chapter15 review

Computer Science Illuminated, 3rd Edition

Test Bank for Chapter 15

True / False

1. True or False? A computer network is a collection of connected computing devices that may communicate and share resources.

Answer: True

2. True or False? Computer networks may be connected without the use of physical wires.

Answer: True

3. True or False? Some connections in a network may be made using radio waves or infrared signals.

Answer: True

4. True or False? Only computers can be connected to a computer network.

Answer: False

5. True or False? Printers can be connected directly to a computer network.

Answer: True

6. True or False? A node on a computer network must be a computer.

Answer: False

7. True or False? Data transfer rate is the speed with which data is moved from one place on the network to another.

Answer: True

8. True or False? Bandwidth is a synonym for data transfer rate.

Answer: True

9. True or False? In the client/server model, a user may only access files stored on his/her own computer.

Answer: False

10. True or False? A file server stores and manages files for multiple users on a network.

Answer: True

11. True or False? A local-area network (LAN) connects a small number of nodes in a building or close geographic area.

Answer: True

12. True or False? A network's topology determines how many file servers need to be installed in the network.

Answer: False

13. True or False? A ring topology is a LAN configuration in which a central node controls all message traffic.

Answer: False

14. True or False? A star topology is a LAN configuration in which all nodes are connected in a closed loop.

Answer: False

15. True or False? A bus topology is a LAN configuration in which all nodes share a common line.

Answer: True

16. True or False? Ethernet has become the industry standard for local-area networks.

Answer: True

17. True or False? Ethernet is based on a ring topology.

Answer: False

18. True or False? A wide-area network (WAN) connects two or more local-area networks.

Answer: True

19. True or False? The Internet is a metropolitan-area network (MAN).

Answer: False

20. True or False? An Internet backbone is a company that provides other companies or individuals with access to the Internet.

Answer: False

21. True or False? The Internet backbone is a set of high-capacity, high-speed networks that carry Internet traffic.

Answer: True

22. True or False? An Internet service provider (ISP) is a company that provides other companies or individuals with access to the Internet.

Answer: True

23. True or False? Both DSL and cable connections are broadband connections.

Answer: True

24. True or False? Retrieving data from an Internet resource to your computer is called uploading.

Answer: False

25. True or False? Broadband connections often provide more rapid downloads than uploads.

Answer: True

26. True or False? Messages sent over a shared communication line are divided into fixed-size, numbered pieces called packets.

Answer: True

27. True or False? Network packets contain instructions regarding the route they should travel to reach their destination.

Answer: False

28. True or False? A repeater is a network device that duplicates a packet and sends the duplicate by an alternate route.

Answer: False

29. True or False? In a proprietary system, a commercial vendor opens their technology to other companies.

Answer: False

30. True or False? TCP/IP is the suite of protocols and programs that support low-level network communication.

Answer: True

31. True or False? A file's MIME type indicates the format of files that are attached to email messages.

Answer: True

32. True or False? A firewall is a barrier that protects network equipment from physical damage.

Answer: False

33. True or False? For national security, the U.S. government enforces a national access control policy for Internet traffic.

Answer: False

34. True or False? The IP address of a computer is represented by four numeric values separated by periods (dots).

Answer: True

35. True or False? A hostname uniquely identifies a particular computer among all others on the Internet.

Answer: True

36. True or False? A top-level domain uniquely identifies a particular computer among all others on the Internet.

Answer: False

37. True or False? A top-level domain helps users identify the host's type of organization or country of origin.

Answer: True

38. True or False? Some newer top-level domains include .biz, .name, and .museum.

Answer: True

39. True or False? A domain name server is a computer that attempts to translate a hostname into an IP address.

Answer: True

40. True or False? The domain name system (DNS) uses one large table to map hostnames to IP addresses.

Answer: False

Multiple Choice

41. Which of the following is a device for converting an analog signal to a digital signal and back again?

A. modemB. gatewayC. nodeD. routerE. repeater

Answer: A

42. Which of the following is a computer on a LAN that handles all communication between that network and others?

A. modemB. gatewayC. nodeD. router

E. repeater

Answer: B

43. Which of the following is a generic term used for any device on a network?


Answer: C

44. Which of the following is a network device that directs a packet toward its final destination?


Answer: D

45. Which of the following is a network device that strengthens and propagates a signal along a long communication line?


Answer: E

46. In which of the following LAN configurations do all nodes share a single communication line that carries messages in both directions?

