[c-nsp] Further clarification on Queuing questions

[Aaron Daubman]

To try and make my previous questions less ambiguous, does anybody
have any pointers / info on where packets are queued and how they are
forwarded on a 7206 with NPE-G1?  Specifically, if CBWFQs and LLQs are
configured on an interface, where are these queued packets buffered
and what, if any, affect does the aforementioned 'hold-queue length
{in | out}' command have?

I have found several generic flowcharts/process diagrams of the 7200,
but none account for QoS, mainly just basic Forwarding and CEF...

Thanks again,
     ~Aaron

On 5/8/07, Aaron Daubman <daubman at gmail.com> wrote:
> Greetings,
>
> I'm hoping somebody can provide some detailed Information on Queuing
> commands and Cisco architectural differences.
>
> Specifically, I'm wondering what the affect of the following command
> is on different routers?
> (e.g. Particle-based 7206VXR versus GSR, etc...)
>
> Router(config-if)# hold-queue length {in | out}
>
> Also, It would be great if there were pointers or info on how CEF or
> other non-process-switching methods were/weren't affected by this
> command and why.
>
> Finally, some of the brief info I've found seems to suggest that the
> above command relates only to interfaces using FIFO queuing.  What
> affect would this command have if issued on an interface using CBWFQ
> or DWRED and why?
>
> I've found a handful of brief flowcharts without description that
> begin to explain the above but have found no comprehensive source on
> what this command does, what architectures it affects, and when it
> is/isn't appropriate.
>
> One particular statement I'd like explained is the following:
>
> """
> You can adjust the input queue size with the command hold-queue size
> input. Making the input queue significantly bigger is a perfectly
> valid solution, especially on higher-end platforms that don't use the
> input queue to switch packets.
> """
>
> What do said higher-end platforms use to switch packets and what then
> is the input queue used for?
>
> Thanks as always,
>      ~Aaron
>