Chapter 14: Wireless Networking Flashcards by Melissa Nyberg

The ____ standard defines both how wireless devices communicate and how to secure that communication.

802.11

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What is Wi-Fi?

A family of protocols based on IEEE 802.11 standards.

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What is a Wireless Access Point (WAP or AP)?

A device designed to interconnect wireless network nodes with wired networks and also bridges wireless network segments to wired network segments.

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What is the 802.11 network operation mode where two or more devices communicate directly without any other intermediary hardware?

ad hoc mode

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What is the 802.11 network operation mode that uses one or more WAPs?

infrastructure mode

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Two or more wireless nodes communicating in ad hoc mode form a/an ____.

IBSS (Independent Basic Service Set)

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A single WAP servicing a given area is called a/an ____.

BSS (Basic Service Set)

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Multiple WAPs servicing an area is called a/an ____.

ESS (Extended Service Set)

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What is a Basic Service Set Identifier (BSSID)?

The MAC address of a wireless access point.

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What is a 32-bit identification string, sometimes called a network name, that’s inserted into the header of each data packet processed by a WAP (wireless access point)?

Service Set Identifier (SSID)

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A spread-spectrum broadcasting method defined in the 802.11 standard that sends data out on different frequencies at the same time is called ____.

Direct-Sequence Spread-Spectrum (DSSS)

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A spread-spectrum broadcasting method defined in the 802.11 standard that sends data on one frequency at a time, constantly shifting (or hopping) frequencies is called ____.

Frequency-Hopping Spread-Spectrum (FHSS)

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A spread-spectrum broadcasting method defined in the 802.11 standard that combines the multiple frequencies of DSSS with FHSS’s hopping capability is called ____.

Orthogonal frequency-division multiplexing (OFDM)

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Every Wi-Fi network communicates on a ____, a portion of the available spectrum.

channel

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For the ____GHz band, the 802.11 standard defines 14 channels (US limits it to channels 1-11) of 20 MHz each.

2.4 GHz

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What three channels in the 2.4 GHz band should be used on WAPs to avoid overlap?

1, 6, and 11

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The versions of 802.11 that use the ____GHz and ____GHz bands use automatic channel switching and in general have around 40 different channels in the spectrums.

5.0 GHz, 6.0 GHz

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Is radio a half-duplex or full-duplex transmission method?

half-duplex

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Wi-Fi networks use carrier-sense multiple access with ____ (CSMA/____)?

collision avoidance (CSMA/CA)

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Current CSMA/CA Wi-Fi devices use the ____ method for collision avoidance.

Distributed Coordination Function (DCF)

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802.11-1997
Frequency
Spectrum
Speed
Range

Frequency: 2.4 GHz
Spectrum: DSSS
Speed: 2 Mbps
Range: ~300 feet

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802.11b
Frequency
Spectrum
Speed
Range

Frequency: 2.4 GHz
Spectrum: DSSS
Speed: 11 Mbps
Range: ~300 feet

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802.11a
Frequency
Spectrum
Speed
Range

Frequency: 5.0 GHz
Spectrum: OFDM
Speed: 54 Mbps
Range: ~150 feet

802.11g
Frequency
Spectrum
Speed
Range

Frequency: 2.4 GHz
Spectrum: OFDM
Speed: 54 Mbps
Range: ~300 feet

802.11n (Wi-Fi 4) Frequency Spectrum Speed Range

Frequency: 2.4 GHz Spectrum: OFDM (QAM) Speed: 100+ Mbps Range: ~300 feet

____ is a feature in 802.11n and later WAPs that enables them to make multiple simultaneous connections called streams.

Multiple Input/Multiple Output (MIMO)

____ is a multiple-antenna technology in 802.11n WAPs that helps get rid of dead spots.

Transmit beamforming

802.11ac (Wi-Fi 5) Frequency Spectrum Speed Range

Frequency: 5.0 GHz Spectrum: OFDM (QAM) Speed: Up to 1 Gbps Range: ~300 feet

____ is a feature of 802.11ac and later networking that enables a WAP to broadcast to multiple users simultaneously.

Multi-User MIMO (MU-MIMO)

802.11ax (Wi-Fi 6/6E) Frequency Spectrum Speed Range

Frequency: 2.4 GHz, 5.0 GHz, 6.0 GHz Spectrum: OFDMA (1024 QAM) Speed: Up to 10 Gbps Range: ~300

What is Wi-Fi Protected Setup (WPS) and how does it work?

