Axis M1054 User Manual page 59

advantage of UDP is that it is not required to deliver all
data and may drop network packets when there is e.g.
network congestion. This is suitable for live video, as there
is no point in re-transmitting old information that will not
be displayed anyway.
Unicast - Communication between a single sender and a
single receiver over a network. A new connection is
established for each new user.
URL (Uniform Resource Locator) - An "address" on the
network.
Varifocal lens - A varifocal lens provides a wide range of
focal lengths, as opposed to a lens with a fixed focal
length, which only provides one.
VPN (Virtual Private Network) - This creates a secure
"tunnel" between the points within the VPN. Only devices
with the correct "key" will be able to work within the VPN.
The VPN network can be within a company LAN (Local
Area Network), but different sites can also be connected
over the Internet in a secure way. One common use for
VPN is for connecting a remote computer to the corporate
network, via e.g. a direct phone line or via the Internet.
VOP (Video Object Plane) - A VOP is an image frame in an
H.264/MPEG-4 video stream. There are several types of
VOP:
- An I-VOP is complete image frame.
- A P-VOP codes the differences between images, as long
as it is more efficient to do so. Otherwise it codes the whole
image, which may also be a completely new image.
WAN (Wide-Area-Network) - Similar to a LAN, but on a
larger geographical scale.
W-LAN (Wireless LAN) - A wireless LAN is a wireless local
area network that uses radio waves as its carrier: where the
network connections for end-users are wireless. The main
network structure usually uses cables.
Web server - A web server is a program, which allows
web browsers to retrieve files from computers connected to
the Internet. The web server listens for requests from web
browsers and upon receiving a request for a file sends it
back to the browser.
The primary function of a web server is to serve pages to
other remote computers; consequently, it needs to be
installed on a computer that is permanently connected to
the Internet. It also controls access to the server whilst
monitoring and logging server access statistics.
WEP (Wireless Equivalent Privacy) - A wireless security
protocol, specified in the IEEE 802.11 standard, which is
designed to provide a wireless local area network (WLAN)
with a level of security and privacy comparable to that
usually expected of a wired LAN. Security is at two
different levels; 40-bit and 128-bit encryption. The higher
the bit number, the more secure the encryption.
WPA-PSK (Wi-Fi Protected Access - Pre-Shared Key) -
This wireless encryption method uses a pre-shared key
(PSK) for key management. Keys can usually be entered as
manual hex values, as hexadecimal characters, or as a
AXIS M10 Series - Glossary of Terms
Passphrase. WPA-PSK provides a greater degree of security
than WEP.
WPA Enterprise - Instead of a pre-shared key or
passphrase, WPA Enterprise uses 802.1 x RADIUS servers
and an Extensible Authentication Protocol (EAP) for
authentication. The enhanced WPA2 uses Advanced
Encryption Standard (AES) instead of Temporal Key
Integrity Protocol (TKIP) to provide stronger encryption
mechanism. This encryption method provides greater
security, but is difficult to configure and is not
recommended for home users.
Zoom lens - A zoom lens can be moved (zoomed) to
enlarge the view of an object to show more detail.
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