Knowledge Exam 5 (Chapters 13, 14)
Which data transmission rate is defined by the IEEE 802.11b wireless standard? 2 Mbps 10 Mbps 11 Mbps 56 Mbps
11 Mbps The IEEE 802.11b standard defines wireless transmission rates up to 11 Mbps. Wireless network interface cards and wireless access points (also called wireless hubs are wireless routers) will automatically negotiate the best transmission speed up to 11 Mbps based on current network traffic load and the quality of the wireless connection between the client and the access point. The wireless communications are affected by distance, dense physical obstructions, and other electromagnetic interference producing devices.The IEEE 802.11a standard defines wireless transmission rates up to 54 Mbps. The IEEE 802.11g standard defines wireless transmission rates as high as 56 Mbps. The IEEE 802.3 standard defines Ethernet 10BaseT cable-based transmissions of 10 Mbps.
What is the maximum data rate of an ISDN BRI line? 64 Kbps 128 Kbps 256 Kbps 1.544 Mbps
128 Kbps ISDN BRI carries two B channels and one D channel. Each B channel can maintain a throughput of 64 Kbps, for a total of 128 Kbps. The D channel is used for line management, and does not contribute to data throughput.
What type of cordless phone is most likely to interfere with a wireless LAN (WLAN)? 1.7 MHz DECT 2.4 GHz 900 MHz
2.4 GHz 802.11b and 802.11g WLANs operate in the 2.4 GHz band. Additionally, many 802.11n also operate in the 2.4 GHz band (while some 802.11n networks operate in the 5 GHz band). As a result, 2.4 GHz cordless phones can interfere with WLANs operating in that same band of frequencies. Many early cordless phones operated in the 1.7 MHz band. Later cordless phones operated in the 900 MHz band. Fortunately, neither of these bands interferes with any WLAN standard.However, if you need a modern cordless phone that can coexist in an environment with WLAN devices using the 2.4 GHz band, consider the use of Digital Enhanced CordlessTelecommunications (DECT) cordless phones. While the exact frequencies used by DECT cordless phones can vary based on country, DECT cordless phones do not use the 2.4 GHz band. For example, in the United States, DECT cordless phones use frequencies in the range 1.92 GHz - 1.93 GHz.
You are designing a wireless network for a client. Your client needs the network to support a data rate of at least 54 Mbps. In addition, the client already has a wireless telephone system installed that operates in the 2.4 Ghz range.Which 802.11 standard will work best in this kind of a situation? 802.11d 802.11c 802.11g 802.11a 802.11b
802.11a 802.11a is the best choice for this client. While both 802.11a and 802.11g each operate at 54 Mbps, 802.11g operates in the 2.4 Ghz to 2.4835 Ghz range; this will cause interference from the client's wireless phone system.802.11a, on the other hand, operates in the 5.725 Ghz to 5.850 Ghz frequency range; which will not interfere with the phone system. Hence this would be your best standard to choose with the facts given in this question.
A network technician has been tasked with designing a WLAN for a small office. One of the requirements of this design is that it is capable of supporting HD video streaming to multiple devices. Which of the following would be the appropriate wireless technology for this design? 802.11g 802.11ac 802.11b 802.11a
802.11ac IEEE 802.11ac is a wireless networking standard in the 802.11 family (which is marketed under the brand name Wi-Fi), developed in the IEEE Standards Association process, [providing high-throughput wireless local area networks (WLANs) on the 5 GHz band.
You have been contacted by the Eddu Corporation to recommend a wireless Internet solution. The wireless strategy must support a transmission range of 150 feet, use a frequency range of 2.4 Ghz, and provide the highest possible transmission speeds.Which of the following wireless solutions would you recommend? Bluetooth WEP 802.11a 802.11g 802.11b
802.11g Of the technologies listed, only the IEEE 802.11g wireless standard addresses the desired requirements. It is the best choice to satisfy the requirement compared to all answers provided.Bluetooth does operate at the 2.4 Ghz radio frequency range but is limited to a theoretical speed of 1 to 3 Mbps and transmission distances of approximately 33 feet. The 802.11a Wireless standard offers speeds of 54 Mbps but uses the 5 Ghz frequency range. The 802.11b standard used the 2.4 Ghz frequency range but only supports 11 Mbps transfer speeds.
