Net Optics PA-CU-AR Switch User Manual


 
10/100 Port Aggregator Tap
12
Active Response Tap FAQs (Continued)
Q: How much bandwidth is available on the Active Response Port?
A: The average amount of bandwidth for active responses is determined by
the average available capacity on the link. For example, on a 100 Mbps full-
duplex link, if transmission from device A to device B averages 30 Mbps, and
transmission from device B to device A averages at 50 Mbps, then there is an
average capacity on the rst side for 70 Mbps, and on the second side for up
to 50 Mbps of active response trafc.
At any particular point in time, actual capacity is determined by the size of the
packets being transmitted and the gap between these packets. On a standard
link with 64-byte network and active response trafc, the capacity at any point
in time will be very close to the average capacity. (We do not recommend
using the Tap on links with jumbo packets as these large – up to 9K – packets
can ll the buffer and impact performance.)
As the most common use for the Tap will be to inject TCP resets, which are
standard 64-byte packets, it is unlikely that the transmissions from either side
of the Active Response Port will exceed 10 Mbps, even if many sessions are
terminated in a short time frame. In our internal testing, we have therefore
focused on Active Response Port performance at up to 10 Mbps.
Q: Does Active Response Port require the connected monitoring device to
have an IP address?
A: Yes, the connected monitoring device is required to have a MAC and IP
address when the Active Response Port is operating in active mode. These are
not required when this Port is set to passive mode. The Tap itself never has a
MAC or IP address, regardless of how the Active Response Port is set.