User's Manual Fixed Dome Network Camera AXIS 225FD

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AXIS 225FD - Glossary of Terms
Pre/post alarm image - The images from immediately
before and after an alarm.
Privacy mask - An ima
ge or specified area used to block
out certain parts of the video image.
Protocol
- A special set of rules governing how two
entities will communicate. Protocols are found at many
levels of communication, and there are hardware
protocols and software protocols.
Router - A d
evice that determines the next network point
to which a packet should be forwarded on its way to its
final destination. A router is often included as part of a
network switch (see below).
RTP- Real-
Time Transfer Protocol. A transfer protocol
designed for delivery of live contents, e.g. MPEG-4.
Simplex -
In simplex operation, a network cable or
communications channel can send information in one
direction only.
SMTP -
A common e-mail protocol.
SNMP - Simple Netwo
rk Management Protocol. An
application layer protocol that facilitates the exchange of
management information between network devices. It is
part of the Transmission Control Protocol/Internet
Protocol (TCP/IP) protocol suite.
Subnet Mask -
An IP address consists of two
components: the network address and the host address.
“Subnetting’ enables a network administrator to further
divide the host part of the address into two or more
subnets. The subnet mask identifies the subnet to which
an IP address belongs.
Switch - Whilst a s
imple hub transmits all data to all
devices connected to it, a switch only transmits the data
to the device it is specifically intended for.
TCP/IP -
Transmission Control Protocol/Internet Protocol.
A suite of network protocols that determine how data is
transmitted. TCP/IP is used on many networks, including
the Internet. TCP keeps track of the individual packets of
information and IP contains the rules for how the packets
are actually sent and received.
UDP -
The User Datagram Protocol is a communications
protocol that offers a limited amount of service when
messages are exchanged between computers in a network
that uses the Internet Protocol (IP). UDP is an alternative
to the Transmission Control Protocol (TCP) and, together
with IP, is also known as UDP/IP.
Unicast - Comm
unication that takes place over a network
between a single sender and a single receiver.
UPnP
TM
- Allows the automatic peer-to-peer detection of
devices on the network.
URL - Un
iform Resource Locator. An “address" on the
network.
Varifocal - A
varifocal lens provides a wide range of
focal lengths, as opposed to a lens with a fixed focal
length, which only provides one.
WAN - Wide-
Area-Network. Similar to a LAN, but on a
larger geographical scale.
Web server - A progra
m on a computer (server) providing
the resources (e.g. web pages) requested by the user
(client).