(Page 1 of 1 in this chapter)
Appendix A
Glossary
- 2500-type telephone The standard single-line touchtone telephone desk set.
- A bit One of four bits used to carry signaling on MVIP signaling streams. The others are called the B, C and D bits. Many protocols do not use all four bits. Usually, only the A and B bits are used in North America, while all four are used in Europe.
- A-law An encoding scheme that determines how an analog speech signal is converted to a digital signal. A-law encoding is used in Europe. The other algorithm, mu-law, is used in North America and Japan. See also mu-law.
- ABCD bits The signaling bits. The value that these bits take determines or indicates the state of the telephone line.
- ADI service The CT Access service that provides all AG device-level functionality. The ADI service is supported by Natural MicroSystems' AG boards. Functions are provided for establishing and maintaining network connections, determining call status, playing and recording voice messages, and generating and detecting DTMF and other tones.
- AG Natural MicroSystems' Alliance Generation product line of telephony and voice processing hardware and software, including highly integrated hardware modules.
- AG configuration file Text file that provides configuration information for all AG boards in your system, including runtime software such as DSP files and TCPs to download to the AG board(s). agmon uses the AG configuration file to initialize the AG board driver and configure your boards. See also agmon, DSP file, TCP.
- AG driver The hardware device driver that allows CT Access to communicate with all AG boards in a host system.
- agmon Utility program which reads a configuration file and uses it to load and monitor the AG hardware.
- analog Information represented by a continuous and smoothly varying signal amplitude or frequency. Opposite of digital.
- API Application Programming Interface; a library of function calls that allow an application developer to access functionality in a uniform and consistent way.
- ASCII American Standard Code for Information Interchange; a standard used for numeric representation of alphanumeric characters.
- asynchronous Refers to circuitry and operations without a common timing or clock signal.
- B bit See A bit.
- bit An acronym for binary digit; the smallest piece of information; a specification of one of two possible alternatives: zero or one.
- blocking system A switching system that does not have enough switching capability to allow all possible sets of connections to be made. Under some circumstances, a connection cannot be made and the call is said to be blocked.
- bus A physical system which permits the interchange of data. A telephony bus has three basic elements: lines for the data, bit synchronization (clocks), and frame synchronization (frame strobe). Most telephony busses also have a network reference - an 8 kHz timekeeper. See also MVIP, H.100.
- C bit See A bit.
- clock A timing reference signal, e.g., on an MVIP bus.
- clock master The board that sources the clocks in an MVIP system.
- clock slave A board that derives its clock signal from a bus cable; the clock signal is driven by the bus clock master.
- connection (MVIP) Connects an input terminus to an output terminus. The input and output terminuses can have the same or different buses and streams.
- coprocessor A microprocessor on the AG board. Runs manager code to enable high level communication between the host and the other AG board resources (DSP and MVIP).
- crosstalk Undesired voice-band energy transfer from one circuit to another (usually physically adjacent).
- CT Access Natural MicroSystems' development environment for telephony applications.
- D bit See A bit.
- dB See decibel.
- dBm A unit of measure of absolute power level, defined as the number of decibels above or below a level of one milliwatt.
- decibel (dB) A unit of measure of relative power or voltage in terms of the ratio of two values. dB = 10 log (P1/P2), where P1 and P2 are the power level in watts.
- DID Direct Inward Dialing; an incoming telephone service which delivers the final portion of the called address to the CPE, thus allowing the caller to reach an individual extension of a PBX.
- DID number Direct Inward Dial number; the called number which is collected by the trunk control program and is passed back to the application.
- digital Information in a discrete or quantized form. Opposite of analog.
- Digital Signal Processor
See DSP.
- DLL Dynamic Link Library; a library of software object modules that can be loaded and accessed on demand.
- DRAM Dynamic Random Access Memory chip; RAM memory that requires data to be refreshed periodically to prevent its loss in memory. See also SRAM.
- DSi0..7, DSo0..7 MVIP-90 nomenclature for the individual unidirectional bit streams on the MVIP bus. By convention, they are paired up (DSix, DSox) to form the eight full duplex MVIP streams. DSi0..7 are designated for input to resource boards and DSo0..7 are designated for output from resource boards.
- DSP Digital Signal Processor; a microprocessor that is designed to perform the calculations required for voice processing.
- DSP files Low-level programs downloaded to an AG board at initialization that enable an AG board's on-board DSPs to perform tasks such as DTMF signaling, voice recording, and playback.
- DTMF Dual-Tone-Multi-Frequency; an in-band signaling system that uses two simultaneous voice-band tones for dialing. Also called touchtone.
- Dynamic Random Access Memory
See DRAM.
- E&M A telephone signaling system used between two switches that uses two wires called the E lead and the M lead. In analog E&M, the M lead of one switch is connected to the E lead of the other, and vice versa. In digital E&M signaling, the A bits and B bits are used.
