Numerics

Digital information carried by two B-channels for better performance and quality; the bit rate is twice that of one B-channel used alone.

A family of digital multiline and digital single-line telephones.

A

Code used to associate incoming and outgoing calls with corresponding accounts, employees, projects, and clients.

AT&T's switched digital service for 56-kbps, 64-kbps restricted, and 64-kbps clear circuit-switched data calls.

Coded representation of the destination of data or of the data's originating terminal, such as the dialed extension number assigned to the data terminal. Multiple terminals on one communications line each must have a unique address.

Automated Document Delivery System. Computer-based application that stores documents in a database and automatically faxes them on request.

Optional equipment used with the communications system, such as an alerting device or modem that connects to a multiline telephone or to an extension jack.

Automatic Line Selection. Programmed order in which the system makes outside lines available to a user.

Numbering of extension ranges, remote access codes, or other system components that causes conflicts in network operations. These numbers can be unique and still be ambiguous. For example, Extension 441 is different from Extension 4410; for UDP routing purposes, however, the two numbers are ambiguous and a call intended for Extension 4410 would be misrouted, on the first three digits sent, to Extension 441. See also Unambiguous Numbering.

Alternate Mark Inversion. Line coding format in which a binary one is represented by a positive or negative pulse, a binary zero is represented by no line signal, and subsequent binary ones must alternate in polarity; otherwise, a bipolar violation occurs. AMI is used in the DS1 interface.

See Modem Data Station.

Mode of transmission in which information is represented in continuously variable physical quantities, such as amplitude, frequency, phase, or resistance. See also Digital Transmission.

Automatic Number Identification. Process of automatically identifying a caller's billing number and transmitting that number from the caller's local central office to another point on or off the public network.

Software and/or hardware that adds functional capabilities to the system. For example, MERLIN MAGIX Reporter is an application that provides call management information (if available in the local area or jurisdiction).

Automatic Route Selection. System feature that routes calls on outside facilities according to the number dialed and line/trunk availability. To initiate ARS, the user dials a dial-out code, also called an "ARS access code."

American Society of Composers, Artists, and Producers.

ISDN-BRI bridge/router that enables high-speed Internet access over a digital facility. It makes outgoing calls only.

AT&T Switched Network. AT&T telecommunications services provided through an Integrated Digital Services Network Primary Rate Interface (ISDN-PRI) trunk, ACCUNET switched digital service, MEGACOM, MEGACOM 800, Software Defined Network (SDN), Multiquest, and Shared Access for Switch Services (SASS).

Method of transmitting a short bitstream of digital data, such as printable characters represented by a 7- or 8- bit ASCII code. Each string of data bits is preceded by a start bit and followed by a stop bit, thus permitting data to be transmitted at irregular intervals. See also Synchronous Data Transmission.

Application with equipment that connects to one or more tip/ring extension jacks and automatically answers incoming calls with a recorded announcement; directs calls in response to Touch Tones.

See ASN.

An application that automatically answers incoming calls with a recorded announcement and directs callers to a department, an extension, or the system operator.

See ADDS.

Process that occurs in a private network when all available routes for a call specify systems with matching switch identifiers. The call is routed from the originating system to the destination system and back to the originating system in a continuous loop. Switch identifier labeling systems must be unique across a network.

See ALS.

See ANI.

See Automatic-Start Tie Trunk.

See ARS.

Tie trunk on which incoming calls are routed to an operator or other designated destination without a start signal, as soon as the trunk is seized; the destination is specified during programming. Also called "Automatic Ringdown" or "Auto-In" Tie Trunk.

B

Bipolar 8 Zero Substitution. Line-coding format that encodes a string of eight zeros in a unique binary sequence to detect bipolar violations.

Procedure for saving a copy of system programming onto a floppy disk or memory card. See also Restore.

Difference, expressed in hertz, between the highest and lowest frequencies in a range that determines channel capacity.

Password used to limit access to the Remote Access feature of the system. In a private network, it is especially important that barrier codes be required for all types of remote access.

Hardware that holds and connects the processor module, power supply module, and up to five other modules in the system. see ########## also see ########## Expansion Carrier.

Strictly speaking, a measurement of transmission speed equal to the number of signal level changes per second. In practice, often used synonymously with bit rate and bps.

Bearer-Channel. 64- or 56-kbps channel that carries a variety of digital information streams, such as voice at 64 kbps, data at up to 64 kbps, wideband voice encoded at 64 kbps, and voice at less than 64 kbps, alone or combined.

See BRI.

See B-Channel.

One of three modes of system operation in which the control unit is connected to (behind) another telephone switching system, such as Centrex or DEFINITY, which provides features and services to telephone users. See also Hybrid/PBX Mode and Key Mode.

Electrical representation of quantities or symbols expressed in the base-2 number system, which includes zeros and ones.

See B8ZS.

Digital signal in which pulses (ones) alternate between positive and negative. See also AMI, B8ZS, and Bipolar Violation.

