Subject: [tsvwg] PSA pt 1: for better videoconferencing at home on slow links

From: Dave Taht <[email-masked]>
Date: Fri, 24 Apr 2020 11:51:12 -0700

As y'all know, my principal concern regarding fixing bufferbloat
has mostly centered around making interactive traffic better, like dns,
voip, and videoconferencing, and not really on "making tcp go way fast".

Since yer all stuck at home now doing videoconferencing
every day, and I, at least, have seen terrible videoconference after
videoconference all month... particularly from those on LTE....

I would be curious to know who of the ietf contingent has done
things like check for bufferbloat on their home links and fix it?

dslreports.com has the best web based bufferbloat related test I know of.
If you could send along your score, and what, if anything
you've done to mitigate it, that would be great!

The dslreports report on bufferbloat worldwide can be had at:

http://www.dslreports.com/speedtest/results/bufferbloat?up=1

The data is biased in a couple ways in that we use that site a lot
to tune up our sqm implementations, and they throw out a lot of data
they consider to be "insane".

For more professional analyses, particularly at rates well above 200Mbit,
bufferbloat.net recommends the flent.org and irtt tools and "rrul" test,
in particular, and using your own servers as targets. There IS
a worldwide flent fleet up as viable low bandwidth targets, but...

if anyone has a spare 10Gbit server in their dc we could add in for
more testers and testing, please let me know offlist?

Some random recommendations for better videoconferencing at home:

* use wires! wifi and lte can really suck.

* get LOTS more bandwidth!

* Banish everyone else from the network while videoconferencing! Or...

-- 
Make Music, Not War

Dave Täht
CTO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-831-435-0729

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From: Steven Blake <[email-masked]>
Date: Fri, 24 Apr 2020 16:14:35 -0400

> they consider to be "insane".

http://www.dslreports.com/speedtest/62783231

Go ahead, hate me.

Regards,

// Steve

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From: Brian E Carpenter <[email-masked]>
Date: Sat, 25 Apr 2020 08:47:34 +1200

Here's a straight comparison, same laptop, same everything, three minutes apart.
The first one is Ethernet to my FritzBox, the second one is WiFi over a range
of about one metre.
http://www.dslreports.com/speedtest/62783788
http://www.dslreports.com/speedtest/62783923

Spot the difference.

Regards
   Brian Carpenter

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From: Dave Taht <[email-masked]>
Date: Fri, 24 Apr 2020 14:06:51 -0700

thx brian!

> http://www.dslreports.com/speedtest/62783923

Pretty good for dsl! your wifi is so much faster than the uplink so
its hard to notice a difference. Still kind of looks like sfq though.

At least some models of the fritzbox have fq_codel in 'em (
https://forums.whirlpool.net.au/archive/2754137 ), do you have ssh
access to the box?
ip addr # will show the underlying qdisc
tc -s qdisc show # give qdisc stats

enabling ecn, doing a packet capture, and repeating the test might be
interesting.

-- 
Make Music, Not War

Dave Täht
CTO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-831-435-0729

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From: Dave Taht <[email-masked]>
Date: Fri, 24 Apr 2020 14:23:43 -0700

> http://www.dslreports.com/speedtest/62783231

Just jealous.

Could you repeat that test, at the fiber setting, over your wifi both
from near and a few walls away?

-- 
Make Music, Not War

Dave Täht
CTO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-831-435-0729