Friday, October 11, 2019

Networking

ITEC325 Final Study Guide True/False Indicate whether the sentence or statement is true or false. ____1. The value of layers in the OSI reference model is that it divides networking into a series of tasks, and then illustrates how those tasks relate to each other. ____2. When transmitting with FHSS, if interference is encountered on a particular frequency then that part of the signal will be retransmitted on the previous frequency of the hopping code. ____3. Increasing the speed of the WLAN will cause shorter delays in waiting for reflections. ____4. Because wireless technology has advanced at such a rapid pace, the earliest WLANs are now essentially obsolete. ____5. Of the 52 subchannels, 32 are used for standard transmissions and 20 are used for FEC transmissions. ____6. When an ESS is installed it is desirable to configure the areas of coverage much like cells in a cellular telephone system. ____7. The first major function of the MAC layer involves defining procedures for a wireless device to discover the WLAN. ____8. Wireless authentication involves a user logging on to the access point. ____9. CSMA/CA eliminates the possibility of collisions. ____10. A home agent is a forwarding mechanism that keeps track of where the mobile computer is located. ____11. Wireless access to network resources can improve the quality and productivity of meetings. ____12. Early adopters of wireless LANs were sometimes called â€Å"racehorses†. ____13. Several vendors are working on comprehensive network management solutions that integrate wireless networks into the same deployment, operations, and management as a wired network. ____14. When considering the number of users who will be associated with an access point, it is only necessary to count the number of users, not the type of work they do. ___15. Establishing and staffing an internal help desk is one of the most effective means of support. ____16. It is important to evaluate the placement of the access points and antennas throughout the proposed site in order to meet the design goals. ____17. The most common type of antenna for a WLAN is an semi-directional antenna, also known as a dipole antenna. ____18. A drawback of spectrum analyzers is that the information is displayed in graphical form and not as raw data. ____19. The industry-standard form for site survey documentation is IEEE 802. 11D. ____20. The first step in collecting RF information is to position the access point in what may appear to be the most logical location. Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. ____21. What is the top layer of the OSI reference model? a. | application| c. | physical| b. | presentation| d. | transport| ____22. Which layer of the OSI reference model permits the devices on the network to hold ongoing communications across the network? a. | presentation| c. | transport| b. | session| d. | network| ____23. ___ signals by nature transmit on only one frequency or a very narrow portion of the frequencies. a. | Broadband| c. | Radio| b. | Computer| d. | Heat| ____24. What is a disadvantage of narrowband transmissions? a. | requires a complicated algorithm| c. | expensive to implement| b. | not well regulated| d. | interference from another radio signal| ____25. When was the concept used by FHSS technology developed? a. | during World War I| c. | in the 1960s| b. | during World War II| d. | in the 1980s| ____26. In FHSS, the amount of time needed to move from one frequency to another is the ____ time. . | dwell| c. | lift| b. | switch| d. | hop| ____27. According to FCC regulations, all FHSS systems in the 900 MHz band must change frequencies through 50 channels and cannot spend more than ____ on one frequency each 20 seconds. a. | 20 milliseconds| c. | 400 milliseconds| b. | 30 milliseconds| d. | 1 second| ____28. Bluetooth divides the 2. 4 GHz frequency into ____ different frequencies spaced 1 GHz apart. a. | 52| c. | 79| b. | 68| d. | 93| ____29. ____ is not part of a frame. a. | Length| c. | Channel| b. | Parity| d. | Data| ____30. How does OFDM work? a. signals are broken up and the parts are sent in parallel| b. | the same signal is sent on multiple channels| c. | one signal is sent twice on the same channel| d. | a signal is sent over a wired network at the same time as the wireless network| ____31. IEEE has divided the ____ layer into two sublayers: Logical Link Control (LLC) and Media Access Control (MAC). a. | Physical| c. | Transport| b. | Data Link| d. | Session| ____32. The Physical Layer Convergence Procedure (PLCP) standards for 802. 11b are based on ____. a. | DSSS| c. | OFDM| b. | FHSS| d. | PYS| ____33. The 802. 1b standard specifies ____ frequencies that can be used, beginning at 2. 412 GHz. a. | 4| c. | 14| b. | 10| d. | 30| ____34. The ____ coding technique consists of a set of 64 8-bit code words. a. | chipping| c. | Barker| b. | fixed scramble| d. | complementary code keying| ____35. The ____ field of an 802. 