Condition occurring when two positive or two negative pulses are received in succession. See also AMI and B8ZS.

Binary Digit. One unit of information in binary notation; it can have one of two values--zero or one.

Speed at which bits are transmitted, usually expressed in bps. Also called "data rate."

Condition in which end-to-end connections cannot be made on calls because of a full load on all possible services and facilities. See also Glare.

Broadcast Music Incorporated.

Module--for example, 100D or 408 MLX GS/LS--that allows you to connect lines/trunks and extensions to the communications system.

  Board Assignment

System Programming and Maintenance (SPM) procedure for assigning line/trunk and extension modules to slots on the control unit.

System programming procedure for renumbering boards that have already been assigned to specific slots on the control unit.

Bits per second.

Basic Rate Interface. Standard protocol for accessing Integrated Service Digital Network (ISDN) services.

Transmission path having a bandwidth greater than a voice-grade channel.

Multiconductor electrical path used to transfer information over a common connection from any of several sources to any of several destinations.

Key on the face of a telephone that is used to access a line, activate a feature, or enter a code on a communications system.

Sequence of eight bits processed together. Also called "octet."

C

See CAS.

See CAT.

Service provided by some local telephone companies (if local regulations allow) that supplies the calling party telephone number and name. An 800 GS/LS-ID, 408 GS/LS-ID-MLX, or 412 LS-ID-TDL module can capture both the number and name of the calling party and display them on the screens of 44xx, MLX, ETR, and MLS telephones. See also ANI.

Team of individuals who answer the same types of calls.

This central office service allows a subscriber to view the name of the calling party on a 44xx, MLX, ETR, or MLS display telephone.

This central office service allows a subscriber to view the number of the calling party on a 44xx, MLX, ETR, or MLS display telephone.

Call Accounting System. DOS- or UNIX System-based application that monitors and manages telecommunications costs.

Call Accounting Terminal. Stand-alone unit with a built-in microprocessor and data buffer that provides simple call accounting at a low cost.

International Telegraph and Telephone Consultative Committee.

Common-Channel Signaling. Signaling in which one channel of a group of channels carries signaling information for each of the remaining channels, permitting each of the remaining channels to be used to nearly full capacity. In the system's 100D module, channel 24 can be designated as the signaling channel for channels 1-23.

Programming of features on individual telephones; performed at a central location by the system manager. See System Programming and Extension Programming.

Sharing of a voice messaging system by two or more directly connected MERLIN MAGIX, MERLIN LEGEND (Release 6.1 or higher), DEFINITY ECS, DEFINITY BCS, or DEFINITY ProLogix Solutions systems in a private network.

See CO.

Set of system features to which a user can subscribe on telephone trunks from the local telephone company.

Telecommunications transmission path for voice and/or data.

See CSU.

Sum of ones in a sequence of ones and zeros, used to detect or correct errors in data transmission.

Data call made through an exclusively established and maintained connection between data stations.

See COR.

Clear data channels (also called unrestricted data channels) allow the transmission of occurrences of more than seven contiguous zero bits. If a clear data channel is requested and only restricted channels are available, the call will be rejected. See also Restricted Data Channel.

When digital signals are transmitted over a communications link, the receiving end must be synchronized with the transmitting end to receive the digital signals without errors using clock synchronization. A system synchronizes itself by extracting a timing signal from an incoming digital stream. All the digital facilities in a network operate from a single common clock--preferably a port connected to a digital PSTN facility on a hub system or a system that connects two network systems. In this case, all digital facilities specify a loop clock source. One system in a network may be specified as a local clock source when no functioning digital facility in the network is connected to the PSTN. All other digital facilities then use this clock and specify their clock sources as loop. Primary, secondary, and tertiary clock sources are specified to allow backup synchronization in the event that the primary source is out of service.

Central Office. Location of telephone switching equipment that provides local telephone service and access to toll facilities for long-distance calling.

Cable consisting of one conductor, usually a small copper tube or wire within, and insulated from, another conductor of larger diameter--usually copper tubing or copper braid.

Coder-Decoder. Device used to convert analog signals-- such as speech, music, or television--to digital form for transmission over a digital medium and back to the original analog form.

Digits that a caller dials in response to an integrated voice response application's menus; collected digits may be used to initiate a screen pop at a system extension. See also CTI Link and Enhanced Customer Care Solution.

Private network arrangement that combines characteristics of Virtual Private Network (VPN), a series configuration, and a star configuration.

See CCS.

Processor module, power supply module, other modules, carriers, and housing of the system.

Telephone and adjuncts (if any) at an operator or system programmer extension.

Entry-level voice response application that automatically answers and routes calls and executes telephone transactions.

See Modem Pool.

In a private network that includes more than two systems, the system manager who acts as a clearinghouse for any changes made on local systems that affect the network, assuring that all system managers work together and that local system changes do not have undesirable effects on the network as a whole.