What exists at both ends of a T1 connection? A frame relay A CSU/DSU A digital trunk A multiplexer A router
A CSU/DSU
All of the 802.11 standards for wireless networking support which type of communication path sharing technology? CSMA/CD CSMA/CA Token passing. Polling
CSMA/CA 802.11x standards for wireless networking all support the CSMA/CA (carrier sense multiple access with collision avoidance) type of communication path sharing technology. This CSMA/CA allows for multiple baseband clients to share the same communications mediumPolling is a mechanism where one system is labeled as the primary system. The primary system polls each secondary system in turn to inquire whether they have data to transmit. Token passing is a mechanism that uses a digital pass card. Only the system holding the token is allowed to communicate. CSMA/CD is the technology used by Ethernet.
Which of the following services are available regardless of whether the telephone company network is available? Cable Modem Dialup ISDN DSL
Cable Modem A cable modem is a network connectivity service provided by the cable television service provider. Cable modem operates by adding a bidirectional channel connected directly to the Internet Service Provider (ISP) through cable TV lines. It does not depend on phone lines for the connection. Dial-up refers to Internet access using modems over the telephone company analog network. Integrated Services Digital Network (ISDN) is a method for providing digital connectivity service through the telephone company network. ISDN can combine multiple channels consisting of voice and data simultaneously. DSL is a new a digital service provided by telephone service providers. All of these methods operate over regular phone lines.
Which protocol is used by cable companies? MPLS DOCSIS PSTN SIP
DOCSIS Cable companies use Data Over Cable Service Interface Specification (DOCSIS).
Which of the following Internet connection technologies requires that the location be within a limited distance of the telephone company central office? Wireless. DSL. Cable modem. Satellite
DSL There are several variations of Digital Subscriber Line (DSL) technology available collectively referred to as xDSL. DSL operates over existing telephone company copper wire. DSL operates concurrently with regular voice grade communications by utilizing higher frequencies unused by voice transmissions. One of the consequences of splitting the signal in this manner is that DSL must operate within a fixed distance of telephone company network switching equipment. For this reason DSL is usually only available in major metropolitan areas. The actual distance will vary based upon the form of DSL being implemented, however it ranges between half a mile to 4 ½ miles.A cable modem can be provided as a means of Internet access by the cable television company anywhere within the service area of the cable television company.
You have configured a wireless access point to create a small network. You have configured all necessary parameters. Wireless clients seem to take a long time to find a wireless access point. You want to reduce the time it takes for the clients to connect.What should you do? Change the channel on the access point to a lower number. Create a wireless profile on the client. Decrease the beacon interval. Enable SSID broadcast
Decrease the beacon interval. A beacon is a frame that is sent out periodically by the access point. The beacon announces the access point and the characteristics of the network (such as the SSID, supported speeds, and the signaling method used.). To improve access times you could decrease the beacon interval.As long as clients are configured with the SSID, they will be able to locate access points even if the SSID is not being broadcast in the beacon. The beacon is still sent to announce the access point. Adding the SSID to the beacon will not change how often the beacon is being broadcast.
A wireless LAN (WLAN) containing at least two access points (APs) is known as what type of WLAN? ESS SSID IBSS BSS
ESS An Independent Basic Service Set (IBSS) WLAN can be created without the use of an access point (AP). This type of ad hoc WLAN can be useful for temporary connections between wireless devices. For example, you might temporarily interconnect two laptop computers to transfer a few files.A Basic Service Set (BSS) WLAN uses a single AP. BSS WLANs are said to run in infrastructure mode (as opposed to ad hoc mode), because wireless clients connect to an AP, which is typically connected to a wired network infrastructure.An Extended Service Set (ESS) WLAN is a WLAN containing two or more APs. Like a BSS WLAN, ESS WLANs operate in infrastructure mode. This is the correct answer to this questionA Service Set Identifier (SSID) can be thought of as the name of a WLAN. Often, an AP will broadcast the name of a WLAN's SSID, thus allowing wireless devices to see that the WLAN is available.
