click perform effects with respect to RAM

[Will Stockwell]

Hi,

In reading the TOCS Click paper, the performance section doesn't mention
the amount of memory used in the forwarding system.  Am I to interpret
this as, the amount of memory does not significantly affect the perform
within reason?  Or should I assume that it can have affect, but to what
extent it does is dependent largely on the configuration I'm using?

We're trying to setup a system for splitting a pipe of traffic on one port
based on traffic streams.  For now, we're going to use IPClassifier to
split the network block onto two seperate outports.  So we're talking
about something kind of simple like this:

split :: IPClassifier(18.0.0.0/9,
		      18.128.0.0/9.
		      -);

outq1 :: Queue -> ToDevice(eth1);
outq2 :: Queue -> ToDevice(eth2);

PollDevice(eth0) -> split;
split[0] -> outq1;
split[1] -> outq2;
split[2] -> Discard;

Forgive me if I botched the syntax a little bit, I'm no pro with this
stuff.  In may be that in the future we replace split with some kind of
custom Element that will do stream splitting based on address, port and
transport protocol information, which would probably add a good amount of
overhead.

We're pushing about 80,000 packets per second onto eth0.  The system we're
thinking of running click on is a 1.4 Ghz P4 with 512 MB of RAM.  We don't
have the memory at present, so I was curious about necessity of such an
amount for this kind of use.

Any comments you might have on the amount of memory we're considering
would be greatly appreciated.


Will Stockwell