A. bus topologyB. ring topologyC. gateway topologyD. star topologyE. metropolitan topology

Answer: A

47. Which of the following LAN configurations connects all nodes in a closed loop?


Answer: B

48. In which of the following LAN configurations is there a center node to which all others are connected?


Answer: D

49. Which of the following LAN configurations has become a standard for local-area networks?


Answer: A

50. Which of the following describes a set of high-speed networks on the Internet, sponsored by companies such as AT&T and Verizon?

A. backboneB. firewallC. bandwidthD. packet switchingE. hostname

Answer: A

51. Which of the following is the term used to describe a machine and software that protects a network from inappropriate access?


Answer: B

52. Which of the following terms is synonymous with the term data transfer rate?


Answer: C

53. Which of the following describes the process of dividing a message into small pieces and sending those pieces separately to the destination?


Answer: D

54. Which of the following provides a way to uniquely identify a single computer among all others on the Internet?


Answer: E

55. Which of the following is an IP program that can be used to test whether a particular network computer is active and reachable?

A. pingB. telnet

C. portD. TCP/IPE. SMTP

Answer: A

56. Which of the following is a high-level protocol used to log into a computer system from a remote computer?

A. pingB. telnetC. portD. TCP/IPE. SMTP

Answer: B

57. Which of the following is a numeric designation that corresponds to a particular high-level protocol?


Answer: C

58. Which of the following is a suite of protocols and programs that support low-level network communication?


Answer: D

59. Which of the following is a high-level protocol used to specify the transfer of electronic mail?

A. pingB. telnetC. portD. TCP/IP

E. SMTP

Answer: E

60. Which of the following is made up of four decimal numbers separated by dots?

A. IP addressB. domain nameC. top-level domainD. MIME typeE. hostname

Answer: A

61. Which of the following would correspond to an organization, such as a university or company?


Answer: B

62. Which of the following indicates the general type of an organization or a country of origin?


Answer: C

63. Which of the following indicates the format of a file attached to an email message?


Answer: D

64. Which of the following is generally made up of readable words and uniquely identifies a particular computer among all the computers on the Internet?


Answer: E

Fill-in-the-Blank

65. A computer _______________ allows computing devices to communicate and share resources.

Answer: network

66. Devices on a(n) _______________ network often communicate using radio waves or infrared signals.

Answer: wireless

67. A(n) _______________ is a set of rules that defines how data is formatted and processed on a network.

Answer: protocol

68. Data transfer rate is also referred to as _______________.

Answer: bandwidth

69. A(n) _______________ is a computer dedicated to storing and managing files for network users.

Answer: file server

70. A(n) _______________ is a computer dedicated to responding to requests for Web pages.

Answer: web server

71. A(n) _______________ network connects a relatively small number of machines in a close geographical area.

Answer: local-area

72. A(n) _______________ network connects two or more local-area networks over a potentially large geographic area.

Answer: wide-area

73. A(n) _______________ network is a large network that covers a college campus, business campus, or city.

Answer: metropolitan-area

74. A LAN using a(n) _______________ topology connects all nodes in a closed loop on which messages travel in one direction.

Answer: ring

75. A LAN using a(n) _______________ topology uses a central node that controls all message traffic.

Answer: star

76. A LAN using a(n) _______________ topology connects all nodes to a single communication line that carries messages in both directions.

Answer: bus

77. _______________ is an industry standard for local-area networks, based on a bus topology.

Answer: Ethernet

78. A(n) _______________ is a special node on a LAN set up to handle all communication with other networks.

Answer: gateway

79. The Internet _______________ refers to a set of high-capacity, high-speed networks that carry Internet traffic, provided by various companies such as AT&T and Verizon.

Answer: backbone

80. A(n) _______________ is a company that provides other companies or individuals with access to the Internet.

Answer: Internet service provider (ISP)

81. A phone _______________ converts digital data into an analog signal so that it can be transferred over a telephone line.

Answer: modem

82. A(n) _______________ uses phone lines to transfer data digitally.

Answer: digital subscriber line (DSL)

83. In order to connect to the Internet using your home's cable TV lines, you must have a cable _______________.

Answer: modem

84. Both DSL and cable connections are called _______________ connections, indicating data transfer speeds greater than 128K bits per second.

Answer: broadband

85. A message sent over a shared communication line is divided into fixed-size, numbered _______________.

Answer: packets

86. A(n) _______________ is a network device that directs a packet between networks toward its final destination.

Answer: router

87. A(n) _______________ system, in contrast to an open system, uses private technologies controlled by a commercial vendor.

Answer: proprietary

88. The _______________ reference model is a seven-layer breakdown of network interaction used to facilitate communication standards.

Answer: Open Systems Interconnection (OSI)

89. _______________ is a suite of protocols and programs that support low-level network communication.

