ACD– Automatic Call Distributor – A device for distributing many calls uniformly among a group of agents
or operators. The ACD pays attention to real time traffic load and other factors like which agent has been the
busiest or idle the longest, to evenly distribute call traffic to the agents (also see UCD).
ADA – Americans with Disabilities Act – Legislation passed in 1992 to assure equal building access for
the disabled, which also included equal access to emergency assistance in the event of an elevator emergency.
AGC – Automatic Gain Control – Electronic circuit which automatically increases the volume when someone
is speaking quality and drops the volume when someone is speaking loudly, to keep the transmitted signal
A-Lead -Control leads that come from 1A2 key telephone to operate features like flashing of lights to indicate a busy, holding or ringing line.
Analog Single Line Station – An extension port on a PABX / KSU that will allow a standard household type phone to interface with the system. [POTS]
API – Application Programming Interface: An interface provided by a software application to allow communication by other programs. This interface allows for requests for service to be made by other computer programs, and/or to allow data to be exchanged between computer systems.
ATA – Analog Telephone Adapter – Analog Telephone Adapter, allows user to connect telecom device to their LAN, WAN or internal (See FXO, FXS).
AWG– American Wire Gauge – The higher the AWG number the thinner the wire.
BOM – Beginning of Message – A short electrical pulse provide by a digital announcer when used in certain 4 wire E&M modes. The pulse alert the PABX that the Beginning of a Message is coming.
BSS – Business Support Systems: Business support services include services like billing, order entry, provisioning, order fulfillment and order activation. These are the systems that support service level agreements.
BUTT Set: a sophisticated, one piece, telephone used by technicians to diagnose telephone lines or equipment.
Call Progress Detection (Analysis) – A feature of some terminal devices that allows the Terminal Device to detect when a call has been answered ,so the device can play a recorded announcement to the person that answered.
Carbon Transmitter (Handset) – The microphone of a telephone handset which uses carbon granules and a diaphragm .The diaphragm responds to voice the pressure on the granules and hence, their resistance.
Cat 5E – This is a performance category for 8 conductor twisted pair wire. It defines the maximum data rate that a cable can handle.
CD Quality – Digital audio utilizing 16 bits of resolution at a sampling rate of 44.1K, which is the same as audio CD’s. Better sounding than other compressed formats such as MP3.
C.O/CO – Central Office – A main telephone office where switching equipment is housed and customer lines originals. Also contains Trunk line connections to other Central Offices. A C.O, line is a phone line coming from the Central Office and terminating at the user’s premise.
Central Station Monitoring – Service provide to monitor security system and emergency phones 24 hours a day. Often uses a high speed DTMF communication format to automatically identify where the call is coming from.
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. In some areas , also known as Centron, Cenpac, or Plexar.
CLEC – Competitive Local Exchange Carrier: A telecommunications provider company (sometimes called a “carrier”) that competes with other, already established carriers (generally the incumbent local exchange carrier).
CMOS – “Complimentary, Metal Oxide Semiconductor” – When used for the images sensor in video cameras it allows a wide operating temperature range with high reliability.
CNG • CalliNG – 1100Hz .5 second tone generated every 3.5 seconds by fax machines.
Codec – COmpressor-DECompressor, COder-DECoder, or ‘Compression/DECompression: A device or program capable of performing Encoding and Decoding on a data stream or signal. CODECs can also be used to compress and decompress data to allow for smaller data file transmission.
Contact Closure – Contacts that when “close “ connect a pair of wires together and disconnect the wires when “open” .A doorbell button is a simple example of a momentary contact 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 on most PABX’s.
CTI – Computer Telephony Integration: Technology that allows interactions on a telephone and a computer to be integrated or coordinated. CTI encompasses all contact channels (voice, email, video, fax etc.)
CRM – Customer Relationship Management: The group of systems and practices (methodologies, strategies, software and web-based capabilities) that encompass a business’s management of its customers.
Demarcation Point (DMARC) – Typically the point at which the phone line enters the building. The telephone company is responsible for all writing up to this point.
