FAQ
MODULAR WIRING REFERENCE
There are four basic modular jack styles. The 8-position modular outlets are commonly and incorrectly referred to as “RJ45”. The 6-position modular jack is commonly referred to as an RJ11. Using these terms can sometimes lead to confusion since the RJ designations actually refer to very specific wiring configurations called universal Service Order Code (USOC). The designation ‘RJ’ means Registered Jack. Each of these basic jack styles can be wired for different RJ configurations. For example, the 6-position jack can be wired as an RJ11C (1-pair), RJ(2-pair), or RJ25C (3-pair) configuration. An 8-position jack can be wired for configurations such as RJ61C(4-pair) and RJ48C. The keyed 8-position jack can be wired for RJ45S, RJ46S, and RJ47S. The fourth modular jack style is a modified version of the 6-position jack (modified modular jack or MMJ). It was designed by Digital Equipment Corporation (DEC) along with the modified modular plug (MMP) to eliminate the possibility of connecting DEC data equipment to voice lines and vice versa.
 8-position
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 8-position keyed
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 6-position
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 6-position modified
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MODULAR PLUG PAIR CONFIGURATIONS
It is important that the pairing of wires in the modular plug match the pairs in the modular jack as well as the horizontal and backbone wiring. If they do not, the data being transmitted may be paired with incompatible signals.
Modular cords wired to the T568A color scheme on both ends are compatible with T568B systems and vice versa.
STRAIGHT-THROUGH OR REVERSED?
Modular cords are used for two basic applications. One application uses them for patching between modular patch panels. When used in this manner modular cords should always be wired “straight-through” (pin 1 to pin 1, pin 2 to pin 2, pin 3 to pin 3, etc.). The second major application used modular cords to connect the workstation equipment (PC, phone, GAX, etc). To the modular outlet. These modular cords may either be wired “straight-through” or “reversed” (pin 1 to pin 6, pin 2 to pin 5, pin 3 to pin 4, etc.) depending on the system manufacture’s specifications. This “reversed” wiring is typically used for voice systems. The following is a guide to determine what type of modular cord you have.
HOW TO READ A MODULAR CORD
Align the plugs side-by-side with the contacts facing you and compare the wire colors from left to right. If the colors appear in the same order on both plugs, the cod is wired “straight-through”. If the colors appear reversed on the second plug (from right to left), the cord is wired “reversed”.
COMMON OUTLET CONFIGURATIONS
Two wiring schemes have been adopted by the “568-B.1 and “11801 standards. They are nearly identical except that pairs two and three are reversed. T568A is the preferred scheme because it is compatible with 1 or 2-pair USOC systems. Either configuration can be used for Integrated Services Digital Network (ISDN) and high speed data applications. Transmission categories 3, 5, 5e, and 6 are only applicable to this type of pair grouping.
USOC wiring is available for 1-, 2-, 3-, or 4-pair systems. Pair 1 occupies the center conductors, pair 2 occupies the next two contacts out, etc. One advantage to this scheme is that a 6-position plug configured with 1, 2, or 3 pairs can be inserted into and 8-position jack and still maintain pair continuity. A note of warning though, pins 1 and 8 on the jack may become damaged from this practice. A disadvantage is the poor transmission performance associated with this type of pair sequence. None of these pair schemes is cabling standard compliant.
10BASE-Twiring specifies and 8-position jack but used only two pairs. These are pairs two and three of T568A and T568B schemes.
Token Ring wiring uses either an 8-position or 6-position jack. The 8-position format is compatible with T568A, T568B, and USOC wiring schemes. The 6-position is compatible with 1- or 2-pair USOC wiring.
The MMJ is a unique wiring scheme for DEC equipment.
ANSI X3T9.5 TP-PMD uses the two outer pairs of an 8-position jack. These positions are designated as pair 3 and pair 4 of the T568A wiring scheme. This wiring scheme is also used for ATM.
CATEGORY 3
The characteristics are specified up to 16 MHz. It is typically used for voice and data transmission rates up to and including 10 Mbps, e.g. IEEE 802.5, 4 Mbps UTP and IEEE 802.3 10Base-T Ethernet.
CATEGORY 4
The Characteristics are specified up to 20 MHz. It is typically used for voice and data transmission rates up to and including 16 Mbps, e.g. IEEE 802.5, 4/16 Mbps UTP.
