CWNP CWDP-305 Certified Wireless Design Professional Exam Practice Test

Comprehensive and Detailed Explanation:

In 802.11n, theHigh Throughput Long Training Field (HT-LTF)is utilized by the receiver to estimate the MIMO channel characteristics necessary for demodulating spatially multiplexed signals. The number of HT-LTF symbols corresponds to the number of spatial streams being transmitted. These fields are present in bothMixed ModeandGreenfield Modepreambles.

HT-LTF in Mixed Mode:The preamble includes legacy fields (L-STF, L-LTF, L-SIG) for backward compatibility, followed by HT-specific fields including HT-LTFs for MIMO channel estimation.

HT-LTF in Greenfield Mode:The preamble omits legacy fields and consists solely of HT-specific fields, including HT-LTFs, as there is no need for backward compatibility.

If the number of APs changes due to budget constraints, a complete redesign is required to reevaluate coverage, capacity, and performance expectations. Increasing transmit power or relying on 2.4 GHz is not a valid solution, as it can result in co-channel interference and poor roaming.

From CWDP-305:

“A design is based on specific coverage and capacity requirements. Any major change, such as reducing the number of APs, requires a full redesign to determine the impact and ensure that business requirements can still be met.”

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

Comprehensive and Detailed Explanation:

In the final meeting after successfully implementing a WLAN infrastructure, it is essential to have the acquirer and key stakeholders from the customer side present. The acquirer is typically the individual or group responsible for procuring the WLAN solution, while stakeholders include those who have an interest in the project's success, such as IT managers, network administrators, and department heads. Their presence ensures that the implementation aligns with the organization's requirements and expectations, and it provides an opportunity to address any concerns or questions before project closure.

Channels 116-124 in the 5 GHz band fall under the Dynamic Frequency Selection (DFS) range, which requires devices to vacate the channel if radar signals are detected. Proximity to airports increases the likelihood of radar interference, leading to potential disruptions in Wi-Fi service.

The CWDP-305 Official Study and Reference Guide advises:

"In environments near radar installations, such as airports, it's recommended to avoid DFS channels (e.g., 116-124) to prevent service interruptions due to radar detection requirements."

Comprehensive and Detailed Explanation:

Locating 802.11 clients without dedicated tags relies on the clients actively transmitting signals.If a client's radio is disabled or the device is powered off, it will not emit any signals, making it impossible for the WLAN infrastructure to detect or locate it.While 802.11k support and RF channel selection can affect the accuracy and efficiency of location tracking, they do not prevent the basic ability to detect a client that is actively transmitting.

The Effective Isotropic Radiated Power (EIRP) is calculated using the formula:

Omni Calculator

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EIRP (dBm) = Transmit Power (dBm) + Antenna Gain (dBi) - Cable Loss (dB)

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Assuming negligible cable loss, we first convert the transmit power from milliwatts to dBm:

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Transmit Power = 25 mW = 10 * log10(25) ≈ 14 dBm

Now, adding the antenna gain:

EIRP = 14 dBm + 3 dBi = 17 dBm

Therefore, the EIRP of the APs in this design is 17 dBm.

Comprehensive and Detailed Explanation:

In the "local MAC" variation of the centralized WLAN architecture, all MAC (Media Access Control) functions are performed by the Access Point (AP). A minimal subset of network control is offloaded to the WLAN controller, which also handles management and monitoring functions. This approach allows for more efficient processing at the edge of the network, reducing latency and improving performance.

For long-distance point-to-point wireless links, such as those spanning over 1000 yards, directional antennas are preferred due to their focused beamwidth and higher gain.Yagi antennas are a type of directional antenna known for their high gain and narrow beamwidth, making them suitable for such applications.While panel and patch antennas are also directional, Yagi antennas are specifically designed for long-range communications.

Comprehensive and Detailed Explanation:

When troubleshooting 802.1X/EAP authentication issues, consider the following:

A.Ensure the RADIUS server is online and that the APs and WLAN controllers are configured to communicate with it on the correct port. Misconfigured ports can prevent authentication requests from reaching the server.

C.Verify that the authenticator (e.g., AP or controller) supports the EAP type configured on the client. A mismatch can lead to authentication failures.

D.If using certificate-based EAP methods (like EAP-TLS), confirm that the client's certificate is valid, not expired, and trusted by the RADIUS server. Certificate issues are common causes of authentication problems.

Note:

B.The RADIUS shared secret is configured between the authenticator and the RADIUS server, not on the client (supplicant). Therefore, this option is not applicable.

EAP-TTLS (Extensible Authentication Protocol - Tunneled Transport Layer Security) is an authentication protocol that allows the use of client credentials (such as usernames and passwords) while requiring a server-side certificate. Client-side certificates are optional, making it a flexible solution for environments where deploying certificates to all clients is impractical. This method establishes a secure tunnel between the client and server, ensuring that credentials are protected during the authentication process.

802.11 admission control mechanisms are employed to manage and regulate the bandwidth resources available in a WLAN.By controlling the admission of traffic into the network, these mechanisms ensure that high-priority traffic, such as voice or video, receives the necessary resources for optimal performance.Admission control settings are configured separately for each Access Category (AC), allowing granular control over different types of traffic.

Real-Time Location Systems (RTLS) require precise triangulation, which can only occur if a device is detected by at least three APs with strong RSSI values from various angles. The best accuracy is achieved by placing APs around the perimeter and within the area so devices are surrounded.

From CWDP-305:

“For accurate Wi-Fi location tracking, ensure that client devices can be detected by a minimum of three, preferably four, APs with good signal strength. APs should be placed around the perimeter and within the location zone for proper triangulation.”

