Installation manual

RJ Registered Jack. RJs are telephone and data
jacks/applications registered with the FCC. Numbers,
like RJ-11, RJ-45, etc. are widely misused in the
telecommunications industry. A much more precise
way to identify a jack is to specify the number of posi-
tions (width of opening) and number of conductors.
Example: “8-position, 8-conductor jack” or “6-position,
4-conductor jack”.
S
Series Wiring See Daisy Chain.
Service Loop When a device is terminated to the wire
in the communications outlet, a fair amount of “slack”
should be left on the wire and wound in the box to
accommodate future trimming when devices are
changed out.
Splice The joining of two or more cables together by
connecting the conductors pair-to-pair.
Standards Agreed principles of protocol. Standards
are set by Committees working under various trade and
international organizations.
Star Wiring/Star Topology See Home Run.
Structured Media Center Leviton’s central distribu-
tion center for structured cabling. Also known as an
SMC.
Surge Suppression The prevention of voltage surges
from reaching and damaging electronic equipment
T
T1 A standard for digital transmission in North
America. A digital transmission link with a capacity of
1.544 Mbps (1,544,000 bits per second.) T1 lines are
used for connecting networks across remote distances.
Bridges and routers are used to connect LANs over T1
networks.
Talk Battery The DC voltage supplied by the central
office to the subscriber’s loop, which allows voice con-
versation.
TCP/IP A set of protocols developed by the
Department of the Defense to link dissimilar computers
across many kinds of networks.
Telco An Americanism for TELephone COmpany.
Ten Base-T See10Base-T at end of Glossary.
Terminate To connect a wire conductor to something,
typically a piece of equipment.
TIA Telecommunications Industry Association. A trade
organization of manufacturers which sets standards for
use of its member companies. Formerly fell under the
umbrella of EIA, (Electronic IndustriesAlliance). See
www.tiaonline.org.
Tip 1.†The first wire in a pair of wires. (The second
wire is called the “ring” wire.) 2.†A conductor in a tele-
phone cable pair which is usually connected to positive
side of a battery at the telco. It is the phone industry’s
equivalent of Ground in a normal electrical circuit. See
Ring.
Tone Dial A push-button telephone dial that makes a
different sound (in fact, a combination of two tones) for
each number pushed. The technically correct name for
tone dial is Dual Tone Multi Frequency, or DTMF.
Token Ring A ring topology for a local area network
(LAN) in which a supervisory frame, or token, must be
received by an attached terminal or workstation
before that terminal or workstation can start transmit-
ting. The workstation with the token then transmits and
uses the entire bandwidth of whatever communica-
tions media the token ring network is using. A token
ring can be wired as a circle or a star, with the work-
stations wired to a central wiring center, or to multiple
wiring centers. The most common wiring scheme is
called a star-wired ring. Whatever the wiring, a token
ring LAN always works logically as a circle, with the
token passing around the circle from one workstation
to another. The advantage of token ring LANs is that
media faults (broken cable) can be fixed easily, since
it’s easy to isolate the faults. Token rings are typically
installed in centralized closets, with loops snaking to
served workstations.
Topology As in network topology. The geometric phys-
ical or electrical configuration describing a local commu-
nication network; the shape or arrangement of a system.
The most common topologies are the bus, ring, and star.
TP-PMD Twisted Pair Physical Media Dependent.
Technology under review by the ANSI X3T9.5 working
group that allows 100 Mbps transmission over twisted-
pair cable.
Twisted Pair Two insulated copper wires twisted
around each other to reduce induction (thus interfer-
ence) from one wire to the other. The twists, or lays, are
varied in length to reduce the potential for signal inter-
ference between pairs. Several sets of twisted pair
wires may be enclosed in a single cable. In cables
greater than 25 pairs, the twisted pairs are grouped
and bound together.
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Installation Manual
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APPENDIX A
Glossary
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© Copyright 2001` Leviton Manufacturing Co., Inc.