CWNP CWDP Certifications PW0-250 Questions & Answers

• Question 51:

  Given: The 802.11n APs you have selected for your public access deployment support many of the PHY and MAC enhancements offered by the 802.11n standard. The AP is single-band (2.4 GHz) and only allows 20 MHz channels. The WLAN radio in the AP is a 3x3 802.11n chip that supports two spatial streams.

  What is the maximum MCS rate that could be supported by this AP?

  A. 54 Mbps

  B. 65 Mbps

  C. 108 Mbps

  D. 144 Mbps

  E. 150 Mbps

  F. 300 Mbps

  Correct Answer: D

• Question 52:

  As an implementation engineer, you have just received initial design specs from a network designer for your dual-band 802.11n deployment. The network design documents prescribe the following data rate configuration for the 2.4 GHz radio:

  Basic Rates -- 5.5, 6, 11, 12 Mbps

  Supported Rates --9, 18, 24, 36, 48, and 54 Mbps as well as MCS 0-15

  What will result from this design strategy?

  A. By disabling support for 1 and 2 Mbps while allowing 5.5 and 11 Mbps, the network will force 802.11b clients to use these higher data rates.

  B. Protection mechanisms will always be in use on this network to support 5.5 and 11 Mbps as basic rates.

  C. HR/DSSS (802.11b) stations will not be able to associate to the service set.

  D. This configuration violates the IEEE specification that defines 6, 12, and 24 Mbps as mandatory data rates for 802.11g/n.

  E. MCS 0 will represent the lowest data rate that can be used in the service set.

  Correct Answer: C

• Question 53:

  Given: As the wireless network administrator for XYZ Company, you are planning to upgrade your aging wireless network infrastructure, as well as some clients, to support 802.11n. In your research, you have discovered that your new wireless client devices and infrastructure are 802.11n, WMM, and WMM-PS certified by the Wi-Fi Alliance. Some of your existing client devices are 802.11a/b/g devices that do not support WMM.

  Given this information, what scenario is possible when your company's employees begin using both types of client devices on the new WLAN?

  A. All WMM-PS certified client devices will be prevented from utilizing WMM-PS features until all stations in use on the wireless medium are WMM-PS certified.

  B. The WLAN infrastructure will set the dozing times of the WMM-PS certified client devices based upon their WMM access category, while the non-WMM-PS client devices will continue to use PS- Poll frames.

  C. Performance and battery life will be inconsistent between WMM-PS and non-WMM-PS client devices when used with applications that support WMM-PS.

  D. WMM-PS enabled APs will allow both WMM-PS and non-WMM-PS stations to use the trigger- and-delivery mechanism, but WMM-PS stations will get priority.

  E. When all STAs are using Power Save features, WMM-PS STAs will experience poor performance due to PS protection mechanisms.

  Correct Answer: C

• Question 54:

  To achieve a 450 Mbps MCS, what 802.11n features (from the numbered list below) are required?

  1.

  Frame aggregation

  2.

  Short GI

  3.

  40 MHz channels

  4.

  2 spatial streams

  5.

  3 spatial streams

  6.

  Transmit beamforming (TxBF)

  A. 1, 2, 3, 4

  B. 1, 2, 3, 5

  C. 1, 2, 3, 4, 6

  D. 1, 2, 3, 5, 6

  E. 2, 3, 4

  F. 2, 3, 5

  Correct Answer: F

• Question 55:

  Given: Use Exhibit 1, 2, and 3 to answer the question.

  

  

  The azimuth and elevation charts for which type of antenna are shown in Exhibit 1?

  A. Figure 1

  B. Figure 2

  C. Figure 3

  D. Figure 4

  E. Figure 5

  F. Figure 6

  Correct Answer: C

• Question 56:

  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.

  Correct Answer: C

• Question 57:

  When a WLAN controller transmits an Ethernet frame that has an IEEE 802.11 frame as its payload to a lightweight AP, what type of QoS marks can be applied to the Ethernet frame and/or its payload? (Choose 3)

  A. IEEE 802.1Q PCP marks in the Ethernet frame header

  B. User Priority marks in the IEEE 802.11 frame header

  C. Throughput subscription marks in the Ethernet frame header

  D. MPLS tags from the Label Edge Router (LER)

  E. DSCP marks to the ToS bits in the encapsulating IP packet header

  F. RSVP tag if RTP is the payload of the IEEE 802.11 frame

  Correct Answer: ABE

• Question 58:

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

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

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

  Correct Answer: AB

• Question 59:

  Your customer location is equipped with DAS, originally deployed to relay a GSM signal indoors and provide 802.11 data coverage to static stations. What type of wireless application would be least likely to be supported by this RF distribution model?

  A. On-demand video streaming over wireless

  B. Data connection with frequent roaming

  C. Location-based services for wireless assets or RFID tags

  D. VoWLAN if the codec is G.729.

  E. FTP over implicit TLS/SSL

  Correct Answer: C

• Question 60:

  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

  Correct Answer: AB