you will come to know abot open system interrconnection and its seven layers.

1. PRESENTATION
ON
OSI MODEL
BY- BHUMIKA VATS

2. DEFINITION OF OSI MODEL
OSI stands for Open System Interconnection is
a reference model that describes how informa-
tion from a software application in one computer
moves through a physical medium to the soft-
ware application in another computer.

3. OBJECTIVES OF OSI MODEL
1) To provide a set of design standards for equipment
manufacturers so they could communicate with each
other.
2)The purpose of the OSI reference model is to guide
vendors and developers so the digital communi -
cation products and software programs they create
can interoperate, and to facilitate a clear framework
that describes the functions of a networking or
telecommunication system.

6. APPLICATION LAYER
An application layer is an abstraction layer that
specifies the shared communications protocols and
interface methods used by hosts in a communications
network. The application layer in the OSI model is the
closest layer to the end user which means that the
application layer and end user can interact directly with
the software application. The application layer
programs are based on client and servers.

7. PRESENTATION LAYER
The primary goal of this layer is to take care of
the syntax and semantics of the information
exchanged between two communicating systems.
Presentation layer takes care that the data is sent in
such a way that the receiver will understand the
information(data) and will be able to use the data.
Languages(syntax) can be different of the two
communicating systems. Under this condition
presentation layer plays a role translator.

8. SESSION LAYER
The Session Layer allows users on different machines to
establish active communication sessions between them.
It's main aim is to establish, maintain and synchronize
the interaction between communicating systems.
Session layer manages and synchronize the
conversation between two different applications. In
Session layer, streams of data are marked and are
resynchronized properly, so that the ends of the
messages are not cut prematurely and data loss is
avoided.

9. TRANSPORT LAYER
The transport layer is the layer in the open
system interconnection (OSI) model responsible
for end-to-end communication over a network. It
provides logical communication between
application processes running on different hosts
within a layered architecture of protocols and
other network components.

10. NETWORK LAYER
The network layer is the third level of the Open
Systems Interconnection Model (OSI Model) and
the layer that provides data routing paths for
network communication. Data is transferred in
the form of packets via logical network paths in
an ordered format controlled by the network
layer.

11. DATALINK LAYER
• In the OSI model, the data link layer is a 4th layer from the top
and 2nd layer from the bottom.
• The communication channel that connects the adjacent nodes
is known as links, and in order to move the datagram from
source to the destination, the datagram must be moved
across an individual link.
• The main responsibility of the Data Link Layer is to transfer
the datagram across an individual link.
• The Data link layer protocol defines the format of the packet
exchanged across the nodes as well as the actions such as
Error detection, retransmission, flow control, and random
access.

12. PHYSICAL LAYER
The physical layer is the first layer of the Open System
Interconnection Model (OSI Model). The physical layer
deals with bit-level transmission between different
devices and supports electrical or mechanical interfaces
connecting to the physical medium for synchronized
communication.

14. Thank you