Forouzan QandA

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There are ______________ Internet service providers. A) regional B) local C) national and international D) all of the above  ______ refers to the physical or logical arrangement of a network. A) Topology B) Mode of operation C) Data flow D) None of the above A ______ is a data communication system spanning states, countries, or the whole world. A) MAN B) WAN C) LAN D) none of the above A _______ connection provides a dedicated link between two devices. A) primary B) multipoint C) point-to-point D) secondary Which topology requires a multipoint connection? A) Bus B) Star C) Mesh D) Ring A ________ is a set of rules tha t governs data communication. A) protocol B) forum C) standard D) none of the above In a ______ connection, two and only two devices are connected by a dedicated link. A) multipoint B) point-to-point C) (a) and (b) D) none of the above The information to be communicated in a data communications system is the _______. A) Medium B) Protocol C) Message D) Transmission  ________ defines how a particular pattern to be interpreted, and what action is to be taken based on that interpretation. A) Syntax B) Semantics C) Timing D) None of the above 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 A television broadcast is an example of _______ transmission. A) half-duplex

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B) simplex C) full-duplex D) automatic Data flow between two devices can occur in a _______ way. A) simplex B) half-duplex C) full-duplex D) all of the above  _______ are special-interest special-interest groups that quickly test, evaluate, evaluate, and standardize new technologies. A) Standards organizations B) Regulatory agencies C) Forums D) All of the above Which agency developed standards for physical connection interfaces and electronic signaling specifications? A) ISO B) ITU-T C) ANSI D) EIA A _______ is a data communication system within a building, plant, o r campus, or between nearby buildings. A) LAN B) MAN C) WAN D) none of the above  _______ refers to two characteristics: when data should be sent and how fast it can be sent. A) Semantics B) Timing C) Syntax D) none of the above This was the first network. A) CSNET B) NSFNET C) ARPANET D) ANSNET Devices may be arranged in a _____ topology. A) mesh B) ring C) bus D) all of the above  _______ is the protocol suite for the current Internet. A) UNIX B) NCP C) TCP/IP D) ACM  ________ is a collection collection of many separate networks. A) A WAN B) An internet C) A LAN D) None of the above In a ________ connection, three or more devices share a link. A) point-to-point B) multipoint

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C) (a) and (b) D) none of the above Which organization has authority over interstate and international commerce in the communications field? A) FCC B) IEEE C) ITU-T D) ISOC In the original ARPANET, _______ were directly connected together. A) routers B) host computers C) networks D) IMPs Communication between a computer and a keyboard involves ______________ transmission. A) simplex B) half-duplex C) full-duplex D) ; automatic Which topology requires a central controller or hub? A) Mesh B) Bus C) Star D) Ring The _______ is the physical path over which a message travels. A) Protocol B) Signal C) Medium D) All the above In a _______ connection, more than two devices can share a single link. A) multipoint B) point-to-point C) primary D) secondary  _______ refers to the structure or format format of the data, meaning the order order in which they are presented. A) Semantics B) Syntax C) Timing D) All of the above An unauthorized user is a network _______ issue. A) Security B) Reliability C) Performance D) All the above  ________ is an idea or concept that is a precursor precursor to an Internet standard. A) RCF B) ID C) RFC D) none of the above In _______ transmission, the channel capacity is shared by both communicating devices at all times. A) simplex B) half-duplex C) full-duplex D) half-simplex

32. The ______ layer adds a header to the packet coming from the upper layer that includes the logical addresses of the sender and receiver. A) data link B) network C) physical D) none of the above 33. Which of the following is an application layer service? A) File transfer and access B) Mail service C) Remote log-in D) All the above 34. When data are transmitted from device A to device B, the header from A's layer 4 is read by B's _______ layer. A) Transport B) Application C) Physical D) None of the above 35.  __________ provides provides full transport layer services to applications. A) UDP B) TCP C) ARP D) none of the above 36. The process-to-process delivery of the entire message is the responsibility of the _______ layer. A) Transport B) Application C) Physical D) Network 37. The ______ layer is responsible for moving frames from one hop (node) to the next. A) transport B) data link C) physical D) none of the above 38. The _______ layer is responsible for delivering data units from one station to the next without errors. A) physical B) data link C) transport D) network 39. The session, presentation, and application layers are the ____ support layers . A) user B) network C) both (a) and (b) D) neither (a) nor (b) 40. The physical, data link, and network layers are the ______ support layers. A) network B) user C) both (a) and (b) D) neither (a) nor (b) 41. The ________ layer is responsible for the process-to-process delivery of the entire message. A) transport B) physical C) network

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D) data link The _______ layer lies between the network layer and the a pplication layer. A) Data link B) Transport C) Physical D) None of the above The Internetworking Protocol (IP) is a _ _______ protocol. A) connection-oriented B) reliable C) both a and b D) none of the above The _______ layer links the network support layers and the user support layers. A) session B) transport C) data link D) network ICMPv6 includes _______. A) IGMP B) ARP C) RARP D) a and b The ____ address uniquely defines a host on the Internet. A) IP B) port C) specific D) physical The _______ layer coordinates the functions required to transmit a bit stream over a physical medium. A) data link B) transport C) network D) physical The ______ layer is responsible for the source-to-destination delivery of a packet across multiple network links. A) network B) physical C) data link D) transport Mail services are available to network users through the _______ layer. A) Transport B) Physical C) Data link D) Application The ____ created a model called the Open Sy stems Interconnection, which allows diverse systems to communicate. A) IEEE B) ISO C) OSI D) none of the above The _______ layer changes bits into electromagnetic signals. A) Physical B) Transport C) Data link D) None of the above

52. IPv6 has _______ -bit addresses. A) 128 B) 32 C) 64 D) variable 53. The_____ address identifies a process on a host. A) specific B) port C) IP D) physical 54. The_________ layer is responsible for the delivery of a message f rom one process to another. A) transport B) network C) physical D) none of the above 55. The _________ layer enables the users to access the network. A) application B) physical C) data link D) transport 56. The TCP/IP _______ layer is equivalent to the combined session, presentation, and application layers of the OSI model. A) data link B) network C) physical D) application 57. When a host on network A sends a message to a host on network B, which address does the router look at? A) logical B) physical C) port D) none of the above 58. As the data packet moves from the upper to the lower layers, headers are _______. A) Rearranged B) Removed C) Added D) Modified 59. The physical layer is concerned with the movement of _______ over the physical medium. A) dialogs B) protocols C) bits D) programs 60. To deliver a message to the correct application program running on a host, the _______ address must be consulted. A) physical B) port C) IP D) none of the above 61. Ethernet uses a ______ physical address that is imprinted on the network interface card (NIC). A) 32-bit B) 6-byte C) 64-bit D) none of the above

