CWDP-305 CWNP Certified Wireless Design Professional Free Practice Exam Questions (2025 Updated)

The IEEE 802.11-2016 standard specifies two methods for Fast BSS Transition (FT) to facilitate fast and secure roaming:mrn-cciew

Over-the-Air (OTA):The client communicates directly with the target AP to perform the authentication exchange during roaming.

Over-the-Distribution System (Over-the-DS):The client communicates with the current AP, which then communicates with the target AP over the distribution system to perform the authentication exchange.

These methods are designed to reduce the time required for re-authentication during roaming, ensuring minimal disruption to ongoing sessions.

The CWDP-305 Official Study and Reference Guide states:

"802.11r defines two methods for fast BSS transition: Over-the-Air and Over-the-DS, both aimed at reducing latency during client roaming."

Comprehensive and Detailed Explanation:

In WLANs, excessive retransmissions of Real-time Transport Protocol (RTP) frames, often due to interference or poor signal quality, can trigger the rate adaptation algorithm in client devices. This algorithm reduces the data transmission rate to maintain connectivity, which can lead to increased latency and degraded voice quality.

Comprehensive and Detailed Explanation:

High Rate Direct Sequence Spread Spectrum (HR/DSSS) is associated with the IEEE 802.11b standard, which specifies the following physical layer (PHY) data rates:

1 Mbps and 2 Mbps:Achieved using Differential Binary Phase Shift Keying (DBPSK) and Differential Quadrature Phase Shift Keying (DQPSK) modulation techniques, respectively.

5.5 Mbps and 11 Mbps:Achieved using Complementary Code Keying (CCK) modulation, which allows higher data rates while maintaining robustness against interference.

These rates are specific to the 802.11b standard operating in the 2.4 GHz band.

Interference primarily affects the receiver's ability to demodulate signals. In a point-to-point link, RF interference occurring at the middle of the link has little to no impact unless it reaches either endpoint. Therefore, the focus must be on minimizing interference at the receivers.

From CWDP-305:

“Interference at the receiver is the key concern in bridge links. The energy must be received cleanly to enable demodulation, so interference near the receiving AP is more critical than in the link’s midspan.”

— Reference: CWDP-305 Official Study and Reference Guide, Chapter on ProtocolandSpectrum Analysis

Before integrating an access point (AP) into a production environment, it's imperative to apply a baseline configuration. This configuration ensures that the AP adheres to the organization's security policies and network standards, mitigating potential vulnerabilities upon deployment. Implementing a baseline configuration aids in maintaining network integrity and simplifies future troubleshooting.

160 MHz channels consume a large portion of the available spectrum. Due to DFS and regulatory limitations, very few 160 MHz-wide channels are available in the 5 GHz band. This makes them impractical for most enterprise environments where avoiding interference and ensuring channel reuse are critical.

From CWDP-305:

“Due to the limited number of non-overlapping 160 MHz channels in the 5 GHz band—and DFS limitations—these channels are difficult to deploy in enterprise WLANs. This limits their usefulness in dense environments.”

— Reference: CWDP-305 Official Study and Reference Guide, Chapter on ProtocolandSpectrum Analysis

Comprehensive and Detailed Explanation:

For Voice over IP (VoIP) over WLAN, seamless roaming is critical to maintain call quality. To achieve this:

D.Ensuring that at least two access points (APs) are visible with adequate signal strength from any location allows client devices to roam between APs without dropping the connection. This overlap facilitates smooth handoffs and maintains call continuity.

A.While measuring cell overlap is useful, the key is to design the network to provide the necessary overlap, not just measure it.

B.Increasing output power can lead to larger cells but may cause interference and reduce the number of available channels, which is counterproductive in dense environments.

C.Higher gain antennas focus the signal, which may not provide the desired omnidirectional coverage needed for consistent overlap.

Comprehensive and Detailed Explanation:

Mounting APs above the ceiling can significantly degrade WLAN performance due to signal attenuation and unpredictable RF propagation.If aesthetic constraints were not communicated during the requirements gathering phase, the design likely does not account for the additional attenuation caused by ceiling materials.Therefore, it's essential to inform the stakeholder that the current deployment does not meet performance requirements and that a redesign is necessary to address the unforeseen constraints.Pass4Success

Comprehensive and Detailed Explanation:

Designing a guest network in a large enterprise involves several considerations to ensure security, performance, and user experience:

Rate limiting:Implementing bandwidth controls prevents guest users from consuming excessive network resources, ensuring that corporate users maintain optimal performance.