- echo cancellation An algorithm for analyzing data output on the line so that it can be removed from the received signal.
- ELS See enhanced loop start.
- encoding (speech) Any of the compression techniques for digitizing and compressing speech data.
- enhanced loop start hybrid (ELS)
An NMS line interface hybrid that provides on-hook monitoring of line at normal audio levels. The enhanced loop start hybrid offers improved logging for line calls and better signal to noise detection and than the standard loop start hybrid.
- enhanced switching compliant
See MVIP Enhanced Switching Compliant.
- events In CT Access, data structures that contain notification of certain conditions or state changes sent from the hardware or service to the application program. All CT Access events are represented as a C data structure. The structure informs the application what event occurred and provides additional information specific to the event.
- FMIC A Flexible MVIP Interface Circuit, which provides a digital timeslot switch and an MVIP bus interface.
- forward connection A full duplex connection between a DSP resource and a network interface. See also full duplex, reverse.
- four-wire In analog telephony, a connection that requires four physical conductors for the voice path, one pair for each direction. If additional wires are required for signaling, they are not counted. In digital telephony, a connection that requires two channels or timeslots, one for each direction. See also two-wire.
- full duplex Simultaneous two-way voice and two-way signal data transmission. See also half-duplex and simplex.
- gain (play, record) An amplitude scaling (in dB) applied to played speech after decompression or to recorded speech prior to compression.
- ground An electrical connection to earth or to a common conductor which is connected to earth.
- H-MVIP The hardware standard for MVIP-95.
- H.100 bus A PCM digital bus standard for integrating various board vendors. Allows boards to share data, signaling and switching information. It is an interoperable superset of the H-MVIP and MVIP-90 telephony busses.
- half-duplex A circuit that can carry information in both directions, but only in one direction at a time. See also full duplex and simplex.
- Hertz (Hz) The unit of frequency. One hertz equals one cycle per second.
- host The PC CPU where the host application runs.
- hybrid A circuit that interfaces a bidirectional transmission channel to separate receive and transmit channels.
- Hz See Hertz.
- in-band Audio (voice) path of a telephone line interface.
- ISA Industry Standard Architecture; the de-facto bus card standard in the IBM-PC compatible world. Also known as the PC/AT bus.
- line A logical telephone connection on which a call can take place.
- loopback Connecting the input and outputs of a device locally. This is typically used for testing purposes.
- loop start (LS) A method of signaling an off-hook or line seizure, where one end closes the loop circuit and the resulting current flow is detected by the switch at the other end.
- megahertz A unit or measure (MHz), used to quantify band and bandwidth, that denotes one million Hertz (cycles per second).
- MF Multi-Frequency; an in-band interoffice tone-based signaling method using pairs of frequencies from a set of six available frequencies.
- MIPS Millions of Instructions Per Second; measure of computer speed according to the average number of machine language instructions performed by the CPU in one second.
- mu-law One of two algorithms used in telephony to logarithmically compress or expand digitized speech. mu-law is used in North America and Japan. A-law is the other algorithm used in European networks. See also A-law.
- multiplexing The transmission of two or more channels on a single physical circuit.
- MVIP Multi-Vendor Integration Protocol; PCM digital bus standard for integrating various board vendors. Facilitates software-controlled digital switching within the PC chassis. MVIP interconnects switching and telephony processing boards on a PC.
- MVIP bus A high-speed, multiplexed digital telephony "highway" which allows boards to share data, signaling information, and switching information.
- MVIP connection See connection (MVIP).
- MVIP Enhanced Switching Compliant Device
A network device with a switch implementing all possible connections of the MVIP switch model.
- MVIP Standard Switching Compliant Device
A network device with a switch that does not implement the full MVIP switch model but does support port-to-MVIP connections for all MVIP timeslots, both forward and reverse.
- MVIP Switching Compatible Device
A network device with an MVIP switch that does not fully meet the MVIP standard or MVIP enhanced compliance standards.
- MVIP switch model An abstract representation of the most general switching capabilities that can be located on one network interface device. However, a particular network interface device need not implement all of the switching capabilities of the switch model.
- MHz See megahertz.
- nail up To make a permanent assignment, as in nailing up a connection.
- NMS Natural MicroSystems Corporation.
- NOCC (Null Protocol) NO Call-Control; the trunk control program used when the application will not use protocol-independent call control. NOCC is a stateless protocol which does not generate any call control events. It is typically used with low level functions which enable applications to perform call control from the host.
- non-blocking system A switching system with enough switching capability to allow all possible sets of connections to be made. See also blocking system.
- off-hook The active state of a customer telephone circuit. The term is derived from old telephone sets where the receiver, when in use, was lifted from a hook attached to a switch. The opposite condition is on-hook.
- out-of-band Information carried outside of the audio or voice channel.
- overlay Software that is not always memory resident; it is loaded on request.
