AirLive POE-100CAMv2 - Manual (Page 129)

AirLive POE100CAMv2 User’s Manual
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transmission. The codec also converts received digital signals back into analog format. A codec uses
analog-to-digital conversion and digital-to-analog conversion in the same chip.
Codec can also mean compression/decompression, in which case it is generally taken to mean an
algorithm or computer program for reducing the size of large files and programs.
Compression -
See Image Compression.
Contrast -
Defines the degree of difference between the lightest and darkest parts of an image or video stream.
DC-Iris -
This special type of iris is electrically controlled by the camera, to automatically regulate the amount of
light allowed to enter.
DHCP (Dynamic Host Configuration Protocol) -
DHCP is a protocol that lets network administrators automate and centrally manage the assignment of
Internet Protocol (IP) addresses to network devices in a network.
DHCP uses the concept of a "lease" or amount of time that a given IP address will be valid for a
computer. The lease time can vary, depending on how long a user is likely to require the network
connection at a particular location.
DHCP also supports static addresses for example, computers running web servers, which need a
permanent IP address.
DNS (Domain Name System) -
DNS is used to locate and translate Internet domain names into IP (Internet Protocol) addresses. A
domain name is a meaningful and easy-to-remember name for an Internet address. For example the
domain name www.example.com is much easier to remember than 192.0.34.166. The translation tables
for domain names are contained in Domain name servers.
Domain Server -
Domains can also be used by organizations who wish to centralize the management of their (Windows)
computers. Each user within a domain has an account that usually allows them to log in to and use any
computer in the domain, although restrictions may also apply. The domain server is the server that
authenticates the users on the network.
Duplex -
See Full-duplex.
Ethernet -
Ethernet is the most widely installed local area network technology. An Ethernet LAN typically uses
special grades of twisted pair wires. The most commonly installed Ethernet systems are 10BASE-T and
100BASE-T10, which provide transmission speeds up to 10 Mbps and 100 Mbps respectively.