Analog
Comes from the word "analogous," which means "similar to." In telephone transmission, the signal being transmitted is "analogous" to the original. In correct English usage, "analog" is meaningless as a word by itself. But in telecommunications, analog means telephone transmission and/or switching which is not digital.

Audio Text
A pre-recorded message heard by system users.

Automated Attendant
A specialized form of an Interactive Voice Response system. An IVR connected to a PBX. When a call comes in, this device answers it, and says something like: "Thanks for calling the ABC company. If you know the extension number you'd like, push button that extension now and you'll be transferred. If you don't know it, push-button "0" (zero) and the live operator will come on. Or wait a few seconds and the call operator will come on anyway." Sometimes the automated attendant might give you other options -- like "dial 3" for a directory. Automated attendants are sometimes connected also to voice mail systems ("I'm not here. Leave a message for me."). Some people react well to automated attendants. Others don't. A good rule: Before you spring an automated attendant on your people/customers/subscribers, etc., let them know. Train them a little. They'll then perceive the automated attendant device a lot more positively. Tip: When you reach an automated attendant and don't know the extension number, dial the person's last name on your Touch Tone pad. Better automated attendants will recognize the name and translate it into the extension number.

Automatic Speech Recognition (ASR)
Describes a group of special technologies that allow callers to speak words, phrases, or utterances that are used to control applications. In the case of voice processing, speech recognition is used to replace touch-tone input, make for more intuitive menu structures, and add a level of simplicity and security to some systems. Speech recognition is often confused with voice recording or voice digitization. Voice digitization and recording explain how the human voice is captured, digitized, and stored for later play back. Speech recognition, on the other hand, is a technology that uses the spoken word as input that has an effect on the logic flow and execution of the program in question.

Call Accounting
An information system that records and reports on telephone calls. Call accounting is used by most large companies to control expenses and allocate costs to various departments as well as by hotels, hospitals and other organizations that resell calls to its clientele.

Call Blocking / Do Not Disturb
This gives a system subscriber the option to block all calls to his or her telephone extension. Callers automatically receive the personalized greeting and are given the option to leave a message.

Call Center
Any location within a company where quantities of incoming and/or outgoing calls are handled by people, telephones, and computers. Call centers route calls to the appropriate agent or operator.

Call Processing
The system and process that sets up the intended connection in a switching system. The system scans the trunk and/or station ports for any "requests" for service.Upon detecting a request, the system checks the stored instructions and look-up tables and sets the connection up accordingly.

Call Queing
When an extension is busy, the callers are given the option to hold, leave a message, or try another extension. Note the term "Queuing" is also used to describe multiple calls holding for the same extensions.

Call Screening
This allows subscribers to answer their extensions, be told who is on the line (callers are asked by the system to speak their name before their call is connected), and choose to accept or reject the call.

Centrex
A generic term for telephone company-based PBX-like service. Centrex service is a partition of a local Central Office switch that emulates the functions of an on premises switch. In some cases, the Centrex service is provisioned from a switch located on the subscriber's premises. In all cases, the subscriber pays a fee for the use of the Centrex service, but never owns the switch or maintains his or herself. Centrex lines are run from the Central office to each users' phone. Features such as transfer, conference, speed dial, etc. are provided by Centrex as they are on PBXs.

Computer Telephony
A broad term encompassing all aspects of applying computer-based intelligence to the making and receiving of phone calls. This takes in many disciplines including voice store & forward, computer-based fax, Internet Telephony, Call Centers, CTI (Computer Telephone Integration, voice messaging, voice recognition, text-to-speech, call control, IVR (Interactive Voice Response), Web-enabled call-back, and call control. Computer Telephony also includes the API's Apps Gens and other software used to glue disparate systems together in order to achieve more intelligent handling of phone calls.

Computer Telephone Interface (CTI)
Combining data with voice systems in order to enhance telephone services. For example, automatic number identification allows a caller's records to be retrieved from the database while the call is routed to the appropriate party. Automatic telephone dialing from an address list is an outbound example.

Direct Inward Dialing (DID)
The ability for a caller outside a company to call an internal extension without having to pass through an operator or attendant. In large PBX systems, the dialed digits are passed down the line from the CO (central office). The PBX then completes the call. Direct Inward Dialing is often proposed as Centrex's major feature. But automated attendants (a specialized form of interactive voice response systems) also provide a similar service.

Distribution List
A Distribution List contains the Mailbox Numbers of the subscribers included in the Distribution List.

Dual Tone Multi Frequency (DTMF)
A fancy term for describing push button or Touch Tone dialing. (Touch Tone is a registered trademark of AT&T.) In DTMF, when you touch a button on a push-button dial, it makes a tone, which is actually the combination of two tones, one high frequency and one low frequency. Thus the name Dual Tone Multi Frequency. In U.S. telephony, there are actually two types of DTMF signaling -- one that is used on normal business or home push-button/Touch Tone phones, and one that is used for signaling [T103] within [T101] the telephone network itself. When you go into a central office, look for the test-board. There you will see what looks like a standard Touch Tone pad.Next to the pad there will be a small toggle switch that allows you to choose the sounds the Touch Tone pad will make -- either normal Touch Tone dialing or the network version.

