2. WE WILL LEARN ABOUT
Definition of Computer Network & its
examples
Advantages of Networking
Networking Components
Types of Networks
Network Architecture
Network Topologies
NetworkSecurity
3. DEFINTIONS & EXAMPLES OF
COMPUTER NETWORK
DEFINTIONS:
A computer network isdefined asthe interconnection
of two or more computers. It isdone to enable the
computers to communicate and share available
resources.
A computer network enables two or more computers
to share data and peripheral devices. They communicate
with each other, as well as work independently.
4. EXAMPLES:
i. Network of roads ,railway lines , canals,etc.
ii. Communication network of telephone system which enable us to talk to
anyone , anywhere & anytime .
iii. Network of Banks/ATMs(Automated Teller Machines).
iv. Radio /Television network broadcasts programs live across the globe.
v. A network of malls , schools & hospitals , etc all over the country.
5. ADVANTAGES OF NETWORKING
FileSharing:Networksoffera quickandeasy
waytosharea filedirectly.
Resource Sharing:All computers in the
network can share resources such as
printers, fax machines, modem and scanners.
Communication: Those on the network
can communicate with each other via e-
mails,instant messages,etc.
FlexibleAccess:Networksallowstheirusersto
accessfilesfromcomputersthroughoutthe
network.
6. ADVANTAGES OF NETWORKING
Sharing of Information: Computer networks
enables us to share data and information with
the computers that are located geographically
large distance apart.
7. NETWORKING COMPONENTS
NetworkCard:ANetwork interface card (also
known as a NIC, network card, or network
interface controller) is an electronic device
that connects a computer to a computer
network. It is considered a piece of computer
hardware. Nowadays, most computer
motherboards come with an inbuilt Network
Card.
8. NETWORKING COMPONENTS
NetworkingCable:Networking cables are networking
hardware used to connect one network device to other
network devices or to connect two or more computers
to share printers, scanners etc. Different types of
network cables, such as coaxial cable, optical fiber
cable, and twisted pair cables, are used depending on
the network's physical layer, topology, and size.
9. NETWORKING COMPONENTS
Modem:A modem is a hardware device that converts
data from a digital format, intended for communication
directly between devices with specialized wiring, into
one suitable for a transmission medium such as
telephone lines or radio.It converts the digital signals of
a computer into analog signals to enable their
transmission via phone lines.
10. NETWORKING COMPONENTS
Hubs&Switches:A network switch (also
called switching hub and bridging hub) is networking
hardware that connects devices on a computer
network by using packet switching to receive and
forward data to the destination device.
12. LOCAL AREA NETWORK(LAN)
LAN isa network whichisdesigned to operate over
a small physical area suchasan office, factory or a
group of buildings.
LAN’s are easyto designand troubleshoot
Exchange of information and sharing of resources
becomeseasybecauseof LAN.
In LAN all machinesare connectedto a single
cable.
Different types of topologiessuchasstar, tree, bus,
ring, etc Can be used.
13. METROPOLITAN AREA NETWORK(MAN)
It isin between LAN & WAN technology that covers
the entire city.
It usessimilar technology asLAN.
It can be a singlenetwork suchascable TV network,
or a measure of connectinga
number of LAN’soa large network sothat resourcescan
be shared LAN to LAN aswell as device to device.
14. WIDE AREANETWORK(WAN)
When network spansover a large distance or when the
computers to be connectedto each other are at widely
separated locationsa local area network cannot be
used.A wide area network(WAN) isinstalled.
Thecommunication between different usersof WAN
isestablished usingleased telephone lines, satellite
links and similar channels.
It ischeaper and more efficient to usethe phone
network for the link.
15. PERSONALAREA NETWORK(PAN)
A personal area network isa computer network organized
around an individualperson.
It generally consistsof a mobile computer, a cell phoneor
personal digital assistant. PAN enables the communication
among these devices.
It can alsobe usedfor communication among personal devices
themselves for connecting to a digital level network and
internet.ThePANs can be constructedusingwirelessor cables.
17. PEERTO PEER NETWORK
In peer to peer network each computer is
responsible for making its own resources
available to other computers onthe network.
Eachcomputer isresponsible for setting up and
maintaining its own security for these
resources.
Alsoeach computer isresponsible for accessing
the required network resourcesfrom peer to
peer relationships.
Peer to peer network isuseful for a small
networkcontaining lessthan 10computers on a
single LAN .
