DA
Distribution Amplifier that splits a single input to produce several buffered outputs, enabling signals to be routed to many destinations without signal degradation.

Data Compression
A process that reduces the amount of data needed to store or send a video or audio signal.

DES
Data Encryption Standard.

Desktop videoconferencing
Videoconferencing on a personal computer. Most appropriate for small groups or individuals (compare with room-based videoconferencing). Many desktop videoconferencing systems support document sharing.

DHCP
A protocol used to dynamically assign IP configuration information, such as an IP address, to hosts

Diffserv
Differentiated Services

DNS
Domain Name System. The basic name-to-address translation mechanism used in the IP environment. used to translate between human friendly names such as www.ja.net, and the numeric IP addresses that computers themselves use to communicate. DNS information can also be used to direct the operation of some Internet services, notably electronic mail.

Document sharing
A feature supported by many desktop videoconferencing systems that allows participants at both ends of a videoconference to view and edit the same computer document.

Domain
An administrative authority controlling the issue and registration of unique network names and addresses. A domain limits the scope of meaning of a name. Some examples of domains are edu, earn, bitnet, de (Germany), nl (Netherlands).