9.3.9 Wireless Network Design
You are designing a wireless network for a client. Your client needs the network to support a data rate of at least 150 Mbps. In addition, the client already has a wireless telephone system installed that operates at 2.4 GHz. Which 802.11 standard works best in this situation? - 802.11g - 802.11a - 802.11n - 802.11b
802.11n 802.11n is the best choice for this client. 802.11b and 802.11g both operate in the 2.4 GHz to 2.4835 GHz range, which will cause interference with the client's wireless phone system. 802.11a operates in the 5.725 GHz to 5.850 GHz frequency range. While this won't interfere with the phone system, the maximum speed is limited to 54 Mbps.
Which of the following uses a 2.4 GHz ISM band, has fast transmission rates, and has been used for applications like geocaching and health monitors? - Z-Wave - Ant+ - NFC - 802.11ac
Ant+ Ant+ is generally used to monitor sensor data. It uses a 2.4 GHz ISM band, has fast transmission rates, and has been used for applications like geocaching and health monitors. The Z-Wave protocol is found in the home security and automation market and uses only a mesh topology. Each attached device acts as a repeater and increases the network strength. Z-Wave has a low data transfer rate. NFC (Near Field Communication) is common with mobile pay solutions and connections like Bluetooth, but NFC has to be within 10 cm or 4 inches from another device to connect. 802.11ac is a wireless networking standard that offers high-speed data transfer.
Which of the following should you include in your site survey kit? - A GPS - Mounting brackets - A tall ladder - A network bridge
A tall ladder A site survey kit should include: Two access points (APs). Bring access points to each location to test the signal quality and to identify the node density required in each area. Two laptops with a network performance measurement utility (such as Iperf) installed. This allows you to evaluate the network throughput at each location. A tall ladder so you can test each AP at its height or close to its height. Log the location's GPS coordinates. Use digital photos to document the location and its surrounding environment. During a site survey, you don't physically install the access points. A network bridge connects different network segments. It's not included in a site survey kit.
You are concerned that wireless access points might have been deployed within your organization without authorization. What should you do? (Select two. Each response is a complete solution.) - Check the MAC addresses of devices that are connected to your wired switch. - Implement an intrusion detection system (IDS). - Conduct a site survey. - Implement an intrusion prevention system (IPS). - Implement a network access control (NAC) solution.
Check the MAC addresses of devices that are connected to your wired switch. Conduct a site survey. A rogue host is an unauthorized system that has connected to a wireless network. It could be an unauthorized wireless device or even an unauthorized wireless access point that someone connected to a wired network jack. Rogue hosts can be benign or malicious in nature. Either way, rogue hosts represent a security risk, and you should detect and subsequently remove them immediately. Four commonly used techniques for detecting rogue hosts include: Use site survey tools to identify hosts and APs. Check connected MAC addresses to identify unauthorized hosts. Conduct an RF noise analysis to detect a malicious rogue AP that's using jamming. Analyze wireless traffic to identify rogue hosts. Using an IDS or an IPS would not be effective, as these devices are designed to protect networks from perimeter attacks. Rogue APs are internal threats. You can use a NAC solution to remediate clients that connect to the network, but this solution doesn't detect rogue APs.
Match each wireless term or concept on the left with its associated description on the right. Each term may be used more than once. (Not all descriptions have a matching term.) Checks channel utilization and identifies sources of RF inference. Compares the Wi-Fi signal level to the level of background radio signals. Identifies how strong a radio signal is at the receiver. Signal-to-noise ratio Spectrum analysis Received signal level
Checks channel utilization and identifies sources of RF inference. - Signal-to-noise ratio Compares the Wi-Fi signal level to the level of background radio signals. - Spectrum analysis Identifies how strong a radio signal is at the receiver. - Received signal level
You have been hired to design a wireless network for a SOHO environment. You are currently in the process of gathering network requirements from management. Which of the following questions should you ask? (Select three.) - Which type of data will be transmitted on the network? - What are the zoning and permit requirements? - Where can network hardware be mounted in the building? - How many devices will need to be supported? - Is the size of the business expected to grow in the future? - Is there future construction that might affect or disrupt the RF signals? - Are there microwaves or cordless phones that can cause interference?
How many devices will need to be supported? Which type of data will be transmitted on the network? Is the size of the business expected to grow in the future? The first thing you do when designing a wireless network is gather network requirements. Meet with all stakeholders and decision-makers to discuss the implementations and gather detailed information. For example, you should: Identify the intended use of the wireless network. Identify the location of wireless service areas. Anticipate the number of wireless devices that need to be supported in each area. Discuss future network needs so that you can plan for expansion. Discuss data encryption and network security requirements. You should consider mounting points, interference, zoning and permit requirements, and future construction during the network design phase. This happens after all requirements have been gathered.
Which of the following purposes do wireless site surveys fulfill? (Select two.) - Identify the coverage area and preferred placement of access points. - - Identify the recommended 100 degree separation angle for alternating access points. - Document existing infrared traffic in the 5.4 GHz spectrum. - Determine the amount of bandwidth required in various locations.
Identify the coverage area and preferred placement of access points. Identify existing or potential sources of interference. Wireless site surveys provide layout and design parameters for access point coverage and placement. Site surveys can also identify rogue access points and other forms of interference that reduce security and prevent the proper operation of authorized network devices. You use radio frequency spectrum and protocol analyzers to conduct these surveys. As part of bandwidth planning, you determine the amount of bandwidth required in various locations.
Which of the following does an SNR higher than 1:1 indicate? - No signal - More noise than signal - More signal than noise - No noise
More signal than noise An SNR higher than 1:1 indicates more signal than noise, which is desirable.
You have been hired to troubleshoot a wireless connectivity issue for two separate networks located within a close proximity. Both networks use a WAP from the same manufacturer, and all settings (with the exception of SSIDs) remain configured to their defaults. Which of the following might you suspect is the cause of the connectivity problems? - There is crosstalk between the RF signals. - There are overlapping channels - The two server systems' SSIDs match. - The two client systems' SSIDs match. - There is WEP overlap.
There are overlapping channels Overlapping wireless networks should use different channels to ensure that they do not conflict with each other. In this case, each WAP is using the default channel, which by default, is the same for each one. The solution would be to configure different channels for each access point. To configure client connectivity, the wireless client and the access point must share the same SSID, channel, and WEP encryption strength. In this case, the SSIDs were changed for each station, so they are not the problem.
Which protocol is well known for its use in the home security and home automation industry, uses a mesh topology, makes devices act as repeaters, and has a low data transfer rate? - NFC - 802.11ac - Ant+ - Z-Wave
Z-Wave The Z-Wave protocol is mostly found in the home security and automation market and uses only a mesh topology. Each attached device acts as a repeater and increases the network strength. Z-Wave has a low data transfer rate. Ant+ uses a mesh topology. However, Ant+ is generally used to monitor sensor data. NFC is common with mobile pay solutions and connections like Bluetooth, but NFC has to be several inches from another device to connect. 802.11ac is a wireless networking standard that offers high-speed data transfer.