User Manual

User’s Guide Glossary
F
filter A device that selectively sorts signals and
passes through a desired range of signals
while suppressing the others. This kind of filter
is used to suppress noise or to separate
signals into bandwidth channels.
firewall A system or combination of systems
that enforces a boundary between two or more
networks.
FLASH A new memory technology, which
combines the nonvolatile features of EPROM’s
with the easy in-system reprogramming of
conventional volatile RAM. See
EPROM.
G
gateway The original Internet term for what is
now called router or more precisely, IP router.
In modern usage, the term “gateway” and
“application gateway” refers to systems, which
perform translation from some native protocol,
or physical data format to another. Examples
include electronic mail gateways, which
translate between X.400 and RFC 822 mail
message formats. See
router.
H
host An (end-user) computer system that
connects to a network, such as a PC,
minicomputer of mainframe.
hotspot A hotspot is wireless public access
system that allows subscribers to connect to a
wireless network in order to access the
Internet or other devices, such as printers.
Hotspots are created by WLAN access points,
installed in public venues. Common locations
for public access are hotels, airport lounges,
railway stations or coffee shops.
HTTPS (Hypertext Transfer Protocol over
Secure Socket Layer, or HTTP over SSL) is a
Web protocol developed by Netscape and built
into its browser that encrypts and decrypts
user page requests as well as the pages that
are returned by the Web server. HTTPS is
really just the use of Netscape's Secure
Socket Layer (SSL) as a sublayer under its
regular HTTP application.
I
ICMP Internet Control Message Protocol. The
TCP/IP protocol used to handle errors and
control messages at the IP layer. ICMP is part
of the IP protocol. Gateways, routers and
hosts use ICMP to send reports of problems
about datagrams back to the original source
that sent the datagram.
interface One of the physical ports on the
router, including the Ethernet and
asynchronous ports.
interface type The type (Ethernet or Point-to-
Point) of one of the interfaces on the router.
internet A collection of networks
interconnected by a set of routers, which allow
them to function as a single, large virtual
network.
Internet (note the capital “I”) The largest
internet in the world consisting of large
national backbone networks (such as MILNET,
NSFNET, and CREN) and a myriad of regional
and local campus networks all over the world.
The Internet is a multiprotocol network, but
generally carries TCP/IP.
Internet address See IP address.
Internet Protocol See IP.
ISP Internet service provider. A company that
provides Internet - related services. Most
importantly, an ISP provides Internet access
services and products to other companies and
consumers.
IP Internet Protocol. The network layer
protocol for the TCP/IP protocol suite. It is a
connectionless, best-effort packet switching
protocol.
IP address A 32-bit address assigned to hosts
using TCP/IP. The address specifies a specific
connection to a network, not the host itself.
See dotted decimal notation.
L
LAN Local Area Network. Any physical
network technology (such as Ethernet) that
operates at high speed (typically 10 Mbit per
second or more) over short distances (up to a
few kilometers). See
WAN.
LED Light Emitting Diode. A luminous
indicator.
Gemtek Systems Page 80