Black Box TS250A, Manual, Page: 44 / 64

Choosing an Aggregator TAP buffer size
Chapter 4 Aggregator TAPs 44
rev. 1
To monitor links that are well over 50% utilization for minutes at a
time, a full-duplex TAP may be a better choice.
After the buffer is full, an Aggregator TAP will drop packets. Use
Figure 9 to choose the best buffer size for your Aggregator TAP. The
graph shows the buffer size and duration of traffic spikes that the
buffer can absorb.
N
OTE
: L
INK
S
PEEDS
The Link side and Analyzer side of the Aggregator TAP
negotiate their connections independent of each other. This
means that the Link/network side can be at a speed slower
than or up to the same speed as the Analyzer side. It cannot
be faster than the Analyzer side. This is true whether you use
a copper or optical connection to the analyzer.
For instance, if your Link/network side is at 10 Mb or 100 Mb
and your analyzer connection is 1 Gb, the TAP sends data to
the analyzer at 1 Gb, known as up-converting, and there is no
chance of over-subscribing the buffer.
If your Link/network side is 1 Gb, then your connection to
the analyzer must also be 1 Gb. It cannot be 10 Mb or 100
Mb, because the analyzer cannot receive the traffic from the
Link side fast enough.