— Reference: CWDP-305 Official Study and Reference Guide, Chapter on Designing for Specific Applications

In WLAN operations, two primary scanning methods are employed by client devices to discover available wireless networks:

Active Scanning:The client device actively sends out probe request frames on various channels. Access Points (APs) that receive these requests respond with probe response frames, providing information about the network. This method allows clients to discover networks even if they are not broadcasting their SSIDs.

Passive Scanning:The client device listens for beacon frames that are periodically transmitted by APs. These beacons contain information about the network, such as SSID, supported data rates, and security protocols. Passive scanning is less intrusive and does not generate additional traffic, but it may take longer to discover networks, especially if the beacon interval is lengthy.

Understanding these scanning methods is crucial for network design and troubleshooting, as they impact how quickly and efficiently clients can connect to available networks.

Comprehensive and Detailed Explanation:

Involving end-users in the final meeting ensures that the WLAN infrastructure meets their needs and expectations.Their feedback is crucial for validating the network's performance and usability, as they are the primary users who will interact with the system daily.

Comprehensive and Detailed Explanation:

In WPA2-Enterprise networks, when a client roams from one BSS to another within the same ESS, it must perform 802.1X authentication again unless fast roaming methods like PMK caching or 802.11r are implemented. This step is not required in WPA2-Personal networks, where the pre-shared key (PSK) allows for a quicker transition without re-authentication.

Outdoor antenna installations are particularly susceptible to lightning strikes due to their elevated positions and exposure to the elements.Lightning surge suppressionis essential to protect both the antenna and the connected equipment from the high voltages and currents associated with lightning-induced surges.

Implementing proper lightning protection involves installing surge protectors and ensuring adequate grounding of the antenna system. This not only safeguards the equipment but also enhances the overall reliability and safety of the wireless network infrastructure.

EAP-TLS (Extensible Authentication Protocol - Transport Layer Security) is the most secure EAP type that utilizes certificates for mutual authentication between the client and the server.In this method, both the client and the server present certificates to authenticate each other, eliminating the need for passwords and providing strong security against various attacks.

The CWDP-305 Official Study and Reference Guide emphasizes the importance of using EAP-TLS in environments where strong security is required:

"EAP-TLS is considered one of the most secure EAP types because it uses certificates for both client and server authentication. It provides mutual authentication and is widely supported."

Therefore, for organizations seeking to enhance their WLAN security by moving away from PSK and implementing certificate-based authentication, EAP-TLS is the recommended choice.

Band steering is a technique used to encourage dual-band clients to connect to the less congested 5 GHz band.However, some clients may not respond to steering attempts and persist in attempting to connect on the 2.4 GHz band.To ensure connectivity for these persistent clients, APs are designed to eventually respond to their Probe Requests on the 2.4 GHz band after a certain number of ignored attempts.

The CWDP-305 Official Study and Reference Guide states:

"Band steering mechanisms must account for clients that do not support or respond to steering attempts, allowing them to connect on the 2.4 GHz band after a defined number of ignored Probe Requests."

The Physical Installation Guide is a document that offers step-by-step instructions for technicians on mounting and configuring access points. It includes details such as mounting locations, orientation, cabling requirements, and configuration settings. This guide ensures that APs are installed consistently and according to the design specifications, which is crucial for optimal network performance. Unlike the Statement of Work or Bill of Materials, which outline project scope and equipment lists respectively, the Physical Installation Guide focuses specifically on the practical aspects of AP deployment.

DHCP Option 43 is used to provide vendor-specific information to clients, such as the IP address of a Wireless LAN Controller (WLC).When lightweight access points (APs) need to discover a WLC, configuring DHCP Option 43 allows the APs to obtain the necessary information to locate and join the controller.

The CWDP-305 Official Study and Reference Guide details the use of DHCP Option 43 for AP and WLC communication.

The wavelength (λ) of a radio wave is calculated using the formula:

λ = c / f

Where:

c = speed of light (approximately 3 x 10^8 meters/second)

f = frequency in HzScribd

For 802.11ac operating at 5.5 GHz:Quizlet

λ = 3 x 10^8 / 5.5 x 10^9 ≈ 0.0545 meters ≈ 5.45 cm

This approximates to 5.5 cm (2.16 inches).

The 1 dB compression point of an amplifier indicates the output power level at which the amplifier's gain drops by 1 dB from its linear gain, signaling the onset of non-linear behavior and potential distortion.

Given a 1 dB compression point of 32 dBm and a gain of 20 dB, the maximum linear input power can be calculated as:

32 dBm (compression point) − 20 dB (gain) = 12 dBm

To ensure operation within the linear region and avoid spectral regrowth, it's advisable to operate the amplifier below this threshold.An input power of 0 dBm provides a safe margin, ensuring signal integrity for a 24 Mbps 802.11g transmission.

Comprehensive and Detailed Explanation:

The SKINNY protocol, also known as the Skinny Client Control Protocol (SCCP), is a proprietary protocol used by Cisco for VoIP signaling between endpoints and call managers. Its presence in a protocol capture indicates that VoIP services are active on the network.

Comprehensive and Detailed Explanation:

For reliable Voice over Wi-Fi (VoWiFi) service, a minimum RSSI of -67 dBm is generally recommended. This level ensures sufficient signal strength to support the quality of service required for voice applications, providing adequate signal-to-noise ratio (SNR) and minimizing the likelihood of dropped calls or poor audio quality.

Defining wall materials (e.g., drywall, brick, concrete) in WLAN design software is essential for accurate RF modeling. Different materials attenuate RF signals to varying degrees, and propagation models account for these losses to calculate realistic signal coverage.

