Chapter 4 ICT

1. Networks
A network is two or more computer that are linked together for sharing the
same resources. The resources may be printer , scanner and the internet.
Network devices
To establish the networking some network devices are needed.
Router
Each computer linked to the internet have a unique IP address (internet protocol
) . An IP address looks like the : 123.456.1.98.
When data is send from one network to another , its goes in the packets.
Each packet have the details of the destination address of the network .
Computer on the same network all have the same first part of the IP address.
Routers are the devices that read the address information to determine the final
destination of the packet , via the stored information router direct the packet to
the next network journey.

2. Router
Then data packet is received by the other router to send to final destination.
Router can be used to connect to join several wireless networks or wired
network together.
Routers behaves like an gateways so that computer network can be
communicate together.

3. Network interface cards (NIC)
Before computer connect to network it must have the NIC . In most of modern
computers NIC is in build in the computers.
These card directly going to connect to mother board and outer socket used to
connect to a network via cables.
NIC does the following :
 It prepares the data for sending
It control the flow of data from computer to the transmission media.

4. Hubs
It is simply used to enable computer to share files and hardware's like scanner and
printers.
We know that data flow into the packets on the network . A hub contains multiple
ports . When a packet arrives at one port it is transferred to another port so that
all networks computer can see all the packets.
Every device on the network will receive the packet of data.

5. Switches
Its work same as hub but work in the smart way . Switches read the packet of
data and send on the correct computers.
Because it only sends the data to the correct computer so it reduce the traffic on
the network ; thus speed up the network.

6. Bridges
Bridges are used to connect to LAN together . When one of the LAN send the
message on the network then all LAN devices receives the message.
LAN is divided into a series of smaller LAN’s. If a message pass from one
computer in LAN to different LAN then the message needs to pass between the
LAN using a bridge.
The advantage is subdividing a larger network is that reduces the traffic with a
different LAN.
A bridge therefore have only two ports in order to connect one LAN to another
one.

7. Modems
Modems are largely replaced by the routers cause of faster access of the internet.
A modem converts the data from the computer into sound that can be send along
ordinary telephone lines.
Once the data is received at another end then sound need to convert it back to
digital data using another modem.

8. The use of Wi-Fi and Bluetooth in networks
There are two main technologies that allow wireless communication between
computers.
Wi-Fi
Wi-Fi enables the devices to communicate with each other wirelessly . Areas
where the internet can access wirelessly using Wi-Fi known as access point or hot
spot , it can be find out in public places such as -: airports , coffee shops.
The range of the Wi-Fi depends on the type of wireless router being used , if
there are obstacles like as wall then the speed will going to minimum. The range
is 50 m inside and 100m outside.

9. The use of Wi-Fi and Bluetooth in networks
Advantage of wireless communication:
You can work wirelessly anywhere.
You can work in any environment like in trains , buses and in some air flights.
It is easier to keep area clean cause no wires.
No network wires so that the cost of installation is so low.
Disadvantage of wireless communication:
The danger of hackers.
There are some areas where you cannot get wireless network.
There are some evidence that there may be danger to health.

10. Bluetooth
Bluetooth is a wireless technology used for send the data in between short
distance range , its depend on power of signals.
Typically range is around 5m – 100 m .
Use of Bluetooth:
If you have wireless keyboard and mouse then they could use Bluetooth ,
printers also can be controlled via Bluetooth.
Communication between a wireless hands-free headset and a mobile phone.
We can create a small wireless network where computers are so near and low
bandwidth is not an problem.
Transferring small amount of the data like -: appointments , contacts details
between devices.
In many games its used Bluetooth consoles.

11. Setting and configuring a small network
For setting up small network , it can be done in following easy steps - :
1. Choose an ISP and then pay them for subscription charges and for the router
(Which have wireless access point).
2. Connect to the router to the telephone lines or cable point.
3. Connect any cabled device to the router using wires between the ports of the
routers and the NIC on the device.
4. Connect wireless device like -: laptop , printer using wireless network . You
will need to open the setting in your O.S and then set a new connection for
each device.
5. You will need a browser for access the internet for each device.

12. Web browser s/w
A web browser is an s/w that allow you to website pages or internet on your
devices.
Web browser read the instruction that how to display the web page on devices .
That instruction are made from HTML ( Hyper text markup language).
Web browser allow to user to find out certain information in these steps - :
1. Entering a URL (Universal resource locator).
2. A web / internet portal
3. Keyword searches
4. Links
5. Menus

13. Access to ISP
Connecting directly to the internet is really very expensive that is suitable for big companies.
Most of peoples are taking the internet services from the ISP .
These ISP provides you to access the internet as well as some other services -:
Storage on their server , where you can store your website.
E-mail facility
Instant or short messages
Access to news , weather, finance , games pages etc.
When you establish a network with the ISP , they generally supply you the wireless routers .
This will allow you to link devices wirelessly by that you can share the resources like - : printers
and other hardware devices.
****At the back of the router you can see some sockets where you can place Ethernet cable
can be connected.

