Certified Wireless Network Professional (CWNA) Quiz

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Questions and Answers
  • 1. 
    What can cause an excessively high VSWR (Voltage Standing Wave Ratio) in a WLAN RFtransmission line?
    • A. 

      Reflected direct current (DC) voltage on the main RF signal line

    • B. 

      An impedance mismatch in the RF cables and connectors

    • C. 

      Attenuation of the RF signal as it travels along the main signal path

    • D. 

      Crosstalk (inductance) between adjacent RF conductors

  • 2. 
    What word describes the bending of an RF signal as it passes through a medium of a varyingdensity from that of free space?
    • A. 

      Reflection

    • B. 

      Diffraction

    • C. 

      Refraction

    • D. 

      Diffusion

    • E. 

      Scattering

  • 3. 
    • A. 

      MAC layer encryption

    • B. 

      Transmitting station’s power source

    • C. 

      Free Space Path Loss

    • D. 

      Transmitting station’s output power

    • E. 

      Temperature in the Fresnel zone

    • F. 

      Receiving station’s radio sensitivity

  • 4. 
    As an RF wave propagates through space, the wave front experiences natural expansion thatreduces its signal strength in an area. What term describes the rate at which this expansionhappens?
    • A. 

      MU-MIMO

    • B. 

      Inverse square law

    • C. 

      Path spread phenomenon

    • D. 

      Fresnel zone thinning

    • E. 

      Ohm’s law

  • 5. 
    Return Loss is the decrease of forward energy in a system when some of the power is beingreflected back toward the transmitter.What will cause high return loss in an RF transmission system, including the radio, cables,connectors and antenna?
    • A. 

      A Voltage Standing Wave Ratio (VSWR) of 1:1

    • B. 

      Cross-polarization of the RF signal as it passes through the RF system

    • C. 

      An impedance mismatch between components in the RF system

    • D. 

      The use of cables longer than one meter in the RF system

    • E. 

      High output power at the transmitter and use of a low-gain antenna

  • 6. 
    What factors are taken into account when calculating the Link Budget of a point-to-point outdoorWLAN bridge link?
    • A. 

      Antenna height

    • B. 

      Transmit antenna gain

    • C. 

      Transmit power

    • D. 

      Operating frequency

  • 7. 
    A WLAN transmitter that emits a 200 mW signal is connected to a cable with 3 dB loss.If the cable is connected to an antenna with 10 dBi gain, what is the EIRP at the antenna element?
    • A. 

      10 dBm

    • B. 

      13 dBm

    • C. 

      20 dBm

    • D. 

      26 dBm

    • E. 

      30 dBm

  • 8. 
    In a long-distance RF link, what statement about Fade Margin is true?
    • A. 

      The Fade Margin of a long-distance radio link should be equivalent to the receiver’s antenna gain.

    • B. 

      A Fade Margin is unnecessary on a long-distance RF link if more than 80% of the first Fresnel zone is clear of obstructions

    • C. 

      Fade Margin is an additional pad of signal strength designed into the RF system to compensate for unpredictable signal fading.

    • D. 

      The Fade Margin is a measurement of signal loss through free space, and is a function of frequency and distance.

  • 9. 
    Which unit of measurement is an absolute unit that is used to quantify power levels on a linearscale?
    • A. 

      DBm

    • B. 

      W

    • C. 

      dB

    • D. 

      mW

    • E. 

      VSWR

  • 10. 
    An 802.11 WLAN transmitter that emits a 50 mW signal is connected to a cable with 3 dB of loss.The cable is connected to an antenna with 16 dBi of gain.What is the EIRP power output?
    • A. 

      1000 mW

    • B. 

      25 mW

    • C. 

      50 mW

    • D. 

      250 mW

    • E. 

      10 mW

  • 11. 
    What is always required to establish a high quality 2.4 GHz RF link at a distance of 3 miles(5 kilometers)?
    • A. 

      Accurate Earth Bulge calculations

    • B. 

      Minimum output power level of 2 W

    • C. 

      Grid antennas at each endpoint

    • D. 

      A Fresnel Zone that is at least 60% clear of obstructions

    • E. 

