Chapter 4 - 802.11 MAC Frames

Question 1

What type and subtype designation is applied to a beacon frame?
a. Type 00 and subtype 0001
b. Type 00 and subtype 1000
c. Type 01 and subtype 0001
d. Type 01 and subtype 1000

Answer 1

Type 00 and subtype 1000

00 - management
01 - control
02 - data

Question 2

Communication between two mesh STA use how many Address fields?
a. One
b. Two
c. Three
d. Four

Answer 2

Four (most will always use three)

CTS will use one (RA)

Question 3

The duration field describes which of the following?
a. the time to transmit the frame that carries it
b. the time that has elapsed in the current conversation
c. the time remaining for the frames to follow this one in a given transmission
d. the time remaining for the frames to follow this one in a given transmission, including spacing

Answer 3

the time remaining for the frames to follow this one in a given transmission, including spacing

Question 4

Beacon frames are normally transmitted in what interval?
a. every 100 ms
b. every 100 Tu
c. when contention allows
d. A&C
e. B&C
f. None of the above

Answer 4

every 100 Tu = 102.4 microseconds

Question 5

A power management subfield value of 1 indicates which of the below?
a. a station is asleep, and frames must be buffered until the next waking period
b. a station is awake and ready to receive frames
c. a station will be awake after this exchange, and able to receive more frames
d. a station will be asleep after this exchange and frames must be buffered until the next waking period

Answer 5

a station will be asleep after this exchange and frames must be buffered until the next waking period

Question 6

An FCS has the most in common with which of the following?
a. a diffie-hellman exchange
b. a SHA-256 hash of a file
c. a functional control section
d. start frame delimiter

Answer 6

a SHA-256 hash of a file

Question 7

An 802.11n system is capable of which of the following channel widths?
a. 20 Mhz
b. 40 Mhz
c. 20 and 40 Mhz
d. 20, 40, and 80 Mhz

Answer 7

20 and 40 Mhz

802.11ac (80 and 160 MHz)

Question 8

You are using MS-CHAPv2 to secure your enterprise network, which of the following should be present in AKMP Suite OUI, in the RSN fields of your beacon frames?
a. CCMP
b. RSA
c. TKIP
d. 802.1X

Answer 8

802.1X (MS-CHAPv2 is part of PEAP/802.1X)

Question 9

In an 802.11a network, which of the following should be sent from the AP immediately after your data frame?
a. BlockAck
d. BlockAckRequest
c. AckRequest
d. QoS Null data
e. None of the above

Answer 9

none of the above (ACK)
BlockAck became available in 802.11ac

Question 10

What WMM category should a VoIP phone transmission be under, and what should the values be?
a. AC_BE, Lowest ECW Max/Min
b. AC_VI, Highest ECW Max/Min
c. AC_VO, Lowest ECW Max/Min
d. AC_VO, Highest ECW Max/Min

Answer 10

AC_VO, Lowest ECW Max/Min