14. The internet
The internet is a huge group of worldwide network making communication which
other.
When you connect to the internet it means you become a small part of this big
network.
Advantage of the Internet:
Huge amount of info can be access from anywhere and on anytime
Improved communication system - : IM,E-mails , Chatting
Online shopping/online banking
VOIP(Voice over internet protocol) -:By that we can make cheap call sending our
voice data over the internet , without paying to the long bills on the mobiles
phones example : Skype , We chat , viber.
Disable peoples can shop online.

15. The internet
Disadvantage of the Internet:
There are so many bogus or fake information reside on the internet . So we
have to careful before going to relay on that.
Cyber crime on internet are now very common on internet , so we have to be
careful to share our personal information.
There are so many gambling websites.
Hacking and virus problems

16. E-commerce
Sometime organization publish their website for promotional purpose or some
time for selling their good , this is known as E-commerce.
On these websites buyer can see the different products and then can add on their
virtual shopping basket.
After they have to do the payment for their purchasing via card or online banking
method.
They have to fill there contact details for delivery of the product at their door.

17. The difference between Internet and WWW
The internet is a huge networks of the small network that going to
communicate with each other.
The WWW is the way of accessing all that information on all these networked
computers.

18. Intranets
AN intranet is an private network , that is used by the same organization peoples
in one campus.
Schools are using the intranet for keep the details of teachers record , student
records , time table and other things.
Parts of an intranet can be available to anyone in the organization , but some
personal details are only accessed by certain peoples.
Restriction of the certain part for others is done by allotting the user their unique
ID and password.

19. The difference between Intranet and internet
Intranet Internet
Intranet stands for Internal restrict access
network
Internet stands for INTER national network
It contains information about certain
organization.
Internet contains information about
everything.
Intranet can be used by some employees of
the organization.
Internet can be used by everyone.
In intranet we can block the websites via using
proxy server.
Via a internet can be accessed any website.

20. Intranet
Advantages of intranet -:
Intranets are ideal to use in schools for preventing the certain website or
unwanted information.
The internal mail system is more secure then using the internet.
Only that information is accessible to the users that is don’t going to waste
their time.

21. Two types of network LAN and WAN
LAN WAN
LAN stands for local area network WAN stands for wide area network
Covers small area ( one site or in a one
building)
Cover large geographical area (countries ,
different building , cities )
Use cables , wireless , infra red owned by
organization
Expensive equipment's supplied by companies
(satellite links)
Less expensive More expensive

22. WLAN
Wireless local area network where the computers can communicate via wirelessly
in on building example : in one home all the peoples can access the internet.
Advantage of WLAN over cabled LAN - :
Cheaper cause less cabling is needed.
It is easy to link the devices such as printer and scanners.
In the range of wireless you can work anywhere.
Disadvantage of WLAN over cabled LAN - :
In some area of building the signals may be low.
Signals may be hacked by the hackers.
Wireless signals are not reliable , cause data transfer rate may be not so high.
Electronic equipment can be cause of the disturbance of signals.

23. Advantage and disadvantage of using different devices to
access the internet
We can access the internet from different devices , each devices have their advantage
and disadvantages.
Internet access through smartphone
Advantage - :
Internet can be accessed anywhere even from Wi-Fi and mobile signals.
Stay connected while you are walking
Disadvantage - :
It is possible that children's could access the unsuitable content ,cause its not easy to
monitor.
Some website have trimmed version for the smartphones.
Small screen and keyboard is frustrating.
It will be with you every time , so you are checking mails and other stuff , so you are
missing social life.

24. Advantage and disadvantage of using different devices to
access the internet
Internet access through tablet
Advantage - :
Tablets are lightweight , easy to carry.
Tablets have larger screen in compare to smartphone so easy to work.
Disadvantage - :
Tablets have smaller screen in comparison to desktop and laptop computers.
Tablets comes with virtual keyboard which is not easy to work.
It can cause health problems cause of awkward positions.

25. Advantage and disadvantage of using different devices to
access the internet
Internet access through Laptop computer
Advantage - :
Smaller and lighter in comparison to desktop ( portable ) .
Have a large screen in comparison to tablet and smart phones , so easy to work.
Have keyboard so its makes easy for typing large amount of the data.
Can be used when flat surface is not there.
Disadvantage - :
Not portable in comparison to tablet and smart phone.
Screen and keyboard are attached so it may caused of health problem in longer run.

