Chapter 1: Introduction 1
Chapter 2: Network Models 4
Chapter 3: Signals 7
Chapter 4: Encoding and Modulation 12
Chapter 5: Multiplexing 16
Chapter 6: Switching 21
Chapter 7: Transmission Media 23
Chapter 8 : Telephone, Cable, and Satellite Networks 28
Chapter 9 : Flow and Error Control 31
Chapter 10 : Access Method 35
Chapter 11 : Wired Local Area Networks 39
Chapter 12 : Wireless Local Area Networks 42



Chapter 1: Introduction

1. In a _______ connection, more than two devices can share a single link.

a. Point-to-point
b. Primary
c. Multipoint
d. Secondary
answer (c): Multipoint

2. Communication between a computer and a keyboard involves ______________ transmission
a. Full-duplex
b. Half-duplex
c. Simplex
d. Automatic
answer (c): Simplex

3. In a network with 25 computers, which topology would require the most extensive cabling?
a. Star
b. Mesh
c. Bus
d. Ring
answer (b): Mesh

4. Which topology requires a central controller or hub?
a. Star
b. Mesh
c. Bus
d. Ring
answer (a): Star

5. The _______ is the physical path over which a message travels.
a. Protocol
b. Medium
c. Signal
d. All of the above
answer (b): Medium

6. Which organization has authority over interstate and international commerce in the communications field?
a. ITU-T
b. IEEE
c. ISO
d. FCC
answer (d): FCC

7. The information to be communicated in a data communications system is the ________
a. Medium
b. Protocol
c. Transmission
d. Message
answer (d): Message

8. Frequency of failure and network recovery time after a failure are measures of the _______ of a network.
a. Performance
b. Security
c. Reliability
d. Feasibility
answer (c): Reliability

9. In _______ transmission, the channel capacity is shared by both communicating devices at all times.
a. Full-duplex
b. Simplex
c. Half-duplex
d. Half-Simplex
answer (a): Full-duplex

10. An unauthorized user is a network _______ issue.
a. Performance
b. Reliability
c. Security
d. All of the above
answer (c): Security

11. Which topology requires a multipoint connection?
a. Mesh
b. Star
c. Ring
d. Bus
answer (d): Bus

12. A television broadcast is an example of _______ transmission.
a. Half-duplex
b. Full-duplex
c. Simplex
d. Automatic
answer (c): Simplex

13. A _______ connection provides a dedicated link between two devices.
a. Multipoint
b. Point-to-Point
c. Primary
d. Secondary
answer (b): Point-to-Point

14. A cable break in a _______ topology stops all transmission.
a. Mesh
b. Star
c. Primary
d. Bus
answer (d): Bus


Chapter 2: Network Models


15. The _______ layer changes bits into electromagnetic signals.
a. Physical
b. Transport
c. None of the above
d. Data link
answer (a): Physical

16. The physical layer is concerned with the transmission of _______ over the physical medium.
a. Programs
b. Protocols
c. Bits
d. Dialogs
The correct answer is c

17. Mail services are available to network users through the _______ layer.
a. Data link
b. Physical
c. Application
d. Transport
The correct answer is c

18. As the data packet moves from the lower to the upper layers, headers are _______.
a. Added
b. Rearranged
c. Modified
d. Subtracted
The correct answer is d
Your answer is b

19. As the data packet moves from the upper to the lower layers, headers are _______.
a. Removed
b. Added
c. Rearranged
d. Modified
The correct answer is b

20. The _______ layer lies between the network layer and the application layer.
a. Data link
b. Physical
c. Transport
d. None of the above
The correct answer is c

21. Layer 2 lies between the physical layer and the _______ layer.
a. Data link
b. Network
c. Transport
d. None of the above
The correct answer is b
Your answer is b

22. When data are transmitted from device A to device B, the header from A's layer 4 is read by B's _______ layer.
a. Application
b. Physical
c. Transport
d. None of the above
The correct answer is c
Your answer is a

23. Which layer functions as a liaison between user support layers and network support layers?
a. Network layer
b. Transport layer
c. Physical layer
d. Application layer
The correct answer is b

24. What is the main function of the transport layer?
a. Process-to-process delivery
b. Node-to-node delivery
c. Synchronization
d. Updating and maintenance of routing tables
The correct answer is a

25. Which of the following is an application layer service?
a. Remote log-in
b. File transfer and access
c. Mail service
d. All the above
The correct answer is d

26. The Internet model consists of _______ layers.
a. Three
b. Five
c. Seven
d. Eight
The correct answer is b

27. The process-to-process delivery of the entire message is the responsibility of the _______ layer.
a. Physical
b. Network
c. Transport
d. Application
The correct answer is c

28. The _______ layer is the layer closest to the transmission medium.
a. Network
b. Physical
c. Data link
d. Transport
The correct answer is b


Chapter 3: Signals


29. Before data can be transmitted, they must be transformed to ________.
a. Electromagnetic signals
b. Periodic signals
c. Aperiodic signals
d. Low-frequency sine waves
The correct answer is a

30. When one of the components of a signal has a frequency of zero, the average amplitude of the signal ________.
a. Is less than zero
b. Is greater than zero
c. Is zero
d. (a) or (b)
The correct answer is b

31. A periodic signal can always be decomposed into ________.
a. Exactly an odd number of sine waves
b. A set of sine waves, one of which must have a phase of 0
c. A set of sine waves
d. None of the above
The correct answer is c

32. A periodic signal completes one cycle in 0.001 s. What is the frequency?
a. 1 Hz
b. 100 Hz
c. 1 KHz
d. 1 MHz
The correct answer is c

33. In a frequency-domain plot, the horizontal axis measures the ________.
a. Frequency
b. Peak amplitude
c. Phase
d. Slope
The correct answer is a

34. In a time-domain plot, the vertical axis is a measure of ________.
a. Frequency
b. Phase
c. Amplitude
d. Time
The correct answer is c

35. In a time-domain plot, the horizontal axis is a measure of ________.
a. Signal amplitude
b. Time
c. Frequency
d. Phase
The correct answer is b

36. If the bandwidth of a signal is 5 KHz and the lowest frequency is 52 KHz, what is the highest frequency?
a. 5 KHz
b. 10 KHz
c. 47 KHz
d. 57 KHz
The correct answer is d

37.
Your answer is a

38. What is the bandwidth of a signal that ranges from 40 KHz to 4 MHz?
a. 3.96 MHz
b. 36 MHz
c. 360 KHz
d. 396 KHz
The correct answer is a

39. As frequency increases, the period ________.
a. Decreases
b. Increases
c. Remains the same
d. Doubles
The correct answer is a

40. When propagation speed is multiplied by propagation time, we get the ________.
a. Throughput
b. Wavelength of the signal
c. Distance a signal or bit has traveled
d. Distortion factor
The correct answer is c

41. Propagation time is ________ proportional to distance and ________ proportional to propagation speed.
a. Inversely; directly
b. Inversely; inversely
c. Directly; inversely
d. Directly; directly
The correct answer is c

42. Wavelength is ________ proportional to propagation speed and ________ proportional to period.
a. Directly; directly
b. Inversely; directly
c. Directly; inversely
d. Inversely; inversely
The correct answer is a

43. Which of the following can be determined from a frequency-domain graph of a signal?
a. Phase
b. Power
c. Frequency
d. All the above
The correct answer is c

44. Which of the following can be determined from a frequency-domain graph of a signal?
a. Phase
b. Bandwidth
c. Power
d. All the above
The correct answer is b

45. In a frequency-domain plot, the vertical axis measures the ________.
a. Frequency
b. Peak amplitude
c. Phase
d. Slope
The correct answer is b

46. Given two sine waves A and B, if the frequency of A is twice that of B, then the period of B is ________ that of A.
a. One-half
b. Twice
c. The same as
d. Indeterminate from
The correct answer is b

47. The wavelength of green light in air is ________ the wavelength of green light in fiber-optic cable.
a. Greater than
b. Less than
c. Equal to
d. None of the above
The correct answer is b

48. Using the Shannon formula to calculate the data rate for a given channel, if C = B, then ________.
a. The signal is equal to the noise
b. The signal is less than the noise
c. The signal is greater than the noise
d. Not enough information is given to answer the question
The correct answer is a

49. A sine wave is ________.
a. Aperiodic and continuous
b. Periodic and discrete
c. Aperiodic and discrete
d. Periodic and continuous
The correct answer is d

50. If the maximum amplitude of a sine wave is 2 V, the minimum amplitude is ________ V.
a. 2
b. 1
c. -2
d. Between -2 and 2
The correct answer is c

51. A signal is measured at two different points. The power is P1 at the first point and P2 at the second point. The dB is 0. This means ________.
a. P2 is zero
b. P2 equals P1
c. P2 is much larger than P1
d. P2 is much smaller than P1
The correct answer is b

52. ________ is a type of transmission impairment in which the signal loses strength due to the resistance of the transmission medium.
a. Distortion
b. Noise
c. Decibel
d. Attenuation
The correct answer is d

53. ________ is a type of transmission impairment in which the signal loses strength due to the different propagation speeds of each frequency that makes up the signal.
a. Attenuation
b. Noise
c. Distortion
d. Decibel
The correct answer is c

54. ________ is a type of transmission impairment in which an outside source such as crosstalk corrupts a signal.
a. Attenuation
b. Noise
c. Distortion
d. Decibel
The correct answer is b

55.
The ________ has units of meters/second or kilometers/second.
a. Throughput
b. Propagation time
c. Propagation speed
d. (b) and (c)
The correct answer is c

56. ________ has units of bits/second.
a. Throughput
b. Propagation speed
c. Propagation time
d. (b) and (c)
The correct answer is a

57. The ________ has units of seconds.
a. Throughput
b. Propagation time
c. Propagation speed
d. (a) and (b)
The correct answer is b

58.
The wavelength of a signal depends on the ________.
a. Frequencies of the signal
b. Medium
c. Phase of the signal
d. (a) and (b)
The correct answer is d


Chapter 4: Encoding and Modulation

59. Which encoding technique attempts to solve the loss of synchronization due to long strings of 0s?
a. NRZ
b. BnZS
c. AMI
d. (a) and (b)
The correct answer is b

60. Block coding can help in _______ at the receiver.
a. Synchronization
b. Error detection
c. Attenuation
d. (a) and (b)
The correct answer is d

61. In _______ transmission, bits are transmitted simultaneously, each across its own wire.
a. Parallel
b. Asynchronous serial
c. Synchronous serial
d. (a) and (b)
The correct answer is a

62. Unipolar, bipolar, and polar encoding are types of _______ encoding.
a. Block
b. Line
c. NRZ
d. Manchester
The correct answer is b

63. _______ encoding has a transition at the middle of each bit.
a. RZ
b. Manchester
c. Differential Manchester
d. All the above
The correct answer is d

64. _______ encoding has a transition at the beginning of each 0 bit.
a. Differential Manchester
b. RZ
c. Manchester
d. All the above
The correct answer is a

65. PCM is an example of _______ conversion.
a. Analog-to-analog
b. Analog-to-digital
c. Digital-to-digital
d. Digital-to-analog
The correct answer is b

66. If the frequency spectrum of a signal has a bandwidth of 500 Hz with the highest frequency at 600 Hz, what should be the sampling rate, according to the Nyquist theorem?
a. 500 samples/s
b. 1000 samples/s
c. 200 samples/s
d. 1200 samples/s
The correct answer is d

67. One factor in the accuracy of a reconstructed PCM signal is the _______.
a. Number of bits used for quantization
b. Signal bandwidth
c. Carrier frequency
d. Baud rate
The correct answer is a

68. In asynchronous transmission, the gap time between bytes is _______.
a. Fixed
b. A function of the data rate
c. Variable
d. Zero
The correct answer is c

69. Synchronous transmission does not have _______.
a. A start bit
b. A stop bit
c. Gaps between bytes
d. All the above
The correct answer is d

70. Which encoding type always has a nonzero average amplitude?
a. Polar
b. Bipolar
c. Unipolar
d. All the above
The correct answer is c

71. Which of the following encoding methods does not provide for synchronization?
a. Manchester
b. NRZ-L
c. RZ
d. NRZ-I
The correct answer is b

72. Which encoding method uses alternating positive and negative values for 1s?
a. Manchester
b. AMI
c. NRZ-I
d. RZ
The correct answer is b

73. In PCM, an analog-to- _______ conversion occurs.
a. Analog
b. Digital
c. QAM
d. Differential
The correct answer is b

74. If the maximum value of a PCM signal is 31 and the minimum value is -31, how many bits were used for coding?
a. 4
b. 5
c. 6
d. 7
The correct answer is c

75. RZ encoding involves _______ signal levels.
a. Five
b. Four
c. Three
d. Two
The correct answer is c

76. Which quantization level results in a more faithful reproduction of the signal?
a. 2
b. 8
c. 16
d. 32
The correct answer is d

77. In _______ transmission, bits are transmitted over a single wire, one at a time.
a. Asynchronous serial
b. Synchronous serial
c. Parallel
d. (a) and (b)
The correct answer is d

78. In _______ transmission, a start bit and a stop bit frame a character byte.
a. Synchronous serial
b. Asynchronous serial
c. Parallel
d. (a) and (b)
The correct answer is b

79. If a symbol is composed of 3 bits, there are _______ data levels.
a. 2
b. 4
c. 8
d. 16
The correct answer is c

80. The Nyquist theorem specifies the minimum sampling rate to be_______.
a. Twice the bandwidth of a signal
b. Twice the highest frequency of a signal
c. Equal to the lowest frequency of a signal
d. Equal to the highest frequency of a signal
The correct answer is b

81. Pulse rate is always _______ the bit rate.
a. Less than
b. Less than or equal to
c. Greater than
d. Greater than or equal to
The correct answer is b


Chapter 5: Multiplexing

82. AM and FM are examples of ________ modulation.
a. Analog-to-analog
b. Analog-to-digital
c. Digital-to-digital
d. Digital-to-analog
The correct answer is a
Your answer is a

