Q1. An engineer is deploying an outdoor Mesh network. Which four major factors should be considered? (Choose four.)
A. power
B. buildings
C. traffic lights
D. satellite dishes
E. line of sight
F. network connectivity
G. power lines
H. mounting
Answer: A,E,F,H
Q2. A hospital environment was designed to guarantee RF coverage at or better than -67 dBm in the 5 GHz spectrum. The customer mandates that RRM be used for DCA and TPC in both bands. After deployment, why do many of the legacy 802.11b/g devices have difficulty maintaining connectivity?
A. Excessive co-channel interference in the 2.4 GHz band exists.
B. Excessive overlapping channels in the 2.4 GHz band exists.
C. TPC drastically reduces Tx power in the 2.4 GHz band.
D. TCP drastically increases Tx power in the 2.4 GHz band.
Answer: C
Q3. An engineer is planning for a 24 Mbps data rate for a new installation. What is the coverage area from the AP if the environment and other factors are not taken into consideration?
A. 225 feet
B. 80 feet
C. 150 feet
D. 100 feet
Answer: A
Q4. An engineer is tuning RRM parameters to improve client connectivity. Which channel band results in the best 802.11n client compatibility?
A. UNII-2
B. UNII-2e
C. UNII-3
D. UNII
E. UNII-1
Answer: E
Explanation:
802.11n operates on the same channel as 802.11a. For better compatibility with 802.11n clients, it is recommended to stay on lower channels (UNII-1 band).
Reference: http://www.cisco.com/c/en/us/support/docs/wireless/4400-series-wireless-lan-controllers/108184config-802-11n-wlc.html
Q5. When designing a WLAN, AP placement is important. Which option describes how to rank the density of APs needed to support location services versus data and voice services?
A. Data services have the lowest density of APs compared to location services, which has the highest density.
B. Data services have a lower density of APs compared to location services, but more than voice.
C. Voice services have the highest density of APs over location and data services.
D. Voice and data services require a higher density of APs than location services.
Answer: A
Q6. Which two best practices should be considered when a customer wants to purchase and implement Voice over Wireless for Cisco 7925 IP Phones? (Choose two.)
A. Enable lower data rates for 2.4-GHz data WLAN and higher data rates for phones.
B. Use a separate Cisco Wireless Lan Controller.
C. Enable 802.1x and Cisco Centralized Key Management for phone authentication.
D. Use dedicated Access Points only for Voice over Wireless.
E. Set data for 2.4 GHz and voice for 5 GHz using separate SSIDs.
Answer: C,E
Q7. When reviewing a design for a voice over wireless deployment, what per-call bandwidth cost should be factored in when determining maximum calls per cell using SIP and G.711u as the codec?
A. 64 bytes
B. 8 bytes
C. 80 bytes
D. 10 bytes
Answer: C
Q8. As part of a wireless site survey in a hospital, an engineer needs to identify potential Layer 1 interferers. In which three areas is the engineer most likely expect to find sources of 2.4 GHz and 5 GHz RF noise? (Choose three.)
A. emergency room
B. magnetic resonance imaging
C. laboratory
D. X-ray radiography
E. Gamma Knife radiation treatment
F. kitchen
Answer: A,C,F
Q9. An 802.11n implementation is being discussed. Users are satisfied with the potential 300- 450 Mbps throughput of new 802.11n APs. Which three bandwidth requirements are used to calculate per client bandwidth through an 802.11n AP network? (Choose three.)
A. 450 Mbps throughput is the client max for 5-GHz radio.
B. Channel bonding on 5 GHz is required for a client to have a 300 Mbps WiFi link.
C. 300 Mbps throughput is the client max for 2.4-GHz radio.
D. The remaining bandwidth is divided per device when more clients are connected to one AP.
E. 100 Mbps Ethernet switch port is a potential bottleneck.
F. CleanAir helps clear noise for 802.11n channel bonding to work.
Answer: A,C,D
Q10. Which three options are benefits of U-APSD? (Choose three.)
A. optimized power-save mode periods
B. increased call capacity
C. bandwidth reservation
D. synchronization of the transmission and reception of voice frames
E. efficient roaming
F. priority bandwidth and polling
Answer: A,B,D
Explanation:
Unscheduled automatic power-save delivery (U-APSD) is a feature that has two key benefits:
The primary benefit of U-APSD is that it allows the voice client to synchronize the transmission and reception of voice frames with the AP, thereby allowing the client to go into power-save mode between the transmission/reception of each voice frame tuple. The WLAN client frame transmission in the access categories supporting U-APSD triggers the AP to send any data frames queued for that WLAN client in that AC. A U-APSD client remains listening to the AP until it receives a frame from the AP with an end-of-service period (EOSP) bit set. This tells the client that it can now go back into its power-save mode. This triggering mechanism is considered a more efficient use of client power than the regular listening for beacons method, at a period controlled by the delivery traffic indication map (DTIM) interval, because the latency and jitter requirements of voice are such that a WVoIP client would either not be in power-save mode during a call, resulting in reduced talk times, or would use a short DTIM interval, resulting in reduced standby times. The use of U-APSD allows the use of long DTIM intervals to maximize standby time without sacrificing call quality. The U-APSD feature can be applied individually across access categories, allowing U-APSD can be applied to the voice ACs in the AP, but the other ACs still use the standard power save feature.
The secondary benefit of this feature is increased call capacity. The coupling of transmission buffered data frames from the AP with the triggering data frame from the WLAN client allows the frames from the AP to be sent without the accompanying interframe spacing and random backoff, thereby reducing the contention experience by call.
Reference:
http://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Mobility/vowlan/41dg/vowlan41dg-book/vowlan_ch2.html#wp1045982