CATEGORY 5
The characteristics are specified up to 100 MHz. It is typically used for voice and data transmission rates up to and including 100 Mbps, e.g. IEEE 802.5, 16 Mbps UTP, ANSI X3T9.5 100 Mbps TPDDI, 100Base-TX and 155 Mbps ATM.
CATEGORY 5e
The characteristics are specified up to 100 MHz. It supports Fast Ethernet, 155 Mpbs ATM and Gigabit Ethernet. It has Power Sum performance designed for any combination of transmission schemes and a minimum of 3 dB headroom from Category 5.
CATEGORY 6
The characteristics are specified up to 250 MHz. At the time of this writing, Category 6 is currently a proposal only and its subject to change. Standards should be defined at a future date.
ACR
Attenuation to Near-End Crosstalk Ratio (ACR) is the difference between the crosstalk and the attenuation. Improved ACR provides additional performance and leads to the development of higher bandwidth and increased data rate transmission protocols.
ATTENUATION
Attenuation is a measure of signal power loss due to the connecting hardware and is derived from swept frequency voltage measurements on short lengths of 100 Ohm twisted-pair leads before and after inserting the connector under test.
NEXT
Next is a measure of signal coupling from one circuit to another within a connector and is derived from swept frequency voltage measurements on short lengths of 100 meters (twisted-pair test leads terminated to the connector under test). A balanced input signal is applied to a disturbing pair of the connector while the induced signal on the disturbed pair is measured at the near-end of the test leads.
POWER SUM CROSSTALK
Power Sum crosstalk is the addition of the crosstalk power from several transmitting signals on different pairs. Power Sum NEXT (near-end crosstalk) and FEXT (far-end crosstalk) compliance ensures that a cabling channel will not exceed crosstalk performance requirements when all four pair are operating simultaneously such as in the Gigabit Ethernet 1000Base-T protocol.
FEXT
Far-End Crosstalk (FEXT) is the noise induced by a transmitter at the near end into the far end receiver due to unwanted signal coupling. FEXT can be a factor in multi-pair, bi-directional signaling such as Gigabit Ethernet.
RETURN LOSS
Return loss is the reflected signal power of a transmitted signal. Better return loss improves signal integrity and increases performance for dual-duplex transmissions.
What type of copper cable should be used when connecting Fast Ethernet networks?
For 100Base-TX or 100Mbps networking, JE recommends Category 5e cable.
What is UTP and STP mean?
UTP stands for Unshielded Twisted Pairs and STP stands for Shielded Twisted Pair.
What is a crossover cable?
A crossover cable is a 2-pair cable that crosses over pins 1,2/3,6. This cable is normally used to connect 2 computers directly or cascade 2 hubs without the use of an uplink port.
Can you use telephone patch cords to connect a LAN?
Using telephone cords to connect a LAN is not recommended. Telephone cords are designed to work with low speed applications such as voice transmission.
Do you need a special tool when working with 110-Type patch panels and jacks?
Yes, you need to use a 110-Type impact tool in order to properly terminate your connections.
Do you need a hub if using coaxial cable on a LAN?
No, a hub is not needed when you are using coaxial cable. You can directly connect each computer by using coaxial cable but you must put terminators on each end of the cable.
What is Crosstalk?
Crosstalk is the unwanted introduction of signals from one channel or pair to another.
What is difference between a “Channel” and a “Link”?
These terms describe two Category certification tests. These tests differ in how much of a horizontal cabling run is included for testing. The basic difference is that a link includes patching and /or equipment cords as well.
What effect does workmanship and equipment have upon cabling performance?
One reason why channel and link tests have evolved has to do with the quality of the workman ship and materials. Channel performance is greatly affected by cable characteristics, connecting hardware, patch cords and cross-connect wiring, as well as the total number of connections and the care with which they are installed and maintained. You can go a long way toward preserving performance by simply choosing good quality components and installing them with care and proper techniques.
Why should I test the cable immediately after pull-in?
This simplifies subsequent troubleshooting. By testing the system at this point, should a problem arise after the equipment is installed, the cabling system can be ruled out as a probable cause.
10Base-2 - A variant of Ethernet, connecting stations via thin coaxial cable; maximum cable distance in one non-repeated segment is 185 meters.
10Base-5 - A variant of Ethernet, connecting station via thick coaxial cable; maximum cable distance in one non-repeated segment is 500 meters.
10Base-FL - A variant of Ethernet, connecting stations via fiber optic cabling.
10Bast-T - A variant of Ethernet, connecting stations via twisted pair cabling.
