The Internet has its roots in a networking project
started by the Pentagon’s Advanced Research
Projects Agency (ARPA), an agency of the U.S.
Department of Defense. ARPA’s goal was to build a
network that (1) allowed scientists at different physical
locations to share information and work together
on military and scientific projects and (2) could
function even if part of the network were disabled
or destroyed by a disaster such as a nuclear attack.
That network, called ARPANET, became functional
in September 1969, linking scientific and academic
researchers across the United States.
The original ARPANET consisted of four main
computers, one each located at the University
of California at Los Angeles, the University of
California at Santa Barbara, the Stanford Research
Institute, and the University of Utah. Each of these
computers served as a host on the network. A host,
more commonly known today as a server, is any
computer that provides services and connections
to other computers on a network. Hosts often use
high-speed communications to transfer data and
messages over a network.
As researchers and others realized the great
benefit of using ARPANET to share data and
information, ARPANET underwent phenomenal
growth. By 1984, ARPANET had more than 1,000
individual computers linked as hosts. Today, more
than 550 million hosts connect to the Internet.
Some organizations connected entire networks
to ARPANET to take advantage of its high-speed
communications. In 1986, the National Science
Foundation (NSF) connected its huge network
of five super computer centers, called NSFnet, to
ARPANET. This configuration of complex networks
and hosts became known as the Internet.
Until 1995, NSFnet handled the bulk of the
communications activity, or traffic, on the Internet.
In 1995, NSFnet terminated its network on the
Internet and resumed its status as a research network.
Today, the Internet consists of many local,
regional, national, and international networks.
Numerous corporations, commercial firms, and
other companies such as IBM provide networks
to handle Internet traffic. Both public and private
organizations own networks on the Internet. These
networks, along with telephone companies such as
Verizon and AT&T, cable and satellite companies,
and the government, all contribute toward the internal
structure of the Internet.
Each organization on the Internet is responsible
only for maintaining its own network. No single
person, company, institution, or government agency
controls or owns the Internet. The World Wide
Web Consortium (W3C), however, oversees research
and sets standards and guidelines for many areas of
the Internet. The mission of the W3C is to contribute
to the growth of the Web. More than 350 organizations
from around the world are members of the
W3C, advising, defining standards, and addressing
other issues.
Internet2
Internet2 is a not-for-profit research and
development project that connects more than 200
universities and 115 companies via a high-speed private
network. Founded in 1996, the goal of Internet2
is to develop and test advanced network technologies
that will benefit Internet users in the short-term
future. These technologies require an extremely
high-speed network that exceeds the capabilities of
today’s Internet and networks. Examples of previous
Internet2 projects that are now mainstream
include telemedicine, digital libraries (online books,
magazines, music, movies, speeches, etc.), and faster
Internet services. Current Internet2 projects include
interactive high-definition video and enhanced
detection and resolution of network problems.
Connecting to the Internet
Many home and small business users connect
to the Internet via high-speed broadband Internet
service. With broadband Internet service, your computer
or mobile device usually is connected to the
Internet the entire time it is powered on. Examples
of broadband Internet service include cable, DSL,
fiber, radio signals, and satellite.
• Cable Internet service provides high-speed Internet
access through the cable television network via a
cable modem.
• DSL (digital subscriber line) provides high-speed
Internet connections using regular copper
telephone lines.
• Fiber to the Premises (FTTP) uses fiber-optic cable
to provide high-speed Internet access to home
and business users.
• 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.
• A cellular radio network offers high-speed Internet
connections to devices with built-in compatible
technology or computers with wireless modems.
• A Wi-Fi (wireless fidelity) network uses
radio signals to provide high-speed Internet
connections to compatible or properly equipped
wireless computers and devices.
• Satellite Internet service provides high-speed
Internet connections via satellite to a satellite dish
that communicates with a satellite modem.
Employees and students typically connect their
computers to the Internet through a business or
school network. The business or school network
connects to a high-speed broadband Internet service.
Many home users set up a Wi-Fi network, which
sends signals to a communications device that is connected
to a high-speed Internet service such as cable
or DSL. Instead of using broadband Internet service,
however, some home users connect to the Internet
via dial-up access, which is a slower-speed technology.
Dial-up access takes place when the modem in your
computer connects to the Internet via a standard telephone
line that transmits data and information using
an analog (continuous wave pattern) signal. Users may
opt for dial-up access because of its lower price or
because broadband access is not available in their area.
Mobile users access the Internet using a variety of
Internet services. Most hotels and airports provide
wired or wireless Internet connections as a service to
travelers. Wireless Internet services, such as Wi-Fi
networks, allow mobile users to connect easily to the
Internet with notebook computers, smart phones,
and other mobile devices while away from a telephone,
cable, or other wired connection. Many public
locations, such as airports, hotels, schools, shopping
malls, and coffee shops, are hot spots that provide
Wi-Fi Internet connections to users with mobile
computers or devices. At public locations, you may
be required to agree to terms of service, obtain a
password (for example, from the hotel’s front desk),
or perform some other action in order to connect to
the Internet. Some cities provide free Wi-Fi Internet
Access Providers
An access provider is a business that provides
individuals and organizations access to the
Internet free or for a fee. For example, some
Wi-Fi networks provide free access while others
charge a per use fee. Other access providers often
charge a fixed amount for an Internet connection,
offering faster speeds or more services for higher
rates. Typical monthly rates range from about
$5 to $24 per month for dial-up, $13 to $70 for
DSL, $20 to $75 for cable, $40 to $150 for FTTP,
$30 to $80 for fixed wireless, $60 to $80 for cellular
networks, and $50 to $120 for satellite. Many
Internet access providers offer services such as
news, weather, financial data, games, travel guides,
e-mail, photo communities, and online storage
to hold digital photos and other files. (A file is a
named unit of storage.)
