2.3 Given a scenario, select and configure wireless devices and technologies. Flashcards
(20 cards)
The office received only one wireless access point (AP) to set up its network. The network engineers need to work with this device while more are in route. In addition, the AP must try to support all office works as possible.
How should the network engineers set up the AP so most employees can connect to it? (Select two.)
Mount AP in the ceiling
Configure maximum power output
A new office room on the second floor needs wireless networking installed to support video conferencing equipment. The IT manager has set aside a small budget, but the network engineer needs to support at least two 2,167 Mbps streams over 80 MHz 5 GHz band channels.
While staying within budget, what minimum 802.11 wireless standard access point (AP) can the engineer purchase to complete the work?
Wi-Fi 4
Wi-Fi 5
Wireless g
Wi-Fi 6
Wi-Fi 5
Wi-Fi 5 (802.11ac) is designed to provide network throughput similar to Gigabit Ethernet. An AC5300 can support 1000 Mbps over a 40 MHz 2.4 GHz band channel and two 2,167 Mbps streams over 80 MHz 5 GHz band channels.
Wi-Fi 4 (802.11n) is rated at providing 72 Mbps per stream. Assuming the maximum number of four spatial streams and optimum conditions, the nominal data rate could be as high as 600 Mbps for a 40 MHz bonded channel.
Wi-Fi 6 (802.11ax) is designed to approximate 10G connections such as the AX11000. This is achievable using a 6 Ghz frequency band.
Wireless g or 802.11g uses the 2.4 GHz frequency band and has a nominal data rate of 54 Mbps.
What is a type of network device used for improving wireless signal strength within homes and small offices called?
Wireless range extender
Which of the following terms relates to the bending of radio waves?
- Attenuation
- Reflection
- Refraction
- Absorption
- Refraction
Glass or water can cause radio waves to bend and take a different path to a receiver and cause the data rate to drop. This is known as refraction.
Mirrors or shiny surfaces cause signals to reflect, meaning that a variable delay is introduced. Refection causes packets to be lost and consequently the data rate to drop.
Absorption refers to the degree to which walls and windows will reduce signal strength (some of the radio wave’s energy is lost as heat when passing through construction materials).
Attenuation is the loss of signal strength that occurs as the signal travels through the media. Some media is more prone to attenuation than others.
A new office building was constructed right outside a United States military. The building has a few wireless access points (APs) that must adhere to some federal regulations because of the building’s locations.
What regulation would the building management have to adhere to regarding these APs?
- Decrease the power output
Decreasing the power output reduces the AP frequency range. This can prevent the food market Wi-Fi frequency from going over to the military base where wireless signals are commonly restricted.
In America, regulations permit channels 1-11 only, while in Europe, regulations permit channels 1-13, and in Japan, regulations allow all 14 channels.
Using the maximum power output will provide the widest frequency range for an AP. This may cause the frequency to go over to the military base, which may be illegal in some countries.
Effective Isotropic Radiated Power (EIRP) is the sum of transmit power, antenna cable/connector loss, and antenna gain. EIRP must not exceed regulatory limits.
In terms of radio wave signals, which term describes the impact of thick walls and ceilings
Which cellular technology provides an estimated real-world download of up to 300 Megabits per second (Mbps)?
- 2G
- 3G
- 4G
- 5G
- 5G
5G real-world speeds range from about 50 Mbps to 300 Mbps currently. 5G uses different spectrum bands from low (sub-6 GHz) to medium/high (20-60 GHz).
4G or Long Term Evolution (LTE) is theorized to have a maximum download speed of 150 Mbps but currently performs real-world at around 20 Mbps.
3G is also known as CDMA2000/Evolution-Data Optimized (EV-DO). CDMA network providers use this, which can support a 3.1 Mbps downlink and 1.8 Mbps uplink.
2G cellular data service was capable of around 14.4 Kbps. 2G was made available with two formats during its inception: Global System for Mobile Communication (GSM)-based phones and TIA/EIA IS-95 (cdmaOne)-based handsets.
An engineer troubleshoots a wireless access point which is not functioning as expected. The engineer learns that the configuration is set for bridged mode to cabled segments.