100Base-FX - A variant of Ethernet which runs on multi-mode or single mode fiber optic cabling at 100Mbps. This is one version of Fast Ethernet.
100Base-TX - A variant of Ethernet which runs on Category 5 unshielded twisted pair wiring at 100Mbps. This is one version of Fast Ethernet.
1000Base-CX - A variant of Gigabit Ethernet which runs on twinaxial cable.
1000Base-LX - A variant of Gigabit Ethernet which runs on multi-mode and single mode fiber optic cable at a 1330 um frequency.
1000Base-SX - A variant of Gigabit Ethernet which runs on multi-mode fiber optic cable at an 850 um frequency.
1000Base-T - A variant of Gigabit Ethernet which runs on unshielded twisted pair cable.
A
ACR (Attenuation to Crosstalk Ratio) - The difference between attenuation and crosstalk measured in decibels.
Amplitude - In communications, the distance between the highest and lowest points in a wave. The amplitude controls the strength, or volume, of the signal.
ANSI (American National Standards Institute ) - A U.S. standard body. ANSI is a member of the International Organization for Standardization (ISO)
ATM (Asynchronous Transfer Mode ) - A high-speed, connection-oriented switching and multiplexing technology for transmitting information across a wide area or local area network. ATM divides information into fixed-length cell capable of transmitting different types of traffic simultaneously, including voice, video, and data.
Attenuation - The progressive weakening of a signal as it travels away from its point of origin.
AUI (Attachment Unit Interface) - Defined in the IEEE802.1 specification as the interface between an Ethernet MAU and DTE. Basically, the way an Ethernet station connects to a transceiver sitting on a thick Ethernet Cable.
AWG (American Wire Gauge ) - A standard for determining wire size. The gauge varies inversely with the actual wire diameter.
B
Backbone - LAN or WAN connectivity between subtends across a high-speed network. Often applied to a high-speed campus network, such as ATM OC-12or GIGABIT Ethernet., that interconnects lower speed networks, such as ATM OC-3 or Fast Ethernet. Fiber optic cable is often used.
Balance - An indication of signal voltage equality and phase polarity on a conductor pair. Perfect balance occurs when the signals across a twisted-pair are equal in magnitude and opposite in phase with respect to ground.
Balanced Signal Transmission - Two voltages, equal and opposite in phase with respect to each other, across the conductors of a twisted-pair.
Balun - Balanced/unbalanced. An impedance matching device used to connect balanced twisted pair cabling with unbalanced coaxial cable.
Bandwidth - (1) The range of signal frequencies that can be carried on a communications channel. The capacity of a channel is measured in cycles per second, or hertz (Hz), between the highest and lowest frequencies. (2) Commonly, the carrying capacity of a digital translation facility, measured in bits per second (bps).
Baseband - A technique whereby digital input is directly applied to transmission media without the intervention of a modulation device. Baseband is generally in an environment with high bandwidth over a short distance. It is generally considered easier and more cost- effective than broadband. Ethernet, token ring, FDDI, and ATM generally used baseband.
Bend Loss - Increased attenuation in a fiber that results from the fibers being bent, or from minute distortions within the fiber.
Bonding - The permanent joining of metallic parts to form an electrically conductive patch that will assure electrical continuity and the capacity to conduct safely any current likely to be imposed on it.
bps (Bits per second) - The amount of data transferred in a second.
Bridged Tap - The multiple appearances of the same cable pair or fiber at several distribution points.
Bridging - A means of providing through connections between conductors or pairs that are terminated on connecting blocks. These through connections are commonly provided by means of individual metallic’ bridging” clips or multiple “ bridging” clips that are housed in a plastic insulator.
BroadBand - Characteristic of any network that multiplexes multiple, independent carrier signals onto a single cable. This is usually accomplished through frequency division multiplexing. Broadband technology allows several signals to coexist on a single cable; traffic from one signal does not interfere with traffic from another, since data is transmitted on a different frequency. Cable television uses broadband.
Bundled Cable - An assembly of two or more cables continuously bound together to form a single unit prior to installation.
Bus( liner bus) - A network topology in which all computers are connected by a single length of cabling with a terminator at each end.
C
Cabling - A combination of cables, wire, cords and connecting hardware used in the telecommunications infrastructure.
Campus Backbone - Cabling between building that share telecommunications facilities.
Channel - The end-to-end transmission patch connecting any two points at which application specific equipment is connected.