62. The _______ layer is the layer closest to the transmission medium. A) Network B) Transport C) Physical D) Data link 63. The OSI model consists of _______ layers. A) eight B) seven C) five D) three 64. The ________ address, also known as the link address, is the address of a node as defined by its LAN or WAN. A) IP B) port C) specific D) physical 65. Layer 2 lies between the physical layer and the _______ layer. A) Data link B) Transport C) Network D) None of the above 66. Why was the OSI model developed? A) The rate of data transfer was increasing exponentially B) Standards were needed to allow any two systems to communicate C) Manufacturers disliked the TCP/IP protocol suite. D) None of the above 67. In the OSI model, as a data packet moves from the lower to the upper layers, headers are _______. A) removed B) added C) rearranged D) modified 68. In the OSI model, when data is transmitted from device A to device B, the header from A's layer 5 is read by B's _______ layer. A) session B) physical C) transport D) presentation 69. The seven-layer _____ model provides guidelines for the development of universally compatible networking protocols. A)ISO B)OSI C)IEEE D) none of the above 70. The Internet model consists of _______ layers. A)Eight B)Seven C)Five D) Three 71. In the OSI model, what is the main function of the transport layer? A) process-to-process message delivery B)node-to-node delivery C)synchronization D) updating and maintenance of routing tables

72.  _______ is a process-to-process protocol that adds only port addresses, checksum error control, and length information to the data from the upper layer. A)IP B)TCP C)UDP D) none of the above 73. The ______ layer establishes, maintains, and synchronizes the interactions between communicating devices. A) session B) physical C) transport D) network 74. A port address in TCP/IP is ______ bits long. A) 16 B) 32 C) 48 D) none of the above 75. In the OSI model, encryption and decryption are functions of the ________ layer. A) application B) presentation C) session D) transport 76. TCP/IP is a ______ hierarchical protocol suite developed ____ the OSI model. A) five-layer; before B) six-layer; before C) seven-layer; before D) five-layer; after 77. The ________ address, also known as the link address, is the address of a node as defined by its LAN or WAN. A) logical B) port C) physical D) none of the above 78. The _______ model shows how the network functions of a computer ought to be organized. A) ANSI B) CCITT C) ISO D) OSI 79. The _______ layer ensures interoperability between communicating devices through transformation of data into a mutually agreed upon format. A) network B) presentation C) transport D) data link 80. 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 81.  _________ can impair a signal. A) Noise B) Attenuation C) Distortion

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D) All of the above  ________is the rate of change with respect to time. A) Time B) Frequency C) Amplitude D) Voltage 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 equals P1 B) P2 is zero C) P2 is much larger than P1 D) P2 is much smaller than P1 Baseband transmission of a digital signal is possible only if we have a ____ channel. A) bandpass B) low-pass C) high rate D) low rate  ________ is a type of transmission impairment in which the signal loses strength due to the resistance of the transmission medium. A) Distortion B) Attenuation C) Noise D) Decibel A sine wave in the ______ domain ca n be represented by one single spike in the _____ d omain. A) time; phase B) frequency; time C) time; frequency D) phase; time If the bandwidth of a signal is 5 KHz and the lowest frequency is 52 K Hz, what is the highest frequency? A) 5 KHz B) 47 KHz C) 57 KHz D) 10 KHz In a time-domain plot, the horizontal axis is a measure of ________. A) phase B) signal amplitude C) frequency D) time  _______ data are continuous and take continuous values. A) digital B) analog C) a or b D) none of the above Frequency and period are ______. A) proportional to each other B) inverse of each other C) the same D) none of the above When propagation speed is multiplied by propagation time, we get the ________. A) wavelength of the signal B) throughput C) distance a signal or bit has traveled D) distortion factor

92. A _________ sine wave is not useful in data communications; we need to send a _______ signal. A) single-frequency; composite B) composite; single-frequency This is the correct answer. C) single-frequency; double-frequency D) none of the above 93. The _________ product defines the number of bits that can fill the link. A) delay-amplitude B) frequency-amplitude C) bandwidth-period D) bandwidth-delay 94.  _______ signals can have only a limited number of values. A) Digital B) Analog C) A or B D) None of the above 95. Before data can be transmitted, they must be transformed to ________. A) periodic signals B) electromagnetic signals C) aperiodic signals D) low-frequency sine waves 96. Data can be ________. A) digital B) analog C) A or B D) none of the above 97.  ________ 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) Noise B) Distortion C) Attenuation D) Decibel 98. Signals can be ________. A) digital B) analog C) either (a) or (b) D) neither (a) nor (b) 99. A sine wave is ________. A) periodic and discrete B) aperiodic and discrete C) periodic and continuous D) aperiodic and continuous 100. _______ data have discrete states and take discrete values. A) Analog B) Digital C) A or B D) None of the above 101. For a ______ channel, we need to use the Shannon capacity to find the maximum bit rate. A) noiseless B) noisy C) low-pass D) bandpass 102. What is the bandwidth of a signal that ranges from 1 MHz to 4 MHz? A) 1 KHz

B) 3 MHz C) 4 MHz D) none of the above 103. _____ signals can have an infinite number of values in a range. A) Analog B) Digital C) A or B D) None of the above 104. A(n)_________ signal is a composite analog signal with an infinite bandwidth. A) digital B) analog C) either (a) or (b) D) neither (a) nor (b) 105.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 106.The _____ of a composite signal is the difference between the highest and the lowest frequencies contained in that signal. A) period B) bandwidth C) frequency D) amplitude 107. ________ is a type of transmission impairment in which an outside source such as crosstalk corrupts a signal. A) Noise B) Distortion C) Attenuation D) Decibel 108. _______ describes the position of the waveform relative to time 0. A) Amplitude B) Phase C) Frequency D) Voltage 109.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 110.As frequency increases, the period ________. A) increases B) decreases C) doubles D) remains the same 111.If the available channel is a ____ channel, we cannot send a digital signal directly to the channel. A) low-pass B) low rate C) bandpass D) high rate 112.For a ______ channel, the Nyquist bit rate formula defines the theoretical maximum bit rate. A) low-pass

