Instruction manual

DEFINITY® Business Communications System and GuestWorks® Issue 6
Overview
555-231-208
Issue 1
April 2000
Glossary and Abbreviations
GL-11
data terminal equipment (DTE)
Equipment consisting of the endpoints in a connection over a data circuit. In a connection between
a data terminal and host, the terminal, the host, and their associated modems or data modules
make up the DTE.
DC
Direct current
DCE
Data-communications equipment
D-channel backup
A type of backup used with Non-Facility Associated Signaling (NFAS). A primary D-channel
provides signaling for an NFAS D-channel group (two or more PRI facilities). A second D-channel,
on a separate PRI facility of the NFAS D-channel group, is designated as backup for the D-channel.
Failure of the primary D-channel causes automatic transfer of call-control signaling to the backup
D-channel. The backup becomes the primary D-channel. When the failed channel returns to
service, it becomes the backup D-channel.
DCP
Digital Communications Protocol
DDC
Direct Department Calling
DDD
Direct Distance Dialing
delay-dial trunk
A trunk that allows dialing directly into a communications system (digits are received as they are
dialed).
designated telephone
The specific telephone to which calls, originally directed to a certain extension, are redirected.
Commonly used to mean the forwarded-to telephone when Call Forwarding All Calls is active.
dial tone
A continuous tone indicating that a user can dial a number or activate features.
dial-repeating trunks
A PBX tie trunk that is capable of handling PBX station-signaling information without attendant
assistance.
dial-repeating tie trunk
A tie trunk that transmits called-party addressing information between two communications
systems.
DID
Direct Inward Dialing
digit conversion
A process used to convert specific dialed numbers into other dialed numbers.
digital
The representation of information by discrete steps. See also analog
.
digital communications protocol (DCP)
A proprietary protocol used to transmit both digitized voice and digitized data over the same
communications link. A DCP link is made up of two 64 kbps information (I-) channels and one 8
kbps signaling (S-) channel. Digital Communications Protocol. The DCP protocol supports two