Cladding - In fiber-optic cabling, a layer of glass that surrounds the inner core and reflects light back into the core.
Coaxial Cable - (Coax) - Formerly common in Ethernet networks, coax comes in various types with different transmission characteristics. It is copper-based, with an inner conductor surrounded by an outer conductor, with insulation between that two, insulation between the two, insulation around the outer conductor, and a jacket. Coax is less flexible than twisted pair cable, but more resistant to EMI and physical breakage.
Cross-connect - A facility enabling the termination of cables as well as their interconnection or cross-connection with other cabling or equipment.
Crosstalk - The unwanted introduction of signals from one channel o pair to another.
D
DCE (Data Circuit-terminating equipment) - The designation given to equipment such as modems and multiplexes by the Electronic Industry of America (EIA). Differs from DTE (Data Terminal Equipment) in that it transmits data on pin3 and receives data on pin 2.
Decibel (dB) - A logarithmic comparison of power levels defined as ten times the base ten log of the ratio of input power to output power. One tenth of a bel.
Demarcation Point - The point inside your building (or on the campus premises) at which the phone company (or other service provider) is no longer responsible for network cabling or service.
Digital Line - A data or voice network interconnectivity medium that supports digital signaling.
D-Type - The standard connector used for RS232-C, RS423 and RS422 communication. It is most commonly used in 9,15 and 25-pin configurations.
DTE (Data Terminal Equipment) - The RS232-c Standard referring to equipment that transmits and/or receives data on a network. This standard typically applies to terminals, PCs, and printers.
Duplex - A Technique allowing bi-directional, simultaneous transmission along a channel. Generally referred to as full duplex.
E
EIA - Electronic Industries Association
EIA 568 - A commercial building wiring standard for voice and data communications developed in 1989 by EIA.
ELFEXT - (Equal Level Far-end Crosstalk) Crosstalk measured at the opposite end from which the disturbing signal is transmitted, normalized by the attenuation contribution of the cable or cabling.
EMI (Electromagnetic Interference) - Energy generated by outside sources, such as lighting systems and electric motors, which is received by cooper data/voice cable and interferes with transmission.
Ethernet - The most common layer-two protocol used in LANs. Ethernet is a 10Mbps CSMA/CD standard originally developed by Xerox to run on thick coaxial cabling. It has evolved and now runs primarily on twisted pair cabling.
F
Fast Ethernet - A version of Ethernet which operates at 100 Mbps. See 100Base-Tx and 100Base-FX.
Fiber Channel - A form of high-speed fiber optic transmission designed primarily for communications between mainframe computers, and between mainframe computers and high-speed peripherals such as disk drives. Sometimes used for general-purpose networking. Fiber Distributed Data Interface (FDDI)-A high speed networking technology based on fiber optics. The topology of FDDI LANs is dual-attached, counter-rotating Token Rings.
Fiber Optic Cable - A type of cable consisting of glass or plastic fibers that are used to carry light signals. Fiber optic cable supports transmission speeds up into the 100Mbps.
Fiber Optic Transmission - A communications scheme whereby electrical data is converted to light energy and transmitted through optical fibers.
Frame Relay - An ITU standard for the interface to a public frame-switching network designed to provide high-speed frame transmission with minimum delay across the wide area. It operates at layer two, and it used in public and private networks, gradually replacing X.25 and leased-line networks.
G
Gbps - Billions of bits per second.
Gigabit Ethernet - A variant of Ethernet which operates over multi-mode fiber optic cable, single mode fiber optic cable, or unshielded twisted pair, at 1,000 Mbps.
H
Half-Duplex - A communications method in which one end transmits while the other receives, then the process is reversed. This was common in wide area point-to-multipoint circuits, such as those used in many SNA networks. Head End-A central point in a broadband network that receives signals on one set of frequency bands and retransmits them on another set of frequencies. The head end is viewed as a central hub. Every transmission on a broadband network must go through the head end.
Horizontal Cabling - That portion of a building’s cabling system which extends from the wiring closets to the individual workstations, servers, telephones, and other devices. This is generally copper twisted pair cable.
Hub - The center of a star topology network or cabling system. Typically used in older Ethernet and token ring networks. A device connected to a hub receives all the transmissions of all other devices connected to that hub. Hubs are now being replaced in many cases by LAN switches.
Hybrid cable - An assembly of two or more cables, of the same or different types or categories, covered by one overall sheath.
