Network + Ch 4-6 Exam 2 – Flashcards
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A _______ is a device that retransmits a digital signal in its original form, extending the length of a segment.
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Repeater
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Which of the following options is not a likely source of electromagnetic interference?
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fiber optic cables
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A ______ is a voltage, frequency, pulse, or phase change in a analog transmission.
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symbol
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A ________ allows for an MTU as high as 9198 bytes.
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Jumbo frame
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What 802.11 frame type is involved in association and reassociation, including probing and beacon frames?
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management frames
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A character encoding system consisting of 128 characters.
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ASCII
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A multiplexing technique used over single-mode or multimode fiber-optic cable in which each signal is assigned a different wavelength for its carrier wave.
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DWDM
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A term used to refer to a type of twisted-pair cable. All of the category cables fall under the TIA/EIA 568 standard.
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Cat (Category)
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An unwanted connection, such as when exposed wires touch each other.
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short circuit
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Physical layer standard for networks that specifies 1-Gbps transmission over fiber-optic cable using based band transmission, relying on 1300 nanometer wavelengths.
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1000Based-LX
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Crossed-talk measured at the far end of the cable from the signal source.
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Far end cross-talk (FEXT)
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The distance between corresponding points on a wave's cycle, expressed in meters or feet.
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wavelength
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A Physical layer standard for network that achieves 1 Gbps over Cat 6 or better cabling using only two pairs of wires.
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1000Based-TX
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The amount of data that a medium transmits during a given period of time.
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Throughput
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A form of transmission that allows multiple signals to travel simultaneously over one medium.
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Multiplexing
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DC to AC
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Inverter
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AC to DC
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rectifer
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Complete power loss
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Blackout
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Copper-based cable that consists of one or more insulated twisted-pair wires encased in a plastic sheath.
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UTP
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Transmits data via pulsing light sent from a laser or led
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fiber-optic cable
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Copper-based cable containing twisted-wire pairs that are not only individually insulated, but also surrounded by a shielding made of a metallic substance such as foil.
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STP
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Momentary decrease in voltage, also known as SAG
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Brownout
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Multipath signaling is a significant cause of fading. True or False
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True
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What signal propagation phenomena causes a wireless signal to split into secondary waves when it encounters an obstruction?
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Diffraction
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The radius of the maximum arch into which you can loop a cable without impairing data transmission is known as what option below?
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bend radius
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Which 802.11 technology is the first Wi-Fi standard to approach gigabit Ethernet capabilities, and operates on the 5 GHz band?
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802.11ac
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A device that is responsible for modulating digital signals into analog signals, and demodulating analog signals into digital signals at the receiving end, is known as?
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A modem
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A device that changes the form of electrical energy in some way. Four common types are inverter, rectifier, transformer, and voltage regulator.
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Power Converter
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The industry-standard unit for measuring rack height. Standard racks are 42U tall—about 6 feet.
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Rack Unit
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The portion of an Ethernet network in which collisions could occur if two nodes transmit data at the same time.
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Collision Domain
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The flow of electrical power at a steady rate in only one direction.
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DC - direct current
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In a chassis, the path along which air from a cool air source is conducted, past equipment to cool it, and then out of the rack. Typically, air moves from front to back.
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Airflow
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The field in a frame responsible for ensuring that data carried by the frame arrives intact. It uses an algorithm, such as CRC, to accomplish this verification.
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FCS Frame Check Sequence
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A device that converts DC electrical energy to AC electrical energy. Better inverters will also condition the power, which helps protect sensitive electronic equipment from power fluctuations.
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Inverter
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A device that maintains a constant voltage level for either AC or DC electrical energy.
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Voltage Regulator
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Electrical power flow on a circuit that continually switches direction.
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AC - alternating current
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A specialized storage device or group of storage devices that provides centralized fault-tolerant data storage for a network.
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NAS - networked attached storage
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Frequencies used to convey speech over telephone lines fall between what two frequencies below?
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300Hz 3.3 KHz
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The act of driving around an area while running a laptop configured to detect and capture wireless data transmissions.
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war driving
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A method used by wireless stations to detect the presence of an access point. Using this method, the station issues a probe to each channel in its frequency range and waits for the access point to respond.
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active scanning
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The use of chalk to draw symbols on a sidewalk or wall within range of an access point. The symbols, patterned after marks that hobos devised to indicate hospitable places for food or rest, indicate the access point's SSID and whether it's secured.
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war chalking
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The throughput experienced at the application level, such as the quality of a video feed or the speed of a Web page loading in the browser.
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goodput
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In the context of wireless signal propagation, the phenomenon that occurs when an electromagnetic wave encounters an obstruction and splits into secondary waves. The secondary waves continue to propagate in the direction in which they were split.
