Wireless Networking Study Questions

What is the frequency range of the IEEE 802.11a standard? A. 2.4Gbps B. 5Gbps C. 2.4GHz D. 5GHz

5GHz The IEEE 802.11a standard runs in the 5GHz RF range.

How many non-overlapping channels are available with 802.11b? A. 3 B. 12 C. 23 D. 40

A. 3 The IEEE 802.11b and g standards provide three non-overlapping channels.

Which is the highest encryption that WPA2 can use? A. AES-CCMP B. PPK via IV C. PSK D. TKIP/MIC

A. AES-CCMP The IEEE 802.11i standard replaced Wired Equivalent Privacy (WEP) with a specific mode of the Advanced Encryption Standard (AES) known as the Counter Mode Cipher Block Chaining-Message Authentication Code (CBC-MAC) protocol. This allows AES-CCMP (AES -Counter Mode CBC-MAC Protocol) to provide both data confidentiality (encryption) and data integrity.

Which of the following types of satellites is used to provide satellite data services? A. Geosynchronous earth orbit B. Low earth orbit C. Medium earth orbit D. High earth orbit

A. Geosynchronous earth orbit

Which of the following wireless technologies boasts the highest maximum theoretical throughput? A. LTE B. HSPA+ C. 802.11g D. 802.11n

A. LTE

Suppose you work for a telecommunications carrier who is looking into providing WiMAX in a suburb of a large city. A colleague suggests that your company reserve licensed frequencies from the FCC for your service. Why? A. Licensed frequencies will suffer less interference than unlicensed frequencies B. Licensed frequencies allow users to roam farther than unlicensed frequencies C. Licensed frequencies can use multiple areas of the wireless spectrum at once, thus increasing potential throughput. D. Licensed frequencies require less-expensive equipment to transmit and receive than unlicensed frequencies.

A. Licensed frequencies will suffer less interference than unlicensed frequencies

To transmit and receive signals to and from multiple nodes in a three-story office building, what type of antenna should an access point use? A. Omnidirectional B. Unidirectional C. Bidirectional D. Tridirectional

A. Omnidirectional Defined: issues and receives wireless signals with equal strength and clarity in all directions.(commonly used by radio stations for traveling cars)

What does extended service set (ESS) ID mean? A. That you have more than one access point, and they are in the same SSID connected by a distribution system B. That you have more than one access point, and they are in separate SSIDs connected by a distribution system C. That you have multiple access points, but they are placed physically in different buildings D. That you have multiple access points, but one is a repeater access point

A. That you have more than one access point, and they are in the same SSID connected by a distribution system Extended service set ID means that you have more than one access point, they all are set to the same SSID, and they are all connected together in the same VLAN or distribution system so users can roam.

You're working on a school district's 802.11n WLAN. Within each school, several access points serve students, teachers, and administrators. So that users can move about the school with their laptops and not lose network connectivity, each of the access points must share which of the following? A. The same ESSID B. The same make and model C. The same average distance to the client D. The same location

A. The same ESSID

What is the maximum data rate for the 802.11b standard? A. 6Mbps B. 11Mbps C. 22Mbps D. 54Mbps

B. 11Mbps The IEEE 802.11b standard provides a maximum data rate of up to 11Mbps. With an actual data rate of 5 Mbps.

How many non-overlapping channels are available with 802.11a? A. 3 B. 12 C. 23 D. 40

B. 12 The IEEE 802.11a standard provides up to 12 non-overlapping channels, or up to 23 if you add the 802.11h standard.

What frequency band is used by 802.11b, 802.11g, and 802.11n? A. 1.5 GHz B. 2.4 GHz C. 5 GHz D. 11 GHz

B. 2.4 GHz 802.11n also uses the 5 GHz band

With CSMA/CA, due to the use of ACK packets to verify transmissions the 802.11 networks require more overhead than the 802.3 networks. In reality, the 802.11g network which is rated for a max of 54 MBps, only achieves this much? A. 10-15 B. 20-25 C. 30-35 D. 40-45