Hybrid Network - A LAN consisting of a number of topologies and access methods. For example, a network that includes both token ring and Ethernet.
HZ (Hertz) - A measure of frequency or bandwidth.
I
IDC (Insulation Displacement Contact ) - A type of wire terminating connection in which the insulating jackets is cut by the connector when the wire is inserted.
IEEE (Institute of Electrical and Electronic Engineers) - A standards-making body responsible for implementing many standards, used in LANs, including the 802.x series.
IEEE 802.1D - See “Spanning Tree”
IEEE 802.1p - An IEEE standard for prioritizing time-critical flows and filtering multicast traffic to contain traffic in layer-two networks. The 802.1p header includes three bits for prioritization, allowing for eight priorities to be established.
IEEE 802.1Q - An IEEE standard for providing a virtual LAN capability within a campus network, used in conjunction with IEEE LAN protocols such as Ethernet and token ring.
IEEE 802.2 - A data link standard outlining how basic data connectivity over cable should be set up. Used with the IEEE 802.3, 802.4 and 802.5 standards.
IEEE 802.3 - The IEEE’s specification for Ethernet, including both physical cabling and layer-two protocol.
IEEE 802.5 - The IEEE’s specification for token ring, including both physical cabling and layer-two protocol.
IEEE 802.10 - The IEEE’s protocol for providing security in a metropolitan area network. A variant of 802.10 has sometimes been used to provide a virtual LAN service within a campus network, although this is now generally replaced with 802.1Q.
Insertion Loss - The amount of the signal that is lost (attenuation) as the signal passes through a connection or interface.
Internetwork - Two or more networks connected by bridges or routers
Intranet - The use of various Internet tools ands protocols, especially HTTP and HTML, within an organization.
K
Kbps - Thousands of bits per second.
L
LAN (Local Area Network) - (1) The network which interconnects all computing devices located within a single end user location; e.g., an integrated token ring/ ATM network covering an entire campus. (2) A single layer-two network, which may be connected to other such networks within an end user location; e.g., a single Ethernet segment. To avoid confusing the two definitions, Xylan commonly refers to the former as a “campus” network.
LED - Light Emitting Diode.
Link - An end-to-end transmission path provided by the cabling infrastructure. Cabling links include all cables and connecting Equipment and work area cables are not included as part of a link.
Local Exchange Carrier (LEC) - The local regulated provider of public switched telecommunications services.
M
Mpbs - Millions of bits per second.
MDF (Main Distribution Frame) - In a structured building wiring system, the central point for cabling throughout the building. Typically, multiple IDFs located in wiring closets connect to a central MDF.
MMJ (Modified Modular Jack) - A six-wire modular jack with the locking tab shifted off to the right side. Used in the DEC wiring system.
Modulation - The process of modifying a carrier signal to transmit information.
Multi-mode - A form of fiber optic cabling in which light in able to follow multiple paths as it traverses the cable. Less expensive, and with a lower maximum rate and distance, than single mode fiber optic cable.
Multiplex - To transmit two or more messages or message streams on a single channel, typically through the use of frequency-division multiplexing, time division multiplexing, or statistical time division multiplexing.
Multiplexer - A device used for division of a transmission facility into two or more subchannels, either by splitting the frequency band into narrower bands or by allotting a common channel to several different transmitting devices one at a time. Also known as a mux.
N
NEXT (Near End Crosstalk) - Signal distortion as a result of signal coupling from one pair to another at various frequencies.
Network - A number of interconnected systems that, typically, exchange information with one another and share resources that may be distributed among the systems.
NIC (Network Interface Card) - A physical plug-in module which goes into a workstation or server and provides the connection to a network.
Node - Any network device (such as a server, workstation, or router) that can communicate across the network.
P
Patch Panel - Connecting hardware that typically provides means to connect horizontal or backbone cables to an arrangement of fixed connectors that may be accessed using patch cords or equipment cords to form cross connections or interconnections.
Phase - The amplitude of a cyclic signal at a specific point in time.
Plant - The cables that connect computers together in a LAN.
Plenum - A compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system.
Propagation Delay - The amount of time that passes between when a signal is transmitted and when it is received at the opposite end of a cable or cabling.
POTS - Plain Old Telephone System
Protocols - The specifications that define procedures used by computers when they transmit and receive data.
Punch Down - A method for securing wire to a quick clip in which the insulated wire is placed in the terminal groove and pushed down with at special tool.