26. Advantage and disadvantage of using different devices to
access the internet
Internet access through Desktop computer
Advantage - :
Full size key board makes it easy for typing large data.
Most of the websites are designed to be open on desktop , so it have better view of websites.
These are better ergonomically because the monitor and keyboard can be adjusted.
Disadvantage - :
No portable , no easy to carry ( cause heavy weight ).
Hard to use in standing position.

27. Network issues and communication
We are going to look here problems associated with the network.
Security issue regarding data transfer
If one computer network together with the another computers then there can be thread of
security breach.
If the computer network is connected with the internet then the security risk is even greater.
Security can be compromised in the following ways :
Password interception
We have different password on the internet for chatting, online banking and the other stuff. If
these password are known by the others then they can read your mails, remove your pics , and
money can be stolen from your bank account.

28. Virus Attack
Virus are major thread for any network . Its an program (instruction of the codes ) who make
itself replicates and then may cause of different damages to the computer and the network.
Some following damages are can be done by the virus :
oDisplay annoying messages on the screen
oDelete your program and data
oUsing computer resources , so it make it slowly.
oSpy on user , to collect the information about the password and other details.
Viruses are going to be created everyday and the every virus have their own damages so you
cannot say what will be the damages will be going to occur cause of the virus.
We must have anti-virus on our computer these antiviruses s/w can detect the virus and delete
it . We must have to upgrade the definition of our antivirus , cause the old anti virus cannot
detect the new developed viruses.

29. Virus Attack
How to prevent from virus :
oInstall anti-virus s/w
oDo not open the e-mails from unknown sources.
oKeep upgrade your antivirus.
oHave a clear policy for the employees.
oDo not allow the video , games and other things on the organization system.
oDo not open the attachment of e-mail from the unknown resources.
oAvoid to users to use their own removable media in the organization computer network.

30. Hackers accessing the network
Hacking the process to access the computer system without the permission from the user.
In most cases hackers are going to try user password or they have cracking program by that they
can generate millions of the possible password and try each of them in the turn.
Sometime key-logging or spyware software are installed on the victim computers , and victim is
don’t have knowledge about this and in this case whatever the victim pressing the key on
keyboard its going to be recorded .
Now these record keys hackers can use to extract password , card details and other personal
data.
Use firewall : A firewall can be an s/w or h/w or both , that going to look the data packet is send
or received by the computers . It can allow or block the data . It logs the data is leaving and the
data sent from the computer. It means it can detect unknown IP address and also stop the user
for accessing unauthorized sites.

31. Hackers accessing the network
Use anti-spyware: This is the special s/w that you can run on your computer , it detect and
remove any spyware program , if your computer have. Spyware s/w is used for collecting the
password and other information by the crackers.
Change password regularly: Its an good habit to change your password in regular intervals
,cause suppose if your password is compromised then still he can use your password for short
while.

32. Protecting access by using user-IDs/usernames and password
System security is making sure that only authorized peoples can log in there system so regarding
that the system have user ids and password.
Identifying user to the system(User – IDs): A user id is the name or the number given by the
system administrator . Some privileges are going to give by the system administrator on the
network.
The network manager can be track the account activity done by certain user account, So he can
also track the improper use of the internet.
Preventing unauthorized access(The use of password): A password can be combination of the
letters , symbols and the numbers , its depend on the choice of the user. Whenever user enter
his password for login into the system its showing that password an asterisk signs.
If the password is wrong then the user cannot login the account , some networks are set up like
this that if the user enters the password three time wrong then the account going to be locked.
If user is genuine then he have to contact to network administrator and reset the password.

33. Protecting access by using user-IDs/usernames and password
Choosing a password (Strong vs. week password): There are so many programs are available by
that crackers can easily crack your password , it means if you are only using letters for the
password it can be easily cracked.
Weak passwords examples :
Amit
Shaolin
Angelina
A strong password does not mean to be long , it means itmust have symbols , letters , numbers.
If crackers attack on your computer and find out its not easy to crack your password then its
going to move another computer with weak passwords.
Strong passwords example :
D%2Gt^Ul

34. Authentication techniques
Many networks have the magnetic stripe card or ID card for entry in the system , but these
system also have username and password in the case of card have been stolen.
Biometric is an good choice for identifying the user , it can use the retinal scanning and
fingerprint scanning . Face recognition can be also used to identify the user.
Iris scanning is better then the retinal scanning because it can be carried out with regular video
cameras and even far as two feet and with the wearing glasses.
Advantage of biometric is that there is nothing to forget.

