Linksys BEFSR81 User Manual page 40

Browser - A browser is an application program that provides a way to look at and
interact with all the information on the World Wide Web or PC. The word "brows-
er" seems to have originated prior to the Web as a generic term for user interfaces
that let you browse text files online.
Cable Modem - A device that connects a computer to the cable television net-
work, which in turn connects to the Internet. Once connected, cable modem users
have a continuous connection to the Internet. Cable modems feature asymmetric
transfer rates: around 36 Mbps downstream (from the Internet to the computer),
and from 200 Kbps to 2 Mbps upstream (from the computer to the Internet).
CAT 5 - ANSI/EIA (American National Standards Institute/Electronic Industries
Association) Standard 568 is one of several standards that specify "categories"
(the singular is commonly referred to as "CAT") of twisted pair cabling systems
(wires, junctions, and connectors) in terms of the data rates that they can sustain.
CAT 5 cable has a maximum throughput of 100 Mbps and is usually utilized for
100BaseTX networks.
CPU (Central Processing Unit) - The computing part of the computer. Also
called the "processor," it is made up of the control unit and ALU.
CSMA/CD (Carrier Sense Multiple Access/Collision Detection) - The LAN
access method used in Ethernet. When a device wants to gain access to the net-
work, it checks to see if the network is quiet (senses the carrier). If it is not, it
waits a random amount of time before retrying. If the network is quiet and two
devices access the line at exactly the same time, their signals collide. When the
collision is detected, they both back off and each waits a random amount of time
before retrying.
Database - A database is a collection of data that is organized so that its contents
can easily be accessed, managed, and updated.
Data Packet - One frame in a packet-switched message. Most data communica-
tions is based on dividing the transmitted message into packets. For example, an
Ethernet packet can be from 64 to 1518 bytes in length.
Default Gateway - The routing device used to forward all traffic that is not
addressed to a station within the local subnet.
DHCP (Dynamic Host Configuration Protocol) - A protocol that lets network
administrators centrally manage and automate the assignment of Internet
Protocol (IP) addresses in an organization's network. Using the Internet's set of
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Instant Broadband Series
®
EtherFast Cable/DSL Router with QoS and 8-Port Switch
®
protocol (TCP/IP), each machine that can connect to the Internet needs a unique
IP address. When an organization sets up its computer users with a connection to
the Internet, an IP address must be assigned to each machine. Without DHCP, the
IP address must be entered manually at each computer and, if computers move to
another location in another part of the network, a new IP address must be entered.
DHCP lets a network administrator supervise and distribute IP addresses from a
central point and automatically sends a new IP address when a computer is
plugged into a different place in the network.
DHCP uses the concept of a "lease" or amount of time that a given IP address
will be valid for a computer. The lease time can vary depending on how long a
user is likely to require the Internet connection at a particular location. It's espe-
cially useful in education and other environments where users change frequently.
Using very short leases, DHCP can dynamically reconfigure networks in which
there are more computers than there are available IP addresses.
DHCP supports static addresses for computers containing Web servers that need
a permanent IP address.
DMZ - (DeMilitarized Zone) allows one IP address (or computer) to be exposed
to the Internet. Some applications require multiple TCP/IP ports to be open. It
is recommended that you set your computer with a static IP address if you want
to use DMZ Hosting.
DNS - The Domain Name System (DNS) is the way that Internet domain names
are located and translated into Internet Protocol (IP) addresses. A domain name
is a meaningful and easy-to-remember "handle" for an Internet address.
Domain - A subnetwork comprised of a group of clients and servers under the
control of one security database. Dividing LANs into domains improves per-
formance and security.
Download - To receive a file transmitted over a network. In a communications
session, download means receive, and upload means transmit.
Driver - A workstation or server software module that provides an interface
between a network interface card and the upper-layer protocol software running
in the computer; it is designed for a specific NIC, and is installed during the ini-
tial installation of a network-compatible client or server operating system.
Dynamic IP Address - An IP address that is automatically assigned to a client
station in a TCP/IP network, typically by a DHCP server. Network devices that
serve multiple users, such as servers and printers, are usually assigned static IP
addresses.
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