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166 Cards in this Set

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1 gigabit per second (Gbps)
1,000,000,000 bits per second.
1 kilobit per second (Kbps)
1000 bits per second.
1 megabit per second (1Mbps)
1,000,000 per second.
1 terabit per second (Tbps)
1,000,000,000,000 bits per second.
10BASE-F
A Physical layer standard for achieving 10-Mbps throughput over mulitmode fiber-optic cable. Three different kinds of it exist. All require two strands of multimode fiber in which one strand is used for data transmission and one strand is used for reception, making this a full-duplex technology.
10BASE-FL
THE most popular version of the 10BASE-F standard. It is designed to connect workstations to a LAN or two repeatersand can take advantage of fiber-optic repeating technology to reach its maximum segment length of 2000 meters. It makes use of star topology with its repeaters connected through a bus.
10BASE-T
A Physical layer standard for networks that specifies baseband transmission, twisted pair media, and 10-Mbps throughput. These networks have a maximum segment length of 100 meters and rely on star topology.
10GBASE-ER
A Physical layer standard for achieving 10-Gbps data tranmission over single-mode, fiber-optic cable. The ER stands for Extended Reach. This standard specifies a star topology and segment lenghts up to 40 kilometers.
10GBASE-LR
A Physical layer standard for achieving 10-Gbps data tranmission over single-mode, fiber-optic cable using wavelengths of 1310 nanometers. LR stands for Long Reach. It specifies a star topology and segment lengths up to 10 kilometers.
10GBASE-SR
A Physical layer standard for achieving 10-Gbps data tranmission over single-mode, fiber-optic cable usinge wavelengths of 850 nanometers. The maximum segment length is 300 meters, depending on the fiber core diameter and modal bandwidth used.
100BASE-FX
A Physical layer standard for networks that specifies baseband transmission, multimode fiber cabling, and 100-Mbps throughput. It may also be called fast ethernet.
100BASE-CX
A Physical layer standard for achieving 1-Gbps throughput over twinaxial copper wire. Its segments are limited to 25 meters, and are useful mainly to connect devices like servers and switches.
100BASE-TX
A type of 100BASE-T network that uses two wire pairs in a twisted-pair cabling, and 100-Mbps throughput. It is capable of full-duplex transmission and requires CAT-5 or higher twisted-pair media.
1000BASE-LX
A Physical layer standard for networks that specifies 1-Gbps transmission over fiber-optic cable using baseband transmission. It runs of multimode fiber. Its maximum segment length is 550 meters. The SX represents its reliance on short wavelengths of 850 nanometers. It can use one repeater.
1000BASE-T
A Physical layer standard for achieving 1 Gbps over UTP. It achieves its higher throughput by using all four pairs of wires in a CAT 5 or higher twisted pair cable to both transmit and receive signals. It also uses a different data encoding scheme than that used by other UTP Physical layer specifications.
2.4 GHz band
The range of radiofrequencies from 2.4 to 2.4835 GHz. The 2.4 GHz band is often used for wireless network transmissions.
5-4-3 rule
A guideline for 10-Mbps Ethernet networks stating that between two communicating nodes, the network cannot contain more than five network segments, connected by four, repeating devices, and more than three of the segments may be populated.
802.3ab
The IEEE standard that describes 100BASE-T, a 1-Gigabit Ethernet technology that runs over four pairs of CAT 5 or better cable.
802.3ae
The IEEE standard that describes a 10-Gigabit Ethernet technologies, including 10GBASE-SR, 10GBASE-ER, and 10GABSE-LR.
802.3u
The IEEE standard that describes Fast Ethernet technologies, including 100BASE-TX, 100BASE-T4, and 100BASE-FX.
802.3z
The IEEE standard that describes 1000Base (or 1-Gigabit)Ethernet technologies, including 1000Base-LX, 1000BASE-SX, and 1000BASE-CX.
ad-hoc
A type of wireless LAN in which stations communicate directly with each other (rather than using an access point).
AM (Amplitude Modulation)
A modulation technique in which the amplitude of the carrier signal is modified by the application of a data signal.
amplifier
A device that boosts, or strengthens an analog signal.
amplitude
A measure of a singnals strength.
analog
A signal that uses variable voltage to create continuous waves, resulting in an inexact transmission.
AP (access point)
A device used on a wireless LANs that transmits and receives wireless signals to an from multiple nodes and retransmits them to the rest of the network segment. Access points can connect to a group of nodes with a network or two networks with each other. They may use directional or omni-directional antennas.
attenuation
The extent to which a signal has weakened after traveling a given distance.
bandwidth
A measure of the difference between the highest and lowest frequencies that a medium can transmit.
baseband
A form of transmission in which digital signals are sent through direct current pulses applied to a wire. The direct current requires exclusive use of the wire's capacity, so these systems can transmit only one signal, or one channel at a time. Every device on this system shares a single channel.
bend radius
The radius of the maximum arc into which you can loop a cable before you will cause data transmission errors. Generally, a twisted-pair cable's bend-raius is equal to or greater than four times the diameter of the cable.
binary
A system founded on using 1s and 0s to encode information.
bit (binary digital)
A bit equals a single pulse in the digital encoding system. It may have only one of two values; 0 or 1.
braiding
A braided metal shielding used to insulate some types of coaxial cable.
broadband
A form of transmission in which signals are modulated as radiofrequency analog pulses with different frequency ranges. Unlike baseband, this technology does not involve binary encoding. The use of multiple frequencies enables a this system to operate over several channels and, therefore carry much more data than a baseband system.
byte
Eight bits of information. In a digital signaling system, broadly speaking, one byte carries one piece of information.
cable modem
A device that modulates and demodulates the broadband cable signals
cable plant
The hardware that constitutes the enterprise-wide cabling system.
CAT
Abbreviation for the word "category" when describing a type of twisted-pair cable. For example, Category 3 unshielded twisted-paircable may also be called CAT3.
CAT 3 (category 3)
A form of UTP that contains four wire pairs and can support up to 10 Mbps, with a possible bandwidth of 16Mhz. It has typically been used for 10-Mbps Ehternet or 4-Mbps Token Ring networks. Network administrators are gradually replacing this type with CAT 5 to accomodate higher throughput. It is less expensive than CAT 5.
CAT 4 (Category 4)
A form of UTP that contains four wire pairs and can support up to 16-Mbps throughput. It may be used for 16-Mbps Token Ring or 10-Mbps Ethernet networks. It is guaranteed for data transmission p to 20 MHz and provides more protection against crosstalk and attenuation than CAT 1, 2 or 3.
CAT 5(Category 5)
A form of UTP that contains four wire pairs and supports up to 100-Mbps throughput and a 100MHz signal rate.
CAT 5e (Category 5 enchanced)
A higher-grade version of CAT 5 wiring that contains high quality copper, offers a high twist ratio, and used advanced methods for reducing cross talk.
CAT 6 (Category 6)
A twisted pair cable that contains four wire pairs, each wrapped in foil insulation. Additional foil insulation covers the bundle of wire pair, and a fire resistant plastic sheath covers the second foil layer.
CAT 6e (Category 6 enhanced)
A higher-grade version of CAT 6 wiring that further reduces attenuation and crosstalk and allows for potentially exceeding traditional network segment length limits. It is capable of a 550-MHz signaling rate and can reliably transmit data at multi-Gigabit per second rates.
channel
A distinct communication path between two or more nodes. They may be seperated by either logically (as in mutliplexing) or physically (as in using seperate wires)
cladding
The glass or plastic shield around the core of a fiber-optic cable. It reflects light back to the core in patterns that vary depending on the transmission mode. This reflection allows fiber to bend around corners withouth impairing the light-based signal.
coaxial cable
A type of cable that consists of a central copper core surrounded by an insulator, a braided metal shielding, called braiding, and an outer cover, called the sheath or jacket. It was the foundation for Ethernet networks in the 1980s and remained a popular transmission medium for many years.
conduit
The pipeline used to contain and protect cabling. Conduit is ususally made from metal.
connectors
The pieces of hardware that connect the wire to the network device.
core
The central component of a cable designed to carry a signal.
crossover cable
A twisted-pair patch cable in which the termination locations of the transmit and receive wires on one end of the cable are reversed.
crosstalk
A type of interference cause by signals traveling on nearby wire pairs.
demarcation point (demarc)
The point of division between a telecommunications service carrier's network and a building internal network.
demultiplexer (demux)
A device that seperates multiplexed signals once they are received and regenerates them in their original form.
diffraction
In the context of wireless signal propogation, the phenomenon that occurs when an electromagnetic wave ecounters an obstruction and splits into secondary waves. The secondary waves continue to propogate in the direction in which they were split. Basically, the signal bends around obstacles.
digital
As opposed to analog signals, these type of signals are composed of pulses that can have a value of only 1 or 0.
directional antenna
A type of antenna that issues wireless signals along a single direction, or path.
