[c-nsp] Cisco Router IRB

[Joe Maimon]

James Bensley wrote:
>
> I thought that IRB did use CEF on the ISR-G2s?
>
> Cheers,
> James.
>

On software routers, even CEF enabled features do not compare well with 
the most optimal and optimized routing operation flows, which is 
essentially IP in Ethernet interface, un-encapsulated, unencumbered and 
minimally modified, IP out Ethernet interface, likewise.

That is what the routerperformance.pdf is based on and you should use 
that in two ways

a) compare relative capacity ratios between platforms

b) guesstimate actual performance based upon which features in use, 
starting from those numbers as a hard ceiling and going down.

It has been said frequently that for software routers, halve performance 
for each feature in use (tic: including powering on the router)

All that aside, I would expect that IRB as a popular BRAS approach has 
been heavily optimized and actually compares well with with vanilla 
IPoE. That has been my experience.

YMMV, HTH

Joe