Dual-Band Wireless A/G Broadband Router
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Fast Ethernet
- A 100 Mbps technology based on the 10Base-T Ethernet
CSMA/CD network access method.
FHSS
(
F
requency
H
opping
S
pread
S
pectrum) - FHSS continuously changes
(hops) the carrier frequency of a conventional carrier several times per second
according to a pseudo-random set of channels. Because a fixed frequency is not
used, and only the transmitter and receiver know the hop patterns, interception
of FHSS is extremely difficult.
Firewall
- A firewall is a set of related programs, located at a network gateway
server, that protects the resources of a network from users from other networks.
(The term also implies the security policy that is used with the programs.) An
enterprise with an intranet that allows its workers access to the wider Internet
installs a firewall to prevent outsiders from accessing its own private data
resources and for controlling what outside resources to which its own users
have access.
Basically, a firewall, working closely with a router, examines each network
packet to determine whether to forward it toward its destination.
Firmware
- Code that is written onto read-only memory (ROM) or program-
mable read-only memory (PROM). Once firmware has been written onto the
ROM or PROM, it is retained even when the device is turned off.
Fragmentation
- Breaking a packet into smaller units when transmitting over
a network medium that cannot support the original size of the packet.
FTP
(
F
ile
T
ransfer
P
rotocol) - A protocol used to transfer files over a TCP/IP
network (Internet, UNIX, etc.). For example, after developing the HTML pages
for a website on a local machine, they are typically uploaded to the Web serv-
er using FTP.
FTP includes functions to log onto the network, list directories, and copy files.
It can also convert between the ASCII and EBCDIC character codes. FTP oper-
ations can be performed by typing commands at a command prompt or via an
FTP utility running under a graphical interface such as Windows. FTP transfers
can also be initiated from within a Web browser by entering the URL preceded
with ftp://.
Unlike e-mail programs in which graphics and program files have to be
“attached,” FTP is designed to handle binary files directly and does not add the
overhead of encoding and decoding the data.
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Full Duplex
- The ability of a device or line to transmit data simultaneously in
both directions.
Gateway
– A device that interconnects networks with different, incompatible
communications protocols.
Half Duplex
- Data transmission that can occur in two directions over a single
line, but only one direction at a time.
Hardware
- Hardware is the physical aspect of computers, telecommunica-
tions, and other information technology devices. The term arose as a way to dis-
tinguish the “box” and the electronic circuitry and components of a computer
from the program you put in it to make it do things. The program came to be
known as the software.
Hub
- The device that serves as the central location for attaching wires from
workstations. Can be passive, where there is no amplification of the signals; or
active, where the hubs are used like repeaters to provide an extension of the
cable that connects to a workstation.
HTTP
(
H
yper
T
ext
T
ransport
P
rotocol) - The communications protocol used
to connect to servers on the World Wide Web. Its primary function is to estab-
lish a connection with a Web server and transmit HTML pages to the client
browser.
IEEE
- The Institute of Electrical and Electronics Engineers. The IEEE
describes itself as “the world's largest technical professional society—promot-
ing the development and application of electrotechnology and allied sciences
for the benefit of humanity, the advancement of the profession, and the well-
being of our members.”
The IEEE fosters the development of standards that often become national and
international standards. The organization publishes a number of journals, has
many local chapters, and has several large societies in special areas, such as the
IEEE Computer Society.
Infrastructure Network
- An infrastructure network is a group of computers
or other devices, each with a wireless adapter, connected as an 802.11 wireless
LAN. In infrastructure mode, the wireless devices communicate with each
other and to a wired network by first going through an access point. An infra-
structure wireless network connected to a wired network is referred to as a
Basic Service Set (BSS). A set of two or more BSS in a single network is
referred to as an Extended Service Set (ESS). Infrastructure mode is useful at