- pattern An 8 bit sample that is sent out of an output terminus or into an input terminus of a switch block.
- PCM Pulse Code Modulation; a communication technique where the information to be sent is converted into binary numbers which are then transmitted on the signal.
- port An external connection between the MVIP bus and anything else, including telephone trunks, human operators, voice processors, fax processors, etc.
- protocol (telephony) Defined procedure for call setup and call teardown.
- protocol-independent Used to describe a call control model. All telephony protocols can be represented by this single call control model.
- PSTN Public Switched Telephone Network; a public telephone network.
- Pulse Code Modulation
See PCM.
- reverse connection A full duplex switch connection between two network interfaces. See also forward connection.
- ring The alerting signal to the subscriber or terminal equipment; also the name for one conductor of a wire pair, designated by R. The other is called tip, or T. See also tip.
- routing The process of finding an available path or sequence of paths that create a desired connection.
- runfile Low-level software which an AG board requires to operate.
- services In CT Access, a group of logically related telephony functions. A service may be implemented on multiple hardware boards. No matter what hardware is providing the functionality, all services with the same functionality have a standard API. This allows device independent programming.
- signaling The transmission of information about a line's on-hook or
off-hook status and various related signals including those that deliver address information.
- simplex A circuit which carries information in only one direction.
- SRAM Static Random Access Memory; RAM that retains its data without the refreshing required by DRAM. SRAM offers faster memory access time and is more expensive than DRAM. See also DRAM.
- standard switching compliant
See MVIP Standard Switching Compliant Device.
- Static Random Access Memory
See SRAM.
- stream A grouping of timeslots that usually corresponds to a particular bit-stream of time-domain multiplexed (TDM) serial data on an individual track or wire of a bus.
- switch In telephony, a device that can connect one of several inputs to one of several outputs. Switches can range in size from an integrated circuit to an entire build-ing.
- switch block The switch on boards that interface the telephone network to the MVIP bus. This switch is normally referred to as the switch block because it may consist of one or more physical switches. It may be either MVIP-compatible or MVIP-compliant.
- switching Changing the connections on different boards within a PC platform both during and between phone calls.
- switching card A circuit card (board) which contains an MVIP switch block. Since MVIP switching is distributed, systems may contain several switching cards. A given connection may involve more than one switch block on different switching cards.
- switching compatible See MVIP Switching Compatible.
- Switching service A CT Access service that provides a set of functions for controlling Multi-Vendor Integration Protocol (MVIP) switch blocks on MVIP compliant switching devices. This service is based on the MVIP-95 device driver standard. It may be used to access MVIP-95 and MVIP-90 device drivers.
- synchronous function A function that does not return until its operation is complete.
- task processor A single DSP chip on a hardware board. Each task processor is configured to run one or more overlays (downloadable DSP software modules).
- TCP Trunk Control Program; a module that is downloaded from the host computer to the telephony board which contains the low-level code to interface with an analog or digital trunk running a certain protocol. TCPs are specific to a trunk protocol, for example, one-way inbound with wink start (which is used for DID and DNIS).
- TDM Time Division Multiplexing; a technique for transmitting a number of separate data, voice, and/or video signals simultaneously over one communications medium by quickly interleaving a piece of each signal one after another.
- Telephony Services Architecture
See TSA.
- terminus In the CT Access Switching service, a single access point to a switch block input or switch block output. A terminus contains a bus, a stream, and a timeslot.
- time division multiplexing
See TDM.
- timeslot Specifies a particular 64 kbit/second sub-division of a TDM bus stream. Timeslots number from zero (0) to n where n is stream-dependent.
- tip One conductor of a wire pair, designated by T; usually the more positive of the two. The other is called ring. See also ring.
- TMS320 A digital signal processor produced by Texas Instruments and used on the AG board.
- tri-stated The condition of a logic circuit whose output is in the high impedance state. Most electronic logic circuits try to force their output voltage to be either high or low. Some circuits have a third option which is to present a high output impedance, effectively disconnecting them electrically from the output line. This allows multiple outputs to be safely connected to one line, forming a bus.
- trunk A transmission channel connecting two switching machines.
- Trunk Control Program
See TCP.
- trunk signaling See signaling.
- TSA Telephony Services Architecture; the NMS model of managing telephony and media functionality in computer systems.
- two-wire In analog telephony, a connection that requires only two physical conductors. See also four-wire.
- voice-grade line A local loop, or trunk; a 4 kHz channel having an audio bandpass of approximately 300 to 3200 Hz.
- Voice Message service
A CT Access service that provides a set of functions for playing, recording, and editing voice messages in files or memory.
- wink An out-of-band signaling method that simulates an off-hook condition for a brief period.
(Page 1 of 1 in this chapter)
tech_support@nmss.com
Copyright © 1998, Natural MicroSystems, Inc. All rights
reserved.