internet

Communication Technology.

Internet: A worldwide collection of networks that links millions of businesses, government agencies, educational institutions and individuals.

Advantages:
- Easy access to many type of information.
- Services.
- Buy or sell products.
- Downloading Software.

Disadvantages:
- Theft or Personal Information.
- Spamming.
- Virus Treat.
- Pornography.

Intranet: A network that belongs to an enterprise and is an accessible only by that enterprise’s employees or authorized users.
Firewalls: Software and hardware that allows only those external users with specific characteristics to access a protected network.

Extranet: An intranet that is at least partially accessible to authorized outsiders. (Suppliers, customers and business partner.)

Categories	Intranet	Extranet	Internet
Definition	A network that belongs to an enterprise and is accessible only by that enterprise’s employees or authorized users.	A private network that connects more than one organizations that use Internet technologies to allow suppliers, customers and business partner limited access to their network.	The largest and most well-known computer network, linking millions of computers all over the world.
Types of users	Authorized employees only.	Authorized groups from collaborating companies.	Any individual with dial-up access or LAN.
Usages	Provide information for organization employees, (Telephone directories, Employee Information, E-mail)	Provide information to suppliers, customers and business partner. (Access data, check status place order, send E-mail.)	Provide information for public. (Access all kinds of information.)
Security	Higher – Security control over higher.	High – Security control are high.	Loose – Security control is lower.
Types of access	Private and restricted.	Private and outside authorized partners.	Unlimited, public and no restrictions.
Information	Specific, corporate and proprietary.	Shared in authorized collaborating group.	General, public and advertisement.

Internet Connection.

Various/Types of Internet Connection

Transmission Media

Type of physical system used to carry a communication signal from one system to another.

Communication Device

Hardware component that enables a computer to send and receive data, instructions to and from one or more computers.

Internet Service Provider (ISP)

A business that provides individuals and organizations access to the Internet free or for a fee.

Data Transfer Rate

The speed at which data can be transmitted between devices.

High-Speed Broadband Connection

Cable Internet Service (Cable)

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

Physical: Coaxial Cable

Wireless: Communication Satellite (MEASAT Satellite)

Cable Modem

Dish-Shaped Antenna: (Satellite Dish)

Astro: Astro TV, Astro Beyond, IPTV

128 Kbps to 52 Mbps

Digital Subscriber Line (DSL)

Provides high-speed Internet connections using regular copper telephone lines.

Physical: Unpaired Twisted Pair Cable

Wireless: Broadcast Radio (Wi-Fi)

Network Interface Card (NIC)

Wireless Adapter Card

Wireless Access Point

TMNet: Streamyx

128 Kbps to 8.45 Mbps

Cellular Radio Network

Offers high-speed Internet connections to devices with built-in compatible technology or computers with wireless modems.

Cellular Radio: High-frequency radio waves (2G, 3G & 4G)

Wireless Modem

Celcom, Maxis, Yes, P1

2G: 9.6 Kbps to 19.2 Kbps

3G: 144 Kbps to 2.4 Mbps

4G: Up to 15 Mbps

Fibre To The Premises (FTTP)

Uses fibre-optic cable to provide high-speed Internet access to home and business users.

Physical: Fibre-Optic Cable

Cable Modem (BTU: Broadband Termination Unit)

Wireless Access Point: (Residential Gateway: RG)

TM Unifi

5 Mbps to 100 Mbps

Wi-Fi (Wireless Fidelity) Network uses radio signals to provide high-speed Internet connections to compatible or properly equipped wireless computers and devices.	Wireless: Broadcast Radio (Wi-Fi)	Wireless Adapter Card Wireless Access Point	TMNet Hotspots, P1, Yes	802.11: Series of Standards 802.11: 1 to 2 Mbps 802.11a: Up to 54 Mbps 802.11b: Up to 11 Mbps 802.11g: 54 Mbps & higher 802.11n: 108 Mbps & higher
Fixed Wireless Provides high-speed Internet connections using a dish-shaped antenna on your house or business to communicate with a tower location via radio signals.	Radio Signals	Dish Shaped Antenna : (Satellite Dish) Tower Location		256 Kbps to 10 Mbps
Satellite Internet Service Provides high-speed Internet connections via satellite to a satellite dish that communicates with a satellite modem.	Satellite	Satellite Modem Satellite Dish		1 Gbps
Low-Speed Internet Connection
Dial-Up Connection	Physical: Unpaired Twisted Pair Cable	Telephone (Dial-Up) Modem	Telekom Malaysia	Limited to 56 Kbps

The use of Internet:
- View web pages on the WWW (World-Wide-Web)
- Sending and receiving e-mail messages. Sharing files.
-Communicating using voice (VoIP) and video (video-conferencing).
- Playing multi-player games.
- Listening to streamed music or watching streamed video.