PVC (Poly-vinyl Chloride) - The material most commonly used for the insulation and jacketing of cable.
R
RFI (Radio Frequency Interference) - Noise created in the radio-frequency range.
Return Loss - Noise or interference caused by impedance discontinuities along the transmission line at various frequencies, Return loss is expressed in decibels.
Riser Cabling - That portion of a building’s cabling system which extends from the main distribution frame to the wiring closets. For data, this is often fiber optic cable. For voice, it is fiber optic cable if the PBX is distributed, and twisted pair copper cable otherwise.
RJ-11 - A standard connector commonly used to terminate voice connections.
RJ-45 - A standard connector commonly used to terminate data connections.
RS-232-C - An Electrical Industries Association (EIA) Standard for the physical interface between Data Terminal Equipment (DTE) and Data Circuit Terminating Equipment (DCE)
Router - A layer-three device responsible for making decisions regarding which of several paths network traffic will follow. To do this, it uses a routing protocol to gain information about the network, and algorithms to choose the best route based on several criteria (known as routing metrics). Routers interconnect subnets.
S
SC - A type of optical fiber connector. The SC utilizes the same 2.5mm ferrule as the ST, held in a housing that allows for “push-pull” insertion and removal of the connector of choice for data networks.
Signaling - The process of sending information over media.
Single Mode - A form of fiber optic cabling in which light follows a single path as it traverses the cable. More expensive, and with a higher maximum rate and distance, than multi-mode fiber optic cable.
SOHO - Small Office/ Home Office
Spanning Tree - A protocol specified in the IEEE 802.1 D standard which allows a network to have a topology that contains physical loops. Spanning Tree operates in bridges and switches. It opens certain paths to create a tree topology, thereby preventing packets from looping endlessly on the network.
Star - A network topology in which each node is connected to a central point.
Station Cabling - See “Horizontal Cabling”.
ST - A registered trademark of AT&T for their fiber optic connector. Originally, an acronym for “Straight Tip”.
STP (Shielded Twisted Pair) - Copper cable that includes one or more sets of cable pairs which have been molded into an insulating material and covered by a braided shielding conductor. STP offers better noise protection than unshielded twisted pair (UTP) but is much more expensive and more difficult to use. Commonly associated with early token ring networks.
Surge - A rapid rise in current or voltage, usually followed by a fall back to a normal level. Also known as transient.
T
TC (Telecommunications Closet) - Central location for termination and routing of on-premises wiring systems.
TIA(Telecommunications Industry Association) - An organization that sets standards, for cabling, pathways, spaces, grounding, bonding, administration, field testing and other aspects of the telecommunications industry.
Token ring - A network architecture standardized in IEEE 802.5 in which the devices on a ring transmit data while they are in possession of a token which passes from node to node continuously. Token ring operates at 4 or 16Mbps.
Topology - Can be either physical or logical. Physical topology describes the physical connections of a network and the geometric arrangement of links and nodes that make up that network. Logical topology describes the possible logical connections between nodes, and indicates which pairs of nodes are able to communicate.
TP-PMD - Twisted Pair Physical Media Dependent. ANSI X3T9.5 Committee’s proposed 100 Mbps over UTP Standard. Also referred to as CDDI (Copper Distributed Data Interface)
Transceiver - A device used in contention networks of resending and receiving data over the same network.
Transient - A high-voltage burst of electric current, usually lasting less than 1 second, occurring randomly.
Trunk Cable - Typically refers to a copper twisted pair backbone or vertical riser cable consisting of multiple groups of 25 pairs.
Twisted Pair - Insulated copper wires twisted together with the twists or lays varied in length to reduce potential signal interference between the pairs. They are usually bundled together and wrapped in a cable sheath. New data grade Unshielded Twisted Pair (Category 5) is specified for 100 Mbps transmission.
U
UTP (Unshielded Twisted-Pair) - A type of twisted-pair wire that has no metalized outer covering, shielding the pairs of wire. The pairs are typically covered with a plastic sheath.
USOC (Uniform Service Ordering Code) - A term originally used by the telephone company to specify installation of a standard modular jack.
V
VLAN (Virtual Local Area Network) - In a switched network, a logical collection of devices, such as all the workstations and servers with a particular IP subnet address, which are grouped into a broadcast domain.
W
WAN (Wide Area Network) - A network which covers a larger geographical area than a single end user location, and in which telecommunications links are implemented; normally leased from service provider(s).
