Networking Unit 5: Network Cabling
1000Base-T
A Physical layer standard for achieving 1 Gbps over twisted-pair cable.
10GBase-T
A Physical layer standard for achieving 10-Gbps data transmission over twisted-pair cable.
1000Base-LX
A Physical layer standard for networks that specifies 1-Gbps transmission over fiber-optic cable using baseband transmission. The LX represents its reliance on long wavelengths of 1300 nanometers.
1000Base-SX
A Physical layer standard for networks that specifies 1-Gbps transmission over fiber-optic cable using baseband transmission. The SX represents its reliance on short wavelengths of 850 nanometers.
100Base-T
A Physical layer standard for networks that specifies base band transmission, twisted-pair cabling, and 100-Mbps throughput. 100Base-T is also known as Fast Ethernet.
core
A cable's central component that is designed to carry a signal, such as glass or plastic fibers in fiberoptic cable or strands of copper in twisted-pair cable.
open circuit
A circuit in which necessary connections are missing, such as occurs when a wire breaks.
BNC connector
A coaxial cable connector type that uses a turn-and-lock (or bayonet) style of coupling.
hot-swappable
A component that can be installed or removed without disrupting operations.
F-connector
A connector used to terminate coaxial cable that transmits television and cable broadband signals.
SC (Subscriber Connector or Standard Connector)
A connector with a 2.5-mm ferrule that is used with single-mode, fiber-optic cable.
ST (Straight Tip)
A connector with a 2.5-mm ferrule that is used with single-mode, fiber-optic cable.
LED (light-emitting diode)
A cool-burning, longlasting technology that creates light by the release of photons as electrons move through a semiconductor material.
FDP (Fiber Distribution Panel)
A device on a rack where fiber cables converge, connect with each other, and connect with fiber-optic terminal equipment from the ISP.
media converter
A device that enables networks or segments running on different media to interconnect and exchange signals.
light meter
A device that measures the amount of light power transmitted on a fiber-optic line. Also called OPM (optical power meter).
OPM (optical power meter)
A device that measures the amount of light power transmitted on a fiber-optic line. Also called light meter.
cable tester
A device that tests cables for one or more of the following conditions: continuity, segment length, distance to a fault, attenuation along a cable, near-end cross-talk, and termination resistance and impedance.
repeater
A device used to regenerate a digital signal in its original form. Repeaters operate at the Physical layer of the OSI model.
CFP (Centum form-factor Pluggable)
A fiber-optic transceiver intended for 100-Gbps network connections.
QSFP (quad small form-factor pluggable)
A fiber-optic transceiver that complies with the 802.3ba standard, squeezing four channels in a single transceiver and supporting data rates up to 40 Gbps (4 x 10 Gbps).
BiDi transceiver
A fiber-optic transceiver that supports bidirectional transmission on both its ports.
Cat 5 (Category 5)
A form of UTP that contains four wire pairs and supports up to 100-Mbps throughput and a 100-MHz signal rate. Required minimum standard for Fast Ethernet.
multiplexing
A form of transmission that allows multiple signals to travel simultaneously over one medium.
TDR (time domain reflectometer)
A high-end instrument for testing the qualities of a cable.
Cat 5e (Enhanced Category 5)
A higher-grade version of Cat 5 wiring that supports a signaling rate of up to 350 MHz and a maximum throughput of 1 Gbps, making it the required minimum standard for Gigabit Ethernet.
Cat 6a (Augmented Category 6)
A higher-grade version of Cat 6 wiring that further reduces attenuation and crosstalk, and allows for potentially exceeding traditional network segment length limits.
RFI (Radio Frequency Interference)
A kind of electromagnetic interference that can be generated by broadcast signals from radio or TV antennas.
modal bandwidth
A measure of the highest frequency of signal a multimode fiber-optic cable can support over a specific distance. Modal bandwidth is measured in MHz-km.
PoE+
A method of delivering more current (up to 25.5 watts) than PoE does to devices using Ethernet connection cables.
PoE (Power over Ethernet)
A method of delivering up to 15.4 watts to devices using Ethernet connection cables.
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.
transceiver
A modular interface that can be inserted in a switch to connect its motherboard with an external, fiber-optic cable.
CWDM (Coarse Wavelength Division Multiplexing or Coarse WDM)
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.
DWDM (Dense Wavelength Division Multiplexing or Dense WDM)
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.
