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18.
Important Notes
18.1 Glossary
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Dual-Stream:
Dual-stream is a technology used to record a 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 1080P and the
sub-stream having a maximum resolution of CIF.
•
DVR:
Acronym for Digital Video Recorder. A DVR is a device that is able to accept video
signals from analog cameras, compress the signal and store it on its hard drives.
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HDD:
Acronym for Hard Disk Drive. A storage medium which stores digitally encoded data on
platters with magnetic surfaces.
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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.
•
HTTP:
Acronym for Hypertext Transfer Protocol - a protocol to transfer hypertext requests
and information between servers and browsers over a network.
•
PPPoE:
PPPoE or 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.
•
DDNS:
Dynamic DNS is a method, protocol or network service that provides the capability
for a networked device, such as a router or a 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.
•
Hybrid DVR:
A hybrid DVR is a combination of a DVR and a NVR.
•
NTP:
Acronym for Network Time Protocol. A protocol designed to synchronize the clocks of
computers over a network.
•
NTSC:
Acronym for the 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.
•
NVR:
Acronym for a Network Video Recorder. An NVR can be a PC-based or embedded
system used for centralized management and storage for IP cameras, IP Domes and other
DVRs.