B) bandpass C) noisy D) noiseless 113. In a frequency-domain plot, the horizontal axis measures the ________. A) phase B) frequency C) slope D) peak amplitude 114.Which of the following encoding methods does not provide for synchronization? A) RZ B) NRZ-L C) NRZ-I D) Manchester 115.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) 200 samples/s B) 500 samples/s C) 1000 samples/s D) 1200 samples/s 116. In asynchronous transmission, the gap time between bytes is _ ______. A) variable B) fixed C) zero D) a function of the data rate 117.  ______ substitutes eight consecutive zeros with 000VB0VB. A) B4B8 B) B8ZS C) HDB3 D) none of the above 118.The most common technique to change an a nalog signal to digital data is called __________. A) sampling B) PAL C) PCM D) none of the above 119.The minimum bandwidth of Manchester and differential Manchester is ____ that of NRZ. A) the same as B) twice C) thrice D) none of the above 120. The signal rate is sometimes called the ____ rate. A) bit B) baud C) signal D) none of the above 121. Unipolar, bipolar, and polar encoding are types of _______ encoding. A) line B) block C) NRZ D) Manchester 122.  ________ is normally referred to as mB/nB coding; it replaces each m-bit group with an n-bit group. A) Line coding B) Block coding C) Scrambling

D) None of the above 123. In ______ schemes, the voltages are on the both sides of the time axis. For example, the voltage level for 0 can be positive and the voltage level for 1 can be negative. A) unipolar B) bipolar C) polar D) all of the above 124. The ________ rate defines the number of data elements sent in 1s; the ______ rate is the number of signal elements sent in 1s. A) signal; data B) data; signal C) baud; bit D) none of the above 125. The idea of RZ and the idea of NRZ-L are combined into the ________ scheme. A) Manchester B) differential Manchester C) both (a) and (b) D) neither (a) nor (b) 126. ________ provides synchronization without increasing the number of bits. A) Line coding B) Block coding C) Scrambling D) None of the above 127. The Nyquist theorem specifies the minimum sampling rate to be_______. A) equal to the lowest frequency of a signal B) equal to the highest frequency of a signal C) twice the bandwidth of a signal D) twice the highest frequency of a signal 128. PCM is an example of _______ conversion. A) analog-to-analog B) analog-to-digital C) digital-to-digital D) digital-to-analog 129. There are three sampling methods: __________. A) ideal, natural, and flat-top B) ideal, sampled, and flat-top C) quantized, sampled, and ideal D) none of the above 130. In _______encoding, we use three levels: positive, zero, and negative. A) unipolar B) polar C) bipolar D) none of the above 131. Block coding can help in _______ at the receiver. A) Synchronization B) Error detection C) Attenuation D) (a) and (b) 132. In Manchester and differential Manchester encoding, the transition at the middle of the bit is used for A) bit transfer B) synchronization C) baud transfer D) none of the above

133. _______ encoding has a transition at the beginning of each 0 bit. A) Differential Manchester B) Manchester C) RZ D) All the above 134. In ______, the change or lack of change in the level of the voltage determines the value of the bit. A) NRZ-L B) NRZ-I C) both (a) and (b) D) neither (a) nor (b) 135. In ___________ there is always a transition at the middle of the bit, but the bit values are determined at the beginning of the bit. If the next bit is 0, there is a transition; if the next bit is 1, there is none. A) Manchester B) differential Manchester C) both (a) and (b) D) neither (a) nor (b) 136. In _______ encoding, the duration of the bit is divided into two halves. The voltage remains at one level during the first half and moves to the other level in the second half. The transition at the middle of the bit provides synchronization. A) Manchester B) differential Manchester C) both (a) and (b) D) neither (a) nor (b) 137. The ________ mode provides synchronization for the entire stream of bits must. In other words, it guarantees that the data arrive at a fixed rate. A) isochronous B) synchronous C) asynchronous D) none of the above 138. The idea of RZ and the idea of NRZ-I are combined into the ________ scheme. A) Manchester B) differential Manchester C) both (a) and (b) D) neither (a) nor (b) 139. In decoding a digital signal, the receiver calculates a running average of the received signal power, called the _______. A) base B) line C) baseline D) none of the above 140. In _________ transmission, we send bits one after another without start or stop bits or gaps. It is the responsibility of the receiver to group the bits. A) synchronous B) asynchronous C) isochronous D) none of the above 141. ______ finds the value of the signal amplitude for each sample; ____ finds the change from the previous sample. A) DM; CM B) DM; PCM C) PCM; DM D) none of the above 142. ______ substitutes four consecutive zeros with 000V or B00V.

A) HDB3 B) B4B8 C) B8ZSf D) none of the above 143. The ______ scheme uses three levels (+V, 0, and -V) and three transition rules to move between the levels. A) 4B5B B) MLT-3 C) 2B1Q D) none of the above 144. While there is (are) only _____ way(s) to send parallel data, there is (are) _____ subclass(es) of serial transmission. A) one; two B) one; three C) two; three D) none of the above 145. Which quantization level results in a more faithful reproduction of the signal? A) 2 B) 8 C) 16 D) 32 146. A _________ digital signal includes timing information in the data being transmitted. A) self-synchronizing B) self-transmitted C) self-modulated D) none of the above 147. 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) 148. The first step in PCM is ________. A) quantization B) sampling C) modulation D) none of the above 149. _______ encoding has a transition at the middle of each bit. A) Manchester B) Differential Manchester C) RZ D) All the above 150. In ______ transmission, we send 1 start bit (0) at the beginning and 1 or more stop bits (1s) at the end of each byte. A) synchronous B) asynchronous C) isochronous D) none of the above 151. In _______ transmission, bits are transmitted simultaneously, each across its own wire. A) Asynchronous serial B) Synchronous serial C) Parallel D) (a) and (b) 152. Which encoding method uses alternating positive and negative values for 1s?

A) AMI B) RZ C) NRZ-I D) Manchester 153. The data rate is sometimes called the ___ rate. A) bit B) baud C) signal D) none of the above 154. _______ provides redundancy to ensure synchronization and inherent error detection. A) Line coding B) Block coding C) Scrambling D) None of the above 155. 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) 156. Two common scrambling techniques are ________. A) B8ZS and HDB3 B) AMI and NRZ C) NRZ and RZ D) Manchester and differential Manchester 157. ___________ conversion involves three techniques: line coding, block coding, and scrambling. A) Analog-to-analog B) Analog-to-digital C) Digital-to-analog D) Digital-to-digital 158. The _____ scheme uses data patterns of size 2 and encodes the 2-bit patterns as one signal element belonging to a four-level signal. A) MLT-3 B) 4B5B C) 2B1Q D) none of the above 159. In _____, the level of the voltage determines the value of the bit. A) NRZ-I B) NRZ-L C) both (a) and (b) D) neither (a) nor (b) 160. ________ is the process of converting digital data to a digital signal. A) Line coding B) Block coding C) Scrambling D) None of the above 161. In a _____ scheme, all the signal levels are on one side of the time axis, either above or below. A) unipolar B) polar C) bipolar D) all of the above 1.

In ________, the amplitude of the carrier signal is varied to create signal elements. Both fre quency and phase remain constant

A) PSK B) ASK C) FSK D) QAM 163.How many carrier frequencies are used in BPSK? A) 0 B) 1 C) 2 D) none of the above 164.The constellation diagram of 16-QAM has ______ dots. A) 4 B) 8 C) 16 D) none of the above 165.AM and FM are examples of ________ conversion. A) analog-to-analog B) digital-to-digital C) analog-to-digital D) digital-to-analog 166.The Federal Communications Commission (FCC) allows ______ kHz for each FM station. A) 20 B) 100 C) 200 D) none of the above 167.Analog-to-analog conversion is needed if the available bandwidth is _______. A) band-pass B) low-pass C) either (a) or (b) D) neither (a) nor (b) 168.In _____ transmission, the frequency of the carrier signal is modulated to follow the changing voltage level (amplitude) of the modulating signal. The peak amplitude and phase of the ca rrier signal remain constant, but as the amplitude of the information signal changes, the frequency of the carrier changes correspondingly. A) AM B) FM C) PM D) none of the above 169.How many carrier frequencies are used in QPSK? A) 0 B) 2 C) 1 D) none of the above 170.Which of the following is not a digital-to-analog conversion? A) FSK B) ASK C) AM D) PSK 171. _______ conversion is the process of changing one of the characteristics of an analog signal based on the information in the digital data. A) Analog-to-analog B) Digital-to-digital C) Digital-to-analog D) Analog-to-digital

172.If the baud rate is 400 for a QPSK signal, the bit rate is ________ bps. A) 100 B) 400 C) 800 D) 1600 173.In ________, the phase of the carrier is varied to represent two or more different signal elements. Both peak amplitude and frequency remain constant. A) PSK B) FSK C) ASK D) QAM 174.Which of the following is not an analog-to-analog conversion? A) QAM B) AM C) PM D) FM 175.How many carrier frequencies are used in BASK? A) 0 B) 1 C) 2 D) none of the above 176.Quadrature amplitude modulation (QAM) is a combination of ___________. A) PSK and FSK B) ASK and FSK C) ASK and PSK D) none of the above 177.In _________, the frequency of the carrier signal is varied to represent data. Both peak amplitude and phase remain constant. A) ASK B) FSK C) PSK D) QAM 178.If the bit rate for an ASK signal is 1200 bps, the baud rate is ________. A) 1200 B) 600 C) 400 D) 300 179.The constellation diagram of BPSK has ______ dots. A) 0 B) 1 C) 2 D) none of the above 180.The constellation diagram of QPSK has ______ dots. A) 4 B) 2 C) 1 D) none of the above 181.In _______, the peak amplitude of one signal level is 0; the other is the same as the amplitude of the carrier frequency. A) OOK B) PSK C) FSK D) none of the above

182.If the bit rate for a 16-QAM signal is 4000 bps, what is the baud rate? A) 1200 B) 1000 C) 400 D) 300 183.ASK, PSK, FSK, and QAM are examples of ________ conversion. A) analog-to-analog B) digital-to-digital C) analog-to-digital D) digital-to-analog 184.If the bit rate for an FSK signal is 1200 bps, the baud rate is ________. A) 1200 B) 600 C) 400 D) 300 185.The constellation diagram of BASK has ______ dots. A) 0 B) 1 C) 2 D) none of the above 186.The Federal Communications Commission (FCC) allows ______kHz for each AM station. A) 20 B) 10 C) 5 D) none of the above 187.How many carrier frequencies are used in BFSK? A) 2 B) 1 C) 0 D) none of the above 188.In _____ transmission, the phase of the carrier signal is modulated to follow the changing voltage l evel (amplitude) of the modulating signal. A) AM B) FM C) PM D) none of the above 189. _________ conversion is the representation of analog information by an analog signal. A) Analog-to-analog B) Digital-to-digital C) Analog-to-digital D) Digital-to-analog 190.In _____ transmission, the carrier signal is modulated so that its amplitude varies with the changing amplitudes of the modulating signal. A) PM B) FM C) AM D) none of the above 191.In QAM, both ________ of a carrier frequency are varied. A) phase and frequency B) amplitude and phase C) frequency and amplitude D) none of the above 192. ________ uses two carriers, one in-phase and the other quadrature.

A) QAM B) ASK C) FSK D) PSK 193.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) 710 KHz B) 705 KHz C) 700 KHz D) Cannot be determined from given information 194.A constellation diagram shows us the __________ of a signal element, particularly when we are using two carriers (one in-phase and one quadrature). A) amplitude and frequency B) amplitude and phase C) frequency and phase D) none of the above 195.If the baud rate for a 64-QAM signal is 2000, what is the bit rate? A) 12000 B) 1000 C) 400 D) 300 196.The _______ technique uses M different carrier frequencies that are modulated by the source signal. At one moment, the sign modulates one carrier frequency; at the next moment, the signal modulates another carrier frequency. A) DSSS B) FHSS C) FDM D) TDM 197.In synchronous TDM, for n signal sources of the same data rate, each frame contains _______ slots. A) n + 1 B) n - 1 C) 0 to n D) n 198.Which multiplexing technique transmits digital signals? A) WDM B) FDM C) TDM D) None of the above 199.The sharing of a medium and its link by two or more devices is called _______. A) modulation B) multiplexing C) encoding D) line discipline 200. _______ is designed to be used in wireless applications in which stations must be able to share the medium without interception by an eavesdropper and without being subject to jamming from a malicious intruder. A) Multiplexing B) Spread spectrum C) Modulation D) None of the above. 201. ______ is an analog multiplexing technique to combine optical signals. A) WDM B) FDM

