TERM DEFINITION   1000BASE-T A recent LAN standard for implementing 1000 Mbps Ethernet on Category 5 cable.See also Gigabit Ethernet.   100BASE-T The twisted pair version of 100 Mbps Ethernet.Requires Category 5 cabling.   10BASE2 Also called Thinnet.10 Mbps Ethernet on thin (RG58) coaxial cable.   10BASE5 Also called Thicknet.10 Mbps Ethernet on thick coaxial cable.   10BASE-T 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.   3270 (IBM) A mainframe computer.Originally implemented on RG62 coax.Now generally implemented on UTP cable using baluns.   66 Block A legacy cross connect system.Similar in function to AMP 110Connect XC.   AS/400 (IBM) A midrange computer system.Originally implemented on twinaxial cable.Now generally implemented on UTP cable using baluns.   Attenuation The amount of signal lost as it travels through the cabling system.   Backboard Refers to a plywood panel mounted on the wall of a telecom closet.Used to mount the cross connect.   Backbone cabling Cabling between floors in a building or between buildings in a campus.   Balun A transformer used to attach coaxial or twinaxial equipment to twisted pair cabling.   BNC 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.   Channel The entire horizontal cabling system. Everything between the computer and the LAN hub in the telecom closet, excluding the equipment connections.   Coax 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.   Cross connect (XC) Connecting hardware used to patch between two groups of cables (horizontal to backbone, for example).AMP 110Connect XC.   Data rate The speed, measured in bits per second, that a particular network (or other application) transmits data.   dB 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.   Drop Refers to the horizontal cabling for one work area, as in "The job has 100 drops."   ELFEXT 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.   Ethernet 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).   FEXT Far End Crosstalk. Unwanted noise coupled onto a receive pair from a transmit pair at the far end of the system.   Gbps A data rate. Gigabits per second.A gigabit is one billion bits.   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.   Hub Network device, usually in the telecom closet, that stations connect to.   IDC Insulation Displacement Connector.A style of connector that slices through the cable insulation to make a connection.Eliminates the need to strip insulation.   IEEE 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.   Impedance The total opposition to the flow of alternating current in a conductor.   Jumper Usually unjacketed twisted pair wire used to make a cross connection.   Kbps A data rate. Kilobits, or thousands of bits, per second.   LAN Local Area Network.Usually confined to one building or even one floor.Large companies may have several LANs connected by an internetwork or backbone network.   Link The part of the horizontal cabling system between the work area outlet and the telecom closet termination.   MAC 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.   Mbps A data rate. Megabits, or millions of bits, per second.   MHz 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.A "telephone jack".   Modular plug The standard male connector for twisted pair cable.A "telephone plug".   MT-RJ A small form factor, dual fiber connector.   Multimode 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.   MUTOA See multi-user outlet.   NEXT Near End Crosstalk.The unwanted noise coupled into a device's receive circuit from its transmit circuit.   NIC Network interface card.Allows a PC to attach to a network.   Node A device connected to a network.   Outlet Where the horizontal cabling terminates in the work area.   Patch cord A cable assembly with (usually) a plug on each end, used to make a cross connection.   Patch panel A rack-mountable panel (usually 19" wide) containing connecting hardware.Used to patch between groups of cables and equipment.   PBX Private Branch Exchange.The premises telephone switch.Handles telecom functions.   Plenum A chamber that houses environmental air transfer.Plenum-rated cable is required in such locations.   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.   PS ELFEXT See power sum and ELFEXT.   PS NEXT See power sum and NEXT.   Punchdown Refers to IDC connectors and the method used to terminate them.   Rack Used to mount patch panels, enclosures and equipment in the telecom closet.Usually 19" wide by 7' high.   Return loss A measure of the signal reflected back toward the transmitter as a result of impedance variations in the cabling system.   Riser Backbone cabling connecting telecom closets situated vertically on separate floors.   RJ11 A wiring pattern for 6-position modular jacks.Used to refer to the jacks themselves.   RJ21 A wiring pattern for a 25-pair (AMP CHAMP) connector.Also used to refer to the connectors themselves.   RJ45 A wiring pattern for8-position modular jacks.Used to refer to the jacks themselves.   SC connector A duplex optical fiber connector. The standard connector for optical fiber per the 568 cabling standard.   Singlemode 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.   STP Shielded Twisted Pair.2-Pair 150 ohm shielded cable.   Switch A type of network hub.Provides higher bandwidth than shared hubs.   System/3X (IBM) The predecessor of the AS/400.   T568A and B The two standard wiring patterns for 8-position modular jacks.   Telco Short for telecommunications (or telephone company).   Telco connector Refers to a 25-pair (AMP CHAMP) connector.   Telecom closet Telecommunications closet. The area of the building that houses the termination of the horizontal cabling.May also contain LAN electronics.   Thicknet IEEE 10BASE5.10 Mbps Ethernet on thick coaxial cable.   Thinnet 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.   UTP Unshielded twisted pair cable. Cable made from pairs of wires which have been twisted together.   Wiring closet See telecom closet.   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.