DISA – Direct Inwards System Access
DID – Direct Inwards Dialing is a feature allowing callers to directly reach a PABX extension without an operator’s assistance. Like having private phone numbers ringing to specific extensions.
Distinctive Ringing (also known as 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 Subscriber Line – High Speed digital data on standard two conductor voice grade telephone wiring. Allows high speed Internet access and telephone calls to take place simultaneously.
DSL Filter – Filter designed for DSL lines that prevents the normal telephones from hearing the high speed digital data and interfering with the data.
DTMF – Dual Tone Multi-Frequency (Touch Tone) – Audible tones which confirm to North America Telephone Standards. These are generated by push-button telephone numbers, as well as to provide control or data input to voice processing systems. Especially significant in the operation of Viking automated attendants and fax/data line sharing devices.
E911 – Enhanced 911: E911 services connect VoIP services to the existing 911 infrastructure. This allows for a VoIP emergency call to provide the same emergency-relevant location information that traditional telephony provides.
E&M Control /4 Wire E&M – An equipment signaling system usually used in PABX applications with
a digital announcer. This interface control scheme is standard equipment on most Viking announcers .
Earth Ground· A wire conductor that terminates in the earth for electrical purposes.
EMS – Element Management System: An element management system manages one or more of a specific type of network elements (NEs). In relation to hosted VoIP, the term is often used in describing delegated administration functions.
FCC– Federal Communications Commission
Facility Code· A 3 digit number that each Proxy Card contains in order to provide greater security. Usually the cards used at a given building all have the same facility code.
Fiber Optic Modems – Devices to extend a telephone link on fiber optic cable.
FXO – An analog input RJ·11 port just like a POTS trunk input on a PABX or key system. An FXO port
receives talk battery and ring voltage.
FXS – An analog output RJ-11 just like a station port on a phone system or PABX extension. It provides
Talk Battery, dial tone, and Ring Voltage.
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 features.
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 on improper telephone number, and redirect that call to on
operator or recording.
Industry Canada – Is the equivalent of U.S. FCC.
IP Trunking – Internet Protocol Trunking: a VoIP trunk gateway is an interface that facilitates the use of plain old telephone service (POTS) equipment, such as conventional phone sets and fax machines, with a voice over IP (VoIP) network. Commercially manufactured VoIP trunk gateways take the form of self-contained units (boxes) or circuit cards. The number of ports for POTS devices varies, depending on the intended application (small business, medium-sized business, or enterprise). The VoIP trunk gateway connects subscribers to the VoIP network without involving operators or incurring telephone company toll charges. The VoIP service provider establishes its own schedule of rates, if applicable, for local and longdistance calling.
ISDN – Integrated Services Digital Network· An emerging international standard that defines
Interfaces for simultaneous voice and data transmission through a single channel over the public network.
ISDN Terminal Adapter – An interface between an ISDN line and a computer. Often these provide 1 or
2 analog POTS output ports.
IVR – Interactive Voice Response: A computerized system that allows a person to select an option from a voice menu or otherwise interface with a computer system by speaking.
KSU • Key Service Unit – A central control cabinet serving many multi -button key telephones. Contains
equipment which enables the user to pick up and hold PABX or Central Office lines and provide Hashing
line, steady, busy, and wink hold signals. Dial intercom service is also an option.
LED• Light Emitting Diode.
Loop Current –[typically 20 to 50 m A] Current that How, from the C.O. when a telecom device goes off
Loop Start Line – 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. Also known as “POTS”.
Loud Ringing – A tone sent over a paging system that is typically triggered by Ring Voltage or a dry
MOH – Music On Hold
NAT – Network Address Translation: A process in which the source or destination of an IP packet is re-written as it passes through a firewall or router. This is usually done to allow multiple hosts behind a firewall or router to access the Internet via a single public IP-address
Night Ringing -The some as Laud Ringing, but usually disabled during the day or “normal business”
N.O./N.C. – Normally Open /Normally Closed Contact.
“No KSU” – A phone containing all control functions normally associated with a KSU,
thus not requiring a KSU.
Non-Volatile E2 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.