3PThird
Third Party Testing, in Denmark
ISDN
Integrated Services Digital Network
ACR
Attenuation-to-crosstalk ratio
ISO
International Standard Organization
ADO
Auxiliary disconnect outlet
JTC
Joint technical committee
ADSL
Asynchronous Digital Subscribes Line
Kb/s
Kilobit per second
ANSI
American National Standards Institute
Km
Kilometer
ATM
Asynchronous transfer mode
KYS
Key telephone system
AWG
American wire gauge
LAN
Local area network
BD
Building distributor
lbf
Pounds force
BER
Bit Error Rate
LEC
Local exchange carrier
BFOC
Bayonet Fiber Optic Connector
LED
Light emitting diode
b/s
Bit per second
M
Meter
CD
Campus distributor
um
Micron; 0.000001; also micrometer
CDDI
Copper Distributed Data Interface
Mb/s
Megabits per second
CM
Common mode
MC
Main cross-connect
CP
Consolidation point
MDF
Main distribution frame
CPE
Customer premises equipment
MHz
Mega Hertz
CSA
Canadian Standard Association
mmr
Millimeter
dB
Decibel
MT-RJ
Mechanical Transfer Registered Jack
DD
Distribution device
NEC
National Electrical Code
EF
Entrance facility
NEMA
National Electrical Manufacturers Association
EIA
Electronics Industries Alliance
NEXT
Near-end crosstalk
ELFEXT
Equal level far-end crosstalk
NFPA
National Fire Protection Association
EMC
Electromagnetic compatibility
nm
Nanometer
EMI
Electromagnetic interface
PBX
Private branch exchange
EMR
Electromagnetic radiation
PVC
Polyvinyl chloride
ER
Equipment room
RF
Radio frequency
FCC
Federal Communication Commission
RMS
Rack mount space
FD
Floor distributor
SC
Subscriber connector
FDDI
Fiber Distributed Data Interface
ScTP
Screened twisted pair
ft
Feet
SOHO
Small office home office
FEXT
Far-end crosstalk
STP
Shielded twisted pair
FIPS PUB
Federal Information Processing Standard Publication
TIA
Telecommunications Industry Association
FTP
Foil twisted pair
TO
Telecommunications outlet
Gb/s
Gigabit per second
TP
Transition point
GHz
Giga hertz
TP-PMD
Twisted-Pair Physical Media Dependent
HC
Horizontal cross-connect
TPDDI
Twisted-Pair Distributed Data Interface
HVAC
Heating, ventilation and air condition
TSB
Telecommunications System Bulletin
Hz
Hertz
UL
Underwriters Laboratories Inc.
IC
Intermediate cross-connect
UPS
Uninterruptible power supply
IDC
Insulation displacement connection
USOC
Universal Service Order Code
IDF
Intermediate Distribution Frame
UTP
Unshielded twisted pair
IEC
International Electrotechnical Commission
WA
Work area
IEEE
Institute of Electrical and Electronic Engineers
| Fiber Optics Standards |  |
Description | |
| IEC 61755-3-2-2006 | Fibre optic connector optical interfaces - Part 3-2: Optical interface, 2,5 mm and 1,25 mm diameter cylindrical full zirconia ferrules for 8 degrees angled-PC single mode fibres | ||
| IEC 61755-2-2-2006 | Fibre optic connector optical interfaces - Part 2-2: Optical interface standard single mode angled physically contacting fibres | ||
| IEC 60332-1-3-2004 | Tests on electric and optical fibre cables under fire conditions - Part 1-3: Test for vertical flame propagation for a single insulated wire or cable - Procedure for determination of flaming droplets/particles | ||
| IEC 60332-1-2-2004 | Tests on electric and optical fibre cables under fire conditions - Part 1-2: Test for vertical flame propagation for a single insulated wire or cable - Procedure for 1 kW pre-mixed flame | ||
| IEC 60332-1-1-2004 | Tests on electric and optical fibre cables under fire conditions - Part 1-1: Test for vertical flame propagation for a single insulated wire or cable - Apparatus | ||
| IEC 61034-2-2005 | Measurement of smoke density of cables burning under defined conditions - Part 2: Test procedure and requirements | ||
| IEC 61034-1-2005 | Measurement of smoke density of cables burning under defined conditions - Part 1: Test apparatus | ||
| IEC 60754-2-1991 | Test on gases evolved during combustion of electric cables - Part 2: Determination of degree of acidity of gases evolved during the combustion of materials taken from electric cables by measuring pH and conductivity | ||
