The internet and world wide web: e

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Transcript The internet and world wide web: e

Chapter 3
Learning Objectives
• Discuss the origins of the Internet
• Identify the key technology concepts behind the Internet
• Discuss the impact of the mobile platform and cloud
• Describe the role of Internet protocols and utility programs
• Explain the current structure of the Internet
• Understand the limitations of today’s Internet
• What is the Internet?
• How is it different from other computer networks?
Internet vs. Web
• The Internet is an interconnected network of thousands of
networks and millions of computers (sometimes called
host computers) linking businesses, educational
institutions, government agencies, and individuals
• The Internet provides approximately 2.56 billion people
around the world with services such as e-mail, apps,
newsgroups, shopping, research, instant messaging,
music, videos, and news
• The World Wide Web, or Web for short, is one of the
Internet’s most popular services providing access to
billions of Web pages that contain text, multimedia
content, services, and hyperlinks to other pages
The Evolution of the Internet
• Innovation phase (1961-1974)
• Fundamental building blocks are conceptualized and implemented
• Linked mainframe computers on different college campuses
• Institutionalization phase (1975-1995)
• Large institutions such as the DoD and NSF provided funding and
• Use steadily increased
• Commercialization phase (1995-present)
• Private corporations began to take over and expand both the
Internet backbone and local service to ordinary citizens
• Created an online marketplace
Development of the Internet Timeline
(Table 3.2)
• Some examples of key developments include:
• 1961, concept of packet switching is created
• 1969, first packet-switched message is sent on ARPANET from
UCLA to Stanford (Internet born)
• 1972, e-mail is invented
• 1974, TCP/IP invented
• Late 1970s, PCs are invented
• 1984, Domain Name System (DNS) system introduced
• 1989, the Web is created
• 1993, first graphical Web browser (Mosaic)
• 1994, first banner ad (birth of e-commerce)
• 1995, NSF privatizes the backbone (fully commercial Internet born)
Key Internet Technology Components
• Packet switching
• TCP/IP and domain names
• Internet architecture and applications
• Client/server architecture
• Mobile platform
• Cloud computing
Packet Switching
• Packet switching is a method of slicing digital messages into discrete
units called packets, sending the packets along different
communications paths, and then reassembling the message at the
• While packet switching was an enormous advance in
communications capacity, there was no universally agreed
upon method for breaking up digital messages into
packets, routing them to the proper address, and then
reassembling them into a coherent message
• The answer was to develop a protocol
• The transmission control protocol (TCP) establishes the
connections among sending and receiving machines, and
makes sure that packets sent by one computer are
received in the same sequence by the other, without any
packets missing
• The Internet protocol (IP) provides the Internet’s
addressing scheme
IP Addresses
• An IPv4 Internet address is a 32-bit number that appears
as a series of four separate decimal numbers marked off
by periods, such as
Each of the four decimal numbers can range from zero to
This IPv4 addressing scheme supports up to about four
billion unique addresses (2 to the 32nd power)
A new version, called IPv6, was developed to expand the
number of addresses available
It uses 128-bit addresses so it can support up to 3.4 x
1038 addresses, many more than IPv4
Domain Names
• Most people cannot remember 32-bit (or 128-bit)
numbers, so an IP address can be represented by a
natural language convention called a domain name
• The Domain Name System (DNS) allows expressions
such as to stand for a numeric IP address
• Web pages use domain names as part of their unique
Uniform Resource Locator (URL)
Uniform Resource Locators (URLs)
• An example URL would be:
• This can be interpreted as:
• protocol://domain/path/file.extension
• Domains are classified most commonly as either .com,
.org, .net, .edu, .gov, .mil
• Domains outside the US often include a country
classification such as .uk (United Kingdom) or .ca
(Canada) at the end of the URL
• Easy to expand capacity
• Less vulnerable than centralized computing architectures
• Processing load is balanced over many powerful smaller
The New Client: The Mobile Platform
• In a few years, the primary means of accessing the
Internet worldwide will be through highly portable
smartphones and tablet computers, and not traditional
desktop or laptop PCs
• In 2013, there are an estimated 4.3 billion worldwide
mobile phone users, with 247 million in the US
• Smartphones are disruptive because they do not use the
same processors, operating systems, and storage
devices that PCs use
• The mobile platform has profound implications for ecommerce because it influences how, where, and when
consumers shop and buy
The Internet “Cloud Computing” Model:
Software and Hardware as a Service
• Cloud computing refers to a model of computing in which
firms and individuals obtain computing power and
software applications over the Internet
• Traditionally, users would purchase hardware and then
install software on their own machines
• Currently, cloud computing is the fastest growing form of
computing, with an estimated market size in 2013 of over
$130 billion
Cloud Computing Benefits and Risks
• Radically reduces the cost of building and operating Web
sites because the necessary hardware infrastructure and
services can be licensed from Internet service providers
at a lower cost
• Individuals can use much less-expensive tablet
computers or smartphones for e-commerce activities
• Corporations can significantly cut their hardware and
software costs (infrastructure costs), and they don’t have
to hire a large IT staff
• A risk is that firms may become totally dependent on their
cloud service providers
Who Governs the Internet?
• It is often claimed that the Internet is governed by no one,
but this is not entirely true
• The Internet is tied to a complex web of governing bodies,
national legislatures, and international professional
• Among the governing bodies of the Internet are:
• The Internet Corporation for Assigned Names and Numbers
The Internet Engineering Task Force (IETF)
The Internet Society (ISOC)
The Internet Governance Forum (IGF)
The World Wide Web Consortium (W3C)
Changes in Internet Governance
• The US Department of Commerce (DoC) originally created
ICANN with the intent that it take temporary control of the
Domain Name System and the 13 root servers that are the
heart of the Internet addressing scheme
Beginning in 2000, ICANN and the DoC suggested they would
turn over control of the DNS to some unspecified international
The US changed its policy in June 2005 when it was
announced that the DoC would retain oversight over the root
In 2014 it was announced that the US is again considering
passing control of ICANN to a global governance organization
What are the advantages and disadvantages of making this
Limitations of the Current Internet
• Much of the Internet’s current infrastructure is several
decades old
• It suffers from a number of limitations, including:
• Bandwidth limitations
• Quality of service limitations
• Network architecture limitations
• Wired Internet
• One proposed solution is Internet2 which is an advanced
networking consortium of more than 350 member
institutions all working in partnership to facilitate the
development, deployment, and use of revolutionary
Internet technologies
The Internet of Things (IoT)
• Internet technology is spreading beyond the desktop,
laptop, and tablet computers, and beyond the
smartphone, to consumer electronics, electrical
appliances, cars, medial devices, utility systems,
machines of all types, and clothing
• IPv6 provides sufficient addresses to connect a vast array
of new devices
• Predictions indicate that there could be up to 100 billion
uniquely identifiable objects connected to the Internet by
• What are the benefits and risks for the IoT?