5400C Series DVR User Manual
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14 APPENDIX
14.1. Glossary
1.
Dual Stream:
Dual stream is a technology used to record high resolution video locally
while transmitting a lower resolution stream over the network. The two streams are
generated by the DVR, with the main stream having a maximum resolution of 4CIF and the
sub-stream having a maximum resolution of CIF.
2.
DVR:
Acronym for Digital Video Recorder. A DVR is device that is able to accept video
signals from analog cameras, compress the signal and store it on its hard drives.
3.
HDD:
Acronym for Hard Disk Drive. A storage medium which stores digitally encoded data
on platters with magnetic surfaces.
4.
DHCP:
Dynamic Host Configuration Protocol (DHCP) is a network application protocol
used by devices (DHCP clients) to obtain configuration information for operation in an
Internet Protocol network.
5.
HTTP:
Acronym for Hypertext Transfer Protocol. A protocol to transfer hypertext request
and information between servers and browsers over a network
6.
DHCP:
PPPoE, Point-to-Point Protocol over Ethernet, is a network protocol for
encapsulating Point-to-Point Protocol (PPP) frames inside Ethernet frames. It is used
mainly with ADSL services where individual users connect to the ADSL transceiver
(modem) over Ethernet and in plain Metro Ethernet networks.
7.
DDNS:
Dynamic DNS is a method, protocol, or network service that provides the capability
for a networked device, such as a router or computer system using the Internet Protocol
Suite, to notify a domain name server to change, in real time (ad-hoc) the active DNS
configuration of its configured hostnames, addresses or other information stored in DNS.
8.
NTP:
Acronym for Network Time Protocol. A protocol designed to synchronize the clocks
of computers over a network.
9.
NTSC:
Acronym for National Television System Committee. NTSC is an analog television
standard used in such countries as the United States and Japan. Each frame of an NTSC
signal contains 525 scan lines at 60Hz.
10.
PAL:
Acronym for Phase Alternating Line. PAL is also another video standard used in
broadcast televisions systems in large parts of the world. PAL signal contains 625 scan
lines at 50Hz.
11.
PTZ:
Acronym for Pan, Tilt, Zoom. PTZ cameras are motor driven systems that allow the
camera to pan left and right, tilt up and down and zoom in and out.