Traffic tunneling or anchoring:Redirecting guest traffic through a centralized point (such as a DMZ or a dedicated internet connection) isolates it from the corporate network, enhancing security.

SSID segmentation:Using separate SSIDs for guest and corporate networks allows for distinct policy enforcement, access controls, and network segmentation.

Option A:While 802.11n provides higher throughput, it's a standard feature and not a specific design consideration for guest networks.

Option C:802.1X security is typically used for enterprise networks requiring individual authentication. Guest networks often use simpler authentication methods like captive portals.

In the context of High-Level Design (HLD) documents within wireless network design, the primary audiences typically include operations teams, designers, and engineering personnel. These stakeholders are directly involved in the planning, implementation, and maintenance of the network infrastructure.

Executives, while important decision-makers, are not the primary audience for HLDs. Instead, they are more likely to engage with executive summaries or business case documents that highlight the strategic and financial implications of the network design, rather than the technical specifics detailed in HLDs.

When calculating the total noise figure of cascaded components, Friis' formula is used:

F_total = F1 + (F2 - 1)/G1 + (F3 - 1)/(G1 × G2) + ...

Where:

F_totalis the total noise factor (linear, not in dB).

F1, F2, ...are the noise factors of the individual stages.

G1, G2, ...are the gains of the preceding stages (linear, not in dB).

In this scenario, the amplifier has a gain of 0 dB, which corresponds to a linear gain of 1. A noise figure of 10 dB corresponds to a noise factor of 10. Assuming the cable and filter have negligible noise contributions or are passive components with minimal loss, their impact on the total noise figure is minimal.

Applying Friis' formula:

F_total = 10 + (1 - 1)/1 = 10

Converting back to dB:

NF_total = 10 × log10(10) = 10 dB

Configuration backups are a critical component of operational and maintenance plans.They ensure that, in the event of a failure or misconfiguration, the network can be restored to a known good state quickly.Despite their importance, configuration backups are often overlooked, leading to prolonged downtimes and increased recovery times during network issues.

Centralized data forwarding means all wireless traffic is tunneled back to a central controller, which handles tasks such as filtering, firewalling, and policy enforcement.

From CWDP-305:

“Centralized data forwarding enables consistent policy enforcement and traffic filtering by handling all traffic at the controller rather than at individual APs.”

This approach provides better control and visibility, especially in environments with strict security and traffic management requirements.

— Reference: CWDP-305 Official Study and Reference Guide, Chapter on Infrastructure Design

To determine the minimum RSSI required for a VoWLAN deployment with a specified SNR, use the formula:

Minimum RSSI = Noise Floor + Required SNR

Given:

Required SNR = 25 dB

Noise Floor = -88 dBm

Calculation:

Minimum RSSI = -88 dBm + 25 dB = -63 dBm

Thus, the minimum RSSI needed is -63 dBm.

Explanation with Extract:

Per the *CWDP-305 Study Guide*, Voice over WLAN (VoWLAN) deployments require robust signal quality. The SNR is critical for voice performance, and the guide specifies:

"For VoWLAN, an SNR of 25 dB is typically required to ensure clear voice quality and minimal latency."

"The minimum RSSI is derived by adding the required SNR value to the measured noise floor."

This aligns with RF fundamentals where SNR is the difference between the received signal strength (RSSI) and the ambient noise floor. A higher SNR (e.g., 25 dB for voice) demands a stronger signal relative to noise. Here, a noise floor of -88 dBm plus 25 dB SNR results in -63 dBm RSSI (Option D).

Why other options fail:

A. -70 dBm: Results in 18 dB SNR (−70 − (−88) = 18 dB), insufficient for VoWLAN.

B. -67 dBm: Yields 21 dB SNR (−67 − (−88) = 21 dB), below the 25 dB requirement.

C. -65 dBm: Provides 23 dB SNR (−65 − (−88) = 23 dB), still inadequate.