From CWDP-305:

“Accurate modeling of RF signal behavior requires defining wall and obstacle materials to account for signal attenuation and reflections. This improves the accuracy of predictive design tools.”

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

In stadium environments where aesthetics are crucial, installing APs in enclosures under seats or on handrails is a common practice.This approach conceals the APs, maintaining the venue's visual appeal while ensuring optimal wireless coverage.

The CWDP-305 Official Study and Reference Guide discusses the importance of aesthetic considerations in WLAN design and recommends discreet installation methods in public venues like stadiums.

Comprehensive and Detailed Explanation:

In designing Point-to-Point (PTP) outdoor wireless links, local vegetation plays a significant role in signal propagation and potential attenuation. Key considerations include:

A. Leaves:Foliage, especially leaves, can absorb and scatter RF signals, particularly at higher frequencies. Seasonal changes can affect signal strength due to varying leaf density.

B. Tree height growth:Over time, trees can grow into the line-of-sight path, causing signal obstruction. Planning should account for potential future growth to maintain clear paths.

C. Water density:Vegetation with high water content can absorb RF energy, leading to increased signal attenuation. This is especially pertinent in areas with lush, dense foliage.

D. Reflection factor:While reflections can impact signal quality, in the context of vegetation, absorption and scattering are more critical factors than reflection.

Upgrading access points (APs) from 802.11n to 802.11ac can offer higher throughput and improved performance. However, to realize these benefits, client devices must also support the newer standard. If the clients remain on 802.11n, they cannot take advantage of 802.11ac features such as wider channels, higher modulation schemes, and beamforming.

Therefore, the most likely reason for the unchanged throughput is that the clients were not upgraded to support 802.11ac.

Comprehensive and Detailed Explanation:

An elevation chart provides a vertical radiation pattern of an antenna, which is essential for understanding how the antenna directs energy above and below the horizon. In bridge link deployments, especially over varying terrains or between buildings of different heights, the elevation pattern helps in aligning antennas to ensure optimal signal propagation and reception. Requesting elevation charts from antenna vendors allows for informed decisions on antenna placement and orientation, leading to more reliable and efficient wireless links.

In the 5 GHz band, all Wi-Fi traffic (802.11a/n/ac/ax) uses OFDM or OFDMA modulation. If multiple APs use overlapping or identical channels, this results in Co-Channel Interference (CCI). Legacy technologies like HR/DSSS and ERP operate in 2.4 GHz and do not contribute to CCI in 5 GHz.

From CWDP-305:

“CCI occurs when multiple devices share the same channel. In 5 GHz, all compliant Wi-Fi traffic uses OFDM-based PHYs, so other nearby OFDM networks are a primary source of CCI.”

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

In public Wi-Fi environments, it's common to implement security measures that prevent clients from communicating directly with each other. This is achieved through peer-to-peer blocking, also known as client isolation. When enabled, this feature ensures that each client can communicate with the AP and access external networks but cannot interact with other clients on the same WLAN.

This setup enhances security by reducing the risk of attacks or unauthorized access between clients.

In wireless communications, lower data rates like 1 Mbps in 802.11b use simpler modulation schemes, allowing them to tolerate higher power levels before distortion occurs. Conversely, higher data rates like 54 Mbps in 802.11g use more complex modulation, which is more susceptible to distortion at high power levels.

When both signals are passed through a saturated amplifier, the 1 Mbps 802.11b signal can handle approximately 5 dB more power than the 54 Mbps 802.11g signal without significant distortion. This difference is crucial in designing systems to ensure signal integrity across varying data rates.

The most accurate method to determine wall attenuation is to perform empirical measurements. First, measure the Received Signal Strength Indicator (RSSI) in free space at a known distance, such as 1 meter (3 feet). Then, place the access point 0.32 meters (1 foot) away from one side of the wall and the measuring device 0.67 meters (2 feet) away on the opposite side. By comparing the RSSI readings from the free space and through the wall, you can calculate the wall's attenuation. This method accounts for real-world variables and provides more accurate data than relying solely on predictive models or manufacturer specifications.

Comprehensive and Detailed Explanation:

Real Time FFT stands for Real Time Fast Fourier Transform.It is a spectrum analysis tool that displays the maximum signal amplitude detected at each frequency in real time.This visualization helps in identifying transient RF events, such as sporadic interference or brief signal spikes, which might not be captured in averaged spectrum analyses.By providing immediate feedback on the RF environment, Real Time FFT graphs are invaluable for troubleshooting and optimizing WLAN performance.

In environments with low Signal-to-Noise Ratio (SNR), maintaining reliable communication becomes challenging due to increased potential for errors.Receive Diversityis a technique employed to enhance signal reception under such conditions.

Receive Diversity involves using multiple antennas at the receiver to capture the same signal.By combining these multiple received signals, the system can mitigate the effects of fading and interference, effectively improving the SNR.This enhancement leads to better throughput as the likelihood of retransmissions due to errors decreases.

Other options like 64-QAM require high SNR to function effectively, and A-MSDU frame aggregation is more beneficial in high SNR environments where larger frames can be transmitted without significant error.

In scenarios where physical access to the ceiling is restricted, such as when ladders are not permitted, using a laser distance measurer is the most accurate and cost-effective method to determine ceiling height. Laser measurers provide precise distance readings by emitting a laser beam to the target surface and calculating the time it takes for the reflection to return. This tool eliminates the need for estimations or indirect calculations, ensuring accurate measurements essential for WLAN design.