83. In QAM, both phase and ________ of a carrier frequency are varied.
a. Frequency
b. Bit rate
c. Amplitude
d. Baud rate
The correct answer is c

84. Which of the following is most affected by noise?
a. PSK
b. FSK
c. QAM
d. ASK
The correct answer is d

85. ASK, PSK, FSK, and QAM are examples of ________ modulation.
a. Analog-to-analog
b. Analog-to-digital
c. Digital-to-digital
d. Digital-to-analog
The correct answer is d

86. If the baud rate is 400 for a 4-PSK signal, the bit rate is ________ bps.
a. 1600 100
b. 800
c. 400
d. 100
The correct answer is b

87. If the bit rate for an ASK signal is 1200 bps, the baud rate is ________.
a. 300
b. 400
c. 600
d. 1200
The correct answer is d

88. As the bit rate of an FSK signal increases, the bandwidth ________.
a. Remains the same
b. Decreases
c. Increases
d. Doubles
The correct answer is c

89. In 16-QAM, there are 16 ________.
a. Phases
b. Combinations of phase and amplitude
c. Amplitudes
d. bps
The correct answer is b

90. Which modulation technique involves tribits, eight different phase shifts, and one amplitude?
a. FSK
b. ASK
c. 4-PSK
d. 8-PSK
The correct answer is d

91. If the bit rate for an FSK signal is 1200 bps, the baud rate is ________.
a. 300
b. 400
c. 600
d. 1200
The correct answer is d

92. If the bit rate for a QAM signal is 3000 bps and a signal unit is represented by a tribit, what is the baud rate?
a. 300
b. 400
c. 1000
d. 1200
The correct answer is c

93. If the baud rate for a QAM signal is 3000 and a signal unit is represented by a tribit, what is the bit rate?
a. 300
b. 400
c. 1000
d. 9000
The correct answer is d

94. If the baud rate for a QAM signal is 1800 and the bit rate is 9000, how many bits are there per signal unit?
a. 3
b. 4
c. 5
d. 6
The correct answer is c

95. Given an AM radio signal with a bandwidth of 10 KHz and the highest-frequency component at 705 KHz, what is the frequency of the carrier signal?
a. 705 KHz
b. 700 KHz
c. 710 KHz
d. Cannot be determined from given information
The correct answer is b

96. A modulated signal is formed by ________.
a. Changing the carrier wave by the modulating signal
b. Quantization of the source data
c. Changing the modulating signal by the carrier wave
d. Sampling at the Nyquist frequency
The correct answer is a

97. If FCC regulations are followed, the carrier frequencies of adjacent AM radio stations are ________ apart.
a. 5 KHz
b. 10 KHz
c. 200 KHz
d. 530 KHz
The correct answer is b

98. If FCC regulations are followed, ________ potential FM stations are theoretically possible in a given area.
a. 50
b. 100
c. 133
d. 150
The correct answer is a

99. When an ASK signal is decomposed, the result is ________.
a. An infinite number of sine waves
b. Always one sine wave
c. Always two sine waves
d. None of the above
The correct answer is a

100. The bandwidth of an FM signal requires 10 times the bandwidth of the _______ signal.
a. Bipolar
b. Sampling
c. Carrier
d. Modulating
The correct answer is d

101. Modulation of an analog signal can be accomplished through changing the ________ of the carrier signal.
a. Amplitude
b. Frequency
c. Phase
d. Any of the above
The correct answer is d

102. For a telephone line, the bandwidth for voice is usually _______ the bandwidth for data.
a. Less than
b. Greater than
c. Twice
d. Equivalent to
The correct answer is b

103. For a given bit rate, the minimum bandwidth for ASK is ________ the minimum bandwidth for FSK.
a. Less than
b. Equivalent to
c. Greater than
d. Twice
The correct answer is a

104. What is the object of trellis coding?
a. To narrow the bandwidth
b. To increase the data rate
c. To reduce the error rate
d. To simplify modulation
The correct answer is c

105. A modulator converts a(n)________ signal to a(n) ________ signal.
a. Digital; analog
b. Analog; digital
c. PSK; FSK
d. FSK; PSK
The correct answer is a

106. A 56K modem can download at a rate of _______ Kbps and upload at a rate of ________ Kbps.
a. 56.6; 33.6
b. 56.6; 56.6
c. 33.6; 33.6
d. 33.6; 56.6
The correct answer is a

107. For FSK, as the difference between the two carrier frequencies increases, the bandwidth ________.
a. Remains the same
b. Decreases
c. Increases
d. Halves
The correct answer is c

108. The bit rate always equals the baud rate in which type of signal?
a. FSK
b. QAM
c. 4-PSK
d. All the above
The correct answer is a

109. Which ITU-T modem standard uses trellis coding?
a. V.32
b. V.33
c. V.34
d. (a) and (b)
The correct answer is a

110. In trellis coding the number of data bits is ________ the number of transmitted bits.

a. Less than
b. More than
c. Equal to
d. Double that of
The correct answer is a


Chapter 6: Switching
111. Which multiplexing technique transmits digital signals?
a. WDM
b. FDM
c. TDM
d. None of the above
The correct answer is c

112. Which multiplexing technique shifts each signal to a different carrier frequency?
a. TDM
b. FDM
c. Both (a) and (b)
d. None of the above
The correct answer is b

113. In TDM, for n signal sources of the same data rate, each frame contains _______ slots.
a. 0 to n
b. n
c. n + 1
d. n - 1
The correct answer is b

114. In TDM, the transmission rate of the multiplexed path is usually _______ the sum of the transmission rates of the signal sources.
a. 1 less than
b. Greater than
c. Less than
d. Equal to
The correct answer is b

115. DS-1 through DS-4 are _______ while T-1 through T-4 are _______.
a. Services; signals
b. Services; lines
c. Services; multiplexers
d. Multiplexers; signals
The correct answer is b

116. The sharing of a medium and its link by two or more devices is called _______.
a. Modulation
b. Encoding
c. Multiplexing
d. Line discipline
The correct answer is c

117. In AT&T's FDM hierarchy, the bandwidth of each group type can be found by multiplying _______ and adding extra bandwidth for guard bands.
a. The sampling rate by 4000 Hz
b. The number of voice channels by 4000 Hz
c. The number of voice channels by 8 bits/sample
d. The sampling rate by 8 bits/sample
The correct answer is b

118. Guard bands increase the bandwidth for _______.
a. TDM
b. FDM
c. Both (a) and (b)
d. None of the above
The correct answer is b

119. Which multiplexing technique transmits analog signals?
a. FDM
b. TDM
c. WDM
d. (a) and (c)
The correct answer is d

120. In a T-1 line, _______ interleaving occurs.
a. Bit
b. Byte
c. DS-0
d. Switch
The correct answer is b

121. Which multiplexing technique involves signals composed of light beams?
a. WDM
b. FDM
c. TDM
d. None of the above
The correct answer is a


Chapter 7: Transmission Media
122. The VLF and LF bands use _______ propagation for communications.
a. Space
b. Ground
c. Sky
d. Line of sight
The correct answer is b

123. Category 1 UTP cable is most often used in _______ networks.
a. Infrared
b. Telephone
c. Fast Ethernet
d. Traditional Ethernet
The correct answer is b

124. BNC connectors are used by _______ cables.
a. Fiber-optic
b. UTP
c. STP
d. Coaxial
The correct answer is d

125. Which of the following is not a guided medium?
a. Twisted-pair cable
b. Fiber-optic cable
c. Atmosphere
d. Coaxial cable
The correct answer is c

126. In an environment with many high-voltage devices, the best transmission medium would be _________.
a. Twisted-pair cable
b. Coaxial cable
c. The atmosphere
d. Optical fiber
The correct answer is d

127. _______ cable consists of an inner copper core and a second conducting outer sheath.
a. Coaxial
b. Twisted-pair
c. Fiber-optic
d. Shielded twisted-pair
The correct answer is a

128. In fiber optics, the signal source is _______ waves.
a. Very low-frequency
b. Light
c. Radio
d. Infrared
The correct answer is b

129. Smoke signals are an example of communication through _______.
a. A guided medium
b. A refractive medium
c. An unguided medium
d. A small or large medium
The correct answer is c

130. Which of the following primarily uses guided media?
a. Cellular telephone system
b. Satellite communications
c. Local telephone system
d. Radio broadcasting
The correct answer is c

131. What is the major factor that makes coaxial cable less susceptible to noise than twisted-pair cable?
a. Outer conductor
b. Inner conductor
c. Diameter of cable
d. Insulating material
The correct answer is a

132. The RG number gives us information about _______.
a. Optical fibers
b. Twisted pairs
c. Coaxial cables
d. All the above
The correct answer is c

133. Transmission media are usually categorized as _______.
a. Guided or unguided
b. Fixed or unfixed
c. Determinate or indeterminate
d. Metallic or nonmetallic
The correct answer is a

134. The _______ is an association that sponsors the use of infrared waves.
a. EIA
b. IrDA
c. FCC
d. PUD
The correct answer is b

135. In an optical fiber, the inner core is _______ the cladding.
a. Less dense than
b. Denser than
c. The same density as
d. Another name for
The correct answer is b

136. The inner core of an optical fiber is _______ in composition.
a. Copper
b. Bimetallic
c. Glass or plastic
d. Liquid
The correct answer is c

137. When a beam of light travels through media of two different densities, if the angle of incidence is greater than the critical angle, _______ occurs.
a. Refraction
b. Reflection
c. Incidence
d. Criticism
The correct answer is b

138. In _______ propagation, the beam of propagated light is almost horizontal, and the low-density core has a small diameter compared to the cores of the other propagation modes.
a. Single-mode
b. Multimode step-index
c. Multimode graded-index
d. Multimode single-index
The correct answer is a

139. _______ is the propagation method subject to the greatest distortion.
a. Single-mode
b. Multimode step-index
c. Multimode graded-index
d. Multimode single-index
The correct answer is b

140. In _______ propagation, the core is of varying densities.
a. Single-mode
b. Multimode step-index
c. Multimode graded-index
d. Multimode single-index
The correct answer is c

141. When we talk about unguided media, usually we are referring to _______.
a. Metallic wires
b. Nonmetallic wires
c. The air
d. None of the above
The correct answer is c

142. Transmission media are closest to the _______ layer.
a. Application
b. Physical
c. Network
d. Transport
The correct answer is b

143. Radio wave and microwave frequencies range from _______.
a. 3 to 300 KHz
b. 300 KHz to 3 GHz
c. 3 KHz to 300 GHz
d. 3 KHz to 3000 GHz
The correct answer is c

144. Optical fibers, unlike wire media, are highly resistant to _______.
a. High-frequency transmission
b. Low-frequency transmission
c. Refraction
d. Electromagnetic interference
The correct answer is d

145. In _______ propagation, low-frequency radio waves hug the earth.
a. Space
b. Ground
c. Sky
d. Line of sight
The correct answer is b

146. When the angle of incidence is _______ the critical angle, the light beam bends along the interface.
a. More than
b. Less than
c. Equal to
d. None of the above
The correct answer is c

147. A parabolic dish antenna is a(n) _______ antenna.
a. Omnidirectional
b. Bidirectional
c. Horn
d. Unidirectional
The correct answer is d


Chapter 8 : Telephone, Cable, and Satellite Networks
148. The telephone service handled between two LATAs is called _______.
a. An ILEC
b. An IXC
c. A CLEC
d. A POP
The correct answer is b

149. How many crosspoints are needed in a single-stage switch with 40 inputs and 50 outputs?
a. 2000
b. 90
c. 50
d. 40
The correct answer is a

150. The _______ is a device that connects n inputs to m outputs.
a. Crossbar
b. Crosspoint
c. Modem
d. RAM
The correct answer is a

151. The established telephone company that provided services in a LATA before 1966 and owns the cabling system is called _______.
a. A CLEC
b. An IXC
c. An ILEC
d. A POP
The correct answer is c

152. In a crossbar with 1000 crosspoints, approximately how many are in use at any time?
a. 100
b. 250
c. 500
d. 1000
The correct answer is b

153. The _______ of a TSI controls the order of delivery of slot values that are stored in RAM.
a. Crossbar
b. Crosspoint
c. Transceiver
d. Control unit
The correct answer is d

154. Which of the following is a time-division switch?
a. TSI
b. TDM bus
c. Crosspoint
d. (a) and (b)
The correct answer is d

155. In a time-division switch, a _______ governs the destination of a packet stored in RAM.
a. Control unit
b. TDM bus
c. Crosspoint
d. Crossbar
The correct answer is a

156. A telephone network is an example of a _______ network.
a. Circuit-switched
b. Packet-switched
c. Message-switched
d. None of the above
The correct answer is a

157. The local loop has _______ cable that connects the subscriber telephone to the nearest end office.
a. Coaxial
b. Fiber-optic
c. Twisted-pair
d. (b) and (c)
The correct answer is c

158. Trunks are transmission media such as _______ that handle the telephone communication between offices.
a. Twisted-pair cable
b. Fiber-optic cable
c. Satellite links
d. (b) and (c)
The correct answer is d

159. A new telephone company that provides services in a LATA after 1966 is called _______.
a. An ILEC
b. An IXC
c. A POP
d. A CLEC
The correct answer is d

160. If the end office receives two bursts of analog signals with frequencies of 697 and 1477 Hz, then the number _______ has been punched.
a. 1
b. 2
c. 3
d. 4
The correct answer is c

161. In _______ circuit switching, delivery of data is delayed because data must be stored and retrieved from RAM.
a. Time-division
b. Space-division
c. Virtual
d. Packet
The correct answer is a

162. Data from a computer are _______; the local loop handles _______ signals.
a. Digital; digital
b. Digital; analog
c. Analog; analog
d. Analog; digital
The correct answer is b

163. To create a _______, combine crossbar switches in stages.
a. TSI
b. Multistage switch
c. Crosspoint
d. Packet switch
The correct answer is b

164. A traditional telephone line has a bandwidth of _______.
a. 2000 Hz
b. 4000 Hz
c. 2000 MHz
d. 4000 MHz
The correct answer is b


