CWDP-304

Certified Wireless Design Professional

CWDP® – Certified Wireless Design Professional

CWDP – 304

1 / 60

Receiver sensitivity is related to what other radio performance measurements?

Antenna gain

Noise figure

Spectral regrowth

Amplifier compression

2 / 60

Your customer requires fast secure roaming. Which two types of roaming are specified in 802.11-2016 FT roaming that will help meet this goal?

FT and OKC

Over-the-Air and Over-the-Wire

Over-the-Air and Over-the-DS

FT and TKIP

3 / 60

Why is EAP-MD5 not used as an acceptable EAP type?
(Choose all that apply.)

It does not support mutual authentication.

Its authentication exchange is subject to dictionary attacks.

It requires use of the weak RC5 encryption algorithm.

It does not export dynamic keys.

It does not support secure encryption protocols.

4 / 60

What are some significant drawbacks that are present with WPA/WPA2-Enterprise that are not present with WPA/WPA2-Personal?
(Choose all that apply.)

WPA/WPA2-Enterprise always requires X.509 certificates for server authentication.

WPA/WPA2-Enterprise does not provide a way to perform per-user authorization and access control.

WPA/WPA2-Enterprise does not support the use of usernames/passwords for client authentication.

WPA/WPA2-Enterprise often requires additional backend infrastructure components that are not required with WPA/WPA2-Personal.

WPA/WPA2-Enterprise often requires more administrative overhead for configuration than WPA/WPA2-Personal.

5 / 60

What is another name for an AAA client?

User database

Network access server (NAS)

RADIUS server

Authentication server

Supplicant

6 / 60

An engineering firm just upgraded their WLAN form nine 802.11n APS to nine 802.11ac APs. After this upgrade, they did not see any improvement in throughput. What is the most likely cause of this result?

APs are transmitting at a low transmit power

APs are mounted on the wall

The APs are still using the 5 GHz lower band

The clients were not upgraded

7 / 60

A table of VLANs in a _________ document should include what device performs ________ services.
(Fill in the blanks)

LLD, bridging

HLD, QoS

LLD, routing

HLD, routing

8 / 60

DAS design is largely based on, and most effective for, what antenna technology?

MISO

SISO

SIMO

MIMO

9 / 60

Prior to meeting with the customer for the first time, you should do which of the following?

Research the customer as much as possible. Try to understand what their business is, who their customers are, and any other information you can find regarding product lines and recent press announcements.

Decide which vendor they will benefit most from.

Find out what vendor their competitors use.

Plan an initial design to present to them.

10 / 60

What basic RF math formula should be used as a baseline to convert an RF value in units of dBm into a value of mW?
*Note: dBm in the formulas represents the known dBm value

0 dBm = 3 mW

0 dBm = 4 mW

0 dBm = 2 mW

0 dBm = 1 mW

11 / 60

An acceptable use policy will result in what benefit for the provider?
(Choose all that apply.)

Attempts to protect the organization from users performing illegal actions

Requires users to adhere to the laws dictated by the provider while using the network

Provides a contract that users must accept that governs their use of the network

Attempts to protect the organization from data loss to the guest user device while using the guest network

12 / 60

The thermal noise is at −174 dBm/Hz. A spectrum analyzer has a resolution bandwidth of 1 kHz and a 5 dB noise figure. What is the level of the noise floor?

−139 dBm

−204 dBm

−174 dBm

−144 dBm

13 / 60

What statements are true of PEAPv0/EAP-MSCHAPv2?
(Choose all that apply.)

Allows X.509 client certificates

Has relatively high management overhead compared with other EAP types

Protects the supplicants actual username inside a TLS tunnel

Is widely supported by client supplicants

Specifies three EAP phases: Phase 1, Phase 2, and Phase 3

Has a tunneled and an untunneled mode

14 / 60

Modulation can be defined as:

The process of incorporating a chipping code to build resilience

The process of representing data using RF coding techniques

The process of modifying a carrier signal to represent data

The process of encoding data symbols using a carrier frequency

15 / 60

What are some of the common ways by which WLAN users receive network permissions?
(Choose all that apply.)

RADIUS return attributes

WLAN infrastructure group profiles

LDAP database WLAN plug-ins

WLAN profile settings

16 / 60

Your new customer is concerned about maintaining privacy for their proprietary information when you conduct information gathering for their WLAN design. Which document can you use to directly address their concern?

Hold Harmless

SoW

BoM

NDA

17 / 60

If the amplifier in Question 4 has a noise figure of 10 dB but a gain of 0 dB, what is the total noise figure of the cable, amplifier, and filter in series?

10 dB

70 dB

16 dB

75 dB

18 / 60

When viewing channel utilization information from a protocol analyzer, if high channel utilization is occurring, what should you ensure does not exist?

