Glossary

110 Connector

Insulation displacement connector (IDC) used in modular jacks, patch panels and cross connects.

1000BASE-T

This IEEE standard defines a Gigabit Ethernet local area network running 1000Mbps base band over unshielded twisted-pair cabling. Throughput over 10Base-T is improved by decreasing bit latency periods and increasing packet speeds.

100BASE-T

This IEEE standard defines an Ethernet local area network running 100Mbps base band over unshielded twisted-pair cabling. Throughput over 10Base-T is improved by decreasing bit latency periods and increasing packet speeds.

10BASE-T

This IEEE standard defines an Ethernet local area network running 10Mbps base band over unshielded twisted pair cabling, typically associated with Category 5.

10GBASE-T

This proposed IEEE standard defines 10 Gigabit Ethernet running 10GMbps over unshielded twisted-pair cabling. Positioned as high speed technology to support Metropolitan Area Networks and other high-demand applications.

66 Block

Cross connect system.

802.11 a/b/g

IEEE standards for wireless LANs. An 802.11a/b/g compatible Wireless Access Point works interchangeably with all three (802.11a, 802.11b, and 802.11g).

AFEXT

See Far End Cross Talk.

ANEXT

See Near End Cross Talk.

AXT

Alien crosstalk (AXT) is electromagnetic noise that can occur in a cable run alongside other signal-carrying cables. The term "alien" arises from the fact that this form of crosstalk occurs between different cables in a group or bundle, rather than between individual wires or circuits within a single cable.

Backboard

Refers to a plywood or metal panel mounted on the wall of a telecom closet to mount the cross connect. Backbone Wiring The physical/electrical interconnections between telecommunications closets and equipment rooms. Cross-connect hardware and cabling in the Main and Intermediate Cross-Connects are considered part of the backbone wiring.

Balun

A transformer used to attach co-axial or twinaxial equipment to twistedpair cabling.

Bandwidth

The difference between the highest and the lowest frequencies of a transmission channel (path for information transmission). Identifies the amount of data that can be sent through a given channel. Measured in Hertz (Hz); higher bandwidth numbers mean higher data capacity. Bend Radius (Fiber) Radius of curvature that a fiber can bend without breaking. Also see Cable Bend Radius..

BICSI

(Building Industry Consulting Service International) BICSI is a non-profit professional association, for the promotion of telecom industry standards.

BNC

A bayonet style co-axial connector.

Bit Error Rate (BER)

In digital applications, the percentage of bits received in error to the total number of bits received. Usually expressed as a number to the power of 10. For example 10 to the fifth power means that one in every 100,000 bits transmitted will be wrong.

Cable Assembly

A fixed length of cable with connectors installed on both ends. Sometimes called a patch cord, patch cable or jumper.

Cable Bend Radius

The amount of bend that can occur before a cable may sustain damage or increased attenuation.

Category 3, CAT 3

A category of performance for inside wire and cable systems. Commonly used for voice applications and data to 10Mbps. Defined by FCC Part 68, ANSI/EIA/TIA-568, TIA TSB-36 and TIA TSB-40.

Category 5, CAT 5

A category of performance for inside wire and cable systems. Used in support of voice and data applications requiring a carrier frequency of up to 100 MHz. Defined by FCC Part 68, EIA/TIA-568, TIA TSB-36 and TIA TSB-40.

Category 5e (Enhanced), CAT 5e

A category of performance for inside wire and cable. Used in support of signaling rates of up to 100MHz over distances of up to 100 meters. Calls for tighter twists, electrical balancing between pairs and fewer cable anomalies. CAT 5e is intended to support 100Base-T, ATM and Gigabit Ethernet.

Category 6, CAT 6

A cable standard for Unshielded Twisted Pair (UTP) supporting signaling rates up to 250 MHz. Applications include 1000Base-T, ATM, Gigabit Ethernet and applications under development. Category 6 Augmented, CAT 6A Also referred to as 10G or 10Gigabit Ethernet. A cable standard for Unshielded Twisted Pair (UTP) supporting signaling rates up to 500 MHz. Applications include 10GBase-T, ATM, 10 Gigabit Ethernet, VoIP, and applications under development. Category of Performance Cabling and cabling component standard adopted by the telecommunications industry.

Channel

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

Co-axial Cable

A cable composed of an insulated central conducting wire wrapped in another cylindrical conductor (the shield). The whole thing is usually wrapped in another insulating layer and an outer protective layer. A co-axial cable has great capacity to carry vast quantities of information.

Compliance

A wiring device that meets all characteristics of a standard is said to be in compliance with that standard.

Conductor

Any substance, usually a wire or cable that can carry an electrical current.

Connecting Block

Also called a terminal block, punch-down block, quick-connect block, or cross-connect block, this plastic block contains metal wiring terminals to establish connections from one group of wires to another. Usually each wire can be connected to several other wires in a bus or common arrangement. There are several types of connecting blocks: 66 clip, BIX, Krone, 110, etc. A connecting block has insulation displacement connections (IDCs), which means you don't have to remove insulation from around the wire conductor before you “punch it down” (terminate it).

Connector

A device that connects wires or fibers in cable to equipment or other wires or fibers. Wire and optical connectors most often join transmission media to equipment or cross connects. Connectors are sometimes referred to as jacks, but though all jacks are connectors, not all connectors are jacks. Consolidation Point An interconnect device that allows the horizontal cable to be split into two parts. Used for zone cabling.