C) TDM D) None of the above 202.FDM is an _________technique. A) digital B) analog C) either (a) or (b) D) none of the above 203. ______ can be applied when the bandwidth of a link (in hertz) is greater than the combined bandwidths of the signals to be transmitted. A) TDM B) FDM C) Both (a) or (b) D) Neither (a) or (b) 204.In TDM, the transmission rate of the multiplexed path is usually _______ the sum of the transmission rates of the signal sources. A) equal to B) less than C) greater than D) not related to 205.In a multiplexed system, __ lines share the bandwidth of ____ link. A) 1; n B) n; 1 C) 1; 1 D) n; n 206. _________ utilization is the use of available bandwidth to achieve specific goals. A) Amplitude B) Frequency C) Bandwidth D) None of the above 207. ____ is designed to use the high bandwidth capability of fiber-optic cable. A) WDM B) FDM C) TDM D) None of the above 208.We can divide ____ into two different schemes: synchronous or statistical. A) WDM B) TDM C) FDM D) none of the above 209.In ________ TDM, each input connection has an allotment in the output even if it is not sending data. A) isochronous B) statistical C) synchronous D) none of the above 210.In ________ TDM, slots are dynamically allocated to improve bandwidth efficiency. A) isochronous B) synchronous C) statistical D) none of the above 211.The word ______ refers to the portion of a _______ that carries a transmission. A) line; channel B) channel; link C) link; channel

D) line; link 212.Which multiplexing technique shifts each signal to a different carrier frequency? A) FDM B) TDM C) Both (a) and (b) D) None of the above 213.Which multiplexing technique transmits analog signals? A) WDM B) TDM C) FDM D) (a) and (c) 214. ________ is the set of techniques that allows the simultaneous transmission of multiple signals across a single data link. A) Demodulating B) Multiplexing C) Compressing D) None of the above 215. ________ can be achieved by using multiplexing; ______ can be achieved by using spreading. A) Privacy and antijamming; efficiency B) Privacy and efficiency; antijamming C) Efficiency; privacy and antijamming D) Efficiency and antijamming; privacy 216.The ______ technique expands the bandwidth of a signal by replacing each data bit with n bits. A) DSSS B) FHSS C) FDM D) TDM 217. ________ is a digital process that allows several connections to share the high bandwidth of a link. A) WDM B) TDM C) FDM D) None of the above 218. _______ is a digital multiplexing technique for combining several low-rate channels into one high-rate one. A) WDM B) TDM C) FDM D) None of the above 219.In ________, we combine signals from diff erent sources to fit into a la rger bandwidth. A) line coding B) block coding C) spread spectrum D) none of the above 220.Which multiplexing technique involves signals composed of light beams? A) WDM B) FDM C) TDM D) none of the above 221.When the angle of incidence is _______ the critical angle, the light beam bends along the interface. A) less than B) equal to C) more than D) none of the above

222.Transmission media lie below the _______ layer. A) application B) transport C) network D) physical 223. _________ cable consists of an inner copper core and a second conducting outer sheath. A) Twisted-pair B) Shielded twisted-pair C) Coaxial D) Fiber-optic 224. __________ consists of a central conductor and a shield. A) Twisted-pair B) Coaxial C) Fiber-optic D) none of the above 225. _______ cable can carry signals of higher frequency ranges than _______ cable. A) Coaxial; twisted-pair B) Twisted-pair; fiber-optic C) Coaxial; fiber-optic D) none of the above 226. _________ are used for cellular phone, satellite, and wireless LAN communications. A) Radio waves B) Infrared waves C) Microwaves D) none of the above 227.The inner core of an optical fiber is _______ in composition. A) copper B) glass or plastic C) bimetallic D) liquid 228.What is the major factor that makes coaxial cable less susceptible to noise than twisted-pair cable? A) insulating material B) inner conductor C) diameter of cable D) outer conductor 229.Signals with a frequency below 2 MHz use _______ propagation. A) line-of-sight B) sky C) ground D) none of the above 230.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 231. ________ cable consists of two insulated copper wires twisted together. A) Twisted-pair B) Coaxial C) Fiber-optic D) none of the above 232.In fiber optics, the signal is _______ waves. A) radio B) light

C) infrared D) very low-frequency 233.Signals with a frequency above 30 MHz use _______propagation. A) line-of-sight B) sky C) ground D) none of the above 234.A parabolic dish antenna is a(n) _______ antenna. A) unidirectional B) bidirectional C) omnidirectional D) horn 235.A(n) _______ medium provides a physical conduit from one device to another. A) unguided B) guided C) either (a) or (b) D) none of the above 236. ________ cable is used for voice and data communications. A) Twisted-pair B) Coaxial C) Fiber-optic D) none of the above 237.Signals with a frequency between 2 MHz an d 30 MHz use _______ propagation. A) ground B) line-of-sight C) sky D) none of the above 238.Transmission media are usually categorized as _______. A) determinate or indeterminate B) fixed or unfixed C) guided or unguided D) metallic or nonmetallic 239. ________ are used for short-range communications such as those between a PC and a peripheral device. A) Radio waves B) Infrared waves C) Microwaves D) none of the above 240. _________ media transport electromagnetic waves without the use of a physical conductor. A) Guided B) Unguided C) Either (a) or (b) D) None of the above 241. ________ cables are composed of a glass or plastic inner core surrounded by cladding, all encased in an outside jacket. A) Twisted-pair B) Coaxial C) Fiber-optic D) none of the above 242.Which of the following primarily uses guided media? A) radio broadcasting B) satellite communications C) local telephone system D) cellular telephone system

243.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) criticism D) incidence 244.Which of the following is not a guided medium? A) fiber-optic cable B) coaxial cable C) twisted-pair cable D) atmosphere 245.Microwaves are _________. A) omnidirectional B) bidirectional C) unidirectional D) none of the above 246. ________ cables carry data signals in the form of light. A) Twisted-pair B) Coaxial C) Fiber-optic D) none of the above 247.Radio waves are _________. A) unidirectional B) omnidirectional C) bidirectional D) none of the above 248.In a fiber-optic cable, the signal is propagated along the inner core by _______. A) refraction B) reflection C) modulation D) none of the above 249.Packet-switched networks can also be divided into ______subcategories: virtual-circuit networks and datagram networks. A) five B) three C) two D) four 250.In __________, each packet is treated independently of all others. A) circuit switching B) datagram switching C) frame switching D) none of the above 251.Based on the Clos criteria, if N = 200, then k must be equal to or greater than ______. A) 19 B) 21 C) 31 D) 41 252.In _________, resources are allocated on demand. A) circuit switching B) datagram switching C) frame switching D) none of the above 253.In _______ switching, the paths in the circuit are separated from one another spatially.

