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MAC address
The MAC address (Media Access Control Address) is the hardware address of each network adapt-
er. It it used to identify devices within a LAN. The MAC addresses are already assigned unique by the
manufacturer. They cannot be changed by the user normally.
Mbit/s (Megabit per
second)
Measuring unit for the bit rate, this means the speed with that the bits are forwarded to a certain
position. Usually the speed of networks is specified in Mbit. LANs are operated mostly with 10 or 100
Mbit/s. See also bit rate.
net mask (subnet and
subnet mask)
A subnet is a separated part of an organisation's network that can be identified. A subnet mostly
represents all computer of one geographical location in one building or in the same LAN. By subdi-
viding one network into subnets, each subnet can be connected to the internet via the same, shared
network address. The subnet is part of an IP address. Based on the subnet mask the network router
can split the IP address into network and host part. Based on the network part a router can decide, if
an IP package is determined for a specific subnet or not.
Network
To connect end devices such as computers, that are connected together via different lines and have
shared access to data and devices (printer, network cameras).
NTP
The Network Time Protocol (NTP) is a standard for the synchronisation of clocks within computer
systems via packet-based communication networks. NTP is using the wireless transport protocol
UDP. NTP has been especially developed to implement a reliable time specification via network with
variable packet runtime.
Pixel
One of the amount of tiny screen dots a digital image consists of. By its colour and intensity a pixel
determines a tiny part of the entire image.
PoE (Power over Ether-
net)
By using PoE a network device can be supplied via the same cable that is used for the network con-
nection. This is an advantage in case of IP or remote monitoring, if it is too expensive to run a cable
from the next power socket.
POP3
The Post Office Protocol (POP) is a transmission protocol. Using this protocol a client can fetch E-
Mails from the E-Mail server. ... POP3 is an ASCII protocol. The control of the data transmission is
based on commands that are send to the port 110 by default. ... permits only the listing, fetching and
deleting of E-Mails at the E-Mail server.
Port
Services, that are running on an IP device are distinguished by their port number and their transport
protocol (TCP or UDP). Within a TCP or UDP packet the port numbers have to be specified always.
For some services standard port numbers have established. These are inserted automatically (e.g.
port 80 for http) by the client programs. The user itself comes into contact with it only in exceptional
circumstances.
PTZ camera
Abbreviation for pan/tilt/zoom. The ability of a camera to move left, right, up and down as well as the
ability to zoom into an image.
Router
If the communication of two IP devices within an IP network includes several networks (see subnet),
then it is called routing. A router is to be used. The device determines on which way a packet is for-
warded as fast as possible to the target client. In case of devices for the end user, mostly the router
is combined with a network switch in one device.
RSS feeds
RSS feeds (Rich Site Summary, as of version 2.0 Really Simple Syndication Feed) are used to dis-
seminate information quick and easy via internet. If an user has subscribed a RSS channel, the client
is searching for updates in the RSS feed periodically.
SD card
SD Memory Card (Secure Digital Memory Card). The SD card is a digital storage which is based on
flash memory modules.
Server
In general the server is a computer program, which provides services for other programs on the
same or another computer. A computer on which a service program is running, is also called a
server. In practice the server can run many server and client programs. The computer program
which provides the requested HTML sites or files for the client (browser) is called a web server.
SIP (Session Initiation
Protocol)
The Session Initiation Protocol is a network protocol to establish, control and terminate a communi-
cation connection via computer network. SIP is an often used protocol in the IP telephony.
