The OSI model is a framework for network communication comprising seven layers: physical, data link, network, transport, session, presentation, and application. It defines how data is transmitted across networks, utilizing protocols like TCP/IP, which facilitates data exchange over the internet. Although the OSI model is essential for understanding network structures, TCP/IP protocols are more widely used in practice.

1. PAPER NAME : COMPUTER NETWORKS
STAFF NAME : MISS.S.MANIMOZHI
CLASS : III BCA A
SEMESTER : VI
UNIT : I
TOPIC : OSI MODEL

2. OSI MODEL

3. Abstract
Introduction
OSI Model
Seven layers of OSI model
Protocol
TCP/IP
Physical layer
Data link layer
Network layer
Transport layer
Session layer
Presentation layer
Application layer
Conclusion

4. Introduction :
The Open System Interconnection orientation Model is a report for privileged
Infrastructure and computer network procedure & communication design.
It procedure data instant into seven layers which are the Application, Presentation,
Session, Transport,Network ,Data link and Physical layer .
It is therefore often refered to as the OSI Seven Layer duplicate.
OSI Model :
Open Systems Interconnection (OSI) is a set of globally recognized,
non-proprietary standards for network and for operating system occupied in
Networking functions.
It has seven layers.

5. Seven layers of OSI Model :
Physical layer
Data link layer
Network layer
Transport layer
Session layer
Presentation layer
Application layer
Protocol :
A protocol is a collection of rules and procedures for two computers
to exchange information
Protocol also defines the format of data that is being exchanged

6. TCP/IP is a set of procedure inhabited to allow cooperate computer
to split capital across a multipart.
TCP stand for “communication organize Protocol”
IP stands for “Internet Protocol”
They are Transport layer and Network layer protocols respectively of the
protocol suite
The mainly renowned system that adopt TCP/IP is Internet – the largest
WAN in the humanity
TCP / IP :

7. FTP, SMTP, Telnet, HTTP,…
TCP, UDP
IP, ARP, ICMP
Network Interface
TCP /IP LAYERS :

8. convert bits into electronic signals for outgoing messages
Converts electronic signal into bits for inward bound mail
This layer manage the boundary between the mainframe and the set of connections
medium (coax, twisted pair, etc.)
This place tells the driver software for the MAU (media addition unit,
ex. set of connections boundary cards (NICs, modems, etc.)) what needs to be sent corner to corne
the medium
The bottom layer of the OSI model
The physical layer is reliable for behavior of
Personality bits from one hop (node) to the next.
Layer 1 : Physical layer

9. Layer 2 :Datalink Layer
Handles individual information frames (packets) between the Network layer and
the Physical layer
At the receiving end, this layer correspondence raw data from the physical
layer into information frames for release to the Network layer
At the transport end this layer handle conversion of statistics into raw
Format that can be handle by the Physical Layer.

10. layer 3 : Network Layer
Handles address messages for delivery, as well as translating
logical network address and names into their physical counterpart
Dependable for decide how to route communication between computer
This layer also handles the decision needed to get data from
one point to the next location along a network path
This layer also finger packet switch and association congestion
control

11. Layer 4 : Transport layer
Manages the distribution of in sequence across a set of connections.
Manages the brook of information between parties by segmenting long statistics
Stream into smaller information chunks (based on allowed “packet” size
for a given transmission medium)
Reassembles chunks into their inventive sequence at the getting end
Provides acknowledgements of successful broadcast and
requests resends for packets which arrive with error.
The transport layer is accountable for the freedom.
of a message from one process to another.

12. Layer 5 : Session layer
Enables two set of connections wealth to hold constant infrastructure
(called a session) across a set of connections.
Applications on either end of the session are able to substitute facts for the period
of the assembly.
This layer is:
Responsible for initiating, maintaining and terminating sessions
Responsible for refuge and access control to assembly information
(via session applicant identification)
Responsible for synchronization services, and for checkpoint services

13. Layer 6 : Presentation layer
Manages data-format in sequence for networked connections
(the network’s translator)
For outgoing messages, it exchange data into a frequent format for set of connections
transmission; for incoming messages, it converts data from the generic complex
format to a layout that the receiving submission can recognize.
This layer is also accountable for certain procedure conversion, information
encryption/decryption, or information compression/decompression
A special software capacity called a “redirector” operates at this layer to conclude
if a petition is set-up related on not and forward network-related desires to
an proper network reserve .

14. Layer 7 : Application layer
The top coating of the OSI representation
provide a set of interface for transport and getting application and to use
network services, such as: memorandum handling and folder query meting out
Responsibility: The function layer is answerable for providing military
to the user.

15. Conclusion :
OSI Model are very practical ( except Session and presentation layers)
for discuss computer networks .but OSI protocols are not incredibly
popular.
TCP / IP Model is about unreal and on the contrary
TCP / IP protocols are very trendy.