The Complete Alphabet of Telephone Terms

Whether you’re new to the industry or a telephony veteran, the vocabulary in the telephone industry can get a bit confusing. New words are constantly being added as technology changes. This comprehensive list of common telephony terms will help you feel more comfortable in conversations and sound like a telephony pro!


AA (Auto Attendant) – Also called a virtual receptionist, an auto attendant is an audible menu system allowing callers to be transferred to an extension or ring group without going through a live receptionist. Some companies use auto attendants for high call volume or as a backup plan when the main operator is out of the office.

ACD (Automatic Call Distributor) – A way to distribute phone calls to a group of people in a logical manner. An ACD often uses a voice menu to manage incoming calls based on the number called and an associated database of handling instructions.

Analog – Analog systems have supported businesses for decades, though they are now becoming outdated. Analog systems are built on standard copper wire and POTS (plain old telephone service) phones and have the basic features you might find in a typical home phone such as hold, mute, redial, and speed dial. This is your basic phone system with the cord and handset.

Attended Transfer – A type of transfer in which you announce to callers the person or department you are transferring them to. Also known as warm transfer.

Barging – Barging allows a third party (typically a manager or supervisor) to join a conversation on the phone system; both parties on the line can hear the third party. Barging is typically used in call centers.

Blind Transfer – A type of transfer in which you do not notify the receiving party of the incoming call. Also called unattended transfer or cold transfer.

Button Module – A module you can add to the side of a phone that gives you additional programmable buttons. The button module is commonly used by receptionists, telephone attendants, and assistants to create speed dials for transferring.

Call Monitoring – Call monitoring is the process of listening to current or previously recorded calls to assess the performance of call representatives, boost sales campaigns, or identify training needs.

Call Parking – Call parking can be best described as a virtual hold. Newer phone systems have separated the hold feature and park feature. The hold feature is used for one phone, meaning the physical phone at your desk. Call parking enables employees to send the “hold” from one phone to another anywhere within the office phone system. Unanswered calls can be programmed to ring back, ensuring your customers are not waiting for extended periods of time.

Caller ID – A telephone service that transmits the phone number when placing a call. The information will be visible on the called party’s telephone if the equipment supports displaying caller ID. The display may also include the caller's name, known as CNAM.

Carrier (or Telecommunications Service Provider) – Carriers are the companies that provide the actual phone service behind the scenes. For example, some of today’s popular carriers are AT&T, Spectrum, and Verizon.

Click to Dial – A type of digital communication, commonly a Google extension or web extension, that allows users to click on a phone number on the computer and instigate automatic dialing of that number. Some CRMs (customer relationship management) platforms use this feature.

Cloud Phone Systems – A cloud phone system is hosted in the cloud, meaning that data is stored in a secure server that you can reach over the internet. You may see cloud phone systems called hosted phone systems or hosted PBX.

CNAM (Caller ID Name) – CNAM is the transmission of a caller ID name. It is typically paired with the transmission of a caller-identification phone number. CNAM helps recipients of a call easily identify the caller.

Codec – A codec encodes your voice into a digital signal and then decodes it back into analog sound for another person to receive.

Dial-by-Name Directory – The dial-by-name directory is a possible feature of an Interactive Voice Response (IVR). Using the directory allows a caller to search for someone in a phone system without talking to a human, saving time in the workday and the cost of a receptionist position.

Dial Tone – The sound you hear when an off-hook condition is detected on the telephone. The dial tone indicates the phone is connected and ready to initiate a telephone call.

Directory – All the extensions and/or phone numbers on a phone system for a caller to choose from.

DTMF Tone – The sounds used for touch-tone dialing are referred to as DTMF (Dual-Tone Multifrequency) tones. Each number (as well as the "#" and "*") is associated with two combined tones that form a single sound. This is the tone your phone makes when you push numbers to dial.

E911 – E911 sends your address information along with your phone number to the dispatchers when you dial 911.

Extension – A telephone extension may refer to a phone on an internal telephone line attached to a private branch-exchange (PBX) system. It allows multiple lines inside the office to connect without each phone requiring a separate outside line.

ForwardingCall forwarding is the act of transferring all calls from a desk phone to a cell phone, whether through an app or directly. There are many options with forwarding. You could forward right away or wait and forward after a specified number of rings. Situational forwarding is an option as well within the office.

Hot Desking – Typically used with businesses with extended hours or twenty-four-hour service, hot desking allows multiple people to log into the same physical phone but with their own log-in as they switch shifts. This saves on the cost of multiple phones but keeps productivity optimal.

ISP (Internet Service Provider) – An ISP is a company that provides individuals and companies with access to the internet and other related services such as website building and virtual hosting. Some examples of ISPs are AT&T and Spectrum.

ITSP (Internet Telephony Service Provider) – An ITSP offers digital telecommunications services based on Voice over Internet Protocol (VoIP) and is maintained through the internet. ITSPs provide services to end users directly or as wholesale suppliers to other ITSPs.

IVR (Interactive Voice Response) – IVR allows a computer to interact with humans using voice and DTMF tones through a keypad. It is often used in conjunction with an auto attendant.

Legacy – This is an older phone system that uses traditional phone lines (connected to the phone company) and are not IP-based. The hardware is typically located in the building, taking up much-needed space; legacy phones are going out of style, and the majority of businesses have switched to VoIP.