Based on the configuration type, which of the following describes the access point’s configuration limitation?
- In bridged mode, access point functionality does not support wireless clients
A wireless distribution system (WDS) can bridge two separate cabled segments. When WDS is in bridge mode, the access points (AP) will not support wireless clients.
Wireless networks expand using devices called wireless range extenders (WREs), which are lightweight APs functioning in repeater mode only.
A wireless LAN controller is a hardware device or software application which can be run on a server or workstation to centralize the management function of a wireless network.
A wireless distribution system (WDS) can be configured via multiple access points to cover a larger area. As with configuring extenders, the access points (AP) must be set to use the same parameters.
A computer has difficulty connecting to a wireless access point. What common wireless properties does a user need knowledge of to properly access a Wi-Fi network? (Select two.)
SSID
Passphrase
The manager would like to set up a temporary wireless network to connect a computer to the corporate office’s network to show a presentation slide and video only accessible from the internal SharePoint. The device will only support a pre-shared key (PSK) authentication process.
Which wireless network feature will provide the latest security that will not require integrating services with a local Active Directory (AD)?
WPA2 - Personal
A network consultant calculates the sum of the transmit power, antenna cable/connection loss, and antenna gain.
What is the consultant trying to calculate?
- Channel Utilization
- Captive Port
- Effective isotropic radiated power (EIRP)
- Received Signal Strength Indicator (RSSI)
Effective isotropic radiated power
The power at which an access point transmits is configurable. Effective Isotropic Radiated Power (EIRP) is calculated as the sum of transmit power, antenna cable/connector loss, and antenna gain.
The Received Signal Strength Indicator (RSSI) is the strength of the signal from the transmitter at the client end.
Most captive portal issues arise because the redirect does not work. The captive portal should use HTTPS.
Channel utilization can be measured from the access point or using a Wi-Fi analyzer. As a design goal, a channel should exhibit no more than 50% utilization.
Users at a medium-sized business utilize an ad hoc approach when connecting wireless devices.
Which of the following applies to an ad hoc topology?
- It is grouped into an extended service set (ESS)
- It uses an independent basic service set (IBSS)
- It uses a basic service set (BSS)
- It is able to roam in an extended service area (ESA)
- IBSS
An independent basic service set (IBSS) is an ad hoc topology where the wireless adapter allows connections to and from other wireless devices.
Clients can roam within an extended service area (ESA). ESA uses multiple access points (APs) with the same service set identification (SSID) and security configuration connected by a wired network.
An extended service set (ESS) uses more than one basic service set to create.
A basic service set (BSS) is an AP that mediates communications between client devices and provides a bridge to a cabled network segment.
A farmer wants to install multiple antennas on the farm to boost radio communication across long distances. The antennas should be easy to install and require minimum maintenance and up-front costs.
What type of antenna would BEST meet the farmer’s requirements?
- Parabolic Grid Antenna
- Torus antenna
- Yagi antenna
- Static dish antenna
- Yagi Antenna
A Yagi (a bar with fins) antenna is a unidirectional signal that is useful for point-to-point wireless bridge connections. This is common for outdoor use and can boost radio signals across long distances.
A static dish antenna is a parabolic or dome shaped antenna that is unidirectional. This antenna is expensive with up-front cost and maintenance.
A torus (donut) antenna is similar to those round wireless routers that businesses use to mount in an office ceiling. This is not ideal for outdoor use.
A parabolic grid antenna looks like a dome but with a more rectangular feature with grid-like openings. This antenna is expensive with up-front cost and maintenance.
While investigating an issue tied to authentication redirects, the network consultant discovers that the client is being redirected to an HTTP rather than an HTTPS site.
Which of the following terms BEST describes this issue?
- Encryption protocol mismatch
- Captive Portal
- Channel Utilization
- Disassociation
- Captive portal
Most captive portal issues arise because the redirect does not work. The captive portal should use HTTPS. Most modern browsers will block redirection to sites that do not use TLS.
The client or access point can use disassociation and deauthentication frames to notify the other party that it has ended a connection.
