User Manual

UM DS-90xxHUHI-F8/N User Manual 041717NA 161
22. Appendix
22.1. Glossary
• Dual-Stream. 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 1080p and the sub-stream having a maximum resolution of CIF.
• DVR (Digital Video Recorder). A device that is able to accept video signals from analog cameras,
compress the signal and store it on its hard drives.
• HDD (Hard Disk Drive). A storage medium that stores digitally encoded data on platters with magnetic
surfaces.
• DHCP (Dynamic Host Configuration Protocol). A network application protocol used by devices (DHCP
clients) to obtain configuration information for operation in an Internet Protocol network.
• HTTP (Hypertext Transfer Protocol). A protocol to transfer hypertext request and information between
servers and browsers over a network
• PPPoE (Point-to-Point Protocol over Ethernet). 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 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 NVR.
• NTP (Network Time Protocol). A protocol designed to synchronize computer clocks over a network.
• NTSC (National Television System Committee). 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 60 Hz.
• NVR (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.
• PAL (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 50 Hz.
• PTZ (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.
• USB (Universal Serial Bus). A plug-and-play serial bus standard to interface devices to a host
computer.