A) time-division B) two-dimensional C) space-division D) three-dimensional 254.In a ________ network, two types of addressing are involved: global and local. A) datagram B) virtual-circuit C) circuit-switched D) none of the above 255.In a three-stage space division switch, if N = 200, the number of crosspoints is ______. A) 40,000 B) less than 40,000 C) greater than 40,000 D) greater than 100,000 256.A ________ network is made of a set of switches connected by physical links, in which each link is divided into n channels. A) circuit-switched B) line-switched C) frame-switched D) none of the above 257.In a banyan switch, for 8 inputs and 8 outputs, we have _____ microswitches at each stage. A) 2 B) 3 C) 4 D) 8 258.In _________, there is no resource allocation for a packet. A) circuit switching B) datagram switching C) frame switching D) none of the above 259.A _________ network is a cross between a circuit -switched network and a datagram network. It has some characteristics of both. A) packet-switched B) frame-switched C) virtual-circuit D) none of the above 260.The most popular technology in time-division switching is c alled the _________. A) TSI B) STI C) ITS D) none of the above 261.A switched WAN is normally implemented as a _______ network. A) virtual-circuit B) datagram C) circuit-switched D) none of the above 262.We can say that a packet switch has _______ types of components. A) four B) three C) two D) none of the above 263.In a one-stage space division switch, if N = 200, the number of crosspoints is ______. A) 20,000

B) 40,000 C) 30,000 D) 10,000 264.In a banyan switch, for 8 inputs and 8 outputs, we have _____ stages. A) 2 B) 3 C) 4 D) 8 265.A switch in a datagram network uses a routing table that is based on the ______ address. A) destination B) source C) local D) none of the above 266.Traditionally, _____ methods of switching have been important. A) six B) five C) four D) three 267.The network layer in the Internet is designed as a __________ network. A) circuit-switched B) datagram C) virtual-circuit D) none of the above 268.A ________ switch combines space-division and time-division technologies to take advan tage of the best of both. A) SSS B) TST C) TTT D) none of the above 269.In _______, the resources need to be reserved during the setup phase; the resources remain dedicated for the entire duration of data transfer phase until the teardown phase. A) frame switching B) datagram switching C) circuit switching D) none of the above 270.Based on the Clos criteria, if N = 200, then n must be equal to or greater than ____. A) 40 B) 30 C) 20 D) 10 271.Circuit switching takes place at the ________ layer. A) physical B) data line C) network D) transport 272.A ________ switch combines crossbar switches in several (normally three) stages. A) multiple path B) multiple crossbar C) multistage D) none of the above 273.In _______ there are no setup or teardown phases. A) circuit switching B) datagram switching

C) frame switching D) none of the above 274.We can divide today's networks into ____ broad categories. A) five B) four C) three D) two 275.A ________ switch is a multistage switch with microswitches at each stage that route the packets based on the output port represented as a binary string. A) TSI B) banyan C) crossbar D) none of the above 276.The _______ address in the header of a packet in a datagram network normally remains the same during the entire journey of the packet. A) destination B) source C) local D) none of the above 277.Based on the Clos criteria, if N = 200, then the minimum number of crosspoints is greater than or equal to  _______. A) 42,000 B) 20,000 C) 18,000 D) 15,200 278.The simplest type of switching fabric is the ______ switch. A) crossbar B) crosspoint C) TSI D) STS 279.To use a cable network for data transmission, we need two key devices: a ______ and a _________ A) CT; CMTS B) CM; CMTS C) CM; CMS D) none of the above 280.A local telephone network is an example of a _______ network. A) packet-switched B) message-switched C) circuit-switched D) none of the above 281.A traditional cable TV network transmits signals ______. A) downstream B) upstream C) upstream and downstream D) none of the above 282.The traditional cable TV system used ________cable end to end. A) twisted-pair B) fiber-optic C) coaxial D) none of the above 283.The telephone network is made of ______ major components. A) 4 B) 3

C) 2 D) none of the above 284.Data from a computer are _______; the local loop handles _______ signals. A) analog; analog B) digital; digital C) digital; analog D) analog; digital 285.The original telephone network, which is referred to as the plain old telephone system (POTS), was an  ________ system. A) analog B) digital C) digital as well as analog D) none of the above 286.The protocol that is used for signaling in the telephone network is called ______. A) SSS B) SS7 C) POP D) none of the above 287. _______technology is a set of technologies developed by the telephone companies to provide high data rate transmission. A) LDS B) ASL C) DSL D) none of the above 288.The local loop has _______ cable that connects the subscriber telephone to the nearest end office. A) fiber-optic B) coaxial C) twisted-pair D) none of the above 289.The second generation of cable networks is call ed a(n) _________ network. A) HCF B) HFC C) CFH D) none of the above 290.The largest portion of the bandwidth for ADSL carries _______. A) upstream data B) downstream data C) control data D) voice communication 291. _______ is suitable for businesses that require comparable upstream and downstream data rates. A) SDSL B) ADSL C) VDSL D) (b) and (c) 292.The carrier that handles intra-LATA services is called a (n) _____ . A) IXC B) LEC C) POP D) none of the above 293.DMT is a modulation technique that combines elements o f _______ and _______. A) FDM; QAM B) FDM; TDM C) PSK; FSK

D) QDM; QAM 294.The carrier that handles inter-LATA services is called a (n) _______. A) IXC B) LEC C) POP D) none of the above 295.The modern telephone network is now ________. A) digital B) digital as well as analog C) analog D) none of the above 296.In an HFC network, the upstream data are modulated using the _______ modulation technique. A) ASK B) PCM C) QAM D) QPSK 297. _______ was designed as an alternative to the T-1 line. A) ADSL B) HDSL C) VDSL D) SDSL 298.HDSL encodes data using _______. A) 2B1Q B) 1B2Q C) 4B/5B D) 6B/8T 299.In an HFC network, the downstream data are modulated using the _______ modulation technique. A) PCM B) QAM C) PSK D) ASK 300.Another name for the cable TV offic e is the _______. A) head end B) combiner C) fiber node D) splitter 301.The term modem is a composite word that refers to the two functional entities that make up the device: a signal _______ and a signal _______. A) demodulator; modulator B) modulator; demodulator C) modern; demo D) none of the above 302.The two most common digital services are ________ service and ______. A) switched/56; DDS B) switched/56; switched/64 C) DDS; switched 64 D) leased; out-of-band 303.The United States is divided into many _______. A) IXCs B) LECs C) LATAs D) none of the above 304.The standard for data transmission over an H FC network is called _______.