Chapter 9 : Flow and Error Control
165. SONET is a standard for _______ networks.
a. Twisted-pair cable
b. Fiber-optic cable
c. Coaxial cable
d. Ethernet
The correct answer is b

166. _______ limit the bandwidth of the local loop to 4 KHz.
a. Fiber nodes
b. Repeaters
c. Filters
d. Hubs
The correct answer is c

167. The actual bit rate of ADSL downstream data is _______.
a. 6 to 30 Kbps
b. 64 Kbps to 1 Mbps
c. 500 Kbps to 8 Mbps
d. 31 Kbps to 255 Mbps
The correct answer is c

168. _______ is a device at the telephone company site that can packetize data to be sent to the ISP server.
a. A filter
b. A splitter
c. A DSLAM
d. An ADSL modem
The correct answer is c

169. The standard for data transmission over an HFC network is called _______.
a. DOCSIS
b. CMTS
c. MCNS
d. ADSL
The correct answer is a

170. DMT is a modulation technique that combines elements of _______ and _______.
a. FDM; TDM
b. QDM; QAM
c. PSK; FSK
d. FDM; QAM
The correct answer is d

171. The _______ is an HFC network device installed inside the distribution hub that receives data from the Internet and passes them to the combiner.
a. DOCSIS
b. MCNS
c. CM
d. CMTS
The correct answer is d

172. HDSL encodes data using _______.
a. 6B/8T
b. 4B/5B
c. 2B1Q
d. 1B2Q
The correct answer is c
Your answer is a

173. _______ encoded signal is more susceptible to attenuation than _______ encoded signal.
a. An AMI; a 2B1Q
b. An AMI; a 2B2Q
c. A 2B1Q; an AMI
d. None of the above
The correct answer is a

174. Another name for the cable TV office is the _______.
a. Fiber node
b. Combiner
c. Head end
d. Splitter
The correct answer is c

175. A traditional cable TV network transmits signals ______.
a. Upstream and downstream
b. Upstream
c. Downstream
d. None of the above
The correct answer is c

176. _______ was designed as an alternative to the T-1 line.
a. VDSL
b. SDSL
c. HDSL
d. ADSL
The correct answer is c

177. The synchronous payload envelope of an STS-1 frame contains _______.
a. Pointers
b. User data
c. Overhead
d. (b) and (c)
The correct answer is d

178. _______ has a higher transmission rate in the downstream direction than in the upstream direction.
a. VDSL
b. ADSL
c. SDSL
d. (a) and (b)
The correct answer is d

179. An HFC network uses _______ as the medium from the switch to the fiber node.
a. UTP
b. STP
c. Optical fiber
d. Coaxial cable
The correct answer is c

180. In an HFC network, the distribution hub handles the _______ of signals.
a. Modulation
b. Distribution
c. Splitting
d. (a) and (b)
The correct answer is d

181. A TV channel in an HFC network needs a _______-MHz bandwidth.
a. 369
b. 6
c. 100
d. 250
The correct answer is b

182. _______ data go from the subscriber to the Internet.
a. Downstream
b. Upstream
c. Midstream
d. None of the above
The correct answer is b

183. In an HFC network, the upstream data are modulated using the _______ modulation technique.
a. PCM
b. QAM
c. QPSK
d. ASK
The correct answer is b

184. _______ is suitable for businesses that require comparable upstream and downstream data rates.
a. SDSL
b. VDSL
c. ADSL
d. (a) and (b)
The correct answer is a

185. SONET is an acronym for _______ Network.
a. Standard Optical
b. Symmetric Open
c. Synchronous Optical
d. Standard Open
The correct answer is c

186. The largest portion of the bandwidth for ADSL carries _______.
a. Voice communication
b. Downstream data
c. Upstream data
d. Control data
The correct answer is b

187. In a SONET system, _______ can remove signals from a path.
a. An add/drop multiplexer
b. A repeater
c. An STS multiplier
d. A regenerator
The correct answer is a


Chapter 10 : Access Method
188. Which of the following best describes a single-bit error?
a. A single bit is inverted.
b. A single bit is inverted per transmission.
c. A single bit is inverted per data unit.
d. Any of the above
The correct answer is c

189. Which error detection method uses ones complement arithmetic?
a. Simple parity check
b. Checksum
c. Two-dimensional parity check
d. CRC
The correct answer is b

190. Which error detection method consists of just one redundant bit per data unit?
a. Two-dimensional parity check
b. CRC
c. Simple parity check
d. Checksum
The correct answer is c

191. Which error detection method involves polynomials?
a. CRC
b. Simple parity check
c. Two-dimensional parity check
d. Checksum
The correct answer is a

192. If the ASCII character G is sent and the character D is received, what type of error is this?
a. Single-bit
b. Multiple-bit
c. Burst
d. Recoverable
The correct answer is c

193. If the ASCII character H is sent and the character I is received, what type of error is this?
a. Burst
b. Recoverable
c. Single-bit
d. Multiple-bit
The correct answer is c

194. In cyclic redundancy checking, what is the CRC?
a. The remainder
b. The divisor
c. The quotient
d. The dividend
The correct answer is a

195. Which error detection method involves the use of parity bits?
a. Simple parity check
b. Two-dimensional parity check
c. CRC
d. (a) and (b)
The correct answer is d

196. In cyclic redundancy checking, the divisor is _______ the CRC.
a. The same size as
b. 1 bit more than
c. 1 bit less than
d. 2 bits more than
The correct answer is b

197. If the data unit is 111111, the divisor 1010, and the remainder 110, what is the dividend at the receiver?
a. 111111011
b. 1010110
c. 111111110
d. 110111111
The correct answer is c

198. Which error detection method consists of a parity bit for each data unit as well as an entire data unit of parity bits?
a. Simple parity check
b. Checksum
c. Two-dimensional parity check
d. CRC
The correct answer is c

199. If the data unit is 111111 and the divisor 1010, what is the dividend at the transmitter?
a. 1111110000
b. 111111000
c. 111111
d. 1111111010
The correct answer is b

200. If odd parity is used for ASCII error detection, the number of 0s per 8-bit symbol is _______.
a. Indeterminate
b. 42
c. Even
d. Odd
The correct answer is d

201. In CRC there is no error if the remainder at the receiver is _______.
a. Nonzero
b. The quotient at the sender
c. Equal to the remainder at the sender
d. Zero
The correct answer is d

202. At the CRC generator, _______ added to the data unit after the division process.
a. 0s are
b. 1s are
c. The CRC remainder is
d. The polynomial is
The correct answer is c

203. The sum of the checksum and data at the receiver is _______ if there are no errors.
a. -0
b. +0
c. The complement of the checksum
d. The complement of the data
The correct answer is a

204. In CRC the quotient at the sender _______.
a. Becomes the dividend at the receiver
b. Becomes the divisor at the receiver
c. Is the remainder
d. Is discarded
The correct answer is d

205. The Hamming code is a method of _______.
a. Error detection
b. Error correction
c. Error encapsulation
d. (a) and (b)
The correct answer is d

206. At the CRC checker, _______ means that the data unit is damaged.
a. A string of alternating 1s and 0s
b. A nonzero remainder
c. A string of 0s
d. A string of 1s
The correct answer is b

207. Which error detection method can detect a single-bit error?
a. Simple parity check
b. Two-dimensional parity check
c. CRC
d. All the above
The correct answer is d

208. Which error detection method can detect a burst error?
a. The parity check
b. Two-dimensional parity check
c. CRC
d. (b) and (c)
The correct answer is d

209. At the CRC generator, _______ added to the data unit before the division process.
a. A polynomial is
b. A CRC remainder is
c. 0s are
d. 1s are
The correct answer is c


Chapter 11 : Wired Local Area Networks
210. HDLC is an acronym for _______.
a. High-duplex line communication
b. Half-duplex digital link combination
c. High-level data link control
d. Host double-level circuit
The correct answer is c

211. Flow control is needed to prevent ________.
a. Overflow of the sender buffer
b. Overflow of the receiver buffer
c. Bit errors
d. Collision between sender and receiver
The correct answer is b

212. In a Go-Back-N ARQ, if the window size is 63, what is the range of sequence numbers?
a. 1 to 63
b. 1 to 64
c. 0 to 63
d. 0 to 64
The correct answer is c

213. For a sliding window of size n - 1 (n sequence numbers), there can be a maximum of _______ frames sent but unacknowledged.
a. 0
b. n
c. n - 1
d. n + 1
The correct answer is b

214. When data and acknowledgment are sent on the same frame, this is called _______.
a. Backpacking
b. Piggypacking
c. Piggybacking
d. A good idea
The correct answer is c

215. In _______ ARQ, if a NAK is received, only the specific damaged or lost frame is retransmitted.
a. Go-Back-N
b. Stop-and-Wait
c. Selective Repeat
d. (a) and (b)
The correct answer is a

216. ARQ stands for _______.
a. Automatic repeat request
b. Automatic retransmission request
c. Acknowledge repeat request
d. Automatic repeat quantization
The correct answer is a

217. In Go-Back-N ARQ, if frames 4, 5, and 6 are received successfully, the receiver may send an ACK _______ to the sender.
a. 5
b. 6
c. 7
d. Any of the above
The correct answer is d

218. The shortest frame in HDLC protocol is usually the _______ frame.
a. Information
b. Management
c. Supervisory
d. None of the above
The correct answer is c

219. The address field of a frame in HDLC protocol contains the address of the _______ station.
a. Primary
b. Secondary
c. Tertiary
d. (a) or (b)
The correct answer is b

220. The HDLC _______ field defines the beginning and end of a frame.
a. Address
b. Control
c. Flag
d. FCS
The correct answer is c

221. A timer is set when _______ is (are) sent out.
a. An ACK
b. A NAK
c. A data frame
d. All the above
The correct answer is c

222. For Stop-and-Wait ARQ, for n data packets sent, _______ acknowledgments are needed.
a. n - 1
b. n + 1
c. n
d. 2n
The correct answer is c

223. What is present in all HDLC control fields?
a. N(R)
b. N(S)
c. Code bits
d. P/F bit
The correct answer is d


Chapter 12 : Wireless Local Area Networks
224. According to the PPP transition state diagram, options are negotiated in the _______ state.
a. Networking
b. Terminating
c. Establishing
d. Authenticating
The correct answer is c

225. According to the PPP transition state diagram, verification of user identification occurs in the _______ state.
a. Networking
b. Terminating
c. Establishing
d. Authenticating
The correct answer is d

226. PAP requires _______ and _______ from the user.
a. A password; a calculated value
b. Authentication identification; a calculated value
c. Authentication identification; a password
d. A challenge value; a password
The correct answer is c

227. According to the PPP transition state diagram, the link is disconnected in the _______ state.
a. Networking
b. Terminating
c. Establishing
d. Authenticating
The correct answer is b

228. In the PPP frame, the _______ field defines the contents of the data field.
a. FCS
b. Flag
c. Control
d. Protocol
The correct answer is d

229. According to the PPP transition state diagram, exchange of user control and data packets occurs in the _______ state.
a. Networking
b. Terminating
c. Establishing
d. Authenticating
The correct answer is a

230. _______, an (a)_______ protocol, establishes and terminates a network layer connection for IP packets.
a. CHAP; NCP
b. IPCP; NCP
c. NCP; IPCP
d. SLIP; PPP
The correct answer is b

231. In the PPP frame, the _______ field is similar to that of the U-frame in HDLC.
a. Flag
b. Protocol
c. FCS
d. Control
The correct answer is d

232. In the PPP frame, the _______ field has a value of 11111111 to indicate the broadcast address of HDLC.
a. Protocol
b. Address
c. Control
d. FCS
The correct answer is b

233. What is the purpose of LCP packets?
a. Configuration
b. Termination
c. Option negotiation
d. All the above
The correct answer is d

234. _______ is a three-way handshake for user verification.
a. PPP
b. CHAP
c. PAP
d. (b) and (c)
The correct answer is b

235. A PAP packet and a CHAP packet can be distinguished by the value of the _______ field of the PPP frame.
a. Protocol
b. FCS
c. Address
d. Control
The correct answer is d

236. In the PPP frame, the _______ field is for error control.
a. FCS
b. Flag
c. Control
d. Protocol
The correct answer is a

237. CHAP authentication, the user takes the system's _______ and its own _______ to create a result that is then sent to the system.
a. Authentication identification; password
b. Password; authentication identification
c. Challenge value; password
d. Password; challenge value
The correct answer is c

238. If an FDMA network has eight stations, the medium bandwidth has ______ bands.
a. 1
b. 2
c. 8
d. 16
The correct answer is c

239. In the _______ random-access method there is no collision.
a. CSMA/CD
b. CSMA/CA
c. ALOHA
d. Token-passing
The correct answer is b

240. In the 1-persistent approach, when a station finds an idle line, it _______.
a. Sends immediately
b. Waits 0.1 s before sending
c. Waits 1 s before sending
d. Waits a time equal to 1 - p before sending
The correct answer is a

241. _______ requires one primary station and one or more secondary stations.
a. Token ring
b. Reservation
c. Polling
d. CSMA
The correct answer is c

242. In the p-persistent approach, when a station finds an idle line, it _______.
a. Sends immediately
b. Waits 1 s before sending
c. Sends with probability 1 - p
d. Sends with probability p
The correct answer is d

243. A network using the CSMA random-access method with p equal to 0.25 will send _______ percent of the time after accessing an idle line.
a. 50
b. 75
c. 100
d. 25
The correct answer is d

244. The 1-persistent approach can be considered a special case of the p-persistent approach with p equal to _______.
a. 1.0
b. 2.0
c. 0.1
d. 0.5
The correct answer is a

245. _______ is a random-access protocol.
a. FDMA
b. CDMA
c. MA
d. Polling
The correct answer is c

246. In the reservation access method, if there are 10 stations on a network, then there are _______ reservation minislots in the reservation frame.
a. 10
b. 11
c. 5
d. 9
The correct answer is a

