A presentation briefly explaining about computer networks

1. A brief explanation about
networks

2. Network is a collection of
computer and other devices
like printers, scanners and so
on. The computers in a
network may be linked to other
devices through
cables, telephone lines, radio
waves, satellites etc.

3.  To share computer files.
 To share resources.
 To enable people to communicate.
 To reduce speed and cost of transfer.

4.  Personal Area Networks(PANs)
 Local Area Networks(LANs)
 Campus Area Networks(CANs)
 Metropolitan Area Networks(MANs)
 Wide Area Networks(WANs)

5. Pans
 Personal Area Network is an interconnection of
devices around an individual device within 5 to 10
meters.
 The devices that may be used in PANs are
computers, printers, fax machines, PDAs etc.

6. What are LANs?
 The terminals or workstations in a LAN are confined
to small areas such as a building or a group of
buildings.
 It may be up to a kilometer.
 For example, department of an office.

7. A CAN covers a group of buildings like college
campus or office campus.
 It is basically a collection of LANs in various
buildings.

8. What are MANs?
 The MANs lies between LANs and WANs.
 MANs connect two or more local area networks or
campus area networks together and is spread over a
town or city.
 It does not exceed 10 kilometers.
 For example, MAN connects the local bank with all
the branches in the city.

9. What are WANs?
 WANs spans a large area-a country or
many countries or a continent.
 A WAN may connect a number of
LANs, CANs, or MANs located in any
part of world.
 Example, WAN is the internet which is
the most popular and the largest WAN.

10. WIDE AREA NETWORK

11.  It is the geometric layout of computers and
other devices. The types of topologies are:-
 Linear bus topology
 Ring topology
 Star topology.

12. What is Linear Bus Topology?
 It has a common backbone cable to
which all the nodes and peripheral
devices are attached.
 All the devices are attached to this
backbone cable.
 The disadvantage of the linear bus
topology is that if the backbone cable
fails, then the network becomes
useless.

13. Linear Bus Topology

14.  It connects the nodes of the network in a
circular chain.
 The final node in the chain connects to
the first to complete the ring.
 A computer has two adjacent
neighbors.
 The main disadvantage is that if one
cable is broken, the whole network
becomes useless.

16.  There is a central switch to which all the
nodes are directly connected.
 Every node is indirectly connected to
another node through the central hub.
 The failure of any node does not cause
the breakdown of the network.
 The disadvantage is that if the central hub
will cause a breakdown, the network is
broken.
Star topology

17. Star topology