Fax Back / Fax On Demand
Fax back service allows callers to use touch-tones or voice commands to select and later receive fax documents. There are two types of fax-back: 1) One-call requires the user to pay for the call to the fax-back machine. Typically, the caller initiates the transaction from his or her fax machine. An audio menu prompts the caller to enter a document number after which he or she touches the "start" button on the fax machine and puts the handset back in its cradle. The fax is then transmitted "on the caller's dime;" 2) Two-call-fax-back allows callers to initiate the transaction by typing in the destination fax machine number from any phone. A second call is then made by the fax-back machine to deliver the fax to the designated fax number.

Inband Signaling
Signaling made up of tones which pass within the voice frequency band, and are carried along the same circuit as the talk path that is being established by the signals. Virtually all signaling -- request for service, dialing, disconnect, etc. --in the U.S. today is in-band signaling. Most of that signaling is MF -- multi-frequency dialing. The more modern form of signaling is out-of-band.

Information Center Mailboxes
A voice bulletin board on a voice mail system. Here's their explanation: Multiple callers can access, directly or indirectly, recorded announcements containing information that would otherwise have been given live by employees. Callers are frequently "outside" users of the system.One type of "listen only" mailbox simply plays the message to the callers. This technology, sometimes known as audiotex, makes it possible to create a verbal database so callers can select which information they want to hear. Another type of Information Center Mailbox prompts callers to reply to announcements. Callers wanting further information can be given the opportunity to leave their names and phone numbers after listening to a product description. They can also be transferred to a designated employee who can immediately take an order. If desired, a password can be required before confidential or controlled access information can be heard.

Interactive Voice Response (IVR)
A voice processing system that interfaces with a database to provide callers with specific information. Callers input their unique identifying data—either by pressing certain digits on the touchtone telephone or via speech recognition—and the system responds with the requested information. Banking by telephone is an example of an IVR application.

Loop Start
You "start" (seize) a phone line or trunk by giving it a supervisory signal. That signal is typically taking your phone off hook. There are two ways you can do that -- ground start or loop start. With loop start, you seize a line by bridging through a resistance the tip and ring (both wires) of your telephone line.

Port
A point of access to a telephone system, a computer, or a network.

Prompts
Prerecorded messages or instructions within a voice messaging system that are designed to guide the caller through the system, e.g., "If you know your party's extension, you may enter it at any time during this message."

Simplified Message Desk Interface (SMDI)
A data link used to communicate between the switch an the computer telephony system to carry call progress and call control information. SMDI was developed to allow central office-based switching services to integrate with customer premises equipment. You can get SMDI as an Essex, Centrex, Centron, etc. service. The SMDI protocol specifies the extension number tried for and the condition of the called extension.

T1
A digital transmission link with a capacity of 1.544 Mbps (1,544,000 bits per second). T1 uses two pairs of normal twisted wires, the same you use in your house. T1 normally can handle 24 voice conversations with each conversation being digitized at 64 Kbps. But, with more advanced digital voice encoding techniques, it can handle more voice channels.

Telephony Application Programming Interface (TAPI)
A set of guidelines developed by Microsoft and Intel Corporation for connecting individual PCs directly to telephones. TAPI is designed for small business networks.

Text to Speech (T2S / TTS)
Text-to-speech technology allows an alternate spoken method for conveying textual information. As the name implies, text-to-speech converts ASCII text into the spoken word. Instead of a digitized recording, however, a synthesized voice is used in order to speak-out words and phrases on-the-fly. Applications for this technology include order entry systems (providing verbal confirmation on hundreds of products), customer name and address systems (access to thousands of addresses and names for locator capabilities), and telephone access to e-mail messages. In addition, TTS can be used to gain access to news information for stock quotes so brokerage firms can give callers access to corporate news headlines along with stock quotes. Newspaper access for the blind is another use for TTS technology.

Unified Messaging
A communications solution that unifies a single message store and directory with a desktop client application, providing users with one central point of access to all their voice, fax, and e-mail messages. Messages are delivered to a single inbox, housed in one central message store, and feature single directory service. This means that users have global addressing capability, and can use a single directory to address all their messages, regardless of media. Unified messaging solutions are also designed to work with open standards while fitting snugly into proprietary groupware environments. This means that system administrators have one central point of access for all support and maintenance tasks.

Voice Mail
An application of store and forward wherein telephone access to private messages are retrieved by the users for playback. Imagine a shared tenant answering machine that handles multiple telephone lines and can record messages for hundreds of people simultaneously. Imagine the intended parties being able to retrieve these messages over the phone with simple touch tone commands. Imagine full security, so that no one can pick up anyone else's message with a special, private access code. That's voice messaging. Some systems support broadcast of messages to multiple recipients, message waiting notification via pager, message waiting light, email or "outdial" telephone calls.

Voice over Internet Protocol (VoIP)
The two-way transmission of audio over a packet-switched IP network (TCP/IP network). When used in a private intranet or WAN, it is generally known as 'voice over IP,' or 'VoIP.' When the transport is the public Internet or the Internet backbone from a major carrier, it is generally called 'Internet telephony.' However, the terms IP telephony, Internet telephony and VoIP are often used interchangeably.