DSSS (direct sequence spread spectrum)
A transmission technique in which a signal's bits are distributed over an entire frequency band at once. Each bit is coded so that the receiver can reassemble the original signal upon receiving the bits.
DWDM (dense wavelength division multiplexing)
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. Little space exists between carrier waves, in order to achieve extraordinary high capacity.
EMI(electromagnetic interference)
A type of interference that may be cause by motors, power lines, televisions, copiers, fluorescent lights, or other sources of electrical activity.
F-type connector
A connector used to terminate coaxial cable used for transmitting television and broadband cable signals.
fading
A change in wireless signal's strength as a result of some of the electromagnetic energy being scattered, reflected, or diffracted after being issued by the transmitter.
Fast Ethernet
A type of Ethernet network that is capable of 100-Mbps throughput 100BASET and 100BASE-FX are both example of Fast Ethernet.
fault tolerance
The capability for a component or system to continue functioning despite damage or malfunction.
ferrule
A short tube within a fiber-optic cable connector that encircles the fiber strand and keeps it properly aligned.
FHSS (frequency hopping spread spectrum)
A wireless signaling technique in which a signal jump between several different frequencies within a band in a synchronization pattern known to the channel's receiver and transmitter.
fiber-optic cable
A form of cable that contains one or several glass or plastic fibers in its core. Data is transmitted via pulsing light sent from a laser or light-emitting diode (LED) through the central fiber (or fibers). Fiber-optic cables offer significantly higher throughput than copper-based cables. They may be single-mode or multimode and typically use wave-division multiplexing to carry multiple signals.
fixed
A type of wireless system in which the locations of the transmitter and receiver are static. The transmitting antenna focuses its energy directly toward the receiving antenna. This results in a point-to-point link.
FM (frequency modulation)
A method of data modulation in which the frequency of the carrier signal is modified by the application of the data signal.
frequency
The number of times that a signal's amplitude changes over a fixed period of time, expressed in cycles per second, or hertz.
full-duplex
A type of transmission in which signals may travel in both directions over a medium simultaneously.
Gigabit Ehternet
A type Ethernet network is capable of 1000Mbps or 1Gbps throughput. Examples: 1000BASE-T and 1000BASE-CX.
half-duplex
A type of transmission in which signals may travel in both directions over a medium, but only in one direction at a time.
hertz (Hz)
A measure of frequency equivalent to the number of amplitude cycles per second.
impedance
The resistance that contributes to controlling an electrical signal. It is measured in ohms.
infared (IR)
A type of data transmission in which infared light signals are used to transmit data through space, similar to the way a television remote control sends signals across the room. Networks may use two types of this technology: direct or indirect.
Infrastructure WLAN
A type of WLAN in which stations communicate with an access point and not directly with each other.
latency
The delay between the transmission of a signal and its receipt.
LC (Local Connector)
A connector used with single- mode or multi-mode fiber-optic cable.
LOS (line-of-sight)
A wireless signal or path that travels directly in a straight line from its transmitter to its intended receiver.
media converters
A device that enables networks or segments using different media to interconnect and exchange signals.
MMF (multimode fiber)
A type of fiber-optic cable that contains a core with a diameter between 50 and 100 microns, through which many pulses of light generated by a light emitting diode (LED) travel at different signals.
mobile
A type of wireless system in which the receiver can be located anywhere within the transmitters range. This allows the reciever to roam from place to place while continuing to pick up its signal.
modal bandwidth
A measure of the highest frequency of signal a multimode fiber-optic cable can support over a specific distance. It is measured in MHz-km.
modem
a device that modulates analog signals at the transmitting end for transmission over telephone lines, and demodulates digital signals int to analog signals at the receiving end.
modulation
A technique for formatting signals in which one property of a simple carrier wave is modified by the addition of a data signal during transmission.