Cross-connect

Distribution system equipment used to terminate and administer communication circuits. In a wire cross-connect, jumper wires or patch cords are used to make circuit connections. In an optical cross-connect, fiber patch cords are used. The cross-connect is located in an equipment room, riser closet, or satellite closet. The Professional's Choice.

Crosstalk

See Near-End Crosstalk.

Daisy Chain

In telecommunications, a wiring method where each telephone jack in a building is wired in series from the previous jack. Daisy chain is NOT the preferred wiring method, since a break in the wiring would disable all jacks “downstream” from the break. See also Home Run.

Data Center

A data center is a facility used for housing a large amount of electronic equipment, typically servers, computers, and communications equipment. Data centers are designed to assure that the servers and the data housed on them are protected from environmental hazards and security breaches. Data centers can be private, serving a single company or a public “utility” serving a variety of companies.

Data Rate

The speed, measured in bits per second, that a particular network transmits data.

db (Decibel)

A dB is a unit of measure of signal strength, usually the relation between a transmitted signal and a standard signal source. Every 3dB equals 50% of signal strength, so therefore a 6dB loss is a loss of 75% of total signal strength.

Delay Skew

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

Demarcation Point

The point of interconnection between telephone company terminal equipment and your building wiring. The protective apparatus or wiring at a subscriber's premises.

Device

As distinguished from equipment. In telecommunications, a “device” is the physical interconnection outlet.Equipment (a computer, phone, fax machine, etc.) then plugs into the device. See also Equipment and Plug.

Drop

Refers to the horizontal cabling for one work area.

EIA

Electronic Industries Alliance. A trade organization of manufacturers which set standards for use of its member companies. Many associations fall under the umbrella of EIA, though it has recently been absorbed by the TIA, or Telecommunications Industry Association. See www.eia.org or www.tiaonline.org.

EIA/TIA

Electronics Industry Association/ Telecommunications Industry Association.

ELFEXT

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

Electromagnetic Interference (EMI)

The interference in signal transmission or reception caused by the radiation of electrical and magnetic fields.

Equipment

As distinguished from Device. Telecom equipment (computers, phones, faxes, etc.) plugs into telecommunications outlets or devices. See also Device.

Ethernet

Type of local area network used for connecting computers, printers, workstations, terminals, etc. within the same building. Ethernet is a physical link and data link protocol that operates over twisted pair wire and over co-axial cable at speeds up to 10Mbps. Far End Crosstalk (FEXT) An electromagnetic interference (EMI), a type of crosstalk, introduced on UTP by close-by wires, usually running in parallel with the FEXT induced wire. "Far End" refers to the inductance of EMI in the end further from the end being measured on the alternate wire in a pair.

F Connector

A common co-axial connector used for video applications (CATV).

FEXT

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

Fiber Optics

A technology in which light beams are used to transport digital information from one point to another via thin filaments of glass. Benefits include the ability to transmit enormous amounts of data over long distance, high bandwidth, relatively low cost, low power consumption, small space needs, total insensitivity to electromagnetic interference, and excellent security control.

Gigabit

When used to describe data transfer rates, it refers to 10 to the 9th power (1,000,000,000) bits. Gigabit Ethernet, abbreviated GbE,supports data transfer rates of 1 Gigabit (1,000 megabits) per second. The first Gigabit Ethernet standard (802.3z) was ratified by the IEEE 802.3 Committee in 1998.

Gigabit Ethernet

The newest and fastest version of Ethernet. Data rate is 1000 Mbps or 1 Gigabit per second. Headroom (Also called Overhead or Margin) The number of decibels by which a system exceeds the minimum defined requirements. The benefit of headroom is that it reduces the bit error rate (BER), and provides a performance 'safety net' to help ensure that current and future high speed applications will run at peak accuracy, efficiency and throughput.

Home Run

Telephone system wiring where the individual cables run from each telephone directly back to the central switching equipment. Home run cabling can be thought of as “star” cabling. Every cable radiates out from the central equipment. See also Star Wiring, Daisy Chain. Horizontal Cabling Includes the work area outlet, distribution cable and connecting hardware in the telecom closet.

Hub

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

IDC (Insulation Displacement Connection)

A type of wire termination where wire is “punched down” into a metal holder which cuts into the insulation wire and makes contact with the conductor, causing the electrical connection to be made.

IDF (Intermediate Distribution Frame)

A metal rack designed to connect cables located in an equipment room or closet. Consists of components that provide the connection between inter-building cabling and the intra-building cabling, i.e. between the Main Distribution Frame (MDF) and individual telephone wiring. There's usually a permanent, large cable running between the MDF and IDF. The changes in wiring are done at the IDF.

IEEE

Institute of Electrical and Electronics Engineers. Develops Local Area Network standards and Metropolitan Area Network standards.

Impedance

The total opposition (i.e. resistance and reactance) a circuit offers to the flow of alternating current. It is measured in ohms, and the lower the ohmic value, the better the quality of the conductor.

Insertion Loss

The difference in the amount of power received before and after something is inserted into the circuit. In optical fiber, insertion loss is the optical power loss due to all causes, usually expressed as decibel/kilometer.