Software router state of the art

Wed Jul 23 16:50:37 UTC 2008

Valdis.Kletnieks at vt.edu wrote:
> On Wed, 23 Jul 2008 02:52:56 PDT, Zed Usser said:
>> There's been some discussion on the list regarding software routers
> 
> The performance of "software routers" has always had a hardware component.
> 
> Basically, for the vast majority of them, take your PCI bus bandwidth,
> count how many times a packet has to cross it, and do the math.  You can't
> forward more than that much traffic no matter *what* software you run on
> that box.  If that number falls short, stop right there and look for
> some box of different design that has the required backplane bandwidth.
> 
> You will, of course, take additional performance hits due to locking issues
> and similar in your software stack (that, and most "software" routers will
> suffer from not having special hardware assist for routing table lookups).

The current state of the art is around 2 million pps for fast intel arch 
system.

> Let us know if you find a suitable chassis/motherboard that has enough
> bandwidth to make it worth thinking about for anything other than the
> smaller edge routers that most providers have zillions of... :)
> 