[Bloat] [Rpm] Airbnb

Jonathan Morton chromatix99 at gmail.com
Tue Aug 10 07:51:38 EDT 2021


> On 10 Aug, 2021, at 7:51 am, Matt Mathis via Bloat <bloat at lists.bufferbloat.net> wrote:
> 
> For years we published a "jitter" metric that I considered to be bogus, basically max_rtt - min_rtt, (which were builtin Web100 instruments).
> 
> In 2019, we transitioned from web100 to "standard" linux tcp_info, which does not capture max_rtt.   Since the web100 jitter was viewed as bogus, we did not attempt to reconstruct it, although we could have.   Designing and implementing a new latency metric was on my todo list from the beginning of that transition, but chronically preempted by more pressing problems.
> 
> It finally made it to the top of my queue which is why I am suddenly not lurking here and the new rpm list.  I was very happy to see the Apple responsiveness metric, and realized that M-Lab can implement a TCP version of it, that can be computed both in real time on future tests and retroactively over archived tests collected over the last 12 years.
> 
> This quick paper might be of interest: Preliminary Longitudinal Study of Internet Responsiveness

Intriguing.  The properly processed version of the data will probably show the trends more clearly, too.

I think there is merit in presenting the European data as well, so long as the discontinuities caused by topological/geographical alterations can be identified and indicated.  There are some particular local phenomena that I think would be reflected in that, such as the early rollout of fq_codel by free.fr.

 - Jonathan Morton


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