In peer to peer network each computer can
function asboth client and server.
Peer to peer networks do not have a central
control system.
There are no serversin peer networks.
18. ADVANTAGES & DISADVANTAGES
OF PEERTO PEER NETWORK
Not very secure
No central point of
storage or file archiving
Additional load on
computer becauseof
resource sharing
Hard to maintain
version control
Advantages:
Useless expensive
computer hardware
Easyto administer
No NOS required
More built in
redundancy
Easysetup & low cost
Disadvantages:
19. CLIENT/SERVERNETWORK
In client-server network relationships, certain
computers act asserverand other act as
clients.A server issimply a computer, that
available the network resourcesand provides
serviceto other computers when they request
it. A client is the computer running a
program that requeststhe service from a
server.
Local area network(LAN) isbased on
client server network relationship.
A client-server network isone n which all
available network resourcessuchasfiles,
directories, applications and shared
devices, are centrally managed and hosted
and then are accessedbyclient.
Client servenetwork are defined by the
presence of serverson a network that provide
security and administration of the network.
20. Advantages:
Very secure
Better performance
Centralized backup
very reliable
Disadvantages:
requires professional
administration
More hardware-
intensive
More software
intensive
Expensivededicated
software
ADVANTAGES & DISADVANTAES
OF CLIENT-SERVER NETWORK
21. NETWORK TOPOLOGIES
Network topology is the way a network is arranged,
including the physical or logical description of how
links and nodes are set up to relate to each other.
22. POINT TO POINT TOPOLOGY
In a point-to-point connection, a communication link is
established between two devices with one wire or air (in the
case of wireless). A simple example of point-to- point
connection is talking over telephone between two persons
where anyone else is not allowed to use the phone on
either side.
23. BUS TOPOLOGY
In a bus network, a common backbone is connected to all network
devices. The high capacity bus backbone (generally a single cable)
functions as a shared communications medium and it joins networks
and central devices. If any network device wants to communicate with
another network device within a bus network, the device sends a
broadcast message onto the backbone. All other devices will see the
broadcast message but only the desired recipient will accepts and
process the message.
24. STAR TOPOLOGY
Star topology is the most popular network topology that is used in many
business and home networks today. A star topology is established with a
central connection point called a hub node. The hub may be an actual
hub device or a network switch or a network router.The main benefit of a
star network is that failure in any start network cable will only take down
one computer’s network access but not the entire LAN. However, if the
hub node fails, the entire network will be down in a start network.
25. RING TOPOLOGY
In a ring network, every network device is connected to two neighbor
devices with a point-to-point connection for communication purpose. All
devices in a ring network make a loop. If any cable or device is fail, the
loop will break and also break down the entire ring network. In the ring
network, messages travel through the loop in the same direction
(effectively either clockwise or counterclockwise).
26. TREE TOPOLOGY
The tree topology is also known as hierarchical topology. In a tree
topology, a central ‘root’ node (top level of the hierarchy) is connected to
one or more other nodes that are one level lower in the hierarchy with a
point-to-point physical link. The second level node may also have
connected to one or more other nodes that are one level down in the
hierarchy with another point-to-point link. The top level node i.e root node
is the only node that has no other node above it in the hierarchy.
27. MESH TOPOLOGY
In a mesh network, every network device is connected to every other
network device with a point-to-point connection. This topology is mostly
used in WAN and wireless networks. The route concept is introduced by
mesh topology and this topology is used by routers to determine the best
path.As each device is connected to all other devices in a mesh network,
this topology is the most expensive and difficult to maintain.
28. NETWORK SECURITY
Network security consists of the policies and practices adopted to
prevent and monitor unauthorized access, misuse, modification, or
denial of a computer network and network-accessible resources.
Network security involves the authorization of access to data in a
network, which is controlled by the network administrator. Users
choose or are assigned an ID and password or other authenticating
information that allows them access to information and programs
within their authority.
Network security covers a variety of computer networks, both public
and private, that are used in everyday jobs: conducting transactions
and communications among businesses, government agencies and
individuals.
29. NETWORK SECURITY
Networks can be private, such as within a company, and others
which might be open to public access.
Network security is involved in organizations, enterprises, and other
types of institutions. It does as its title explains: it secures the
network, as well as protecting and overseeing operations being
done. The most common and simple way of protecting a network
resource is by assigning it a unique name and a corresponding
password.
