3.2.1 The Internet

Chapter Three

3.2 The Internet3.2.1 Overview of the Internet

3.2.1.1 Introduction to the Internet

At the end of this topic, students should be able to:

Explain about the Internet

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What to cover?

• Definition of Internet• Advantages and disadvantages of Internet• Intranet & extranet

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The Internet

• The Internet is a worldwide collection of networks that links millions of businesses, government agencies, educational institutions, and individuals

Discovering Computers : Chapter 2Page 74 Figure 2-1

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Evolution of the Internet

1969 ARPANET becomes functional

1986 NSF connects NSFnet to

ARPANET and becomes known as

the Internet1996 Internet2 is

founded

Discovering Computers : Chapter 2Pages 75 - 76

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• Vast amounts of data can be stored and processed quickly and efficiently

• Information is available 24 hours a day through access on the Internet or home computer files or office/ workshop servers and computer facilities

Advantages of Internet

Accessibility

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• Decreases in storage costs and increases in Internet connection speeds persuade more users to use cloud storage for their data.

• Web application hosts often store users’ data and information on their servers, which sometimes is called cloud storage.

• Cloud storage also provides users with the convenience of accessing their files from almost anywhere.

Storage


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• You don’t need to leave home to shop – you can shop online and deal with bank transactions and book holidays – an advantage if your are disabled and cannot easily get out.

• You can work from home and use video conferencing/ forum or chat to people across the other side of the world. ( all of which saves money and time)

Online activity


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• Information is readily available, however confidential information may be accessed unless properly password controlled

• In many instances, where personal and confidential records were not protected properly, individuals have found their privacy violated and identities stolen.

Disadvantages of InternetViolation of Privacy

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• Adults, teens, and children around the world are using Internet to share publicly their photos, videos, journals, music, and other personal information. Some of these unsuspecting, innocent computer users have fallen victim to crimes committed by dangerous strangers.

• Protect yourself and your dependents from these criminals by being cautious in e-mail messages and on Web sites.

Public Safety

Disadvantages of Internet

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• Prolonged or improper computer use to access to the Internet can lead to injuries or disorders of the hands, wrists, elbows, eyes, neck, and back.

• Computer users can protect themselves from these health risks through proper workplace design, good posture while at the computer, and appropriately spaced work breaks.

• Two behavioral health risks are computer addiction and technology overload

Health Risks

Disadvantages of Internet

Networks

An intranet is an internal network that uses Internet

technologies

An extranet allows customers

or suppliers to access part of its

intranet

Discovering Computers : Chapter 9 11Page 477

Intranet versus Extranet

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Accessibility

Intranet Information accessible to employees and facilitate collaboration within an organization

Extranet Allow customers and suppliers to access part of intranet

Chapter Three


3.2.1.2 The Internet Connection


Describe different types of Internet connection

1. Dial-up Connection2. Broadband Internet Connection

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Types of Connection and Internet Access

1.Dial-up Connection

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1. Dial-up

o PC has to dial via a phone line to connect

o Conventional dial-up Slower, but cheaper Ties up phone lines Relatively secure from hackers

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2. ISDN

o Also transfer data over ordinary telephone lines

o Typically uses two phone lines to transfer data

o ISDN requires a special ISDN modem Faster, but pricey Doesn’t tie up phone line Used by businesses and individuals

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Advantages Disadvantages• Security• Include inexpensive

hardware• Ease of setup and use• Widespread availability

• Slow connection speed (max of 56Kbps)

• Inconvenience • Telephone line will be

tied up while accessing the Internet

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Advantages & disadvantages of Dial-up Connection

• Also refer to Direct Connection or always-on connections.