Class of Restriction. Various types of restrictions that can be assigned to remote access trunks or barrier codes. These restrictions consist of calling restrictions, ARS Facility Restriction Levels (FRLs), Allowed Lists, Disallowed Lists, and Automatic Callback queuing.

Set of system features that can determine how an extension's calls are covered when the person at the extension is busy or not available.

Cyclic Redundancy Check. Error-detection code used on DS1 facilities with the extended superframe format (ESF).

Channel Service Unit. Equipment used on customer premises to provide DS1 facility terminations and signaling compatibility.

Computer Telephony Integration. Hardware/software feature that is part of the PassageWay Telephony Services application. It allows the use of Lucent Technologies-certified software applications on a LAN running Novell NetWare or Windows NT software in a Hybrid/PBX mode system. These applications may provide special features for client control of such calling activities as power dialing. See also Screen Pop.

See CRC.

D

Framing format consisting of a sequence of individual frames of 24 eight- bit slots and one signal bit (193 bits) in a 12-frame superframe. See also ESF.

See D-Channel.

See DCE.

Type of ISDN terminal adapter that acts as the DCE at a data workstation that communicates over high-speed digital facilities.

See bps.

Special type of extension where data communications take place; includes DTE and DCE; sometimes a telephone is also part of a data station.

Input/output device (often a personal computer) that can be connected to the control unit via an interface.

See DTE and Data Terminal.

Special type of extension where data communications take place; includes DTE and DCE; sometimes a telephone is also part of a data workstation.

Data Communications Equipment. Equipment, such as modems or ISDN terminal adapters, used to establish, maintain, and terminate a connection between the system and data terminal equipment (DTE)--such as printers, personal computers, host computers, or network workstations.

Digital Communications Protocol. AT&T proprietary protocol to transmit digitized voice and data over the same communications link.

Data-Channel. 16- or 64-kbps channel that carries signaling information or data on a PRI or BRI.

The imprinted feature buttons on a telephone: for example, Conf or Conference, Drop, Feature, HFAI (Hands-Free Answer on Intercom), Hold, Message, Mute or Microphone, Recall, Speakerphone or Spkrphone, and Transfer.

Tie trunk or tandem tie trunk on which the originating end of the tie trunk transmits an off-hook signal to the receiving end and waits for the receiving end to send an off-hook signal followed by an on-hook signal. Also called "dial-repeating tie trunk."

System application that allows face-to-face, simultaneous video and voice communications between individuals and requires high-speed data transmission facilities. See also Group Videoconferencing System.

Direct Facility Termination. See Personal Line.

   DHG

Data Hunt Group. Group of analog or digital data stations that share a common access code. Calls are connected in a round-robin fashion to the first available data station in the group.

See Feature Code.

See DNIS.

Digit (usually a 9) or digits dialed by telephone users to get an outside line.

Numbering scheme for system extensions, lines, and trunks.

Tie trunk on which the originating end of the tie trunk transmits an off-hook signal to the receiving end and waits for the receiving end to send an off-hook signal followed by an on-hook signal.

Direct Inward Dial. Service that transmits from the telephone company central office and routes incoming calls directly to the called extension, calling group, or outgoing line/trunk pool, bypassing the system operator.

Incoming trunk that receives dialed digits from the local exchange, allowing the system to connect directly to an extension without assistance from the system operator.

Representation of information in discrete elements--such as off and on or zero and one. See also Analog Transmission.

See DCP.

See ISDN Terminal Adapter Data Station.

See DS0.

See DS1.

See DSL.

Mode of transmission in which the information to be transmitted is first converted to digital form and then transmitted as a serial stream of pulses. See also Analog Transmission.

Dual In-line Package. Switch on a 400EM module used to select the signaling format for tie-line transmission. Also used on other equipment for setting hardware options.

DFT. See Personal Line.

See DID.

See DLC.

See DSS.

Buttons on a 4412D+, 4424D+, 4424LD+, or MLX display telephone used to access the telephone's display.

Direct-Line Console. Telephone used by a system operator to answer outside calls (not directed to an individual or a group) and inside calls, to transfer calls, to make outside calls for users with outward calling restrictions, to set up conference calls, and to monitor system operation.

Dialed Number Identification Service. Service provided by AT&T and MCI to route incoming 800 or 900 calls according to customer-selected parameters, such as area code, state, or time of call.

   Door Answering Unit

Device connected to a tip/ring jack and used at an unattended extension or front desk.

Disk Operating System.

Device that can be installed between systems connected by tandem PRI trunks or T1-Emulated tandem tie trunks to allow fractional use of the facility--that is, use of fewer than 23 of the PRI B-channels or fewer than 24 of the T1 channels. In a PRI facility, the equipment must never drop Channel 24, the D-channel. All channels must still be programmed and all count towards the system maximum of 80 lines.

Digital Signal 0. Single 64-kbps voice or data channel.

Digital Signal 1. Bit -oriented signaling interface that multiplexes twenty-four 64-kbps channels into a single 1.544-mbps stream.