Which of the following wireless network terms or concepts graphically displays wireless signal strength within an area? Device density Roaming LWAPP VLAN pooling Wireless Bridge Heat map Goodput
Heat map
Which of the following wireless network terms or concepts is used by Cisco wireless equipment to route frames back and forth between the wireless network and the wired LAN? Device density Roaming LWAPP VLAN pooling Wireless Bridge Heat map Goodput
LWAPP The Lightweight Access Point Protocol (LWAPP) is used by Cisco wireless equipment to route frames back and forth between the wireless network and the wired LAN
A company is experiencing very slow network speeds of 54Mbps. A technician has been hired to perform an assessment on the existing wireless network. The technician has recommended an 802.11n network infrastructure. Which of the following allows 802.11n to reach higher speeds? MU-MIMO LWAPP PoE MIMO
MIMO 802.11n, is a wireless networking standard that uses multiple antennas to increase data rates. Its purpose is to improve network throughput over the two previous standards-802.11a and 802.11g-with a significant increase in the maximum net data rate from 54 Mbit/s to 600 Mbit/s, with the use of four spatial streams at a channel width of 40 MHz. 802.11n standardized support for multiple-input multiple-output, frame aggregation, and security improvements, among other features. It can be used in the 2.4 GHz or 5 GHz frequency bands.MIMO is a technology that uses multiple antennas to coherently resolve more information than possible using a single antenna. One way it provides this is through Spatial Division Multiplexing (SDM), which spatially multiplexes multiple independent data streams, transferred simultaneously within one spectral channel of bandwidth. MIMO SDM can significantly increase data throughput as the number of resolved spatial data streams is increased. Each spatial stream requires a discrete antenna at both the transmitter and the receiver. In addition, MIMO technology requires a separate radio-frequency chain and analog-to-digital converter for each MIMO antenna, making it more expensive to implement than non-MIMO systems.The MIMO architecture, together with wider-bandwidth channels, offers increased physical transfer rate over 802.11a (5 GHz) and 802.11g (2.4 GHz).
You are setting up a wireless hotspot in a local coffee shop. For best results, you want to disperse the radio signals evenly throughout the coffee shop. Which of the following types of antennas would you use on the access point to provide a 360 degree disbursed wave platform? Omni-directional Directional Multi-directional Multi-point Uni-directional.
Omni-directional An Omni-directional antenna provides a 360° disbursed wave pattern. In this configuration, signals are disbursed evenly in all directions making it well suited for environments such as coffee shops where clients are accessing the network from various locations. A dispersed wireless signal is weaker and therefore is restricted to shorter signal distances.A directional wireless antenna focuses a signal in a particular direction. The focus signal allows for greater transmission distances and a stronger signal. Directional antennas are sometimes used to establish a wireless point-to-point connection where greater transmission distances are often required.
You have been hired to troubleshoot a wireless connectivity issue for two separate networks located within a close proximity. For whatever reason they cannot connect. Both networks use a WAP from the same manufacturer and all settings, with the exception of SSID's remain configured to the default.Which of the following might you suspect as the cause of the connectivity problems? The SSIDs of the two server systems match WEP overlap The SSIDs of the two client system match Overlapping channels Crosstalk between the RF signals
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 WAP. The solution to the problem 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 would not be a problem.
You are configuring a wireless network with two wireless access points. Both access points connect to the same wired network. You want wireless users to be able to connect to either access point, and to be able to roam between the two access points. How should you configure the access points? Same SSID, different channel Same SSID, same channel Different SSID, same channel Different SSID, different channel
Same SSID, different channel When configuring multiple access points as part of the same extended service set (ESS) configure both access points with the same Service Set Identifier (SSID). The SSID is like a network name, and groups wireless devices together into the same logical network. All devices, including wireless clients, use the same SSID.Wireless access points that are in the same area should use different channels. If the channels are the same or overlap, devices connected to one access point might interfere with devices connected to the other access point in locations where the signal overlaps.
