CWDP-305 Certified Wireless Design Professional Questions and Answers

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.

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.

Comprehensive and Detailed Explanation:

When calibrating a floor plan for predictive and manual site surveys, using the longest available measurement, such as a straight exterior wall, provides the most accurate and reliable RF data.Longer measurements reduce the impact of scaling errors, ensuring that the entire floor plan is accurately represented in the survey software.Shorter measurements, like those of a single ceiling tile or doorway, can introduce significant scaling errors over larger distances.

Comprehensive and Detailed Explanation:

In a Point-to-Multipoint (PtMP) setup where one building serves as the central hub (root bridge) connecting to multiple other buildings arranged in a square, a100° sector antennais ideal. This type of antenna provides a wide coverage area, allowing it to effectively communicate with all the other buildings positioned around it. Sector antennas focus the RF energy in a specific direction, offering better performance and reduced interference compared to omni-directional antennas in such scenarios.

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.

The Physical Installation Guide is developed during the design phase and delivered to the installation team. It contains detailed AP locations (including mounting heights and orientations), cabling instructions, hardware installation standards, and any specific AP configuration notes needed during physical deployment.

From CWDP-305:

“A Physical Installation Guide provides specific instructions to installers, such as mounting height, orientation, and any environmental considerations. This ensures that APs are installed correctly and according to the design.”

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

After deploying a WLAN as per the design specifications, conducting a post-installation survey is crucial.This survey verifies that the implemented network meets the design objectives, such as coverage, capacity, and performance.It helps identify any discrepancies between the predicted and actual performance, allowing for necessary adjustments to optimize the WLAN.

Accurate WLAN design relies heavily on the precision of the floor plan used in predictive modeling tools. Before placing Access Points (APs), antennas, or defining attenuation factors, it's imperative to calibrate the floor plan. This involves setting a known scale, typically by measuring a known distance within the plan, to ensure that the software accurately represents real-world dimensions.

Proper calibration ensures that signal propagation, coverage areas, and interference zones are accurately predicted, leading to a more reliable and efficient WLAN design.

Comprehensive and Detailed Explanation:

The 2.4 GHz band has only three non-overlapping channels: 1, 6, and 11.Using other channels can lead to overlapping and interference.To prevent this, the automatic channel assignment settings should be configured to use only channels 1, 6, and 11, ensuring minimal overlap and optimal performance.

To authenticate users against an LDAP database for WLAN access, a RADIUS (Remote Authentication Dial-In User Service) server must be implemented. RADIUS acts as an intermediary between the WLAN infrastructure and the LDAP directory, facilitating authentication requests. When a user attempts to connect to the WLAN, the access point forwards the authentication request to the RADIUS server, which then queries the LDAP directory to verify the user's credentials. This integration ensures centralized authentication and enhances security by leveraging existing directory services.

Conducting a post-deployment survey before all APs are installed—particularly in a multi-floor environment—may yield incomplete results. APs from other floors can influence coverage (due to bleed-through floors), roaming behavior, and channel planning, so the validation should ideally happen after full deployment.

From CWDP-305:

“In multi-floor environments, APs from upper and lower floors contribute to the RF landscape. Validation should wait until all APs are installed to evaluate the WLAN's full performance characteristics.”

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

This is a classic example of a WLAN designed for coverage but lacking capacity. Simply adding more APs without proper planning (option C) or increasing output power (option D) would likely lead to channel contention, co-channel interference, and degraded performance.

A proper redesign would include:

Evaluating user density

Planning for spatial reuse

Implementing low-power, high-density AP placement

Selecting appropriate channels and RF tuning

From CWDP-305:

“High-density environments such as auditoriums require WLANs designed for capacity, not just coverage. This includes AP placement optimization, channel planning, and potentially microcell designs to manage client load effectively.”

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

Comprehensive and Detailed Explanation:

Return loss measures how well devices or lines match impedance, with higher values indicating better matching and less signal reflection. When measuring return loss through a cable with known loss, the actual return loss of the antenna is calculated by subtracting twice the cable loss from the measured value:

Measured return loss = 20 dB

Cable loss = 2.5 dB

Actual return loss = 20 dB - (2 × 2.5 dB) = 15 dB

However, since the question states the measured value is "larger than 20 dB," let's assume it's, for example, 22.5 dB:

Actual return loss = 22.5 dB - (2 × 2.5 dB) = 17.5 dB

An actual return loss of17.5 dBis considered acceptable and indicates a reasonably good impedance match, minimizing signal reflections.

