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Q6-2 What Network Technology Supports the Cloud?
country as you are. Finally, you have no visibility into the security and disaster preparedness that
is actually in place. Your competition could be stealing your data and you won’t know it.
Storing valuable information online The positives and negatives of in-house hosting are shown in the second column of Figure 6-3.
can be risky. The Security Guide on For the most part, they are the opposite of those for cloud-based computing; note, however, the need
pages 270–271 looks at why your for personnel and management. With in-house hosting, not only will you have to construct your
information may not be as safe as own data center, you’ll also need to acquire and train the personnel to run it and then manage those
you think.
personnel and your facility.

Why Now?

A skeptic might respond to Figure 6-3 by saying, “If it’s so great, why hasn’t cloud hosting been
used for years? Why now?”
In fact, cloud-based hosting (or a version of it under a different name) has been around since
the 1960s. Long before the creation of the personal computer and networks, time-sharing ven-
dors provided slices of computer time on a use-fee basis. However, the technology of that time,
continuing up until the first decade of this century, did not favor the construction and use of
enormous data centers, nor did the necessary Internet standards exist.
Companies can save a lot of money Three factors have made cloud-based hosting advantageous today. First, processors, data
by using the cloud, and these communication, and data storage are so cheap that they are nearly free. At the scale of a Web
savings translate into profit. This farm of hundreds of thousands of processors, providing a virtual machine for an hour costs essen-
profit does not come without ethical
concerns, however. The Ethics Guide tially nothing, as suggested by the 1.5 cent-per-hour price. Because data communication is so
on pages 244–245 examines these cheap, getting the data to and from that processor is also nearly free.
concerns. Second, virtualization technology enables the near instantaneous creation of a new virtual
machine. The customer provides (or creates in the cloud) a disk image of the data and programs
of the machine it wants to provision. Virtualization software takes it from there. Finally, as stated,
Internet-based standards enable cloud-hosting vendors to provide processing capabilities in flex-
ible yet standardized ways.

When Does the Cloud Not Make Sense?

Cloud-based hosting makes sense for most organizations. The only organizations for which it may
not make sense are those required by law or by industry standard practice to have physical control
over their data. Such organizations might be forced to create and maintain their own hosting infra-
structure. A financial institution, for example, might be legally required to maintain physical control
over its data. Even in this circumstance, however, it is possible to gain many of the benefits of cloud
computing using private clouds and virtual private clouds, possibilities we consider in Q6.

Q6-2 What Network Technology Supports the Cloud?

A computer network is a collection of computers that communicate with one another over trans-
mission lines or wirelessly. As shown in Figure 6-4, the four basic types of networks are personal
area networks, local area networks, wide area networks, and internets.

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