CAPWAP and DTLS are the type of standards-based encryption used by office extension APs for the traffic tunnel. Office extension APs are wireless access points that can be deployed in remote locations and connect to a central wireless controller via a secure tunnel over the Internet. CAPWAP is the Control and Provisioning of Wireless Access Points protocol, which defines how the wireless controller and the office extension APs communicate and exchange control and data messages. DTLS is the Datagram Transport Layer Security protocol, which provides encryption and authentication for the CAPWAP tunnel. DTLS is based on TLS, but it uses UDP instead of TCP as the transport layer protocol, which makes it more suitable for real-time applications. DTLS protects the CAPWAP tunnel from eavesdropping, tampering, and replay attacks, and ensures the confidentiality and integrity of the wireless traffic. References: CWNP, CWDP Certified Wireless Design Professional Official Study Guide, Configure OEAP and RLAN on Catalyst 9800 WLC, Hardening Microsoft 365, Office 2021, Office 2019 and Office 2016

Post-implementation deliverables serve to document the final WLAN design, configuration, and layout for the customer’s operational and maintenance teams. The CWDP-305 Study Guide identifies essential deliverables that ensure long-term support, change management, and troubleshooting.

These include:

Floorplans with AP placements and coverage zones

Design documents specifying SSID configuration, channel plans, and power levels

WLAN configuration exports or screenshots for controllers/APs

Inventory lists of installed equipment (serial numbers, models, etc.)

Guides or SOPs for routine WLAN tasks

Providing this documentation is a professional best practice that aligns with design transparency, customer service, and lifecycle management. It enables future audits, upgrades, or expansions while ensuring continuity even if personnel changes.

Comprehensive and Detailed Explanation:

Let's calculate the total loss/gain step by step:

Cable Loss:Each meter reduces the signal by a factor of 4. Over 10 meters:

Total attenuation factor = 4^10 = 1,048,576

In dB: 10 * log10(1,048,576) ≈ 60 dB loss

Amplifier Gain:Output is 8 times the input:

Gain in dB: 10 * log10(8) ≈ 9 dB gain

Filter Loss:Given as 5 dB loss.

Total Loss/Gain:

Total = Cable Loss - Amplifier Gain + Filter Loss

Total = 60 dB - 9 dB + 5 dB = 56 dB loss

However, this calculation leads to 56 dB loss, which is not among the provided options. Let's reassess the cable loss calculation.

Upon reevaluation:

Each meter reduces the signal by a factor of 4, so per meter loss in dB: 10 * log10(4) ≈ 6.02 dB

Over 10 meters: 6.02 dB/m * 10 m = 60.2 dB loss

Now, total loss/gain:

Cable Loss: 60.2 dB

Amplifier Gain: 10 * log10(8) ≈ 9.03 dB

Filter Loss: 5 dB

Total = 60.2 dB - 9.03 dB + 5 dB ≈ 56.17 dB loss

Rounded to the nearest whole number:56 dB loss

Correct Answer:C

Comprehensive and Detailed Explanation:

Using wider channel widths like 80 MHz can increase throughput but also reduces the number of available non-overlapping channels, leading to increased co-channel interference (CCI), especially in dense environments.Reconfiguring APs to use 20 MHz channel-widths enhances frequency reuse and minimizes CCI, thereby improving application performance in an All-Wireless-Office setup.

In WLAN deployments, each SSID is typically mapped to a unique VLAN. This allows logical separation of traffic, enabling different security policies, QoS settings, and routing for different user groups or services.

From CWDP-305:

“Each SSID in a WLAN is usually mapped to a different VLAN on the wired infrastructure. This allows for segregation of traffic, application of different network policies, and enhanced security enforcement.”

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

Each SSID broadcast by an AP adds additional management frame overhead, such as beacon frames. These beacon frames are transmitted periodically by the AP at the lowest mandatory data rate (e.g., 1 or 6 Mbps), which consumes airtime that would otherwise be used for client data.

According to CWDP-305:

“Each SSID increases beacon overhead. More SSIDs lead to greater airtime consumption by management traffic, which in turn decreases available throughput for actual client data traffic.”

Reducing the number of SSIDs is a best practice to minimize management overhead and optimize throughput in the wireless network.

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

In environments where access points (APs) are mounted on high ceilings (e.g., over 20 feet), it's essential to direct the wireless signal downwards towards the client devices on the floor. Patch antennas, which are directional antennas, are ideal for this scenario as they can focus the RF energy downward, providing better coverage and signal strength to the intended area.

The CWDP-305 Official Study and Reference Guide emphasizes the importance of antenna selection based on mounting height and coverage requirements:

"When APs are mounted on high ceilings, using directional antennas like patch antennas can help focus the RF energy towards the client devices, ensuring optimal coverage and performance."

Comprehensive and Detailed Explanation:

In voice over WLAN (VoWLAN) deployments, seamless roaming is critical to maintain call quality. As users move throughout the office, their devices must transition between access points without dropping the call or experiencing latency. Therefore, ensuring efficient and fast roaming capabilities is paramount in the design of a WLAN intended to support voice applications.

The 6 GHz band, introduced with Wi-Fi 6E (802.11ax), mandates the use of WPA3 security protocols. Specifically, WPA3-Personal and WPA3-Enterprise are required for networks operating in this band. WPA2-Personal is not permitted in the 6 GHz spectrum due to regulatory and security requirements.

Therefore, recommending WPA2-Personal for VoIP support in the 6 GHz band is technically inappropriate, as it does not comply with the mandatory security standards for this frequency range.

