Multitech MTA128ST-USB Guía de usuario descargar pdf (Pagina 60)

Glossary

MTA128ST/NT 60

busA common channel between hardware devices, either inter-

nally between components in a computer, or externally between

stations in a communications network.

byteA unit of information consisting of eight binary digits (bits).

A byte holds the equivalent of a single or character (such as the

letter A).

Call BumpingTA feature that reallocates the second B-channel to

an analog port when both B-channels are in use. If you are perform-

ing a data transfer using both channels and need to make a phone

call, one channel is dropped to handle the call and then is reestab-

lished after it is completed. With call bumping you dont miss any

calls.

call setup timeThe time to establish a circuit-switched call

between two points. Includes dialing, wait time, and central office

long distance service movement time.

carrier signalAn analog signal with known frequency, amplitude

and phase characteristics used as a transport facility for useful

information. By knowing the original characteristics, a receiver can

interpret any changes as modulations, and thereby recover the

information.

CentrexA multi-line service, offered by telephone companies,

that provides functions and features comparable to those of a PBX

for large business users. See also PBX, exchange.

channelA data communications path between two computer

devices. It can refer to a physical medium (e.g., UTP or coax), or to

a specific carrier frequency. In ISDN, two types of channels are

specified: transparent (user can define the service), and

nontransparent (service is assigned protocols for specific network

functions). ISDN channel names are designated by a single letter,

from A through M, sometimes combined with a number (see B-

channel and D-channel).

CHAP(Challenge Handshake Authentication Protocol)Security

method used to verify the identity of a person or process.

CHAP MD5Chap with MD5 digital signature algorithm imple-

mented.

circuit-switched networkA technology used by the PSTN that

allocates a pair of conductors for the exclusive use of one communi-

cation path. Circuit switching allows multiple conversations on one

talk path only if end users multiplex signals prior to transmission.

circuit switchingThe temporary connection of two or more

communications channels using a fixed, non-shareable path through

the network. Users have full use of the circuit until the connection is

terminated.

CO (central office)The lowest, most basic, level of switching in

the PSTN (public switched telephone network). A business PABX or

any residential telephone connects to the PSTN at a central office.

COM portA serial communications port on a personal computer.

Normally, there are two: COM1 and COM2.

CPE (customer premise equipment)The generic term for data

communications and/or terminal equipment that resides at the user

site and is owned by the user (e.g., not telephone company equip-

ment).

DCE (data communications equipment)Any device that serves as

the port of entry from the user equipment to a telecommunications

facility. A modem is a DCE for the telephone network (PSTN) that is

commonly on site at the users premises. Packet Switched Networks

have another level of DCE that is most often located at a central

office.

D-channelA non-ransparent digital ISDN channel that operates at

16K or

64 Kbps, used for call control signalling, along with one or more B-

channels. The D (demand) channel signal can control call setup, call

teardown, and invocation of Supplementary Services. Is also used

for telemetry and for low-speed, low-priority packet-switched data.

Contrast with B-channel.

defaultA preset value or option in software packages or in hard-

ware configuration that is used unless you specify otherwise.

device driverSoftware that controls how a computer communi-

cates with a device, such as a printer or mouse.

digital dataInformation represented by descrete values or condi-

tions (contrast analog data).

digital PBXA private branch exchange that operates internally on

digital signals. See also exchange.

digital signal A discrete or discontinuous signal (e.g., a sequence

of voltage pulses). Digital devices, such as as a series of electrical

pulses that have discrete jumps rather than gradual changes.

digital transmissionA method of electronic information transmis-

sion common among computers and other digital devices. Because a

digital signal may be only high or low at any given time, noise and

distortion can easily be removed from digital transmissions.

digitizeTo convert an analog signal to a digital signal.

DIP switchPronounced dip switch. A set of tiny toggle switches,

built into a DIP (dual in-line package), used for setting configurable

parameters on a printed circuit board.

DN (directory number)The phone number assigned to an ISDN

TA at subscription time. It is a string of up to 24 characters, consist-

ing of the valid dialing characters (0-9, *, and #).

driverA software module that interfaces between the operating

system and a specific hardware device (e.g., color monitors, printers,

hard disks, etc.). Also known as a device driver.

DTE (data terminating equipment)A term used to include any

device in a network which generates, stores or displays user infor-

mation. DTE is a telecommunications term that usually refers to

PCs, terminals, printers, etc.

DTMF (dual-tone multifrequency)A generic push-button concept

made popular by AT&T TouchTone.

DTMF detectionA capability in some fax/data modems that can

differentiate between DTMF or fax calling tones. A typical applica-

tion would be a program that routes calls to specific communica-

tions applications, depending either on the type of call or on a

DTMF tone added to a dialing string.

EEPROM (Electrically Eraseable Programmable Read-only

Memory)Upgradable memory chip often used to store firmware.

EISA (Enhanced Industry Standard Architecture)Pronounced

eesa. The purpose of the EISA bus is to provide a 32-bit bus for

faster throughputs while maintaining backward compatibility with

the classic ISA bus architecture.

ET (exchange termination)The carriers local exchange switch.

Contrast with LT (loop termination).

exchangeA unit (public or private) that can consist of one or more

central offices established to serve a specified area. An exchange

typically has a single rate of charges (tariffs) that has previously

1 2 ... 55 56 57 58 59 60 61 62 63 64 65 66

Comentarios a estos manuales

Sin comentarios

Multitech MTA128ST-USB Guía de usuario Pagina 60

Comentarios a estos manuales