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.

A Non-Disclosure Agreement (NDA) is a legal contract that establishes a confidential relationship between parties. In the context of WLAN design, it ensures that any proprietary information shared by the customer during the information-gathering phase remains confidential and is not disclosed to unauthorized parties.

Non Disclosure Agreements

The Statement of Work (SoW) outlines the tasks and deliverables of the project but does not address confidentiality.

The Bill of Materials (BoM) lists the required components for the project but does not pertain to information protection.

A Hold Harmless agreement typically pertains to liability and indemnification, not confidentiality.

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.

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.

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.

Comprehensive and Detailed Explanation:

The 5 GHz band offers more non-overlapping channels and is less susceptible to interference compared to the 2.4 GHz band. By moving corporate data clients and VoWiFi devices to the 5 GHz band, the network can achieve better performance and reduced interference, especially for latency-sensitive applications like voice over Wi-Fi.

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.

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.

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:

Mounting APs above the ceiling can significantly degrade WLAN performance due to signal attenuation caused by ceiling materials and obstructions. If aesthetic requirements were not communicated during the initial requirements gathering, the current deployment does not align with the documented design specifications. The appropriate course of action is to inform the stakeholder that the WLAN performance requirements may not be met under the current installation and that a new design process is necessary to address the aesthetic constraints while ensuring optimal performance.

An AP-on-a-Stick survey is a method of validating a predictive design by placing an AP at each proposed location and measuring the signal coverage and performance. This allows the designer to verify the accuracy of the predictive design and make any adjustments if needed. An AP-on-a-Stick survey is more cost-effective and time-efficient than deploying all the APs and performing a passive or active site survey, which would require installing the APs, cabling, power, and network infrastructure. Using a client device to measure the signal from the APlocations is not a reliable way of validating the design, as it does not account for the interference, noise, and multipath effects that may affect the actual AP performance. References: 1: CWDP Certified Wireless Design Professional Official Study Guide: Exam PW0-304, Chapter 5, page 163.

For cable runs exceeding 55 meters (180.5 feet) and to support 802.3bz MultiGig speeds (2.5GBASE-T and 5GBASE-T), it's recommended to use Cat-6a cabling. Cat-6a cables are designed to handle higher frequencies and provide better performance over longer distances compared to Cat-5e or Cat-6, making them suitable for MultiGig applications.

The CWDP-305 Official Study and Reference Guide highlights the importance of selecting appropriate cabling to support higher data rates:

"When deploying MultiGig Ethernet, especially for cable lengths exceeding 55 meters, Cat-6a cabling is recommended to ensure reliable performance and compliance with standards."

Wi-Fi Multimedia (WMM) is a feature that enables Quality of Service (QoS) on 802.11 networks, allowing for the prioritization of different types of traffic such as voice, video, and data. If WMM is not enabled, the network cannot differentiate or prioritize traffic types, leading to potential performance issues, especially for latency-sensitive applications like VoIP or video conferencing. Therefore, without WMM, 802.11 QoS functionalities are unavailable, impacting the overall efficiency and user experience of the WLAN.

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

Comprehensive and Detailed Explanation:

An LLD (Low-Level Design) document contains technical specifications and granular configuration details about the WLAN infrastructure. This includes VLAN mappings, IP address schemes, and what network devices (e.g., switches or routers) are responsible for routing between VLANs.

“LLD” is the correct type of document to specify VLAN configuration in detail.

“Routing” is the correct function when VLANs must communicate with each other across subnets, and the document should indicate which devices perform inter-VLAN routing.

“The Low-Level Design includes VLAN assignments, routing roles, IP schemas, and all technical details that installers and engineers need to configure the system.”

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

Comprehensive and Detailed Explanation:

Virtual Private Networks (VPNs) are commonly employed in WLANs for:

Remote AP tunneling to a corporate WLAN controller or VPN concentrator:This allows remote access points (APs) to securely connect back to the corporate network over the internet, ensuring that data traffic is encrypted and secure.