Digital Subscriber Line. Digital Subscriber Line provides full-duplex service on a single twisted metallic pair (2-wire) at a rate sufficient to support ISDN Basic Rate Access.

Direct Station Selector. Fifty-button adjunct that enhances the call-handling capabilities of a 4424D+, 4424LD+, MLX-20L, or MLX-28D telephone used as an operator console.

Data Terminal Equipment. Equipment that makes the endpoints in a connection over a data connection--for example, a data terminal, personal computer, host computer, or printer.

Dual-Tone Multifrequency Signaling. Touch-tone signaling from telephones using the voice transmission path. DTMF signaling provides 12 distinct signals, each representing a dialed digit or character, and each composed of two voiceband frequencies.

E

Trunk supervisory signaling, used between two communications systems, in which signaling information is transferred through two-state voltage conditions (on the Ear and Mouth leads) for analog applications and through two bits for digital applications. See also Tie Trunk.

Electronic Industries Association.

Physical interface, specified by the EIA, that transmits and receives asynchronous data at speeds of up to 19.2-kbps over cable distances of 50 feet (15 meters).

See ESS.

Final destination in the path of an electrical or telecommunications signal.

Application that sends calls to available agents in a calling group. The Enhanced Customer Care Solution places calls in queue, plays announcements, tracks agent activity and availability, and provides real-time reports.

Extended Superframe Format. PRI framing format consisting of individual frames of 24 eight-bit slots and one signal bit (193 bits) in a 24-frame extended superframe.

Electronic Switching System. Class of central office (CO) switching systems developed by Lucent Technologies in which the control functions are performed principally by electronic data processors operating under the direction of a stored program.

Enhanced tip/ring telephone (Series 4).

Carrier added to the control unit when the basic carrier cannot house all of the required modules. Houses a power supply module and up to six additional modules.

See ESF.

Endpoint on the internal side of the communications system. An extension can be a telephone with or without an adjunct. Also called "station." See also Data Workstation.

An analog, digital, or tip/ring physical interface on a module in the control unit for connecting a telephone or other device to the system. Also called "station jack."

Programming performed at an extension to customize telephones for personal needs; users can program features on buttons, set the telephone ringing pattern, and so on. See also Centralized Telephone Programming and System Programming.

F

Equipment (often a line/trunk) constituting a telecommunications path between the system and the telephone company central office (CO).

See FRL.

Default state of a device or feature when an optional setting is not programmed by the user or system manager.

Facsimile. Scanning and transmission of a graphic image over a telecommunications facility, or the resulting reproduced image, or the machine that does the scanning and transmitting.

Federal Communications Commission.

Function or service provided by the system.

Code entered on a dialpad to activate a feature.

Display screen on 4412D+, 4424D+, 4424LD+, and MLX display telephones; provides quick access to commonly used features.

Type of read-only memory provided on the processor module, used to supply system features.

Copper foil sheet (for power units), used to prevent excessive noise on the module.

Condition of the system during certain programming or maintenance procedures; system prevents initiation of new calls.

See FX.

A digital transmission facility consisting of at least one, and fewer than 24, DS0 channels using robbed-bit signaling, and connecting a PBX and a central office or toll office.

One of several segments of an analog or digital signal that has a repetitive characteristic. For example, a DS1 frame consists of a framing bit and 24 bytes, which equals 193 bits.

Pattern of frames used in transmissions.

Facility Restriction Level. Calling restriction type that restricts calls to certain specified ARS and UDP routes.

Foreign Exchange. Central office other than the one that is providing local access to the public telephone network.

G

Condition that occurs when a user tries to call out on a loop-start line at the same time that another call arrives on the same line.

Trunk on which the communications system, after verifying that the trunk is idle (no ground on tip lead), transmits a request for service (puts ground on ring lead) to the telephone company central office.

Fax unit, offering 400 by 100 dots per inch (DPI) in fine mode, that can operate at any speed for communication with a Group III (G3) fax machine or another Group IV (G4) fax machine.

System application that allows face-to-face, simultaneous video and voice communications between groups and requires high-speed data transmission facilities. See also Desktop Videoconferencing System.

H

See HFAI.

Lightweight earpiece and microphone used for hands-free telephone operation.

Hands-Free Answer Intercom. Feature that allows a user to answer a voice-announced call.

Display normally shown on a 44xx or MLX display telephone; shows time, date, and call information, as well as when some features are in use.

Telephone company or other switch providing features and services to the system users, usually when the system is operating in Behind Switch mode.

In a private network that is arranged in a star configuration, the communications system through which all calls across the network pass.

One of three modes of system operation in which the system uses line/trunk pools and ARS in addition to personal lines. Provides a single interface (SA buttons) to users for both internal and external calling. See also Behind Switch Mode and Key Mode.

I

Incoming Call Line Identification. See Caller ID.

Intercom Buttons. Telephone buttons that provide access to inside system lines for calling other extensions or receiving calls from them.

