Technical Help


A recent LAN standard for implementing 1000 Mbps Ethernet on Category 5 cable.See also Gigabit Ethernet.


The twisted pair version of 100 Mbps Ethernet.Requires Category 5 cabling.


Also called Thinnet.10 Mbps Ethernet on thin (RG58) coaxial cable.


Also called Thicknet.10 Mbps Ethernet on thick coaxial cable.


10 Mbps Ethernet on twisted-pair (Category 3) cable.

110 Connector

A popular insulation displacement connector (IDC) used modular jacks, patch panels and cross connects.

AS/400 (IBM)

A midrange computer system.Originally implemented on twinaxial cable.Now generally implemented on UTP cable using baluns.


The amount of signal lost as it travels through the cabling system.

Backbone cabling

Cabling between floors in a building or between buildings in a campus.


A transformer used to attach coaxial or twinaxial equipment to twisted pair cabling.


A bayonet style coaxial connector.

Category 3

A performance classification for twisted pair cables, connectors and systems.Specified to 16 MHz.Suitable for voice and data applications up to 10 Mbps.

Category 5

A performance classification for twisted pair cables, connectors and systems.Specified to 100 MHz.Suitable for voice and data applications up to 155 Mbps (possibly 1000 Mbps).

Category 5e

Also called Enhanced Category 5.A performance classification for twisted pair cables, connectors and systems.Specified to 100 MHz.Suitable for voice and data applications up to 1000 Mbps.

Category 6

A performance classification for twisted pair cables, connectors and systems.Specified up to 250 MHz.


The entire horizontal cabling system. Everything between the computer and the LAN hub in the telecom closet, excluding the equipment connections.


Short for coaxial.Single-conductor cables with braided shields.Used in the 80's for data transmission.Now generally replaced with UTP for data.Still used for video.

Consolidation point

An interconnect device that allows the horizontal cable to be split into two parts.Used for zone cabling.

Data rate

The speed, measured in bits per second, that a particular network (or other application) transmits data.


Abbreviation for decibel.The logarithmic ratio of two powers, voltages or currents.

Delay skew

The difference in propagation delay between the slowest and fastest pairs in a cable or system.


Equal Level Far End Crosstalk. A measure of FEXT which accounts for the attenuation of the cabling system.

Enhanced Category 5

Also called Category 5e.A performance classification for twisted pair cables, connectors and systems.Specified to 100 MHz.Suitable for voice and data applications up to 1000 Mbps.


The most common network protocol in use.A protocol is a set of rules enabling data communications. Based originally on a bus topology.

F connector

A common coaxial connector used for video applications (CATV).


Far End Crosstalk. Unwanted noise coupled onto a receive pair from a transmit pair at the far end of the system.


A data rate. Gigabits per second.A gigabit is one billion bits.


Gigabit Ethernet Passive Optical Network(GEPON) is a point-to-multipoint, fiber to the premises network architecture in which unpowered optical splitters are used to enable a single optical fiber to serve multiple premises, typically 32.

Gigabit Ethernet

The newest (1999) and fastest version of Ethernet.Data rate is 1000 Mbps or 1 Gigabit per second.

Horizontal cabling

Includes the work area outlet, distribution cable and connecting hardware in the telecom closet.


Network device, usually in the telecom closet, that stations connect to.


Insulation Displacement Connector.A style of connector that slices through the cable insulation to make a connection.Eliminates the need to strip insulation.


Institute of Electrical and Electronics Engineers. 802 Group develops Local Area Network standards and Metropolitan Area Network standards.

IEEE 802.3

Usually referred to as Ethernet.A networking protocol.

IEEE 802.5

Usually referred to as token ring.A networking protocol.


The total opposition to the flow of alternating current in a conductor.


Usually unjacketed twisted pair wire used to make a cross connection.


A data rate. Kilobits, or thousands of bits, per second.


Local Area Network (LAN) is a computer network covering a small geographic area, like a home, office, or group of buildings e.g. a school. The defining characteristics of LANs, in contrast to wide-area networks (WANs), include their much higher data-transfer rates, smaller geographic range, and lack of a need for leased telecommunication lines.


A fiber laser is a laser in which the active gain medium is an optical fiber doped with rare-earth elements such as erbium, ytterbium, neodymium, dysprosium, praseodymium, and thulium. They are related to doped fiber amplifiers, which provide light amplification without lasing. Fiber nonlinearities, such as stimulated Raman scattering or four-wave mixing can also provide gain and thus serve as gain media for a fiber laser.


The part of the horizontal cabling system between the work area outlet and the telecom closet termination.


Moves Adds and Changes: When data and voice services (to include: outlets and cabling, patching, etc.) of a given location are moved to a new location or removed completely.


A data rate. Megabits, or millions of bits, per second.


Megahertz.Millions of cycles (Hertz) per second. A frequency or frequency range (bandwidth) through which a cabling system is specified.

Modular jack

The standard female connector for twisted pair cable.

Modular plug

The standard male connector for twisted pair cable.


A small form factor, dual fiber connector.


A type of optical fiber in which the light travels in multiple paths. Utilizes LEDs or lasers as light sources.

Multi-user outlet

A work area outlet designed to support multiple users. Also called multi-user telecommunications outlet assembly or MUTOA.


See multi-user outlet.


Near End Crosstalk.The unwanted noise coupled into a device's receive circuit from its transmit circuit.


Network interface card.Allows a PC to attach to a network.


A device connected to a network.

