Business Data Communications and Networking 11e FitzGerald solutions manual and test bank
Business Data Communications and Networking, 11th Edition
ISBN 978-1-118-08683-4
August 2011, ©2012
http://www.mediafire.com/view/wgkhvxt00l7x6vw/Business_Data_Communications_and_Networking_11e_FitzGerald_solutions_ch02.doc
http://www.mediafire.com/view/gks373qwqi3u87t/Business_Data_Communications_and_Networking_11e_FitzGerald_tbc2.doc
Chapter 2
Application
Layer
True-False Questions
The following are possible True/False
questions for tests. The statement is given and the answer is provided in
square brackets. The level of difficulty (easy, moderate, difficult) and the
page number(s) relevant to the topic are also furnished.
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1.
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An application
architecture is the way in which the functions of the application layer are
performed solely by the clients in the network.
Answer: False
Difficulty: Moderate
Reference:
Application Architectures
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2.
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The four general
functions of any application program are: data storage, data access logic,
application logic and presentation logic.
Answer: True
Difficulty: Easy
Reference:
Application Architectures
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3.
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A cluster is a
group of computers that are linked together so they act as a one computer.
Answer: True
Difficulty: Easy
Reference:
Technical Focus
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4.
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A network
computer is designed primarily to communicate using Internet based standards,
but has no hard disk. It has only
limited functionality.
Answer: True
Difficulty: Easy
Reference:
Technical Focus
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5.
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Host-based and
client-based networks are similar in that the client computer performs most
of the work.
Answer: False
Difficulty: Easy
Reference:
Application Architectures
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6.
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The earliest data
communications networks were client-server networks.
Answer: False
Difficulty: Easy
Reference:
Host-Based Architectures
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7.
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As the demand for
more and more network applications grow; host-based computing becomes the best
solution.
Answer: False
Difficulty: Moderate
Reference:
Host-Based Architectures
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8.
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One major
drawback to a client-server network lies in the fact that client-server
networks enable software and hardware from different vendors to be used
together.
Answer: False
Difficulty: Moderate
Reference: Client-Server
Architectures
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9.
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In a
client-server network, the presentation logic is the responsibility of the
client computer.
Answer: True
Difficulty: Easy
Reference:
Client-Server Architectures
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10.
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The two functions
of middleware are to: 1) provide a
standard way of communicating that can translate between software from
different vendors, and 2) manage the message transfer between clients and
servers so that clients do not need to ‘know’ which server contains the
application’s data.
Answer: True
Difficulty: Moderate
Reference:
Client-Server Architectures
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11.
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Middleware is the
software that sits between the application software on the client and the
application software on the server.
Answer: True
Difficulty: Easy
Reference:
Client-Server Architectures
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12.
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In the three-tier
architecture, the software on the client computer is responsible for the
presentation logic, an application server is responsible for the application
logic and a separate database server is responsible for the data access logic
and data storage.
Answer: True
Difficulty: Moderate
Reference:
Two-Tier, Three Tier, and n-Tier Architectures
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13.
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A “thin client”
approach places most of the application logic on the client.
Answer: False
Difficulty: Easy
Reference: Thin Clients
versus Thick Clients
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14.
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The application
architecture called the distributed computing model uses the “thick” client
approach.
Answer: False
Difficulty: Moderate
Reference: Thin
Clients versus Thick Clients
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15.
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Scalability
refers to the ability to increase or decrease the capacity of the computing
infrastructure in response to changing capacity needs.
Answer: True
Difficulty: Easy
Reference: Scalability
Chapter 2: Application Layer
11th edition
Chapter Outline
INTRODUCTION
APPLICATION ARCHITECTURES
Host-Based Architectures
Client-Based
Architectures
Client-Server
Architectures
Peer-to-Peer
Architectures
Choosing Architectures
WORLD WIDE WEB
How the Web Works
Inside an HTTP Request
Inside an HTTP Response
ELECTRONIC MAIL
How E-Mail Works
Inside an SMTP Packet
Attachments in Multipurpose Internet Mail
Extension
OTHER APPLICATIONS
Telnet
Instant Messaging
Videoconferencing
IMPLICATIONS FOR MANAGEMENT
SUMMARY
Teaching Notes
I usually spend 3 hours of class time on this chapter.
I also include hands-on labs on (1) HTML (using Microsoft Word,
Front Page, or Dreamweaver) to ensure that all students can create their own
web pages and (2) FTP (using both a graphic-interface FTP application and
command line FTP access) to ensure that students can transfer files. Sometimes I include a hands-on Web and e-mail
lab as well.
I have several goals when I teach this chapter. First, I want students to get a sense of the
history of the Internet beyond what they already know. Most of my students think the Internet has
always been there. The “traditional”
history given in Introduction to Computing courses usually mentions that the
Internet started in the late 1960s. This
is true, but can be misleading; it implies the Internet has always been an
important network. I try to show how
small it was at first and illustrate that that it was only one of several
possible networks that could have “won.” I also try to impress upon them the extremely
rapid growth in the past few years. You
might want to update the timeline with more recent statistics on the number of
Internet users. See www.boardwatch.com. It is useful to explain that the Internet was
not originally designed for commercial activities, and that this lack of a
business intent carries over into some of the more difficult aspects of traffic
management and control in today’s environment.