OTDR (Optical Time-Domain Reflectometer)
A performance testing device for use with fiber-optic networks which can accurately measure the length of the fiber, locations of faults, and many other characteristics.
TX/RX reverse
A problem caused by mismatched pinout standards, resulting in near end crosstalk.
speed and duplex mismatch
A problem that occurs when neighboring devices are using different speed or duplex configurations and results in failed transmissions.
patch cable
A relatively short section (usually between 3 and 25 feet) of cabling with connectors on both ends.
multimeter
A simple instrument that can measure multiple characteristics of an electric circuit, including its resistance, voltage, and impedance.
tone locator
A small electronic device that emits a tone when it detects electrical activity on a wire pair. When used in conjunction with a tone generator, it can help locate the termination of a wire pair. Also called a probe.
tone generator
A small electronic device that issues a signal on a wire pair. When used in conjunction with a tone locator, it can help locate the termination of a wire pair. Also called a toner.
SFP (Small form-factor pluggable)
A standard hot-swappable network interface used to link a connectivity device's backplane with fiber-optic or copper cabling.
TIA/EIA 568B
A standard pinout for RJ-45 plugs commonly used in homes and businesses.
TIA/EIA 568A
A standard pinout for RJ-45 plugs required by the federal government on all federal contracts.
GBIC (Gigbit interface converter )
A standard type of modular interface that may contain RJ-45 or fiber-optic cable ports (such as LC, SC, or ST). They are inserted into a socket on a connectivity device's backplane. Pronounced jee-bick.
crimper
A tool used to attach a connector onto the end of a cable, causing the internal RJ-45 pins to pierce the insulation of the wires, thus creating contact between the conductors at each wire.
jitter
A transmission flaw caused by packets experiencing varying amounts of delay and arriving out of order. Also called PDV (packet delay variation).
bidirectional
A transmission method that allows each fiber cable to carry data in both directions.
loopback adapter
A troubleshooting tool that plugs into a port (for example, an RJ-45 or fiber-optic port) and crosses the transmit line with the receive line, allowing outgoing signals to be redirected back into the computer for testing. Also called a loopback plug.
cable performance connector
A troubleshooting tool that tests cables for continuity, but can also measure crosstalk, attenuation, and impedance; identify the location of faults; and store or print cable testing results. Also called line tester, certifier, or network tester.
Cat 6 (Category 6)
A twisted-pair cable that contains four wire pairs, each wrapped in foil insulation. Additional foil insulation can cover the bundle of wire pairs, and a fire-resistant plastic sheath might cover the second foil layer. The foil insulation provides excellent resistance to crosstalk and enables Cat 6 to support a signaling rate of 250 MHz and throughput up to 10 Gbps.
Cat 7 (Category 7)
A twisted-pair cable that contains multiple wire pairs, each separately shielded then surrounded by another layer of shielding within the jacket.
Cat 7a (Augmented Category 7)
A twisted-pair cable that contains multiple wire pairs, each separately shielded then surrounded by another layer of shielding within the jacket.
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 as compared with the other end.
straight-through cable
A twisted-pair patch cable in which the wire terminations in both connectors follow the same scheme. Typically used to connect end-user devices (e.g. workstations or printers) to network devices (switches, routers, patch boards)
toner and probe kit
A two-piece tool that includes both a tone generator and a tone locator. Used together, they can help locate the termination of a wire pair.
Fast Ethernet
A type of Ethernet network that is capable of 100-Mbps throughput.
Gigabit Ethernet
A type of Ethernet network that is capable of 1000-Mbps, or 1-Gbps, throughput. Requires Cat 5e or higher cabling.
SFP+
A type of SFP that can send and receive data at rates of up to 16 Gbps.
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. Every two wires are twisted around each other to form pairs, and all the pairs are encased in a plastic sheath.
coaxial cable
A type of cable that consists of a central metal conducting core, surrounded by an insulator, shielding, and an outer cover. Today coaxial cable, called "coax" for short, is used to connect cable Internet and cable TV systems.
RG-59 (radio guide 59)
A type of coaxial cable characterized by a 75-ohm impedance and a 20 or 22 AWG core conductor, usually made of braided copper and used for relatively short connections.
RG-6 (Radio Guide 6)
A type of coaxial cable with an impedance of 75 ohms and an 18 AWG core conductor. RG-6 is used for television, satellite, and broadband cable connections.
