Wireless Networking

Question 1

Designed for point-to-point communications with another device, and isn’t compatible with other standards. It may also be prone to interference and have little or no security measures.

Answer 1

RF

Question 2

A technology which allows identification and communication between nodes using electromagnetic fields.

Answer 2

RFID

Question 3

Most commonly used for inventory tracking, identification badges, and even implanted chips to identify pets in case they’re lost.

Answer 3

RFID

Question 4

Operates in the same 2.4 GHz RF band used by Wi-Fi and is commonly used to connect peripherals to computers and mobile devices.

Answer 4

Bluetooth

Question 5

A set of standards based on RFID, and commonly found on mobile devices such as smartphones and only supports communications up to 20cm away and at speeds up to 424 kbps, so it’s usually only used either for small amounts of data like contactless payment systems or authentication, or else for configuration data that can bootstrap a faster Bluetooth or Wi-Fi connection.

Answer 5

NFC Near Field Communication

Question 6

A 2.4 GHz radio protocol similar to but separate from Bluetooth which operates at low speeds over distances up to 30 meters, and is used primarily to manage sensors such as fitness trackers, medical devices, and watches.

Answer 6

ANT+

Question 7

A proprietary wireless standard maintained by Silicon Labs that uses the 800-900 MHz ISM band, with precise frequencies varying by country. supports throughput up to 40 kbps over distances of 10-100m, but it allows nodes to form a mesh network such that even if two nodes can’t directly communicate, they can relay data through intermediate nodes. Used for interoperable monitoring and remote control of home automation systems such as lighting control, thermostats, household appliances, and security systems.

Answer 7

Z-Wave

Question 8

An open standard based on the IEEE 802.15.4 PAN standards which use a variety of ISM bands, with 2.4 GHz and 915 MHz bands being the most common.

Answer 8

ZigBee

Question 9

Uses multiple antennas to simultaneously transmit and receive separate data streams on the same channel

Answer 9

MIMO

Question 10

Devices use haptic confirmation for sharing data wirelessly.

Answer 10

NFC (Near Field Communication)

Question 11

Devices are paired using a code for sharing data wirelessly

Answer 11

Bluetooth

Question 12

Devices are placed in close proximity within line of sight for sharing data wirelessly.

Answer 12

IR (Infrared)

Question 13

Devices are connected via a wire for sharing data or connectivity.

Answer 13

Tethering

Question 14

Centrally managed from a central wireless access point (WAP) that mediates all communications

Answer 14

Infrastructure networks

Question 15

Have no WAP: clients communicate directly with each other.

Answer 15

Ad hoc\ or peer-to-peer networks

Question 16

Supported by some new devices, especially distributed WAPs and IoT devices.

Answer 16

WMN

Question 17

A string of up to 32 octets that can be used to uniquely identify it to clients

Answer 17

service set identifier (SSID)

Question 18

Equipment tends to be more expensive and the range is shorter, but it has 23 non-overlapping channels and typically interference is less.

Answer 18

5 GHz ISM

Question 19

These frequencies support a very high data rate, but typically don’t penetrate walls.

Answer 19

60GHz millimeter wave

Question 20

Only supported network speeds of 2Mbps, and devices from different manufacturers had poor interoperability.

Answer 20

The original 1997 802.11 standard

Question 21

Supports speeds of up to 11Mbps on the 2.4GHz band.

Answer 21

802.11.b

Question 22

Supports speeds of up to 54Mbps on the 5 GHz band

Answer 22

802.11a

Question 23

Supports speeds up to 54Mbps over the 2.4 GHz band

Answer 23

802.11g

Question 24

Supports speeds up to 600 Mbps over either the 2.4 GHz or 5 GHz band, if all 4 spatial streams are used. Introduced a number of technologies to boost speed, including MIMO and wider 40MHz channels via channel bonding (HT mode)

Answer 24

802.11n

Question 25

Supports speeds of up to 6.93 Gbps in the 5GHz band using OFDM encoding, if all 8 spatial streams are used. Uses still-wider 80MHz channels (VHT), more MIMO antennas, and beamforming technology

Answer 25

802.11ac

Question 26

Original Wi-Fi standard, It uses the RC4 encryption cipher

Answer 26

WEP: Wired Equivalent Privacy

Question 27

Encrypts traffic using Temporal Key Integrity Protocol (TKIP)

Answer 27

WPA: Wi-Fi Protected Access

Question 28

Mandatory support for 128-bit encryption using the strong and well-regarded Advanced Encryption Standard(AES) cipher

Answer 28

WPA2

Question 29

What is the strongest current encryption standard for Wi-Fi?

Answer 29

WPA2 in AES-only mode

Question 30

Uses a passphrase of between 8 and 63 ASCII characters, manually distributed to each authorized user

Answer 30

WPA-Personal: Also called pre-shared key (PSK)

Question 31

Connecting clients are only allowed to communicate to an external authentication server, usually RADIUS-based, with a username and password

Answer 31

WPA-Enterprise: Also known as 802.1x mode

Question 32

Allows the key to be shared with a new device by other methods like a PIN, a push-button pairing mechanism, or NFC pairing

Answer 32

WPS: Wi-Fi Protected Setup

Question 33

Turns routing off entirely and causes the router to function as a switch and is useful if you want to add a new WAP to a LAN that already has enough router

Answer 33

Bridge Mode

Question 34

Lets clients dynamically open incoming ports, but instead of individual rules configured on the router, it’s a standard supported by many devices and applications

Answer 34

Universal Plug and Play (UPnP)

Question 35

Redirect all incoming traffic on a given port or port range to a specific local host

Answer 35

Port Forwarding rules

Question 36

Opens all ports that aren’t otherwise forwarded to the DMZ host.

Answer 36

Demilitarized Zone (DMZ)

Question 37

Making sure that time-sensitive traffic like VoIP, streaming video, or games gets handled without delay, even when it means that traditional file transfers such as web or FTP connections take longer.

Answer 37

Quality of Service (QoS)

Question 38

Troubleshooting that moves down the network stack from network applications down through the operating system

Answer 38

top-down approach

Question 39

Troubleshooting that moves up through the network stack from physical connection to NIC drivers and the operating system

Answer 39

bottom-up approach