AirLive POE-100CAMv2 - Manual (Page 130)

AirLive POE100CAMv2 User’s Manual
129
Factory default settings -
These are the settings that originally applied for a device when it was first delivered from the factory. If it
should become necessary to reset a device to its factory default settings, this will, for many devices,
completely reset any settings that were changed by the user.
Firewall -
A firewall works as a barrier between networks, for example, between a Local Area Network and the
Internet. The firewall ensures that only authorized users are allowed to access the one network from the
other. A firewall can be software running on a computer, or it can be a standalone hardware device.
Focal length -
Measured in millimeters, the focal length of a camera lens determines the width of the horizontal field of
view, which in turn is measured in degrees.
FTP (File Transfer Protocol) -
An application protocol that uses the TCP/IP protocols. It is used to exchange files between
computers/devices on networks.
Frame -
A frame is a complete video image. In the 2:1 interlaced scanning format of the RS-170 and CCIR
formats, a frame is made up of two separate fields of 262.5 or 312.5 lines interlaced at 60 or 50 Hz to
form a complete frame, which appears at 30 or 25 Hz. In video cameras with a progressive scan, each
frame is scanned line-by-line and not interlaced; most are also displayed at 30 and 25 Hz.
Frame rate -
The frame rate used to describe the frequency at which a video stream is updated is measured in
frames per second (fps). A higher frame rate is advantageous when there is movement in the video
stream, as it maintains image quality throughout.
Full-duplex -
Transmission of data in two directions simultaneously. In an audio system this would describe for
example, a telephone systems. Half-duplex also provides bi-directional communication, but only in one
direction at a time, as in a walkie-talkie system. See also Simplex.
Gain -
Gain is the amplification factor and the extent to which an analog amplifier boosts the strength of a signal.
Amplification factors are usually expressed in terms of power. Decibel (dB) is the most common way of
quantifying the gain of an amplifier.
Gateway -
A gateway is a point in a network that acts as an entry point to another network. In a corporate network
for example, a computer server acting as a gateway often also acts as a proxy server and a firewall
server. A gateway is often associated with both a router, which knows where to direct a given packet of