Tie trunk on which no start signal is necessary; dialing can begin immediately after the trunk is seized.

See Robbed-Bit Signaling.

Tone users hear when they are off-hook on an SA or ICOM button.

Display screen on a multiline 44xx or MLX display telephone that allows the user to preview incoming calls and view a list of the features programmed on line buttons.

See ISDN.

See IS III.

Software-controlled processor complex that interprets dialing pulses, tones, and/or keyboard characters and makes the proper interconnections--both inside and outside. Consists of a computer, software, a storage device, and carriers with special hardware to perform the actual connections. Provides voice and/or data communications services, including access to public and private networks, for telephones and other equipment. Also referred to in this guide as "system," short for MERLIN MAGIX Integrated System.

See ICOM Buttons.

Hardware and/or software that links systems, programs, or devices.

In a private network, calls between a local extension and a local or non-local dial plan extension.

Set of integrated applications that provides voice mail, fax messaging, Automated Attendant, call accounting, and system programming.

Voice response application that automatically answers and routes calls and executes telephone transactions.

Input/Output Device. Equipment that can be attached to a computer internally or externally for managing a computer system's input and output of information.

In-Range Out-of-Building protector. Surge-protection device for off-premises telephones at a location within 1000 feet (305 meters) of cable distance from the control unit.

Integrated Solution III. Set of UNIX System-based applications that augments and provides additional services using the system. IS III is no longer available.

Integrated Services Digital Network. Public or private network that provides end-to-end digital connectivity for all services to which users have access by a limited set of standard multipurpose user and network interfaces; provides digital circuit-switched or packet-switched connections within the network and to other networks for national and international digital connectivity.

Integrated Services Digital Network Terminal Adapter. A device that connects the communications system with data terminal equipment (DTE).

   ISDN Terminal Adapter Data Station

Type of data station that includes an ISDN terminal adapter as its DCE. It may also include an MLX telephone for simultaneous voice and data (ISDN terminal adapter data-only station). These data stations connect to MLX extension jack modules for digital transmission of data over a DS1 facility.

J

Physical connection point to the system for a telephone, line/trunk, or other device. Also called "port."

K

kilobits per second.

One of three modes of system operation, in which the system uses personal lines on line buttons for outside calls, with a separate interface (ICOM buttons) for inside calling. See also Behind Switch Mode and Hybrid/PBX Mode.

L

Local Area Network. Arrangement of interconnected personal computers or terminals, which sometimes access a host computer, and sometimes sharing resources such as files and printers.

Listed Directory Number.

Light-Emitting Diode. Semiconductor device that produces light when voltage is applied; light on a telephone.

Connection between extensions within the communications system; often, however, used synonymously with trunk.

Assignment of lines and trunks connected to the system control unit to specific buttons on each telephone.

Pattern that data assumes as it is transmitted over a communications channel.

Adjustment for the amount of cable loss in decibels (dB), based on the length of cable between a 100D module and a channel service unit (CSU) or other far-end connection point.

Refers to inside system lines and outside lines/trunks in general terms. See also Line and Trunk.

Physical interface on a module in the control unit for connecting an outside line/trunk to the communications system. Also called "trunk jack."

Module on which the jacks for connecting central office lines/trunks and/or the jacks for connecting the extensions are located.

In a system that is part of a private network, list of extension ranges that the local system refers to in order to route local intersystem calls via UDP.

In a system that is part of a private network, extension that is listed in the system's local dial plan.

Method for connecting an extension jack to an on-site computer for data-only calls through a modem or ISDN terminal adapter.

The two-way connection between a customer's premises and the central office.

In a private network, person whose extension is connected to the local control unit.

   Logical ID

Unique numeric identifier for each extension and line/trunk jack in the system control unit.

Line on which a closure between the tip and ring leads is used to originate or answer a call. High-voltage 20-Hz AC ringing current from the central office signals an incoming call.

M

Lucent Technologies Music-On-Hold enhancement that promotes a company's products or services.

megabits per second.

AT&T tariffed digital WATS offering for outward calling.

AT&T tariffed digital 800 offering for inward calling.

Storage medium, similar in function to a floppy disk, that allows information to be added to, or obtained from, the communications system through the PCMCIA interface slot on the processor module.

Voice-messaging system that provides Automated Attendant, call answering, and voice-mail services. It is housed in its own module.

See Octel 100.

Multi-Function Module. Adapter that has a tip/ring mode for answering machines, modems, fax machines, and tip/ring alerts, and an SAA mode for -48 VDC alerts. It is installed inside an MLX telephone and is used to connect optional equipment to the telephone. The optional equipment and the telephone operate simultaneously and independently.

An enhanced tip/ring (Series 3) telephone. No longer available.

Multiline button telephone that transmits and receives digital signals.

Streams of touch-tone codes used by voice messaging applications to communicate with the system's control unit.

Device that converts digital data signals to analog signals for transmission over a telephone line, and analog signals received on a telephone line to digital signals.

