Administrator's Guide

Glossary and abbreviations
555-233-5061968 Issue 5 October 2002
DOSS
Delivery Operations Support System
DOT
Duplication Option Terminal
DPM
Dial Plan Manager
DPR
Dual-port RAM
DS1
Digital Signal Level 1
DS1C
Digital Signal Level-1 protocol C
DS1 CONV
Digital Signal Level-1 converter
DSI
Digital signal interface
DSU
Data service unit
DTDM
Digital-terminal data module
DTE
Data-terminal equipment
DTGS
Direct Trunk Group Select
DTMF
Dual-tone multifrequency
DTS
Disk-tape system
duplicated common control
Two processors ensuring continuous operation of a communications system. While one processor is online,
the other functions as a backup. The backup processor goes online periodically or when a problem occurs.
duplication
The use of redundant components to improve availability. When a duplicated subsystem fails, its backup
redundant system automatically takes over.
duplication option
A system option that duplicates the following: control carrier containing the SPE, EI circuit packs in carriers,
fiber-optic cabling between port networks, and center-stage switch in a CSS-connected system.
DWBS
DEFINITY Wireless Business System
DXS
Direct extension selection