Call accounting · Reference

Telecommunications glossary

Plain-English definitions for the acronyms and jargon you'll meet in PBXs, call accounting and the wider telephony world — from ACD to XML.

50 terms ·Search or jump by letter ·Marked up with schema.org DefinedTermSet

A

Abandoned call
A call that has been terminated before being answered or while on hold. Depending on the telephone system the reason may be displayed:
  • All busy — all phone lines or all extensions are busy.
  • Busy — the number dialled was busy.
  • Group — call abandoned while on a queue or other group.
  • Hangup — call abandoned while in progress.
  • Ringout — the call rang and was never answered.
  • Vacant — the number doesn't exist.
  • Other — reason can't be determined or wasn't supplied.
Account code
A code entered into a telephone handset before, during or after a call. The code is associated with the call in CDR or SMDR data and can indicate the customer or call type, allowing the call to be charged to a customer account — for example, in a law office.
ACD Automatic Call Distribution
The ACD manages telephone queues, so that the call that has been waiting the longest is answered first. Certain inbound numbers can be given higher priority.
ANI Automatic Number Identification
Allows the receiver of a telephone call to display and record the phone number that originated the call.
Authorisation code
A code entered into a handset to change the class of service for a phone call — for example, permitting an outgoing or long-distance call.
Auto Attendant
A virtual receptionist that allows calls to be transferred to an extension without human intervention — typically via a simple menu ("press 1 for sales, press 2 for support").

B

BT Busy Tone
The sound made by a PBX handset when the called party is busy.

C

Call accounting
An application that collects metadata about telephone usage and assigns call costs for later reporting. Also known as call analytics, call logging or call reporting.
Caller ID
Displays the calling party's number or name before the call is answered.
CDR Call Detail Record
Information a PBX, key system or other telephone exchange makes available to a connected device (typically a computer). It describes each call as it happens — including time and duration.
CO Central Office
A call generated by a PBX — such as when an extension is on permanent diversion. The call will often show in reports as the extension "CO".
CSV, .csv Comma Separated Values
A file with fields of each record separated, or delimited, by commas. Each record is separated by carriage-return and new-line characters (\r\n). A .csv file opens directly in Microsoft Excel.

D

DID / DDI Direct Inward Dialing / Direct Dialing In
A way to directly dial a person or hunt/ring group even though they're an extension on a large PBX. A DDI phone number is the number a caller dialled to reach your PBX.
DNIS Dialed Number Identification Service
Indicates the number that was originally dialled, which may be different than the resulting end phone number due to call forwarding.

E

Extension
A PBX typically has a number of telephone handsets. In addition, it may have many extensions that aren't visible to the user — hunt groups, queues and other virtual extensions used internally by the PBX.
External call
Calls made between a telephone outside your business and a telephone inside your business that use a trunk.

H

Handset
A station is the telephone extension — for example extension 100 or 101. See Station.
Hunt group
A group of telephone extensions tied to a single telephone number.

I

Incoming / inbound call
Calls made into your PBX from the public telephone network.
Internal call
Calls made from one extension to another.
ISDN Integrated Services Digital Network
A set of standards for the simultaneous transmission of data, video, voice and other services over the standard telephone network.
IVR Interactive Voice Response
Technology that lets people interact with a computer over the phone by pressing numbers on the keypad or using voice commands.

K

KTS Key Telephone System
Small business telephone systems used where there are 2-100 stations and a large number of internal intercom calls relative to inbound or outbound calls.

L

Line
See Trunk.

M

Metadata
A set of information that describes other data. For a telephone call, the metadata describes the number dialled, how long it took to be answered and the call's duration.
Multipart call
Calls that involve more than one extension — for example, a call transferred from one extension to another.

O

Outgoing / outbound call
Calls made from an extension on your PBX out to the public telephone network.

P

PABX / PBX Private (Automated) Branch Exchange
The multiple-handset telephone equipment (usually) installed at your premises.
PDR Product Defect Report
The in-house term for user support requests. Users can submit one via the Help & support page.
POTS Plain Old Telephone Service
The traditional, wired, world-wide telephone system.
PSTN Public Switched Telephone Network
The traditional, wired, world-wide telephone system.

Q

QoS Quality of Service
The overall quality of the telephone service — clarity of the call, delays in speech and other errors.

R

Ring out
A call was not answered for so long the PBX or telephone company gave up and terminated it.
Ring time
The duration the telephone rang before being answered.

S

SMDR Station Management Detail Recording
Information that a PBX makes available to a connected device (typically a computer), describing each call as it happens — including time and duration.
Station
A station is the telephone extension — for example extension 100 or 101.
STD Subscriber Trunk Dialing
Also known as subscriber toll dialling — a telephone system allowing subscribers to dial trunk calls without operator assistance.
Station group
A hunt group used during a particular period — for example, during a marketing campaign.

T

Tandem call
A call between two outside lines. The two outside lines may have been joined by a user on an extension who later drops out of the call — or an inbound call may have been forwarded to another outside line.
Trunk
A telephone line provided by your telephone company. A residential address typically has a single line; an office typically has more than one.
Trunk group
A number of similar trunks — for example lines from a single telephone company, or trunks with the same cost.
Two-step authentication (2FA)
Requires two different types of authentication: (1) what you are (fingerprint, iris scan), (2) what you know (password, secret phrase) or (3) what you carry (ID or swipe card).
Two-step verification
Uses the same type of identification from two different providers — for example, a password plus a one-time code from a security token or authenticator app.
TXT, .txt
A text file with records separated, or delimited, by tabs. A very simple file format readable on virtually any computer.

U

UTC Universal Time, Coordinated
Shares the same time as GMT (Greenwich Mean Time). World times are offset from this standard.

V

VoIP Voice over Internet Protocol
A means of using the internet to make telephone calls. Depending on the installation and service, there may be very little to distinguish a VoIP call from a PSTN call — including quality of service and the physical appearance of handsets.

X

XML, .xml eXtensible Markup Language
A general-purpose specification used to create custom definitions describing how data is structured. Widely used to share information between computers over the internet, regardless of operating system.

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