Type of data station that includes a modem as its DCE. It may also include an MLX telephone for simultaneous voice and data (MLX voice and modem data station), an analog multiline telephone (analog voice and modem data station), or a single-line telephone for dialing only (modem data-only station). These data stations connect respectively to MLX, analog, or tip/ring extension jack modules. They provide analog transmission of data.

Pair, or group of pairs, of modems and data modules with interconnected RS-232 interfaces that converts digital signals to analog, or analog signals to digital, thereby allowing users with ISDN terminal adapter data stations to communicate with users who have analog modem data stations.

Circuit pack in the control unit that provides the physical jacks for connecting telephones and/or outside lines/trunks to the communications system. In the name of a module, the first digit indicates the number of line/trunk jacks it contains; the last digit indicates the number of extension jacks it contains. If no letters appear after the number, a line/trunk module provides loop-start lines or an extension jack module provides analog or tip/ring jacks. For example, a 408 GS/LS-MLX module contains four line/trunk jacks and eight digital (MLX) extension jacks, and provides either loop-start (LS) or ground-start (GS) trunks.

Extension for which one or more CTI applications is receiving call information. The CTI application does not have to be directly attached to the equipment at the extension in order to monitor calls. The call information may appear on the PC screen of another extension that has been programmed to receive it. See also CTI Link and Unmonitored Extension.

See MFM.

Telephone that provides multiple line buttons for making or receiving calls or programming features.

Division of a transmission channel into two or more independent channels--either by splitting the frequency band into a number of narrower bands or by dividing the channel into successive time slots.

Customer-provided music source or Magic On Hold connected to the system through a loop-start jack.

N

Configuration of communications devices and software connected for information interchange.

Hardware, software, or both that links two systems in an interconnected group of systems--for example, between the local telephone company and a PBX.

National Integrated Services Digital Network 1 Basic Rate Interface. Type of digital facility that carries the equivalent of three lines. Two are called B-channels and provide voice and data communications services. A third D-channel controls signaling and maintains operations on the B-channels.

In a system that is part of a private network, list of extension ranges that the local system references in order to route non-local intersystem calls via UDP.

In a system that is part of a private network, extension that is in the non-local dial plan.

In a private network, user who is connected to another system in the network and not to the local system.

In a private network, communications system that is directly connected to and located more than 200 miles from the local system.

O

Voice-messaging system housed in a PC that connects to tip/ring ports on the system's modules. Octel 100 Messaging provides voice mail, Automated Attendant, call answering, and fax messaging services.

Telephone is said to be off-hook when the user has lifted the handset, pressed the speakerphone button to turn on the speakerphone, or used a headset to connect to the communications system or the telephone network.

See OPT.

Requirement for channelized DS1 service to the public network that prohibits eight consecutive zeros in a digital data stream.

Telephone is said to be on-hook when the handset is hung up, the speakerphone is turned off, and the user is not using a headset to connect to the communications system or the telephone network.

Off-Premises Telephone. Single-line telephone or other tip/ring device connected to the system via a 008 OPT module in the control unit. Appears as an inside extension to the system, but may be physically located away from the system.

Off-Premises Extension.

Signaling that uses the same path as voice-frequency transmission and in which the signaling is outside the band used for voice frequencies.

P

Addition of a bit to a bit string so that the total number of ones is odd or even; used to detect and correct transmission errors.

Set of software applications that provides an interface between a personal computer and an MLX telephone.

Private Branch Exchange. Local electronic telephone switch that serves local stations (for example, extensions within a business) and provides them with access to the public network.

Personal Computer.

Personal Computer Memory Card International Association Memory Card. See Memory Card.

In a private network, system that does not connect to more than one other system, sometimes called an "end node."

Central office line/trunk that terminates directly at one or more extensions. In Hybrid/PBX mode, a personal line cannot be part of a line/trunk pool. Also called "DFT" (Direct Facility Termination).

Power Failure Transfer. Feature that provides continuity of telephone service during a commercial power failure by switching some of the system's line/trunk connections to telephones connected to specially designated extension jacks.

Extension that is not actually plugged into the system, but is used, for example, as a calling group member covered by a voice messaging system.

In Hybrid/PBX mode, a group of outside lines/trunks that users can access with a Pool button or by dialing an access code on an SA button. Also used by the ARS feature when choosing the least expensive route for a call.

In a private network, a line/trunk that passes through the PSTN without using the switching capabilities of the PSTN.

See Jack. Also, refers to extension or line/trunk jacks before these are numbered according to the dial plan during programming. The lowest jack on a module is always Port 1.

See PFT.

Device that directs electricity to modules and telephones on the system. One power supply module is needed for each carrier.

Primary Rate Interface. Standard interface that specifies the protocol used between two or more communications systems. As used in North America, it provides twenty-three 64-kbps B-channels for voice and/or data and one 16-kbps D-channel, which carries multiplexed signaling information for the other 23 channels.

