GSR, 7600, Juniper M?, oh my!

Richard A Steenbergen ras at e-gerbil.net
Tue Jan 13 03:13:34 UTC 2004


On Tue, Jan 13, 2004 at 02:01:48AM +0100, Jesper Skriver wrote:
> 
> On Wed, Jan 07, 2004 at 11:44:20PM +0200, Tarko Tikan wrote:
> 
> > hello!
> >
> > > What was your CPU utilization prior to the upgrade?
> >
> > Like always before the upgrade - 95% :)
> >
> > Currently on npe-g1 it's 80% on peak times with traffic numbers I
> > mentioned before and 4500 online modems, 3000 cpe's
> 
> CPU utilization on a software based router is not linear, said in a
> different way, even when CPU hits 100% it can still forward
> significantly faster.

That would depend what is causing the CPU usage. If it is software based
IP header lookups, you're not going to get any more peformance out of it
by trying to do more lookups than your CPU can handle. If on the other
hand the CPU usage is interrupt load, then yes forwarding rates could
continue to go up even after the CPU hits 100% (assuming the priorities
aren't such that you kill the rest of the box, routing protocols etc), at
the expense of latency.

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)



More information about the NANOG mailing list