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

[Roland Bless <roland.bless@kit.edu>]

Hi Kathie,

[long time, no see :-)]
I'm well aware of the CoDel paper and it really does a nice job
of explaining the good queue and bad queue properties. What we
found is that loss-based TCP CCs systematically build standing
queues. Their positive function is to keep up the link utilization,
their drawback is the huge queuing delay. So everyone
not aware of both papers should read them. However, if you think
something that I wrote is NOT in accordance with your findings,
please let me know.

Regards,
 Roland

On 27.11.18 at 19:44 Kathleen Nichols wrote> I have been kind of blown
away by this discussion. Jim Gettys kind of> kicked off the current wave
of dealing with full queues, dubbing it
> "bufferbloat". He wanted to write up how it happened so that people
> could start on a solution and I was enlisted to get an article written.
> We tried to draw on the accumulated knowledge of decades and use a
> context of What Jim Saw. I think the article offers some insight on
> queues (perhaps I'm biased as a co-author, but I'm not claiming any
> original insights just putting it together)
> https://queue.acm.org/detail.cfm?id=2071893
> 
> Further, in our first writing about CoDel, Van insisted on getting a
> good explanation of queues and how things go wrong. I think the figures
> and the explanation of how buffers are meant to be shock absorbers are
> very useful (yes, bias again, but I'm not saying you have to agree about
> CoDel's efficacy, just about how queues happen and why we need some
> buffer). https://queue.acm.org/detail.cfm?id=2209336
> 
> It's just kind of weird since Jim's evangelism is at the root of this
> list (and Dave's picking up the torch of course). Reading is a lost art.