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diffraction
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An 802.11 frame type that is responsible for carrying data between stations. Two other frame types include management frames, which are involved in association and reassociation, and control frames, which are related to medium access and data delivery.
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data frame
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A type of antenna that issues and receives wireless signals with equal strength and clarity in all directions. This type of antenna is used when many different receivers must be able to pick up the signal, or when the receiver's location is highly mobile.
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Omnidirectional antenna
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A type of antenna that issues wireless signals along a single direction, or path. Also called a directional antenna.
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unidirectional antenna
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A security exploit in which a WPS PIN is discovered by means of a brute force attack, giving the attacker access to the network's WPA2 key. The PIN feature in WPS should be disabled if possible.
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WPS attack
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An attack in which a Bluetooth connection is used to download data from a device without the owner's permission.
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Bluesnarfing
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Where is a demarc located in relation to the structured cabling of an enterprise environment?
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In the MDF (main distribution frame)
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What cable type comes in two different modes, single and multimode?
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Fiber Optic
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Because digital signals do not depend on amplitude or frequency differences to communicate information, they are more vulnerable to EMI noise. T or F
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False
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A NIC card cannot determine whether the frames it transmits and receives are using IP packets or a different layer 3 protocol, because the NIC does not operate higher than Layer 2 of the OSI model. T or F
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True
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The TIA/EIA standard for wall jacks in a work area require that at least one outlet be provided for data and one for voice. T or F
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True
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Phone companies make use of what type of multiplexing in order to allow for phone services and DSL services over the same line?
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FDM Frequency Division Multiplexing
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Which method of transmission allows signals to travel in both directions over a medium but in only one direction at a time?
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half duplex
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What is the maximum supported throughput of a CAT6 cable?
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10 Gbps
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What two options below are two different types of attacks against Bluetooth connections that can be used to send unsolicited data, or download data without permission?
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Bluesnarfing Bluejacking
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Unlike wired signals, wireless signals originate from electrical current traveling along a capacitor. T or F
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False
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Select the two Transport Layer protocols that are used by SANs:
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Fibre Channel iSCSI
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What type of power converter changes the voltage of an AC current, such as when power over the main line from an electric company is changed before being delivered to a home?
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Transformer
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Ideally, stations must remain within what range of an access point in order to maintain optimal transmission speeds?
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300 feet
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An electronic device that increases the voltage, or strength, of analog signals
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Amplifier
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A device that regenerates a digital signal in it's original form
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Repeater
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accepts and analyzes the return signal, and based on its condition and the amount of time the signal took to return, determines cable imperfections
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TDR (Time Domain Reflectometer)
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Progress of a wave over time in relationship to a fixed point
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Phase
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pulses of precise, positive voltages and zero voltages
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Digital Signal
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modifies analog signals to make them suitable for carrying data over a communication path
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Data Modulation
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What two connector types are typically used to terminate RG-6 and RG-59 cables?
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f-connectors BNC
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_______ are highly scalable and have a very high fault tolerance, massive storage capabilities, and fast data access.
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SANs
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What is the maximum supported throughput and bandwidth / signal rate of Cat 5e?
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100Mbps 100MHz
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Standard PoE devices must be provided with how much power in order to function?
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15.4 watts
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Select the maximum allowable distances for horizontal wiring for a span that connects a data jack on a wall to a data closet, and for a span that connects a workstation to the data jack, respectively:
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100m
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A serial cable with an RJ-45 connector is capable of being used through an RJ-45 Ethernet port. T or F
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False
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One watt is equal to how many volt-amps?
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1.4
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Which type of multiplexing is defined by wavelength instead of frequency?
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CWDM
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Select the component of enterprise level structured cabling that serves as the location where an incoming network interface enters a building and connects with the building's backbone cabling:
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Entrance Facility
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In an 802.11 data frame, what is the size of the frame check sequence field?
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6 bytes
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What is the industry standard for rack height in rack units?
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42U
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The room where the _________________ is located is called the data closet.
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MDF (main distribution frame)
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A power fluctuation that results in a temporary dimming of lights is known as a blackout. T or F
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False
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The most common multiplexing technology used in conjunction with fiber optics is which option below?
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WDM
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NFC tags are very expensive and cannot be purchased blank, requiring them to be pre-loaded. T or F
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False
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In IEEE terminology, a group of stations that share an access point are said to be part of what option below?
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Basic Service Set
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At what layer of the OSI model do the 802.11 standards vary?
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Physical Layer
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Select below the band that is not one of the four frequency bands used in the 5 GHz range for wireless LANs:
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5.9 GHz
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What is the maximum distance for 10GBase-ER and 10GBase-EW on a segment of single mode fiber?
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40Km
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All wireless signals are carried through the air by electromagnetic waves. T or F
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True