Answer: TCP/IP

90. An IP program called _______________ is used to test whether a particular network computer is active and reachable.

Answer: ping

91. A(n) _______________ is a numeric designation that corresponds to a particular high-level network protocol.

Answer: port

92. A(n) _______________ is a gateway machine and its software that protects a network from inappropriate access.

Answer: firewall

93. An organization might develop a(n) _______________ that specifies what types of network communication are permitted or denied.

Answer: access control policy

94. matiss.csc.villanova.edu is an example of a(n) _______________ that uniquely identifies one computer among all others on the Internet.

Answer: hostname

95. A(n) _______________, such as 205.39.155.18, is used by network software to designate a particular network resource.

Answer: IP address

96. In the name www.apple.com, apple.com is the _______________.

Answer: domain name

97. .com and .edu are examples of a(n) _______________.

Answer: top-level domain

98. A(n) _______________ is a computer that attempts to translate a hostname into an IP address.

Answer: domain name server

Short Answer

99. What is a protocol in the context of a computer network?

Answer: A set of rules that define how data is formatted and processed on a network.

100. What is network bandwidth?

Answer: Bandwidth is synonymous with data transfer rate, the speed with which data is moved from one node to another on a network.

101. What are the basic roles of the client and server in a client/server model?

Answer: The client sends a request to the server and the server sends a response.

102. What is a file server?

Answer: A computer dedicated to storing and managing files for network users.

103. What is a local-area network?

Answer: A network that connects a relatively small number of machines in a relatively small geographic area, such as a single room or building.

104. Draw a representation of a ring topology.

Answer:

105. Describe communication in a ring topology.

Answer: In a ring topology, messages travel in one direction around the ring; each node sends the message to its neighbor until it reaches its destination.

106. Draw a representation of a star topology.

Answer:

107. Describe communication in a star topology.

Answer: In a star topology, all messages flow into a center node that is responsible for sending it to its destination.

108. Draw a representation of a bus topology.

Answer:

109. Describe communication in a bus topology.

Answer: In a bus topology, messages can travel in either direction along the main communication line and each node ignores any message not intended for it.

110. What is Ethernet?

Answer: The industry standard for local-area networks, based on a bus topology.

111. What is a wide-area network?

Answer: A network that connects two or more local-area networks, usually over a large geographic distance.

112. Describe the Internet.

Answer: The Internet is the ultimate wide-area network that spans the entire planet.

113. What is the function of a gateway computer?

Answer: A gateway computer manages all communication going between its local-area network and other networks.

114. What is a metropolitan-area network (MAN)?

Answer: A MAN is a network infrastructure developed for a smaller area than a WAN, such as a campus or city.

115. What is the Internet backbone?

Answer: A set of high-capacity, high-speed networks that carry Internet traffic, sponsored by various companies such as AT&T and Verizon.

116. What service do Internet service providers (ISP) provide?

Answer: They provide other companies or individuals access to the Internet.

117. What does a phone modem do?

Answer: It converts digital data into an analog signal for transfer over a phone line and vice versa.

118. What is a digital subscriber line (DSL)?

Answer: An Internet connection that uses a regular phone line to transfer a digital signal.

119. What is a cable modem?

Answer: A device that allows computer network communication using the cable TV line in a home.

120. Which Internet connections provide broadband data transfer?

Answer: Both DSL connections and cable modems are broadband connections.

121. What is packet switching?

Answer: The process of dividing a message into fixed-size, numbered sections for transfer over a shared communication line, which are then reassembled into the original message at the destination.

122. What is a router?

Answer: A network device that directs a packet toward its destination.

123. What is a repeater?

Answer: A device that strengthens and propagates a signal along a long communication line.

124. What is a proprietary system?

Answer: A system that uses private technologies controlled by a commercial vendor.

125. Define interoperability.

Answer: The ability of software and hardware on multiple machines and from multiple commercial vendors to communicate.

126. What is the Open Systems Interconnection (OSI) Reference Model?

Answer: A seven-layer logical breakdown of network interaction used to facilitate communication standards.

127. List the seven layers of the OSI Reference Model from top to bottom.

Answer: Application layer, presentation layer, session layer, transport layer, network layer, data link layer, and the physical layer.

128. What is TCP/IP?

Answer: A suite of protocols and software that support low-level network communication.

129. What is SMTP?

Answer: A protocol used to specify the transfer of electronic mail (it stands for Simple Mail Tranfer Protocol).

130. What is FTP?

Answer: A protocol for transferring files from one network computer to another (it stands for File Transfer Protocol).

131. What is Telnet?

Answer: A protocol used to log into a computer system from a remote computer.