Maximal Ratio Combining (MRC) is a technique used in MIMO (Multiple Input Multiple Output) systems to improve signal quality by combining multiple received signals. However, 1x1:1 client devices have only one transmit and one receive antenna, making them incapable of utilizing MRC, which requires multiple antennas to combine signals effectively.

The CWDP-305 Official Study and Reference Guide explains:CliffsNotes

"Features like Maximal Ratio Combining, which rely on multiple antennas, are not applicable to single-stream (1x1:1) client devices."

Comprehensive and Detailed Explanation:

Latency is a critical metric when designing WLANs for VoIP (Voice over IP) applications. High latency can result in poor call quality, including delays and echoes. Industry standards recommend that one-way latency should not exceed 150 milliseconds to maintain acceptable voice quality. Therefore, during site surveys and network design, measuring and minimizing latency is essential to ensure a high-quality VoIP experience.

Constraints in network design refer to any limitations that must be worked within during the planning, design, and deployment phases of a project. These constraints shape the decision-making process and ultimately impact the outcome and success of the network.

According to the CWDP-305 Official Study and Reference Guide (Chapter: Wireless Design Process), the following are all common types of constraints:

Timeline: Project deadlines and delivery schedules that limit how long the design or deployment phases can take.

Personnel: Availability of skilled engineers, project managers, and support staff to execute and maintain the design.

Politics: Organizational culture, internal resistance, or conflicting stakeholder priorities that may influence technical decisions.

Budget: Financial limitations that restrict the number or type of components, tools, or services that can be purchased.

“Constraints such as time, money, human resources, and even political considerations are among the most critical factors influencing a WLAN design.”

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

When aesthetics are a concern, one acceptable approach—assuming AP performance and RF behavior will not be affected—is to use manufacturer-approved or specially designed cosmetic covers/skins. These allow the AP to blend into the environment without altering signal propagation.

From CWDP-305:

“Cosmetic or aesthetic AP skins and mounts can be used when design constraints do not permit repositioning APs. These solutions preserve the intended RF coverage while meeting visual requirements.”

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

Mounting location significantly impacts AP radiation patterns and coverage. A wall mount vs. ceiling mount can change signal distribution, SNR, and roaming performance. In such cases, the design assumptions have changed and must be reassessed. Stakeholders must be informed.

From CWDP-305:

“If deviations from the installation design occur, such as AP mounting position changes, the RF environment will likely be affected. The only responsible action is to reassess and, if needed, redesign to meet stated requirements.”

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

Comprehensive and Detailed Explanation:

IEEE 802.3at, also known as PoE+, provides up to 30 watts of power per port. To calculate the minimum Power over Ethernet (PoE) budget required for 6 access points (APs):

30 W/AP × 6 APs = 180 W

Therefore, a switch must have a minimum PoE budget of180 wattsto support six 802.3at-powered APs.

Even when skipping a full pre-design site survey, performing a spectrum analysis walkthrough is considered a best practice. This is because spectrum analysis provides insights into non-Wi-Fi interference sources, such as microwave ovens, Bluetooth devices, cordless phones, and other RF-emitting equipment that may affect WLAN performance.

From CWDP-305:

“A spectrum analysis walkthrough of the facility, even in the absence of a full site survey, can reveal sources of interference that would otherwise go undetected. This step is highly recommended to validate the RF environment.”

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

Comprehensive and Detailed Explanation:

The 802.11 amendments that address regulatory and transmission requirements are:

C. 802.11d:This amendment provides country-specific information, allowing devices to operate in compliance with local regulations regarding frequency use and power levels.

E. 802.11h:Introduced to address spectrum and transmission power management in the 5 GHz band, this amendment includes features like Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC) to mitigate interference with radar systems and adhere to regulatory requirements.

A. 802.11kfocuses on radio resource management.

B. 802.11ipertains to security enhancements.

D. 802.11fdeals with inter-access point protocol for roaming.

The 5 GHz UNII-2 (5.250–5.350 GHz) and UNII-2e (5.470–5.725 GHz) bands are subject to Dynamic Frequency Selection (DFS) regulations due to their shared use with radar systems. If radar activity is detected, devices operating in these bands must cease transmission or switch channels to prevent interference. Therefore, to avoid potential disruptions, it's advisable to steer clear of these bands in environments where radar detection is a concern.

Manual identification of radar pulses using spectrum analysis charts can be challenging because radar signals often have low amplitude at the Wi-Fi receiver, making them difficult to detect visually.This limitation can lead to inaccurate assessments of DFS channel availability.Automated detection methods or using the actual WLAN equipment intended for deployment may provide more reliable results.

Comprehensive and Detailed Explanation:

EAP (Extensible Authentication Protocol) messages are encapsulated withinEAP over LAN (EAPOL)frames when transmitted over 802.11 wireless networks. EAPOL operates at the data link layer and is part of the 802.1X standard, facilitating authentication between the client (supplicant) and the authentication server.

A.EAP-Fast is an EAP method, not the transport mechanism.

B.PEAP is another EAP method that encapsulates EAP within a TLS tunnel.

D.EAP-TLS is an EAP method utilizing TLS for authentication.

Channel 144 in the 5 GHz band is part of the UNII-2 Extended band. Not all 802.11n devices support this channel, as its inclusion came later in the standard's development. Conversely, 802.11ac devices have broader support for 5 GHz channels, including channel 144. Therefore, if the Access Point (AP) is operating on channel 144, 802.11n laptops that do not support this channel will be unable to detect the SSID, while 802.11ac devices will connect without issue.

