IT Baseline Protection Manual - The Information Warfare Site

Threats Catalogue Deliberate Acts Remarks
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IT-Baseline Protection Manual: Oktober 2000
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The MTBFs (Mean Time Between Failure) quoted by the manufacturers of the
components can be used to estimate the risk of failure.
In the case of hubs, there are basically two different techniques of establishing
connections between individual modules, and therefore between the segments
connected. As regards products with a passive backplane - the element which
establishes connections between modules - these backplanes provide only the
electrical connections . The control unit as such is integrated in the individual
modules. In the case of products with an active backplane, this element
provides additional functions such as configurable communications between
the modules, signal amplification etc. In general, active network components
with an active backplane are more susceptible to malfunctions than active
network components with a passive backplane. The failure of an active
backplane leads to a complete breakdown of communications within the
affected network component. In contrast, passive backplanes are designed in
such a way that only mechanical violence or force majeure (e.g. lightning) can
damage them. In many cases, component faults can be attributed to the related
power supply units, as the components require a stable power supply. For this
reason, many components are delivered with redundant power supply units or
can be refitted with them. The failure of a passive network component can
impair the availability of a network to the same extent. This applies, for
example, to cables and connectors which link segments together. Such a threat
can arise as a result of improper cable installation (e.g. non-observance of the
maximum bending radius), incorrect installation of connectors (particularly in