      A minimum antenna gain of 11 dBi at both endpoints

  • 12. 
    What phrase defines Equivalent Isotropically Radiated Power (EIRP)?
    • A. 

      Reflected power due to an impedance mismatch in the signal path

    • B. 

      The power output from the radio into the RF cable

    • C. 

      The highest RF signal strength that is transmitted from a given antenna

    • D. 

      Power supplied from the transmission line to the antenna input

    • E. 

      The power output from the radio into the RF cable

  • 13. 
    What term describes the effect of increasing the intensity of an RF wave with an antenna byfocusing the energy in a specific direction? 
    • A. 

      Beam Compression

    • B. 

      Distributed Radiation

    • C. 

      Active Amplification

    • D. 

      Passive Gain

    • E. 

      RF Flooding

  • 14. 
    Which antenna types are commonly used by indoor Wi-Fi devices in a MIMO diversityimplementation? (Choose 2)
    • A. 

      Grid

    • B. 

      Dipole

    • C. 

      Patch

    • D. 

      Dish

    • E. 

      Sector

  • 15. 
    What phrase correctly completes the following sentence?When using WMM Power Save operation, a wireless client device ______________. 
    • A. 

      Alternates between awake and dozing, depending on its need to transmit and receive information

    • B. 

      Enters a low-power radio state until it receives a WMM PS-Poll frame from the AP

    • C. 

      Experiences higher throughput and lower latency than when operating in Active mode

    • D. 

      Powers down a subset of MIMO radio chains and transmits information at a slower data rate

    • E. 

      Buffers frames destined to the low-power AP until the AP wakes its radio and begins beaconing again

  • 16. 
    When replacing the antenna of a WLAN device with a similar antenna type that has a higherpassive gain, what antenna characteristic will decrease?
    • A. 

      Range

    • B. 

      Beam width

    • C. 

      Active gain

    • D. 

      Receive sensitivity

    • E. 

      Fresnel Zone size

    • F. 

      Fresnel Zone size

  • 17. 
    What statements about the beamwidth of an RF antenna are true? (Choose 2)
    • A. 

      The lower the gain of an antenna, the more narrow one or both beamwidths become

    • B. 

      The beamwidth patterns on an antenna polar chart indicate the point at which the RF signal stops propagating

    • C. 

      Horizontal and vertical beamwidth are calculated at the points in which the main lobe decreases power by 3 dB.

    • D. 

      Horizontal beamwidth is displayed (in degrees) on the antenna’s Azimuth Chart.

  • 18. 
    What HT technology requires MIMO support on both the transmitter and receiver?
    • A. 

      Spatial multiplexing

    • B. 

      Short guard intervals

    • C. 

      Maximal ratio combining

    • D. 

      Orthogonal Frequency Division Multiplexing

  • 19. 
    ABC Company has just purchased a 6 dBi patch antenna. After performing some tests with the 6 dBi antenna, they have concluded that more antenna gain is needed to cover their outdoor courtyard. When choosing an antenna with higher gain, what other antenna characteristic will also always change?
    • A. 

      Fresnel Zone size

    • B. 

      Beamwidth

    • C. 

      Maximum input power

    • D. 

      Impedance

    • E. 

      VSWR Ratio

  • 20. 
    AP-1 is a 3x3:2 AP. STA-3 is a 3x3:3 client. What is the maximum number of spatial streams thatcan be used for a downlink HT-OFDM transmission from AP-1 to STA-3?
    • A. 

      One spatial stream, because the definition of the AP indicates that it is capable of only one spatial stream.

    • B. 

      Three spatial streams, because the definition of the client indicates that it is capable of only three spatial streams.

    • C. 

      Two spatial streams, because the definition of the AP indicates that it is capable of only two spatial streams

    • D. 

      Three spatial streams, because the definition of the AP indicates that it is capable of only three spatial streams.

  • 21. 
    You are implementing a VHT-capable AP. Which one of the following channels is available in the 802.11ac amendment to the 802.11-2012 standard, which was not available in the standard beforethis amendment?
    • A. 

      153

    • B. 

      144

    • C. 

      161

    • D. 

      56

    • E. 

      48

  • 22. 
    You are selecting antennas for a WLAN operating in the 5 GHz frequency band. Whatspecifications should be evaluated for an antenna before it is implemented in this WLAN system?(Choose 3)
    • A. 

