Motorola SURFboard SBG901 - Manual (Page 81)

B
B • Glossary 80
B
Glossary
This glossary defines some of the terms and acronyms used in this document.
TERM DEFINITION
Authentication A process where the CMTS verifies that access is authorized, using a
password, trusted IP address, or serial number.
cable modem A device installed at a subscriber location to provide data
communications over an HFC network. Unless otherwise specified,
all references to “cable modem” in this documentation refer to
DOCSIS cable modems only.
coaxial cable A type of cable consisting of a center wire surrounded by insulation
and a grounded shield of braided (coax) wire. The shield minimizes
electrical and radio frequency interference. Coaxial cable has high
bandwidth and can support transmission over long distances.
DHCP Dynamic Host Configuration Protocol server — dynamically assigns
IP addresses to client hosts on an IP network. DHCP eliminates
manually assigning static IP addresses by “leasing” an IP address
and subnet mask to each client. It enables the automatic reuse of
unused IP addresses.
The SBG901 is simultaneously a DHCP client and a DHCP server.
A DHCP server at the cable system headend assigns a public IP
address to the SBG901 and optionally to clients on the SBG901 LAN.
The SBG901 contains a built-in DHCP server that assigns private IP
addresses to clients.
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.
downstream In a cable data network, this is the direction of the data received by
the computer from the Internet.
firewall A security software system on the SBG901 that enforces an access
control policy between the Internet and the SBG901 LAN.