Client device connectivity to corporate resources from unsecured public networks:VPNs enable client devices to securely access corporate resources when connected to public or unsecured networks, protecting sensitive data from potential threats.

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.

Comprehensive and Detailed Explanation:

Enabling the "Validate server certificate" option is a critical security measure when configuring Extensible Authentication Protocol (EAP) types, such as EAP-TLS or PEAP. This setting ensures that the client verifies the authenticity of the RADIUS server's certificate during the authentication process, preventing man-in-the-middle attacks. By validating the server certificate, clients can confirm they are connecting to a legitimate network, thereby maintaining the integrity and security of the WLAN.

Microsoft Learn

Comprehensive and Detailed Explanation:

In predictive modeling for WLAN design:

B.Setting the AP transmit power to match the average client device capabilities (e.g., 25 mW) ensures a balanced link budget, promoting reliable two-way communication and accurate coverage predictions.

A.While default antenna patterns can be used, they may not accurately represent the actual deployment, especially if different antennas are planned.

C.Channel width settings should reflect the intended deployment plan, which may include 20 MHz, 40 MHz, or 80 MHz channels, depending on the environment and requirements.

D.Using pre-configured vendor-specific AP and antenna models in the predictive software ensures that thesimul-ationclosely matches the actual hardware characteristics, leading to more accurate predictions.

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."

Barcode scanners are typically used in retail, logistics, and warehouse environments to transmit small amounts of data (e.g., scanned UPC codes) to backend systems. Therefore, their throughput requirements are minimal.

From CWDP-305:

“Barcode scanners and similar IoT devices typically transmit small packets at low intervals and have very low throughput requirements. WLAN design for such devices should focus on coverage and roaming, not capacity.”

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

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.

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.

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.

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.

To calculate the required transmit power (Tx Power) for a desired Effective Isotropic Radiated Power (EIRP), the following formula is used:

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

Given:

Desired EIRP: 21 dBm

Antenna Gain: 5.85 dBd (which is approximately 8 dBi, since 0 dBd = 2.15 dBi)

Cable Loss: (25 feet / 100 feet) * 4 dB = 1 dB

Plugging into the formula:

21 dBm = Tx Power + 8 dBi - 1 dB

Tx Power = 21 dBm - 8 dBi + 1 dB = 14 dBm

Converting 14 dBm to milliwatts:

10^(14/10) ≈ 25.12 mW

However, since 14 dBm is approximately 25 mW, the closest answer is:

Answer:D

A WLAN scanner (e.g., inSSIDer, WiFi Analyzer) is a simple, often free or low-cost tool that scans the air for available SSIDs and channels. It is used for basic visibility of neighbor WLANs, including SSID names, signal strengths, and channels in use.

From CWDP-305:

“WLAN scanners are useful for identifying neighboring WLANs, SSIDs, and basic RF characteristics. While not as detailed as professional survey tools, they are sufficient for quick checks.”

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

In wireless site surveys, especially when using predictive modeling tools,calibrationis a critical step to ensure that the simulated RF coverage accurately reflects the real-world environment.

Calibration involves measuring actual signal strengths at various locations within the environment and adjusting thesimul-ationparameters accordingly. This process accounts for real-world factors such as wall materials, furniture, and other obstructions that can affect signal propagation.

Failing to calibrate thesimul-ationcan lead to discrepancies between predicted and actual coverage, potentially resulting in poor network performance and user experience.

In environments like museums, aesthetic considerations are paramount. To maintain the visual integrity of exhibits while ensuring robust wireless coverage, APs can be concealed using plastic covers that match the surroundings. These covers are designed to be RF-transparent, ensuring that signal strength and quality are not compromised.

Other options are less suitable:

Locking the AP inside a metal box would severely attenuate the wireless signal due to the shielding effect of metal.

Placing APs between walls and I-beams may obstruct signal propagation and complicate maintenance.

Using outdated technology like 802.11b APs would not meet modern performance standards and could introduce compatibility issues.