247. A Walsh table for 16 stations has a chip sequence of _______ chips.
a. 16
b. 32
c. 4
d. 8
The correct answer is a

248. _______ is a controlled-access protocol.
a. FDMA
b. TDMA
c. CSMA
d. Reservation
The correct answer is d

249. _______ is (are) a channelization protocol.
a. FDMA
b. TDMA
c. CDMA
d. All the above
The correct answer is d

250. _______ is the access protocol used by traditional Ethernet.
a. Token ring
b. CSMA
c. CSMA/CD
d. CSMA/CA
The correct answer is c

251. The most primitive random access method is _______.
a. Channelization
b. ALOHA
c. CSMA
d. Token passing
The correct answer is b

252. When a collision is detected in a network using CSMA/CD, _______.
a. The frame is immediately resent
b. The backoff value is decremented by 1
c. A jam signal is sent by the station
d. The backoff value is set to 0
The correct answer is c

253. In the _______ random-access method, stations do not sense the medium.
a. CSMA/CA
b. ALOHA
c. CSMA/CD
d. Ethernet
The correct answer is b

254. When a primary device asks a secondary device if it has data to send, this is called _______.
a. Backing off
b. Polling
c. Selecting
d. Reserving
The correct answer is b

255. If a TDMA network has eight stations, the medium bandwidth has _______ bands.
a. 1
b. 2
c. 8
d. 16
The correct answer is a

256. If a CDMA network has eight stations, the medium bandwidth has _______ bands.
a. 1
b. 2
c. 8
d. 16
The correct answer is a

257. If an Ethernet destination address is 08-07-06-05-44-33, then this is a ______ address.
a. Broadcast
b. Unicast
c. Multicast
d. Any of the above
The correct answer is b

258. What is the hexadecimal equivalent of the Ethernet address 01011010 00010001 01010101 00011000 10101010 00001111?
a. 5A-11-55-18-AA-0F
b. 5A-88-AA-18-55-F0
c. 5A-81-BA-81-AA-0F
d. 5A-18-5A-18-55-0F
The correct answer is a

259. Which of the following could not be an Ethernet source address?
a. 8A-7B-6C-DE-10-00
b. 8B-32-21-21-4D-34
c. EE-AA-C1-23-45-32
d. 46-56-21-1A-DE-F4
The correct answer is b

260. What is the efficiency of 4B/5B block encoding?
a. 60 percent
b. 80 percent
c. 20 percent
d. 40 percent
The correct answer is b

261. Which of the following could not be an Ethernet unicast destination?
a. 44-AA-C1-23-45-32
b. 46-56-21-1A-DE-F4
c. 48-32-21-21-4D-34
d. 43-7B-6C-DE-10-00
The correct answer is d

262. What is the efficiency of 8B/10B encoding?
a. 80 percent
b. 20 percent
c. 40 percent
d. 60 percent
The correct answer is a

263. A 10-station Ethernet LAN uses a _______-port bridge if the effective average data rate for each station is 2 Mbps.
a. 10
b. 1
c. 2
d. 5
The correct answer is d

264. A _______-station Ethernet LAN uses a four-port bridge. Each station has an effective average data rate of 1.25 Mbps.
a. 160
b. 80
c. 40
d. 32
The correct answer is d

265. An 80-station traditional Ethernet is divided into four collision domains. This means that a maximum of _______ stations contend for medium access at any one time.
a. 20
b. 76
c. 80
d. 320
The correct answer is a

266. If an Ethernet destination address is 07-01-02-03-04-05, then this is a ______ address.
a. Unicast
b. Broadcast
c. Multicast
d. Any of the above
The correct answer is c

267. What is the efficiency of a frame in half-duplex Gigabit Ethernet carrying 46 bytes of data?
a. 97 percent
b. 70 percent
c. 56 percent
d. 12 percent
The correct answer is b

268. Which of the following could not be an Ethernet multicast destination?
a. B7-7B-6C-DE-10-00
b. 7C-56-21-1A-DE-F4
c. 7B-AA-C1-23-45-32
d. 83-32-21-21-4D-34
The correct answer is b

269. Which of the following is a four-wire Gigabit Ethernet implementation?
a. 1000Base-SX
b. 1000Base-LX
c. 1000Base-T
d. 1000Base-CX
The correct answer is c

270. Forty stations are on an Ethernet LAN. A 10-port bridge segments the LAN. What is the effective average data rate of each station?
a. 1.0 Mbps
b. 2.5 Mbps
c. 2.0 Mbps
d. 5.0 Mbps
The correct answer is b

271. A wireless LAN using FHSS hops 10 times per cycle. If the bandwidth of the original signal is 10 MHz and 2 GHz is the lowest frequency, the highest frequency of the system is _______ GHz.
a. 1.0
b. 2.0
c. 2.1
d. 3.0
The correct answer is c

272. An FHSS wireless LAN has a spread spectrum of 1 GHz. The bandwidth of the original signal is 250 MHz, and there are ______ hops per cycle.
a. 4
b. 3
c. 2
d. 1
The correct answer is a

273. A wireless LAN using FHSS hops 10 times per cycle. If the bandwidth of the original signal is 10 MHz, the spread spectrum is _______ MHz.
a. 1000
b. 10,000
c. 10
d. 100
The correct answer is d

274. A wireless LAN using DSSS with an 8-bit chip code needs _______ MHz for sending data that originally required a 10-MHz bandwidth.
a. 20
b. 80
c. 2
d. 8
The correct answer is b

275. A wireless LAN using DSSS with _______-bit chip code needs 320 MHz for sending data that originally required a 20-MHz bandwidth.
a. A 2
b. A 16
c. A 32
d. An 8
The correct answer is b

276. A wireless LAN using DSSS with a 4-bit chip code needs 10 MHz for sending data that originally required a _______-MHz bandwidth.
a. 20
b. 25
c. 40
d. 2.5
The correct answer is d

277. In an ESS the _______ station is not mobile.
a. BSS
b. AP
c. Server
d. None of the above
The correct answer is b

278. In an ESS the _______ stations are part of a wired LAN.
a. BSS
b. AP
c. Server
d. All the above
The correct answer is b

279. A station with _______ mobility is either stationary or moving only inside a BSS.
a. No-transition
b. BSS
c. ESS
d. (a) and (b)
The correct answer is a

280. _______ combine to form a scatternet.
a. APs
b. Piconets
c. BSSs
d. ESSs
The correct answer is b

281. Bluetooth uses _______ in the physical layer.
a. DSSS
b. DHSS
c. FHSS
d. OFDM
The correct answer is c

282. A _______ frame usually precedes a CTS frame.
a. SIFS
b. RTS
c. DIFS
d. Any of the above
The correct answer is b

283. A station with _______ mobility can move from one BSS to another.
a. No-transition
b. ESS-transition
c. BSS-transition
d. (b) and (c)
The correct answer is c

284. A station with _______ mobility can move from one ESS to another.
a. No-transition
b. ESS-transition
c. BSS-transition
d. (b) and (c)
The correct answer is b

285. A _______ frame usually precedes an RTS frame.
a. DIFS
b. CIFS
c. CTS
d. None of the above
The correct answer is d

286. Wireless transmission is _______ prone to error than/as wired transmission.
a. Less
b. More
c. Half as
d. None of the above
The correct answer is b

287. Which MAC sublayer does IEEE 802.11 define?
a. LLC
b. PCF
c. DCF
d. (b) and (c)
The correct answer is d

288. What is the basic access method for wireless LANs as defined by IEEE 802.11?
a. LLC
b. PCF
c. DCF
d. BFD
The correct answer is c

289. The access method for wireless LANs as defined by IEEE 802.11 is based on ______.
a. Token passing
b. CSMA
c. CSMA/CD
d. CSMA/CA
The correct answer is d

290. FHSS, DSSS, and OFDM are _______ layer specifications.
a. Data link
b. Network
c. Physical
d. Transport
The correct answer is c

291. Stations do not sense the medium during _______ time.
a. SIFS
b. NAV
c. RTS
d. CTS
The correct answer is b

292. A Bluetooth frame needs _______ s for hopping and control mechanisms.
a. 3
b. 625
c. 259
d. A multiple of 259
The correct answer is c

293. In the ______ method, the sender hops from frequency to frequency in a specific order.
a. DSSS
b. FHSS
c. OFDM
d. HR-DSSS
The correct answer is b

294. A wireless LAN uses _______ frames for acknowledgment.
a. Management
b. Data
c. Control
d. None of the above
The correct answer is c

295. A wireless LAN uses _______ frames for the initial communication between stations and the access points.
a. Control
b. Data
c. Management
d. None of the above
The correct answer is c

296. A Bluetooth network can have _______ master(s).
a. One
b. Two
c. Three
d. Eight
The correct answer is a

297. A bridge forwards or filters a frame by comparing the information in its address table to the frame's _______.
a. Source node's physical address
b. Layer 2 destination address
c. Layer 2 source address
d. Layer 3 destination address
The correct answer is b

298. Repeaters function in the _______ layer(s).
a. Network
b. Physical (MAC)
c. Data link
d. (a) and (b)
The correct answer is b

299. A _______ is actually a multiport repeater.
a. Hub
b. Bridge
c. Router
d. VLAN
The correct answer is a

300. A repeater takes a weakened or corrupted signal and _______ it.
a. Resamples
b. Reroutes
c. Amplifies
d. Regenerates
The correct answer is d

301. A bridge has access to the _______ address of a station on the same network.
a. Network
b. Service access point
c. Physical (MAC)
d. All the above
The correct answer is c

302. The bridge with the least-cost path between the LAN and the root bridge is called the _______ bridge.
a. Forwarding
b. Designated
c. Blocking
d. (a) and (b)
The correct answer is b

303. A system with redundant bridges might have a problem with _______ in the system.
a. Filters
b. Spanning trees
c. Loops
d. All the above
The correct answer is c

304. Bridges function in the _______ layer(s).
a. Physical (MAC)
b. Data link
c. Network
d. (a) and (b)
The correct answer is d

305. In a VLAN, stations are separated into groups by _______.
a. Software methods
b. Location
c. Physical methods
d. Switches
The correct answer is a

306. A bridge can _______.
a. Filter a frame
b. Forward a frame
c. Extend a LAN
d. Do all the above
The correct answer is d

307. A _______ bridge has the smallest ID.
a. Designated
b. Forwarding
c. Blocking
d. Root
The correct answer is d

308. A bridge never forwards frames out of the _______ port.
a. Root
b. Designated
c. Blocking
d. Forwarding
The correct answer is c

309. Which type of bridge builds and updates its tables from address information on frames?
a. Transparent
b. Simple
c. (a) and (b)
d. None of the above
The correct answer is a

310. VLAN technology divides a LAN into ______ groups.
a. Multiplexed
b. Framed
c. Physical
d. Logical
The correct answer is d

311. Which of the following is a connecting device?
a. Bridge
b. Repeater
c. Hub
d. All the above
The correct answer is d

312. Which station characteristic can be used to group stations into a VLAN?
a. Port numbers
b. MAC addresses
c. IP addresses
d. All the above
The correct answer is d

313. _______ is a first-generation cellular phone system.
a. GSM
b. IS-95
c. AMPS
d. D-AMPS
The correct answer is c

314. AMPS uses _______ for modulation.
a. FM
b. FSK
c. PM
d. (a) and (b)
The correct answer is d

315. _______ separates the AMPS voice channels.
a. CDMA
b. TDMA
c. FDMA
d. (b) and (c)
The correct answer is c

316. _______ is a cellular telephone system popular in Europe.
a. GSM
b. D-AMPS
c. IS-95
d. AMPS
The correct answer is a

317. D-AMPS uses _______ for multiplexing.
a. CDMA
b. TDMA
c. FDMA
d. (b) and (c)
The correct answer is d

318. GSM uses _______ for multiplexing.
a. CDMA
b. TDMA
c. FDMA
d. (b) and (c)
The correct answer is d

319. DSSS is used by the _______ cellular phone system.
a. AMPS
b. IS-95
c. D-AMPS
d. GSM
The correct answer is b

320. _______ base stations use GPS for synchronization.
a. GSM
b. IS-95
c. AMPS
d. D-AMPS
The correct answer is b

321. _______ will have 288 satellites in 12 polar orbits.
a. Teledesic
b. Globalstar
c. Iridium
d. GPS
The correct answer is a

322. IS-95 has a frequency reuse factor of _______.
a. 7
b. 95
c. 1
d. 5
The correct answer is c

323. The path that a satellite makes around the world is called _______.
a. An orbit
b. A period
c. A footprint
d. An uplink
The correct answer is a

324. A GEO satellite has _______ orbit.
a. A polar
b. An inclined
c. An equilateral
d. An equatorial
The correct answer is d

325. Which orbit has the highest altitude?
a. LEO
b. GEO
c. MEO
d. HEO
The correct answer is b

326. _______ is a second-generation cellular phone system.
a. D-AMPS
b. GSM
c. IS-95
d. All the above
The correct answer is d

327. A _______ is a computerized center that is responsible for connecting calls, recording call information, and billing.
a. Cell
b. Mobile station
c. Base station
d. Mobile switching center
The correct answer is d

328. _______ has 48 satellites in six polar orbits.
a. Iridium
b. Teledesic
c. Globalstar
d. GPS
The correct answer is c

329. The signal from a satellite is aimed at a specific area called the _______.
a. Orbit
b. Period
c. Footprint
d. Uplink
The correct answer is c

330. In _______, a mobile station always communicates with just one base station.
a. Roaming
b. A roaming handoff
c. A hard handoff
d. A soft handoff
The correct answer is c

331. MEO satellites orbit _______ Van Allen belts.
a. In the
b. Above both
c. Below both
d. Between the
The correct answer is d

332. _______ is often used for navigation purposes.
a. GPS
b. AMPS
c. IS-95
d. Iridium
The correct answer is a

333. An LEO satellite has _______ orbit.
a. An equatorial
b. A polar
c. An inclined
d. All the above
The correct answer is b