• Many home and small business users connect to the Internet via high-speed broadband Internet service

• PC is continually connected to the Internet• Used in the home and office• Because you are always connected, it is important

to protect your computer from hackers

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2. Broadband Internet Connection

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• Types of broadband connection

Discovering Computers : Chapter 2Page 76

DSLFiber to the

Premises (FTTP)

Fixed wireless

Cellular Radio

Network

Cable Internet service

Wi-FiSatellite Internet Service

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• DSL – Digital Subscriber Line• Broadband delivered over telephone lines

o Must be less than 3 miles from a switching stationo Transmits over telephone lines but does not tie up the

line• Fast, direct Internet access via standard telephone

line• ADSL (asymmetric digital subscriber line) is one of

the more popular types of DSLs.

DSL

How the Internet OperateHow might data travel the Internet using atelephone line connection?

Step 1. Request data from a server on Internet

Step 5. Regional ISP uses leased lines to send data to a national ISP

Step 6. National ISP routes data across the country

Step 8. Server sends data back to you

Step 2. Modem converts digital signals to analog signals

Step 3. Data travels through telephone lines to a local ISP

Step 4. Data passes through routers

Step 7. National ISP passes data to local ISP

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• Also known as Broadband over Fiber (BoF)• Delivers over fiber-optic cabling all the way to the

buildingo Available in limited areaso Fast but expensive

• Uses fiber-optic cable• Provide high-speed Internet access to house and

business users.

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Fiber to the Premises (FTTP)

• Uses radio transmission towers rather than satellites

• Not available in all areas.• Expected to use Worldwide Interoperbility for

Microwave Access (WiMAX)• Provides high-speed Internet connections using a

dish-shaped antenna to communicate via radio signals.

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Fixed wireless

• Also known as Mobile wireless • Access via mobile phone or mobile device• Offers high-speed Internet connections to devices

with built-in compatible technology or computers with wireless modems.

• Categories : 1G, 2G, 3G, 4G, 5G.

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Cellular Radio Network

• Cable: Most widely used home broadband connection

• Provides high-speed Internet access through the cable television network via a cable modem.

• A new technology in Malaysia

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Cable Internet Service/ Cable Modem

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• Data is transmitted through radio waves.• Public wireless networks

o Both free and fee-based are availableo Currently Wi-Fi for short range, but WiMAX may

soon be an option• Provide high-speed Internet connections to

compatible or properly equipped wireless computers and device.

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Wi-Fi (Wireless Fidelity)

• WiFi hotspots are places that provide a user with free or paid Internet services. Eg: Airport, Café, Hotel, hostel, Offices and other public buildings.

Wi-Fi Hotspot

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• Broadband option for rural areaso Slower and more expensive than cable or DSLo Available in many areas other broadband

options are not• Provides high-speed Internet connections via

satellite.• A satellite dish communicates with a satellite

modem.

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Satellite Internet service

Common Types of Internet Connections

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Difference between dial-up and broadband

• Dial up connection speed is generally 56k (sometimes slower). Basic entry level speed to Broadband is 256k. The obvious difference here is that the Broadband connection speed is almost 5 times faster than Dial up (Refer to ‘Broadband Speeds’).

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Chapter Three


3.2.1.3 Internet Service Provider


1. Explain the Internet Service Provider.2. List examples of Internet Service

Provider in Malaysia

• Access Providers is a business that provides individuals and organizations access to the Internet for free or for a fee

• Access providers are categorized as regional or national ISPs online service providers wireless Internet service providers

Access Providers

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• An ISP (Internet service provider) is a regional or national access provider.

ISP (Internet service provider)

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Regional ISPs provide Internet access to a

specific geographical area

National ISPs provide Internet access in cities and towns nationwide

Responsibilities of an ISP

• Providing and maintaining a connection to the Internet• Support the hardware and software needed to service that

connection• To protect their site and network from external threats

such as viruses, hacker attacks and other illegal activities• Provide 24-hour customer service and technical support

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Examples of ISP in Malaysia

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• TMNet• TIME• Maxis• Celcom• Jaring• Digi• Packet One Network• Umobile• YTL

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Page 78

• In addition to providing Internet access, an online service provider (OSP) also has many members-only features such as instant messaging or their own customized version of a Web browser.