Comprehensive and Detailed Explanation:

In scenarios where the 2.4 GHz radio is not used for standard access point operations, it can be repurposed for functions such as security monitoring. Utilizing the 2.4 GHz radio for monitoring allows the network to detect unauthorized devices, rogue APs, and potential security threats, thereby enhancing the overall security posture of the wireless network.

When designing a WLAN for applications like Telnet, which are sensitive to latency and require consistent connectivity, it's crucial to minimize co-channel interference.Reducing the AP transmit power helps in creating smaller cells, thereby limiting the overlap between adjacent APs operating on the same channel.This approach reduces contention and interference, ensuring a more stable and reliable connection for latency-sensitive applications.

USB 3.0 interfaces are known to generate RF interference in the 2.4 GHz band due to the high-frequency noise emitted by the differential signaling in USB 3.0 cables and ports. This interference can reduce SNR, especially for devices located close to the USB port.

From CWDP-305:

“USB 3.0 cables and ports can emit broadband noise in the 2.4 GHz band, negatively impacting receive sensitivity and SNR. This can distort measurements during protocol analysis or performance testing.”

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

When working in elevated environments, such as installing APs on ceilings higher than standard heights (e.g., warehouse or industrial sites), safety becomes a critical priority. According to the CWDP-305 Study Guide, proper personal protective equipment (PPE) is essential and typically includes a hardhat to protect from falling objects, a high-visibility vest to ensure visibility among other workers or moving machinery, and a body belt or harness when working at height. These safety requirements are commonly enforced by OSHA and are also discussed in wireless site survey preparation sections.

Comprehensive and Detailed Explanation:

For live video streaming to multiple recipients,Multicastingis an efficient method to deliver the same content simultaneously without consuming additional bandwidth for each recipient. Proper configuration of multicast in WLANs ensures that video streams are transmitted effectively, reducing latency and conserving network resources.

Site survey adapters are often specialized devices with enhanced sensitivity and performance characteristics compared to standard client Wi-Fi adapters.These specialized adapters can detect weaker signals and provide more detailed RF information, leading to higher RSSI readings during surveys.Consequently, standard client devices may experience lower RSSI values in the same environment.

The CWDP-305 Official Study and Reference Guide notes:MetaGeek Community

"Survey adapters are typically more sensitive than standard client devices, which can result in discrepancies between survey data and actual client experiences."

Web-based applicationsare designed to operate over the internet using web browsers. Each user interaction, such as clicking a link or submitting a form, typically results in multiple communications between the client and server. These interactions often involve the transfer of various resources, including HTML files, CSS stylesheets, JavaScript files, images, and other data.

This pattern of frequent back-and-forth communication can place significant demands on network resources, particularly in terms of bandwidth and latency. When designing WLANs to support web-based applications, it's essential to ensure sufficient capacity and performance to handle these demands effectively.

For accurate deployment of access points in a multi-floor indoor environment, providing a camera and marking tools is essential. A camera allows the installation team to reference visual cues from the design, ensuring APs are placed in the correct locations. Marking tools help in identifying precise mounting points on ceilings or walls, facilitating adherence to the design plan. These tools, combined with the design documentation, enable the installation team to execute the deployment accurately, maintaining the integrity of the WLAN design.

Comprehensive and Detailed Explanation:

Not all client devices support the full range of 5 GHz channels.Some devices, especially older ones, may only support the lower UNII-1 band (channels 36–48) and not the higher channels like UNII-2 or UNII-3.If the WLAN infrastructure utilizes channels that the client's device does not support, the device will not detect the SSID on those channels, leading to poor or no connectivity in certain areas.This explains the manager's experience of poor RSSI or lack of connection in specific spots, despite the APs functioning correctly.

Comprehensive and Detailed Explanation:

In a WLAN infrastructure, Quality of Service (QoS) markings, such as User Priority (UP) values, are crucial for prioritizing traffic types like voice.When frames are transmitted from the client to the AP (uplink), the client's QoS settings are applied.However, for downlink traffic (from the AP to the client), the AP relies on QoS markings received from the upstream network.If any device in the wired network path, such as switches or routers, does not trust or properly handle these QoS markings, it can strip or alter them.As a result, the AP may transmit downlink frames without the correct UP values, leading to degraded voice quality.

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.

In environments where access points (APs) are mounted on high ceilings (over 6 meters), it's essential to choose an antenna that provides adequate coverage to client devices located at floor level. A low-gain dipole antenna is vertically polarized and offers an omnidirectional radiation pattern, which is suitable for such scenarios. Its radiation pattern ensures that the signal is distributed evenly in all horizontal directions, providing consistent coverage to devices below.

Other antenna types like patch, dish, and grid are more directional and may not provide the necessary coverage for clients spread across the floor area.

In an independent autonomous architecture, each AP operates independently without coordination with other APs.This lack of centralized control or coordination mechanisms limits the ability to share control information, such as client roaming data or RF management decisions, across APs.As a result, features like seamless roaming and dynamic RF adjustments are challenging to implement effectively in such architectures.

When designing a wireless bridge over a distance of 13 kilometers, it's crucial to account for the Earth's curvature, known as the "Earth bulge," which can obstruct the Fresnel Zone and degrade the signal.The Fresnel Zone is an elliptical area around the line of sight between two antennas, and any obstruction within this zone can cause signal diffraction and attenuation.

The CWDP-305 Official Study and Reference Guide highlights this consideration:

"For long-distance point-to-point links, the Earth’s curvature becomes a factor, and the Fresnel Zone must be clear of obstructions, including the Earth bulge, to maintain signal integrity."

Therefore, when planning such links, engineers must calculate the Fresnel Zone and ensure that the Earth bulge does not intrude into this zone, possibly requiring higher antenna placements or alternative solutions.

