[Bloat] I have a new record for bloat

Sat Feb 11 04:04:44 EST 2017

We’ve measured timings like this on many 3GPP based systems in various countries.

It is an interaction between the radio link protocol, other parts of the 3GPP data path and way
in which such devices are integrated with the operating system (even in iOS), it is
not about the quantity of buffers but more the protocol interactions during times of stress on the
radio bearer and/or during handover.

There are protocol configuration options, different design objectives and operational management
mechanisms they _could_ use, but there is no incentive for the cellular operators to invest the
time and effort to investigate and resolve.

The same mindset that created these sort of performance artefacts is also driving changes in DSL 
standards, so watch out for these sort of artefacts (again induced by things that you have no direct
control over) starting to occur in “high speed” DSL systems (such as VDSL) when conditions are less
than perfect.

Neil

> On 31 Jan 2017, at 20:42, Jim Gettys <jg at freedesktop.org <mailto:jg at freedesktop.org>> wrote:
> 
> 
> 
> On Tue, Jan 31, 2017 at 3:13 PM, Dave Taht <dave.taht at gmail.com <mailto:dave.taht at gmail.com>> wrote:
> On Tue, Jan 31, 2017 at 12:02 PM, Aaron Wood <woody77 at gmail.com <mailto:woody77 at gmail.com>> wrote:
> > This is wifi tethering from my OSX laptop to my iPhone, right after the
> > laptop tried to reconnect to the iphone after waking up.
> >
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=0 ttl=56 time=42907.196 ms
> 
> Not even close for the record as we got something like 800 seconds out
> of gogo-in-flight. But as for wifi + tethering, you "win", I guess.
> 
> I measured GoGo a couple years ago at about 740 seconds(!).
> 
> IIRC, we've seen some other cellular systems with bloat at >60 seconds.
> 
> I don't understand what I'm seeing at the moment on my Pixel XL on T-Mobile (upstream).  I need to retake the data and post it along with the qdisc structure on current Android, for people to mull over.
>                                     - Jim
> 
> 
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=1 ttl=56 time=41922.290 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=2 ttl=56 time=40971.714 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=3 ttl=56 time=39967.402 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=4 ttl=56 time=38964.115 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=5 ttl=56 time=37986.640 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=6 ttl=56 time=37026.309 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=7 ttl=56 time=36073.683 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=8 ttl=56 time=35075.141 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=17 ttl=56 time=26273.867 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=18 ttl=56 time=25268.726 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=19 ttl=56 time=24270.618 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=20 ttl=56 time=23269.550 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=21 ttl=56 time=22265.406 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=22 ttl=56 time=21264.648 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=23 ttl=56 time=20305.022 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=24 ttl=56 time=19316.740 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=26 ttl=56 time=17310.953 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=25 ttl=56 time=18316.163 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=27 ttl=56 time=16320.196 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=28 ttl=56 time=15409.592 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=29 ttl=56 time=14411.919 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=30 ttl=56 time=13505.362 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=31 ttl=56 time=12505.893 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=32 ttl=56 time=11502.744 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=33 ttl=56 time=10501.390 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=34 ttl=56 time=9560.551 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=35 ttl=56 time=8566.430 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=36 ttl=56 time=7570.286 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=37 ttl=56 time=6588.928 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=38 ttl=56 time=5643.342 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=39 ttl=56 time=4639.435 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=40 ttl=56 time=3722.169 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=41 ttl=56 time=2719.881 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=42 ttl=56 time=1806.913 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=43 ttl=56 time=1218.198 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=55 ttl=43 time=1030.052 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=56 ttl=43 time=638.601 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=57 ttl=43 time=216.295 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=58 ttl=43 time=200.674 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=59 ttl=43 time=797.261 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=60 ttl=43 time=992.238 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=61 ttl=43 time=1696.089 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=62 ttl=43 time=1139.896 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=63 ttl=43 time=588.823 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=64 ttl=43 time=663.070 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=65 ttl=43 time=782.507 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=66 ttl=43 time=426.705 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=67 ttl=43 time=220.192 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=68 ttl=43 time=228.405 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=69 ttl=43 time=130.555 ms
> > 64 bytes from 8.8.8.8 <http://8.8.8.8/>: icmp_seq=70 ttl=43 time=210.779 ms
> >
> > -Aaron
> >
> > _______________________________________________
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> > https://lists.bufferbloat.net/listinfo/bloat <https://lists.bufferbloat.net/listinfo/bloat>
> >
> 
> 
> 
> --
> Dave Täht
> Let's go make home routers and wifi faster! With better software!
> http://blog.cerowrt.org <http://blog.cerowrt.org/>
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