Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Network+ Certification > Chapter 15 - Wireless Networking > Flashcards

Chapter 15 - Wireless Networking Flashcards

1
Q

What did the 802.11-1997 standard define

A

How wireless devices communicate and how to secure that communication. Certain features such as wireless network cards, special configuration software and the capability to run in multiple styles of networks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What two modes do 802.11 netowrks operate in

A

Ad hoc mode where two or more devices communicate directly without any other intermediary hardware.
Infrastructure mode uses a WAP that acts as a hub for all wireless clients.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is Ad Hoc mode

A

sometimes called peer-to-peer mode with each wireless node being in direct contact with each other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a Independent Basic Service Set

A

when two or more wireless nodes communicate in ad hoc mode.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is Infrastructure mode

A

Uses one or more WAPs to connect the wireless network nodes centrally - similar to physical star.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the difference between a basic service set and a extended serrvice set

A

a BSS is a single WAP in a given area, and an ESS has more access points to cover a larger area.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does a BSSID stand for and what is is

A

Basic Service Set Identifier defines the most basic infrastructure mode network. Same as MAC except in ad hoc a randomly generated number is used to function the same way

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a SSID

A

Service set Identifier is a 32 bit ID string inserted into the header of each frame.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Explain the process of Roaming

A

as clients move throughout the broadcast space they will change WAP seamlessly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the three broadcast methods defined in the 802.11 standard.

A

DSSS - Direct sequence spread spectrum
FHSS - frequency hopping spread spectrum
OFDM - Orthogonal frequency division multiplexing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Define DSSS

A

Data is sent out on different frequencies at the same time. Uses more bandwidth (22Mhz). Greater trhoughput but prone to interference.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define FHSS

A

data is sent out on one frequency at a time by constantly shifting frequencies. Low bandwidth (1 MHz). Lower throughput, but less interference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is sharing performed in a CSMA/CA network

A 
each device listens in on the network media by measuring the level of voltage currently on the wire. 
if level < threshold:
    device knows its clear
if level > threshold:
    device knows line is busy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define IFG

A

Interframe Gap is a predifined silence period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What two methods of collision avoidance is defined in the 802.11 standard

A

Distributed Coordination Function

Point Coordination Function (Not implemented)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define Distributed Coordination Function

A

DCF defines a backoff period on top tf the normal IFG wait period. Requires also that receiving nodes end an acknowledgement for every frame processed. If ack is not received the frame is resent until confirmation is received

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the speed and distance of 802.11b

A

11 Mbps at a max of 300 feet

2.4 GHz only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Give an overview of 802.11a

[standard, frequency, spectrum, speed, range]

A

Frequency: 5 GHz
Spectrum: DSSS
Speed: 54 Mbps
Range: 150 feet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Give an overview of 802.11g

[standard, frequency, spectrum, speed, range]

A 
Frequency: 5 GHz
Spectrum: OFDM
Speed: 54 Mbps
Range: 300 feet
Backwards compatible with 802.11b
20
Q

Give an overview of 802.11n

[standard, frequency, spectrum, speed, range]

A 
Frequency: 2.4 GHz
Spectrum: OFDM
Speed: 100+ Mbps
Range: 300 feet
Backwards compatible with 802.11 b/g/n
21
Q

Define MIMO

A

Multiple in Multiple Out enables the devices to make multiple simultaneous connections called streams

22
Q

Define Transmit Beamformiung

A

multiple antenna technology that helps get rid of deadspots

23
Q

What is mixed mode used for

A

also called high-throughput. the WAP sends a special packat that supports the older standards yet also can improve the speed

24
Q

What is greenfield mode used for

A

The WAP will only process 802.11n frames.

25
Q

Give an overview of 802.11 ac

[standard, frequency, spectrum, speed, range]

A 
Frequency: 5 GHz
Spectrum: OFDM
Speed: 1000 Mbps
Range: 300 feet
Backwards compatible with 802.11 a
26
Q

What is MU-MIMO

A

Gives the WAP the ability to broadcast to multiple users simulltaneously

27
Q

What is QAM

A

A special version of OFDM called quadruple-amplitude modulated. This is a type of broadcasting method.

28
Q

What are the three ways 802.11 devices address security

A

MAC address filtering, authentication and data encryption

29
Q

What is the purpose of a RADIUS server

A

stores user names and passwords enabling you to set a users rights once in the network.

30
Q

Outline the process of getting authenticated in a network with a RADIUS server

A

the supplicant contacts the Network Access Server to request permisson to access the network. The NAS collects the supplicants user name and pass and then contacts the RADIUS

31
Q

What is PPP

A

provides a secure connection between the supplicant and the NAS. Often IPsec is used in this scenario

32
Q

Explain WEP

A

Wired Equivalent Privacy usues a 64 or 128 bit encryption to scramble data. Extra code is stored in the key in the form of a IV which is 24 bits. Making WEP only 40 or 104 bit.
Encryption is static.

33
Q

What is WPA

A

Offers dynamic encryption key generation and uses TKIP to have an added 128 bit encryption key

34
Q

What changes were made with WPA2

A

AES adds a 128 block cipher

35
Q

What is a personal shared key

A

in WPA/WPA2 a key is created that must be added to any device that is connecting to the SSID

36
Q

What is a wireless controller

A

A switch that has been designed to handle a number of WAP simultaneously

37
Q

What is the difference between thick and thin clients

A

A thick client is one that can only be configured via its own interface. A Thin client is one that can only be configured by a wireless controller

38
Q

What was the purpose of Light Weight Access Point Protocol

A

LWAPP is used to ensure interoperability (between brands) and most WAPS will accept commands from any wireless controller

39
Q

What is VLAN pooling

A

a pool of VLANS for a single SSID has a number of wireless clients randomly assigned to it

40
Q

How much power can be delivered via PoE

A

Output can be as much as 25.5 watts (802.11af)

41
Q

What is the purpose of Wireless survey tools

A

help discover any other wireless networks in the area and will integrate a drawing of your floor plan with interference sources clearly marked.

42
Q

What items are required to configure a Ad Hoc network

A

SSID
IP addresses
Channel
Sharing

43
Q

What is a imnidirectional antenna

A

Radiates outward from the WAP in all directions

44
Q

What is a unidirectional antenna

A

focuses the radio wave into a beam

45
Q

What is a patch antenna

A

generate a half sphere beam

46
Q

What is the purpose of a beacon

A

WAP sends beacons at a regular interval to negotiate with devices to get on the network

47
Q

What are the two types of bridges

A

Point to Point

Point to Multipoint

Network+ Certification (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions