synchronizesuser tasks . It is responsible for
synchronizing information from different sources for
example , session are implemented in live television
programs
➢ Sessions are most commonly implemented using
protocols like Zone information , TheAppleTalk ..
these protocols also manage session through
checkpointing and recovery
Session
Application​
Presentation​
Session​
Transport​
Network​
Data link​
Physical​
Request
Response

16. Session layer
H5 Data Data Data H5 Data Data Data
Syn Syn Syn Syn Syn Syn
From presentation layer
To transport layer
To presentation layer
From transport layer
Session
layer
Session
layer

17. Presentation layer
Application​
Presentation​
Session​
Transport​
Network​
Data link​
Physical​
➢ It is layer 6 of the 7-layer OSI model
➢ It is use to present data to layer 7 in an
accurate , well-defined and standardized
format
➢ It concerned how data is converted and
formatted for data transfer
➢ This layer perform code conversion ,
data translation , compression and
encryption
➢ It is also called syntax layer
➢ The presentation layer is responsible for
graphic handling , character or string
conversion
HTTP etc..
Encrypt data
Decrypt data

18. Presentation layer
DataH6 DataH6
From application layer To application layer
To session layer From session layer
Presentation
layer
Presentation
layer

19. Application
Presentation
Session​
Transport​
Network​
Data link​
Physical​
Return content in
required format
Web browser
Application layer
Request content➢ It provides network services to user
application
➢ It is responsible for exchanging information
between programs running on the computer
➢ It is the only one layer that directly interacts
with the end user
➢ It provide services like file transfer , web chat
, Email clients , network data sharing , web
surfing , virtual terminals and data operations
➢ Error handling , recovery , data flow over a
network are the responsibilities of this layer
➢ More than 15 protocols are used in
application layer such as Telnet , file transfer
protocol

20. Application layer
Application
layer
Application
layer
User
Human or program
User
Human or program
H7 Data DataH7
To presentation layer From presentation layer
Message Message
X.500 FTAM FTAMX.500X.400 X.400