Re: image stream routers

[tony sarendal <dualcyclone () gmail com>]

On 17/09/05, Lincoln Dale <ltd () interlink com au> wrote:
> Christopher J. Wolff wrote:
> > I'd be interested to know the relative pros and cons of switching packets in
> > software (Imagestream) versus handing them off to a dedicated ASIC (Cisco,
> > Juniper)
>
> [without having looked at Imagestream in any way, shape or form..]
>
> it would be _unlikely_ that any router vendor that wants to support >OC3
> could do so with the 'standard' (non-modified) linux IP stack.  if they
> are modifying the 'standard' linux IP stack then its very unlikely that
> one could do so without having to publish the source-code to it.  (i.e.
> as per GPL).
>
> 'standard' linux on standard hardware isn't capable of much more than
> 100K PPS.  sure - some folks have a few hundred packets/sec - but these
> are minimalist versus the demonstrated performance of ASIC-based
> forwarding, typically 30M-50M PPS.

Regarding software based forwarding and pps old docs from the FreeBSD
guys claim that the 1Mpps barrier can be broken on a 2.8GHz XEON, with
todays standards a mediocer pc.

http://people.freebsd.org/~andre/FreeBSD-5.3-Networking.pdf 

A collegue smartbits tested a 1GHz pc, with a full feed and 250k
simoultaneons flows it managed around 250kpps. This also with freebsd
and device polling. It sounds to me like a software based machine can
be plenty fast with good code under the hood.

/Tony

-- 
Tony Sarendal - dualcyclone () gmail com
IP/Unix
       -= The scorpion replied,
               "I couldn't help it, it's my nature" =-