Brochure/Catalogue

Topology
The conguration of the network nodes and connections
is called the physical topology. The logical connections
of network nodes possible are referred to as the logical
topology. This states which node pairs can communicate
with one another and whether they have a direct physical
connection. The physical and logical topology does not have
to be identical in networks. As a rule network topologies
can be divided into two classes, where in the rst class
connections from one node to the next one are set up and
in the second class all network nodes are directly connected
to the transmission medium. The most well-known network
topologies are ring topology, bus topology, tree topology and
star topology. There is also meshed topology in long-distance
networks
Transceiver
Transceiver is a compound word made up of transmitter and
receiver and signifying a transmitting/receiving device. The
transceiver implements network access of a station to the
Ethernet and is sometimes called a MAU.
Trunking
The term trunking occurs in Ethernet networks but also
in private exchanges and in mobile communication. In
large Ethernet networks trunking is the parallel switching
of several Ethernet links. The transmission via the parallel
links is used to scale the bandwidth and is activated by the
spanning tree algorithm. As the spanning tree protocol is
unsuitable for granular bandwidth scaling, this technology
has been standardised in the IEE 802.3ad working group
and called “Aggregation of multiple link segments”.
Twisted-Pair Cable
A twisted-pair cable is a symmetrical copper cable
consisting of two wires that are twisted together. The
conductors consist of insulated copper conductors. In
contrast to asymmetrical cables, such as coaxial cables,
symmetrical cables do not have reference potential.
The advantage is that wires can be arranged to prevent
interference between the lines.
VLAN
Virtual networks or virtual LANs (VLAN) are a technological
concept for implementing logical work groups within a
network. This type of network is implemented using LAN-
switching or virtual routing on the link layer or on the
network layer.
VPN
VPN is the abbreviation for Virtual Private Network. These
virtual networks are used to connect local networks together
via public networks such as the Internet. They thus form a
virtual network. There are various VPN technologies. The
most widely distributed are OpenVPN and IPSec.
Web server
A web server is a server programme that provides les via
HTTP protocol. These les are usually websites, pictures and
style sheets. It makes no difference to the web server what
type of les it supplies. Each time a website is requested (for
example by clicking a link), the browser sends an HTTP query
to a web server. This web server can then send the site
requested back. The standard ports for the web server are
84 HTTP protocol and 443 for HTTPS, the encrypted HTTP
(for example with SSL). Usually all page requests are saved
in a log le, from where – by using log le analysis – different
statistics on access can be generated. However these do not
give the full picture, as HTTP is a connectionless protocol.
Glossary
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Technical appendix
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