MT-RJ (Mechanical Transfer Reegisterd Jack)
A connector used with single-mode or multi-mode fiber-optic cable.
multipath
The characteristic of wireless signals that follow a number of different path to their destination (for example, because of reflection, diffraction, and scattering).
mutliplexer (mux)
A device that seperates a medium into multiple channels and isssues signals to each of those subchannels.
multiplexing
A form of transmission that allows multiple signals to travel simultaneously.
narrowband
A type of wireless transmission in which signals travel over a single frequency or with a specified frequency range.
noise
The unwanted signals, or interference, form sources near network cabling, such as electrical motors, power lines and radar.
omnidirectional antenna
A type of antenna that issues and recieves 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.
optical loss
The degradation of a light signal on a fiber-optic network.
overhead
The nondata information that must accompany data in order for a signal to be properly routed and interpreted by the network.
patch cable
A relatively short section (usually between 3 and 25 feet) of cabling with connectors on both ends.
patch panel
A wall-mounted panel of data receptors into which cross-connect patch cables from the punch-down block are inserted.
PDA (personal digital assistant)
A hand-held computer. IT normally uses a stylus for user input and often communicate via infared or another wireless signaling method.
phase
A point or stage in a wave's progress over time.
plenum
The area above the ceiling tile or below the subfloor in a building.
point-to-point
A data transmission that involves one transmitter and one receiver.
populated segment
A network segment that contains end nodes, such as workstations.
punch-down block
A panel of data receptors into which horizontal cabling from the workstation is inserted.
radiation pattern
The relative strength over a three-dimensional area of all the electromagnetic energy an antenna sends or receives.
range
The geographical area in which signals issued from an antenna or wireless system can be consistently or accurately received.
reflection
In the context of wireless, the phenomenon that occurs when an electromagnetic wave encounters an obstacle and bounces back towards its source. A wireless signal will bounce off objects whose dimensions are large compared to the signal's average wavelength.
regeneration
The process of retransmitting a digital signal. Unlike amplification, it repeats the pure signal, with of the noise it has accumulated.
repeater
A device used to regenerate a signal.
RFI (radiofrequency interference)
A kind of interference that may be generated by broadcast signals from radio or TV towers.
RG-6
A type of coaxial cable used for television, satellite, and broadband cable connections.
risers
The backbone cabling that provides vertiacl connections between floors of a building.
RJ-11 (Registered Jack - 11)
The standard connector used with unshielded twisted pair cabling (usually CAT 3 or level 1) to connect analog telephones.
RJ-45 (Registered Jack - 45)
The standard connector used with shielded twisted pair and unshielded twisted-pair cabling.
RTT (Round Trip Time)
The length of time it takes for a packet to go from sender to receiver, then back from receiver to sender. It is usually measured in milliseconds.
SC (Subscriber Connector or Standard Connector)
A connector used with single-mode or multimode fiber-optic cable.
scattering
The diffusion of a wireless signal that results from hitting an object that has smaller dimensions compared to the signal's wavelength. It is also related to the roughness of the surface a wireless signal encounters. The rougher the surface, the more likely a signal is to scatter when it hits that surface.
sheath
The outer cover, or jacket, of a cable.
simplex
A type of transmission in which signals may travel in only one direction over a medium.
SMF (single-mode fiber)
A type of fiber-optic cable with a narrow core that carries light pulses along a single path data from one end of the cable to the other end. Data can be transmitted faster and for longer distances on a this type of fiber than on a multi-mode fiber. However it is more expensive.
spread spectrum
A type of wireless tranmission in which lower-level signals are distributed over several frequencies simultaneously. It is more secure than narrowband.
ST (Straight Tip)
A connector used with single-mode or multimode fiber-optic cable.
station
An end node on a network; used most often in the context of wireless networks.
statistical multiplexing
A method of multiplexing in which each node on a network is assigned a seperate time slot for transmission, based on the node's priority.
STP (shielded twisted pair)
A type of 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.
straight-through cable
A twisted-pair patch cable in which the wire terminations in both connectors follow the same scheme.
structured cabling
A method of unifor, enterprise-wide, mutlivendor cabling systems specified by the TIA/EIA 568 Commercial Building Wiring Standard. It is based on a hierarchical design using a high-speed backbone.
subchannel
One of many distinct communication paths established when a channel is multiplexed or modulated.
TDM (time division multiplexing)
A method of multiplexing that assigns a time slot in the flow of communications to every node on the network and, in that time slot, carries data from that node.
Thicknet
An IEEE Physical layer standard for achieving a maximum of 10-Mbps throughput over coaxial copper cable. It is also known as 10BASE-5. Its maximum segement length is 500 meters, and it relies on a bus topology.
