|
|
|
|
Glossary of Telecom Terms
To find out more information on the products shown to the left,
visit our Search Price List page.
A | B | C |
D | E | F |
G | H | I |
J | K | L |
M | N | O |
P | Q | R | S |
T | U | V |
W| X | Y | Z
ACD (Automatic Call Dialing Distributor): A special facility of a PABX or Central Office switch
that automatically routes incoming calls to the next available or longest idle agent or attendant ina line hunt
group.
AGC (Automatic Gain Control): Electronic circuit which automatically increases the volume when someone is
speaking quietly and drops the volume when soneone is speaking bloudly, to keep the transmited signal
constant.
A-Lead: Control leads that come from 1A2 key telephone to operate features like flashing of lights to
indicate on line ringing etc.
Analog Single Line Station: An extension port on a PBX/KSU that will allow a standard household type
phone to interface with the system. (POTS)
BOM (Beginning ofMessage: A short electrical pulse proveded by a digital announcer when used in certain
4 wire E & M modes. The pulse alerts the PABX that the Beginning of a Message is coming.
Butt Set: A sophisticated one piece telephone used by technicians to diagnose telephone lines or
equipment.
Carbon Transmitter (Handset): The microphone of a telephone handset which uses carbon granules and a
diaphram. The diaphragm responds to voice and varies the pressure on the granules and hence, their resistance.
C.O./CO (Central Office): A main telephone office where switching equipment is housed and customer lines
originate. Also contains trunk line cannections to other Central Offices. A C.O. line is a phone line coming from
the Central Office and terminating at the user's premise.
Centrex: A name for an umbrella service offering of the local telephone company. Customers lease a portion
of the Central Office switch to create a centralized point of control and routing. In concept, Centrex is
providing similar features to a PABX>
CNG (CalliNG): 1100 Hz .5 second tone generated every 3.5 seconds by fax machines.
Contact Closure: Contacts that when "closed" connect a pair of wires together and disconnects the wires
when "open". A doorbell button is a simple example of a momentary contacty closure.
CPC (Calling Party Control (Disconnect Supervision)): A short break in the line current in the called party's
phone line when the calling party hangs up. Not available ob PABX's.
DID (Direct Inward Dialing): A feature allowing callers to directly reach a PABX extension without an
operator's assisstance.
Distinctive Ringing (Ringmate, Custom Ring, Identifying Ring Master): Different patterns of ringing that
allow a user to identify the source of the call, outside, or inside (intercom) or who the call is for. Usually two
burst or three burst with different durations.
DSL: Digital Subscribe Line.
DTMF (Dual Tone Multi-Frequency (Touch Phone)): Audible tones which cinform to North American Telephone
Standards. These are generated by push-button telephones to dial telephone numbers as well as to provide control or
data input to voice processing systems.
E Memory: See Non-Volatile.
E & M: The receive and transmit leads of the signaling system. An equipment signaling system
usually used in PABX applications with a digital announcer.
Earth Ground: A wire conductor that terminates in the earth for electrical purposes.
FCC: Federal Communications Commission.
Ground Start Line: A type of call signaling. In this scheme, when a call is routed to a subscriber, the phone
company will apply a ground signal on the TIP side of the line even before a ring signal is sent. By detecting this
signal, phone systems can immediately determine that the line is about to be in use, and avoid call
crashing.
Hook Switch Flash or Switch Hook Flash: A signal originated by momentarily depressing the switch hook on a
single line phone. Typically used for accessing C.O. or PABX featurers.
Hz (Hertz): Indicates the frequency (number of cycles per second) of alternating current such as ringing
voltage or Touch tone signals.
Intercept: To stop a telephone call directed to an improper telephome number, and redirect that call to
an operator or recording.
IC (Industry Canada formally DOC): The equivalent of U.S. FCC.
ISDN (Integrated Services Digital Network): An emerging international standard that defines interfaces
for simuutaneous voece and data transmission through a single channel over the public network.
ISDN Terminal Adapter: An interface between an ISDN line and a compurter. Often these provide 1 or 2
analog POTS output ports.
LED: Light emitting diode.
Loop Current: Current that flows from the C.O. when a telecom device goes off hook.
Loop Start Line (POTS): A type of calling signal that relies on a telecom device to allow DC current to flow
when it goes into an off hook condition. The C.O. or PABX senses this current and intercepts it as a request for
service.
MOH: Music on hold.
N.O./N.C.: Normally open/Normally closed contact.
"NO KSU": A phone containing all control functions normally associated with a KSU.
Non-Volatile E Memory: Memory that will not be lost from a power failure. Does not need battery
Backup.
OPX (Off Premise Extension): A telephone line from the phone system terminated in a different building
than the phone system.
PABX (Private Automatic Branch Exchange): Phone system used to switch telephones between extensions
and to outside lines. For incoming and outgoing (dial 9 calls).
PBX: See PABX.
POTS (Plain Old Telephone Service): See C.O.
Rack Mount: Equipment which is designed to mount in a standard steel frameworkconsisting of paraellel
pairs of steel channel verticals spaced 19" and drilled for mounting screws.
RAD/RAN Device: A Record/ANnounce device such as a Digital Announcer.
RAN Trunk/RAN Circuit: A Record/ANnounce trunk or circuit that connects the telephone sytstem to a
record/announce device.
REN (Ringer Equivalency Number): 1 REN = The energy to ring 1 Plain Old Telephone. The REN number can
be found on the FCC label on the device. The total ringer load on a line is equal to the sum of all the REN numbers
of all the telephone devices connected to the line.
Ring Back Tone: The sound you hear when the phone you call is ringing.
Ringdown Circuit: A circuit connecting 2 devices so that when one device goes off hook it automatically
rings the other device.
Ring Generator: A circuit producing AC voltage that is higher than 50 VRMS and has a frequency of 20 Hz.
Ring Signal: Same as Ringback.
Ring Trip: The Process of stopping the AC ring signal and connecting the voice path at the C.O. when the
ringing telephone is answered.
Ring Voltage: a 20 Hz AC voltage higher than 50V superimposed on the phone line to ring bells, activate
ring detectors in phone systems, faxes, modems, etc.
RMS(Root Mean Square): This simply a fancy way of describing the average voltage level of an audio signal.
RS232: An Electronic Industry Association (EIA) standard that defines a computer interface for connecting
serial communication devices such as printers and modems.
66 Block: A terminal block where up to 4 sets of up to 25 pairs of wire can be interconnected. The installer
uses a special "punch down" tool to connect the wires.
SLT: Single Line Phone.
SOHO (Small Office/Home Office): An acronym for a new class of employment where the employee may
be performing part or all of their work at nome in a snall office set up.
Subscriber Line: The telephone line connecting the local Telco Central Office to be the customer' s
telephone instrument or telephone system.
Talk Battery: DC voltage supplied by the C.O. to the subscriber' s loop to operate the telephone equipment.
Telco: Local Telephome Company.
Terminal Device: Telephone, phone system, fax, modem, etc. capable of terminating an analog phone line.
Trunk: A telephone communication path or channel between two points. One usuallly being a Central Office.
Trunk Port: An input on a PABX or KSU that is used to interface the system with C.O. lines.
UCD (Uniform Call Distributor): An ACD programmed to distribute calls to agents or representatives on a
basis other than the next available. Each pereson in the group receives the same number of calls.
UPS (Uninterruptible Power Supply): Provides power to your phone equipment, computers, etc. in the
event of a commercial power failure.
VOX (Voice Operated eXchange): Your voice starts it. When you stop speaking its stops.
|
|
