Telecom Glossary of VoIP

Agent

A staff member who works from within the telephone support service of a company.

Alcatel

A French company that, among other products, manufactures VoIP telephones.

Analog

Commonly used term for analog signal transmission. Analog telephony has been largely replaced by digital ISDN. However, in many countries, analog telephone lines are still in use.

Analog Telephone Adapter (ATA)

A device that is used to incorporate analog devices into a VoIP environment by converting analog signals into IP packets.

Appliance

A common term for the hardware that is hosting the telephony software and in combination provides a telephony server.

The former term for the AskoziaPBX hardware systems that are now called telephony servers.

Applications

Asterisk applications provide the possibility to place certain program sequences for certain scenarios on specific internal or external phone numbers. An application is started by calling its respective number.

Area Code

A numeric string that defines a specific region or country as part of a telephone number. Area codes include country codes, cities or even municipalities.

AskoziaPBX

The flagship product of Askozia and the most intuitive software PBX in the world.

Asterisk

A free computer software that offers a wide range of functions of telephone systems. More about Asterisk.

Automatic Call Distribution (ACD)

To ensure the best possible handling of incoming calls, an ACD system automatically takes and distributes calls to certain employees within a company.

Particularly, call groups can be specified and assigned to the digits of the telephone keypad. An incoming call then automatically gets routed depending on the digit pressed by the caller.

Bandwidth

A defined signal processing measure that is used to describe transmission power. For IP telephony, approximately 100 Kbits per second are required respectively for upload and download for each established conversation.

Basic Rate Interface (BRI)

A base terminal of the ISDN technology.

Busy

SIP status can be sent when a telephone is called that is already involved in another conversation.

Busy Lamp Fields (BLF)

Show the status (busy, ringing, available) of the phones of other users that are connected to your phone system.

Often exists in combination with speed dial keys.

Beronet

Manufacturer of telephony hardware from Berlin, Germany.

Call

Attempt to establish a telephone conversation.

Call Center

Company or department that is responsible for handling incoming calls. Usually found in departments with high call volume.

Outbound Call Centers perform calls to the outside world, usually calling clients and potential clients.

Call Detail Records

List of calls that have been conducted through a telephone or a PBX.

Call Flow

Graphical call schedule that allows to processing of incoming calls automatically. Call Flows allow easy implementation of complex telephony scenarios.

Call Flow Editor

A graphical editor that allows the display of complex call flows as diagrams easily by drag and drop. Learn more about Askozia’s Call Flow Editor

Call Group

Logical linking of several telephony devices into groups, allowing phones within the same call group to be reached through the same phone number and ring simultaneously.

Callee

Receiver of a phone call

Caller

The person who initiates a phone call.

Caller ID

Used to identify phones. Usually sent as a combination of name and number of the caller. It is shown on the display of the callee’s phone.

Computer Telephony Integration (CTI)

Software that enables connection of VoIP phones and computers, allowing to control of the functions of a telephone from a computer.

Conference Call

Merges several communication channels to allow multiple participants to join a meeting and communicate with each other at the same time.

Connection

In terms of telephony, connection usually refers to an established conversation channel for sending audio and video signals.

Dial Pattern

A combination of digits assigned to a specific decision, such as which provider to choose or whether a call is addressed internally or externally.

Dial Plan

Specifies how to interpret dialed numbers, for example as internal extensions, local numbers, long distance, or international numbers.

Digital Enhanced Cordless Telecommunications (DECT)

An international standard for wireless telecommunication, especially for cordless phones. Learn more about DECT.

Do Not Disturb (DND)

Telephone function that has all incoming calls rejected and not signaled on the device.

Dual Tone Multi-Frequency (DTMF)

Transmission method for telephone numbers that is used to transmit numbers through the telephone keypad. For IP telephony, SIP messages are sent instead of tones.

Echo Cancellation

An algorithm that can be implemented both in hardware and software and ensures that echoes are suppressed during audio transmission through a telephone line.

External Call

General term for both incoming and outgoing calls with dialogue partners from outside of the own network.

Facsimile (FAX)

Analog transmission of documents as images through the telephone networks.
Foreign Exchange Office (FXO): An analog interface to connect with telephone systems or providers.

Foreign Exchange Station (FXS)

An analog interface to connect with devices such as telephones or faxes.

Forwarding Allows to redirect calls from one phone to another one, without the need to answer the call first.

Gateway

An electronic device that can connect different network technologies.

Gigaset

Manufacturer of DECT and VoIP phones from Düsseldorf, Germany

Handset

Part of a telephone that contains both microphones and earphones.

Headset

A combination of headphones and microphone can be connected to a phone or to a computer to communicate through a softphone.

Hold

If a dialogue partner is set on hold, the audio connection gets interrupted. The waiting dialogue partner can listen to hold music until being transferred or retrieved back into the conversation.

Hunt Group

Logical linking of several telephony devices.

If a hunt group is called, all telephones belonging to that group ring one after the other in a pre-defined order until the call is answered or the caller hangs up.

Incoming Call

External calls are received from the outside world on a PBX or telephone.

Integrated Services for Digital Network (ISDN)

Telecommunication standards were established to replace the analog telephone network in the mid-90s, integrating both speech and data on the same communication lines.

Inter-Asterisk-Exchange (IAX)

A protocol used by Asterisk telephone systems to connect between multiple Asterisk servers or between an Asterisk server and a device.

Interactive Voice Response (IVR)

Enables a computer to interact with humans by using voice recognition and DTMF tones input via a phone keypad, enabling automated interaction e.g. between customers and a company’s telephone system and thus simplifying call management and forwarding.