Comprehensive and Detailed Explanation:

Business requirements typically focus on objectives that directly impact the organization's performance, efficiency, and profitability. Options A, B, and D align with these goals:

A.Improving employee productivity enhances operational efficiency.

B.Cutting operating expenses reduces costs, increasing profitability.

D.Supporting 802.11n ensures the network meets current technological standards, improving performance.

C."Making employees happy to come to work" is more of a cultural or human resources goal and doesn't directly pertain to the technical or financial objectives of a network design. Therefore, it's not considered a business requirement in this context.

In 802.1X/EAP authentication, the shared secret between the authenticator and the RADIUS server must match. If clients cannot associate and the RADIUS server is operational, the next step is to verify that the shared secret configured on both the authenticator and the RADIUS server is identical. A mismatch will prevent successful authentication.

In Voice over WLAN (VoWLAN) deployments, it's crucial to differentiate between various types of voice-related traffic to ensure optimal Quality of Service (QoS).Real-Time Protocol (RTP) carries the actual voice payload, while control protocols like RTCP manage session control and quality feedback.Assigning distinct priority levels to these traffic types allows the network to prioritize voice payloads appropriately while still handling control traffic efficiently.

Comprehensive and Detailed Explanation:

The IEEE 802.11 standard does not mandate a specific calibration accuracy for Received Signal Strength Indicator (RSSI) and Signal-to-Noise Ratio (SNR) reporting across client devices. RSSI values are relative and can vary between different hardware vendors, as each manufacturer may implement their own scale and measurement methods. This lack of standardization means that RSSI readings are not directly comparable across different devices. Therefore, there is no specific value to which clients are required to be calibrated for RSSI and SNR reporting.

In wireless RF mathematics, conversion between dBm (a logarithmic unit) and milliwatts (a linear power unit) is a foundational skill. The correct formula to convert a known dBm value to its equivalent in milliwatts (mW) is:

mW = 10^(dBm / 10)

This formula expresses the inverse of converting from mW to dBm (which is: dBm = 10 × log10(mW)).

For example:

0 dBm = 10^(0/10) = 1 mW (which is a known reference point in RF)

This allows for easy conversion of power levels in wireless design, helping to determine link budgets, path losses, and power limits.

Incorrect options:

A is a correct statement (0 dBm = 1 mW), but not a conversion formula.

B and C are incorrect algebraically and do not represent logarithmic conversion principles.

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.

To validate fast roaming (802.11r), a protocol analyzer is required to capture authentication frames and reassociation frames between APs. These allow you to verify if fast BSS transitions are occurring and if the endpoint is participating in FT.

From CWDP-305:

“Fast BSS Transition (802.11r) validation requires capturing EAP exchanges and reassociation frames during roaming. A protocol analyzer with multiple adapters can monitor channels simultaneously during transitions.”

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

A Master Services Agreement (MSA) is a foundational contract that outlines the terms and conditions between parties for future transactions or services. Two critical legal categories typically addressed in an MSA are:

Nondisclosure Agreement (NDA):This clause ensures that confidential information shared between parties remains protected and is not disclosed to unauthorized entities.

Indemnity Clause:This provision stipulates that one party will compensate the other for certain damages or losses, safeguarding against potential legal liabilities arising from the agreement.

These clauses are essential for establishing trust and clarity in business relationships, ensuring that both parties understand their responsibilities and protections under the agreement.

Comprehensive and Detailed Explanation:

IEEE 802.3at, also known as PoE+, provides up to 25.5 watts of power per port. To support 6 access points requiring PoE+ power:

25.5 W/AP × 6 APs = 153 W

Considering some overhead for power loss and future scalability, a minimum PoE budget of 180 W is recommended to ensure reliable operation.

Detecting interference during a spectrum analysis walkthrough is a critical part of WLAN design. The appropriate action is to record the details using the spectrum analyzer’s logging features or document it for later assessment.

From CWDP-305:

“When interferers are discovered during a walkthrough, they should be recorded and investigated. This documentation helps in adjusting AP placement, channel assignment, or applying mitigation strategies during the design process.”

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

Comprehensive and Detailed Explanation:

In wired networks, VLANs effectively segment traffic into separate broadcast domains, isolating traffic between different VLANs. However, in wireless networks, while VLANs are used to assign different SSIDs to different VLANs, the wireless medium is inherently shared. This means that, despite VLAN assignments, all wireless traffic is transmitted over the same RF medium, and clients can still hear all transmissions. Therefore, wireless VLANs do not always provide the same level of traffic segmentation as wired VLANs.

If QoS markings are correct from the client to the AP but incorrect from the AP to the client, it's likely that the QoS markings are being stripped or not trusted somewhere on the wired network between the controller and the AP. This misconfiguration can result in the AP transmitting frames without the appropriate QoS markings, affecting voice quality.

In environments where both WMM-PS (Wi-Fi Multimedia Power Save) certified and non-WMM-PS client devices coexist, disparities in performance and battery life can occur. WMM-PS enhances power-saving mechanisms by allowing devices to enter low-power states and schedule transmissions efficiently. Non-WMM-PS devices, lacking this capability, rely on traditional power-saving methods like PS-Poll, which are less efficient. As a result, WMM-PS devices benefit from improved battery life and performance, while non-WMM-PS devices may experience reduced efficiency.

Any deviation from the RF design plan, including changes in AP placement, can significantly impact the performance and coverage of the WLAN.Therefore, it's crucial to consult the RF designer before making any alterations.The RF designer can assess the proposed changes and determine if they align with the overall network design objectives or if adjustments are necessary to maintain optimal performance.