Message on Hold – Message on Hold (MOH) is a service that helps businesses deliver customized messages to callers and customers whenever they are placed on hold. This is often spoken word as opposed to music.

Multibranch Integration – This is when you take a company with multiple locations and put them on the same phone system or network if it is for a data provider. This simplifies the calling process and helps clients reach the proper people no matter what.

Music on Hold – This is the tune that plays for a caller when they are on hold or park.

On-Premises – Hardware and software are on the premises of the company rather than being virtual. On-premises phone systems are usually found in the data closet.

Paging – Paging is the act of notifying someone that he or she is needed, typically via a public-address system or over the speakers of the office telephones. Overhead paging systems can be integrated with phone systems when additional volume is needed.

PBX (Private Branch Exchange) – PBX is a term people use for a business telephone system that switches calls between users on local lines while allowing all users to share a certain number of external phone lines. The purpose of a PBX is to save the cost of needing a line for each user to the telephone company's central office.

Porting – The process of moving your phone number from one carrier to another.

POTS (Plain Old Telephone Service) – This is the phone service commonly associated with analog phones. It is a basic service that is commonly steered clear of today.

Presence – The visual representation of someone’s status on the phone system. This feature displays whether an employee is on the phone, free, or busy.

PRI (Primary Rate Interface) – A PRI circuit is a single fiber-optic cable in the building that allows you to have twenty-three simultaneous phone calls.

Queue – A queue on a phone system is just like standing in line at a grocery store. A queue is a virtual space where callers can wait in line for someone to reach their call. Queues can be routed based on number in line, skills of certain responders, language, etc.

Ring Back Tone – Tone heard by a caller before anyone on the receiving line has answered the phone.

Ring Group (Hunt Group) – A feature that allows you to have multiple phones ring when one number or extension is dialed. A ring group is a way for a business to share the delivery of incoming calls between employees. It is commonly used to distribute calls to specific departments, such as sales or support.

Round Robin – A type of ring group that allows you to distribute calls evenly among a specific group of people. Instead of ringing all employees of the group at the same time or randomly, the system takes turns calling people in a specified order, such as Allen > Susan > Jessica.

Sidecar – A module you can add to the side of a phone that gives you additional programmable buttons. A sidecar is commonly used by receptionists, telephone attendants, and assistants to create speed dials for transferring.

SIP (Session Initiation Protocol) – A protocol used in VoIP communications that allows users to make voice and video calls, mostly for free. SIP allows people around the world to communicate using computers and mobile devices via the internet.

SIP Trunk – Type of VoIP that enables the end point’s PBX to send and receive calls using the internet. Think of it like a virtual version of an analog phone line. If a business has an on-premises PBX in its office, a SIP trunk can connect and allow employees to make outbound calls on the existing system, without restrictions on the number of concurrent calls.

Situation Call Forwarding – A type of call forwarding that filters certain calls to be forwarded based on specific requirements such as time, incoming caller ID, and more.

Soft Phone – Any non-telephone device containing a soft-phone application that allows you to make telephone calls over that device. The user can send and receive calls and messages from a mobile device, tablet, or desktop computer as if it were a traditional phone.

T-Carrier – A T-carrier is a digital communication service used for wide-area networks (WANs), company remote access, high-speed internet access within a business network, and more. T-carriers use two pairs of wires, one pair for sending and one for receiving.

Three-Way Calling – Three-way calling allows you to have three people on a call together at one time. All parties can hear and speak to one another. Most phone systems and cell-phone plans have three-way calling included.

Toll-Free – A toll-free telephone number is a number that is billed for all arriving calls instead of sending charges to the calling party. These phone numbers are common with businesses. In the United States, toll-free numbers have one of the following area codes: 800, 833, 844, 855, 866, 877, or 888.

Transfer – Sending a phone call from one extension to another extension based on the needs of either party on the line. Transfer types include blind transfers and attended transfers.

Twinning – A feature on a phone system that can be set up so that the user’s office phone and cell phone ring at the same time. Some phone systems allow you to move from cell phone to office phone and back without disconnecting the call.

Visual Voicemail – A feature that adds a visual interface to standard voicemail capabilities. You no longer need to dial in and listen to prompts to check your voicemail. Think of the voicemail options on your smart phone where you can click on a message to hear it.

Voicemail – Voicemail is a basic feature on most business phone systems that allows your callers to leave voice messages. Voicemail is also referred to as an “answering machine” or “voice bank.”

Voicemail to Email – This feature sends messages to your email when you receive a voicemail. It can simply alert you when you have a voicemail, send you the recording as an audio attachment, and/or convert the audio to text.

Voicemail Transfer – The act of transferring an incoming call directly into voicemail by passing the ring function. Secretaries often use this feature if they know an employee is out of the office or busy.

Voice to Text – A feature used in voicemail that converts voice recordings to a typed-out version that the receiving party can read instead of listen to. It is typically paired with the voicemail-to-email feature.

Whispering – Whispering is a feature common to call centers. A manager can hear a two-way phone conversation and talk to you while you’re on the phone, but a customer on the other side of the line can’t hear it. This is often used for training purposes for sales or support roles.

Of course, the most important lesson for a non-telephony pro is how to pronounce "telephony."

Now that you know the major telephony terms, you are well equipped to take on the world of telecommunications and sound like an expert! If you are looking to improve your business, contact TelWare at 1-800-637-3148 or sales@telware.com to request a demo!

TelWare is a national leader in the installation of voice, video, and data solutions.

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