• A wireless Internet service provider, sometimes called a wireless data provider, is a company that provides wireless Internet access to desktop and notebook computers and mobile devices, such as smart phones and portable media players, with built-in wireless capability (such as Wi-Fi) or to computers using wireless modems or wireless access devices.

OSP & Wireless ISP

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Online service provider (OSP)

Has many members-only features

Popular OSPs services include

Wireless Internet service provider

Provides wireless Internet access to computers and

mobile devices

May require a wireless modem

Discovering Computers : Chapter 2Page 78

Chapter Three


3.2.1.4 The Internet AddressAt the end of this topic, students should

be able to:1. Identify the structure of IP address2. Describe the purpose of an IP address

and its relationship to a domain name

Internet Address

The protocol that provides for addressing and routingInternet packets from one

computer to another

IP(Internet Protocol)

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A standard that outlines characteristics of how two network devices communicate is called a protocol.

• your computer must have an IP address (Internet Protocol address)to connect to the Internet or another computer that has an IP address.• IP address has four parts number, separated by periods• First portion of each IP address identifies the network• Last portion identifies the specific computer• The number in each group is between 0 and 255

A number that uniquely identifies each computer or device connected to the Internet

Definition of IP address

A unique 32-bit number assigned to network devices that use Internet Protocol

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**These all-numeric IP addresses are difficult to remember and use. Thus, the Internet supports the use of a text name that represents one or more IP addresses, known as Domain Name.

0.0.0.0 (default network)

127.0.0.1 (for testing as a loopback address)

255.255.255.255 (network broadcast) Special reserved IP addresses10.0.0.0 to 10.255.255.255

(private networks)

172.16.0.0 to 172.31.255.255 (private networks)

192.168.0.0 to 192.168.255.255(private networks)

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Domain name • The text version of an IP address• The text in the domain name up to the first period identifies the

type of Internet server.• Every domain name contains a top-level domain (TLD), which is

the last section of the domain name. It is used usually to identify the type of organization associated with the domain.

• You register for a domain name from a registrar, which is an organization that sells and manages domain names.

Domain Name System (DNS)• Method that the Internet uses to store domain names and their

corresponding IP addresses.• translates the domain name into its associated IP address.

Domain Name System (DNS) ServerA server on the internet that usually is associated with an ISP.

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173.194.78.103

Top-level domain (TLD)

The last section of the domain name

Example :my – Malaysiaau – Australiasg – Singapore

Purpose of Top-level domain (TLD)

Country Code Top-

level domain(ccTLD)

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Identifies the type of organization associated with the domain

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How IP address, domain name and Domain name Server works

Examples of Top Level Domain

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TLD for music and online broadcasting

• .fm• .ikim• .astro

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Version 4 of Internet Protocol,the most widely

used version of IP

Version 6 of Internet Protocol,

has more capabilities than IPv4, including

providing for farmore IP address

IPv4 IPv6

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Currently, two versions of IP addresses exist: IPv4 (Internet Protocol Version 4) and IPv6 (Internet Protocol Version 6). An IPv4 address has two parts that identify a specific computer: one part to identify the network where that computer resides and a second part to pinpoint the specific computer or host within that network.Because each of the 8 bits can be 1 or 0, the total possible combinations per octet are 28, or 256. Combining the four octets of an IP address provides a possible 232 or 4,294,967,296 unique values.

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Billions of IP addresses sounds like a lot. But, because so many computers and other devices connected to the Internet need unique IP addresses, a growing shortage of IP addresses exists.

An IPv6 address has three parts: a global prefix to identify the network, a subnet to identify the location within the network, and the interface ID to identify the specific computer or host. IPv6 will use 216 (hexadecimal) is 128 bits address. Combining the eight octets of an IP address provides a possible 2128 which will provide 3.4 x 1038, or 340,000,000,000,000,000,000,000,000,000,000,000,000 IP addresses.

Education

3.2.1 The Internet