11a frame consists of 10 repetitions of a short training sequence signal and two repetitions of a long training sequence signal. a. | Rate| c. | Synchronization| b. | Service| d. | Parity| ____36. A BSS is ____. a. | a group of wireless devices that is served by a single access point| b. a unique identifier| c. | a geographical area where wireless devices reside | d. | two or more networks that are connected through a common distribution system| ____37. What is the minimum number of BSS networks required to form an ESS? a. | 0| c. | 2| b. | 1| d. | 10| ____38. All frames contain the MAC address of the source and destination device, a frame sequence number, and a frame ____ used for error detection. a. | unit| c. | sum| b. | flag| d. | check sequence| ____39. The ____ field appears first in a management frame. a. | Frame control| c. | Destination address| b. | Duration| d. | BSSID| ___40. When an AP accepts or rejects a wireless device it sends a(n) ____ frame. a. | association request| c. | disassociation| b. | association response| d. | reassociation| ____41. In an infrastructure network the beacon interval is normally set to ____ ms, although it can be modified. a. | 1| c. | 100| b. | 10| d. | 1000| ____42. What is the default authentication method according to the 802. 11 standard? a. | basic| c. | shared key| b. | open system| d. | priv ate key| ____43. What is the first step in shared key authentication? a. | AP encrypts challenge text and sends it to wireless device| b. wireless device encrypts challenge text and sends it to AP| c. | AP sends wireless device an authentication frame that contains a block of text known as the challenge text| d. | wireless device sends an authentication frame to the AP| ____44. Following authentication, if the access point accepts the wireless device, it reserves memory space in the AP and establishes a(n) ____ ID for it. a. | association| c. | member| b. | device| d. | authentication| ____45. Why is CSMA/CD unsuitable for wireless networks? a. | Hidden node problem| c. | difficult to synchronize backoff times| b. difficult to detect collisions| d. | Both A and B| ____46. The 802. 11 standard provides an option that can be used when collisions occur due to a hidden node. That option is known as ____. a. | virtual node detection| c. | virtual carrier sensing| b. | node collision prot ocol| d. | hidden node detection| ____47. The RTS/CTS protocol is especially taxing when ____ data packets are being transmitted. a. | short| c. | encrypted| b. | long| d. | redirecting| ____48. ____ effectively prevents collisions because every device must wait until it receives permission before it can transmit. a. | CSMA/CD| c. Polling| b. | CSMA/CA| d. | Fragmentation| ____49. The ____ draft defines a superset of features that is intended to provide QoS over WLANs. a. | 802. 11a| c. | 802. 11e| b. | 802. 11b| d. | 802. 11g| ____50. An access point sends out a beacon frame containing a ____ identifying the stations that have buffered frames waiting at the access point. a. | buffer list| c. | waiting map| b. | traffic indication map| d. | buffered cache| ____51. With MobileIP, the ____ assigns the mobile computer a new (but temporary) IP number. a. | local AP| c. | foreign agent| b. | foreign AP| d. | roamed network| ____52. What do many industry experts believe is the greatest opportunity for business-process improvement at the beginning of the 21st century? a. | access to the Internet from employee’s desks| b. | extending network access to employees who are away from their desks| c. | providing wireless hotspots in rural communities| d. | All of the above| ____53. According to a study conducted by NOP World–Technology, wireless LANs enable users to be connected to network resources ____ additional hours per day. a. | . 5| c. | 1. 75| b. | 1| d. | 2. 5| ____54. Which organization would most likely not benefit from the introduction of a wireless LAN? . | business that is rapidly losing market share and has changed CEOs three times in the last 18 months| b. | business that has captured a niche in the marketplace and currently has no serious competitors| c. | organization that is fighting a fierce battle with its competitors| d. | they would all benefit| ____55. According to NOP-World Technol ogy, ____ percent of end users said that a WLAN improves their quality of life by increasing flexibility and productivity, and saving time. a. | 30| c. | 87| b. | 56| d. | 93| ____56. Intel recommends that once the ROI model is complete, larger organizations should return to step ____. . | 1| c. | 3| b. | 2| d. | 4| ____57. A(n) ____ provides wireless LAN service, for free or for a fee, from a variety of public areas, including coffee shops, public libraries, and airport lounges. a. | wireless gateway| c. | hotspot| b. | infrastructure network| d. | ad hoc network| ____58. Only in areas where low bandwidth is acceptable or an ad hoc wireless network will be used should ____ networks be considered. a. | 802. 11a| c. | 802. 11g| b. | 802. 11b| d. | 802. 11 pre-N| ____59. What is a disadvantage of thin access points? a. | complicated network management| b. | handoff time is increased| c. | very expensive| . | all thin access points and switches are proprietary| ____60. ____ generates t he highest level of interference. a. | Marble| c. | Paper| b. | Bulletproof glass| d. | Metal| ____61. In a 802. 