System information

260 Selected Probe or SNMP Device Properties
• “Maximum capture buffer (MB)”—displays the maximum capture buffer Observer
will allow you to configure. Observer has no limitations on the amount of RAM that
can be used for a buffer. The maximum allowable buffer size is displayed in the
Options > Selected Probe or SNMP Device Properties > Probe Parameters tab. The
following formulas are used to calculate the maximum allowable buffer:
For Observer:
Maximum Buffer Size = (Total Physical Memory—18MB) *.4. The total amount
allocated cannot exceed 100 MB.
For Expert Observer and Observer Suite:
You can allocate up to 4 gigabytes, limited only by the physical memory installed on your
system.
In all cases, the actual buffer size (Max Buffer Size) is also reduced by 7% for
memory management purposes. Should you try and exceed the Max Buffer Size an
error dialog will be displayed indicating the minimum and maximum buffer size for
your Observer (or Probe) buffer.
• “Network errors the NIC NDIS driver claims to provide”—displays the aggregate
errors that your NDIS driver claims to provide statistics for.
Adapter Speed Tab
The Adapter Speed tab contains a dropdown box from which you can choose to let
Observer and the NIC card automatically determine the network speed, or to select from
various values (in megabits per second) for the network speed to be used for calculations.
The primary use of this is to correct a mistaken NIC card’s impression of
overall network speed. An NIC card connected to a 10 megabit hub on a
gigabit network, for example, will think that the entire network is only 1% as
fast as it actually is.