This presentation provides an overview of computer networks. It defines what a network is and discusses the main types: human networks and computer networks. It then covers the key aspects of computer networks including definitions of LANs, MANs, and WANs. The presentation outlines the basic components of a computer network, including hubs, switches, bridges, routers, repeaters, and gateways. It also discusses network topologies, media types, and the advantages and disadvantages of computer networks.

1. This Presentation is presented by:
 Vaibhav Gadhave
 Shubham Chavan
 Karthik A.K.
 Suraj Soni
 Sudarshan Suryavanshi
 Swapnil Shedge
On the topic Computer Network

2. What do you mean by a NETWORK ?
You probably hear the term “Network"
tossed around a lot. But have you ever wondered
exactly what a Network is.

3. Definition :-
Network is a broad term similar to “system”. Network is a
communication system which supports many users.
The interconnection of one station to many station is called as
networking.
A network is any interconnection of tow or more stations that
wish to communicate.
Each station in a communication network is called a node. The
node are connected in different way to each other to form a
network.

4. TYPES :-
Human Network :- Human network is a network that connects
two or more human beings and bring them to a network so
they share there thoughts, knowledge, things etc. with each
other.
Computer Network :- A computer network is defined as the
interconnection of two or more computer. It is done to enable
the computers to communicate and share the available
resources.

5. Something's more about COMPUTER
NETWORK.
A computer network is a group of interconnected computers.
It allows computers to communicate with each other and to
share resources and information.
First Network : The Advanced Research Projects Agency
(ARPA) funded the design of the "Advanced Research Projects
Agency Network" (ARPANET) for the United States
Department of Defense

6. Types of Network
LAN :- Local Area Network
MAN :- Metropolitan Area Network
WAN :- Wide Area Networks

7. Local Area Network (LAN)
Local area network is a network which is designed to operate over a small
physical area such as an office, factory or a group of building. LANs are
very widely used in a variety of applications.
LANs are easy to design and troubleshoot. The personal computer and
workstation in the offices are interconnected via LAN.
The exchange of information and sharing of resource's becomes easy
because of LAN.
In LAN all the machines are connected o a single cable. Different type of
topologies are used for LANs.
LANs uses a layered architecture and they are capable of operating at
hundreds of Mbits/sec.
A LAN is usually a privately owned and links the devices in a single office,
building or campus of up to a few kilometers in size.

8. Metropolitan Area Network
(MAN)A MAN is basically a bigger version of a LAN and normally uses similar
technology. It is designed to extend over an entire city.
It can be single network such as a cable TV network, or it be a mean of
connecting a number of LANs into a large network so that resources can
be shared LAN to LAN as well as device to device.
A MAN may be wholly owned and operated by a private company or it
may be a service provided by a public company, such as a local telephone
company (Telco).
The speed of the MAN is too slow as compare to the LAN

9. Wide Area Networks
(WAN)

10. Difference Between the types of
Computer network
PARAMETERS LAN WAN MAN
Ownership of network Private Private or public Private or public
Geographical area
covered
Small Very large Moderate
Design and maintenance Easy Not easy Not easy
Communication medium Coaxial cable PSTN or satellite links
Coaxial cables, PSTN,
optical fibre, cables,
wireless
Bandwidth Low High moderate
Data rates(speed) High Low moderate

11. Network component Devices
Hub
Switch
 Bridges
Routers
Repeaters
 Gateways

12. HUB
S
Hubs are devices used to link several computers together. They repeat any signal
that comes in on one port and copy it to the other ports (a process that is also
called broadcasting).
There are two types of hubs: active and passive.
Passive hubs simply connect all ports together electrically and are usually not
powered.
Active hubs use electronics to amplify and clean up the signal before it is
broadcast to the other ports.
In the category of active hubs, there is also a class called “intelligent” hubs, which
are hubs that can be remotely managed on the network.

13. A network switch is a computer networking device that connects network segments.
Low-end network switches appear nearly identical to network hubs, but a switch contains
more "intelligence" (and a slightly higher price tag) than a network hub.
Network switches are capable of inspecting data packets as they are received, determining
the source and destination device of that packet, and forwarding it appropriately.
By delivering each message only to the connected device it was intended for, a network
switch conserves network bandwidth and offers generally better performance than a hub.
A vital difference between a hub and a switch is that all the nodes connected to a hub share
the bandwidth among themselves, while a device connected to a switch port has the full
bandwidth all to itself.
For example, if 10 nodes are communicating using a hub on a 10-Mbps network, then each
node may only get a portion of the 10 Mbps if other nodes on the hub want to
communicate as well. But with a switch, each node could possibly communicate at the full
10 Mbps.
Switch

14. Bridges
They join similar topologies and are used to divide network segments.
For example, with 200 people on one Ethernet segment, the performance will
be mediocre, because of the design of Ethernet and the number of workstations
that are fighting to transmit. If you divide the segment into two segments of 100
workstations each, the traffic will be much lower on either side and
performance will increase.
If it is aware of the destination address, it is able to forward packets; otherwise a
bridge will forward the packets to all segments. They are more intelligent than
repeaters but are unable to move data across multiple networks simultaneously.
Unlike repeaters, bridges can filter out noise.
The main disadvantage to bridges is that they can’t connect dissimilar network
types or perform intelligent path selection. For that function, you would need a
router.

