Auerswald COMpact 4000 Operation Manual page 762

Glossary
Terminology
D
When you dial an emergency number, the phone number transmitted will
always be the number assigned by the network provider, not the customer-
defined phone number.
Codec
A codec is a method that encodes (digitises) analogue voice data for transmission and again
decodes again, meaning converts into back into voice. There are various codecs that feature
different voice data compression rates thereby require different band widths for data trans-
mission. The equality of VoIP calls is dependent on the codec used.
D
DDI
The DDI (Direct Dial In) is the extension number for dialling directly to a specific subscriber on
a telephone system. Example: In the number 0 53 06 / 92 00 - 700, 700 is the Direct Dial In
number (DDI) for the Auerswald info-line.
DHCP
DHCP (Dynamic Host Configuration Protocol) is a client/server protocol for dynamically
allocating IP addresses and network parameters. The IP addresses are requested by the
DHCP clients (PCs in the network) on the DHCP server (for example, a router or the Internet
service provider). The DHCP server takes these IP addresses from a set address pool and
sends them to the client. In addition, the client receives additional information (for example, the
addresses for the standard gateway and DNS server).
The IP address is temporarily allocated for a certain amount of time. If the address is no longer
required by the client, the server has access to it again and can allocate it to another client.
DiffServ
The Differentiated Services Flag (DiffServ) is evaluated by active network components such as
routers or switches in networks in order to forward packets according to their priority. This is
necessary, for example, to give voice packets (VoIP) priority and to achieve better voice quality.
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COMpact 4000 - Firmware V6.6A - Installation, Operation and Configuration V03 03/2016