An automated and semi-automated process to connect a wireless device to a WAP. The process is either pressing a button on the device or pressing the button and then entering a PIN code.

____ is an early wireless security protocol for Wi-Fi that uses the RC4 encryption algorithm and is no longer used due to major security vulnerabilities.

WEP or Wired Equivalent Privacy

____ is a wireless security protocol that addresses weaknesses and acts as an upgrade to WEP. It also supports authentication using EAP.

WPA or Wi-Fi Protected Access

____ is an authentication wrapper that ___-compliant applications can use to accept one of many types of authentication. It is a general-purpose authentication wrapper mainly used in wireless networks.

EAP or Extensible Authentication Protocol

____ is a port-based authentication network access control mechanism for networks. It's a complete authentication standard designed to force devices to go through a full AAA process to get anywhere past the interface on a network connection device such as a WAP (aka. network access server or NAS).

802.1X

____ is the consumer name for the IEEE 802.11i standard and the replacement for the WPA protocol. It uses the AES (Advanced Encryption Standard) algorithm.

WPA2

The process of using a mobile device's built-in GPS capabilities and mobile networking capabilities to set geographical constraints on where the mobile device can be used is called ____.

geofencing

A switch that's designed to handle a number of WAPs simultaneously and does the job of configuring them is called a/an ____.

wireless LAN controllers

____ is a method to load-balance wireless network clients associated with a single SSID. It distributes clients across many VLANs to avoid excessive levels of broadcast traffic.

VLAN pooling

____ is a standard that enables wireless access points (WAPs) to receive their power from the same Ethernet cables that transfer their data.

PoE or Power over Ethernet

An ____ radiates signal outward from the WAP in all directions.

omnidirectional antenna

The strengthening and focusing of radio frequency output from a WAP is called ____.

gain

An antenna that focuses all of its transmission energy in a single, relatively narrow direction is called ____. It's design limits its ability to receive signals that are not aligned with the focused direction.

unidirectional

____ are flat, plate-shaped antennas that generate a half-sphere beam and are placed on walls.

Patch antennas

All radio signals have a property called ____, which describes the orientation of the radio waves which depends on the antenna.

polarization

____ wireless bridges can only communicate with a single other bridge and are used to connect two wired network segments.

Point-to-point

____ wireless bridges can talk to more than one other bridge at a time and can connect multiple network segments.

Point-to-multipoint

Wi-Fi ____ is the loss of packets due to an overworked WAP.

jitter

Wi-Fi ____ is when data stops moving for a moment due to a WAP being unable to do the work.

latency

____ is when the frequency of a band is filled to capacity due to a large number of devices using the same bandwidth.

Bandwidth saturation

What are the three physical problems that cause attenuation in Wi-Fi networks, the progressive loss of radio signal strength as the radio wave passes through different mediums?

Absorption Reflection Refraction

A ____ is a Wi-Fi network implementation used in some public facilities that directs attempts to connect to the network to an internal Web page for that facility; generally used to force terms of service on users.

captive portal

What is the progressive loss of radio signal passing through different media called?

Attenuation

Which technology enables use of a WAP without directly connecting the WAP to an AC power outlet?

PoE

What feature enabled 802.11n networks to minimize dead spots?

Transit beamforming

When setting up WPA2-PSK on your wireless network, you have the option to choose TKIP or AES. Which should you implement?

AES

What type of server supports EAP-encrypted passwords in accordance with the 802.1X standard?

RADIUS server