I have two goals for the Internet applications section. First, I want students to become familiar with
the Web, SMTP, FTP, and telnet, although for most students this is remedial. Starting with this material, however, helps
students to understand the importance and relevance of the course – everyone
wants to learn more about the Internet.
The Internet applications discussion is also a good place to explain
exactly what is meant by standards and layers from Chapter 1. The HTTP/SMTP standards help students
understand why we need standards and most
importantly that there are standards at all layers in the network model. This underscores the concept that each layer
is distinct and has a packet within a packet within a packet, something I have
always found that students have difficulty understanding. In my opinion, this concept is more important
than having them memorize the contents and format of each type of packet,
although I require them to be able to explain the parts of the packet and what
each does.
Electronic commerce is an important topic. Most students want to learn about it, and many
have been exposed to it in prior classes. I cover enough to help them sort out what is
going on the Web with respect to the use of the Internet to operate the back
end of businesses using electronic commerce. I also try to link the material to their
marketing or economics courses. We
discuss aspects of purchasing goods over the internet, and I also ask them if
they have purchased anything over the web, used instant messaging or else used
desktop videoteleconferencing. Most
students have done so, and they are interested in this chapter because it
begins their understanding of the nuts and bolts of how web pages and web site
forms might be transmitted over networks.
War Stories
Electronic
Commerce and Prices
(Objective: illustrate the implications of electronic commerce for
today’s businesses; even though electronic commerce is still fairly new today,
the potential is immense).
A friend of mine recently decided to get a car loan for a new car.
After checking out Edmund’s (www.edmunds.com) for information, he clicked on
the link to a car loan firm. The loan quote was 7.70%. He then called his bank and USAA (a large
financial organization well known for offering cheap loans to
E-mail
I usually describe my first experiences with e-mail, which were
before the days of the Internet. You may also have some good e-mail war
stories. The objective is to reinforce the changes in technologies; the
Internet hasn’t always been dominant. Sometimes
I cite an alternative e-mail technology, the US Veterans Affairs (VA) FORUM,
the VA's national electronic mail system. Electronic discussions, conferences,
distribution of VA directives, news, and computer programs are its primary
functions. FORUM disseminates
information across any communications medium and also hosts several national
databases. Because VA FORUM works according to e-mail threads, it has been
extensively used to document the process of software development in the VA
health care system.
Answers to End-of-Chapter Questions
1.
What
are the different types of application architectures?
Host-based (all processing done
on host system and all data on host with terminals providing access),
client-based (with processing done on client and all data stored on server),
and client-server (balanced processing; usually host provides data access and
storage while the client provides application and presentation logic).
2.
Describe
the four basic functions of an application software package.
Data storage, data access
logic, application logic, and presentation logic.
3.
What
are the advantages and disadvantages of host-based networks versus
client-server networks?
4.
What
is middleware and what does it do?
Middleware manages
client-server message transfer and shields application software from impacts of
hardware changes. Middleware provides
standard communication between products of different vendors through
translation.
5.
Suppose
your organization was contemplating switching from a host-based architecture to
client-server. What problems would you
foresee?
Infrastructure supporting
cabling hardware and software will need to be redesigned to support the client-server
approach to the architecture. Someone would need to be designated to manage
what would now become the local area network, so there may be a personnel
impact. Security would be one area of concern, since processing can be done on
individual workstations. There may be somewhat greater complexity of upgrades,
although newer software is reducing the impact of this kind of problem.
6.
Which
is less expensive: host-based networks or client-server networks? Explain.
Client-server networks are less
expensive because in a competitive market involving multiple vendors, software
and hardware upgrades cost substantially less. Upgrades for host-based networks
are generally very expensive, and occur in what is generally termed a “step
function,” meaning requiring large, discrete steps in expenditure. LANs have the ability to be deployed with a
smoother cost curve in less severe increments.
7.
Compare
and contrast two-tiered, three-tiered, and n-tiered client server
architectures. What are the technical
differences and what advantages and disadvantages do each offer?
Two-tiered architectures have
only clients and servers.
Three-tiered architectures
typical separate (1) presentation logic, (2) application logic, and (3) and
data access logic and storage.
In n-tiered architecture more
than one tier may be used to support application logic, typically due to a Web
server tier being included.
Three-tiered or n-tiered
architectures place a greater load on the network, but balances server load
better and is more scalable.
8.
How
does a thin client differ from a thick client?
Thick clients support all or
most application logic while thin clients support little or no application
logic. Development and maintenance costs for more complex thick-client
environments can be higher than for thin clients.
9.
What
is a network computer?
A network computer supports
Internet access but has no hard disk local storage.
11. For what is HTTP used? What are its
major parts?
The standard
protocol for communication between a Web browser and a Web server is Hypertext
Transfer Protocol (HTTP). An HTTP request from a Web browser to a Web server
has three parts. Only the first part is required; the other two are optional.
The
format of an HTTP response from the server to the browser is very similar to
the browser request. It has three parts, but only the last part is required;
the first two are optional:
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