Thinnet
An IEEE physical layer standard for achieving 10-Mbps throughput over coaxial copper cable. It is also known as 10BASE-2. Its maximum segment length is 185 meters, and it relies on a bus topology.
throughput
The amount of data that a medium can transmit during a give period of time. It is usually measured in megabits (1,000,000 bits) per second, Mbps. The physical nature of every transmission media determines its potential.
transceiver
A device that transmits and receives signals.
transmission
In networking, the application of data signal to a medium or the progress of data signals over a medium from one point to another.
transmit
To issue signals to the network medium.
twinaxial cable
A type of cable that consists of two copper conductorsat its center surrounded by an insulator, a braided metal sheilding, called braiding, and an outer cover called the sheath or jacket.
twist ratio
The number of twists per meter or foot in a twisted-pair cable.
twisted-pair
A type of cable similar to telephone wiring that consists of color-coded pairs of insulated copper wires, each with a diameter of 0.4 to 0.8 mm, twisted around each other and encased in plastic coating.
unpopulated segment
A network segment that does not contain end nodes, such as workstations. They are also called link segments.
UTP (unshielded twisted-pair)
A type of cabling that consists of one or more insulated wire pairs encased in a plastic sheath. It does not contain additional shielding for the twisted pairs. It is less expensive than STP and less resistant to noise.
volt
The measurment used to describe the degree of pressure an electrical current exerts on a conductor.
voltage
The pressure (sometimes informally referred to as the strength) of an electrical current.
wavelength
The distance between corresponing points on a wave's cycle. Wavelength is inversley proportional to frequency.
WDM (wavelenght division multiplexing)
A multiplexing technique in which each signal on a fiber-optic cable is assinged a different wavelength, which equates to its own subchannel. Each wavelength is modulated with a data signal. In this manner, multiple signals can be simultaneously transmitted in the same direction over a length of fiber.
Webcasting
A broadcast transmission from one Internet-attached node to multiple other Internet-attached nodes.
wire-bound
A type of signal that relies on a physical medium, sich as a cable, for its transmission.
wireless
The signals made of electromagnetic energy that travel through the atmosphere.
wireless spectrum
A continuum of electromagnetic waves used for data and voice communication. It spans frequencies between 9KHz and 300GHz. Each type of wireless service can be associated with one area of it.
WLAN (wireless LAN)
A LAN that uses wireless connections for or all of its transmissions.
What is different about the method used to boost a digital signal’s strength, compared with the method of boosting an analog signal’s strength?
A digital signal requires a repeater, which retransmits the signal in its original form, and an analog signal requires an amplifier, which increases the strength of both the signal and the noise it has accumulated.
A wave with which of the following frequencies would have the shortest wavelength?
100 GHz
What is the origin of the word “modem?”
modulator/demodulator
In wavelength division multiplexing, two modulated signals are guaranteed to differ in what characteristic?
color
What part of a cable protects it against environmental damage?
sheath
What are two advantages of using twisted-pair cabling over coaxial cabling on a network?
. Twisted-pair cable is less expensive.
Twisted-pair cable is required for modern transmission standards, such as 100BASE-T.
What type of topology is required for use with a 100BASE-TX network?
star
How many wire pairs in a CAT 5 cable are actually used for transmission and reception on a 10BASE-T network?
two
What technique is used to achieve 1-Gbps throughput over a CAT 5 cable?
All four wire pairs are used for both transmission and reception.
What type of fiber-optic cable is used most frequently on LANs?
multimode fiber
What is the purpose of cladding in a fiber-optic cable?
It reflects the signal back to the core.
What is the maximum distance specified in the structured cabling standard for a horizontal wiring subsystem?
100 m
You are designing a 100BASE-T network to connect groups of workstations in two different offices in your building. The offices are approximately 250 meters apart. If you only use repeating devices to connect the workstation groups, how many hubs will you need?
two
On a 100BASE-TX Ethernet network, where will you find the transceivers?
In the NICs
What is the maximum amount you should untwist twisted-pair wires before inserting them into connectors?
1⁄2 inch
What frequency range is shared by most new cellular telephones, some portable phones, and also the most popular type of wireless LAN?
2.4–2.4835 GHz
To transmit and receive signals to and from multiple nodes in a three-story house, what type of antenna should an access point use?
omnidirectional