334. Teledesic is a _______ LEO satellite system.
a. Passband
b. Broadband
c. Little
d. Big
The correct answer is b

335. _______ has 66 satellites in six LEOs.
a. Globalstar
b. Teledesic
c. GPS
d. Iridium
The correct answer is d

336. Transmission from the Earth to the satellite is called the _______.
a. Downlink
b. Uplink
c. Footlink
d. Up print
The correct answer is b

337. The _______ is not used for voice communication.
a. GPS
b. Iridium system
c. IS-95 system
d. Globalstar system
The correct answer is a

338. _______ is a Frame Relay option that transmits voice through the network.
a. LMI
b. FRAD
c. VOFR
d. DLCI
The correct answer is c

339. Frame Relay provides _______ connections.
a. PVC
b. SVC
c. (a) and (b)
d. None of the above
The correct answer is c

340. Routing and switching in Frame Relay are performed by the _______ layer.
a. Physical
b. Network
c. Data link
d. (b) and (c)
The correct answer is c

341. Frame Relay is unsuitable for ________ due to possible delays in transmission resulting from variable frame sizes.
a. File transfers
b. Real-time video
c. Fixed-rate data communication
d. All the above
The correct answer is b

342. The Frame Relay address field is _______ in length.
a. 4 bytes
b. 2 bytes
c. 3 bytes
d. Any of the above
The correct answer is d

343. Because ATM _______, which means that cells follow the same path, the cells do not usually arrive out of order.
a. Is asynchronous
b. Uses virtual circuit routing
c. Is multiplexed
d. Is a network
The correct answer is b

344. _______ is a protocol to control and manage interfaces in Frame Relay networks.
a. FRAD
b. DLCI
c. LMI
d. VOFR
The correct answer is c

345. Frame Relay operates in the _______.
a. Physical and data link layers
b. Physical, data link, and network layers
c. Physical layer
d. Data link layer
The correct answer is a

346. In the data link layer, Frame Relay uses _______.
a. A simplified HDLC protocol
b. LAPB
c. BSC protocol
d. Any ANSI standard protocol
The correct answer is a

347. The VPI of an NNI is _______ bits in length.
a. 16
b. 8
c. 12
d. 24
The correct answer is c

348. In data communications, ATM is an acronym for _______.
a. Automated Teller Machine
b. Automatic Transmission Model
c. Asynchronous Transfer Mode
d. Asynchronous Telecommunication Method
The correct answer is c

349. Which AAL type is designed to support SEAL?
a. AAL1
b. AAL2
c. AAL3/4
d. AAL5
The correct answer is d

350. Which layer in ATM protocol reformats the data received from other networks?
a. Physical
b. Application adaptation
c. Data adaptation
d. ATM
The correct answer is b

351. Which layer in ATM protocol has a 53-byte cell as an end product?
a. ATM
b. Application adaptation
c. Physical
d. Cell transformation
The correct answer is a

352. Which AAL type is designed to support a data stream that has a constant bit rate?
a. AAL1
b. AAL2
c. AAL3/4
d. AAL5
The correct answer is a

353. The VPI of a UNI is _______ bits in length.
a. 12
b. 16
c. 24
d. 8
The correct answer is d

354. In an ATM network, all cells belonging to a single message follow the same _______ and remain in their original order until they reach their destination.
a. Virtual circuit
b. Transmission path
c. Virtual path
d. None of the above
The correct answer is a

355. A device called a(n) _______ allows frames from an ATM network to be transmitted across a Frame Relay network.
a. FRAD
b. LMI
c. VOFR
d. DLCI
The correct answer is a

356. A _______ provides a connection or a set of connections between switches.
a. Transmission path
b. Virtual circuit
c. Virtual path
d. None of the above
The correct answer is b

357. A _________ is the physical connection between an endpoint and a switch or between two switches.
a. Virtual path
b. Transmission path
c. Virtual circuit
d. None of the above
The correct answer is b

358. On a network that uses NAT, the _______ has a translation table.
a. Router
b. Switch
c. Server
d. None of the above
The correct answer is a

359. Identify the class of IP address 229.1.2.3.
a. Class A
b. Class B
c. Class C
d. Class D
The correct answer is d

360. On a network that uses NAT, _______ initiates the communication.
a. An internal host
b. An external host
c. The router
d. (a) or (b)
The correct answer is a

361. A subnet mask in class B can have _______ 1s with the remaining bits 0s.
a. Nine
b. Seventeen
c. Three
d. Fourteen
The correct answer is b

362. A subnet mask in class C can have _______ 1s with the remaining bits 0s.
a. Twenty-five
b. Twelve
c. Seven
d. Ten
The correct answer is a

363. Identify the class of IP address 4.5.6.7.
a. Class A
b. Class B
c. Class C
d. Class D
The correct answer is a

364. Identify the class of IP address 191.1.2.3.
a. Class A
b. Class B
c. Class C
d. Class D
The correct answer is b

365. A subnet mask in class A can have _______ 1s with the remaining bits 0s.
a. Nine
b. Four
c. Thirty-three
d. Three
The correct answer is a

366. Class _______ has the greatest number of hosts per given network address.
a. A
b. B
c. C
d. D
The correct answer is a

367. A subnet mask in class B has nineteen 1s. How many subnets does it define?
a. 128
b. 8
c. 32
d. 64
The correct answer is b

368. In _______ routing, the full IP address of a destination is given in the routing table.
a. Next-hop
b. Host-specific
c. Network-specific
d. Default
The correct answer is b

369. A subnet mask in class C has twenty-five 1s. How many subnets does it define?
a. 0
b. 2
c. 8
d. 16
The correct answer is b

370. Given the IP address 180.25.21.172 and the subnet mask 255.255.192.0, what is the subnet address?
a. 180.25.21.0
b. 180.25.8.0
c. 180.25.0.0
d. 180.0.0.0
The correct answer is c

371. Given the IP address 18.250.31.14 and the subnet mask 255.240.0.0, what is the subnet address?
a. 18.9.0.14
b. 18.0.0.14
c. 18.31.0.14
d. 18.240.0.0
The correct answer is d

372. _______ is a client-server program that provides an IP address, subnet mask, IP address of a router, and IP address of a name server to a computer.
a. NAT
b. DHCP
c. CIDR
d. ISP
The correct answer is b

373. In _______, each packet of a message need not follow the same path from sender to receiver.
a. The virtual approach to packet switching
b. The datagram approach to packet switching
c. Message switching
d. None of the above
The correct answer is b

374. An IP address consists of _______ bits.
a. 8
b. 32
c. 4
d. Any of the above
The correct answer is b

375. On a network that uses NAT, the router can use _______ global address(es).
a. A pool of
b. One
c. Two
d. None of the above
The correct answer is a

376. In _______ routing, the mask and destination addresses are both 0.0.0.0 in the routing table.
a. Default
b. Next-hop
c. Network-specific
d. Host-specific
The correct answer is a

377. A subnet mask in class A has fourteen 1s. How many subnets does it define?
a. 64
b. 128
c. 32
d. 8
The correct answer is a

378. In which type of switching do all the packets of a message follow the same channels of a path?
a. Virtual circuit packet switching
b. Message switching
c. Datagram packet switching
d. None of the above
The correct answer is a

379. In _______ routing, the destination address is a network address in the routing table.
a. Network-specific
b. Host-specific
c. Next-hop
d. Default
The correct answer is a

380. Given the IP address 201.14.78.65 and the subnet mask 255.255.255.224, what is the subnet address?
a. 201.14.78.64
b. 201.14.78.32
c. 201.14.78.65
d. 201.14.78.12
The correct answer is a

381. In error reporting the encapsulated ICMP packet goes to _______.
a. The receiver
b. A router
c. The sender
d. Any of the above
The correct answer is c

382. When the hop-count field reaches zero and the destination has not been reached, a _______ error message is sent.
a. Destination-unreachable
b. Redirection
c. Time-exceeded
d. Parameter-problem
The correct answer is c

383. An ARP request is _______ to _______.
a. Multicast; one host
b. Unicast; all hosts
c. Broadcast; all hosts
d. Unicast; one host
The correct answer is c

384. What is the maximum size of the data portion of the IP datagram?
a. 65,515 bytes
b. 65,535 bytes
c. 65,475 bytes
d. 65,460 bytes
The correct answer is a

385. A best-effort delivery service such as IP does not include _______.
a. Error correction
b. Error checking
c. Datagram acknowledgment
d. All the above
The correct answer is d

386. An HLEN value of decimal 10 means _______.
a. There is 10 bytes of options
b. There is 40 bytes in the header
c. There is 40 bytes of options
d. There is 10 bytes in the header
The correct answer is b

387. In IPv4, what is the value of the total length field in bytes if the header is 28 bytes and the data field is 400 bytes?
a. 407
b. 107
c. 428
d. 427
The correct answer is c

388. If the fragment offset has a value of 100, it means that _______.
a. The first byte of the datagram is byte 800
b. The datagram has not been fragmented
c. The datagram is 100 bytes in size
d. The first byte of the datagram is byte 100
The correct answer is a

389. What is needed to determine the number of the last byte of a fragment?
a. Identification number
b. Offset number
c. Total length
d. (b) and (c)
The correct answer is d

390. The IP header size _______.
a. Depends on the MTU
b. Is 20 to 60 bytes long
c. Is 20 bytes long
d. Is 60 bytes long
The correct answer is b

391. If a host needs to synchronize its clock with another host, it sends a _______ message.
a. Time-exceeded
b. Time-stamp-request
c. Source-quench
d. Router-advertisement
The correct answer is b

392. Which of the following is a necessary part of the IPv6 datagram?
a. Base header
b. Extension header
c. Data packet from the upper layer
d. (a) and (c)
The correct answer is d

393. _______ is a dynamic mapping protocol in which a physical address is found for a given IP address.
a. RARP
b. ICMP
c. ARP
d. None of the above
The correct answer is c

394. A router reads the _______ address on a packet to determine the next hop.
a. MAC
b. Source
c. IP
d. ARP
The correct answer is c

395. The target hardware address on an Ethernet is _______ in an ARP request.
a. Variable
b. Class-dependent
c. 0x000000000000
d. 0.0.0.0
The correct answer is c

396. When not all fragments of a message have been received within the designated amount of time, a _______ error message is sent.
a. Time-exceeded
b. Parameter-problem
c. Source-quench
d. Time-stamp-request
The correct answer is a

397. A ______ can learn about network ______ by sending out a router-solicitation packet.
a. Router; routers
b. Router; hosts
c. Host; routers
d. Host; hosts
The correct answer is c

398. Which of the following types of ICMP messages needs to be encapsulated into an IP datagram?
a. Time-exceeded
b. Multicasting
c. Echo reply
d. All the above
The correct answer is d

399. The purpose of echo request and echo reply is to _______.
a. Report errors
b. Check packet lifetime
c. Check node-to-node communication
d. Find IP addresses
The correct answer is c

400. An ARP reply is _______ to _______.
a. Unicast; one host
b. Broadcast; all hosts
c. Multicast; one host
d. Unicast; all hosts
The correct answer is a

401. One method to alert a source host of congestion is the _______ message.
a. Source-quench
b. Redirection
c. Echo-request
d. Destination-unreachable
The correct answer is a

402. A time-exceeded message is generated if _______.
a. The round-trip time between hosts is close to zero
b. The time-to-live field has a zero value
c. Fragments of a message do not arrive within a set time
d. (b) and (c)
The correct answer is d

403. To determine whether a node is reachable, _______ message can be sent.
a. An echo-request
b. An echo-reply
c. A redirection
d. A source-quench
The correct answer is a

404. In IPv6, the _______ field in the base header restricts the lifetime of a datagram.
a. Version
b. Hop limit
c. Priority
d. Next-header
The correct answer is b

405. In IPv4, what is the length of the data field given an HLEN value of 12 and total length value of 40,000?
a. 39,952
b. 39,988
c. 40,012
d. 40,048
The correct answer is a

406. A datagram is fragmented into three smaller datagrams. Which of the following is true?
a. The do not fragment bit is set to 1 for all three datagrams.
b. The identification field is the same for all three datagrams.
c. The more fragment bit is set to 0 for all three datagrams.
d. The offset field is the same for all three datagrams.
The correct answer is b

407. Errors in the header or option fields of an IP datagram require a ______ error message.
a. Source-quench
b. Parameter-problem
c. Router-solicitation
d. Redirection
The correct answer is b

408. The cost field of a router's first table from itself always has a value of _______.

a. Some positive integer
b. 0
c. 1
d. Infinity
The correct answer is b

409. A routing table contains _______.
a. The destination network ID
b. The hop count to reach the network
c. The router ID of the next hop
d. All the above
The correct answer is d

410. Router B receives an update from router A that indicates Net1 is two hops away. The next update from A says Net1 is five hops away. What value is entered in B's routing table for Net1? Assume the basic RIP is being used.
a. 6
b. 7
c. 2
d. 3
The correct answer is a

411. If the routing table contains four new entries, how many update messages must the router send to its one neighbor router?
a. 3
b. 4
c. 1
d. 2
The correct answer is c

412. An area border router can be connected to _______.
a. Only another router
b. Only another network
c. Only another area border router
d. Another router or another network
The correct answer is d

413. Which of the following usually has the least number of connections to other areas?
a. A transient link
b. A stub link
c. An area
d. An autonomous system
The correct answer is b

414. _______ is used in a dense multicast environment while _______ is used in a sparse multicast environment.
a. PIM-SM; PIM-DM
b. PIM; PIM-DM
c. PIM; PIM-SM
d. PIM-DM; PIM-SM
The correct answer is d

415. When a multicast router is not directly connected to another multicast router, a _______ can be formed to connect the two.
a. Logical core
b. Spanning tree
c. Physical tunnel
d. Logical tunnel
The correct answer is d

416. Which type of network using the OSPF protocol can have five routers attached to it?
a. Transient
b. Stub
c. Point-to-point
d. All the above
The correct answer is a

417. A WAN using the OSPF protocol that connects two routers is an example of a _______ type of OSPF network.
a. Stub
b. Point-to-point
c. Transient
d. Virtual
The correct answer is b