High levels of workload

High frames per second

An RF signal generator causing an RF DoS

A high percentage of low PHY rates

19 / 60

What type of protection should be provided to outdoor antenna installations?

Brownouts

Static electricity

Lightning surge suppression

A/C spikes

20 / 60

A wireless engineer from your company performed a site survey in an office building where a wireless network extension was needed.

He reports that while performing a Layer 1 sweep near a meeting room full of people, he detected RF activity with a very low duty cycle. He is unsure how to interpret what he recorded to determine its impact on a future Wi-Fi network.

What is true about this RF environment and its potential impact on the WLAN?

The signal affects the entire spectrum and will render the wireless network unusable. It must be located and removed.

The signal is typical of a high radio card background noise. It shows that the card used for the Layer 1 sweep should be replaced and the Layer 1 sweep re-done.

The signal has a low duty cycle and should not be of major impact on the wireless network.

The signal is alternating between peaks (high interference level) and valleys (low interference level). The network channel design must be built to avoid the affected peak frequencies.

21 / 60

For what types of systems should you request read-only access to in order to perform an analysis of the customer’s existing infrastructure?
(Choose all that apply.)

RADIUS

Active Directory

Switches

Routers

Clients

22 / 60

After designing a WLAN infrastructure using predictive design software. What’s the best way to validate the predictive design in the physical space before deployment, if time and budget allow for it?

Deploy all of the APs as they’re shown in the predictive design and perform a passive site survey.

Perform an AP-on-a-Stick survey using AP locations based upon the predictive design to confirm each AP’s placement.

Deploy all of the APs as they’re shown in the predictive design and perform an active site survey.

Use a client device positioned where the APs will be installed and measure the signal from the client device

23 / 60

ABC Company has a WLAN controller with 10 controller-based APs; the Voice SSID is configured for centralized data forwarding. Each AP is connected to an access port on a layer-2 Ethernet switch. Each layer-2 switch is uplinked to a single layer-3 core Ethernet switch.

The WLAN controller is connected directly to the layer-3 core Ethernet switch. Layer-3 tunnels are created between all controller-based APs and the WLAN controller. A voice server is connected to the layer-3 Ethernet switch.

When a voice-enabled QoS STA sends an IP data packet to a voice server in this scenario, the DSCP value carried in the STA’s IP data packet gets mapped to what and by which device?

The DSCP value is mapped to an IEEE 802.1Q VLAN tag by the access point.

The DSCP value is mapped to the DSCP value in the encapsulating IP header by the layer-3 switch.

The DSCP value is mapped to an IEEE 802.1Q priority tag value by the WLAN controller.

The DSCP value is mapped to an IEEE 802.1p (802.1D-2004) UP value by the access point.

24 / 60

A controller-based WLAN infrastructure has its controller on a different subnet than its APs. What device must be used to enable any communication between the Controller and the APs?

Router

Wireless bridge

NTP server

PoE Layer 2 switch

25 / 60

Your customer’s 802.11n laptops are not able to see the SSID in the 5 GHz band in the conference room. When doing a walkthrough using one of these laptops, you confirm that it is unable to see the SSID in the 5 GHz band in the conference room.

When using your own 802.11 ac laptop, you’re able to see the SSID. What is the most likely cause of this problem?

Their laptops are SISO clients

The AP is configured to use channel 36

The AP is on channel 144

The customer laptop does not support Transmit Beamforming

26 / 60

A signal passes through a 10-meter cable, an amplifier, and then a filter. The amplifier has an output that is eight times higher in power than its input. Each meter of cable reduces the signal level by a factor of 4. The filter has a loss of 5 dB.

What is the total loss/gain of the three elements in series?

65 dB loss

56 dB loss

37 dB loss

16 dB gain

27 / 60

When performing a capacity planning analysis on a LAN with a large number of access switches and distribution blocks, what can you check to see if existing links have too much congestion?
(Choose all that apply.)

Interface stats

Access switch VLAN uplinks

VLAN stats

Uplinks from distribution to core layer

28 / 60

You are performing a walkthrough for a PTP wireless survey. You will need to use a small communication tower to install the link. How should you plan to perform the survey?

Install the radio and equipment and tune later.

Temporarily install the equipment to the radio tower.

Use a lighting tripod.

Use a man-lift.

29 / 60

Given: In a site survey deliverable report, you are expected to explain the spectrum measurements taken at the customer’s site.

What portion of a spectrum analyzer view can be used to determine if a given channel is too active for use as the active channel for a new AP?

Frame decode

Duty cycle

Real time FFT

Device list

30 / 60

In an outdoor 802.11n deployment, a receiver is getting strong signals that are a direct line and signals that are have bounced off buildings that are a couple blocks away.

What parameter in the radio should be adjusted to ensure proper communications?

Channel bandwidth

MRC

Modulation

GI

31 / 60

Which EAP type does the supplicant send to request a different EAP type?