What encryption method is used by WPA for wireless networks? AES IPSec 802.1x TKIP WEP
TKIP WPA uses TKIP for its encryption. TKIP uses rotating encryption keys for added security over WEP.AES encryption is used with WPA2. AES requires specialized hardware that might not be available on a device that only supports WPA. WEP is a security method for wireless networks that provides encryption through the use of a shared encryption key (the WEP key).IPSec is an encryption method that is used for VPN tunneling; while it can be used on a wireless network, it is used in addition to encryption provided by either WEP, WPA, or WPA2. 802.1x is an authentication method for wired and wireless networks.
A user on your network has been moved to another office down the hall. After the move she calls you complaining that she has only occasional network access through her wireless connection. Which of the following is most likely cause of the problem? The client system has moved too far from the access point. An SSID mismatch between the client and the server. The encryption level has been erroneously sent back to the default setting. An SSID mismatch between the client and the WAP The client has incorrect WEP settings.
The client system has moved too far from the access point. In this case, the wireless client system has had no problems accessing the wireless access point until the move to the new office. In some cases moving a system will cause signal loss either from the increased distance away from the WAP or from unexpected interference by such things as concrete walls or steel doors. There are several ways to correct the problem including reducing the physical distance to the client, using a wireless amplifier, upgrading the antennas on the wireless devices or adding another WAP to the infrastructure.Because the client could previously access the WAP and still has occasional access, it is likely the move was the cause of the problem and not any configuration setting on the client system.
What purposes does a wireless site survey serve? Select two answers only. To identify the recommended 100° separation angle for alternating access points. To identify the coverage area and preferred placement of access points. To document existing Infrared traffic in the 5.4 Ghz spectrum. To identify existing or potential sources of interference
To identify the coverage area and preferred placement of access points. To identify existing or potential sources of interference Wireless site surveys provide layout and design parameters for access point coverage and placement. A Site survey can also identify rogue access points and other forms of interference that reduce security and prevent the proper operation of authorized network devices. Radio Frequency Spectrum and Protocol analyzers are used in order to conduct the surveys.
Which of the following wireless network terms or concepts automatically partitions a single broadcast domain into multiple VLANs? Device density Roaming LWAPP VLAN pooling Wireless Bridge Heat map Goodput
VLAN pooling
Which two of the following are wireless broadband technologies? WiMAX ISDN ATM HSPA+
WiMAX HSPA+ Worldwide Interoperability for Microwave Access (WiMAX) provides wireless broadband access to fixed locations (as an alternative to technologies such as DSL) and mobile devices. Depending on the WiMAX service provider, WiMAX coverage areas could encompass entire cities or small countries.Like WiMAX, Evolved High-Speed Packet Access (HSPA+) is a technology offering wireless broadband service. The maximum data rate for HSPA+ is 84 Mbps.Asynchronous Transfer Mode (ATM) and Integrated Services Digital Network (ISDN), however, are wired broadband technologies.
Frame Relay is an example of what WAN connection type? packet switched cell switched dedicated leased line circuit switched
packet switched A packet switched connection is similar to a dedicated leased line, because most packet switched networks are always on. However, unlike a dedicated leased line, packet switched connections allow multiple customers to share a service provider's bandwidth.Frame Relay is an example of a packet switched connection. Asynchronous Transfer Mode (ATM) is often categorized as a packet switched connection. However, to be technically accurate, ATM is a cell switched connection, because ATM uses fixed-length (that is, 53 Byte) cells, as opposed to variable-length frames.A dedicated leased line is a logical connection interconnecting two sites. This logical connection might physically connect through a service provider's facility or a telephone company's central office. The expense of a dedicated leased line is typically higher than other WAN technologies offering similar data rates, because with a dedicated leased line a customer does not have to share bandwidth with other customers. A T1 circuit is an example of a dedicated leased line technology commonly found in North America.A circuit switched connection is a connection that is brought up on as as-needed basis. In fact, a circuit switched connection is analogous to phone call, where you dial a number, and a connection is established based on the number you dial. As an example, Integrated Services Digital Network (ISDN) can operate as a circuit switched connection, bringing up a virtual circuit on-demand.