132. What is HTTP

Answer: A protocol that defines the exchange of documents on the Web (it stands for Hypertext Transfer Protocol).

133. What is a port?

Answer: A numeric designation (such as 21) that corresponds to a particular high-level protocol (such as FTP).

134. What is a MIME type used for?

Answer: They indicate the format of a file that is attached to an email message.

135. Give an example of a hostname.

Answer: matisse.csc.villanova.edu

136. Discuss the pieces of the hostname matisse.csc.villanova.edu.

Answer: Matisse is the name of a computer in the csc.villanova.edu subdomain of the villanova.edu domain; the edu top-level domain indicates that it is an educational organization.

137. Give an example of an IP address.

Answer: 148.78.250.12

138. What is a top-level domain?

Answer: The last section of a domain name, specifying the type of organization or its country of origin.

139. Give three examples of top-level domains other than .com and .edu.

Answer: .org, .gov, .biz, .name, .net (or several others)

140. Give an example of a top-level domain that specifies a country code.

Answer: .ca for Canada, .uk for the United Kingdom (or several others)

141. What is the domain name system (DNS)?

Answer: A distributed system for resolving hostnames.

142. What is a domain name server?

Answer: A computer that attempts to translate a hostname into an IP address.

Essay

143. Describe the client/server model and its relationship to computer networks. Give examples.

Answer: The client/server model is a generic approach to network communication in which one party, the client, makes a request of another party, the server, which responds to the request. A file server, for instance, is a dedicated network computer that stores files that users on the network (the clients) can request. A web server is a computer that hosts web pages. When a browser (the client) requests a web page, the web server delivers it.

144. Compare the ring, star, and bus LAN topologies. Include a visual representation of each.

Answer: A ring topology, shown first below, connects all nodes in a closed loop. Messages in a ring topology travel in only one direction. In a star topology, shown second, all messages go through a center node that has the responsibility of directing all messages to their destination. A bus topology, show last, connects all nodes to a single shared communication line, in which messages travel in both directions.

145. Compare and contrast the three primary techniques for accessing the

Internet.

Answer: A phone modem uses a dial-up connection, a normal phone line, and an analog signal. One audio frequency is used to represent binary 0 and another for binary 1. A digital subscriber line (DSL) uses a normal phone line, but a digital signal. Since audio and data are transmitted using different frequencies, both can occur at the same time. The third option is the uses the cable TV line and a cable modem. A small portion of the frequencies a cable line can carry are used for data communication. Both DSL and cable connections are broadband, with significantly higher speeds than using a phone modem.

146. Describe how a message is transmitted using packet switching.

Answer: A message (such as an email message) is divided up into fixed-size, numbered sections called packets. Each packet is sent to its destination, where the message is reassembled. The packets may travel different routes to the destination, and may arrive out of order. Using packet switching improves the efficiency and fairness of network traffic.

147. Describe how networks are divided into classes.

Answer: There are three network classes: class A, class B, and class C. Class A networks are very large with many nodes, so in the IP address one byte is assigned for the network address and three bytes are assigned for the host number. Class C networks are small with few nodes, but there a large number of them, so three bytes are used for the network number and one byte is used for the host number. Class B network fall in the middle, so two bytes are used for the network number and two bytes are used for the host number.

148. Discuss an organization's use of an access control policy and its implementation.

Answer: A business or other organization may create an access control policy to formally establish the types of network communication that are permitted. The rules may also be expressed in terms of which types of communication are denied. For example, an organization may permit email communication, but deny web use. Or it may deny access to certain web sites. An access control policy is enforced using a firewall, which is a gateway machine and software that allows only certain types of network communication to be conducted on its network.

149. Describe the Domain Name System (DNS) and how it is used to resolve network addresses.

Answer: When using a web browser or an email address, humans use readable hostnames to designate network destinations. Internally, network software uses numeric IP addresses instead of hostnames. DNS is used to translate, or resolve, a hostname to its corresponding IP address. It is a distributed system, with multiple name servers on the Internet that can attempt to resolve a name. If a particular name server cannot resolve a name, it propagates the request to another name server. Eventually the name gets resolved or the request times out.

150. Discuss some of the privacy issues related to employees in the workplace.

Answer: Often employees have a false sense of privacy in the workplace. Employers have put more and more surveillance technology in place, up 50% since 1997. Programs can be used to record every keystroke a user enters on the computer. Phone calls are routinely monitored and recorded. Video cameras keep track of the workplace environment. Email traffic is often monitored.

Employers argue that these activities are simply smart business, protecting themselves against workplace misbehavior of various kinds. Privacy advocates say the trend has gone too far down the road toward Big Brother.

chapter15 review

Documents