[c-nsp] Increasing hold-queue to alleviate microbursts with small hardware queues

[John Neiberger]

On Aug 17, 2012 7:57 AM, "Phil Mayers" <p.mayers at imperial.ac.uk> wrote:
>
> On 17/08/12 14:48, John Neiberger wrote:
>>
>> Thanks, I suspected that was the case or it would have been mentioned
>> before. We have played around with different queuing parameters and
>> queue depths, but I'm trying to find some other potential solutions.
>>
>> Would a shaping service policy work for this? I'm wondering what the
>> impact would be on microbursts if we enabled shaping. Would that give us
>> any additional short-term buffer space?
>
>
> Can you be more specific here? >Where would you shape?

I was wondering if an outbound shaping policy on the 1g links would smooth
out the peaks of those bursts prior to them hitting the small hardware
queue. I'm just kind of thinking out loud.

Our approach at the moment is to map everything to the same queue and give
it all the queue space, except for the 15 percent that the priority queue
gets. We can't disable mls qos because other features depend on it.