The key to
understanding any technology is understanding the language of
the technology – the jargon. This page is an overview of cabling
jargon to introduce you to the language of the technology and
help you understand what you will be reading in this section. We
suggest you read this section carefully to help your
understanding of the rest of the pages and refer back to it when
you encounter a term that you do not
What is Premises Cabling?
By premises cabling, we mean the cabling used inside buildings
(and in restricted geographic areas like campuses or among
business facilities) that follows industry standards. Mostly we
are refering to structured cabling systems defined by TIA-568 or
ISO/IEC 11801 and related standards that are used for
LANs, telephone systems and even other systems adapted to
structured cabling like CCTV, security or building management.
Other systems that depend on cabling such as security and
building control are migrating to structured cabing for its
widespread availability and predictability.
call it lots of things:
an overview of the basic jargon used in cabling.
begin with, what do we call this technology of cabling?
VDV (for voice/data/video) cabling
Premises (e.g. indoor) cabling
Structured cabling (from the standards)
Low voltage cabling (less than power cables)
Limited energy cabling (mostly harmless)
Teledata cabling (a made-up word from telecommunications and
Datacom cabling (an abbreviated version of data communications)
most people call it"premises cabling" for its application or
"structured cabling" after the "568" standard.
cabling is the infrastructure for telephone and LAN
connections in most commercial installations and even in
some modern homes. It's also used for fire alarms, building
management, audio and video.
Cabling is the standardized achitecture and components for
communications cabling specified by the EIA/TIA TR42
committee and used as a voluntary standard by manufacturers
to insure interoperability.
cabling is based on a number of industry standards -
voluntary interoperability standards - developed by
manufacturers who want their products to work together. They
meet in committees several times a year and decide on the
specifications of their products. These common specs mean
that equipment will work on any cabling system that follows
the standards and most cabling components can be
interchanged without adversely affecting performance.
In the US, Electronics Industry Alliance/Telecommunications
Industry Association (TIA),
an industry trade association that creates voluntary
interoperability standards for the products made by member
companies. Worldwide standards rely on ISO
568: The main standard document for structured cabling,
usually referred to as simply "568." It is now on the "C"
revision, published in 2009. Worldwide, ISO/IEC 11801 is
approximately the same as TIA-568. More.
569: Covers pathways and spaces. Defines the "telecom
closet" or telecom room as it is now called. (ISO/IEC
570: For residential cabling.
606: cabling system administration (documentation) (ISO/IEC
607: Grounding and bonding
are not code! They are voluntary interoperability
specifications. However every installation must be compliant
to local building codes for safety!
(National Electrical Code): written by NFPA
(National Fire Protection Assn.) this code sets
standards for fire protection for construction and is a
legal requirement in most cities.
Cabling Architecture (TIA-568)
Traditional structured cabling (above)
defined in TIA 568 and adopted by ISO/IEC 11801 includes UTP
copper cabling and fiber optics, including centralized fiber
optics. These standards are updated to recognize passive optical
LANs (POLs) based on fiber to the home (FTTH) technology (below)
using fiber optic passive splitters instead of electronic
(optical LAN) using PON (passive optical network) from FTTH
(fiber to the home)
listed her are the traditional terms used since the beginning of
structured cabling, but a new
set of terminology is being introduced. See below or the
changed these terms to the ones in the diagram below but the
former terms are still widely used because they are well
understood and descriptive. Here
are the new terms.)
Closet (TC): The location of the connection between
horizontal cabling to the backbone. Now often called
"Telecom Room" to imply it's usually bigger than a closet!
