XYZ Corporation is renting space in a multi-tenant office building and has recently installed a new 802.11b wireless LAN in their office. The network administrator has very little experience with wireless LANs, and has recently purchased a wireless LAN protocol analyzer for diagnostic use. He has attended a wireless administration class and understands basic wireless LAN operation. During the course of troubleshooting a performance problem, the administrator cannot understand why he is seeing ATIM frames, CF-End frames, and PS-Poll frames on channel 2 all at the same time. You are hired by the administrator as a consultant to explain why this is happening. Which of the following explanations is NOT plausible?

• A. Seeing ATIM frames, CF-End frames, and PS-Poll frames in the same capture is normal. Seeing these frames together means that Power Save Poll mode is in use on a PCF mode network.
• B. XYZ Corp's wireless LAN is using channels 1, 2, and 3. This design is causing adjacent channel interference, which is corrupting 802.11b frames. The analyzer is seeing this frame corruption and reporting the frames as it sees them.
• C. XYZ Corp's wireless LAN is using channels 1, 6, and 11. The frames the administrator is seeing while capturing on channel 2 are corrupted frame fragments that the analyzer is attempting to interpret.
• D. XYZ Corp's wireless LAN is using channel 2, and their neighbors in the building are running PCF mode networks and Ad Hoc networks on channel 2 as well. Each of the wireless networks have client stations operating in low-power mode.

Which of these functions specifically relate to 802.11b/g mixed mode operation when both
802.11b and 802.11g client stations are active on the network?

• A. CF-End frames
• B. Null Function Data frames
• C. CTS-to-Self frames
• D. Fragmentation Thresholds
• E. PS-Polling frames

Errors at the PLCP layer are common in wireless LANs. Which of the following is NOT a common PLCP error type?

• A. PLCP Format Errors
• B. PLCP Overrun Errors
• C. PLCP CRC Errors
• D. PLCP Length Errors

ABC Company has hired you to troubleshoot an intermittent performance problem with their 802.11g wireless LAN. They have noticed that intermittently throughout a typical day, their wireless LAN latency increases enough to interrupt some mission critical applications.
ABC demands that you wait until after business hours to begin any troubleshooting that might cause service interruptions to the wireless network. Considering that ABC Company has no baseline analysis, what possible first step do you take toward troubleshooting ABC Company wireless network problem?

• A. After business hours, you search for wireless clients that are transmitting too many Probe Request frames and temporarily replace them as a troubleshooting measure.
• B. After business hours, you enable the traffic generator function of a wireless protocol analyzer in order to simulate various high utilization conditions on the network while testing ABC Company applications.
• C. You install protocol analyzer probes near each access point in order to see if a large percentage of data frames are carrying their maximum payload over the next two days.
• D. Using a protocol analyzer, you search for rogue access points that might be causing interference in the 2.4 GHz ISM band by emitting beacons.
• E. You perform a walk-through of ABC Company premises during business hours using a protocol analyzer looking for data frames with high Retry counts and MAC CRC Error counts.
• F. You perform a walk-through of ABC Company's premises during business hours using a protocol analyzer looking for 802.11g Basic Service Sets that have both 802.11b and
  802.11g stations associated. You then compare this information to where the latency is being experienced.