Re: Vyatta as a BRAS

[Mark Smith <nanog () 85d5b20a518b8f6864949bd940457dc124746ddc nosense org>]

On Sun, 18 Jul 2010 21:07:36 -0400
Tim Durack <tdurack () gmail com> wrote:

> On Sun, Jul 18, 2010 at 8:01 PM, Brett Frankenberger
> <rbf+nanog () panix com> wrote:
> > On Mon, Jul 19, 2010 at 07:13:46AM +0930, Mark Smith wrote:
> > > This document supports that. If the definition of a software router is
> > > one that doesn't have a fixed at the factory forwarding function, then
> > > the ASR1K is one.
> >
> > The code running in the ASICs on line cards in 6500-series
> > chassis isn't fixed at the factory.  Same with the code running on the
> > PFCs in those boxes.  There's not a tremendous amount of flexibility to
> > make changes after the fact, because the code is so tightly integrated
> > with the hardware, but there is some.
> >
> > (Not saying the 6500 is a software-based platform.  It's pretty clearly
> > a hardware-based platform under most peoples' definition.  But:  the
> > line is blurry.)
> >
> >     -- Brett
>
> Surely the important point for most forwarding engines is that there
> is isolation between control, management and forwarding planes?
>
> If I'm looking for a box, I want line rate forwarding on all
> interfaces. I want stateless ACLs and policing functions on the
> forwarding plane. I want to use those functions to protect the control
> and management planes. I want the control plane to cope with the
> required amount of forwarding state and churn. I want the management
> plane to be somewhat as capable as the Linux tools I run to maintain
> the network.

And that's the crux of the issue. Can the box survive if line rate
maximum PPS is being aimed at it, either for forwarding or at the
control plane? If the answer is yes, then whether it is a "software
router" or "hardware router" is academic.

> I don't honestly care whether it is a single cpu, multi-core
> multi-cpu, ASIC or NPU.
>
> That being said, for the networks I help maintain, the C6K meets most
> of those requirements. I think the N7K is movement in the right
> direction. I consider both to be L2/L3 switches :-)
>
> -- 
> Tim:>