Subject: Re: PSA pt 1: for better videoconferencing at home on slow links

From: Dave Taht <[email-masked]>
Date: Sat, 25 Apr 2020 10:37:16 -0700

for some reason I am not getting any ietf mailing list mail. too many
useful links in the last one? :/

How bad is your dslreports test (send link privately if you like)

For openwrt: you need to install luci-app-sqm on openwrt for a gui and
the related kernel modules. You need to do a bit of testing.

opkg update
opkg install luci-ssl luci-app-sqm # I pull in the full ssl gui as well.

see configuration guide:
https://openwrt.org/docs/guide-user/network/traffic-shaping/sqm

as for autoconf, well, if ISPs shared their actual up/down rates and
encapsulations with their users with a standard message (there is one
appearing for pppoe), it would be a better world. Those ISPs
optimizing their networks dynamically should also be providing a
regular update to their users over a std api, IMHO.

There's been some really cool work recently on getting good graphs of
latency, loss, and marking, out of collectd and sch_cake:

https://forum.openwrt.org/t/sqm-reporting/59960/28

-- 
Make Music, Not War

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

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From: Michael Thomas <[email-masked]>
Date: Sat, 25 Apr 2020 11:10:11 -0700

> How bad is your dslreports test (send link privately if you like)

With the previous router iirc, it got a D or an F. no clue about actual 
number. With the openwrt+bufferbloat fix it gets an A.

Maybe your pt 2 contained info on the ISP side of the problem, but it 
was pretty dense :) a) is it a problem (i can't imagine it not being 
one) and b) are they doing anything about it?

I've figured out that out here in the boonies that our provider -- The 
Volcano Telephone Company -- has a pedestal relatively close to us that 
terminates pots, ATM and backhauls the entire thing by fiber to the CO. 
A side thing I figured out is that they used leftover copper pairs for 
to power it which works great when battery backup is needed from the CO.

What that Implies is that there is a router or something akin to it that 
has packet buffering. I assume bufferbloat is L2/L3 agnostic so even my 
little green pedestal in the forest is possibly a source of 
bufferbloat.  Is there any way on my consumer end to check for that? Or 
does the DSLreport speed test already take that into account somehow? My 
provider actually has a speed test which terminates at the CO which is 
probably more accurate, but don't think it has the specific bufferbloat 
test. It's on the fritz right now so i can't check.

> opkg install luci-ssl luci-app-sqm # I pull in the full ssl gui as well.
Yes, that looks familiar. I was pretty surprised that it wasn't enabled 
by default.

Any reason why? I mean, is this in any way contentious?

Mike

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From: Michael Thomas <[email-masked]>
Date: Sat, 25 Apr 2020 12:54:31 -0700

Dave asked to try this on my openwrt router at home. this is with SQM on 
which got A A A

http://www.dslreports.com/speedtest/62830190

this is SQM off and it got a C for bufferbloat and a B overall

http://www.dslreports.com/speedtest/62830524

Mike

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From: Dave Taht <[email-masked]>
Date: Sat, 25 Apr 2020 13:02:13 -0700

> http://www.dslreports.com/speedtest/62830524

wow, 560ms of peak bufferbloat on the down, and 240 on the up. vs
~50ms each way.

you should def try correcting for your dsl framing also. you are
leaving some bandwidth on the floor.

--
Make Music, Not War

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

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From: Michael Thomas <[email-masked]>
Date: Sat, 25 Apr 2020 13:13:51 -0700

> leaving some bandwidth on the floor.

Which knob would that be? And note the second URL is the one with SQM OFF

Mike