Unit 1

Question 1

How long can you run an Ethernet cable?

Answer 1

100 meters

Question 2

How long can you run a fibre cable?

Answer 2

550 metres

Question 3

What are some advantages of wireless network?

Answer 3

Fast installation, no wiring, access to network anywhere in range

Question 4

What are some disadvantages to wireless networking?

Answer 4

Lower security, slower network, interference

Question 5

What are the WiFi modes?

Answer 5

Ad Hoc Mode, Infrastructure mode, Mesh Mode, Monitor Mode, Promiscuous Mode, Repeater Mode, Bridged Mode

Question 6

What is Ad Hoc Mode?

Answer 6

Independent devices without any infrastructure (I/BSS)

Question 7

What is Infrastructure Mode?

Answer 7

Consists of APs, BSA (Basic Service Area, SSID, Distribution system (router)

Question 8

What is Mesh mode?

Answer 8

Access points can communicate to all other access points, if one goes down it reconnects to another node

Question 9

What is Monitor mode?

Answer 9

Sniffing raw traffic, used for design, does not need to be on authenticated

Question 10

What is promiscuous mode?

Answer 10

Sniffing raw traffic on the network, after is has been connected/authenticated

Question 11

What is repeater mode?

Answer 11

Rebroadcasts existing WiFi network

Question 12

What is bridged mode?

Answer 12

Borrows existing wireless internet using a different SSID and password (two networks, one internet)

Question 13

What does a WLAN controller do?

Answer 13

Extended Service Set (different channels), creates large networks and controls devices on them

Question 14

What are the IEEE standards?

Answer 14

802.11b, a, g, n, and ac

Question 15

What are the primary differences between 2.4 and 5 Ghz?

Answer 15

11 channels vs 24 channels
5 Mhz apart vs 20 mhz apart
20 mhz wide vs 20-40 mhz
3 non-overlapping channels vs all

Question 16

What standards are 2.4 Ghz?

Answer 16

B, G, N

Question 17

What standards are 5 Ghz

Answer 17

A, N, AC

Question 18

What has more interference, 2.4 or 5 ghz?

Answer 18

2.4 ghz

Question 19

What is the top speed of 802.11 n

Answer 19

600 mbits/s

Question 20

What is the top speed of 802.11a/g

Answer 20

54 mbits/s

Question 21

What is the top speed of 802.11 ac

Answer 21

6.93 Gbits/s

Question 22

What does FHSS stand for?

Answer 22

Frequency Hopping Spread Spectrum

Question 23

What does DSSS standard for

Answer 23

Direct-Sequence Spread Spectrum

Question 24

What does OFDM stand for?

Answer 24

Orthogonal Frequency-Division Multiplexing

Question 25

What are the differences between modulations FHSS, DSSS, and OFDM?

Answer 25

FHSS: Radio hops (one band at a time), not used often, receiver synchronized with transmitter DSSS: Whole chunk, multiple bands at once OFDM: Multiple bands together, better protection from RF

Question 26

What are the types of antennas?

Answer 26

Omni-directional (dipole), semi-directional (yagi, patch), Parabolic Grid

Question 27

What does an omni-directional antenna do?

Answer 27

Home router - can be oriented different directions, weak signal spots above and below antenna

Question 28

What does a semi-directional antenna do?

Answer 28

Yagi: Long, horizontal, transmits in one direction, requires precision pointing (fixed point to point) Patch: flat surface, wider transmission, point to point or multi point

Question 29

What does parabolic grid do?

Answer 29

Many directions, long distance point-to-point, (Teta's satellite)

Question 30

What is open authentication?

Answer 30

No security, anyone can connect, requests IP address

Question 31

What is WEP?

Answer 31

Wired Equivalent Privacy - encrypted but not secure any more

Question 32

What is WPA?

Answer 32

Wireless Protected Access - increased protection. Pre-Shared Key (PSK) exchange and 4-way handshake

Question 33

What does TKIP stand for?

Answer 33

Temporal Key Integrity Protocol - 128-bit key for each packet

Question 34

What is WPA2?

Answer 34

Enhanced security WPA, not interopable with WPA, uses AES (Advanced Encryption Standard) instead of TKIP

Question 35

What is WPA-2 enterprise

Answer 35

Radius authentication - requires central database to authenticate users (infrastructure mode)

Question 36

Why does 2.4 Ghz have more interference?

Answer 36

More common devices, like cordless phones?

Question 37

What is MIMO?

Answer 37

essential part of wireless in, allows many connections in and out

Question 38

What are the control plane and data plane?

Answer 38

Control plane manages channels, frequency and protocols, while data plan manages data, usernames and passwords

Question 39

How do you secure a tunnel?

Answer 39

pre-shared key on both sides