DB-25 Connector
A type of connector with 25 pins that's used in serial communication and conforms to the RS-232 standard.
DB-9 Connector
A type of connector with nine pins that's used in serial communication and conforms to the RS-232 standard.
MMF (multimode fiber)
A type of fiber-optic cable containing a core that is usually 50 or 62.5 microns in diameter, over which many pulses of light generated by a laser or LED (light-emitting diode) travel at different angles.
SMF (single mode fiber)
A type of fiber-optic cable with a narrow core of 8 to 10 microns in diameter that carries light pulses along a single path from one end of the cable to the other end.
FDM (Frequency Division Multiplexing)
A type of multiplexing that assigns a unique frequency band to each communications subchannel. Signals are modulated with different carrier frequencies, then multiplexed to simultaneously travel over a single channel.
STDM (statistical time division multiplexing)
A type of multiplexing that assigns time slots to nodes (similar to TDM), but then adjusts these slots according to priority and need.
duplex
A type of transmission in which signals may travel in both directions over a medium simultaneously.
full-duplex
A type of transmission in which signals may travel in both directions over a medium simultaneously; also called, simply, duplex.
continuity tester
An instrument that tests whether voltage (or light, in the case of fiber-optic cable) issued at one end of a cable can be detected at the opposite end of the cable. Also called cable checker or cable tester.
Cat 3 (Category 3)
An outdated form of UTP that contained four wire pairs and could carry up to 10 Mbps, with a possible bandwidth of 16 MHz.
short circuit
An unwanted connection, such as when exposed wires touch each other.
FEXT (Far-End Crosstalk )
Crosstalk measured at the far end of the cable from the signal source.
NEXT (near end crosstalk)
Crosstalk that occurs between wire pairs near the source of a signal.
Alien Crosstalk
Electromagnetic interference induced on one cable by signals traveling over a nearby cable.
QSFP +
Generally the same technology as QSFP while supporting data rates over 40 Gbps.
bit rate
In digital transmissions, a measurement of throughput and bandwidth that is expressed as bits transmitted per second.
802.3at
The IEEE standard that improves upon the older 802.3af by supplying more power (up to 25.5 watts) over Ethernet connections.
continuity
The ability of a cable to carry a signal to its destination.
Throughput
The amount of data that a medium transmits during a given period of time. Throughput is usually measured in megabits (1,000,000 bits) per second, or Mbps.
throughput
The amount of data that a medium transmits during a given period of time. Throughput is usually measured in megabits (1,000,000 bits) per second, or Mbps.
Bandwidth
The amount of data that can be transmitted over a network in a given amount of time.
optical loss
The degradation of a light signal on a fiber-optic network as it travels away from its source.
ferrule
The extended tip of a fiber-optic cable connector that encircles the fiber strand to keep it properly aligned and ensure that it makes contact with the receptacle in a jack or other connector.
cladding
The glass or plastic shield around the core of a fiber-optic cable. Cladding reflects light back to the core in patterns that vary depending on the transmission mode.
APC (Angle Polished Connector)
The latest advancement in ferrule technology that uses the principles of reflection to its advantage by placing the end faces of the highly polished ferrules at an angle to each other, thus reducing the effect of back reflection.
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. RTT is usually measured in milliseconds.
Attenuation
The loss of a signal's strength as it travels away from its source.
LC (local connector)
The most common 1.25-mm ferrule connector, which is used with single-mode, fiber-optic cable.
MTRJ (Mechanical Transfer-Registered Jack)
The most common type of connector used with multimode fiber-optic cable.
twist radio
The number of twists per meter or foot in a twisted-pair cable.
pinout
The pin numbers and color-coded wire assignments used when terminating a cable or installing a jack, as determined by the TIA/EIA standard.
RJ-45 (registered jack 45)
The standard connector used with shielded twisted-pair and unshielded twisted-pair cabling.
RJ-11 (registered jack 11)
The standard connector used with unshielded twisted-pair cabling (usually Cat 3) to connect analog telephones.
console port
The type of port on a router used to communicate with the router itself, such as when making configuration changes to the device.
Ethernet Port
The type of port that connects devices on a LAN; it uses an RJ-45 connector.
802.3af
`The IEEE standard that specifies a way of supplying electrical power (up to 15.4 watts) over twisted-pair Ethernet connections, also known as PoE (Power over Ethernet).