Remote Authentication Dial-In User Service (RADIUS) is a networking protocol that provides centralized Authentication, Authorization, and Accounting (AAA) management for users who connect and use a network service.When integrating with an LDAP directory, RADIUS servers can authenticate users against the LDAP database before granting access to the WLAN infrastructure.

The CWDP-305 Official Study and Reference Guide notes:

"What service must be implemented on your customer's network to authenticate users against an LDAP database before granting access to the WLAN infrastructure? B. RADIUS"Pass4Success

In North America, Wi-Fi devices operating in the 2.4 GHz band are typically restricted to channels 1 through 11. However, in Europe, channels 12 and 13 are also permitted. If a European AP is configured to operate on channel 13, a North American device may not recognize or connect to it, leading to low RSSI readings or inability to connect.

Passei Direto

How-To Geek

In this scenario, the AP in the room is likely operating on channel 13, which the traveler's device cannot utilize, resulting in low RSSI. Conversely, the lobby APs are operating on channels 1 through 11, which are compatible with the traveler's device, leading to normal RSSI readings.

Other options, such as the AP using ZigBee or Bluetooth, are unlikely, as these technologies are distinct from Wi-Fi and would not present as Wi-Fi SSIDs. The switchport speed, while affecting throughput, does not directly impact RSSI.

Comprehensive and Detailed Explanation:

iPerf is a widely used network testing tool that measures the maximum achievable bandwidth on IP networks. In the context of wireless site surveys and validation, iPerf is utilized to perform throughput testing, providing insights into the data transfer rates between devices. This information is vital for assessing the performance of the wireless network and ensuring it meets the required specifications.

When designing a WLAN infrastructure, it's essential to calculate the Power over Ethernet (PoE) budget accurately to ensure all Access Points (APs) receive sufficient power. IEEE 802.3at, also known as PoE+, provides up to 30 watts of power per port. Therefore, for 6 APs:

6 APs × 30 W = 180 W

This calculation assumes that each AP requires the full 30 W provided by IEEE 802.3at and that there are no additional power losses or overheads. It's always a good practice to include a buffer in real-world scenarios to account for power losses in cables and potential future expansions.Quizlet

Comprehensive and Detailed Explanation:

Voice over WLAN (VoWLAN) applications are sensitive to packet loss, which can degrade call quality. An acceptable packet error rate (PER) for VoWLAN is typically no more than 1%. Maintaining a PER at or below this threshold ensures that voice communications remain clear and intelligible, minimizing the impact of lost packets on the user experience.

In environments with high-security restrictions, such as meat processing facilities, it's imperative to obtain the necessary access and clearance before conducting a site survey.This ensures compliance with security protocols and prevents unauthorized access to sensitive areas.

The CWDP-305 Official Study and Reference Guide emphasizes the importance of adhering to site-specific security requirements during site surveys.

The maximum theoretical signal gain of chip-based TxBF and MRC depends on the number of antennas and the channel conditions. TxBF (transmit beamforming) is a technique that focuses the transmitted signal in the direction of the intended receiver, resulting in higher signal strength and less interference. MRC (maximum ratio combining) is a technique that combines the signals received by multiple antennas in an optimal way, resulting in higher signal-to-noise ratio and better performance. The theoretical gain of TxBF and MRC can be calculated as

GTxBF​=10log10​(N)

and

GMRC​=10log10​(N)

where N is the number of antennas. Therefore, the total gain of TxBF and MRC is

Gtotal​=GTxBF​+GMRC​=20log10​(N)

However, this is the ideal case and assumes perfect channel conditions and alignment. In reality, the gain is lower due to factors such as channel fading, antenna spacing, and feedback delay.According to the CWDP study guide1, the typical gain of TxBF and MRC is about 4-6.5 dBi for 2 antennas, 7-10 dBi for 3 antennas, and 10-13 dBi for 4 antennas.Therefore, the answer is D.References:1: CWDP Certified Wireless Design Professional Official Study Guide: Exam PW0-250, Chapter 8, page 267.

Jitter and latency are two important metrics for measuring the quality and performance of wireless networks, especially for real-time applications such as voice and video. Latency is the average time taken for a data packet to reach the destination, while network jitter is the irregularity in latency. When the latency is consistently high, it can mean a slow but stable connection. On the other hand, a high jitter means there may be sporadic disruptions or delays in the transmission, which can affect the quality of service and user experience. Jitter is caused by various factors, such as network congestion, interference, routing changes, hardware issues, or packet prioritization. Jitter can be measured by calculating the difference between the latency of two consecutive packets, or by using the standard deviation of the latency of a sample of packets. Jitter can be reduced by using Quality of Service (QoS) mechanisms, such as traffic shaping, queuing, or scheduling, which can prioritize the packets based on their importance and sensitivity to delay. Jitter can also be mitigated by using jitter buffers, which can store the incoming packets and smooth out the variations in latency before delivering them to the application. References: CWNP, CWDP Certified Wireless Design Professional Official Study Guide, Network Jitter - Common Causes and Best Solutions, Network Jitter vs Latency: What’s the Difference and Why Does It Matter, Jitter vs Latency - What’s The Difference and Why it Matters

Lower data rates, such as 1 Mbps, use simpler modulation schemes (e.g., BPSK) which are more robust against noise and require lower signal-to-noise ratios (SNR) for successful reception.This means that frames transmitted at lower data rates can be received over longer distances compared to higher data rates like 54 Mbps, which use more complex modulation schemes (e.g., 64-QAM) that require higher SNR and are more susceptible to signal degradation.