Channel utilization can be measured from the access point or using a Wi-Fi analyzer. As a design goal, a channel should exhibit no more than 50% utilization.
An encryption protocol mismatch will cause the connection to fail, even if the correct credentials are supplied.
To increase wireless bandwidth in an office space, an engineer tests a few configurations. In doing so, the engineer learns that by manipulating the 20 MHz frequency a wireless product will obtain more bandwidth.
Which of the following implementations refers to using this approach as a solution?
- Channel bonding
- MU-MIMO
- Unidirectional antenna
- Omnidirectional antenna
- Channel bonding
802.11n can obtain more bandwidth with the option to use two adjacent 20 MHz channels as a single 40 MHz channel, referred to as channel bonding, which is a practical option only in the 5 GHz band.
A unidirectional antenna type includes the Yagi (a bar with fins) and parabolic (dish or grid) form factors. Unidirectional antennas are useful for point-to-point connections (a wireless bridge).
An omnidirectional vertical rod-type antennas send and receive signals in all direction more-or-less equally. Access points with an omnidirectional antenna should ideally be ceiling-mounted for the best coverage.
Multiuser multiple input multiple output (MU-MIMO) or beamforming allows an access point (AP) to use its multiple antennas to overcome limitations with simultaneous communications to stations.
An officer floor is requesting a new wireless network. Users are requesting faster data rates.
Network administrators want to use wireless technology with the most individual channels to choose from and to worry less about wireless interference from other wireless technologies.
Which of the following technologies will the office MOST likely use? (Select two.)
- 802.11n
- 5.0GHz
The 5 Ghz frequency band supports more individual channels than the 2.4 Ghz band. It also suffers less from congestion and interference, meaning it supports higher data rates.
The 802.11n wireless standard provides more bandwidth than previous standards. Its data rates are 288.8 Mbps for a single channel and 600 Mbps for bonded channels.
The 2.4 Ghz band supports less individual channels and has a greater risk of interference from other wireless technologies, such as Bluetooth, that also use the 2.4 Ghz band. Meaning, it has lower data rates than 5.0 Ghz.
The 802.11g wireless standard has a data transfer rate of up to 54 Mbps, the same as 802.11a. 802.11g does not support the 5 Ghz band.
A network engineer is determining where an antenna should be installed on the businesses’ property.
What is the engineer considering when they refer to the orientation of the wave propagating from the antenna?
- Effective isotropic radiated power (EIRP)
- Channel Overlap
- Polarization
- Received Signal Strength Indicator (RSSI)
- Polarization
Polarization refers to the orientation of the wave propagating from the antenna to maximize signal strength; the transmission and reception antennas should normally use the same polarization.
Channel overlap refers to interference issues resulting from multiple access points that are all in range of one another and are configured to use similar wavelengths.
The Received Signal Strength Indicator (RSSI) is the strength of the signal from the transmitter at the client end.
The power at which an access point transmits is configurable. Effective Isotropic Radiated Power (EIRP) is calculated as the sum of transmit power, antenna cable/connector loss, and antenna gain.
The wireless access points (APs) on a large building floor have different names depending on the room. Employees and customers are confused and are constantly calling IT support to get the best wireless signal to work with as they constantly must change the AP connection.
How can a network administrator improve wireless signals across the entire floor and provide a simple way to use the wireless network?
- Create ad hoc connections
- Use Wi-Fi 6 APs
- Set limit on power output
- Set up an extended service set (ESS)
- Set up an extended service set (ESS)
A wireless AP makes up an infrastructure basic service set (BSS). Multiple BSS may group together to form an extended service set (ESS) to boost wireless signals and a single AP name for the connection.
An ad hoc topology is also known as an Independent Basic Service Set (IBSS). The wireless adapter allows connections to and from other devices as a small workgroup.
Wi-Fi 6 (802.11ax) aims at providing 10G connection speeds using a 6 GHz frequency band. The APs configurations are more relevant in this case than the type of AP.
Limiting power output reduces the AP frequency range. Regulatory policies can require reducing power in restricted areas near military or government buildings.