Optical Attenuator

An optical attenuator is a device used to reduce the power level of an optical signal, either in free space or in an optical fiber. They are commonly used in fiber optic communications. The basic types of optical attenuators are fixed, step-wise variable, and continuously variable.

Optical Coupler

Optical coupler is passive optical device that connects three or more fiber ends, dividing one input between two or more outputs, or combining two or more inputs into one output. Optical coupler is generally deployed in passive optical network.

Optical Receiver

The main component of an optical receiver is a photodetector that converts light into electricity through the photoelectric effect. The photodetector is typically a semiconductor-based photodiode, such as a p-n photodiode, a p-i-n photodiode, or an avalanche photodiode. Metal-semiconductor-metal (MSM) photodetectors are also used due to their suitability for circuit integration in regenerators and wavelength-division multiplexers.

Optical Transmitter

The most commonly-used optical transmitters are semiconductor devices such as light-emitting diodes (LEDs) and laser diodes. The difference between LEDs and laser diodes is that LEDs produce incoherent light, while laser diodes produce coherent light. For use in optical communications, semiconductor optical transmitters must be designed to be compact, efficient, and reliable, while operating in an optimal wavelength range, and directly modulated at high frequencies.


An OTDR injects a series of optical pulses into the fiber under test. It also extracts, from the same end of the fiber, light that is scattered back and reflected back from points in the fiber where the index of refraction changes. (This is equivalent to the way that an electronic TDR measures reflections caused by changes in the impedance of the cable under test.) The intensity of the return pulses is measured and integrated as a function of time, and is plotted as a function of fiber length.
An OTDR may be used for estimating the fiber's length and overall attenuation, including splice and mated-connector losses. It may also be used to locate faults, such as breaks.


Where the horizontal cabling terminates in the work area.

Patch cord

A cable assembly with (usually) a plug on each end.

Patch panel

A rack-mountable panel (usually 19" wide) containing connecting hardware.Used to patch between groups of cables and equipment.


Private Branch Exchange.The premises telephone switch.Handles telecom functions.


Plesiochronous Digital Hierarchy (PDH) is a technology used in telecommunications networks to transport large quantities of data over digital transport equipment such as fiber optic and microwave radio systems.


A chamber that houses environmental air transfer.Plenum-rated cable is required in such locations.

Power Meter

Optical power meter is a device used to measure the energy in an optical signal. A typical device consists of a display unit and a calibrated sensor. Power meters are calibrated using a traceable calibration standard such as an NIST standard.

Power sum

A mathematical addition of noise from multiple disturbers. Applied to NEXT and ELFEXT requirements.

Propagation delay

The amount of time it takes a signal to travel through a cable or system.

Propagation delay skew

The difference in propagation delay between the slowest and fastest pairs in a cable or system.


See power sum and ELFEXT.


See power sum and NEXT.


Refers to IDC connectors and the method used to terminate them.


Used to mount patch panels, enclosures and equipment in the telecom closet.

Return loss

A measure of the signal reflected back toward the transmitter as a result of impedance variations in the cabling system.


Backbone cabling connecting telecom closets situated vertically on separate floors.


A wiring pattern for 6-position modular jacks.Used to refer to the jacks themselves.


A wiring pattern for8-position modular jacks.Used to refer to the jacks themselves.


Router, including broadband and wireless router, is a device whose software and hardware are usually tailored to the tasks of routing and forwarding information. It is used to connect two or more logical subnets, which do not necessarily map one-to-one to the physical interfaces of the router.

SC connector

A duplex optical fiber connector. The standard connector for optical fiber per the 568 cabling standard.


Synchronous digital hierarchy (SDH) and synchronous optical network (SONET) based on circuit mode communication, meaning that each connection achieves a constant bit rate and delay refer to a group of fiber-optic transmission rates that can transport digital signals with different capacities.


A type of optical fiber in which the light travels in a single path. Utilizes lasers as a light source.

ST connector

A bayonet style optical fiber connector.An alternate style per the 568 standard.


Shielded Twisted Pair.2-Pair 150 ohm shielded cable.


A type of network hub.Provides higher bandwidth than shared hubs.

T568A and B

The two standard wiring patterns for 8-position modular jacks.


Short for telecommunications (or telephone company).

Telecom closet

Telecommunications closet. The area of the building that houses the termination of the horizontal cabling.May also contain LAN electronics.


IEEE 10BASE5.10 Mbps Ethernet on thick coaxial cable.


IEEE 10BASE2. 10 Mbps Ethernet on thin (RG58) coaxial cable.

Token ring

A networking protocol based on a token-passing ring.

Twisted pair cable

Cable made from pairs of wires which have been twisted together.


Unshielded twisted pair cable. Cable made from pairs of wires which have been twisted together.


Wavelength-division multiplexing (WDM) is a technology which multiplexes multiple optical carrier signals on a single optical fiber by using different wavelengths of laser light to carry different signals. This allows for a multiplication in capacity, in addition to enabling bidirectional communications over one fiber.

Wiring closet

See telecom closet.


A wireless LAN( WLAN) is a wireless local area network, which is the linking of two or more computers without using wires. WLAN utilizes spread-spectrum or OFDM modulation technology based on radio waves to enable communication between devices in a limited area, also known as the basic service set. This gives users the mobility to move around within a broad coverage area and still be connected to the network.

Work area

Where the users' communications equipment resides.The part of the cabling system between the outlet and the equipment.

Zone cabling

An architectural concept which splits the horizontal cabling into two sections. Eliminates the need to replace the entire horizontal cable in moves, adds and changes.