about the improvment of network performance

Alex Satrapa grail at goldweb.com.au
Fri Jan 18 17:27:52 EST 2002

On Friday, January 18, 2002, at 04:05 , Matthew Hawkins wrote:

> The real problem needs to be described a lot better.  Maybe the system
> is underpowered cpu-wise, has a lot of ipchains rules, and throughput is
> becoming cpu-bound.  Maybe the mss is set to 41 and all the tcp packets
> are transferring 1 byte.  Maybe the remote end is really slow.  Who 
> knows?

Let's stick to the obvious questions first ;)

But yes, you're right about needing a more powerful machine to handle 
lots of rules.  But as an example, I have a Pentium 133 running my ADSL 
connection, and when I'm downloading stuff from the office and chewing 
up all the bandwidth, the machine is sometimes using 20% of available 
processor time.  I only have 20 rules in my ppp0-in chain, and 8 rules 
in my ppp1-in chain.  ppp1 is a PPTP link to another site (my office), 
ppp0 is the PPPoE ADSL connection that ppp1 is using to talk to the 

I have no idea how much of the memory bandwidth is being used (can 
anyone tell me how to find out - is there a tool like 'top' that will 
measure FSB utilisation?), so I have no idea where any bottlenecks would 


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