A switch has a limited power budget that dictates how many PoE devices it can support at once. Even if the cable is functional and supports data (as seen with the laptop test), the switch may have exhausted its PoE budget, making it unable to provide power to additional devices. The CWDP-305 Study Guide highlights the importance of understanding power budgets when designing and deploying infrastructure, especially with newer AP models that draw more power under 802.3at or 802.3bt.

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

Antenna gain is a measure of how well an antenna directs or concentrates radio frequency energy in a particular direction. Higher gain antennas focus energy more narrowly, resulting in longer range and better signal strength in the targeted direction.

4λ Dipole:Typically offers modest gain and is omnidirectional, making it unsuitable for high-gain requirements.

Yagi:Provides moderate directional gain, generally up to around 20 dBi.

Horn:Offers directional gain, but usually not exceeding 20-25 dBi.

Dish:Parabolic dish antennas are designed for very high gain applications, often exceeding 30 dBi. They are ideal for point-to-point links over long distances.

Therefore, to achieve a gain of 35 dBi, a dish antenna is the appropriate choice.

Comprehensive and Detailed Explanation:

Modulation is the technique of varying a carrier signal's properties—such as amplitude, frequency, or phase—to encode and transmit data. This process allows the transmission of information over various mediums, including radio frequencies used in wireless communications.

Option A:Describes spread spectrum techniques, not modulation.

Option B:Is a partial description but lacks the specificity of how the carrier is modified.

Option D:Is a vague statement that doesn't accurately define modulation.

Comprehensive and Detailed Explanation:

Hiding the Service Set Identifier (SSID) can serve specific purposes, such as:

Preventing guests from attempting to join the secured corporate network:By not broadcasting the corporate SSID, casual users are less likely to attempt connections, reducing unauthorized access attempts.

Minimizing help desk calls from users and guests attempting to join the wrong network:When only the guest network SSID is visible, it simplifies the connection process for visitors, leading to fewer support requests.

However, it's important to note that SSID hiding is not a robust security measure. Determined attackers can still detect hidden networks using various tools, as the SSID can be revealed in certain management frames like probe requests and association requests.

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

DHCP Option 43 is utilized to provide vendor-specific information to DHCP clients. In WLAN deployments, particularly with lightweight access points (APs), Option 43 is used to convey the IP address of the Wireless LAN Controller (WLC) that the AP should join. The AP includes a Vendor Class Identifier (Option 60) in its DHCP Discover message, and the DHCP server responds with Option 43 containing the WLC's IP address. This mechanism facilitates the automatic discovery and association of APs with their respective controllers, streamlining network deployment and management.Cisco

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."

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.

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:

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.

Comprehensive and Detailed Explanation:

When analyzing a customer's existing infrastructure, obtaining read-only access to certain systems is crucial for gathering information without risking unintended changes. The systems include:

B. RADIUS:Accessing RADIUS servers allows you to review authentication logs and configurations, helping to understand how network access is managed.

C. Switches:Reviewing switch configurations and logs provides insights into network topology, VLAN assignments, and potential bottlenecks.

D. Active Directory:Access to Active Directory helps in understanding user authentication mechanisms, group policies, and organizational units, which are essential for designing access controls.

E. Routers:Examining router configurations and routing tables aids in understanding traffic flow, subnetting, and inter-network connectivity.

A. Clients:Direct access to client devices is generally unnecessary and can pose privacy concerns. Information about client behavior can often be gathered through network monitoring tools.

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.

Orthogonal Frequency Division Multiple Access (OFDMA), introduced in 802.11ax, enhances efficiency by dividing a channel into smaller sub-channels called Resource Units (RUs). This allows multiple devices to transmit simultaneously within the same channel bandwidth, reducing latency and improving throughput. Unlike previous standards like 802.11n and 802.11ac, which primarily support single-user transmissions per channel, OFDMA's ability to handle multiple concurrent transmissions without relying on MU-MIMO leads to more efficient spectrum utilization and better performance in dense environments.

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.

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.

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."

In stadium environments where aesthetics are important, using under-seat enclosures for APs is a common practice. These enclosures conceal the APs, protect them from physical damage, and maintain the manufacturer's warranty, as they do not require modifications like painting or unauthorized mounting methods.

