Download Networks

Chapter 3

The characteristics of:
◦ Local Area Networks
◦ Wide Area Networks
◦ Virtual Networks


A network is
are connected together.
computers which
By connecting computers together, they are
able to talk to each other and
like files and hardware (printers,
scanners etc).


Computers which are
.
You usually find them in:
◦
◦
◦
◦
◦
◦
Schools
Libraries
Doctor and Dentist surgeries
Hospitals
Police Stations
And increasingly more at home.


Computers are connected in a local
geographical location.
Workstations have either physical or wireless
network connections.

Peripherals are often shared.

Software and data can be shared.




Increasingly, more and more
households how have more than one
computer or laptop.
Data is now being shared across
these devices including music and
video streaming.
Printers are shared across the
network also.
Media can also be streamed to
devices like Xbox 360 and PS3
consoles.
◦ This allows people to stream music from
their PC and play it through their console
while playing a game!
Switch
Wireless Access Point
(WAP)

Computers are connected across a wider area
compared to LAN.
◦ The geographical locations are far apart.


The internet is a fantastic example of a WAN.
Computers are able to connect to one
another through the internet.

Some systems might need WAN connections
as well as LAN connections.

Examples include:
◦ University campuses spread over large areas
◦ The medical network (allows medical records to be
accessed from all over the country)
◦ ATM machines
◦ Large global businesses


Computers are not close together.
External equipment may be needed to
connect computers together:
◦ Telephone lines
◦ Satellite
◦ Mobile Phones

Specialist equipment is needed to connect to
the WAN e.g. Router or modem.
Router
Is a WAN network...
But is made up of lots of single computers and LAN networks.
LAN 2
LAN 1


There may be many computers connected in
a LAN but they can be fooled into thinking
that their network is much smaller.
This is accomplished by using virtual
networks to limit what computers another
computer can see on the network.
The computers
surrounded with
red do not know the
blue computers
exist.
The switch ‘hides’
the blue computers
from the red
computers.
This example shows how
computers might be
connected using a virtual
network across a WAN.
The red computers
communicate with each
other and are unaware of the
blue computers.

Identify three characteristics of a LAN

Identify two characteristics of a WAN

Describe the purpose of a Virtual Network

Identify four services offered by an ISP