PW0-250 Online Practice Questions and Answers

In a multiple channel architecture (MCA) network supporting 802.1X authentication, what aspects of WLAN design affect client roaming efficiency and effectiveness? (Choose 3)

A. Channels supported by infrastructure

B. Key caching protocols

C. Cipher suite

D. PHY standard used by client

E. Supported uplink and downlink MCS rates

F. The infrastructure's roaming algorithm

G. Channels supported and scanned by client

What is the purpose of DHCP Option 43, and how is it used with WLANs?

A. It provides clients with a temporary IP address on a restricted VLAN until 802.1X authentication is completed. Then the client receives its long-term IP address.

B. It provides IP address bindings for specific network nodes that require long-term IP address assignments. WLAN controllers are configured to use Option 43 to receive long-term IP address leases that are centrally managed with DHCP.

C. It supports vendor-specific IP address attributes for node discovery purposes. APs use Option 43 with vendor class identifiers to obtain the IP address of a centralized WLAN controller.

D. It integrates a DHCP server with AAA servers and user databases to dynamically assign IP addresses to client devices. During 802.1X, the AAA server uses Option 43 to notify the DHCP server what IP pool the client's address should be drawn from.

When preparing a floor plan graphic for use in predictive and manual site surveying, what calibration method will lead to the most accurate and reliable RF data?

A. Use the known size of a small object, such as a ceiling tile, and use a single instance of this object (e.g. a single ceiling tile) to scale the floor plan.

B. Measure the width of an actual office doorway with a tape measure and use this value to calibrate against a doorway graphic.

C. Use the longest available measurement (like a straight exterior wall) to calibrate the graphic's scale.

D. Calibrate the ceiling height of the floor plan first, then the survey software should be able to auto-calibrate the X and Y planes of the graphic.

E. With properly formatted .bmp and .png graphics, the site survey software should be able to extract the scale directly from the graphic data during import.

A wireless engineer from your company performed a site survey in an office building where a wireless network extension was needed. He reports that while performing a Layer 1 sweep near a meeting room full of people, he detected the RF environment displayed in the exhibit. He is unsure how to interpret what he recorded to determine its impact on a future Wi-Fi network.

A. The signal affects the entire spectrum and will render the wireless network unusable. It must be located and removed.

B. The signal has a low duty cycle and should not be of major impact on the wireless network.

C. The signal is alternating between peaks (high interference level) and valleys (low interference level). The network channel design must be built to avoid the affected peak frequencies.

D. The signal is typical of a high radio card background noise. It shows that the card used for the Layer 1 sweep should be replaced and the Layer 1 sweep re-done.

E. The Real Time FFT shows a high amplitude, narrowband jammer pulsing across the entire 2.4 GHz band. This will cause significant, intermittent interference to the WLAN.

A Layer 1 sweep was performed at a customer location, and you are asked to review a capture taken during the survey.

What is the meaning of the chart shown in the exhibit and how should it be interpreted?

A. Real Time FFT means Real Time First Fundamental Trace and shows the value of the first signal detected on each frequency at each sweep interval.

B. Real Time FFT means Real Time Fast Frequency Timing and shows the RF pulses measured by the Layer 1 sweep tool.

C. Real Time FFT means Real Time Fast Fourier Transform and shows the max value of the signal detected on each frequency in real time.

D. Real Time FFT means Real Time Frequency Fundamental Texture and shows the value of the noise background generated by the card used to perform the Layer 1 sweep.

Given: In a site survey deliverable report, you are expected to explain the spectrum measurements taken at the customer's site. The exhibit shows a representative sample capture of the RF environment at one of the customer sites.

What best explains the data presented in this exhibit?

A. The Real Time FFT chart shows a high noise floor across the entire 2.4 GHz band.

B. Channel 1 is being heavily utilized by Wi-Fi and channel 11 also has some moderate Wi-Fi activity.

C. As indicated by the data in the Active Devices list, the spectrum analysis chipset is also reporting 802.11 information.

D. Although some access points are present in a nearby area, they are not being heavily used.

You are testing a VoWLAN deployment, and your communication measurements show a certain amount of lost packets. What would be an acceptable packet error rate value to still provide acceptable call quality?

A. There should be 0% error in a VoWLAN type of deployment

B. No more than 1% PER max should be acceptable

C. No more than 4% PER max should be acceptable

D. No more than 8% PER max should be acceptable

E. No more than 12% PER max should be acceptable

When deploying long-distance 802.11 bridge links (10 miles / 16 km), what parameter may be critical for improving data flow by reducing retries caused by the long distances?

A. The sequence control field value

B. The PHY parameter set field

C. The minimum transmit data rate value

D. The CTS-to-self threshold

E. The Beacon interval

F. The acknowledgement timeout threshold

In a centralized WLAN architecture, what new problem may arise when you change the data forwarding model from centralized to distributed? (Choose 2)

A. APs that were designed for a centralized forwarding model may not support all features in distributed forwarding mode.

B. Centralized control functions, such as key management and distribution, RRM, and load balancing will no longer be supported.

C. All RRM controls will also need to be distributed to a master AP that acts as a channel and transmit power arbiter for other APs in the ESS.

D. The Ethernet switch ports to which APs are connected may need to be reconfigured to support VLAN tagging and QoS at the network edge.

E. APs will not have the processing capabilities to support AES-CCMP, so TKIP will be the recommended encryption method.

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