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Appendices
Corinex ADSL2+ Wireless Gateway G
depending on how long a user is likely to require the Internet connection at a
particular location. It’s especially useful in education and other environments where
users change frequently. Using very short leases, DHCP can dynamically recon-
figure networks in which there are more computers than there are available IP
addresses. DHCP supports static addresses for computers containing Web servers
that need a permanent IP address.
DMZ - (DeMilitarized Zone) allows one IP address (or computer) to be exposed
to the Internet. Some applications require multiple TCP/IP ports to be open. It is
recommended that you set your computer with a static IP address if you want to
use DMZ Hosting.
DNS - Domain Name System (DNS). The distributed name/address mechanism
used in the Internet.
Domain - A subnetwork comprised of a group of clients and servers under
the control of one security database. Dividing LANs into domains improves
performance and security.
Download - To receive a file transmitted over a network. In a communications
session, download means receive, and upload means transmit.
DSL - (Digital Subscriber Line) - An always-on broadband connection over
traditional phone lines.
Driver - A workstation or server software module that provides an interface
between a network interface card and the upper-layer protocol software running
in the computer; it is designed for a specific NIC, and is installed during the initial
installation of a network-compatible client or server operating system.
DSSS (Direct-Sequence Spread-Spectrum) - DSSS generates a redundant bit
pattern for each bit to be transmitted. This bit pattern is called a chip (or chipping
code). The longer the chip, the greater the probability that the original data can be
recovered. Even if one or more bits in the chip are damaged during transmission,
statistical techniques embedded in the radio can recover the original data without
the need for retransmission. To an unintended receiver, DSSS appears as low power
wideband noise and is rejected (ignored) by most narrowband receivers.
DTIM - (Delivery Traffic Indication Message) - A message included in data packets
that can increase wireless efficiency.