CWAP-404 実際試験問題と解答 - 模擬練習 - 受験自信を増やす

Question No : 1
What is the function of the PHY Preamble?

A.To set the modulation method for the MPDU
B.Allows the receiver to detect and synchronize with the signal
C.To terminate a conversation between transmitter and receiver
D.Carries the NDP used in Transmit Beamforming and MU-MIMO

正解:

Question No : 2
What is the function of the PMD sub-layer?

A.Converts 1s and 0s given to it by the PLCP sub-layer into the appropriate RF signals
B.Provides framing
C.Adds a PHY preamble and header to a PSDU
D.Performs A-MPDU

正解:

Question No : 3
Finish the statement. It is possible to distinguish between _______and ______20 MHz transmissions when looking at an FFT plot.

A.HR/DSSS and ERP
B.ERP and VHT
C.HT and VHT
D.OFDM and HT

正解:

Question No : 4
A manufacturing facility has installed a new automation system which incorporates an 802.11 wireless network. The automation system is controlled from tablet computers connected via the WLAN.
However, the automation system has not gone live due to problem with the tablets connecting to the WLAN. The WLAN vendor has been onsite to perform a survey and confirmed good primary and secondary coverage across the facility. As a CWAP you are called in to perform Spectrum Analysis to identify any interference sources. From the spectrum analysis, you did not identify any interference sources but were able to correctly identify the issue.
Which of the following issues did you identify from the spectrum analysis?

A.The tablets are entering power save mode and failing to wake up to receive the access points transmissions
B.A high noise floor has resulted in a SNR of less than 20%
C.The tablets are connecting to the wrong SSID
D.There is a power mismatch between the APs and the clients

正解:

Question No : 5
Which common feature of a Spectrum Analyzer would be the best to help you locate a non-802.11
interference source?

A.Max hold
B.Location filter
C.Waterfall plot
D.Device finder

正解:

Question No : 6
You have installed a new 802.11ac WLAN configured with 80 MHz channels. Users in one area are
complaining about poor performance. This area is currently served by a single AP. You take a spectrum
analysis capture in the poor performing areA. While examining the waterfall plot you notice the airtime
utilization is higher on the first 20 MHz of the 80 MHz channel when compared to the rest of the channel.
What do you conclude?
A. The AP is misconfigured and needs to be reconfigured to 80MHz operation
B. RRM is enabled and has dynamically picked a 20 MHz channel
C. The first 20 MHz is the AP’s primary channel and higher airtime utilization on the primary channel is normal when an AP Is configured for 80 MHz operation
D. Non Wi-Fi interference is preventing the APs 80 MHz operation

正解: C

Question No : 7
In a Spectrum Analyzer the Swept Spectrogram plot displays what information?

A.The RF time domain
B.RF power present at a particular frequency over the course of time
C.Wi-Fi Device information
D.Duty cycle in the frequency domain

正解:

Question No : 8
ABC International has installed a new smart ZigBee controlled lighting system.
However, the network team is concerned that this new system will interface with the existing WLAN and has asked you to investigate the impact of the two systems operating simultaneously in the 2.4 GHz band. When performing Spectrum Analysis, which question could you answer by looking at the FFT plot?

A.Do the ZigBee channels used by the lightning system overlap with the WLAN channels?
B.Is the ZigBee system using more the 50% of the available airtime?
C.Is the ZigBee system causing an increase in WLAN retries?
D.Is the WLAN corrupting ZigBee system messages?

正解:

Question No : 9
You’re the WLAN administrator for a large retailer based at the HQ in New York. The London-based office has been complaining about WLAN disconnections around lunch time each day. You suspect this might be interference from the staff microwave, how might you test your theory from the New York office?

A.Access the microwave remotely and run a diagnostic check
B.Ask a local member of staff to take some pictures of the microwave, including some close-ups of the door seal so that you can access it
C.Place one of the London APs into spectrum analyzer mode and monitor the situation over lunch time
D.Ask a local member of staff to change the frequency of the microwave and see if the disconnections stop

正解:

Question No : 10
Which one of the following is required for Wi-Fi integration in laptop-based Spectrum Analyzer software?

A.A supported WLAN adaptor with a customized driver
B.Any 802.11 wireless adaptor
C.A dual radio spectrum analyzer card
D.SNMP read credentials to the WLAN controller or APs

正解:

Question No : 11
802.11k Neighbor Requests and Neighbor Reports are sent in what type of Management Frames?

A.RRM
B.Action
C.Beacon
D.Reassociation Request and Reassociation Response

正解:

Question No : 12
The network administrator at ABC Engineering has taken a large packet capture from one of their APs running in monitor mode. She has very little knowledge of 802.11 protocols but would like to use the capture file to evaluate the overall health and performance of their wireless network. When she asks your advice, which tool do you recommend she opens the packet capture file with?

A.Capture visualization tool
B.Protocol analyzer
C.Spectrum analyzer
D.WLAN scanner

正解:

Question No : 13
Which one of the these is the most important in the WLAN troubleshooting methodology among those listed?

A.Interview the network manager about the issues being experienced
B.Talk to the end users about their experiences
C.Observe the problem
D.Obtain detailed knowledge of the wireless vendors debug and logging options

正解:

Question No : 14
Protocol analyzers may present field values in either binary, decimal or hexadecimal.
What precedes a
hexadecimal value to indicate it is hexadecimal?

A.0x
B.%
C.HEX
D.16x

正解:

Question No : 15
You are performing a multiple adapter channel aggregation capture to troubleshoot a VoIP roaming problem and would like to measure the roaming time from the last VoIP packet sent on the old AP’s channel to the first VoIP packet sent on the new AP’s channel.
Which timing column in the packet view would measure this for you?

A.Delta
B.Absolute
C.Roaming
D.Relative

正解:

CWAP CWAP-404 問題練習