      802.11ad compatibility

    • B. 

      TPC support

    • C. 

      Impedance in Ohms

    • D. 

      Elevation Beamwidth

    • E. 

      Return Loss Rating

    • F. 

      Operating Frequencies

  • 23. 
    What is the intended use for the WLAN hardware known as a pole or mast mount unit?
    • A. 

      Mounting a lightning arrestor to a grounding rod

    • B. 

      Mounting an omnidirectional antenna to a mast

    • C. 

      Mounting an RF amplifier to a dipole antenna

    • D. 

      Mounting a PoE injector to a perforated radome

    • E. 

      Mounting an access point to a site survey tripod

  • 24. 
    XYZ Corporation is experiencing connectivity problems with their existing building-to-building bridge link. A concrete wall on the roof of one building is partially blocking the Fresnel Zone, and the connection is dropping many frames. The administrator moves the antenna to an area not obstructed by the concrete wall and then realizes the RF cable cannot reach the new location If an extension cable is added to move the antenna, what are the likely results?
    • A. 

      The data throughput rate will increase because VSWR will decrease.

    • B. 

      The Equivalent Isotropically Radiated Power (EIRP) will decrease.

    • C. 

      The antenna’s azimuth beamwidth will decrease.

    • D. 

      The size of the Fresnel zone will increase.

    • E. 

      The likelihood of a direct lightning strike will increase.

  • 25. 
    When using an RF splitter to connect one transceiver to sector antennas loss is incurred. What isthis loss called?
    • A. 

      Conversion loss

    • B. 

      Through loss

    • C. 

      Active loss

    • D. 

      Intentional loss

  • 26. 
    What statements accurately describe the RF cables and connectors that are used in an 802.11WLAN system? (Choose 3)
    • A. 

      RF cables have upper and lower frequency range specifications.

    • B. 

      75 and 125 ohms are the typical impedances of 802.11 WLAN connectors.

    • C. 

      Two RF connectors of the same type (e.g. SMA), manufactured by different companies, may vary in specifications.

    • D. 

      Every RF connector causes insertion loss.

    • E. 

      Large diameter RF cables cause greater loss than small diameter cables.

  • 27. 
    What statement is true concerning the use of Orthogonal Frequency Division Multiplexing (OFDM)in IEEE 802.11 WLANs?
    • A. 

      802.11a and 11n use six (6) “pilot” subcarriers as a reference for the receiver to detect frequency and phase shifts of the signal.

    • B. 

      802.11a/g/n OFDM includes several combinations of modulation and coding to achieve data rates from 1-600 Mbps.

    • C. 

      With 802.11a OFDM, 16-QAM provides either 48 or 54 Mbps data rates, depending upon coding rates.

    • D. 

      802.11ac VHT-OFDM utilizes 256-QAM, which increases the data rate significantly over 64- QAM available in HT-OFDM.

    • E. 

      In 802.11a OFDM, fifty-six (56) subcarriers are used as parallel symbol transmission paths to carry data.

  • 28. 
    As a consultant, you’ve been hired by XYZ Company to provide recommendations about clientdevice selection, operation, and interoperability. What information should be considered to helpthem choose the right WLAN client devices?
    • A. 

      802.11n OFDM is more susceptible to high-power, narrowband interference than 802.11a

    • B. 

      In order to earn Wi-Fi Alliance certification, 802.11n clients stations are required to support both 2.4 and 5 GHz frequencies

    • C. 

      802.11ac devices support the features of the VHT PHY only in the 5 GHz frequency band.

    • D. 

      802.11ac is not backwardly compatible with 802.11n or 802.11a.

    • E. 

      When HR/DSSS devices are present, VHT MCS rates are disabled for the entire BSS.

  • 29. 
    Which IEEE 802.11 physical layer (PHY) specifications include support for and compatibility ofboth OFDM and HR/DSSS? (Choose 2)
    • A. 

      HR/DSSS (802.11b)

    • B. 

      OFDM (802.11a)

    • C. 

      ERP (802.11g)

    • D. 

      HT (802.11n)

    • E. 

      CCK (802.11b)

    • F. 

      VHT (802.11ac)

  • 30. 
    The IEEE 802.11-2012 standard requires VHT capable devices to be backward compatible withdevices using which other 802.11 physical layer specifications (PHYs)? (Choose 2)
    • A. 

      HT

    • B. 

      OFDM

    • C. 

      HR/DSSS

    • D. 

      ERP-PBCC

    • E. 

      DSSS-OFDM

  • 31. 
    • A. 

      Introduces “fast transition” roaming protocols for VoWiFi phones

    • B. 

      Better link reliability between 802.11a/b/g client devices and 802.11ac APs

    • C. 

      Improves service quality for real-time applications at greater distances

    • D. 

      Increases in receive sensitivity enhance RTLS location accuracy

    • E. 

      Stronger security with more robust encryption modes.

    • F. 

      Stronger security with more robust encryption modes.

  • 32. 
    What factors are likely to cause the greatest impact on the application layer throughput of an802.11n client station in a 2.4 GHz HT BSS? (Choose 3)
    • A. 

      Use of WEP or TKIP for encryption instead of CCMP

    • B. 

      Use of passphrase authentication instead of 802.1X/EAP authentication

    • C. 

      Increasing the beacon interval from 100 to 200 (TUs)

    • D. 

      RF interference from more than 10 nearby Bluetooth transmitters

    • E. 

      Increasing or decreasing the number of spatial streams in use by the client station and AP

  • 33. 
    What factors will have the most significant impact on the amount of wireless bandwidth availableto each station within a BSS? (Choose 2)
    • A. 

      The number of client stations associated to the BSS

    • B. 

      The power management settings in the access point’s beacons

    • C. 

      The presence of co-located (10m away) access points on non-overlapping channels

    • D. 

      The data rates at which nearby client stations are transmitting and receiving data

    • E. 

      The layer 3 protocol used by each station to transmit data over the wireless link

  • 34. 
    What are two channel modes specified by the 802.11n (High Throughput) PHY? (Choose 2) 
    • A. 

      20 MHz

    • B. 

      20/40 MHz

    • C. 

      40/80 MHz

    • D. 

      22 MHz

    • E. 

      80 MHz

    • F. 

      160 MHz

  • 35. 
    In an 802.11 2.4 GHz system, what 22 MHz channels are considered non-overlapping? (Choose2)
    • A. 

      Channels 5 and 10

    • B. 

      Channels 1 and 5

    • C. 

      Channels 3 and 7

    • D. 

      Channels 2 and 8

    • E. 

      Channels 8 and 11

    • F. 

      Channels 10 and 13

  • 36. 
    What facts are true regarding controllers and APs in a Split MAC architecture? (Choose 2)
    • A. 

      An IP tunnel is established between the AP and controller for AP management and control functions.

    • B. 

      Using centralized data forwarding, APs never tag Ethernet frames with VLAN identifiers or 802.1p CoS.

    • C. 

      With 802.1X/EAP security, the AP acts as the supplicant and the controller acts as the authenticator.

    • D. 

      Management and data frame types must be processed locally by the AP, while control frame types must be sent to the controller.

    • E. 

      In a distributed data forwarding model, the AP handles frame encryption and decryption.

  • 37. 
    The center frequency of channel 1 in the 2.4 GHz band is 2.412 GHz (2412 MHz).What is the center frequency of channel 4?
    • A. 

      2.413 GHz

    • B. 

      2.417 GHz

    • C. 

      2.422 GHz

    • D. 

      2.427 GHz

    • E. 

      2.437 GHz

  • 38. 
    What answers correctly complete the following sentence?____________ and ____________ carrier sense functions are used to determine if the wirelessmedium is busy. (Choose 2)
    • A. 

      Backoff

    • B. 

      Pseudo-random

    • C. 

      Virtual

    • D. 

      Active

    • E. 

      Physical

    • F. 

      Interframe

    • G. 

      Vector

  • 39. 
    In an 802.11n 2.4 GHz BSS, what prevents each station from using the full network bandwidth(e.g. 130 Mbps) for user data throughput when multiple clients are actively exchanging data withthe AP? (Choose 2)
    • A. 

      Radio receiver hardware cannot process data as quickly as it can be transmitted.