Data Transfer Rate: The speed at which data can be transmitted between devices.

Type of line	Transfers Rate
Digital Subscriber Line (DSL)	128 Kbps to 8.45 Mbps
Fiber to the Premises (FTTP)	5 Mbps to 100 Mbps
Fixed Wireless	256 Kbps to 10 Mbps
Cellular Radio Network	2G: 9.6 Kbps to 19.2 Kbps 3G: 144 Kbps to 2.4 Mbps 4G: Up to 15 Mbps
Wi-Fi (Wireless Fidelity)	802.11: Series of Standards 802.11: 1 to 2 Mbps 802.11a: Up to 54 Mbps 802.11b: Up to 11 Mbps 802.11g: 54 Mbps & higher 802.11n: 108 Mbps & higher
Satellite Internet Service	1 Gbps

Internet Service Provider (ISP).

- Internet Service Provider (ISP): A business that provides individuals and organizations access to the Internet free or for a fee.

Regional ISP: Provides Internet access to a specific geographic area.
National ISP: A business that provides 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 for the connection service.
- To protect their site and network from external threats such as viruses, hacker attacks and other illegal activities.
- To provide 24-hour customer service and technical support.

- Examples of ISP in Malaysia:
- Telekom Malaysia (Dial-Up Access)
- TMNet
- TimeNet
- Maxis
- Celcom
- P1
- DiGi
- umobile

Internet Protocol Address.

- IP address: A number that uniquely identifies each computer or device connected to the Internet.

- Why does IP address exist:
It exists as the Internet relies on an addressing system much like the postal service to send data and information to a computer at a specific destination.

- What does an IP address consist of:

IPv4: Uses 32-bit addresses, have 4 parts separated by periods (.), It’s allows for possible unique addresses.
E.g.: 72.14.207.99

Value of first octet	Class	Default subnet mask	Number of host	Used by
1-127 (21.255.255.255)	A (100.100.100.100)	255.0.0.0	16 777 214	Large corporations and government
128-191 (172.255.255.255)	B (150.150.150.150)	255.255.0.0	65 534	Large network
192-223 (211.255.255.255)	C (200.200.200.200)	255.255.255.0	254	Small network

IPv6: Uses 128-bit addresses, have 8 parts separated by colons (:), It’s allows for possible unique addresses.
E.g.: 2001 : 0db8 : 3c4d : 0015 : 0000 : 0000 : abcd : ef12

Example:

1. Longhand notation: 0:0:0:0:0:0:0:1
Shorthand notation: 1

2. Longhand notation: 2001:DB8:0:0:0:0:340:ab
Shorthand notation: 2001:DB8::340:ab

- The transition from IPv4 to IPv6 is necessary because of the vast amount number of devices connecting to the Internet today.

- Domain Name: The text version of an IP address.
IP address: 72.14.207.99
Domain Name: www.google.com

Every domain name contains a top-level domain (TLD), which is the last section of the domain name.
A generic TLD (gTLD), identifies the type of organization associated with the domain name.
In the domain name www.google.com, the top-level domain is ‘.com’.

The domain name system (DNS) is the method that the internet uses to store domain names and their corresponding IP addresses.

A DNS server translates the domain name to its associated IP address so that data and information can be routed to the correct computer.

A DNS server is an Internet server that usually is associated with an Internet service provider.

The similarities between IP address and domain name:
- Unique
- Used as computer address or web page address

.biz: Business of all sizes
.com: Commercial organizations, businesses and companies
.edu: Educational institutions
.gov: Government agencies
.mil: Military organizations
.org: Non-profit organizations.
.fm: FM radio stations and streaming audio websites

ccTLD: Identifies the country of the website. Example .my for Malaysia.

.my: Malaysia
.jp: Japan
.uk: United Kingdom
.sg: Singapore
.id: Indonesia
.au: Australia

World Wide Web (WWW)

- WWW: Consists of a worldwide collection of electronic documents.
- Web Terms: Each electronic document on the web, which can contain text, graphics, animation, audio and video.
- Web Site: Is a collection of related web pages and associated items, such as documents and pictures, stored on a web server.
- Web Server: A computer that delivers requested web pages to your computer.
- Web 2.0: Web sites that provide a means for users to interact (social networking web sites, wikis).

- How do we browse the web?
A web browser/browser is an application software that allows users to access and view web pages and web 2.0 programs.
The primary purpose of a web browser is to display information resources to the users through retrieving, presenting and navigating information.

