Wireless Questions 2

Here you will find answers to Wireless – Part 2

If you are not sure about Wireless, please read my Wireless tutorial and Basic Wireless Terminologies

Question 1

You have finished physically installing an access point on the ceiling at a newly opened office. At a minimum, which parameter must you configure on the access point in order to allow wireless clients to operate on it?

A. SSID
B. AES
C. TKIP
D. PSK
E. None of the other alternatives apply

Answer: A

Question 2

Part of the wireless LAN is shown below:

What two facts can be determined from the diagram of the WLAN shown above? (Choose two)

A. Access points in each cell must be configured to use channel 1
B. The network diagram represents an extended service set (ESS)
C. The two APs should be configured to operate on different channels
D. The area of overlap of the two cells represents a basic service set (BSS)
E. The area of overlap must be less than 10% of the area to ensure connectivity
F. There are too many hosts on this WLAN

Answer: B C

Question 3

A single 802.11g access point has been configured and installed in the center of a square shaped office. A few wireless users are experiencing slow performance and drops while most users are operating at peak efficiency. From the list below, what are three likely causes of this problem? (Choose three)

A. Null SSID
B. Mismatched TKIP encryption
C. Cordless phones
D. Antenna type or direction
E. Mismatched SSID
F. Metal file cabinets

Answer: C D F

Explanation

802.11g operates in 2.4 GHz ISM band. Some popular devices and technologies can interfere 802.11g signal:

+ Newer cordless phones
+ Bluetooth
+ Microwaves
+ Metal surface (can cause interference)
+ Antenna (can reduce wireless signal)

Question 4

Three access points have been installed and configured to cover a small remote office. What term defines the wireless topology?

A. SSID
B. BSS
C. ESS
D. IBSS
E. ASS

Answer: C

Question 5

Two workers have established wireless communication directly between their wireless laptops. What type of wireless topology has been created by these employees?

A. ESS
B. IBSS
C. SSID
D. BSS

Answer: B

Explanation

Independent Basic Service Set – IBSS (ad hoc mode) does not use an AP. It allows two devices to communicate directly.

Basic Service Set (BSS) is a single wireless LAN created with an AP and all devices that associate with that AP.

Extended Service Set (ESS) consists of multiple APs, allowing roaming in a larger coverage area.

Question 6

802.1b is being utilized in the wireless network. Which spread spectrum technology does the 802.1b standard define for operation in this network?

A. FHSS
B. IR
C. DSSS and FHSS
D. DSSS
E. IR, FHSS and DSSS

Answer: D

Explanation

Frequency Hopping Spread Spectrum (FHSS) uses all frequencies in the band, hopping to different ones. By using slightly different frequencies for consecutive transmissions, a device can hopefully avoid interference from other devices that use the same unlicensed band, succeeding at sending data at some frequencies.

Direct Sequence Spread Spectrum (DSSS) followed as the next general class of encoding type for WLANs. Designed for use in the 2.4 GHz unlicensed band, DSSS uses one of several separate channels or frequencies.

The original 802.11 WLAN standards used FHSS, but the current standards (802.11a, 802.11b, and 802.11g) do not. 802.1b uses DSSS while 802.1a & 802.1g use Orthogonal Frequency Division Multiplexing (OFDM).

(Reference: ICND1 Official Exam Certification Guide)

Question 7

Which IEEE standard is used to define Wi-Fi?

A. IEEE 802.3
B. IEEE 802.5
C. IEEE 802.11h
D. IEEE 802.11c
E. IEEE 802.11

Answer: E

Question 8

An office is using an IEEE 802.11b wireless LAN. What is the maximum data rate specified for this WLAN?

A. 11 mbps
B. 100 mbps
C. 54 mbps
D. 10 mbps
E. 1000 mbps
F. 16 mbps

Answer: A

Explanation

The maximum data rate for popular WLAN standards are listed below:

* IEEE 802.11a: 54 Mbps in the 5.7 GHz ISM band
* IEEE 802.11b: 11 Mbps in the 2.4 GHz ISM band
* IEEE 802.11g: 54 Mbps in the 2.4 GHz ISM band