ISDN Protocol Administrator's and Developer's Guide ... - Intervoice

compandingA transmission procedure that compresses voice signals forefficiency on the sending end and then expands them on thereceiving end.ConnectLinkA software module that enables data communications with anIntervoice system over a telephone line or a network link.ConnectLink allows connectivity between nodes in a multiple-nodesystem, between separate systems, or between a system and a remotehost.CSU (channel service unit)A device, such as a PBX, that connects a digital phone line whichcomes in from a telephone company to an external digital circuit. ACSU terminates the external line at the customer’s premises.d1.mrkA file that contains information on all files in an InVisionapplication. This file must be present in the application subdirectoryfor InVision to open the application. This file also aids with thestamping and certification processes. Its checksum digit enables theverification utility to determine whether changes were made to theapplication after stamping or certification.D channelA channel that carries control signals and customer call data in apacket. This packet contains setup, teardown, ANI, and other callcharacteristics for the ISDN interface. The data in the packetchanges as the call changes. Also referred to as a data channel.DCE (data communications equipment)One of two termination types for RS-232 communications lines.DCE communicates with Data Terminal Equipment (DTE).DID (direct inward dialing)A method of digit transmission in which the telephone companyswitch seizes the PBX main phone line and then sends the extensiondigits to the PBX when it answers. This makes it possible for callersto dial various people and services over a single trunk group.digital signalA signal that carries information in a stream of on/off pulses (binary1s and 0s). Digital signals are often used for data transmission.Analog signals can be converted to digital signals. See also analogsignal.60001262, First Edition ISDN Protocol Administrator’s and Developer’s Guide Glossary-3