B. 20-25 wireless networks tend to achieve between one-third and one-half of their theoretical maximum throughput.

Your office currently runs a mix of 802.11b and 802.11g clients. Rumor has it that your company is about to merge with another company that uses a different wireless technology. Which of the following would be compatible with what your WLAN currently runs? A. 802.11a B. 802.11n C. Bluetooth D. WiMAX

B. 802.11n

Which of the following does not cause multipath signals? A. Scattering B. Attenuation C. Diffraction D. Reflection

B. Attenuation

Which of the following will help an access point's transmissions reach farther? A. Limiting the number of stations that may associate with the access point B. Boosting its signal strength C. Using the highest possible channel in the frequency band D. Configuring it to use 802.11n onlyB. Boosting its signal strength

B. Boosting its signal strength

Which spread-spectrum technology does the 802.11b standard define for operation? A. IR B. DSSS C. FHSS D. DSSS and FHSS E. IR, FHSS, and DSSS

B. DSSS The IEEE 802.11b standard uses Direct Sequence Spread Spectrum (DSSS). If you are running 802.11g, it uses Orthogonal Frequency Division Multiplexing (OFDM).

When a signal jumps between several different frequencies is the definition of what spread-spectrum signaling? A. NPSS B. FHSS C. APSS D. DSSS

B. FHSS

Which is not a difference in the 802.11n wireless standard that allows for higher throughput? A. Channel bonding B. Frame bonding C. Frame aggregation D. MIMO

B. Frame bonding Channel bonding, frame aggregation, MIMO (multiple input-multiple output) and higher modulation rates allow 802.11n for higher throughput

You connect a new host to your company's wireless network. The host is set to receive a DHCP address and the WEP key is entered correctly. However, the host cannot connect to the network. What can the problem be? A. DNS is not configured on the host. B. MAC filtering is enabled on the AP. C. The network has run out of wireless connections. D. The host is enabled to run 802.11b and 802.11g.

B. MAC filtering is enabled on the AP. If everything is correctly configured on the host, then MAC filtering would stop the host from connecting to the AP. If you try to connect and can't, check the AP's settings.

Which devices can interfere with the operation of a wireless network because they operate on similar frequencies? (Choose two.) A. Copier B. Microwave oven C. Toaster D. Cordless phone E. IP phone F. AM radio

B. Microwave oven D. Cordless phone If you are running 802.11b/g frequency, which most networks are, then you can receive interference from microwave ovens and cordless phones.

Which of the following is not true about multipath signaling? A. The more obstacles a wireless signal reflects or diffracts off, the better chance it has of reaching its destination. B. Multipath signaling uses less energy and results in clearer reception than line-of-sight signaling. C. Given that they follow multiple paths to their destination, signals will arrive at the same destination at slightly different times. D. The more obstacles between a wireless transmitter and receiver, the more signal fading will occur.

B. Multipath signaling uses less energy and results in clearer reception than line-of-sight signaling.

What is the most severe flaw affecting wireless signals? A. Reflection B. Noise C. Scattering D. Attenuation

B. Noise

Which wireless LAN design ensures that a mobile wireless client will not lose connectivity when moving from one access point to another? A. Using adapters and access points manufactured by the same company B. Overlapping the wireless cell coverage by at least 10 percent C. Configuring all access points to use the same channel D. Utilizing MAC address filtering to allow the client MAC address to authenticate with the surrounding APs

B. Overlapping the wireless cell coverage by at least 10 percent If you are running an extended service set (meaning more than one AP with the same SSID name), you need to overlap the cell coverage by 10 percent or more so clients will not drop out while roaming.

When a mobile WLAN user roams from access point A's range into access point B's range, what does it do automatically to maintain network connectivity? A. Associate with access point B in order to communicate with access point A B. Reassociate with access point B C. Reestablish its connection with access point A on another channel D. Nothing; the user must reestablish network connectivity manually

B. Reassociate with access point B

You have installed a point-to-point connection using wireless bridges and Omni-directional antennas between two buildings. The throughput is low. What can you do to improve the link? A. Replace the bridges with APs. B. Replace the Omni-directional antennas with Yagis. C. Configure 802.11a on the links. D. Install amps to boost the signal.

