Brochure/Catalogue

Port Mirroring
Port mirroring means that the data trafc of a switch port
can be mirrored, in order to detect errors or to measure
throughput, onto another port to which a management
station can be connected.
PPPoE
The PPoE (Point to Point Protocol over Ethernet) was
developed in order to connect components and LANs to
the Internet. It takes advantage of the divided Ethernet
environment together with the trusted and secure dial-up
access user model from PPP. It allows individual PCs
to establish PPP sections to various target networks
simultaneously. A LAN and multiple components can also
establish multiple simultaneous PPP sessions for connection
to various target networks.
Promiscuous Mode
The Promiscuous Mode is a particular receiver mode for
network equipment. In this mode the device reads all the
incoming data trafc sent to the network interface that has
been switched to this mode and transmits the data to be
processed to the operating system. Normally this device
would only process packets directed to itself, which is done
for example in Ethernet networks by evaluating the MAC
address.
Propagation Delay
The delay is the time that the signal requires to go from one
point in a transmission channel to another. Depending on
the transmission medium, the delay is the speed of light, as
in satellite transmission, or less when transmitting in data
cables and FO cables. It does not depend on the speed of
light, but depends mostly on the dielectric constant of the
medium or in FO cables on the refraction.
Protocol
A data transmission protocol establishes the rules for the
exchange of information in the form of a directory. This
includes all formats, parameters and specications for
a complete, perfect and effective transmission of data.
Protocols include conventions on data formats, times and
how errors are treated when exchanging data between
computers. A protocol is a convention on setting up
connections, monitoring connections and terminating
connections. Different protocols are necessary in a data
connection. Protocols can be assigned to each layer of
the reference model. There are communication protocols
for the bottom four layers of the reference model and
higher protocols for control and data provisioning and its
application.
Quality of Service (QoS)
QoS are all procedures that inuence the ow of data in
LANs and WANs so that the service which arrives at the
receiver is of a particular quality. The ITU has developed
a hierarchical QoS model, which takes both the technical
aspects of the service into account and the availability and
handling of the terminal equipment. The ITU dened three
QoS classes on this basis.
Rapid Spanning Tree
The IEEE Standard Rapid Spanning Tree protocol (RSTP,
IEEE 802.3w) is – apart from RapidRing™ – another option
to provide redundancy in a network. The RSTP makes a
structure similar to the network possible. In this way multi-
redundancy can be achieved. Using RSTP in a network is not
as simple as using RapidRing™, but RSTP does have a lot of
interesting options.
Remote Management
Remote Management of a switch from every network
station equipped with Telnet or web browsers. Remote
Management assumes that each switch has its own IP
address.
RJ45
The advantages of the RJ45 slot system are its compactness
and simplicity. It is used for horizontal wiring and wiring
work places. The RJ45 slot system is an eight pole miniature
slot system for use in connections with SDP and UTP cables.
The plug’s eight contacts have serial numbers and are
protected from corrosion and mechanical stress with a thin
gold layer. The contact points are situated between guide
rails and the cable is connected with insulation piercing. On
the side opposite to the contact side, the RJ45 plug has a
uke that locks the slot when sticking it into a RJ45 jack.
RMON
Remote Monitoring is a standard for network management
and an extension of SNMP MIB for proactive monitoring and
diagnosis of distributed networks.
SC-plug-in connection
The SC-plug is a small polarised push/pull plug with high
packing density. This LWL-plug is square and can be used for
multimode bres and monomode bres. Typical insertion loss is
at 0.2 dB to 0.4 dB, operating loss in monomode bres at 50 dB
and multimode bres at least 40 dB. If monomode bres with
a skew angle coupler are used instead of an oval coupler, the
operating loss increases to at least 70 dB. In the duplex type, as
a SC-Duplex plug, the plug must be used where there is bre-
optic wiring to the terminal equipment. It is also increasingly
used in new installations and in FCS and ATM applications.
Glossary
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Technical appendix
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