First extension jack on the first TDL or MLX module in the control unit--that is, the extension jack with the lowest logical ID in the system.

Individual extension number assigned to a telephone in a system operating in Behind Switch mode. Each telephone user has his or her own prime line and is automatically connected to that line when he or she lifts the handset.

System function that prioritizes calling groups, thereby allowing certain incoming calls to be answered before others.

See Private Network.

Interconnected group of communications systems, which may consist of MERLIN MAGIX Integrated Systems, MERLIN LEGEND Communications Systems, DEFINITY Enterprise Communications Servers (ECS), DEFINITY Business Communications Servers (BCS), and/or DEFINITY ProLogix Solutions.

Facilities that connect communications systems in a private network. See also Tandem Tie Trunk and Tandem PRI Trunk.

Module in the second slot of the control unit (Slot 0, to the right of the power supply module). Includes the software and memory that runs the system.

Reassignment of the system programming jack position to any of the first five extension jacks on the first TDL or MLX module in the control unit.

Set of conventions governing the format and timing of message exchanges between devices, such as an MLX telephone and the control unit.

Public Switched Telephone Network. Network that is commonly accessible for local or long-distance calling. Also called "public network" or "public switched network."

In a private network, facility that connects a networked system to the public switched telephone network.

See PSTN.

Q

Queued Call Console. A 4424LD+ or MLX-20L telephone used by a system operator in Hybrid/PBX mode only. Used to answer outside calls (directed to a system operator position) and inside calls, to direct inside and outside calls to an extension or to an outside telephone number, to serve as a message center, to make outside calls for users with outward calling restrictions, to set up conference calls, and to monitor system operation.

R

Random-Access Memory. Computer memory in which an individual byte or range of bytes can be addressed and read or changed without affecting other parts of memory.

See ROM.

System feature that allows an outside caller to gain access to the system, almost as if at a system extension. In a private network, remote access settings are used to control calls routed via ARS or UDP routing across the network.

   Restore

Procedure whereby saved and archived system programming is reinstated on the system, from a floppy disk or memory card. See also Backup.

Channels that do not allow the transmission of occurrences of more than seven contiguous zero bits. See also Unrestricted Data Channels.

Through centralized programming, T/R ports (including the T/R ports on the new ETR modules) can be programmed to accept rotary-dial and touch-tone digits or just Touch-Tone digits.

Cable that runs between floors in a multi-story building and connects wiring closets.

Physical interface, specified by the Electronics Industries Association (EIA), that transmits and receives asynchronous data at distances of up to 50 feet
(15 meters).

Signaling in which the least significant bit of every sixth frame per channel is used for signaling in that channel.

Read-Only Memory. Computer memory that can be read, but cannot be changed.

S

Telephone buttons that provide access to both inside and outside calls.

In a private network, a communications system that is directly connected to, and located within 200 miles of the local system.

Refers to a computer-telephony software application that takes caller information (for example, the calling party number provided by Caller ID service), queries a database, and displays a screen with information about the caller onto a user's PC screen. Screen pop requires that an identifying number or code be available to identify the calling party. See also CTI Link.

Software Defined Network. AT&T private networking service created by specialized software within the public network.

Private network arrangement whereby either two or four or more communications systems are connected in a line, with no particular system acting as the hub system. See also Star Configuration.

Feature that allows one extension to listen in (observe) on calls that arrive at another extension.

Station (Extension) Identification.

Sending of information between devices to set up, maintain, or cease a connection, such as a telephone call.

Transmission of signals in one direction only, across a telecommunications channel.

Industry-standard touch-tone or rotary dial telephone that handles one call at a time. It is connected to the system via an extension jack on a 016 (T/R) or 008 OPT module, or via a port on an 016 ETR module programmed for tip/ring operation.

Position in a carrier for a module; numbered from 0.

Station Message Detail Recording. Feature that captures usage information on incoming and outgoing calls.

Printer used to produce SMDR reports. Connected to the system via an RS-232 jack on the processor module.

See SDN.

Pause, Stop, or End-of-Dialing signal in a programmed dialing sequence, such as a speed dial number.

Configuration in Key mode operation in which all outside lines appear on all telephones.

Private network arrangement whereby either three or more communications systems are connected with one system acting as the hub system. See also Series Configuration.

See Extension.

See Extension Jack.

See SMDR.

See Integrated System.

DS1 Switched 56 service is an end-to-end digital, 56-kbps, full-duplex, synchronous, circuit-switched service offering. The service is offered by network service providers and by some Local Exchange Carriers (LECs) as circuit-switched, 56-kbps service. T1-emulated tandem tie trunks in a private network can be programmed for data.

Momentary (320 ms to 1 sec) on-hook signal used as a control; may be directed to the control unit or to a host switch outside the system. Also called "Recall" or "timed flash."

Number assigned to a tandem trunk in a private network. It identifies the system connected to the far end of the trunk. A switch identifier is based on the type of system and its distance from the system where the identifier is assigned. See also Satellite System and Non-Satellite System.