B. Replace the Omni-directional antennas with Yagis. You need to use directional antennas, like a Yagi, in order to get the best signal between antennas.

802.11n uses MIMO. How does this optimize throughput to gain the high speed advantage that 802.11n provides? A. By specifying an acknowledgment of each and every frame, 802.11n provides better overhead. B. Several frames are sent by several antennae over several paths and are then recombined by another set of antennae. C. One frame at a time is sent, but faster than in 802.11g because multiple antennas are used (multiple-in, multiple-out). D. MIMO packs smaller packets into a single unit, which improves throughput.

B. Several frames are sent by several antennae over several paths and are then recombined by another set of antennae. 802.11n MIMO sends multiple frames by several antennae over several paths. The frames are then recombined by another set of antennae to optimize throughput and multipath resistance. This is called spatial multiplexing.

What part of a cellular network manages handoff? A. The client B. The base station C. The MSC D. The central office

B. The base station

Suppose a user on your office network has changed the channel on which his wireless NIC communicates. Assuming the wireless connection is his only access to the LAN, what will happen when he next tries to send an e-mail? A. The e-mail program will take longer than usual to send his message. B. The e-mail program will respond with a message indicating it could not connect to the mail server. C. The e-mail program will send the message without problems. D. The e-mail program will request the user to supply his logon credentials again before sending the message.

B. The e-mail program will respond with a message indicating it could not connect to the mail server.

Which frequency is affected by cordless phone use? A. 5-GHz B. 1.5-GHz C. 2.4-GHz D. 9-GHz

C. 2.4-GHz

What is the frequency range of the IEEE 802.11g standard? A. 2.4Gbps B. 5Gbps C. 2.4GHz D. 5GHz

C. 2.4GHz The IEEE 802.11b and IEEE 802.11g both run in the 2.4GHz RF range.

How wide are the channels used in 802.11n in order to gain the large bandwidth that the specification provides? A. 22MHz B. 20Mhz C. 40Mhz D. 100Mhz

C. 40Mhz 802.11n uses two 20MHz-wide channels to create a 40Mhz-wide channel, which provides over 100Mbps wireless.

What is the throughput speed of the 802.11n wireless standard? A. 10-135 Mbps B. 45-500 Mbps C. 65-600 Mbps D. 100-800 Mbps

C. 65-600 Mbps

If your wireless stations are configured to perform passive scanning, what do they need from an access point to initiate association? A. A request to send B. An alert frame C. A beacon frame D. Nothing; they will find the access point on their own

C. A beacon frame

Which of the following 802.11 transmission requirements contributes to its inefficiency? A. Before it can associate, a station must listen for an access point's beacon on every channel within its frequency range. B. A source node must regularly ping the access point to ensure it is still available for transmitting data to the rest of the stations. C. A destination node must issue an acknowledgment for every packet that is received intact. D. Before transmitting, a source node must check to ensure the access point has not changed its SSID.

C. A destination node must issue an acknowledgment for every packet that is received intact.

A group of stations that share an access point are said to be part on one? A. ISS B. ESS C. BSS D. RSS

C. BSS basic service set The identifier for this group is BSSID ESS = extended service set the identifier for ESS is ESSID ISS & RSS are ? I made them up

You need to install wireless Internet access in an open warehouse environment. After installing the equipment, the technician notices varying signal strengths throughout the warehouse. How do you make sure there is full coverage? A. Turn on broadcast key rotation. B. Change the encryption method used on all the APs. C. Change the antenna placement. D. Use channel bonding. E. Use channel shaping.

C. Change the antenna placement. It is imperative that a good site survey is completed before installing your wireless network. Trying various types of antennas and their placements is the key to covering the whole wireless area.

