This is based on the networking.

2. INTRODUCTION :
Definition :
A computer network is a set of computers connected
together for the purpose of sharing resources. The most
common resource shared today is connection to the Internet.
Other shared resources can include a printer or a file server.

3. Types of computer network topologies
Bus Topology Star Topology
Mesh Topology
Tree Topology
In this bus topology, every workstation is connected to a main cable
called the bus. Therefore, in effect, each workstation is directly
connected to every other workstation in the network.
Bus Topology
Ring Topology

4. Star Topology
Advantages :
Easy to install and configure Inexpensive
Disadvantages :
Weak signals Performance decreases
In this star topology, there is a central computer or server to
which all the workstations are directly connected. Every
workstation is indirectly connected to every other through the
central computer.
Applications :
Most computer motherboard

5. Advantages :
Each device requires own cable segment
If the central hub fails, the whole network fails to
operate
Disadvantages :
Easy to add and modify the new nodes
Ring Topology
In this ring topology each computer is connected to the
next computer with last one connected to the first one.
Applications :
Local Area Networks(LANs) High speed LAN often used star

6. Advantages :
Easy to install Fault identification is easy
Disadvantages :
Break in a single ring can break whole network
Applications :
Today high speed LANs made this topology less popular
Mesh Topology
A mesh topology is a network topology in which all the network nodes are
individually connected to most of the other nodes

7. Advantages :
Provides security and privacy It is robust
Disadvantages :
Maintenance is very difficult
Applications :
It can be applied both wired and wireless networks
Tree Topology
Tree topology combines the characteristics of two topologies both bus topology
and star topology .

8. Advantages :
Supported by several hardware and software vendors
Disadvantages :
More difficult to configure
Hybrid Topology
A hybrid topology is a type of network topology that uses two or more other
network topologies, including bus topology, mesh topology, ring topology, star
topology, and tree topology.

9. Advantages :
Reliable Flexible
Disadvantages :
Costly hub Costly infrastructure
OPEN SYSTEM INTERCONNECTION (OSI MODEL)
The Open Systems Interconnection model (OSI model) is a conceptual model
that characterizes and standardizes the communication functions of a
telecommunication or computing system without regard to their underlying
internal structure and technology. International standards organization (ISO)
developed by OSI model .
Physical Layer Session Layer
Data link Layer Presentation Layer
Network Layer Application Layer
Transport Layer

13. Physical Layer
One of the major function of the physical layer is move data in the form of
electromagnetic signals across a transmission medium
Both data and the signals either analog and digital
Functions :
Physical characteristics of interface and medium
Representation of bits Data rate
Synchronization of bits Line configuration
Physical topology Transmission mode

14. Data link Layer (Host to Host) :
Data link layer is responsible for the moving frames from one node to next
node
Functions :
Framing Physical addressing
Flow control Error control
Access control

15. Network Layer (Source to Destination) :
The network layer is responsible for the delivery of individual packets from
the source host to the destination host
Functions :
Logical addressing
Routing

16. Transport Layer (Process to Process) :
The transport layer responsible for the delivery of a message from one
process to another process
Functions :
Service- point addressing Segmentation and reassembly
Connection control Error control
Flow control

17. Session Layer (dialog initiation) :
The session control is responsible for the dialog control and
synchronization
Functions :
Dialog control
Synchronization

18. Presentation Layer (Dependency) :
The presentation layer is responsible for the translation, compression,
encryption
Functions :
Translation
Compression
Encryption

19. Application Layer (User Level Service) :
The application layer is responsible for providing services to the user
Functions :
File transfer, access and management
Mail services

20. THANK YOU
NAVEENA.D