nanog mailing list archives

Re: 300+ms of hotel wifi bufferbloat - peaking at 1.5 sec!


From: Josh Reynolds <josh () spitwspots com>
Date: Mon, 01 Jun 2015 10:58:26 -0800

There's a bit of discussion on the AFMUG list about that speed test Dave. People with 500Mb, 1Gb,10Gb pipes were getting drastically different results depending on what "type" of test they did.

Josh Reynolds
CIO, SPITwSPOTS
www.spitwspots.com

On 06/01/2015 10:52 AM, Dave Taht wrote:
I did the dslreports tests on the NANOG wifi while listening to srikanth today:

http://www.dslreports.com/speedtest/593926

And my own (flent data also in this dir)...

http://snapon.lab.bufferbloat.net/~d/nanog/download_cdf.png

pretty good bandwidth. Pretty horrific latency... a couple detours
around the moon.


On Sat, May 30, 2015 at 6:59 PM, Srikanth Sundaresan
<srikanth () gatech edu> wrote:
While I agree that upload speeds aren't great, it doesn't mean that the
buffers aren't big. Buffer sizes of the order of MB's are uncalled for at
the edge, unless we're talking really high speeds. The miniscule performance
increase for single TCP flows doesn't really justify the potential increase
in latency for everyone else.


On 5/30/15 6:25 PM, Steven Tardy wrote:
There's a corollary of the bufferbloat phenomenon: buffer drain time. It's
not the size of the buffer, but how long it takes to empty. And US ISPs
continue to say "customers don't want upload speed".
If the ISP upload speed was symmetric you'd likely never notice the 1-2MB
of buffers.

I guess what I'm getting at is why do you continue to say buffers are too
big instead of saying ISP upload is too slow?


On May 30, 2015, at 1:50 PM, Dave Taht <dave.taht () gmail com> wrote:

http://www.dslreports.com/speedtest/578850

I would get a kick out of it if folk here tried this new speedtest
periodically (on the "cable" setting) during the nanog conference. ;)
There is a hires option for more detail on the resulting charts...

(or fiddled with "flent" (flent.org))

--
Dave Täht
What will it take to vastly improve wifi for everyone?
https://plus.google.com/u/0/explore/makewififast




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