A) ADSL B) CMTS C) DOCSIS D) MCNS 305.In ________signaling, a portion of the bandwidth is used for signaling and another portion for data. A) mixed B) in-band C) out-of-band D) none of the above 306.Telephone companies provide two types of analog services: analog _______ services and analog  _____services. A) leased; out-of-band B) out-of-band; in-band C) switched; in-band D) switched; leased 307.The HFC network uses _______ cable. A) coaxial B) twisted-pair C) fiber-optic D) a combination of (a) and (c) 308.In ______signaling, the same circuit is used for both signaling and data. A) mixed B) out-of-band C) in-band D) none of the above 309.Most popular modems available are based on the ________standards. A) X-series B) V-series C) VX-series D) none of the above 310.Checksums use _________ arithmetic. A) one's complement arithmetic B) two's complement arithmetic C) either (a) or (b) D) none of the above 311.The checksum of 1111 and 1111 is _________. A) 0000 B) 1111 C) 1110 D) 0111 312.In modulo-11 arithmetic, we use only the integers in the range ______, inclusive. A) 1 to 10 B) 0 to 10 C) 1 to 11 D) none of the above 313.In cyclic redundancy checking, the divisor is _______ the CRC. A) one bit less than B) one bit more than C) The same size as D) none of the above 314.The ________ between two words is the number of differences between corresponding bits. A) Hamming rule B) Hamming code

C) Hamming distance D) none of the above 315.The _______ of a polynomial is the highest power in the polynomial. A) range B) power C) degree D) none of the above 316.In modulo-2 arithmetic, __________ give the same results. A) addition and subtraction B) addition and multiplication C) addition and division D) none of the above 317.In cyclic redundancy checking, what is the CRC? A) The quotient B) The dividend C) The divisor D) The remainder 318.Which error detection method consists of just one redundant bit per data unit? A) CRC B) Checksum C) Simple parity check D) Two-dimensional parity check 319.In _____ coding, we divide our message into blocks, each of k bits, called ___. A) block; blockwords B) block; datawords C) linear; datawords D) none of the above 320.A _____ error means that two or more bits in the data unit have changed. A) burst B) double-bit C) single-bit D) none of the above 321.Adding 1 and 1 in modulo-2 arithmetic results in _________. A) 0 B) 1 C) 2 D) none of the above 322.In ________ error correction, the receiver corrects errors without requesting retransmission. A) onward B) forward C) backward D) none of the above 323.If the Hamming distance between a dataword and the corresponding codeword is three, there are _____ bits in error. A) 5 B) 4 C) 3 D) none of the above 324.A simple parity-check code can detect __________ errors. A) an odd-number of B) an even-number of C) two D) no errors

325.The Hamming distance between equal codewords is _________. A) 0 B) 1 C) n D) none of the above 326.In a linear block code, the _______ of any two valid codewords creates another valid codeword. A) ANDing B) XORing C) ORing D) none of the above 327.In ________ error correction, the receiver asks the sender to send the da ta again. A) forward B) backward C) retransmission D) none of the above 328.We can divide coding schemes into two b road categories: ________ and ______coding. A) linear; nonlinear B) block; convolution C) block; linear D) none of the above 329.In modulo-2 arithmetic, we use only ______. A) 1 and 2 B) 0 and 1 C) 0 and 2 D) none of the above 330.To guarantee correction of up to 5 errors in all cases, the minimum Hamming distance in a block code must be ________. A) 11 B) 6 C) 5 D) none of the above 331.The _____of errors is more difficult than the ______. A) detection; correction B) correction; detection C) creation; correction D) creation; detection 332.In block coding, if k =2 and n =3, we have _______ invalid codewords. A) 4 B) 8 C) 2 D) none of the above 333.The checksum of 0000 and 0000 is __________. A) 0000 B) 1111 C) 0111 D) 1110 334.In one's complement arithmetic, if positive 7 is 0111, then negative 7 is ________. A) 1101 B) 1000 C) 1111 D) none of the above 335.In block coding, if n = 5, the maximum Hamming distance between two codewords is ________. A) 5

B) 3 C) 2 D) none of the above 336.Which error detection method uses one's complement arithmetic? A) Checksum B) CRC C) Simple parity check D) Two-dimensional parity check 337.The divisor in a cyclic code is normally called the _________. A) redundancy B) degree C) generator D) none of the above 338.In modulo-2 arithmetic, we use the ______ operation for bo th addition and subtraction. A) OR B) XOR C) AND D) none of the above 339.We add r redundant bits to each block to make the length n = k + r. The resulting n-bit blocks are called  _________. A) codewords B) datawords C) blockwords D) none of the above 340.To guarantee the detection of up to 5 errors in all cases, the minimum Hamming distance in a block code must be _______. A) 11 B) 5 C) 6 D) none of the above 341.A generator that contains a factor of ____ can detect all odd-numbered errors. A) x B) 1 C) x + 1 D) none of the above 342. _______codes are special linear block codes with one extra property. If a codeword is rotated, the result is another codeword. A) Convolution B) Cyclic C) Non-linear D) none of the above 343.The Hamming distance between 100 and 001 is ________. A) 0 B) 1 C) 2 D) none of the above 344.In Go-Back-N ARQ, if 5 is the number of bits for the sequence number, then the maximum size of the receive window must be _____. A) 1 B) 15 C) 16 D) 31

