CWNP Updated CWDP-305 Exam Questions and Answers by macsen

In Wi-Fi networks, the 802.11e amendment introduces Quality of Service (QoS) by defining Access Categories (ACs) to prioritize different types of traffic.The AC_VO (Voice) category is designated for voice traffic, which requires low latency and jitter.To maintain QoS across both wireless and wired networks, it's essential to map these categories to appropriate Differentiated Services Code Point (DSCP) values.

The AC_VO category corresponds to the Expedited Forwarding (EF) DSCP value, which is 46.This mapping ensures that voice traffic receives high priority treatment throughout the network, minimizing delays and ensuring call quality.

When APs are deployed in the same physical pattern across floors without channel and physical spacing considerations, co-channel interference (CCI) between floors occurs. This is particularly problematic when APs on different floors are vertically aligned on the same channels.

From CWDP-305:

“In multi-floor deployments, avoid placing APs on the same vertical axis across floors using the same channel. This leads to CCI. Stagger AP locations and vary channels to reduce interference.”

— Reference: CWDP-305 Official Study Guide, Wireless Design Process Chapter

Achieving a 450 Mbps data rate in 802.11n requires specific features:

Short Guard Interval (GI):Reduces the interval between symbols from 800 ns to 400 ns, increasing throughput.

40 MHz Channels:Doubles the channel width compared to 20 MHz, allowing more data to be transmitted.

3 Spatial Streams:Utilizes multiple antennas to transmit separate data streams simultaneously, significantly boosting data rates.

While frame aggregation and transmit beamforming enhance performance and reliability, they are not prerequisites for achieving the 450 Mbps MCS rate.

A client-to-AP link imbalance occurs when the AP's transmit power is significantly higher than that of the client device.This disparity can lead to situations where the client can receive signals from the AP but cannot transmit signals back effectively.This imbalance is particularly problematic in environments where clients have limited transmit capabilities, such as battery-powered devices.To mitigate this issue, it's recommended to adjust the AP's transmit power to match the capabilities of the client devices, ensuring balanced communication.