15. Routers
Routers are highly intelligent devices that connect multiple network types and
determine the best path for sending data.
The advantage of using a router over a bridge is that routers can determine the
best path that data can take to get to its destination.
Like bridges, they can segment large networks and can filter out noise.
However, they are slower than bridges because they are more intelligent devices;
as such, they analyze every packet, causing packet-forwarding delays. Because of
this intelligence, they are also more expensive.
Routers are normally used to connect one LAN to another. Typically, when a WAN
is set up, there will be at least two routers used.
Internetwork connectivity device

16. Repeaters
Repeaters are very simple devices. They allow a cabling system to extend beyond
its maximum allowed length by amplifying the network voltages so they travel
farther.
Repeaters are nothing more than amplifiers and, as such, are very inexpensive.
Repeaters can only be used to regenerate signals between similar network
segments.
For example, we can extend an Ethernet 10Base2 network to 400 meters with a
repeater. But can’t connect an Ethernet and Token Ring network together with one.
The main disadvantage to repeaters is that they just amplify signals. These signals
not only include the network signals, but any noise on the wire as well.
Operates at the physical layer of the OSI model

17. Gateways
A gateway is a network point that acts as an entrance to another
network. On the internet, in terms of routing, the network
consists of gateway nodes and host nodes.
Host nodes are computer of network users and the computers
that serve contents (such as Web pages).
Gateway nodes are computers that control traffic within your
company’s network or at your local internet service provider
(ISP)
Internetwork connectivity device

19. Classification Of Media Type
BOUNDED MEDIA :-
 Twisted pair
 Co-axial cable
 Fiber optic
UNBOUNDED MEDIA :-
 Microwave
 infrared
We will concentrate on Bounded media
here.

20. TWISTED PAIR
Twisted pair cabling is a type of wiring in which two conductors of a
single circuit are twisted together for the purposes of canceling
out electromagnetic interference (EMI) from external sources; for
instance, electromagnetic radiation Least expensive and widely used
Consists of two copper wires arranged in regular spiral pattern.
Can transmit both analog and digital.
Most commonly used medium in telephone network.
Two types:
UNSHIELDED TWISTED PAIR (UTP) CABLE.
SHIELDED TWISTED PAIR (STP) CABLE.

21. UNSHIELDED TWISTED PAIR
CABLE
Set of twisted pairs of cable within a plastic sheet
Transmission rate of 10-100Mbps
Least expensive
Maximum cable segment is 100meters
Very flexible and easy to work
Uses RJ-45 connector
Most susceptible to electrical inference or cross talk
MetalInsulator

22. SHIELDED TWISTED PAIR CABLE
STP cables are similar to UTP cables, except there is a metal
foil or braided-metal-mesh cover that encases each pair of
insulated wires
It offers protective sheathing around the copper wire.
Provides better performance at lower data rates.
Not commonly used
Installation is easy
Distance is only 100-500 meters
Special connecters are required.
Also suffers from outside interference

23. Coaxial cable, or coax is a type of cable that has
an inner conductor surrounded by a tubular
insulating layer, surrounded by a tubular
conducting shield. Many coaxial cables also have
an insulating outer sheath or jacket.
Co-axial cable

24. OPTIC FIBRE CABLE
It is a light pipe which is used to carry a light beam from
one place to another.
How optical fibers work?
They may be single, but often they are bundled
together in center of cable
They are either single mode or multimode.
Multimode use multiple light paths whereas single
mode use single light path

25. Network Topology
The network topology defines the way in which computers,
printers, and other devices are connected. A network topology
describes the layout of the wire and devices as well as the paths
used by data transmissions.
Types of topology:-
 Bus Topology
 Star Topology
 Ring Topology

26. Bus Topology
• Network wherein all devices connect to a
single cable. If the cable fails, the network
is down.

27. Star Topology
Most common Ethernet network topology where
each device connects to a central hub or switch.
When installed, the star topology resembles spokes
in a bicycle wheel.

28. Network that is physically wired like a star network
but, logically in a ring; passes control from one device
to the next in a continuous fashion using a special data
packet called a token. Used in Token Ring networks
Ring Topology

29. Advantage of Computer
networks
Sharing of Devices such as printer and scanner
Sharing program / software
Sharing files
Sharing data
Sharing information
Sharing of single high-speed internet connection
Better communication using internet services
such as email, mailing list and internet Relate
chat (IRC).

30. Disadvantage of Computer Network
× The larger network becomes, the more difficult it is
to manage.
× If the network stops operating system, then it may
not be possible to access various resources
× Computer Viruses: If any computer system in a
network gets affected by computer virus, there is a
possible threat of other systems getting affected too.