Page Code – An access code of a PABX that allows users to access the paging equipment to voice page.
Page Port – A 600 ohm audio output of a PABX intended to connect to an external paging amplifier.
Page Trigger – A signal provided to an amplifier to automatically switch the amplifiers input or mute
Background music during a page. Typically a “dry Contact Closure, but in some cases can be a 5 volt
DC or 12 volt DC trigger voltage.
PBX – (See PABX) .
PCB – Printed Circuit Board.
POTS – Plain Old Telephone Service (See C.O., Analog Single Line Station, loop Start line).
Phono (RCA Plugs – Shielded cable and connector arrangement is primarily used for row level audio or video connections.
Plexor· (See Centrexl
Proxy Card – A credit card sized cord that identifies itself when within close proximity of a reader. Cord “swiping” is not necessary. The card contains a 3 digit Facility Code, a 5 digit Internal card number and a 5 digit External Printed number, that may or may not match the Internal number.
Proxy Card Reader – A device used to read the data from a Proxy Card. The Proxy Card can be read when held within a few inches of the reader.
Rack Mount – Equipment which is designed to mount in a standard steel framework consisting of parallel
pairs of steel channel verticals spaced 19″ and drilled for mounting screws.
PSTN – Public Switched Telephone Network: The world’s public circuit-switched telephone networks. The PSTN is largely governed by technical standards created by the International Telecommunication Union.
RAD/RAN Device·-Record/Announce Trunk or Circuit -. a device such as a Digital Announcer.
RAN Trunk!RAN Circuit – Record/Announce Trunk or Circuit – Connects the telephone system 10 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.
Rf – Radio frequency- Electromagnetic waves operating between 10KHz and 3 MHz propagated without guide (wire or cable) in free space.
RF Choke· – A device intended to prevent RF waves from entering a wire or cable.
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 – (See Ring Voltage) A circuit producing AC voltage that is higher than 50 Volts and has a frequency of 20 HZ.
Ring Signal – (See Ring Voltage)
Ring Trip – The process of slopping 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 50 Volts RMS superimposed on the phone line to ring bells, activate ring detectors in phone systems, faxes, modems, etc.
RJ·11. RJ·14, RJ·21X, RJ·25 – Request DOD# 839
RMS – Root Mean Square This is simply a fancy way of describing the overage voltage level of an audio signal or Ring Voltage.
RS232 An Electronic Industry Association (EIA) standard that defines a computer interface for connecting serial communication devices such as printers and modems.
SBC (Session Border Controller) – A device used in VoIP networks. SBC’s are put into the signaling and media path between calling and called party. The SBC acts as if it were the called VoIP phone and places a second call to the called party. This means that both signaling traffic and media traffic (voice, video etc) cross the SBC. With that capability, SBC’s can function as firewalls, protocol transcoders, bandwidth managers, etc.
Session Initiation Protocol Trunking (SIP)– SIP provides IP-based voice services from a carrier, which seamlessly integrates with an organization’s local IP telephony solution. It provides better scalability than traditional PRI-based voice services. For example, a PRI circuit today is limited to just twenty-three B-channels. That’s equal to twenty-three concurrent phone calls. For medium and large businesses, with high call volumes, the only solution is to purchase several PRI circuits. With SIP Trunking, the number of channels available is limited only by the bandwidth of your circuit. Using MPLS or MOE services to support your SIP Trunking means a higher number of channels using only one circuit.
UM – Unified Messaging: The integration of email, fax, voice, video, etc. into a single in-box, accessible from a variety of different devices. Unified Messaging generally integrates telephone-based voice mail and is accessible via conventional or cellular phone
VPN – Virtual Private Network: A private communications network usually used within a company or group of companies to communicate over a public network. VPNs are typically encrypted with various grades of cryptography
XML – Extensible Markup Language: A W3C-recommended general-purpose markup language for creating special-purpose markup languages, capable of describing different types of data. In other words, XML is a method of describing data that is primarily used to facilitate data sharing across different systems. Programs can modify and validate documents based in XML without prior knowledge of their form.