[Bloat] when does the CoDel part of fq_codel help in the real world?

[Luca Muscariello]

On Tue, Nov 27, 2018 at 2:49 PM Mikael Abrahamsson <swmike at swm.pp.se> wrote:

> On Tue, 27 Nov 2018, Luca Muscariello wrote:
>
> > If you, Mikael don't want more than 10ms buffer, how do you achieve that?
>
> class class-default
>    random-detect 10 ms 2000 ms
>
> That's the only thing available to me on the platforms I have. If you
> would like this improved, please reach out to the Cisco ASR9k BU and tell
> them to implement ECN and PIE (or something even better). They won't do it
> because I say so, it seems. WRED is all they give me.
>

This is a whole different discussion but if you want to have a per-user
context
at the BNG level + TM + FQ I'm not sure that kind of beast will ever exist.
Unless you have a very small user fan-out the hardware clocks could loop
over
several thousands of contexts.
You should expect those kind of features to be in the CMTS or OLT.


>
> > You change the behaviour of the source and hope flow isolation is
> available.
>
> Sorry, I only transport the packets, I don't create them.
>

I'm sure you create a lot of packets. Don't be humble.


>
> > If you just cut the buffer down to 10ms and do nothing else, the only
> thing
> > you get is a short queue and may throw away half of your link capacity.
>
> If i have lots of queue I might instead get customer complaints about high
> latency for their interactive applications.
>
> --
> Mikael Abrahamsson    email: swmike at swm.pp.se
>
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