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Chapter 6 The Cloud
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A personal area network (PAN) connects devices located around a single person. Most
PAN devices connect wirelessly to other devices located within 10 meters. A local area net-
work (LAN) connects computers that reside in a single geographic location on the premises
of the company that operates the LAN. The number of connected computers can range from
two to several hundred. The distinguishing characteristic of a LAN is a single location. A wide
area network (WAN) connects computers at different geographic locations. The computers
in two separated company sites must be connected using a WAN. To illustrate, a smartwatch or
fitness tracker will create a PAN by connecting to a student’s smartphone. The computers for a
college of business located on a single campus can be connected via a LAN. The computers for
a college of business located on multiple campuses must be connected via a WAN.
The single-versus multiple-site distinction between LANs and WANs is important. With a
LAN, an organization can place communications lines wherever it wants because all lines reside
on its premises. The same is not true for a WAN. A company with offices in Chicago and Atlanta
cannot run a wire down the freeway to connect computers in the two cities. Instead, the company
contracts with a communications vendor licensed by the government and that already has lines or
has the authority to run new lines between the two cities.
An internet is a network of networks. Internets connect LANs, WANs, and other inter-
nets. The most famous internet is “the Internet” (with an uppercase letter I), the collection of
networks you use when you send email or access a Web site. In addition to the Internet, private
networks of networks, called internets, also exist. A private internet used exclusively within an
organization is sometimes called an intranet.
The networks that make up an internet use a large variety of communication methods and
conventions, and data must flow seamlessly across them. To provide seamless flow, an elaborate
scheme called a layered protocol is used. The details of protocols are beyond the scope of this text.
Just understand that a protocol is a set of rules and data structures for organizing communica-
tion. Computers need to use protocols so they can exchange data. People use similar protocols to
communicate. People, for example, follow a conversational protocol that says when one person
talks, the other person listens. They switch back and forth until they are done communicating.
Without a protocol for conversations, people would continually talk over each other and nothing
would be communicated.
There are many different protocols; some are used for PANs, some are used for LANs, some
are used for WANs, some are used for internets and the Internet, and some are used for all of
these. We will identify several common protocols in this chapter.

What Are the Components of a LAN?
Employers can and do monitor As stated, a LAN is a group of computers connected together on a single site. Usually the
employees’ online activities. What is computers are located within a half-mile or so of each other. The key distinction, however, is
the purpose of this monitoring, and that all of the computers are located on property controlled by the organization that operates
how is it done? Is there anything
employees can do about it? The the LAN. This means that the organization can run cables wherever needed to connect the
Guide on pages 272–273 considers computers.
these questions. Figure 6-5 shows a LAN typical of those in a small office or home office (SOHO).
Typically, such LANs have fewer than a dozen or so computers and printers. Many businesses, of
course, operate LANs much larger than this one. The principles are the same for a larger LAN, but
the additional complexity is beyond the scope of this text.
The computers and printers in Figure 6-5 communicate via a mixture of wired and wire-
less connections. Some devices use wired connections, and others use wireless connections. The
devices and protocols used differ for wired and wireless connectivity.
The Institute for Electrical and Electronics Engineers (IEEE, pronounced “I triple E”) sponsors
committees that create and publish protocol and other standards. The committee that addresses
LAN standards is called the IEEE 802 Committee. Thus, IEEE LAN protocols always start with the
numbers 802.