Comprehensive and Detailed Explanation:

Multicasting is a network capability that allows a single data stream to be transmitted to multiple recipients simultaneously, which is highly efficient for live video streaming applications. By configuring multicasting in WLAN implementations, bandwidth usage is optimized, and network congestion is reduced, as the same data does not need to be sent individually to each client. Implementing multicast support ensures that all intended recipients receive the video stream with minimal latency and resource utilization.

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:

In the context of WLAN design, certain enterprise verticals have distinct requirements and considerations:

A. Education:Educational institutions often require robust WLANs to support high-density environments, BYOD policies, and seamless roaming across campuses.

C. Healthcare:Healthcare facilities demand WLANs that support critical applications, real-time data access, and stringent security protocols to protect sensitive patient information.

E. Retail:Retail environments utilize WLANs for point-of-sale systems, inventory management, and customer engagement through Wi-Fi services.

B. WarehousesandD. Office environmentsare also important but are not typically categorized among the top three enterprise verticals in WLAN design considerations.

Comprehensive and Detailed Explanation:

While SSID hiding might seem like a security measure, it's not effective because certain management frames must include the SSID, making it discoverable. Specifically, theAssociation Requestframe always includes the SSID. This frame is sent by a client device when it attempts to associate with an access point (AP), and it must specify the SSID to identify the desired network. Therefore, even if the SSID is hidden in beacon frames, it can still be detected through association requests.

Beacon frames: Typically used by APs to advertise their presence; can be configured to omit the SSID.

Probe request/response frames: Used during active scanning; the SSID may or may not be included.

Authentication response frames: Do not necessarily include the SSID.

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 leverage the advanced features of 802.11ac, such as wider channel bandwidths, higher modulation schemes, and increased spatial streams.

The CWDP-305 Official Study and Reference Guide emphasizes the importance of considering client capabilities during WLAN upgrades:

"When upgrading a WLAN, it's essential to assess both infrastructure and client devices. Upgrading APs without corresponding client support may not yield the expected performance improvements."

Therefore, in this scenario, the most likely cause of the unchanged throughput is that the client devices were not upgraded to support 802.11ac.

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.

Co-Channel Interference (CCI) occurs when multiple APs on the same channel are heard in the same area, even at relatively low signal levels. CCI is not eliminated simply because signals are below −75 dBm. In fact, CCI is a concern even when APs are heard at levels as low as −85 dBm or lower.

From CWDP-305:

“CCI can be problematic even when the signal from neighboring APs is heard at levels between −85 dBm to −93 dBm. Effective channel planning requires minimizing overlap of same-channel signals at or above these thresholds.”

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

Software-defined radios (SDRs) offer flexibility in RF operation. In dual-band APs, an SDR can be programmed to operate on either 2.4 GHz or 5 GHz, allowing dynamic optimization of the spectrum based on demand and interference.

From CWDP-305:

“Software-defined radios can be configured to operate in either band, allowing administrators to shift coverage based on band congestion or capacity requirements.”

This flexibility helps address issues in high-density deployments or when minimizing interference is critical.

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

Comprehensive and Detailed Explanation:

WPA/WPA2-Personal is typically used in scenarios where:

A.Client devices lack support for 802.1X/EAP, making enterprise authentication methods unfeasible.

C.Devices are provisioned in bulk with shared credentials, simplifying deployment without the complexity of individual 802.1X configurations.

However:

B.High-latency roaming is undesirable; low-latency is preferred for seamless connectivity.

D.Requiring unique access credentials aligns more with WPA/WPA2-Enterprise, which supports individual authentication.

In a Single Channel Architecture (SCA), all access points (APs) operate on the same channel and share a virtual Basic Service Set Identifier (BSSID).The wireless controller manages client associations by directing the client to the AP with the strongest Received Signal Strength Indicator (RSSI), ensuring optimal connectivity.

The CWDP-305 Official Study and Reference Guide explains:

"Using a SCA means that all APs will be using the same channel in a given layer. How is the AP with which the client associates determined? C. All APs share a virtual BSSID. A controller will tell the closest AP to the client to communicate with it, since it has a greater RSSI from the client."