   Synchronous Data Transmission

Method of transmitting a continuous digital data stream in which the transmission of each binary bit is synchronized with a master clock. See also Asynchronous Data Transmission.

Test of all trunks, telephones, data terminals, and features after installation to ensure that they are working correctly.

See SA buttons.

Date and time that appear on 44xx, MLX, and ETR display telephones and SMDR reports.

Programming of system functions and features that affect most users, performed from a 4424LD+ or MLX-20L telephone or a computer using WinSPM. See also Extension Programming and Centralized Telephone Programming.

See WinSPM.

Procedure used to change the numbers assigned to telephones, adjuncts, calling groups, paging groups, park zones, Remote Access, and lines/trunks.

T

Type of digital transmission facility that, in North America, transmits at the DS1 rate of 1.544 mbps.

A T1 tie trunk programmed for S56DATA for use by data calls at speeds up to 56 kbps. These trunks may be used for tandem and non-tandem operation.

A T1 tie trunk programmed for Tie-PBX or Tie-Toll for use by voice calls.

   T1 Switched 56 Service

T1 digital data transmission over the public network or over a private network at 56 kbps. See Switched 56 Service.

Capability of private network communications systems that allows them to direct outside calls from one facility to another, rather than just to an extension. Calls may be sent, for example, from a PSTN facility to a tandem trunk, or vice versa.

Private outside facility (as opposed to an inside system line) that connects two communications systems in a private network and can carry calls to another outside facility through tandem switching. The trunk is not connected to the PSTN.

Tandem trunk that is an analog delay-start tie trunk, providing a single line/trunk per facility and allowing analog transmission of voice and low-speed data; or a T1 facility offering 24 channels on emulated tie trunks and programmed for voice or data.

Tandem Primary Rate Interface Trunk. Private network trunk.

Telephony Application Programming Interface. Application programming interface that allows computer telephony applications to be used with MLX telephones. See also Passageway Direct Connection Solution.

Equipment that provides power to an individual telephone.

See ISDN Terminal Adapter.

Private trunk directly connecting two telephone switches.

See Switchhook Flash.

Contacts and associated conductors of a single-line telephone plug or jack.

See TTR.

See Tip/Ring.

Telecommunications path between the communications system and the telephone company central office or another switch. Often used synonymously with line.

See Line/Trunk Jack.

See Pool.

Telephony Services Application Programming Interface. Application programming interface that allows computer telephony applications to be used. See also TAPI and CTI Link.

Touch-Tone Receiver. Device used to decode DTMF touch-tones dialed from single-line or Remote Access telephones.

U

Uniform Dial Plan. Composed of the local dial plan and non-local dial plan. A dial plan that allows a caller at any extension in a private network to dial the same number of digits to reach any other extension in the private network, even if the originating extension is physically connected to one communications system and the terminating extension is physically connected to a different communications system.

Practice of numbering of extension ranges, remote access codes, or other system components to avoid routing conflicts in network or local calling. For example, Extension 441 is unique when compared to Extension 4410; however, this is ambiguous, because the system routes as soon as it matches the digits sent for a call with the digits in a local dial plan or in a non-local dial plan extension range. When a caller dials 4410, therefore, the system routes the call to Extension 441 without considering the last dialed digit.

See UDP.

See UPS.

Measure of the power load drain of a module, telephone, or adjunct.

Extension for which no CTI application is receiving call information. See also CTI Link and Monitored Extension.

Also called Clear Data Channels. Allow the transmission of occurrences of more than seven contiguous zero bits. If an unrestricted data channel is requested and only restricted channels are available, the call will be rejected. See also Restricted Data Channel.

Uninterruptible Power Supply. Device that connects to the system to provide 117 VAC to the equipment when the commercial power source fails.

V

Alternating Current Voltage.

Direct Current Voltage.

Voice Messaging Interface. Enhanced tip/ring port.

System application that allows face-to-face meetings, with voice and video, between individuals or groups. This application requires high-speed data transmission facilities. See also Desktop Videoconferencing System and Group Videoconferencing System.

See VPN.

Virtual Private Network. Type of private network that uses the switching capabilities of the PSTN, rather than tandem switching, to direct calls between connected communications systems. A VPN may constitute a part of a private network.

System feature that allows users to receive voice announcements on their telephones. In Release 7.0 and later systems, the VA On Idle Only option (only for MLX telephones) allows voice announcement calls to go through only when the telephone is idle.

Transmission channel, generally in the 300-3400-Hz frequency band.

Application that allows users to send messages to other system extensions, to forward messages received with comments, and to reply to messages.

See VMI.

W

Wide Area Telecommunications Service. Service that allows calls to certain areas for a flat-rate charge based on expected usage.

Tie trunk on which the originating end transmits an off-hook signal and waits for the remote end to send back a signal (a wink) that it is ready for transmission.

Windows System Programming and Maintenance. Windows-based application for programming the system.

XYZ