Motorola SURFBOARD SVG2500 - Manual (Page 156)

17 GLOSSARY
141
TERM DEFINITION
default route The route by which packets are forwarded when other routes in
the routing table do not apply.
dB decibel
dBc Signal level expressed in dB relative to the unmodulated carrier
level desired.
DBm A unit of measurement referenced to one milliwatt across
specified impedance. 0dBm = 1 milliwatt across 75 ohms.
dBmV Signal level expressed in dB as the ratio of the signal power in a
75-ohm system to a reference power when 1 mV is across 75
ohms.
demodulation An operation to restore a previously modulated wave and
separate the multiple signals that were combined and
modulated on a sub carrier.
DHCP A Dynamic Host Configuration Protocol server dynamically
assigns IP addresses to client hosts on an IP network. DHCP
eliminates the need to manually assign static IP addresses
by “leasing” an IP address and subnet mask to each client. It
enables the automatic reuse of unused IP addresses.
The SVG2500 is simultaneously a DHCP client and a DHCP
server.
A DHCP server at the cable system headend assigns a public IP
address to the SVG2500 and optionally to clients on the
SVG2500 LAN.
The SVG2500 contains a built-in DHCP server that assigns
private IP addresses to clients.
distortion An undesired change in signal waveform within a transmission
medium. A nonlinear reproduction of the input waveform.
DMZ A “de-militarized zone” is one or more hosts logically located
between a private LAN and the Internet. A DMZ prevents direct
access by outside users to private data. (The term comes from
the geographic buffers located between some conflicting
countries, such as North and South Korea.) In a typical small
DMZ configuration, the DMZ host receives requests from private
LAN users to access external web sites and initiates sessions for
these requests. The DMZ host cannot initiate a session back to
the private LAN. Internet users outside the private LAN can
access only the DMZ host. You can use a DMZ to set up a web
server or for gaming without exposing confidential data.