418. If four hosts on a network belong to the same group, a total of _______ sent in
a. One membership report is
b. Two membership reports are
c. Three membership reports are
d. Four membership reports are
The correct answer is b

419. A one-to-all communication between a source and all hosts on a network is classified as a _______ communication.
a. Unicast
b. Multicast
c. Broadcast
d. (a) and (b)
The correct answer is c

420. Which type of BGP message announces a route to a new destination?
a. Update
b. Open
c. Keep-alive
d. Notification
The correct answer is a

421. Which layer produces the OSPF message?
a. Data link
b. Transport
c. Application
d. Network
The correct answer is d

422. Which of the following is an exterior routing protocol?
a. RIP
b. OSPF
c. BGP
d. (a) and (b)
The correct answer is c

423. An area is _______.
a. Composed of at least two ASs
b. Another term for an internet
c. Part of an AS
d. A collection of stub areas
The correct answer is c

424. In an autonomous system with n areas, how many areas are connected to the backbone?
a. 1
b. n
c. n 1
d. n + 1
The correct answer is c

425. Which of the following is an interior routing protocol?
a. RIP
b. OSPF
c. BGP
d. (a) and (b)
The correct answer is d

426. OSPF is based on _______.
a. Distance vector routing
b. Path vector routing
c. Link state routing
d. (a) and (b)
The correct answer is c

427. BGP is based on _______.
a. Distance vector routing
b. Link state routing
c. Path vector routing
d. (a) and (b)
The correct answer is c

428. Which type of BGP message creates a relationship between two routers?
a. Keep-alive
b. Open
c. Update
d. Notification
The correct answer is b

429. Which type of network using the OSPF protocol always consists of just two connected routers?
a. Transient
b. Stub
c. Point-to-point
d. Virtual
The correct answer is c

430. Which type of network using the OSPF protocol is the result of a break in a link between two routers?
a. Virtual
b. Point-to-point
c. Transient
d. Stub
The correct answer is a

431. Which type of BGP message is sent by a router to close a connection?
a. Open
b. Update
c. Notification
d. Keep-alive
The correct answer is c

432. An IGMP query is sent from a _______ to a _______.
a. Router; host or router
b. Host; host
c. Host; router
d. Router; router
The correct answer is a

433. Which type of BGP message is sent by a system to notify another router of the sender's existence?
a. Keep-alive
b. Notification
c. Open
d. Update
The correct answer is a

434. An Ethernet LAN using the OSPF protocol with five attached routers can be called a _______ network.
a. Point-to-point
b. Stub
c. Transient
d. Virtual
The correct answer is c

435. In distance vector routing each router receives information directly from _______.
a. Its neighbors only
b. Every router on the network
c. Every router less than two units away
d. A table stored by the network hosts
The correct answer is a

436. A system uses group-shared trees for multicasting. If there are 100 sources and 5 groups, there is a maximum of _______ different trees.
a. 20
b. 100
c. 5
d. 500
The correct answer is c

437. _______ is a multicast routing protocol using source-based trees.
a. DVRMP
b. MOSPF
c. CBT
d. (a) and (b)
The correct answer is d

438. Pruning and grafting are strategies used in _______.
a. RPM
b. RPF
c. RPB
d. All the above
The correct answer is a

439. In distance vector routing a router sends out information _______.
a. Only when there is a change in its table
b. Only when a new host is added
c. At regularly scheduled intervals
d. Only when a new network is added
The correct answer is c

440. The _______ field of the IGMP message is all zeros in a query message.
a. Version
b. Type
c. Group address
d. Checksum
The correct answer is c

441. The _______ field of the IGMP message is 0x11 for a query message.
a. Version
b. Type
c. Checksum
d. d. (a) and (b)
The correct answer is d

442. A one-to-many communication between a source and a specific group of hosts is classified as a _______ communication.
a. Multicast
b. Unicast
c. Broadcast
d. (a) and (b)
The correct answer is a

443. A one-to-one communication between a source and one destination is classified as a _______ communication.
a. Unicast
b. Multicast
c. Broadcast
d. d. (a) and (b)
The correct answer is a

444. ________ is a multicasting application.
a. Teleconferencing
b. Distance learning
c. Information dissemination
d. All the above
The correct answer is d

445. A _______ is a data structure with nodes and edges and a hierarchical structure.
a. Graph
b. Leaf
c. Tree
d. Root
The correct answer is c

446. A system uses source-based trees for multicasting. If there are 100 sources and 5 groups, there is a maximum of _______ different trees.
a. 5
b. 20
c. 100
d. 500
The correct answer is d

447. In a _______ tree approach to multicasting, the combination of source and group determines the tree.
a. Shortest-group
b. Source-based
c. Spanning-source
d. Group-shared
The correct answer is b

448. In a _______ tree approach to multicasting, the group determines the tree.
a. Group-shared
b. Spanning-source
c. Shortest-group
d. Source-based
The correct answer is a

449. _______ is a multicast routing protocol using group-shared trees.
a. DVRMP
b. MOSPF
c. CBT
d. (a) and (b)
The correct answer is c

450. In _______ a network can receive a multicast packet from a particular source only through a designated parent router.
a. RPF
b. RPM
c. RPB
d. All the above
The correct answer is c

451. Dijkstra's algorithm is used to _______.
a. Create LSAs
b. Flood an internet with information
c. Create a link state database
d. Calculate the routing tables
The correct answer is d

452. A _______ message tells an upstream router to stop sending multicast messages for a specific group through a specific router.
a. Graft
b. Prune
c. Weed
d. Plum
The correct answer is b

453. The _______ is used by a router in response to a received-leave report.
a. Special query message
b. General query message
c. Membership report
d. Leave report
The correct answer is a

454. RIP is based on _______.
a. Link state routing
b. Dijkstra's algorithm
c. Path vector routing
d. Distance vector routing
The correct answer is d

455. A _______ message tells an upstream router to start sending multicast messages for a specific group through a specific router.
a. Weed
b. Prune
c. Plum
d. Graft
The correct answer is d

456. _______ uses multicast link state routing concepts to create source-based trees.
a. DVMRP
b. CBT
c. BVD
d. MOSPF
The correct answer is d

457. In the _______ protocol, a multicast packet is encapsulated inside a unicast packet with the core router as the destination.
a. DVMRP
b. CBT
c. MOSPF
d. BVD
The correct answer is b

458. The _______ is an IGMP message.
a. Query message
b. Membership report
c. Leave report
d. All the above
The correct answer is d

459. The _______ defines the client program.
a. Well-known port number
b. Ephemeral port number
c. IP address
d. Physical address
The correct answer is b

460. The _______ timer is used in the termination phase.
a. Retransmission
b. Time-waited
c. Persistence
d. Keep-alive
The correct answer is b

461. Which is a legal port address?
a. 0
b. 513
c. 65,535
d. All the above
The correct answer is d

462. The definition of reliable delivery includes _______.
a. Error-free delivery
b. Receipt of the complete message
c. In-order delivery
d. All the above
The correct answer is d

463. Which of the following does UDP guarantee?
a. Acknowledgments to the sender
b. Flow control
c. Sequence numbers on each user datagram
d. None of the above
The correct answer is d

464. The source port address on the UDP user datagram header defines _______.
a. The sending computer
b. The receiving computer
c. The application program on the receiving computer
d. The application program on the sending computer
The correct answer is d

465. A host can be identified by _______ while a program running on the host can be identified by _______.
a. A port number; an IP address
b. An IP address; a port number
c. An IP address; a host address
d. An IP address; a well-known port
The correct answer is b

466. Which of the following is not part of the UDP user datagram header?
a. Source port address
b. Checksum
c. Length of header
d. Destination port address
The correct answer is c

467. The _______ defines the server program.
a. IP address
b. Well-known port number
c. Ephemeral port number
d. Physical address
The correct answer is b

468. IP is responsible for _______ communication while TCP is responsible for _______ communication.
a. Process-to-process; node-to-node
b. Host-to-host; process-to-process
c. Process-to-process; host-to-host
d. Node-to-node; process-to-process
The correct answer is b

469. The _______ timer is needed to handle the zero window-size advertisement.
a. Persistence
b. Keep-alive
c. Retransmission
d. Time-waited
The correct answer is a

470. Connection establishment involves a _______ handshake.
a. Three-way
b. One-way
c. Two-way
d. None of the above
The correct answer is a

471. A special segment called a probe is sent by a sending TCP when the _______ timer goes off.
a. Persistence
b. Transmission
c. Keep-alive
d. Time-waited
The correct answer is a

472. The _______ address uniquely identifies a running application program.
a. IP address
b. NIC
c. Socket
d. Host
The correct answer is c

473. The _______ field is used to order packets of a message.
a. Sequence number
b. Acknowledgment number
c. Urgent pointer
d. Checksum
The correct answer is a

474. The _______ field is used for error detection.
a. Sequence number
b. Acknowledgment number
c. Urgent pointer
d. Checksum
The correct answer is d

475. Multiply the header length field by _______ to find the total number of bytes in the TCP header.
a. 4
b. 6
c. 8
d. 2
The correct answer is a

476. Urgent data require the urgent pointer field as well as the URG bit in the ______ field.
a. Sequence number
b. Control
c. Offset
d. Reserved
The correct answer is b

477. In ______, data are sent or processed at a very inefficient rate, such as 1 byte at a time.
a. Silly window syndrome
b. Sliding window syndrome
c. Nagle's syndrome
d. Delayed acknowledgment
The correct answer is a

478. The _______ timer keeps track of the time between the sending of a segment and the receipt of an acknowledgment.
a. Time-waited
b. Retransmission
c. Persistence
d. Keep-alive
The correct answer is b

479. To prevent silly window syndrome created by a receiver that processes data at a very slow rate, _______ can be used.
a. Clark's solution
b. Nagle's algorithm
c. Delayed acknowledgment
d. (a) or (c)
The correct answer is d

480. To prevent silly window syndrome created by a sender that sends data at a very slow rate, _______ can be used.
a. Nagle's algorithm
b. Clark's solution
c. Delayed acknowledgment
d. (a) or (c)
The correct answer is a

481. An ACK number of 1000 always means that _______.
a. 999 bytes has been successfully received
b. 1000 bytes has been successfully received
c. 1001 bytes has been successfully received
d. None of the above
The correct answer is d

482. The _______ timer prevents a long idle connection between two TCPs.
a. Keep-alive
b. Time-waited
c. Retransmission
d. Persistence
The correct answer is a

483. UDP and TCP are both _______ layer protocols.
a. Physical
b. Data link
c. Network
d. Transport
The correct answer is d

484. Which of the following functions does UDP perform?
a. End-to-end reliable data delivery
b. Process-to-process communication
c. Host-to-host communication
d. All the above
The correct answer is b

485. UDP needs the _______ address to deliver the user datagram to the correct application program.
a. Application
b. Internet
c. Physical
d. Port
The correct answer is d


486. Karn's algorithm is used in calculations by the _______ timer.
a. a. Time-waited
b. Retransmission
c. Persistence
d. Keep-alive
The correct answer is b

487. Slow start is used in conjunction with _______ as a TCP congestion control strategy.
a. Multiplicative increase
b. Multiplicative decrease
c. Additive increase
d. Additive decrease
The correct answer is c

488. The maximum length of time that traffic is generated at the peak rate is called the _______.
a. Effective bandwidth
b. Average data rate
c. Maximum burst size
d. Constant bit rate
The correct answer is c

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489. For a system using TCP, the sender window size is determined by the _______ window size.
a. Receiver
b. Sender
c. Congestion
d. (a) and (c)
The correct answer is d

490. _______ traffic features sudden data rate changes in very short periods of time.
a. Constant-bit-rate
b. Bursty
c. Variable-bit-rate
d. Peak-bit-rate
The correct answer is b

491. When the load is greater than the capacity, the delay _______.
a. Decreases
b. Goes to infinity
c. Increases linearly
d. Goes to zero
The correct answer is b

492. _______ is a closed-loop mechanism to alleviate congestion.
a. A choke point
b. Implicit signaling
c. Explicit signaling
d. All the above
The correct answer is d

493. The FECN informs the _________ of congestion while the BECN informs the _______ of congestion.
a. Sender; destination
b. Interface; sender
c. Destination; interface
d. Destination; sender
The correct answer is d

494. The _______ is the maximum data rate of the traffic.
a. Average data rate
b. Maximum burst size
c. Effective bandwidth
d. Peak data rate
The correct answer is d

495. _______ is a flow characteristic in which the delay varies for packets belonging to the same flow.
a. Choke point
b. Additive increase
c. Jitter
d. Throughput
The correct answer is b

496. In _______ queuing the first packet into the queue is the first packet out of the queue.
a. Priority
b. Weighted fair
c. FIFO
d. LIFO
The correct answer is c

497. In Frame Relay the transmission rate can never exceed _______.
a. Bc
b. The access rate
c. Be
d. CIR
The correct answer is b

498. _______ measures the variation in cell transmission time.
a. SCR
b. CVDT
c. PCR
d. MCR
The correct answer is b

499. If the SCR is 60,000, the PCR is 70,000, and the MCR is 55,000, what is the minimum number of cells that can be sent per second?
a. 60,000
b. 70,000
c. 55,000
d. 5000
The correct answer is c

500. The _______ traffic shaping method gives a host credit for its idle time.
a. Leaky bucket
b. Traffic bucket
c. Token bucket
d. Bursty bucket
The correct answer is c

501. A flow-based QoS model designed for IP is called _______.
a. RSVP
b. Integrated Services
c. Differentiated Services
d. Multicast trees
The correct answer is b

502. A signaling protocol that helps IP create a flow is called _______.
a. RSVP
b. Integrated Services
c. Differentiated Services
d. Multicast trees
The correct answer is a

503. RSVP uses _______ messages.
a. Path
b. Resv
c. Resource
d. (a) and (b)
The correct answer is d

504. In an RSVP reservation style called _______ filter, the router creates a single reservation that can be shared by a set of flows.
a. Fixed
b. Shared explicit
c. Wild card
d. All the above
The correct answer is b