Reject

NAK

Logoff

EAPOL Start

32 / 60

A receiver includes a cable connected to the antenna, a filter, an LNA, and a cable, in that order.

The cable connected to the antenna has a loss of 3 dB, the filter loss is 1 dB, the noise figure of an LNA is 4 dB, and the cable connected to the rest of the receiver has a 5 dB loss. The gain of the LNA is 20 dB.

What is the overall noise figure of the receiver?

24 dB

8 dB

13 dB

4 dB

33 / 60

You are on site, planning a network at a freight shipping company on a busy harbor. Since the preliminary WLAN design specifies support for the 5 GHz spectrum, you would like to test for radar pulses to determine if DFS channels should be supported at this facility.

As a part of your spectral survey with a laptop-based analyzer, you include DFS testing to identify the presence of radar. This is done by manually observing Real-time FFT, Duty Cycle, and Active Devices charts of the spectrum analyzer software.

What potential drawback is present with this DFS test method?

Manual identification of radar pulses using spectrum analysis charts can be very difficult due to radar’s low amplitude at the Wi-Fi receiver.

Modern spectrum analyzer adapters do not provide the necessary bandwidth resolution required to detect and measure radar signatures.

Many WLAN products that support DFS channels report several false positives. Ideally, the actual WLAN equipment used in the deploymentshould be used to test for DFS.

Some sources of 5 GHz radar, such as military ships, are mobile in nature. A longer, automated test setup should be used to identify the presence or absence of radar.

34 / 60

Which of the following are examples of Wi-Fi interference for channel 6? Assume all access points are within RF range of one another.
(Choose all that apply.)

Other access points that are not on your network but are on channel 3

Other access points that are on your network but are on channel 1

Other access points on your network that are on channel 6

Other access points that are not on your network but are on channel 11

35 / 60

An associated STA detects a new BSS with the same SSID as the STA’s current BSS. The new BSS uses a different IP subnet than the current BSS. If the STA is configured to use 802.1X/EAP preauthentication, what is likely to occur?

The STA will attempt to preauthenticate, but fail because the new BSS uses a different data-link broadcast domain.

The STA will attempt to preauthenticate and succeed if DHCP is supported on the new subnet.

The STA will not attempt to preauthenticate because the new BSS uses a different IP subnet.

The STA will attempt to preauthenticate and succeed if IP Mobility is enabled on the AP or WLAN controller.

36 / 60

Lace Doily Company is highly concerned about aesthetics and you are being asked to keep APs from being visible on the ceiling. What best practice option should you explore as a first step?

Paint the APs or antennas using the same paint used for walls or ceilings.

Investigate using small external antennas that can be mounted to the ceiling and walls.

Install APs with internal antennas above the ceiling.

Point out that there are smoke detectors, sprinklers, lighting fixtures, speakers, and other existing items and the APs will hardly be noticed.

37 / 60

In the enterprise, when is WPA/WPA2-Personal generally a recommended solution?
(Choose all that apply.)

When client devices do not support 802.1X/EAP

When mobile device applications require high-latency roaming times between APs

When the network security policy demands that each user have unique access credentials

When client devices are provisioned in bulk and would otherwise share 802.1X credentials

38 / 60

You are analyzing a WLAN/wired LAN implementation. You notice that DHCP option 82 is in use. What does this indicate?

DHCP relay

DHCP denial of access

WLC IP address

NTP IP address

39 / 60

Using a free space model, if the frequency is doubled, the loss is increased by how much?

27.55 dB

6 dB

3 dB

Unchanged

40 / 60

Location technology (RTLS) can use which of the following methods?
(Choose all that apply.)

Passive RFID

UHV

Active RFID

Infrared

UWB

802.11-capable laptops

Sound

41 / 60

When doing some frame capturing over the air during a voice call, you realized that frames on the downlink (from the AP to the client) direction are not being transmitted with the correct UP value for voice frames, but on the uplink (from the client to the AP) direction are being transmitted correctly.

What’s the cause of this issue?

Bad client driver

AP is not receiving enough PoE, thus not using QoS features

Somewhere on the wired network QoS markings aren’t being trusted

Faulty antenna on the AP

42 / 60

Why does a frame transmitted at 1 Mbps have a greater usable range than the same frame transmitted at 54 Mbps?

Lower data rate RF transmissions travel at higher speeds and are less likely to experience collisions.

Free space path loss causes greater signal dispersion for higher rate transmissions.

To improve reliability, 802.11 STAs increase transmit power as the signaling rate decreases.

Receiver sensitivity requirements are lower for frames transmitted with less complex modulation and coding.

43 / 60

In general, when planning for a multi-floor installation, how should the APs be installed on each floor in relation to their locations?
Choose the single best answer.

Avoid installing APs directly above one another to avoid CCI and ACI.