You need to install wireless on multiple floors of a large building and maintenance area. What is your first concern before installing the APs? A. Authentication B. Encryption C. Channel overlap D. AP configuration

C. Channel overlap If you have a large area to cover with wireless, you need to be concerned with channel overlap.

On your Linux workstation, you open a terminal window and type at the command prompt iwconfig eth0 key 5c00951b22. What have you done? A. Established the wireless interface's mode of transmission. B. Established the strength with which the wireless interface will transmit data. C. Established the credentials the wireless interface will use to communicate securely with the access point. D. Established the SSID with which the wireless interface will attempt to associate.

C. Established the credentials the wireless interface will use to communicate securely with the access point.

Which two of the following techniques help to reduce overhead in 802.11n wireless transmission? A. CSMA/CA B. Asynchronous communication C. Frame aggregation D. Spread-spectrum signaling E. Channel bonding

C. Frame aggregation E. Channel bonding

You are setting up a WLAN for an insurance agency. The network includes 32 clients, three printers, two servers, and a DSL modem for Internet connectivity. What type of WLAN architecture would best suit this office? A. Ad Hoc B. Interstitial C. Infrastructure D. Round robin

C. Infrastructure

Which additional configuration step is necessary in order to connect to an access point that has SSID broadcasting disabled? A. Set the SSID value in the client software to public. B. Configure open authentication on the AP and the client. C. Set the SSID value on the client to the SSID configured on the AP. D. Configure MAC address filtering to permit the client to connect to the AP.

C. Set the SSID value on the client to the SSID configured on the AP. If you disable SSID broadcasting, which you should, then you must configure the SSID name on the clients that need to connect to the AP.

As the network manager for a small business, you have been asked to evaluate high-speed, packet-switched wireless data services that your company's users can use at their desks, in their cars, and at their homes within your metropolitan area. Which two of the following meet those criteria, and are therefore candidates for evaluation? A. 802.11g B. 802.11n C. WiMAX 2 D. HSPA+ E. LTE

C. WiMAX 2 E. LTE

What's the distance a mobile device should remain within an access point to stay within optimal transmission speeds A. 50 ft B. 100 ft C. 200 ft D. 300 ft

D. 300 ft

What is the maximum data rate for the 802.11a standard? A. 6Mbps B. 11Mbps C. 22Mbps D. 54Mbps

D. 54Mbps The IEEE 802.11a standard provides a maximum data rate of up to 54Mbps. With a effective data rate of 11 and 18 Mbps.

Which wireless standard allows you to channel-bond to increase bandwidth and uses both the 2.4Ghz and 5Ghz frequencies? A. 802.11b B. 802.11g C. 802.11a D. 802.11n

D. 802.11n 802.11n uses channel bonding of both the 2.4Ghz range and the 5Ghz range to get increased bandwidth of over 100Mbps.

The Wireless Spectrum spans what frequencies? A. 0 KHz to 150 GHz B. 5 KHz to 200 GHz C. 7 KHz to 250 GHz D. 9 KHz to 300 GHz

D. 9 KHz to 300 GHz

Your organization is expanding and plans to lease 3000 square feet of space in a nearby building. Your supervisor asks you to conduct a site survey of the space. If conducted properly, which of the following will your site survey reveal? A. The optimal quantity and locations of access points for the WLAN B. All potential sources of EMI C. The distance between each workgroup area and telco room D. All of the above

D. All of the above

In the 802.11 standard, IEEE specifies what type of access method? A. Beacon passing B. Demand priority C. CSMA/CD D. CSMA/CA

D. CSMA/CA

What is one reason that WPA encryption is preferred over WEP? A. A WPA key is longer and requires more special characters than the WEP key. B. The access point and the client are manually configured with different WPA key values. C. WPA key values remain the same until the client configuration is changed. D. The values of WPA keys can change dynamically while the system is used.

D. The values of WPA keys can change dynamically while the system is used. WPA is cool because it is easy to configure and works great. Type in a passphrase (assuming you're using Pre-Shared Key), and you're done. Plus, you have great security because the keys change dynamically.