505. Differentiated Services was designed to handle the _______ problem associated with Integrated Services.
a. Stability
b. Reservation
c. Scalability
d. All the above
The correct answer is c

506. A _______ is a Differentiated Services traffic conditioner.
a. Meter
b. Marker
c. Shaper
The correct answer is c

507. What is the relationship between the access rate and the CIR?
a. CIR plus Be is equal to the access rate.
b. CIR is always equal to the access rate.
c. CIR is greater than the access rate.
d. CIR is less than the access rate.
The correct answer is d

508. If the maximum CTD is 10 s and the minimum CTD is 1 s, the _______ is 9 s.
a. CDV
b. CLR
c. CTD
d. CER
The correct answer is a

509. A Frame Relay network is committed to transfer _______ bps without discarding any frames.
a. Be
b. Bc
c. CIR
d. (a) and (b)
The correct answer is b

510. The effective bandwidth is based on _______.
a. Average data rate
b. Peak data rate
c. Maximum burst size
d. All the above
The correct answer is d

511. The cell _______ is the difference between the CTD maximum and minimum.
a. Delay variation
b. Error ratio
c. Loss ratio
d. Transfer delay
The correct answer is a

512. The cell _______ is the ratio of lost cells to cells sent.
a. Delay variation
b. Error ratio
c. Loss ratio
d. Transfer delay
The correct answer is c

513. The _______ service class is particularly suitable for applications with bursty data.
a. CBR
b. ABR
c. VBR
d. UBR
The correct answer is b

514. The _________ service class is suitable for customers who need real-time video transmission without compression.
a. ABR
b. CBR
c. VBR
d. UBR
The correct answer is b

515. The _______ is greater than the SCR.
a. MCR
b. CVDT
c. PCR
d. All the above
The correct answer is c

516. The _______ is the fraction of the cells delivered in error.
a. CLR
b. CER
c. CTD
d. CDV
The correct answer is b

517. When added to Be, Bc should be less than the _______.
a. CIR
b. Committed burst size
c. Access rate
d. (a) and (b)
The correct answer is c

518. A connectionless iterative server uses _______ ports.
a. Well-known
b. Ephemeral
c. Active
d. (a) and (b)
The correct answer is a

519. The _______ socket is used with a protocol that directly uses the services of IP.
a. Raw
b. Stream
c. Datagram
d. Remote
The correct answer is a

520. A _______ server serves multiple clients, handling one request at a time.
a. Connectionless iterative
b. Connectionless concurrent
c. Connection-oriented iterative
d. Connection-oriented concurrent
The correct answer is a

521. A client issues _______ when it needs service from a server.
a. An active request
b. A finite open
c. An active open
d. A passive open
The correct answer is c

522. A _______ server serves multiple clients simultaneously.
a. Connectionless iterative
b. Connectionless concurrent
c. Connection-oriented iterative
d. Connection-oriented concurrent
The correct answer is d

523. The server program is _______ because it is always available, waiting for a client request.
a. Finite
b. Infinite
c. Active
d. Passive
The correct answer is b

524. A connection-oriented concurrent server uses _______ ports.
a. Well-known
b. Ephemeral
c. Active
d. (a) and (b)
The correct answer is d

525. Machine A requests service X from machine B. Machine B requests service Y from machine A. What is the total number of application programs required?
a. One
b. Two
c. Three
d. Four
The correct answer is d

526. A server program, once it issues _______, waits for clients to request its service.
a. An active request
b. A finite open
c. An active open
d. A passive open
The correct answer is d

527. _______ can request a service.
a. A socket interface
b. A client
c. A port
d. A server
The correct answer is b

528. _______ can provide a service.
a. An iterative server
b. A concurrent server
c. A client
d. (a) and (b)
The correct answer is d

529. The client program is _______ because it terminates after it has been served.
a. Finite
b. Infinite
c. Active
d. Passive
The correct answer is a

530. _______ processes requests one at a time.
a. An iterative server
b. A concurrent client
c. An iterative client
d. A concurrent server
The correct answer is a

531. The _______ socket is used with a connectionless protocol.
a. Raw
b. Stream
c. Datagram
d. Remote
The correct answer is c

532. _______ processes many requests simultaneously.
a. An iterative server
b. A concurrent client
c. An iterative client
d. A concurrent server
The correct answer is d

533. In a connection-oriented concurrent server, the _______ is used for connection only.
a. Well-known port
b. Infinite port
c. Ephemeral port
d. (b) and (c)
The correct answer is a

534. A _______ is an instance of a _______.
a. Program; process
b. Process; program
c. Process; service
d. Structure; process
The correct answer is b

535. The _______ socket is used with a connection-oriented protocol.
a. Raw
b. Stream
c. Datagram
d. Remote
The correct answer is b

536. In the string 219.46.123.107.in-addr.arpa, what is the network address of the host we are looking for?
a. 107.123.46.0
b. 107.0.0.0
c. 219.46.123.0
d. 107.123.0.0
The correct answer is b

537. In _______ resolution the client is in direct contact with at most one server.
a. A cache
b. A recursive
c. An iterative
d. All the above
The correct answer is b

538. In address-to-name resolution the _______ domain is used.
a. Reverse
b. Generic
c. Country
d. Inverse
The correct answer is d

539. How is the lifetime of a name-to-address resolution in cache memory controlled?
a. By the time-to-live field set by the server
b. By the time-to-live counter set by the server
c. By the time-to-live field set by the authoritative server
d. (b) and (c)
The correct answer is d

540. A DNS response is classified as ______ if the information comes from a cache memory.
a. Authoritative
b. Recursive
c. Unauthoritative
d. Iterative
The correct answer is c

541. A host with the domain name pit.arc.nasa.gov. is on the _______ level of the DNS hierarchical tree. (The root is level 1.)
a. Fourth
b. Fifth
c. Third
d. Not enough information given
The correct answer is b

542. A DNS _______ server's zone is the entire DNS tree.
a. Secondary
b. Root
c. Primary
d. All the above
The correct answer is b

543. To find the IP address of a host when the domain name is known, the _______ can be used.
a. Inverse domain
b. Generic domains
c. Country domains
d. (b) or (c)
The correct answer is a

544. A DNS _______ server gets its data from another DNS server.
a. Root
b. Primary
c. Secondary
d. All the above
The correct answer is c

545. A DNS _______ server creates, maintains, and updates the zone file.
a. Root
b. Primary
c. Secondary
d. All the above
The correct answer is b

546. A host with the domain name trinity.blue.vers.inc is on the _______ level of the DNS hierarchical tree. (The root is level 1.)
a. Fourth
b. Fifth
c. Third
d. Not enough information given
The correct answer is d

547. In the domain name chal.atc.fhda.edu, _______ is the least specific label.
a. fhda
b. edu
c. chal
d. atc
The correct answer is b

548. In the domain name chal.atc.fhda.edu, _______ is the most specific label.
a. Fhda
b. chal
c. atc
d. edu
The correct answer is b

549. In _______ resolution the client could directly contact more than one server.
a. An iterative
b. A cache
c. A recursive
d. All the above
The correct answer is a

550. Which of the following domain names would most likely use a country domain to resolve its IP address?
a. chal.atac.fhda.edu
b. kenz.acct.sony.jp
c. gsfc.nasa.gov
d. mac.eng.sony.com
The correct answer is b

551. A resolver is the _______.
a. Host machine
b. DNS client
c. DNS server
d. Root server
The correct answer is b

552. Which of the following is true?
a. FTP allows systems with different directory structures to transfer files.
b. FTP allows a system using ASCII and a system using EBCDIC to transfer files.
c. FTP allows a PC and a SUN workstation to transfer files.
d. All the above are true.
The correct answer is d

553. An email contains a textual birthday greeting, a picture of a cake, and a song. The text must precede the image. What is the content-type?
a. Multipart/parallel
b. Multipart/digest
c. Multipart/alternative
d. Multipart/mixed
The correct answer is d

554. During an FTP session the control connection is opened _______.
a. As many times as necessary
b. Exactly once
c. Exactly twice
d. All the above
The correct answer is b
555. The purpose of the MTA is _______.
a. Transferral of messages across the Internet
b. Message preparation
c. Envelope creation
d. (a) and (b)
The correct answer is a

556. In anonymous FTP, the user can usually _______.
a. Store files
b. Retrieve files
c. Navigate through directories
d. Do all the above
The correct answer is b

557. Which part of the mail created by the UA contains the sender and receiver names?
a. Header
b. Body
c. Envelope
d. Address
The correct answer is a

558. In the email address mackenzie@pit.arc.nasa.gov, what is the domain name?
a. mackenzie
b. mackenzie@pit.arc.nasa.gov
c. pit.arc.nasa.gov
d. (a) and (b)
The correct answer is c

559. The _______ field in the MIME header uses text to describe the data in the body of the message.
a. Content-transfer-encoding
b. Content-Id
c. Content-type
d. Content-description
The correct answer is b

560. The _______ field in the MIME header describes the method used to encode the data.
a. Content-Id
b. Content-description
c. Content-type
d. Content-transfer-encoding
The correct answer is d

561. The _______ field in the MIME header has type and subtype subfields.
a. Content-transfer-encoding
b. Content-type
c. Content-Id
d. Content-description
The correct answer is b

562. A JPEG image is sent as email. What is the content-type?
a. Multipart/mixed
b. Multipart/image
c. Image/basic
d. Image/JPEG
The correct answer is d

563. The purpose of the UA is _______.
a. Message preparation
b. Envelope creation
c. Transferral of messages across the Internet
d. (a) and (b)
The correct answer is d

564. The _______ field in the MIME header is the type of data and the body of the message.
a. Content-Id
b. Content-description
c. Content-type
d. Content-transfer-encoding
The correct answer is c

565. A message is fragmented into three email messages. What is the content-type?
a. Message/partial
b. Multipart/partial
c. Multipart/mixed
d. Message/RFC822
The correct answer is a

566. A client machine usually needs _______ to send email.
a. Only POP
b. Both SMTP and POP
c. Only SMTP
d. None of the above
The correct answer is c

567. In FTP, what attributes must be defined by the client prior to transmission?
a. Data type
b. File structure
c. Transmission mode
d. All the above
The correct answer is d

568. In FTP, there are three types of _______: stream, block, and compressed.
a. Data structures
b. Transmission modes
c. Files
d. All the above
The correct answer is b

569. In FTP, ASCII, EBCDIC, and image define an attribute called _______.
a. Data structure
b. Transmission mode
c. File type
d. All the above
The correct answer is c

570. In FTP, when you _______, it is copied from the server to the client.
a. Retrieve a file
b. Store a file
c. Retrieve a list
d. (a) and (c)
The correct answer is d

571. In FTP, when you _______, it is copied from the client to the server.
a. Retrieve a file
b. Store a file
c. Retrieve a list
d. (a) and (c)
The correct answer is b

572. An email contains a textual birthday greeting, a picture of a cake, and a song. The order is not important. What is the content-type?
a. Multipart/digest
b. Multipart/alternative
c. Multipart/mixed
d. Multipart/parallel
The correct answer is d

573. During an FTP session the data connection is opened _______.
a. Exactly once
b. Exactly twice
c. As many times as necessary
d. All the above
The correct answer is c

574. Which of the following is a retrieval method?
a. HTTP
b. FTP
c. TELNET
d. All the above
The correct answer is d

575. A request message always contains _______.
a. A status line, a header, and a body
b. A status line and a header
c. A header and a body
d. A request line and a header
The correct answer is d

576. Which of the following is present in both a request line and a status line?
a. URL
b. Status code
c. HTTP version number
d. Status phrase
The correct answer is c

577. Which of the following is not a client program in WWW?
a. FTP
b. HTTP
c. HTML
d. TELNET
The correct answer is c

578. A user wants to replace a document with a newer version; the request line contains the _______ method.
a. PUT
b. GET
c. POST
d. COPY
The correct answer is a

579. The _______ header can specify the client configuration and the client's preferred document format.
a. Request
b. Response
c. General
d. Entity
The correct answer is a

580. The _______ tags enclose binary code or byte code.
a. Executable contents
b. Image
c. List
d. Hyperlink
The correct answer is a

581. Which type of Web document is run at the client site?
a. Dynamic
b. Active
c. Static
d. All the above
The correct answer is b

582. HTTP has similarities to both _______ and _______.
a. FTP; MTV
b. FTP; URL
c. FTP; SNMP
d. FTP; SMTP
The correct answer is d

583. A user needs to send the server some information. The request line method is ______.
a. OPTION
b. POST
c. PATCH
d. MOVE
The correct answer is b

584. A response message always contains _______.
a. A header and a body
b. A status line, a header, and a body
c. A request line and a header
d. A status line and a header
The correct answer is c

585. The _______ header supplies information about the body of a document.
a. General
b. Request
c. Entity
d. Response
The correct answer is c

586. The _______ header can specify the server configuration or provide information about a request.
a. General
b. Request
c. Response
d. Entity
The correct answer is c

587. Hypertext documents are linked through _______.
a. TELNET
b. Pointers
c. DNS
d. Homepages
The correct answer is b

588. Which of the following is an interpreter?
a. CGI
b. FTP
c. HTTP
d. HTML
The correct answer is d

589. What are the components of a browser?
a. Controller, client program, interpreter
b. Retrieval method, host computer, path name
c. Hypertext, hypermedia, HTML
d. All the above
The correct answer is a

590. A user needs to retrieve a document from the server; the request line contains the _______ method.
a. GET
b. HEAD
c. POST
d. PUT
The correct answer is a

591. Which type of Web document is fixed-content and is created and stored at the server site?
a. Dynamic
b. Active
c. Static
d. All the above
The correct answer is c

592. The _______ of a Web page contains the title and parameters used by the browser.
a. Attributes
b. Tags
c. Head
d. Body
The correct answer is c

593. Which type of Web document is created at the server site only when requested by a client?
a. Active
b. Static
c. Dynamic
d. All the above
The correct answer is c