35. Encryption
The information needs to be secure when its going to travel on network , that’s why we are
using the method encryption.
Encryption scrambles the data and then send to the true receiver , now only he can unscramble
it.
If this data is interfere by any cracker , it will be meaningless to him.
This process is known as encryption.
It requires encryption and decryption keys for both ends.
Encryption used in many fields :
A. Sending card detail (For online shopping)
B. Online banking (fund transfer and other banking activities)
C. Confidential e-mails.

36. The Principles of a typical data protection act
The worldwide so much data travel on the internet ,for protection of the data against the
criminals , Many countries introduced the laws that laws are known as data protection act.
What is personal data:
A. Data about an identifiable person (Like : name , address , phone number)
B. Online banking (fund transfer and other banking activities)
C. Data that is more personal (Like : medical records , criminal records ,religious beliefs etc.)
The effect of wrong personal data:
A. Your medical record can be wrong , so you can get wrong treatment.
B. Wrong exam results can spoil your life.

37. Rights of the data subject and the holder
The person about whom the personal details are held is called subject.
The person in the organization who is holding this data is known as data holder.
A data protection act is a law that protect your data in the following ways :
Registration : Who is going to use the personal data that person must be registered to the data
holder. They must have to explain that for what cause they want this data and what are they
going to do with that data.
Individual can see their data : Anyone can apply for see their personal information that is hold
by the data holder , if there is something inaccurate then subject can correct it , but in some
condition you cant see your records like: any criminal cant see what the record police have
about you.
Data must be secure and up – to -date: Subject can took the organization in the court , if his
data not going to be secure by the organization.
Right for a person to claim compensation: If data processed unlawfully then subject could claim
for the compensation.

38. Network communication
There are different method provided by ICT for communication.
Physical fax : A physical fax contains a scanner , printer and modem . Firstly the document is
going to be scanned and then modem converts the data into a series of the sound that are send
along with the telephone lines.
To send the fax you have to enter the receiver fax machine number at the receiving end . The
modem at the other end converts the sound back into the data and then printer prints the
document.
At one time only one fax can be send or received.
Electronic/Internet faxing: Its used internet technology rather then the phone network for
sending and receiving the fax . All you need send the fax is a computer or mobile device which
have the internet.

39. Difference between physical fax & electronic fax
Electronic fax Physical fax
Its required the use of a computer network Its not required.
No phone lines are required. Phone lines required
You can print or save , its your choice. All physical faxes are printed
No machine is required Physical fax machine required.
More then one fax can send or receive Only one fax at a time

40. Email
An email is an electronic message send from one communication device to another one.
Advantage over to faxing:
1. Emails can be viewed without others seeing them but fax are usually print out when
everyone watching it.
2. Email can be viewed on portable device but physical fax can only be obtain by the fax
machine.
3. The receivers machine may be out of the paper. But emails don’t have that problems.
4. E-mail is cheap but one fax include the cost of phone lines , paper and ink.
Disadvantage:
1. Emails can spread the virus but faxing cannot do that.
2. Faxed signed document are legal but e-mails not

41. Video conferencing
Video –conferencing allow people to communicate with each other while they are in different
places , its provide real time , it means you can see each other. Peoples can share the data
while they are talking with each other.
It allow peoples to conduct virtual meetings. Desktop video conferencing include : Video card ,
sound card , webcam, microphone and s/w.
Advantage over to faxing:
1. Less stress for the employees , no worries to reach office.
2. Improved family life , more time can spend with family.
3. Save travelling time and money does not spend money for hotels.
4. Meeting can be called on short notice.
5. More environment friendly cause less peoples are travelling.
6. Fewer journey means less traffic jam.

42. Video conferencing
Disadvantage:
1. The initial cost for the equipment's is high.
2. Poor image and video quality.
3. People feel self-conscious.
4. Actual product cannot can not pass around between the members.
5. Lack face to face contact.
6. Synchronization problem with audio and video.

43. Web conferencing
Web conferencing is service that allow conferencing events to be shared with users who are in
remote location by using internet.
Usually there will be one sender and many receiver. Web conferencing is used for : Meeting ,
Lectures , Training events. We can share all type of data like voice , video , audio .
Audio conferencing:
It allow to conducting a meeting held by peoples in different locations. That allow to send the
voice.

44. Policing the internet
Many peoples think that there should be policing on the internet cause there are so many undesirable
site , But some other peoples think that user have to choose which information he / she want to
access.
There are two opinions , let see :
Yes , the internet should be policed:
Children can see vulgar movies.
Film , TV everything is regulate so internet should be regulate also.
There are lots of misinformation.
Every activities in society are policed so internet should be policed.
There are many undesirable websites which are going to tell you how to make explosive and other
things.
No , the internet should not be policed:
It is up to people what they want to see or read.
What is allowed in one country is not allowed in other country so you could not agree on what to
police do.
Free speech is fundamental right, it should not be removed.