ZyXEL Communications Prestige 964 User Manual page 46

Prestige 944S Cable Sharing Gateway with 4-port Switch
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.
Central distribution point for a CATV system. Video signals are received here from satellites and
Headend
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 (hybrid fiber coaxial cable) is a telecommunication technology in which fiber optic cable
HFC
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
H Glossary