D channel 

ISDN channel used to carry signaling

DACS 

Digital Access and Crossconnect System

D-AMPS 

Digital Advanced Mobile Phone Service (IS-136)

DAS 

Directory Assistance Service

DBR 

Deterministic Bit Rate

DC 

Dedicated Control (SAP)

DCA 

Dynamic Channel Allocation

DCC 

Data Country Code

DCCH 

Dedicated Control Channel

DCH 

Dedicated Channel

DCN 

Data Communication Network

DCOM 

Distributed Component Object Model

DCS 

Digital Cellular System

DDI 

Direct Dialing In

DECT 

Digital Enhanced Cordless Telecommunication

DES 

Destination End Station

DF 

Directory File

DHCP 

Dynamic Host Configuration Protocol

DHO 

Diversity handover

DIR 

This is a field in an RM-cell which indicates the direction of the RM-cell with respect to the data flow with which it is associated.

DIU 

Data Interface Unit

DL 

Downlink

DLA 

Distribution List Application

DMR 

Digital Microwave Radio

DMZ 

Demilitarised Zone

DNIS 

Dialled Number Identification Service

DNS 

Domain Name Server

DNT 

Data Network Terminal

DOCSIS 

Data Over Cable Service Interface Specifikation

DPCCH 

Dedicated Physical Control Channel

DPCH 

Dedicated Physical  Channel

DPDCH 

Dedicated Physical Data Channel

DPTS 

Downlink Pilot Time slot

DRNC 

Drift Radio Network Controller

DRNS 

Drift RNS

DRX 

Discontinuous Reception

DS - 0 

Digital Signal, level 0

DS - 1 

Digital Signal, level 1

DS - 2 

Digital Signal, level 2

DS - 3 

Digital Signal, level 3

DS3 PLCP 

Physical Layer Convergence Protocol

DS-CDMA 

Direct Sequence Code Division Multiple Access

DSCH 

Downlink Shared Channel

DSL 

Digital Subscriber Line

DSLAM 

Digital Subscriber Line Access Mux

DSP 

Digital Signal Processor

DSS2 

Digital Subscriber Signaling System Number 2

DTAP 

Direct Transfer Application Process

DTD 

Data Type Definition

DTE 

Data Terminal Equipment

DTL 

Designated Transit List

DTM 

Dynamic Synchronous Transfer Mode

DTMF 

Dual Tone Multi-Frequency

DTP 

Dynamic Packet Transport

DVB 

Digital Video Broadcasting

DVD 

Digital Versatile Disc

DWDM 

Dense Wavelenght Division Multiplexing

DX 220 

Nokia large-capacity digital exchange for fixed networks

DXC 

Digitcal Cross Connect

DXI 

Data Exchange Interface