Linksys WRT55AG User Manual page 59

Software - Instructions for the computer. A series of instructions that performs
a particular task is called a "program." The two major categories of software are
"system software" and "application software." System software is made up of
control programs such as the operating system and database management sys-
tem (DBMS). Application software is any program that processes data for the
user.
A common misconception is that software is data. It is not. Software tells the
hardware how to process the data.
Spread Spectrum - Spread Spectrum technology is a wideband radio frequen-
cy technique developed by the military for use in reliable, secure, mission-crit-
ical communications systems. It is designed to trade off bandwidth efficiency
for reliability, integrity, and security. In other words, more bandwidth is con-
sumed than in the case of narrowband transmission, but the trade off produces
a signal that is, in effect, louder and thus easier to detect, provided that the
receiver knows the parameters of the spread-spectrum signal being broadcast.
If a receiver is not tuned to the right frequency, a spread-spectrum signal looks
like background noise. There are two main alternatives, Direct Sequence
Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS).
SSID (Service Set IDentifier) - A unique name shared among all points in a
wireless network. The SSID must be identical for each point in the wireless net-
work and is case-sensitive.
Static IP Address - A permanent IP address that is assigned to a node in an IP
or a TCP/IP network.
Static Routing - Forwarding data in a network via a fixed path. Static routing
cannot adjust to changing line conditions as can dynamic routing.
Storage - The semi-permanent or permanent holding place for digital data.
Subnet Mask - The method used for splitting IP networks into a series of sub-
groups, or subnets. The mask is a binary pattern that is matched up with the IP
address to turn part of the host ID address field into a field for subnets.
Switch - 1. A data switch connects computing devices to host computers,
allowing a large number of devices to share a limited number of ports. 2. A
device for making, breaking, or changing the connections in an electrical cir-
cuit.
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Instant Wireless ® Series Dual-Band Wireless A+G Broadband Router
TCP (Transmission Control Protocol) - A method (protocol) used along with
the IP (Internet Protocol) to send data in the form of message units (datagram)
between network devices over a LAN or WAN. While IP takes care of handling
the actual delivery of the data (routing), TCP takes care of keeping track of the
individual units of data (called packets) that a message is divided into for effi-
cient delivery over the network. TCP is known as a "connection oriented" pro-
tocol due to requiring the receiver of a packet to return an acknowledgment of
receipt to the sender of the packet resulting in transmission control.
TCP/IP (Transmission Control Protocol/Internet Protocol) - The basic com-
munication language or set of protocols for communications over a network
(developed specifically for the Internet). TCP/IP defines a suite or group of
protocols and not only TCP and IP.
Telnet - A terminal emulation protocol commonly used on the Internet and
TCP/IP-based networks. It allows a user at a terminal or computer to log onto
a remote device and run a program.
TFTP (Trivial File Transfer Protocol) - A version of the TCP/IP FTP protocol
that has no directory or password capability.
Throughput - The amount of data moved successfully from one place to
another in a given time period.
UDP (User Datagram Protocol) - A method (protocol) used along with the IP
(Internet Protocol) to send data in the form of message units (datagram)
between network devices over a LAN or WAN. While IP takes care of handling
the actual delivery of the data (routing), UDP takes care of keeping track of the
individual units of data (called packets) that a message is divided into for effi-
cient delivery over the network. UDP is known as a "connection-less" protocol
due to NOT requiring the receiver of a packet to return an acknowledgment of
receipt to the sender of the packet (as opposed to TCP).
Upgrade - To replace existing software or firmware with a newer version.
Upload - To transmit a file over a network. In a communications session,
upload means transmit, download means receive.
URL (Uniform Resource Locator) - The address that defines the route to a file
on the Web or any other Internet facility. URLs are typed into the browser to
access Web pages, and URLs are embedded within the pages themselves to pro-
vide the hypertext links to other pages.
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