Access providers are categorized as regional
or national ISPs, online service providers, and
wireless Internet service providers (Figure 2-2).
An ISP (Internet service provider)
is a regional or national access provider.
A regional ISP usually provides Internet
access to a specific geographic area. A
national ISP is a business that provides
Internet access in cities and towns nationwide.
For dial-up access, some national
ISPs provide both local and toll-free telephone
numbers. Due to their larger size,
national ISPs usually offer more services
and have a larger technical support staff
than regional ISPs. Examples of national
ISPs are AT&T and EarthLink.
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. The two more popular OSPs
are AOL (America Online) and MSN
(Microsoft Network). AOL differs from
many OSPs in that it provides gateway
functionality to the Internet, meaning it
regulates the Internet services to which
members have access. AOL also provides
free access to its services to any user with
a broadband Internet connection.
When selecting an ISP or OSP for dial-up
access, ensure it pro vides at least one local
telephone number. Otherwise, long-distance
telephone charges will apply for the time you
connect to the Internet.
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. Wireless modems,
which usually are in the form of a USB flash
drive or a card that inserts in a slot in a computer
or mobile device, generally dial a telephone number
to establish a connection with the wireless
Internet service provider. An antenna on or built
into the computer or device, wireless modem,
or wireless access device typically sends signals
through the airwaves to communicate with a
wireless Internet service provider. Some examples
of wireless Internet service pro viders include
AT&T, Boingo Wireless, Sprint Broadband
Direct, T-Mobile, and Verizon Wireless.
How Data and Information Travel
the Internet
Computers connected to the Internet work
together to transfer data and information
around the world using servers and clients and
various wired and wireless transmission media.
On the Internet, your computer is a client that
can access data, information, and services on a
variety of servers.
The inner structure of the Internet works
much like a transportation system. Just as
interstate highways connect major cities and
carry the bulk of the automotive traffic across
the country, several main transmission media
carry the heaviest amount of traffic on the
Internet. These major carriers of network
traffic are known collectively as the Internet
backbone.
In the United States, the transmission media
that make up the Internet backbone exchange
data and information at several different major
cities across the country. That is, they transfer
data and information from one network to
another until reaching the final destination
Internet Addresses
The Internet relies on an addressing system
much like the postal service to send data and
information to a computer at a specific destination.
An IP address, short for Internet Protocol
address, is a number that uniquely identifies each
computer or device connected to the Internet.
The IP address usually consists of four groups of
numbers, each separated by a period. The number
in each group is between 0 and 255. For example,
the numbers 72.14.207.99 are an IP address. In
general, the first portion of each IP address identifies
the network and the last portion identifies
the specific computer.
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. A domain name is the text version
of an IP address. Figure 2-4 shows an IP address
and its associated domain name. As with an IP
address, the components of a domain name are
separated by periods.
The text in the domain name up to the first period
identifies the type of Internet server. In Figure 2-4,
for example, the www indicates a Web server.
Every domain name contains a top-level domain
(TLD), which is the last section of the domain
name. A generic TLD (gTLD), such as the com in
Figure 2-4 on the previous page, identifies the type
of organization associated with the domain. The
Internet server and gTLD portions of a domain
name often are not required.
The organization that assigns and controls
top-level domains is the Internet Corporation for
Assigned Names and Numbers (ICANN pronounced
EYE-can). Figure 2-5 lists some gTLDs. For TLDs
such as biz, com, info, name, net, and org, you register
for a domain name from a registrar, which is an
organization that sells and manages domain names.
For international Web sites outside the United
States, the domain name also includes a country
code TLD (ccTLD), which is a two-letter country
code, such as au for Australia. For example,
www.philips.com.au is the domain name for Philips
Australia. Some smaller countries have granted use
of their ccTLDs for commercial purposes, such as tv
(Tuvalu) for the television/entertainment industry.
The domain name system (DNS) is the method that
the Internet uses to store domain names and their
corresponding IP addresses. When you specify a
domain name, 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 access provider. For a
more technical discussion about DNS servers, read
the High-Tech Talk article on page 382.
The growth of the Internet has led to a shortage
of IP addresses. Thus, a new IP addressing scheme,
called IPv6, may increase the number of available
IP addresses. For a more technical discussion about
Internet addresses and IPv6,
Hi. I’m Designer of Blog Magic. I’m CEO/Founder of ThemeXpose. I’m Creative Art Director, Web Designer, UI/UX Designer, Interaction Designer, Industrial Designer, Web Developer, Business Enthusiast, StartUp Enthusiast, Speaker, Writer and Photographer. Inspired to make things looks better.
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