Internal Call

A call between two users who are logged on to the same phone system, and thus does not require building up an external connection.

Internet Protocol (IP)

The principal communication protocol for delivering data packages through the internet from the source to the destination is based on IP addresses.

IP Address

A numerical label assigned to each device connected to a network that uses the Internet Protocol for communication.

Allows to identify and locate devices within a telecommunications network to enable data transfer.

Jitter

A variation in the transmission of digital signals

Lightweight Directory Access Protocol (LDAP)

An LDAP server typically provides a central address or phone book to the network that can be accessed by clients such as IP telephones at the same time.

Line

The term telephone line remains from the past, where a two-wire cable was required for each phone conversation.

Log

Collects system messages that provide information to the user on certain events or errors in the telephone system.

MAC address

Hardware address for network-enabled devices that is set by the manufacturer of the device and cannot be changed.

Thus, enabling globally distinct identification of the device.

Mailbox

Also Voice Mailbox or Inbox. A Software that automatically takes calls and provides the opportunity to the caller to leave a voicemail for the callee.

Music-on-Hold

An audio file is played to callers if they have to wait in a call queue or are set on hold.

Night Switch

A function that allows to activate absent messages automatically, such as outside office hours or on weekends and holidays.

Network

Integration of multiple computers or other IP devices that share common services and resources and can therefore communicate with each other.

Notifications

Often used as a general term for different types of system messages such as missed calls or incoming voicemails.

Offline

Frequent synonym for being disconnected and consequently unreachable

Online

Frequent synonym for being connected and consequently reachable

Outgoing Call

A call that leaves the internal network and leads to the outside world, becoming an external call.

Private Branch Exchange (PBX)

Private telephony systems are typically for businesses connecting internal phones with each other, as well as enabling external connections through VoIP, ISDN, or analog providers.

Pickup Group

Logical linking of several telephony devices into a pickup group allows to pick up calls from other phones of this group.

Polycom

US American manufacturer of VoIP phones and other devices.

Port

The Hardware connection of a device.

Power over Ethernet (PoE)

Indicates devices that are powered through the network cable or can supply other devices themselves.

Primary Rate Interface (PRI)

ISDN connection type that allows up to 30 telephone channels.

Protocol

A protocol or data protocol that regulates the time scheduling of data transfer, as well as the conditions for communicating through the respective protocol.

Provider

Businesses that offer services allow (among others) phone calls or internet connections.

Provisioning

Configuration of an IP phone through the IP telephony server, or PBX. Automated provisioning does not require manual configurations on the phone.

Public Switched Telephony Network (PSTN)

Usually refers to analog and ISDN transmissions.

Quality of Service (QoS)

Measure to ensure the quality of internet service providers by comparing the user requirements and the potential capacity of the service provider.

Queue

A call queue puts incoming calls in line until someone is available and typically plays on-hold music to the callers in the meantime.

Several agents can be assigned and logged into a queue in order to answer the calls together.

Real-Time Transport Protocol (RTP)

Data protocol for transmission of audio and video data in IP-based networks.

Request for Command (RFC)

RFC documents are official documents of Internet specifications, communications protocols, procedures, and events, published by the Internet Engineering Task Force (IETF) and the Internet Society.

Secure Shell (SSH)

Network protocol is used to enable encrypted and secure connections to a remote network device and this way, for example, to access the console of the device.

Session Initiation Protocol (SIP)

A network protocol for establishing and controlling connections within an IP network.

SIP allows the establishment of telephony channels that can be used for transmitting instant messages, and audio and video data using RTP.

Snom

Manufacturer of VoIP phones and other devices, located in Berlin, Germany

Softphone

Software that provides telephony functions on a PC as an alternative to SIP-based desk phones.

Speed Dial

Phone numbers or commands can be placed on the speed dial keys of the telephone, allowing one to call them by pressing a single key.

Telephone

Communication devices, transmit sounds, languages, and video. Available for different transmission techniques such as SIP, ISDN, and analog.

Telephone Connection

This is a technical infrastructure that is provided by a network operator to connect to the public switched telephone network (PSTN) and establish phone calls.

Telephony Server

Alternative term for PBX, and referring to the AskoziaPBX hardware systems (formerly also called appliances).

Text-to-speech (TTS)

Texts are transformed into computer-generated synthesized speech, for example as part of an IVR system.

Tiptel

Manufacturer of VoIP phones and other devices, located in Ratingen, Germany

Transfer

PBX function that allows to forwarding of active calls to another callee.

There are two types of transfers, blind (without notice) and attended (with notice). For blind transfers, the call is passed to the new callee without preliminary notification.

Contrary, for attended transfer, the transferring party and the new callee first have a brief consultation whereas the caller is put on hold and hears music.

Video Phone

A telephone with a video display that allows simultaneous video and audio transmission in real time.

Video Codecs

Algorithms that compress and encode, or decompress and decode digital video. Once a video gets compressed to reduce its size and increase data transfer speed, it permanently loses some of its information, that is to say, quality, dependent on the chosen video codec.

Video Telephony

The transmission of video data in parallel to speech during a telephone conversation using a videophone.

Voicemail

Voice message by a caller that is recorded by the mailbox and can be listened to later by the callee.

Virtual Private Network (VPN)

Connection between two network devices, that is secured through certification. Data transfer is encrypted to protect the transmitted data.

Yealink

Chinese manufacturer of VoIP telephones and other devices.

Zoiper

Softphone supporting SIP and IAX.