Re: [Rpm] rpm meeting notes from last week

[Sebastian Moeller <moeller0@gmx.de>]

Hi Dave,


> On Mar 27, 2022, at 16:25, Dave Taht via Rpm <rpm@lists.bufferbloat.net> wrote:
> 
> Sasha has re-organized the meeting notes we've been taking which will
> be permanently up here:
> 
> https://docs.google.com/document/d/19K14vrBLNvX_KOdRMK_s0SCYTnj70IJ-dQubL37kQgw/edit
> 
> The public meetings continue at 10AM PDT tuesdays.
> 
> One thing came up in that meeting that bears further reflection: The
> structure of the the responsiveness test is e2e, and differentiating
> between the wifi hop and/or sourcing tests from the router - is hard.
> In the latter case, we are asking a router not only to saturate its
> network connection, but to do it using crypto, which is a mighty task
> to ask of a router that's job is primarily routing (with offloads).
> 
> A thought might be to attempt p2p tests between say, an ios phone and
> an osx laptop, which would exercise the router as a wifi router. A
> docker container for the server would be straightforward. (It's still
> hard for me to
> trust containers or vm's to run fast or accurately enough, too).
> 
> Former case is still e2e but with the icmp unreachable idea I described in wtbb.

	IIRC a number of devices, especially those that would employ hardware assists for routing/forwarding will punt ICMP processing to slow-paths unto their (slowish) CPU, so extracting RTTs from ICMP responses of such nodes will include an additional source of variance/delay... that said, IIUC TTL-games is exactly what MTR does and it mostly seems to work (albeit with the occasional un-interpretable node). So it might make sense to at least try to RTT probe the whole path?

Regards
	Sebastian


> 
> -- 
> I tried to build a better future, a few times:
> https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org
> 
> Dave Täht CEO, TekLibre, LLC
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