Comprehensive and Detailed Explanation:

Co-Channel Interference (CCI) in the 2.4 GHz band can significantly degrade WLAN performance due to the limited number of non-overlapping channels available.If the WLAN was primarily designed for 5 GHz, the 2.4 GHz band serves as a secondary or best-effort option.In such cases, turning off 2.4 GHz radios on some APs can reduce CCI by minimizing overlapping coverage areas, thereby improving overall network performance.

In Europe, the 2.4 GHz band includes channels 1 through 13, whereas in North America, channels 12 and 13 are typically not used due to regulatory restrictions.If the AP in the hotel room is operating on channel 13, a laptop configured for North American standards may not detect or connect effectively to that channel, resulting in a low Received Signal Strength Indicator (RSSI).

The CWDP-305 Official Study and Reference Guide explains:

"Client devices configured for specific regulatory domains may not support all channels available in other regions. This can lead to connectivity issues when devices encounter channels that are not permitted in their configured domain."

Therefore, the most likely cause of the low RSSI is the client's inability to properly connect to the AP operating on channel 13, leading it to associate with a more distant AP on a different channel, hence the weaker signal.

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.

Comprehensive and Detailed Explanation:

Per-user Pre-Shared Keys (PSKs) offer several advantages over a single PSK used across an entire Extended Service Set (ESS):

User-Based Access Control:Assigning unique PSKs to individual users allows for better tracking and control over network access.

Simplified Key Management:If a user's PSK is compromised or they leave the organization, only their key needs to be changed, not the entire network's.

Option C:Per-user PSKs are not a standard defined or certified by the Wi-Fi Alliance; they are an implementation choice.

Option D:Mutual authentication is a feature of WPA/WPA2-Enterprise using 802.1X, not of PSK-based systems.

Effective Isotropic Radiated Power (EIRP) is calculated by adding the transmit power (in dBm) to the antenna gain (in dBi).

Transmit power: 25 mW = 14 dBm

Antenna gain: 3 dBi

EIRP = 14 dBm + 3 dBi = 17 dBm

The CWDP-305 Official Study and Reference Guide provides guidance on calculating EIRP to ensure compliance with regulatory limits and optimal network performance:

"EIRP is the sum of the transmitter output power and the antenna gain, accounting for any losses. Accurate EIRP calculations are essential for regulatory compliance and effective wireless design."

Comprehensive and Detailed Explanation:

An incorrect Frame Check Sequence (FCS) indicates that the frame was corrupted during transmission. This corruption can be due to various factors, but in the context of a WLAN, common causes include multipath interference and excessive collisions. Multipath occurs when RF signals reflect off surfaces and arrive at the receiver at different times, causing interference. Excessive collisions can happen in environments with high device density or overlapping coverage areas, leading to degraded performance.

The Bill of Materials (BoM) is a comprehensive list that details all the components, devices, and parts required for the deployment of a WLAN infrastructure.It serves as a critical document for procurement and ensures that all necessary items are accounted for before the deployment begins.

The CWDP-305 Official Study and Reference Guide emphasizes the importance of the BoM in the design and deployment process:

"Create, distribute, and communicate design documentation - Bill of Materials (BoM)"NWExam

Comprehensive and Detailed Explanation:

The Duty Cycle view in a spectrum analyzer indicates the percentage of time a frequency is occupied by RF transmissions. By analyzing the duty cycle, you can assess whether a channel is too congested for additional AP deployment. A high duty cycle suggests that the channel is frequently used, which could lead to increased contention and degraded performance if another AP is added.

CAPWAP (Control and Provisioning of Wireless Access Points):Modern standard protocol for tunneling management and data frames between APs and WLCs.

GRE (Generic Routing Encapsulation):Sometimes used by vendors as an alternative tunneling method, especially for data transport.

From CWDP-305:

“CAPWAP is the most widely used protocol for communication between access points and controllers. GRE is also utilized in some vendor implementations for tunneling user data.”

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

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

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."

In the context of evaluating published competitive tests by equipment vendors, it's crucial to recognize the common omissions that can impact the validity and applicability of the test results.

