User guide

Glossary
125
Firewall
A combination of techniques used to protect one network from unknown
networks and users on the outside. Firewalls can filter or block traffic and act
as a management and network security point where all traffic can be
scrutinized.
GUI
Graphical User Interface. It allows to communicate with the computer
through pull-down menus and icons.
Hop Count
Represents the number of routers in a network through which the data packet
has to pass to get to its destination.
In-band Signaling
Transmission within the frequency range used for data transmission; i.e.,
results in use of bandwidth normally reserved for data.
IP address
Internet Address. A 32-bit address assigned to devices that participate in a
network using TCP/IP. An IP address consists of four octets separated with
periods defining network, optional subnetwork, and host sections.
IPX (Internet Packet Exchange)
A network layer protocol developed by Novell and used in NetWare and other
networks.
ISDN
Integrated Services Digital Network. Digital transmission standard defining
communication protocols permitting telephone networks to carry data, voice,
fax, and other streams.
Leased Line
A telecommunications line between two service points leased from a
communications carrier for private use, usually incurring a monthly service
rate.
LEDs (Light Emitting Diodes)
Type of indicator lights on the panel of the router.
Local Area Network (LAN)
A network connecting computers over a relatively small geographic area
(usually within a single campus or building).