    • B. 

      Half of the bandwidth is allocated to uplink traffic and half to downlink traffic.

    • C. 

      The DCF and EDCA coordination functions require backoff algorithms

    • D. 

      WLAN devices cannot detect collisions and must receive positive frame acknowledgment.

    • E. 

      APs do not have sufficient wired connection speeds to the LAN.

  • 40. 
    When a client station sends a broadcast probe request frame with a wildcard SSID, how do APsrespond?
    • A. 

      After waiting a SIFS, all APs reply at the same time with a probe response.

    • B. 

      After waiting a SIFS, a designated AP sends an ACK, and then replies with a probe response.

    • C. 

      Each AP checks with the DHCP server to see if it can respond and then acts accordingly.

    • D. 

      For each probe request frame, only one AP may reply with a probe response.

    • E. 

      Each AP responds in turn after preparing a probe response and winning contention.

  • 41. 
    The IEEE 802.11a/n/ac physical layer technologies utilize the 5 GHz frequency band. What is trueof the channels in this frequency spectrum?
    • A. 

      14 channels are available worldwide

    • B. 

      11 channels are available worldwide.

    • C. 

      Regulatory domains worldwide require DFS and TPC in all these channels.

    • D. 

      DFS may be required in some regulatory domains on some channels.

    • E. 

      802.11 channels are separated by 5 Mhz

  • 42. 
    What features were introduced in the IEEE 802.11h amendment in order to uphold regulatoryrequirements for 5 GHz operation? (Choose 2)
    • A. 

      256-QAM

    • B. 

      Distributed Coordination Function (DCF)

    • C. 

      Phase Shift Keying (PSK)

    • D. 

      Transmit Power Control (TPC)

    • E. 

      Radio Resource Management (RRM)

    • F. 

      Dynamic Frequency Selection (DFS)

  • 43. 
    The OSI model is a 7-layer model for understanding the functions of a communication system.What OSI sublayers are specifically addressed by the IEEE 802.11-2012 standard? (Choose 2)
    • A. 

      Network

    • B. 

      PPDU

    • C. 

      PLCP

    • D. 

      MAC

    • E. 

      IP

    • F. 

      Transport

  • 44. 
    Which of the following frequency ranges are specified for use by IEEE 802.11 radios? (Choose all that apply.)
    • A. 

      902 - 928 MHz

    • B. 

      2.4000 – 2.4835 GHz

    • C. 

      5.15 – 5.25 GHz

    • D. 

      5.470 – 5.725 GHz

    • E. 

      5.725 – 5.875 GHz

  • 45. 
    Which data rate is supported by 802.11g radios that is not supported by 802.11a radios?
    • A. 

      9 Mbps

    • B. 

      11 Mbps

    • C. 

      12 Mbps

    • D. 

      54 Mbps

    • E. 

      65 Mbps

    • F. 

      130 Mbps

  • 46. 
    A Wi-Fi Alliance interoperability certificate indicates that a device is a/b/g/n certified. It furtherindicates one transmit and receive spatial stream for both the 2.4 GHz and 5.0 GHz bands. Itfurther indicates support for both WPA and WPA2 Enterprise and Personal. Finally, it indicatessupport for EAP-TLS, EAP-TTLS/MSCHAPv2, PEAPv0/EAP-MSCHAPv2 and PEAPv1/EAP-GTC.Which one of the following statements is false?
    • A. 

      This client device supports protection mechanisms such as RTS/CTS and/or CTS-to-Self.

    • B. 

      This client device supports both TKIP and CCMP cipher suites.

    • C. 

      300 Mbps is the maximum supported data rate for this device.

    • D. 

      This client device supports the ERP, OFDM, and HT physical layer specifications.

    • E. 

      This client device supports X.509 certificates for EAP authentication

  • 47. 
    When a client moves to a new BSS within an ESS, what steps are part of the 802.11 reassociationprocess? (Choose 2)
    • A. 

      The client station transmits a Reassociation Request frame to its current access point.

    • B. 

      The current access point informs the IP gateway of the reassociation.

    • C. 

      The current access point triggers the client’s reassociation service.

    • D. 

      The new access point transmits a Reassociation Response to the client station with a status value.

    • E. 

