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Choosing between a SPAN, Aggregator, or full-duplex TAP
Chapter 1 TAPs Overview
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When to use a full-duplex TAP
A full-duplex TAP is the only method of the three options that
guarantees that all of the network traffic, including Layer 1 and 2
error information, makes it to the analysis device. It is more complex
and potentially expensive to implement, but where there is high
network utilization and it is important to guarantee the capture of
“everything on the wire” along with errors from all network layers, a
full-duplex TAP is the only choice. If the analysis requires a high level
of data stream fidelity (for instance, looking for jitter in video or
VoIP), only a full duplex TAP forwards the original data timing to the
analyzer.
A full-duplex TAP is a passive mechanism that is installed between
two full-duplex network devices. An optical TAP is non-electronic (no
power) and optically splits the full-duplex signal into two full-duplex
signals. One signal maintains the network link, while the other is
passed to an analyzer equipped with a dual-receive capture card. A
copper TAP performs the same function, but uses electronic circuitry
to duplicate the signals. Because a full-duplex TAP copies both the
send and receive channels from a full-duplex link to the analyzer
(where the data is integrated), the analyzer can monitor a full-duplex
network at line rate—assuming the capture card in the analyzer is
capable of keeping up.
A full-duplex TAP must be coupled with a probe or monitoring
device capable of receiving both channels of a full-duplex signal and
recombining the two channels into a single data stream for analysis.
Although this can be the most expensive solution, it is also the only
solution that guarantees complete accuracy even when the network is
highly saturated.
All TAPs from Black Box, except the Aggregator TAPs, are full-
duplex. See
page 27 for more details about each type of full-duplex TAP.
Содержание TS250A
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Страница 7: ...Chapter 1 TAPs Overview 7 rev 1 Chapter 1 TAPs Overview ...
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Страница 27: ...Chapter 3 Optical TAPs 27 rev 1 Chapter 3 Optical TAPs ...
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Страница 51: ...Chapter 5 FAQ and Troubleshooting 51 rev 1 Chapter 5 FAQ and Troubleshooting ...
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