Re: Linux based router for Gigabit traffic

["Stephen J. Smoogen" <smooge@gmail.com>]

On Sun, 22 Aug 2004 08:49:04 -0400, Neil Horman <nhorman@redhat.com> wrote:
> Anantha Kiran wrote:
> 
> >Hi
> >I am doing a project, in which i have to redirect traffic coming from
>
> Quite simply a general purpose CPU system isn't  normally built to
> handle network traffic at gigabit rates, especially not from multiple
> ports at once.  If you really want a line rate gigabit router, you need

Modern CPU's can handle gigabit and by the numbers 10 gigabit traffic
for what he is wanting.  (If you use PCI-X or Express) 

It is mainly getting the PCI bus and kernel 
interrupts to deal with that speed. We are able to push through 750 mbits
on E1000 cards through netfilter on HTTP loads. The main problem is
that the card generates an IRQ per packet and the soft irq takes up 
all the CPU load. On mixed network loads we are at about 400 mbits also..
but it isnt the bus that is loaded but the number of packets per second
that the card can handle.

To find out what the bottleneck is on the system, you need to make sure
your box has the correct tools ( a top that shows soft-irq, a newer mpstat
and other items). Also make sure that the motherboard Bus is PCI-X or better.