      The client and new access point create unicast encryption keys.

    • F. 

      The client station transmits a deauthentication frame to the current access point

  • 48. 
    In an enterprise WLAN, what condition will prevent a dual-band VHT/HT client device fromperforming a fast and seamless transition (i.e. latency-sensitive applications are not disrupted)between two access points that are managed by the same WLAN controller?
    • A. 

      The current AP is using channel 1 and the new AP is using channel 40.

    • B. 

      The SSID of the current AP does not match the SSID of the new AP.

    • C. 

      The current AP supports only HT and the new AP is VHT capable.

    • D. 

      The access points are hiding the SSID in Beacons and Probe Response frames

  • 49. 
    • A. 

      The SSID is a security session identifier used in RSNs.

    • B. 

      The SSID must be included in an association request frame.

    • C. 

      The SSID is an alphanumeric value assigned to device manufacturers by the IEEE.

    • D. 

      The SSID is a pseudo-random number assigned to each client by an AP.

    • E. 

      The SSID is an alphanumeric value with a maximum length of 32 octets.

    • F. 

      When configuring a new network, creating an SSID is optional.

  • 50. 
    What distinguishes an independent basic service set (IBSS) from an infrastructure basic serviceset (BSS)?
    • A. 

      An IBSS does not have a distribution system (DS), but a BSS does.

    • B. 

      An IBSS does not require beacon frames, but a BSS does.

    • C. 

      An IBSS does not support 802.11 authentication or association, but a BSS does.

    • D. 

      An IBSS does not support any 802.11ac enhancements, but a BSS does.

  • 51. 
    As XYZ Company’s wireless specialist, you have been asked to troubleshoot some unexpectedframe patterns in a wireless protocol capture. Your peers explain that the network’s beacon framesare inconsistent. That is, the BSSID is the same for all beacons, but the source address variesbetween three different addresses.What network configuration would cause this beacon frame behavior?
    • A. 

      A single AP supports multiple BSSs with different SSIDs

    • B. 

      A virtual cell single channel network has been implemented

    • C. 

      The beacons are from an IBSS instead of a BSS

    • D. 

      Three APs still share the same default configuration.

  • 52. 
    When compared with legacy Power Save mode, how does VHT TXOP power save improvebattery life for devices on a WLAN?
    • A. 

      VHT TXOP power save allows stations to enter sleep mode and legacy Power Save does not.

    • B. 

      VHT TXOP power save uses the partial AID in the preamble to allow clients to identify frames targeted for them.

    • C. 

      Legacy Power Save mode was removed in the 802.11ac amendment.

    • D. 

      VHT TXOP power save allows the WLAN transceiver to disable more components when in a low power state.

  • 53. 
    As defined in the 802.11 specification, legacy Power Save requires an inefficient back-and-forthframe exchange process. Due to this inefficiency, many WLAN device implementations use avariation of 802.11 Power Save to accomplish the same function.What non-standard power save behavior is used by most Wi-Fi devices in actual legacy PowerSave implementations?
    • A. 

      Client devices ignore the TIM field and automatically send PS-Poll frames after every beacon.

    • B. 

      After each beacon, the AP attempts to empty its frame buffer by sending Wake-on-WLAN frames to wake each dozing client.

    • C. 

      Request-to-Send and Clear-to-Send frame exchanges are used to trigger the delivery of buffered data.

    • D. 

      The Beacon interval is changed from the default 100 time units to 10 or less time units.

    • E. 

      Clients send null data frames to the AP and switch the power management bit from 1 to 0 to receive queued data.

    • F. 

      Stations send a CTS-to-self frame to the AP with a very long duration period so they can receive all of their buffered data at once.

  • 54. 
    What term correctly completes the following sentence?In an IEEE 802.11 frame, the IP packet is considered by the MAC layer to be a(n) _________.
    • A. 

      MAC Service Data Unit (MSDU)

    • B. 

      MAC Protocol Data Unit (MPDU)

    • C. 

      IP datagram

    • D. 

      PLCP Service Data Unit (PSDU)

    • E. 