- Web browser will retrieve and display a starting web page called the home page.

- A home page, refers to the first page that a web site displays that provides information about the web site’s purpose and content.

- A home page usually contains links to other documents, web pages or websites. A link, short for hyperlink, is a built-in connection to another related web page or part of a web page.

- Example of web browser: Internet Explorer, Safari, Google Chrome, Opera, Firefox

- Internet-enabled mobile devices such as smart phones use a special type of browser, called a microbrowser, which is designed for their small screens and limited computing power.

- Downloading is the process of receiving information, such as web page from a server on the internet.

- Uploading is the process of transferring documents, graphics and other objects from a computer to a server on the Internet.

Web Address

- Web Address: A unique address for a web page, also called a URL (Uniform Resource Locator)
Consists of:
- A protocol
- Domain Name
- Path to a specific Web
- Web page name or file name

- Many web page address begin with ‘http://’
http: hypertext transfer protocol
- A set of rules that defines how pages transfer on the Internet.

- Example:
http://www.nps.gov/grsm/playnyourvisit/wildlifeviewing.htm

Protocol: http://
Domain name: www.nps.gov/
Path: grsm/playnyourvisit/
Web page name: wildlifeviewing.htm

Difference between Http and Https protocol:

Http: Hypertext Transfer Protocol
- Used to transmit web pages.
Https: Hypertext Transfer Protocol over SSL (Secure Socket Layer)
- Used to create secure connections for e-commerce.

Web Page Navigation

- Navigating web pages:
Most web pages contain hypertext or hypermedia links.

A link, short for hyperlink, is a built-in connection to another related web page or part of a web page.
Links allow you to obtain information in a nonlinear way.
Surfing the web, refers to the activity of using links to explore the web.
A link can be text or an image.
Text links may be underlined and/or displayed in a colour different from other text on web page.
Tabbed browsing allows you to open and view multiple web pages in a single web browser window.

- Difference between Hypertext links and Hypermedia links:

Hypertext	Refers to links in text-based documents It is a text which contains links to other texts
Hypermedia	Combines text-based links with graphic, audio and video links. Contain links not only to other pieces of text, but also to other forms of media – sounds, images and movies.

Information Searching

- Search tools:

Search engine: Finds information related to a specific topic.

Subject directory: Classifies web pages in an organized set of categories.

- Searching the web:
A primary reason that people use the web is to search for specific information, including text, pictures, music and video.
A search tool is used to locate the information.

- Search engine: A program designed to locate information on the web.

- Searching information using search engine:
- Search engines require that you enter a word or phrase, called search text or search query
- Each word in the search text is known as a keyword.
- The results of the search, called hits.
- Result from the search engine can be in the form of: images, videos, audio, publications, maps, people or businesses, blogs.

- Example of search engine:

Search Engine	Web Address
Google	www.google.com
Yahoo!	www.yahoo.com
Excite	www.excite.com
Lycos	www.lycos.com
HotBot	www.hotbot.com
Webcrawler™	www.webcrawler.com
Bing	www.bing.com

Search Engine Operators
Operations	Description	Examples	Explanation
Space or +	Display has that include specific words.	Art + music Art music	Results have both words art and music – in any order
OR	Display hits that include only one word from a list.	Dog OR puppy Dog OR puppy OR canine	Results have either the word dog or puppy. Results have the word dog or puppy or canine.
()	Combine hits that include specific words with those that include only one word from a list.	Kalamazoo Michigan (pizza OR subs)	Results have both words Kalamazoo Michigan and other the word, pizza or the word subs.
-	Exclude a word from the search results	Automobile - convertible	Results include automobile but do not include convertible.
“ “	Search for an exact phase in a contain order.	“19^th century literature”	Results have the exact phase, 19^th century literature.
/	Substitute characters in place of the extense.	Writer/	Results include any word that begins with writer. (e.g. writer/writers/ writer’s)

- Subject directory: Search tool that classifies web pages in an organized set of categories and subcategories.

Subject Directory	Web Address
Yahoo!	www.yahoo.com
Excite	www.excite.com
Gigablast	www.gigablast.com
MSN	www.msn.com
Open Directory Project	www.dmoz.org

- A subject directory provides categorized lists of links arranged by subject.

- When click on the category link, the subject directory displays a list of subcategory links.

- The disadvantage: Users have difficulty deciding which categories to choose from the menus of links presented.

- Different ways of information searching:
1. Search engine: Finds information related to a specific topic.
2. Subject directory: Classifies web pages in an organized set of categories.

- Good qualities of search engine:
- Have a large database
- Able to provide up to date web sites.
- Able to search in a very short time.