PW0-250 Online Practice Questions and Answers

In a manufacturing facility with highly reflective materials, you are planning an upgrade to your existing 802.11b solution. You have chosen a dual-band 802.11n infrastructure product for this purpose. Your client applications include:

Handheld scanners -- for inventory management

Toughbooks (laptops) -- mounted on forklifts for inventory and workflow management

VoWiFi phones -- used by select employees throughout the facility

You are evaluating all of the 802.11n enhancements and determining which features to enable for your environment and applications.

In this scenario, what 802.11n enhancements should NOT be enabled on the 2.4 GHz radio of the new APs? (Choose 2)

A. 40 MHz channels

B. Short guard intervals

C. Block Acknowledgments

D. Frame aggregation

E. MRC

F. STBC

Multicast video applications typically require special treatment on the Wi-Fi network due to the nature of multicast traffic. Many vendors implement proprietary multicast-to-unicast conversion for this reason.

Which of the following is NOT a valid reason for special unicast conversion of downlink multicast traffic?

A. In QoS WLANs, multicast traffic is always assigned to the best effort (AC_BE) transmit queue.

B. Group addressed downlink frames are not acknowledged on the wireless medium.

C. Multicast traffic must always be transmitted via omnidirectional antennas.

D. Frames with a group receiver address must always be sent at a rate in the Basic Rate Set.

An associated STA detects a new BSS with the same SSID as the STA's current BSS. The new BSS uses a different IP subnet than the current BSS. If the STA is configured to use 802.1X/EAP preauthentication, what is likely to occur?

A. The STA will not attempt to preauthenticate because the new BSS uses a different IP subnet.

B. The STA will attempt to preauthenticate, but fail because the new BSS uses a different data-link broadcast domain.

C. The STA will attempt to preauthenticate and succeed if DHCP is supported on the new subnet.

D. The STA will attempt to preauthenticate and succeed if IP Mobility is enabled on the AP or WLAN controller.

E. The STA will attempt to preauthenticate and succeed if the current AP has shared its cached PMK.

You deployed an AP and installed its antenna, and you now need to set the AP transmit power. Given a desired EIRP of 21 dBm, and an antenna gain of 5.85 dBd connected through 25 feet of cable with a loss specification of 4 dB/100 feet. Assuming that there is no significant loss from the connectors, what should be the transmit power level for this AP?

A. 10 mW

B. 14 mW

C. 20 mW

D. 25 mW

E. 40 mW

F. 50 mW

You told your customer that multipath fading may be mitigated simply by moving one or both of the receiver's antennas a little bit, usually by one to four wavelengths away from its original position. Your customer is prepared to make the change, but does not know the wavelength for 802.11a.

What is the approximate wavelength of an 802.11a radio wave?

A. 5.5 cm (2.16 inches)

B. 12 cm (4.72 inches)

C. 15.24 cm (6 inches)

D. 45 cm (17.71 inches)

E. 58 cm (22.83 inches)

What exhibit reflects the recommended life-cycle steps for successfully designing and deploying an enterprise WLAN from start to finish? (Choose 2)

A. Solution 1

B. Solution 2

C. Solution 3

D. Solution 4

E. Solution 5

In a PC-based spectrum analyzer, what data chart identifies the overall RF utilization of a specific frequency in the environment being surveyed?

A. FFT Max Hold

B. FFT Average

C. Swept Spectrogram

D. Duty cycle

E. Sweep Time

F. Bandwidth resolution

You captured the wireless frame shown in the exhibit during a post-deployment verification site survey.

What can you tell the customer about this network?

A. This is a video stream packet, and there is a QoS marking issue on the wired side, because the DSCP value should not be set to 0.

B. This is a voice control packet, and the configuration looks normal, as voice control may or may not have a DSCP tag.

C. This is a video stream packet, and the configuration looks normal, as DSCP is always set to 0 when 802.11e QoS is specified at Layer 2.

D. This is a voice RTP packet, and its marking was downgraded from Voice to Video which is a sign of congestion issues.

During a post-deployment verification, you are requested to troubleshoot an area where users are experiencing poor throughput. They are using data communication only, mainly from laptops. You captured the frame displayed in the exhibit from the location where problems are reported. This frame is typical of those that were captured by the analyzer.

What does this frame reveal about the RF network in this area?

A. One station seems to be streaming video, thus may have reserved significant bandwidth via admission control

B. Contention Free is in place in this network, which may starve some non-QoS stations from access

C. Multipath or excessive collisions seem to be an issue in this area

D. The AP seems to be too far to provide enough coverage to this area

E. Stations are using null data frames as protection mechanisms to reserve the medium

F. The station that sent this frame is causing a DoS attack by using extended Duration values

As you plan a WLAN upgrade, you have assessed the network requirements and data signatures of your applications. One of the popular applications used on your network requires high bandwidth and low to medium Wi-Fi loss, but can tolerate moderate latency and jitter.

What application matches this description?

A. FTP

B. Email

C. Skype chat

D. Voice

E. Video conferencing

F. Video-on-demand