| IEC 60754-1-1994 | Test on gases evolved during combustion of materials from cables - Part 1: Determination of the amount of halogen acid gas | ||
| IEC 61300-3-30-2003 | Fibre optic interconnecting devices and passive components - Basic test and measurement procedures - Part 3-30: Examinations and measurements - Polish angle and fibre position on single ferrule multifibre connectors | ||
| IEC 61300-3-23-1998 | Fibre optic interconnecting devices and passive components - Basic test and measurement procedures - Part 3-23: Examination and measurements - Fibre position relative to ferrule endface | ||
| IEC 61754-4-2002 | Fibre optic connector interfaces - Part 4: Type SC connector family | ||
| IEC 61754-4-1-2003 | Fibre optic connector interfaces - Part 4-1: Type SC connector family - Simplified receptacle SC-PC connector interfaces | ||
| IEC 61753-1-2007 | Fibre optic interconnecting devices and passive components performance standard - Part 1: General and guidance for performance standards | ||
| IEC 61754-20 | Fibre optic connector interfaces - Part 20: Type LC connector family | ||
| IEC 61754-13 | Fibre optic connector interfaces - Part 13: Type FC-PC connector | ||
| IEC 61754-15 | Fibre optic connector interfaces - Part 15: Type LSH connector family | ||
| IEC 61754-3 | Fibre optic connector interfaces - Part 3: Type LSA connector family | ||
| IEC 61754-2 | Fibre optic connector interfaces - Part 2: Type BFOC/2,5 connector family | ||
| IEC 61754-18 | Fibre optic connector interfaces - Part 18: Type MT-RJ connector family | ||
| IEC 61753-2-1 | Fibre optic interconnecting devices and passive components performance standard - Part 2-1: Fibre optic connectors terminated on single-mode fibre for category U - Uncontrolled environment | ||
| TIA-604-4-B-2004 | Fiber optic connector intermateability standard, type FC and FC/APC | ||
| Telcordia GR-326-CORE | Generic requirements for singlemode optical connectors and jumper assemblies | ||
| BS EN60793-2-2004 | Optic fibers-part2:Product specifications general | ||
| TIA/EIA-455-1B | Cable Flexing for fiber optic interconnecting devices | ||
| TIA/EIA-604-10A | Fiber optic connector intermateability standard type LC | ||
| TIA/EIA-455-107A | Determination of component reflectance or link/system return loss using a loss test set | ||
| TIA/EIA-604-3A | Fiber optic connector intermateability standard type sc | ||
| GR-910-CORE | Generic requirements for fiber optic attenuators | ||
| GR-409-CORE | generic requirements for premises fiber optic cable | ||
| TIA/EIA-604-12 | fiber optic connector intermateability standand type MTRJ | ||
| TIA/EIA-604-12A | MTRJ | ||
| TIA/EIA-568-B.3 | optical fiber cabling components standard | ||
| TIA TSB125-2001 | guidelines for maintaining optical fiber polarity through reverse-pair positioning | ||
| IEC 61300-3-4-2001 | Fibre optic interconnecting devices and passive components - Basic test and measurement procedures - Part 3-4: Examinations and measurements - Attenuation | ||
| IEC 61300-3-6-2003 | Fibre optic interconnecting devices and passive components - Basic test and measurement procedures - Part 3-6: Examinations and measurements - Return loss | ||
| ICEA S-83-596-2001 | OPTICAL FIBRE PREMISES DISTRIBUTION CABLE | ||
| IEC 60793-1-31-2001 | Optical Fibres - Part 1-31: Measurement Methods and Test Procedures - Tensile Strength-First Edition | ||
| IEC 60793-1-32-2001 | Optical fibres - Part 1-32: Measurement methods and test procedures - Coating strippability | ||
| IEC 60793-1-30-2001 | Optical fibres - Part 1-30: Measurement methods and test procedures; Fibre proof test | ||
| IEC 60793-1-53-2001 | Optical fibres - Part 1-53: Measurement methods and test procedures - Water immersion | ||
| IEC 60793-1-20-2001 | Optical fibres - Part 1-20: Measurement methods and test procedures - Fibre geometry | ||
| IEC 60793-2-2003 | Optical fibres - Part 2: Product specifications - General | ||
| TIA-598-C-2005 | Optical Fiber Cable Color Coding | ||
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