      PLCP Protocol Data Unit (PPDU)

  • 55. 
    What term correctly completes the following sentence?802.11a/b/g used a mandatory 800ns guard interval. 802.11n introduced an optional short 400nsguard interval. Guard intervals (GI) are necessary in OFDM to reduce the likelihood of interferencebetween two consecutive ____________.
    • A. 

      Frames

    • B. 

      Packets

    • C. 

      Segments

    • D. 

      Bits

    • E. 

      Bytes

    • F. 

      Symbols

  • 56. 
    Prior to association, what parameter can 802.11 client devices measure and use to select theoptimal access point for association?
    • A. 

      Signal strength of access point beacons received

    • B. 

      Proximity to potential access points

    • C. 

      Retry rate of probe request and response frames

    • D. 

      Average round trip time to reach the Internet DNS server

    • E. 

      Average round trip time to reach the IP router

  • 57. 
    In an infrastructure Basic Service Set (BSS), how does the passive scanning process occur?
    • A. 

      Access points broadcast Beacons on all channels of each radio within the regulatory domain. Nearby client stations record information found in the Beacons for use in the association process.

    • B. 

      Client stations broadcast Probe Request frames on all supported channels in the regulatory domain. Nearby access points respond with Probe Response frames. Client stations record information in the Probe Response frames for use in the association process.

    • C. 

      Client stations broadcast Probe Request frames on the single channel for which they are programmed. Nearby access points respond on that channel with Probe Response frames. Client stations record information found in the Probe Response frames for use in the association process.

    • D. 

      Access points broadcast Beacons on a single channel for which they are programmed. Nearby client stations listen for Beacon frames and record information found in the Beacons for use in the association process.

  • 58. 
    During the discovery and connectivity process, client and AP stations exchange information abouttheir supported data rates. After the association, how do client and AP stations select thesupported data rate that will be used to send an 802.11 data frame?
    • A. 

      During the association, the client and AP agree to use the same transmit rate, but either station can request a change at any time after the association.

    • B. 

      The client and AP each choose the optimal data rate to use independently of one another, based on their own measurements related to the RF link.

    • C. 

      The client and AP may use different transmit rates, but the AP determines the data rate that will be used by each client station in the BSS.

    • D. 

      The client and AP may use different transmit rates, but the client determines the data rate that it will use and the data rate that the AP will use when communicating to the client.

    • E. 

      The client and AP may use a different transmit rates, but the transmit rate is determined by the peer station, based on the peer’s experience of the RF link.

  • 59. 
    As a station moves away from the access point to which it is associated, it changes its data ratefrom 600 Mbps to 540 Mbps and then to 450 Mbps.What IEEE 802.11 term is used to describe this functionality?
    • A. 

      Dynamic Rate Switching

    • B. 

      Multirate Control

    • C. 

      Modulation and Coding Selection

    • D. 

      Rate Set Selectivity

    • E. 

      Adaptive Rate Management

  • 60. 
    What statement about the IEEE 802.11e QoS facility is true?
    • A. 

      802.11 QoS is achieved by giving high priority queues a statistical advantage at winning contention.

    • B. 

      Four 802.1p user priorities are mapped to eight 802.11 transmit queues.

    • C. 

      When the Voice queue has frames awaiting transmission, no data will be transmitted from the Best Effort queue.

    • D. 

      To improve efficiency, Block Acknowledgments are required for Voice and Video WMM queues

    • E. 

      802.11 control frames are assigned to the 802.11 EF priority queue.

  • 61. 
    Which answer correctly completes the following sentence?The WMM certification, created by the Wi-Fi Alliance, is based on the ___________ coordinationfunction with support for ___________ QoS priority.
    • A. 

      Hybrid, contention-based

    • B. 

      Point, scheduled

    • C. 

      Dynamic, distributed

    • D. 

      Distributed, trigger-and-delivery

    • E. 

      Enhanced, contention-free

  • 62. 
    What component of the 802.11 standard allows stations to reserve access to the RF medium for aspecified period of time?
    • A. 

      Short guard intervals

    • B. 

      DTIM Interval

    • C. 

      Listen Interval

    • D. 

      Probe Request frames

    • E. 

      RTS or CTS frames

  • 63. 
    What statement about 802.11 WLAN performance is true?
    • A. 

      Use of larger frame sizes results in greater throughput in low interference environments

    • B. 

