User manual

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Appendix I: Glossary of Terms
ActiveX - A control (or set of rules) used by a browser. ActiveX controls are often downloaded
and installed automatically as required.
ARP - Address Resolution Protocol. A method for finding a host's Ethernet address from its
Internet address. The sender broadcasts an ARP packet containing the Internet address of
another host and waits for it (or some other host) to send back its Ethernet address. Each host
maintains a cache of address translations to reduce delay and loading. ARP allows the Internet
address to be independent of the Ethernet address, but it only works if all hosts support it. The
ARP command can be used to set the IP addresses for your product.
CGI - Common Gateway Interface. A standard for running external programs from a World Wide
Web HTTP server. CGI specifies how to pass arguments to the executing program as part of the
HTTP request. It also defines a set of environment variables. Commonly, the program will
generate some HTML that will be passed back to the browser, but it can also request URL
redirection. Basically, it’s a set of rules (or a program) that allows a Web server to communicate
with other programs.
DSL - Digital Subscriber Loop. A family of digital telecommunications protocols designed to
allow high-speed data communication over the existing copper telephone lines between end-
users and telephone companies.
DHCP - A protocol that provides a means to dynamically allocate IP addresses to computers on
a local area network. The system administrator assigns a range of IP addresses to a DHCP, and
each client computer on the LAN has its TCP/IP software configured to request an IP address
from the DHCP server. The request and grant process uses a lease concept with a controllable
time period.
Ethernet - A widely used networking standard.
Firewall - A virtual barrier between a LAN (Local Area Network) and other networks; e.g., the
Internet.
Frame Grabber Card - Plug-in hardware for "grabbing" images.
FTP - A client-server protocol that allows a user on one computer to transfer files to and from
another computer over a TCP/IP network. Also, the client program the user executes to transfer
files. It is defined in STD 9, RFC 959.
HTML - A markup language used to structure text and multimedia documents and to set up
hypertext links between documents, used extensively on the World Wide Web.
HTTP - A protocol used to request and transmit files, especially Web pages.
Intranet - A privately maintained computer network that can be accessed only by authorized
persons, especially members or employees of the organization that owns it.
IP - Internet Protocol. The network layer for the TCP/IP protocol suite widely used on Ethernet
networks, defined in STD 5, RFC 791. IP is a connectionless, best-effort packet switching
protocol. It provides packet routing, fragmentation and re-assembly through the data link layer.
IP number (address) - A unique number used by a computer on the network to allow it to be
identified and found.