Cross-Connect (MXC): The old telco term for the location of
the main electronics in a building. LAN people may call it
the equipment room
Cross-Connect (IXC) : A room in between the TC and MXC where
cables are terminated
Area Outlet: The jack on the wall which is connected to the
desktop computer by a patchcord
Panel: A rack or box where cables are terminated - usually
in 110 punchdowns and interconected with patchcords
Cabling: The connection from the telecom closet to the work
area outlet (desktop)
Cabling: The cabling that connects all the hubs in telecom
closets or MXCs together
(Permanent Link): The installed cable plant from work area
outlet jack to the patch panel in the telecom closet
The cable plant including the link plus patchcords on either
end to connect the communications hardware
A short length of stranded cable with a RJ-45 plug on either
end, used to connect hardware to the link or to connect
cables in a Patch Panel. Also a short fiber optic cable use
hook: A hook shaped like the letter J used to suspend cables
Semiflexible rod used to retrieve cables or pull line
Types Of "Low Voltage" Copper Cable.
more information on fiber optic cabling, see the FOA
Online Fiber Optic Reference Guide.
Unshielded twisted pair cable, most commonly comprised of 4
twisted pairs of copper conductors, graded for bandwidth as
"Levels" (from Anixter) or "Categories" (EIA/TIA 568).
Legacy analog phone systems (POTS or plain old telephone
systems) used multipair UTP cables with 25, 50, 100, 200 or
3,4,5, 5e, 6, 6A, 8: Ratings on the bandwidth performance of
UTP cable, originally derived from Anixter's Levels program.
Category 5e (enhanced) is rated to 100MHz. Cat 6 standards
for UTP are specified at up to 200 MHz. Cat 6A (augmented)
up to 500 MHz has recently been ratified. Cat 7 is also
discussed for the future, but is only standardized as "Class
F" in Europe, not the US.
Cat 8 is a new short length cable proposed for data center
connections of servers and switches.
"Categories" called "Classes" in worldwide standards like
ISO and IEC. Cables rated Cat 5 or higher are limited
to 4 pairs.
Screened Twisted Pair, a UTP cable with an overall foil shield
to prevent interference.
typical Cat 6 cable is shown below.
Shielded twisted pair, specified by IBM for Token Ring
networks and offered by some vendors in higher performance
versions than UTP.
fiber carries signals as pulses of light over thin strands
of glass or plastic instead of copper wire.
optical fiber: larger core fiber used for short, relatively
low speed links (~<10G)
optical fiber: small core fiber used for longer distance
linkes with almost unlimited bandwidth.
optical fiber (POF) large core plastic fiber used for short,
relatively slow links.
A type of cable that uses a central conductor, insulation,
outer conductor/shield, and jacket; used for high frequency
communications like CCTV (closed circuit TV) or CATV
(community antenna TV or cable TV). Coax is not included in
TIA-568 but is included in TIA-570 for home use.
75 ohm coax used for video. RG-6 is the standard for CATV,
RG-59 is used on some short CCTV networks.
50 ohm coax used for "Thinnet" Ethernet.
Hybrid fiber-coax CATV network combines coax and optical
connectors for UTP are also standard - used on every cable
for Cat 3, 5, 5e, 6, but must be rated for the same
performance level, e.g. Cat 6 hardware on Cat 6 cable.
The popular name of the modular 8 pin connector used with
UTP cable in structured cabling systems. It is used
erroneously, as a connector is only really an RJ-45 if it is
terminated with USOC pinout for plain old telephone
The receptacle for a modular plug like the modular 8
pin connector, often used in large quantities in patch
panels. (Left in the photo above)
Crosstalk: Crosstalk from one pair in a cable to the equivalent
pair in another cable, a problem with Cat 6A.
The connector on the end of UTP cable. (Right in the photo
A connecting block that terminates two cables directly, most
often used for connecting incoming multipair cables to 4
pair cables to the desktop but occasionally for cross
connecting 4 pair cables. 110 blocks are most popular for
LANs, 66 blocks for telco, but some installers use BIX or
Below - 66 blocks on the left, 110 blocks on the right:
installing the cables, they must be tested. Every cable,
including Cat 3 for telephones, must be tested for wiremap,
but cable certifiers will test for all the
parameters listed below. A third type of tester, called a verifier,
tests the cabling to see if it will transmit date for
specific networks like Gigabit Ethernet.
