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CWNA Wlan Troubleshooting

Subjects : cisco, it-skills, cwna
Instructions:
  • Answer 28 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Occurs when one client station's transmissions are unheard by other client stations in the BSS. Every time the hidden node transmits - there is a risk another stations is also transmitting and a collision can occur.






2. Unnecessary medium contention overhead that occurs when AP with overlapping coverage cells are configured to transmit on the same frequency channel. Because of the CSMA/CA - all nearby AP's and clients on the same channel will defer transmissions. Th






3. Determining how big the cell size needs to be to provide the desired coverage - and adjusting the power level of the AP in order to create a cell of the desired size. Cell-sizing is almost always the preferable method for meeting capacity needs in an






4. Proper network design entails providing the necessary coverage while trying to limit the number of devices connected to any single AP at the same time. This design process ensures the highest level of throughput to the individual stations by limiting






5. In order to avoid co-channel interference - a channel reuse pattern is necessary. Overlapping RF coverage cells are needed for roaming - but overlap frequencies must be avoided. The only 3 channels that meet these criteria in the 2.4 GHz ISM band are






6. An error-detecting code






7. Defines faster handoffs when roaming occurs between cells in a wireless LAN using the strong security defined in a robust security network. Fast and secure 802.11 roaming is needed to meet latency requirements for time-senstive applications in a WLAN






8. Data corruption cause by the delay spread in a multipath environment. The difference in time between the primary signal and the reflected signals causes problems for the receiver when demodulating the RF signals information. The delay spread time dif






9. All-band interference is RF interference that occurs across the entire frequency range that is being used. The term all-band interference is typically associated with FHSS communications that disrupt HR-DSS and/or ERP-OFDM channel communications.






10. Mechanisms on a WLAN controller that prioritizes transmissions from stations with higher data rates over stations using lower data rates






11. BSSID is typically the MAC address of the AP's radio card and the layer 2 identifier of a BSS. Because AP's are capable of advertising multiple SSIDs - and because each SSID requires a separate BSSID - the AP will generate virtual BSSID addresses






12. A low-powered client station that is a great distance from the AP could become an unheard client if other high-powered stations are very close to the access point. The transmissions of high-powered stations can raise the noise floor to a higher level






13. The delay between the reception of the main signal and the reflected signal






14. The SNR is the difference in decibels between a received signal and the background noise. The SNR is an important value because - if the background noise is too close to the received signal - data can get corrupted and retransmissions will increase.






15. Degradation of performance caused by Layer 2 retransmissions resulting from overlapping frequency space that occurs because of an improper channel reuse design.






16. Placing multiple AP's in the same physical space to provide for greater capacity. In a multiple channel architecture (MCA) three AP's operating in the 2.4 GHz ISM band could be colocated in the same physical area.






17. A wireless network design in which AP's are configured with the power set to the maximum level to provide the largest coverage area possible. Coverage also defines the physical area where a usable signal can be received by the station






18. A WLAN architecture in which all AP in the network can be deployed on one channel in either the 2.4 GHz or 5 GHz frequency bands. Uplink and downlink transmissions are coordinated by a WLAN controller on a signal 802.11 channel in such a manner that






19. Any roaming technology that allows mobile-device users to move from one layer 3 network to another while maintaining their original IP address






20. A mechanism in which client station resources data is gathered and processed by an AP or WLAN controller.






21. The ability for the client stations to transition from one AP and BSS to another while maintaining network connectivity for upper-layer applications.






22. The concept that antennas amplify received signals just as they amplify transmitted signals






23. In a single channel architecture - each layer of multiple APs on a single channel and using the same virtual BSSID is known as a channel blanket






24. Also known as dynamic rate shifting - adaptive rate selection - or automatic rate selection. A process that client stations use to shift to lower-bandwidth capabilities as they move away from an AP and to higher-bandwidth capabilities as they move to






25. Any RF communications system that has multiple antennas at both ends of the communication link and being used concurrently.






26. The area or distance that an RF signal can provide effective usable coverage.






27. A WLAN channel reuse pattern with overlapping coverage cells that utilize three channels at 2.4GHz or numerous channels at 5 GHz.






28. A propagation phenomenon that results in two or more paths of a signal arriving at a receiving antenna at the same time or within nanoseconds of each other.