[Starlink] Starlink hidden buffers

[Sebastian Moeller]

Hi Michael,

> On May 24, 2023, at 20:30, Michael Richardson via Starlink <starlink at lists.bufferbloat.net> wrote:
> 
> 
> Dave Taht <dave.taht at gmail.com> wrote:
>>> Could fq_codel emit flow statistics as a side-effect of it's
>>> classifications?
> 
>> It does. It always has. "tc -s class show" gives details of each queue.
> 
> Good.
> Just a question of hooking up luci to that.

	Keep in mind by default fq_codel uses 1024 hash bins, so worst case your GUI needs to display quite a lot of units; on the other hand many flows are really short, and the "tc -s class show" has little "hysteresis" that is once a hash bin runs empty, fq_codel will not report data for that bin. (Which is fine as empty buckets tend to be not very informative, but when using this output to feed a display tool now your sampling/query rate might be too coarse and not show ephemeral buckets).


> 
>> There are some really cool things you can do at high sample rates.
>> Here is a live/realtime movie of what netflix actually looks like:
>> https://www.youtube.com/watch?v=C-2oSBr2200 (also) Another thing is
> 
> A movie about people watching movies :-)

	And a "silent move" at that, very meta and very old school ;)

> I wonder about the privacy implications of doing this at an ISP.

	I think keeping the full 5-tuple input to the hash function might be problematic, but "reducing" that to the 10bit bucket-ID should be lossy enough, no?

Regards
	Sebastian

P.S.: for cake luci statistics has grown a module that plots the outputs of `tc -s qdisc` for cake instances over time. Sure that is not the per-flow or per hash-bin resolution, but for quickly seeing whether there is on-going high level marking/dropping it should suffice...


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