According to the CWDP-305 Official Study and Reference Guide, these tests often lack:

Client devices and configurations: The specific client devices used in testing, along with their configurations, are frequently not disclosed. This omission makes it challenging to assess the compatibility and performance implications for different client types.

Detailed test methodology: A comprehensive description of the test procedures, including the environment, tools used, and step-by-step processes, is often missing. Without this information, replicating the tests or understanding the context of the results becomes difficult.

Detailed configurations of each vendor’s equipment: The exact settings and configurations applied to the equipment under test are typically not provided. This lack of transparency hinders the ability to determine whether the equipment was optimized or configured in a standard manner during testing.

These omissions can lead to biased or non-reproducible results, making it essential for network professionals to critically assess such vendor-published tests.

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.

In public WLAN environments, security and privacy are paramount. To prevent clients from communicating directly with each other, many WLANs implement peer-to-peer blocking (also known as client isolation). This feature ensures that each client can communicate with the internet but not with other clients on the same network, thereby enhancing security.

The CWDP-305 Official Study and Reference Guide discusses this feature:

"Client isolation prevents wireless clients from communicating directly with each other, which is especially important in public or guest networks to protect user privacy and security."

Therefore, the inability to detect other devices on the subnet is likely due to peer-to-peer blocking being enabled on the WLAN infrastructure.

EAP-TLS (Extensible Authentication Protocol-Transport Layer Security) is considered one of the most secure EAP methods. It requires both the client and the server to have certificates, enabling mutual authentication. This method eliminates the need for passwords, reducing the risk of credential theft.

EAP-TTLS allows for server-side certificates and can use passwords for client authentication, making it less secure than EAP-TLS.

PEAP encapsulates EAP within a TLS tunnel, typically using server certificates and password-based client authentication.

Comprehensive and Detailed Explanation:

In 802.1X/EAP authentication, the authenticator (typically the AP or controller) communicates with the RADIUS server using a shared secret for mutual authentication.If this shared secret is misconfigured or does not match on both ends, the RADIUS server will reject authentication requests, leading to client association failures.Therefore, verifying that the shared secret is correctly configured and matches on both the authenticator and the RADIUS server is a critical troubleshooting step.Techimike

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.

Comprehensive and Detailed Explanation:

For enterprises requiring high network uptime, it's crucial to design for redundancy and failover in both the wireless and wired components of the network. This includes:

Wireless and Wired Network Failover:Ensuring that both wireless access points and wired infrastructure have redundancy to prevent single points of failure.

Physical Aspects (Power and Cabling):Implementing redundant power supplies, uninterruptible power supplies (UPS), and proper cabling practices to maintain network availability during power outages or hardware failures.

Conducting a site survey in environments such as heavy machinery repair facilities involves potential hazards, including moving equipment, loud noises, and other safety risks.Therefore, wearing Personal Protective Equipment (PPE) is essential to ensure the safety of the surveyor.

The CWDP-305 Official Study and Reference Guide advises:

"When performing site surveys in industrial or hazardous environments, always adhere to safety protocols, including the use of appropriate Personal Protective Equipment (PPE) such as hard hats, safety glasses, and steel-toed boots."

This ensures that the survey is conducted safely and complies with occupational health and safety regulations.

802.1X/EAP preauthentication allows a client to authenticate with a new AP before roaming, reducing handoff latency. However, preauthentication typically requires that the new AP is within the same Layer 2 domain as the current AP. If the new BSS operates on a different IP subnet (Layer 3 domain), the STA may not attempt preauthentication due to the inability to establish a direct Layer 2 connection for the EAP exchange.

Comprehensive and Detailed Explanation:

Short ASCII passphrases, especially those 12 characters or fewer, are more vulnerable to dictionary attacks. Attackers can use precomputed tables or brute-force methods to guess these passphrases, especially if they are common or simple. The WPA/WPA2-Personal security model relies on the strength of the passphrase; thus, longer and more complex passphrases significantly enhance security.

Option B:The strength of group keys in a BSS is not directly affected by the length of the passphrase but rather by the encryption protocols in use.

Option C:Regardless of the passphrase length, the Pairwise Master Key (PMK) derived is 256 bits.

Option D:Most AP and client vendors support ASCII-based passphrase entry, making this option incorrect.

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