All eight wires must be connected to the correct pins, and
the test is called a wiremap test.
The length must be less than 90 m for the permanent link and
less than 100 m for the channel
The reduction in signal strength due to loss in the cable.
Near End Cross Talk, or the signal coupled from one pair to
another in UTP cable.
Attenuation to crosstalk ratio, a measure of how much more
signal than noise exists in the link, by comparing the
attenuated signal from one pair at the receiver to the
crosstalk induced in the same pair
Loss: Reflection from an impedance mismatch in a copper
Equal level far end crosstalk; crosstalk at the far end with
signals of equal level being transmitted.
Delay: The time it takes a signal to go down the cable.
Loop Resistance: The DC resistance of the cable in ohms.
Skew: The maximum difference of propagation time in all
pairs of a cable.
Sum Next: Near end crosstalk tested with all pairs but one
energized to find the total amount of crosstalk caused by
simultaneous use of all pairs for communication
Sum ElFEXT: ELFEXT for the sum of the other 3 pairs on the
Optic Cable Testing
optical fiber is much easier. One need only tests
polarity/continuity and the loss from one end to the other,
as bandwidth or frequency response is not generally an issue
for premises cabling. More
on fiber testing.
LAN Electronics That Makes It All Work Over The Cabling As
The electronic box that connects to all the horizontal
cables which are them connected by backbone cabling,
enabling any PC to talk to any other
A device like a hub but connects any two devices directly,
allowing multiple connections simultaneously
A device that connects two or more sets of network cables
A smart switch that connects to the outside world
A 10, 100 or 1000 Megabit per second local area network
(LAN) that is by far the most popular LAN. Ethernet::
A local area network (LAN) that is by far the most popular
LAN. Versions exist for transmission from 10Mb/s to
100Gb/s. All versions of Ethernet also have fiber optic
connection standards. See
the chapter on networks.
versions of Ethernet also have fiber optic connection
over Ethernet (PoE): The IEEE 802.3 Ethernet standards
committee has established standards for powering devices using
UTP cabling. The original intent was to use spare pairs in
10/100 Ethernet links to power devices like wireless access
points or VoIP phones but was expanded to use all pairs. The
name was not trademarked so it is now used for a number of
applications using UTP cabling that includes non-standard
applications like powering lights in offices as well as
network attached devices.
Is NOT Wireless
LANs today include wireless access points. Wireless is by no
means wireless, as it requires wiring to connect it to the
network. It merely replaces patchcords with a wireless link
to allow roaming within a limited area. Wireless requires
many access points connected (over wire or fiber) into the
is the popular name for IEEE 802.11 standard used by most
portable computers and many other mobile devices.
(IEEE 802.15) is a limited distance network for consumer
devices. It has been used to connect a wireless printer or
mouse to a PC, wireless headsets to cell phones and stereos,
cell phones to cars for hands-free operation, digital
cameras to printers, etc.
(IEEE 802.16) is a further development of wireless
network technology that expands the data capacity of
wireless and it’s distance capability.
optics: Testing is done with visual tracers/fault
locators, optical loss test sets and OTDRs. Here
is more information on fiber testers.
Equipment and Tools For Cabling:
multimeter: A simple tester that measures if the cable is
shorted and whether or not it is open
Mapper: Checks each wire to make sure they are terminated in
the correct order
Certification Tester: Tests everything, wiremap, length,
attenuation and crosstalk in one connection, gives you a
Verification Tester: A device that runs network signals over
installed cabling to see if the cabling can transmit network
data without error.
Time domain reflectometer, a testing device used for copper
cable that operates like radar to find length, shorts or
opens, and impedance mismatches
comprehension with the section quiz
Cabling Website Contents
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of Premises Cabling and Standards
Power Over Ethernet.
Installation VHO 66
Cable VHO Coax
Optics in Premises Cabling
of Contents: The FOA Guide