11b network, how many power users should be associated with one access point? a. | 5| c. | 25| b. | 15| d. | 50| ____62. What should you do when electrical alternating current power is not available near the AP location? a. | move it to another location| c. | use a battery| b. | use wireless power| d. | user Power over Ethernet| ____63. ____ is one of the most effective strategies for providing support for a new wireless network. . | Creating formal user support groups| b. | Assigning support to the information technology department| c. | Maintaining a help desk| d. | Outsourcing support to a third party| ____64. In a site survey analyzer, vendors use an algorithm or a lookup table to convert ____ values to dBm, mW, or signal strength percentage. a. | GHz| c. | RSSI| b. | MAC| d. | RFID| ____65. What is a drawback of a spectrum analyzer? a. | information is displayed in g raphical form and not as raw data| b. | information is displayed as raw data, not in graphical form| c. | information only applies to one frequency| d. only made by a single manufacturer and very expensive| ____66. How are business requirements for a WLAN obtained? a. | reading company documentation| c. | interviewing technical staff| b. | interviewing management| d. | Internet research| ____67. What is the best way to gather site-specific documentation? a. | reviewing blueprints| c. | inspecting the site| b. | interviewing management| d. | viewing documentation| ____68. What is the first step in collecting RF information? a. | position the access point| c. | document AP position| b. | note the objects and layout of the room| d. | walk around room to test signal| ___69. What should you be sure to do when collecting RF information? a. | take pictures of your location as you move around| b. | connect to the Internet and download a file to test bandwidth| c. | write down your perceptio n of connection speed| d. | observe the data being displayed by the software measurement tools| ____70. What affects the coverage pattern? a. | wireless protocol| c. | notebook operating system| b. | objects that interfere with the RF signal| d. | skill of person conducting site survey| ____71. The term ____ describes the rate of transmission falling as the device moves farther from the AP. a. coverage pattern| c. | data rate boundaries| b. | packet throughput| d. | RF frequency| ____72. What affects transmission range? a. | distance only| c. | distance and objects in path| b. | objects in path only| d. | wireless protocol| ____73. What provides the greatest source of RF interference? a. | mirror| c. | desk| b. | interior wall| d. | chair| ____74. What type of AP antenna is most commonly used in a site survey? a. | omnidirectional| c. | highly-directional| b. | semi-directional| d. | parabolic| ____75. The ____ setting of a site survey analyzer specifies the AP that will be involved in the test. a. Destination MAC Address| c. | Packet Tx Type| b. | Continuous Link Test| d. | Delay Between Packets| ____76. Why is it important to document existing wired and wireless networks? a. | to examine possible sources of interference| b. | to ensure that the new or expanded wireless LAN will â€Å"dovetail† into what is already in place| c. | to avoid providing overlapping network coverage| d. | to better understand the basic networking needs of the organization| Matching Match each term with the correct statement below. a. | physical layer| f. | direct sequence spread spectrum| b. | channel bonding| g. | quadrature phase shift keying| c. frequency hopping spread spectrum| h. | transport layer| d. | Forward Error Correction| i. | orthogonal frequency division multiplexing| e. | network layer| ____77. uses a range of frequencies that change during the transmission ____78. transmits a secondary copy along with the primary information ____79. sends signals to the netw ork or receives signals from the network ____80. ensures that error-free data is given to the user ____81. sending multiple signals at the same time Match each term with the correct statement below. a. | dynamic rate shifting| f. | frames| b. | digital certificate| g. | contention| c. | scanning| h. roaming| d. | ad hoc mode| i. | polling| e. | reassociation| ____82. segments in a packet ____83. any device can attempt to transmit a message at any time ____84. as a mobile device moves farther away from the AP, the transmission speed decreases ____85. wireless devices communicate directly between themselves ____86. digital documents that associate an individual with a key value ____87. receiving wireless device looking for beacon frames Match each term with the correct statement below. a. | ad hoc| f. | Point-to-multipoint remote wireless bridge| b. | plenum| g. | soft benefits| c. | current network table| h. thin access point| d. | fat access point| i. | hard benefits| e. | ROI| ____ 88. standard measure of the profitability of a project ____89. benefits that are difficult to quantify ____90. management functions of a WLAN such as user authentication, encryption, and access point configuration are included within the AP itself ____91. air handling space above drop ceilings ____92. benefits that can be easily measured or quantified ____93. used to connect multiple LAN segments Match each term with the correct statement below. a. | coverage pattern| f. | network analyzer| b. | spectrum analyzer| g. | transmission range| c. packet throughput| h. | unicast| d. | site survey analyzer| i. | data rate boundary| e. | multicast| ____94. frame is sent from one sender to multiple receivers with a single â€Å"transmit† operation ____95. area in which the signal can be received from the AP ____96. frame is sent from one sender to a single receiver ____97. scans the radio frequency spectrum and provides a graphical display of the results ____98. measurement tool that is specifically designed for conducting a wireless LAN site survey ____99. range of coverage for a specific transmission speed ____100. number of packets sent and received and the data rates for each

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