Appendices
IP Video Door Station DS06M(P) Operation User Manual
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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.
FTP (File Transfer Protocol)
is an application protocol that uses the TCP/IP protocols,
used to exchange files between computers/devices on networks.
Full-duplex
means transmission of data in two directions simultaneously. In an audio
system this would describe e.g. a telephone system. Half-duplex also provides bi-directional
communication, but only in one direction at a time, as in a walkie-talkie system.
G.711
is the default pulse code modulation (PCM) standard for Internet Protocol (IP) private
branch exchange (PBX) vendors, as well as for the public switched telephone network (PSTN).
G.711 digitizes analog voice signals producing output at 64 kilobits per second (Kbps).
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. The decibel (dB)
is the most common way of quantifying the gain of an amplifier.
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 data that arrives at the gateway, and a switch, which furnishes the actual
path in and out of the gateway for a given packet.
HTTP (Hypertext Transfer Protocol)
is the set of rules for exchanging files (text, graphic
images, sound, video, and other multimedia files) on the web. The HTTP protocol runs on top of
the TCP/IP suite of protocols.
HTTPS (Hypertext Transfer Protocol over SSL)
is a web protocol used by browsers and
web servers to encrypt and decrypt user page requests and the pages returned by the server. The
encrypted exchange of information is governed by the use of an HTTPS certificate (issued by a
Certificate Authority), which guarantees the authenticity of the server.
Hub
is used to connect multiple devices to the network. The hub transmits all data to all
devices connected to it, whereas a switch will only transmit the data to the device it is specifically
intended for.
ICMP
is a network protocol useful in Internet Protocol (IP) network management and
administration. ICMP is a required element of IP implementations. ICMP is a control protocol,
meaning that it does not carry application data, but rather information about the status of the
network itself.