Install APs directly above one another to better control CCI and ACI

Install only omni-directional antennas to completely avoid ACI.

Install only semi-directional antennas to completely avoid CCI.

44 / 60

Video applications running over a laptop computer will likely not support which of the following?

TSPECs

A-MPDU

Transmit timing control

WMM Power Save

Fragmentation

802.1X/EAP

45 / 60

You run across an area in your walkthrough where decorative ceilings are installed. The customer has asked to use ceiling mounted APs with omnidirectional antennas only. What should you recommend?

Install the AP on the wall.

Install a bracket on a wall to mount the AP.

Install the AP above the ceiling.

Recommend a different AP designed for wall mounting.

46 / 60

Active surveys benefit from what additional information versus a passive scan?
(Choose all that apply.)

PHY rates

Loss

Retries

Signal to noise

RSSI

47 / 60

The project sponsor will always be able to answer what type of question about the project?

Regulatory or legal requirements

The hardware vendor that will be deployed

The type of security model to use

The client adapters that should be used given the environment

Which business objectives must be met

48 / 60

What parallel term in RF terminology can be used to compare to a broadcast domain with Ethernet networks?

Channel reuse

Spectrum load balancing

Contention domain

RRM arbitration

49 / 60

During lunch time in the break room of a company, Wi-Fi connectivity on the 2.4 GHz band is intermittent. Every other time of the day, it works fine. What’s the likely cause of this issue?

Toasters and ovens are heating up the air, raising the noise floor with the Wi-Fi on the 2.4 Ghz band

Microwaves in the cafeteria are interfering with the Wi-Fi on the 2.4 GHz band

Employees are using their cell data instead of using the Wi-Fi

The AP in the cafeteria keeps rebooting due to lack of PoE budget on the switch

50 / 60

Assume that your network operates in a regulatory domain that allows use of the entire 5 GHz space allowed in the 802.11ac amendment. In your upcoming 802.11ac deployment, you would like to take advantage of the performance improvements that result from channel bonding.

However, after extensive testing, you have determined that your mission-critical WLAN should not use channels requiring DFS support.

Given those two criteria (enable channel bonding and disable DFS channels), in the 5 GHz spectrum, how many non-overlapping 40 MHz channels will your system be able to use?

2

6

3

4

51 / 60

Which one of the following is the most effective way to determine if radar will force APs away from DFS channels?

Use a protocol analyzer looking for radar.

Use a spectrum analyzer looking for radar.

View the AP logs looking for DFS events.

View the wired router logs looking for DFS events.

52 / 60

By operating on a single-channel design and using a single BSSID, what does an SCA eliminate?

Management frame poisoning

Client roaming decisions

Spectrum load balancing

Contention domain

53 / 60

Your company is located in a downtown high-rise building. You’ve configured your network so that your lowest mandatory rate is 12 Mbps. Users are complaining about poor throughput.

Upon inspection, you notice that over 90 percent of the traffic is being sent at 1 Mbps. What is most likely the cause?

A software bug on the network

An AP that has lost its connection to its controller and is repeatedly sending management frames

Neighboring networks from above and/or below that are very busy and have the lower data rates enabled

Nothing, since this is normal

54 / 60

When installing APs on high ceilings, what should be the most common PPE to be used?

Clean suits, gloves and jacket

Hardhat, high visibility vest and body belt

Clean suits, masks and glasses

Glasses, gloves and jacket

55 / 60

Why should band steering algorithms allow stations to connect to the 2.4 GHz band after some number of ignored Probe Requests?

Because the 802.11 standard requires it.

Because some clients are persistent clients that will not move on to the 5 GHz band.

Because the AP will experience a buffer overflow if they do not eventually respond with a Probe Response.

Because the FCC requires it.

56 / 60

What contributing factor might cause two different types of clients to perform differently at the same location and at the edge of coverage?

AP transmit power

Fragmentation threshold

Noise floor

Client receive sensitivity

AP receive sensitivity

57 / 60

What is the minimum PoE budget needed on a switch to support 6 (six) APs that can only be powered using IEEE 802.3at if no other details are provided?

320 W

240 W

60 W

180 W

58 / 60

Aesthetics are very important in some environments. What common installation technique can be used to best meet this requirement in a stadium?

Mounting on a non-fixed pole

Mounting on the walls

Using enclosures under the seats or on hand-rails

Painting to match team colors

59 / 60

When live video streaming solutions that transmit simultaneously to more than one recipient are used, what special capability should be considered and configured in all affected WLAN implementations?

Secure TCP

IPSec

IPv6

Multicasting

60 / 60

As a general design practice, what minimum PHY rate is recommended to ensure VOWLAN quality?

36 Mbps

24 Mbps

18 Mbps

54 Mbps

11 Mbps

Your score is

The average score is 76%

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