      BSS support for 65 KB A-MPDUs will increase the maximum data rate available to client devices.

    • C. 

      In 802.11ac, changing the security mechanism from WPA2-Personal to WPA2-Enterprise will enable the VHT MCS rates.

    • D. 

      Compared to an Independent BSS, an Infrastructure BSS can provide almost twice the throughput between wireless nodes.

    • E. 

      Use of short guard intervals improves reliability and throughput in high multipath environments

  • 64. 
    The 802.11 protocol specifies a fundamental channel access method that is required for allstations and is used in all IBSS and BSS networks.What is this fundamental channel access method called?
    • A. 

      DCF

    • B. 

      PCF

    • C. 

      HCF

    • D. 

      EDCAF

    • E. 

      HCCA

    • F. 

      PCF/CA

  • 65. 
    What mechanisms are specified by the IEEE 802.11 standard to attempt to prevent multiple radiosfrom transmitting on the RF medium at a given point in time? (Choose 3)
    • A. 

      Random backoff timer

    • B. 

      Clear channel assessment

    • C. 

      Network allocation vector

    • D. 

      Slot assessment value

    • E. 

      Collision detection

  • 66. 
    The client devices that connect to your network include a mix of dual-band 802.11n and 802.11ac,single-band 802.11b/g/n, and some 802.11a/g/n. Your access points are configured with the sameSSID on both the 2.4 and 5 GHz bands. The APs are also configured to prioritize clientconnectivity to 5 GHz.How does an AP perform band steering to encourage clients to use 5 GHz?
    • A. 

      When the client sends a probe request in the 2.4 GHz band, the AP may reply with information about the 5 GHz BSS.

    • B. 

      The AP may ignore the initial probe requests or 802.11 authentication requests sent in the 2.4 GHz band by dual-band clients

    • C. 

      The AP may allow an 802.11 association with the client in the 2.4 GHz band, then send unicast channel switch announcements to the client announcing the 5 GHz channel as the new channel.

    • D. 

      After receiving probe request frames from the same client in both bands, the AP may send an association request frame to the client in the 5 GHz band.

    • E. 

      The AP may allow an 802.11 association with the client in the 2.4 GHz band, then the AP may perform a transparent client handoff by transferring the client’s MAC address to the 5 GHz radio

  • 67. 
    What information is transmitted in the Beacon management frames of an HT access point tocommunicate about backward compatibility with ERP and HR/DSSS stations? (Choose 2)
    • A. 

      HT Protection mode

    • B. 

      Non-ERP Present field

    • C. 

      Secondary channel offset

    • D. 

      RIFS mode

    • E. 

      Power save mode of clients

  • 68. 
    What feature(s) are most likely to be supported by 802.11 enterprise-class WLAN controllers?(Choose 4)
    • A. 

      Link aggregation / port trunking

    • B. 

      802.1p and DSCP QoS

    • C. 

      BGP and Frame Relay

    • D. 

      Captive web portals

    • E. 

      IGMP snooping

  • 69. 
    ABC Company has thousands of Wi-Fi users accessing their network on a daily basis. TheirWLAN consists of 700 access points, 6 WLAN controllers, and a wireless network managementsystem.What network functions are performed by the enterprise-class WNMS? (Choose 3)
    • A. 

      RF pre-deployment planning and post-deployment reporting of access point locations on a floor plan

    • B. 

      Performance and security monitoring of WLAN controllers with alarms and notifications for

    • C. 

      Radio management, fast roaming, key caching, and other centralized control plane operations

    • D. 

      Centralized bridging of guest data traffic and application of firewall and QoS policies to data

    • E. 

      Management of WLAN controller configuration and provisioning of firmware updates

    • F. 

      Generating, encrypting, and decrypting 802.11 frames and collecting RF radio data.

  • 70. 
    In an 802.11n WLAN with a heterogeneous set of associated client devices including 802.11b,11g, and 11n, what HT protection mode will the BSS use?
    • A. 

      Mode 0: No protection mode (Greenfield)

    • B. 

      Mode 1: Nonmember protection mode

    • C. 

      Mode 2: 20 MHz protection mode

    • D. 

      Mode 3: Non-HT mixed mode