345.In Go-Back-N ARQ, if frames 4, 5, and 6 are received successfully, the receiver may send an ACK _______ to the sender. A) 6 B) 7 C) 5 D) any of the above 346.The Stop-And-Wait ARQ, Go-Back-N ARQ, and the Selective Repeat ARQ are for ______ channels. A) noiseless B) noisy C) either (a) or (b) D) neither (a) nor (b) 347.The _________Protocol, adds a simple error control mechanism to the _______Protocol. A) Selective Repeat ARQ; Go-Back-N ARQ B) Go-Back-N ARQ; Stop-and-Wait C) Stop-and-Wait ARQ; Stop-and-Wait D) none of the above 348.In PPP, the ________ is responsible for establishing, maintaining, configuring, and terminating links. A) PAP B) CHAP C) LCP D) NCP 349.HDLC is an acronym for _______. A) Half-duplex digital link combination B) Host double-level circuit C) High-duplex line communication D) High-level data link control 350.In Selective Repeat ARQ, if 5 is the number of bits for the sequence number, then the maximum size of the receive window must be _____. A) 1 B) 15 C) 16 D) 31 351.In Go-Back-N ARQ, if 5 is the number of bits for the sequence number, then the maximum size of the send window must be _____. A) 1 B) 15 C) 16 D) 31 352.In Stop-and-Wait ARQ, the a cknowledgment number always announces in ______ arithmetic the sequence number of the next frame expected. A) modulo-m B) modulo-2 C) modulo-4 D) none of the above 353.In Selective Repeat ARQ, if 5 is the number of bits for the sequence number, then the maximum size of the send window must be _____. A) 1 B) 15 C) 16 D) 31 354. _______ control refers to a set of procedures used to restrict the amount of data that the sender can send before waiting for acknowledgment. A) Flow

B) Error C) Transmission D) none of the above 355.In the Go-Back-N Protocol, if the size of the sequence number field is 8, the sequence numbers are in  ________ arithmetic, A) modulo-256 B) modulo- 8 C) modulo-2 D) none of the above 356. ______ control refers to methods of error detection and correction. A) Flow B) Error C) Transmission D) none of the above 357.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 64 358.Both Go-Back-N and Selective-Repeat Protocols use a _________. A) sliding window B) sliding frame C) sliding packet D) none of the above 359.In _________, the configuration is balanced. The link is point-to-point, and each station can function as a primary and a secondary. A) ARM B) ABM C) NBM D) NRM 360.Byte stuffing means adding a special by te to the data section of the frame when there is a character with the same pattern as the ______. A) trailer B) flag C) header D) none of the above 361.The ______ Protocol has neither flow nor error control. A) Selective-Repeat ARQ B) Go-Back-N ARQ C) Stop-and-Wait D) Simplest 362.The most common protocol for point-to-point access is the Point-to-Point Protocol (PPP), which is a  _________protocol. A) byte-oriented B) bit-oriented C) character-oriented D) none of the above 363.For Stop-and-Wait ARQ, for 10 data packets sent, _______ acknowledgments are needed. A) less than 10 B) more than 10 C) exactly 10 D) none of the above 364. _________framing uses two categories of protocols: character-oriented and bit-oriented.

A) Standard B) Fixed-size C) Variable-size D) None of the above 365. _______ control refers to a set of procedures used to restrict the amount of data that the sender can send before waiting for acknowledgment. A) Flow B) Error C) Transmission D) none of the above 366.In a ________ protocol, the data section of a frame is a sequence of characters. A) bit-oriented B) character-oriented C) either (a) or (b) D) none of the above 367.In _______ framing, there is no need f or defining the boundaries of frames. A) standard B) fixed-size C) variable-size D) none of the above 368.The _______Protocol has both flow control and error control. A) Stop-and-Wait B) Selective-Repeat ARQ C) Go-Back-N ARQ D) both (b) and (c) 369.In _________, the station configuration is unbalanced. We have one primary station and multiple secondary stations. A) ARM B) NBM C) NRM D) ABM 370.In a _________ protocol, the data section of a frame is a sequence of bits. A) bit-oriented B) byte-oriented C) either (a) or (b) D) none of the above 371.In ________ framing, we need a delimiter (flag) to define the boundary of two frames. A) standard B) fixed-size C) variable-size D) none of the above 372.High-level Data Link Control (HDLC) is a _______ protocol for communication over point-to-point and multipoint links. A) byte-oriented B) bit-oriented C) character-oriented D) none of the above 373.Bit stuffing means adding an extra 0 to the data section of the frame when there is a sequence of bits with the same pattern as the ________. A) trailer B) flag C) header D) none of the above

374.In the _________Protocol, if no acknowledgment for a fram e has arrived, we resend all outstanding frames. A) Go-Back-N ARQ B) Selective-Repeat ARQ C) Stop-and-Wait ARQ D) none of the above 375.The Simplest Protocol and the Stop-and-Wait Protocol are for ______ channels. A) noiseless B) noisy C) either (a) or (b) D) neither (a) nor (b) 376.The _______Protocol has flow control, but not error control. A) Selective-Repeat ARQ B) Stop-and-Wait C) Simplest D) Go-Back-N ARQ 377.In Stop-and-Wait ARQ, we use sequence numbers to number the frames. The sequence numbers are based on __________arithmetic. A) modulo-m B) modulo-2 C) modulo-4 D) none of the above 378.In the _____ Protocol, the sender sends its frames one after another with no regard to the receiver. A) Simplest B) Selective-Repeat ARQ C) Stop-and-Wait D) Go-Back-N ARQ 379. _________control in the data link layer is based on automatic repeat request, which is the retransmission of data. A) Flow B) Error C) Transmission D) none of the above 380.In PPP, _______ is a three-way hand-shaking authentication protocol in which th e password is kept secret; it is never sent online. A) PAP B) LCP C) NCP D) CHAP 381.In PPP, ________ is a simple a uthentication procedure with a two-step process: A) CHAP B) PAP C) LCP D) NCP 382.In the _________ protocol we avoid unnecessary transmission by sending only frames that are corrupted. A) Selective-Repeat ARQ B) Stop-and-Wait ARQ C) Go-Back-N ARQ D) none of the above 383.In ________ protocols, we use ________. A) byte-oriented; bit stuffing B) bit-oriented; bit stuffing C) character-oriented; bit stuffing

D) none of the above 384.In the _____ Protocol, the sender sends one frame, stops until it receives confirmation from the receiver, and then sends the next frame. A) Simplest B) Stop-and-Wait C) Selective-Repeat ARQ D) Go-Back-N ARQ 385.Stop-and-Wait ARQ is a special case of Go-Back-N ARQ in which the size of the send window is ___. A) 1 B) 2 C) 8 D) none of the above 386.ARQ stands for _______. A) Acknowledge repeat request B) Automatic retransmission request C) Automatic repeat quantization D) Automatic repeat request 387. _______ in the data link layer separates a message from one source to a destination, or from other messages going from other sources to other destinations. A) Controlling B) Framing C) Digitizing D) none of the above 388.Data link control deals with the design a nd procedures for ______ communication. A) node-to-node B) process-to-process C) host-to-host D) none of the above 389.In _________ protocols, we use ________. A) bit-oriented; character stuffing B) character-oriented; bit stuffing C) character-oriented; byte stuffing D) none of the above