P964 APR
Cable Router with 802.11g Access Point
Glossary
G
FCC
The FCC (Federal Communications Commission) is in charge of allocating the electromagnetic
spectrum and thus the bandwidth of various communication systems.
Firewall
A hardware or software "wall" that restricts access in and out of a network. Firewalls are most
often used to separate an internal LAN or WAN from the Internet.
Flash memory
The nonvolatile storage that can be electrically erased and reprogrammed so that data can be
stored, booted, and rewritten as necessary.
FTP
File Transfer Protocol is an Internet file transfer service that operates on the Internet and over
TCP/IP networks. FTP is basically a client/server protocol in which a system running the FTP
server accepts commands from a system running an FTP client. The service allows users to send
commands to the server for uploading and downloading files. FTP is popular on the Internet
because it allows for speedy transfer of large files between two systems.
Gateway
A gateway is a computer system or other device that acts as a translator between two systems that
do not use the same communication protocols, data formatting structures, languages, and/or
architecture.
Hacker
Generally, a hacker is anyone who enjoys experimenting with technology including computers
and networks. Not all hackers are criminals breaking into systems. Some are legitimate users and
hobbyists. Nevertheless, some are dedicated criminals or vandals.
HDLC
HDLC (High-level Data Link Control) is a bit-oriented (the data is monitored bit by bit), link
layer protocol for the transmission of data over synchronous networks.
Headend
Central distribution point for a CATV system. Video signals are received here from satellites and
maybe other sources, frequency converted to the appropriate channels combined with locally
originated signals and rebroadcast onto the HFC plant. The headend is where the CMTS is
normally located.
HFC
HFC (hybrid fiber coaxial cable) is a telecommunication technology in which fiber optic cable
and coaxial cable are used in different portions of a network to carry broadband content (such as
video, data and voice). Typically, a local cable TV company might use fiber optic cable from the
cable headend (distribution center) to serving nodes located close to business and residential
users and from these nodes use coaxial cable to individual businesses and homes. An advantage
of HFC is that some of the characteristics of fiber optic cable (high bandwidth and low noise and
interference susceptibility) can be brought close to the user without having to replace the existing
coaxial cable that is installed all the way to the home and business.
Host
Any computer on a network that is a repository for services available to other computers on the
network. It is quite common to have one host machine provide several services, such as WWW
and USENET.
HTTP
Hyper Text Transfer Protocol. The most common protocol used on the Internet. HTTP is the
primary protocol used for web sites and web browsers. It is also prone to certain kinds of attacks.
IANA
Internet Assigned Number Authority acts as the clearinghouse to assign and coordinate the use of
numerous Internet protocol parameters such as Internet addresses, domain names, protocol
numbers, and more. The IANA Web site is at http://www.isi.edu/iana.
ICMP
Internet Control Message Protocol is a message control and error-reporting protocol between a
host server and a gateway to the Internet. ICMP uses Internet Protocol (IP) datagrams, but the
messages are processed by the TCP/IP software and are not directly apparent to the application
user.
Integrity
Proof that the data is the same as originally intended. Unauthorized software or people have not
altered the original information.
internet
(Lower case i) Any time you connect 2 or more networks together, you have an internet.
Internet
(Upper case I) The vast collection of inter-connected networks that all use the TCP/IP protocols
and that evolved from the ARPANET of the late 60’s and early 70’s. The Internet now (July
1995) connects roughly 60,000 independent networks into a vast global internet
Internet Worm
See Worm.
Intranet
A private network inside a company or organization that uses the same kinds of software that you
would find on the public Internet, but that is only for internal use.
Intruder
Person or software interested in breaking computer security to access, modify, or damage data.
Also see Cracker.
IP
Internet Protocol, is the underlying protocol for routing packets on the Internet and other
TCP/IP-based networks.
IPCP (PPP)
IP Control Protocol allows changes to IP parameters such as the IP address.
IPX
Internetwork Packet eXchange The native NetWare internetworking protocol is IPX
(Internetwork Packet Exchange). Like IP (Internet Protocol), IPX is an internetworking protocol
that provides datagram services.