594. In < IMG SRC="Pictures/book1.gif" ALIGN=middle> ALIGN is _______.
a. The head
b. The body
c. A tag
d. An attribute
The correct answer is d

595. A user wants to copy a file to another location; the request line contains the _______ method.
a. PUT
b. PATCH
c. COPY
d. POST
The correct answer is c

596. What does the URL need to access a document?
a. Path name
b. Host computer
c. Retrieval method
d. All the above
The correct answer is d

597. Which type of Web document is transported from the server to the client in binary form?
a. Active
b. Static
c. Dynamic
d. All the above
The correct answer is a

598. An ending tag is usually of the form _______
a. <tagname>
b. <tagname!>
c. </tagname>
The correct answer is c

599. An applet is a small application program written in _______
a. Shell script
b. Java
c. C
d. C++
The correct answer is b

600. Stock quotations are posted on the Web. This is probably a(n) _______ document.
a. Passive
b. Dynamic
c. Active
d. Static
The correct answer is b

601. Updates for a satellite's coordinates can be obtained on the WWW. This is probably a(n) _______ document.
a. Passive
b. Dynamic
c. Active
d. Static
The correct answer is b

602. A user needs to move a file to another location. The request line method is _______.
a. PATCH
b. MOVE
c. PUT
d. GET
The correct answer is b

603. Which category of HTML tags allows the listing of documents?
a. Image
b. Hyperlink
c. List
d. Executable contents
The correct answer is c

604. A program can use _______ to write a CGI program.
a. Bourne shell script
b. Perl
c. C
d. Any of the above
The correct answer is d

605. An unemployed actor has posted his resume on the Web. This is probably a(n) _______ document.
a. Passive
b. Dynamic
c. Active
d. Static
The correct answer is d

606. The server receives input from a browser through _______.
a. An attribute
b. A form
c. A tag
d. Any of the above
The correct answer is b

607. Output from a CGI program is _______.
a. Text
b. Graphics
c. Binary data
d. Any of the above
The correct answer is d

608. _______ is used to enable the use of active documents.
a. CGI
b. Java
c. HTML
d. All the above
The correct answer is c

609. Java is _______.
a. A programming language
b. A run-time environment
c. A class library
d. All the above
The correct answer is d

610. An applet is _______ document application program.
a. An active
b. A passive
c. A static
d. A dynamic
The correct answer is a

611. In a real-time video conference, data from the server are _______ to the client sites.
a. Unicast
b. Broadcast
c. Multicast
d. None of the above
The correct answer is c

612. A _______ adds signals from different sources to create a single signal.
a. Mixer
b. Translator
c. Timestamp
d. Sequence number
The correct answer is a

613. The RTCP _______ message shuts down a stream.
a. Application-specific
b. Source description
c. Bye
d. Farewell
The correct answer is c

614. A standard that allows a telephone (connected to a public telephone network) to talk to a computer connected to the Internet is _______.
a. SIP
b. H.323
c. IEEE 802.3
d. V.90bis
The correct answer is b

615. A _______ changes the format of a high-bandwidth video signal to a lower-quality narrow-bandwidth signal.
a. Timestamp
b. Sequence number
c. Mixer
d. Translator
The correct answer is d

616. An RTP packet is encapsulated in a(n) _______.
a. IP datagram
b. RTCP packet
c. UDP user datagram
d. TCP segment
The correct answer is c

617. The last step in JPEG, _______, removes redundancies.
a. Blocking
b. Compression
c. Quantization
d. Vectorization
The correct answer is b

618. A _______ shows when a packet was produced relative to the first or previous packet.
a. Sequence number
b. Threshold
c. Timestamp
d. Playback buffer
The correct answer is c

619. _______ is a protocol to set up and terminate a connection between a computer on the Internet and a telephone (connected to a public telephone network).
a. H.245
b. H.225
c. H.323
d. Q.931
The correct answer is d

620. TCP is not suitable for real-time traffic because _______.
a. There is no provision for timestamping
b. There is no support for multicasting
c. Missing packets are retransmitted
d. All the above
The correct answer is d

621. JPEG encoding involves _______, a process that reveals the redundancies in a block.
a. Quantization
b. Vectorization
c. Blocking
d. The DCT
The correct answer is d

622. The RTCP _______ report informs the sender and other receivers about the quality of service.
a. Sender
b. QoS
c. Receiver
d. Passive
The correct answer is c

623. _______ is an application layer protocol that establishes, maintains, and terminates a multimedia session.
a. DCT
b. SIP
c. RTCP
d. JPEG
The correct answer is b

624. For streaming stored audio/video, the _______ holds information about the audio video file.
a. Jitter
b. Alpha file
c. Beta file
d. Metafile
The correct answer is d

625. _______ is a control protocol that adds functionalities to the streaming process.
a. TCP/IP
b. RTSP
c. HTTP
d. SIP
The correct answer is b

626. The audio/video stream is sent by the media server to the _______.
a. Media player
b. Browser
c. Web server
d. None of the above
The correct answer is a

627. Voice over IP is a(n) ________ audio/video application.
a. Interactive
b. Streaming stored
c. Streaming live
d. None of the above
The correct answer is a

628. _______ is a SIP message type.
a. INVITE
b. CANCEL
c. OPTIONS
d. All the above
The correct answer is d

629. A _______ is involved in an SIP mechanism to find the IP address of a callee.
a. Proxy server
b. Registrar server
c. Media server
d. (a) and (b)
The correct answer is d

630. _______ are used to number the packets of a real-time transmission.
a. Translators
b. Timestamps
c. Playback buffers
d. Sequence numbers
The correct answer is d

631. In the _______ the encryption of each 8-byte block is independent of the others.
a. CVF
b. CSM
c. ECB mode
d. CBC mode
The correct answer is c

632. In the public-key method of cryptography, which key is publicly known?
a. Encryption key only
b. Decryption key only
c. Both
d. None of the above
The correct answer is a

633. A cipher is _______.
a. An encryption algorithm
b. A decryption algorithm
c. A private key
d. (a) or (b)
The correct answer is d

634. Before a message is encrypted, it is called _______.
a. Ciphertext
b. Cryptotext
c. Cryptonite
d. Plaintext
The correct answer is d

635. If 20 people need to communicate using symmetric-key cryptography, _______ symmetric keys are needed.
a. 190
b. 200
c. 19
d. 20
The correct answer is a

636. The _______ is an example of polyalphabetic substitution.
a. P-box
b. Vigenere cipher
c. S-box
d. Product block
The correct answer is b

637. In the symmetric-key method of cryptography, which key is publicly known?
a. Encryption key only
b. Decryption key only
c. Both
d. None of the above
The correct answer is d

638. The RSA algorithm uses a _______ cryptography method.
a. Private-key
b. Symmetric-key
c. Denominational
d. Public-key
The correct answer is d

639. The _______ is a block cipher.
a. P-box
b. S-box
c. Product block
d. All the above
The correct answer is d

640. We use an cryptography method in which the plaintext AAAAAA becomes the ciphertext BCDEFG. This is probably _______.
a. Monoalphabetic substitution
b. Transposition
c. Polyalphabetic substitution
d. None of the above
The correct answer is c

641. One way to encrypt and decrypt long messages is through the use of the _______.
a. ECB mode
b. CBC mode
c. CFM
d. All the above
The correct answer is d

642. An initialization vector is needed in the _______.
a. CSM
b. CBC mode
c. CVF
d. (a) and (b)
The correct answer is d

643. In the public-key method of cryptography, only the receiver has possession of the _______.
a. Public key
b. Both keys
c. Private key
d. None of the above
The correct answer is c

644. After a message is decrypted, it is called _______.
a. Ciphertext
b. Cryptotext
c. Cryptonite
d. Plaintext
The correct answer is d

645. We use a cryptography method in which the character Z always substitutes for the character G. This is probably _______.
a. Polyalphabetic substitution
b. Transpositional
c. Monoalphabetic substitution
d. None of the above
The correct answer is c

646. A protocol called _______ describes the certificate issued by a CA in a structural way.
a. KDC
b. X.509
c. CA level 1
d. Kerberos
The correct answer is b

647. Windows 2000 uses an authentication protocol called _______.
a. Otway-Rees
b. Kerberos
c. Diffie-Hellman
d. Needham-Schroeder
The correct answer is b

648. In the digital signature technique, the sender of the message uses _______ to create ciphertext.
a. His or her own public key
b. His or her own private key
c. His or her own symmetric key
d. The receiver's private key
The correct answer is b

649. A _______ is a trusted third party that solves the problem of symmetric-key distribution.
a. TLS
b. Firewall
c. CA
d. KDC
The correct answer is d

650. In a _______ attack, a message captured by an intruder is illegally sent a second time.
a. Return
b. Replay
c. Man-in-the-middle
d. Bucket brigade
The correct answer is b

651. In the _______ protocol, a nonce is decremented by 1 so that an intruder cannot send the exact same message a second time.
a. Needham-Schroeder
b. Diffie-Hellman
c. Otway-Rees
d. Kerberos
The correct answer is a

652. If user A wants to send an encrypted message to user B, the plaintext is encrypted with the public key of _______.
a. The network
b. User A
c. User B
d. (a) or (b)
The correct answer is c

653. When symmetric-key encryption is combined with private-key encryption, the _______ key is encrypted with the public key.
a. Skeleton
b. Private
c. Public
d. Symmetric
The correct answer is d

654. The _______ issues tickets for the real server.
a. Real server
b. Data server
c. AS
d. TGS
The correct answer is c

655. In _______-key cryptography, everyone has access to all the public keys.
a. Private
b. Certified
c. Symmetric
d. Public
The correct answer is c

656. In the digital signature technique, the receiver of the message uses _______ to create plaintext.
a. The sender's public key
b. Her or his own symmetric key
c. Her or his own private key
d. Her or his own public key
The correct answer is a

657. A _______ is a large number used only once that helps distinguish a fresh authentication request from a repeated one.
a. Ticket
b. Realm
c. Nonce
d. Public key
The correct answer is c

658. A _______ certifies the binding between a public key and its owner.
a. KDC
b. TLS
c. CA
d. Firewall
The correct answer is c

659. In an authentication using symmetric keys, if 10 people need to communicate, we need _______ keys.

a. 90
b. 10
c. 20
d. 45
The correct answer is d

660. In the _______ protocol, the symmetric key is K = G<sup>xy</sup> mod N, where G and N are public numbers.
a. Needham-Schroeder
b. Otway-Rees
c. Diffie-Hellman
d. Kerberos
The correct answer is c

661. In a _______ attack, an intruder comes between two communicating parties intercepting and replying to their messages.
a. Bucket-in-the-middle
b. Replay
c. Return
d. Man-in-the-middle
The correct answer is d

662. A _______ is a trusted third party that establishes a symmetric key between two parties who wish to communicate.
a. PKI
b. TGS
c. KDC
d. CA
The correct answer is c

663. _______ is an authentication protocol that needs an authentication server and a ticket-granting server.
a. Needham-Schroeder
b. Diffie-Hellman
c. Otway-Rees
d. Kerberos
The correct answer is d

664. The _______ is the KDC in the Kerberos protocol.
a. Real server
b. Data server
c. AS
d. TGS
The correct answer is c

665. The _______ field in the authentication header and the ESP header define the security method used in creating the authentication data.
a. Authentication data
b. SPI
c. Padding
d. Sequence number
The correct answer is b

666. Tunneling is a technique in which the IP datagram is first _______ and then _______.
a. Encapsulated in another datagram; encrypted
b. Encrypted; encapsulated in another datagram
c. Authenticated; encrypted
d. Encrypted; authenticated
The correct answer is b

667. _______ is an IP layer security protocol that only provides integrity and authentication.
a. PGP
b. ESP
c. IPSec
d. AH
The correct answer is d

668. An _______ is a private network with no external access that uses the TCP/IP suite.
a. Internet
b. Intranet
c. internet
d. Extranet
The correct answer is b

669. IPSec requires a logical connection between two hosts using a signaling protocol called _______.
a. PGP
b. TLS
c. AH
d. SA
The correct answer is d

670. An _______ is a private network with limited external access that uses the TCP/IP suite.
a. Intranet
b. Extranet
c. Internet
d. internet
The correct answer is b

671. The handshake protocol and data exchange protocol are part of _______.
a. TLS
b. CA
c. KDC
d. SSH
The correct answer is a

672. _______ is a collection of protocols that provide security at the IP layer level.
a. TLS
b. SSH
c. IPSec
d. PGP
The correct answer is c

673. A method to provide for the secure transport of email is called _______.
a. TLS
b. PGP
c. SA
d. IPSec
The correct answer is b

674. A VPN uses _______ to guarantee privacy.
a. IPSec
b. Tunneling
c. Both (a) and (b)
d. None of the above
The correct answer is c

675. A _______ can forward or block messages based on the information in the message itself.
a. Message digest
b. Proxy firewall
c. Packet-filter firewall
d. Private key
The correct answer is b

676. _______ is an IP layer security protocol that provides privacy as well as integrity and authentication.
a. AH
b. PGP
c. IPSec
d. ESP
The correct answer is d

677. _______ is a transport layer security protocol.
a. PGP
b. IPSec
c. TLS
d. AH
The correct answer is c

678. An IP datagram carries an authentication header if the _______ field of the IP header has a value of 51.
a. Protocol
b. Security parameter index
c. Sequence number
d. Next-header
The correct answer is a

679. A _______ network is totally isolated from the global Internet.
a. Private
b. Hybrid
c. Virtual private
d. Any of the above
The correct answer is a

680. A _______ network can use a leased line for intraorganization communication and the Internet for interorganization communication.
a. Private
b. Hybrid
c. Virtual private
d. Any of the above
The correct answer is b

681. In a VPN, _______ encrypted.
a. The inner datagram is
b. Neither the inner nor the outer datagram is
c. The outer datagram is
d. Both inner and outer datagrams are
The correct answer is d

682. A _______ can forward or block packets based on the information in the network layer and transport layer headers.
a. Proxy firewall
b. Message digest
c. Packet-filter firewall
d. Private key
The correct answer is c