Power save? On Tue, Jan 16, 2018 at 11:36 AM, Arie <nos...@ariekanarie.nl> wrote: > Recently I accidentally discovered something quite odd about my home DOCSIS > connection (shaped with cake) while running a flent rrul test. > During the flent rrul test, another machine in my home had started a Steam > game update, this opened somewhere between 8-12 connections and saturated my > downstream. > > The interesting part was the resulting rrul graph, showing perfect latency > control during the test, but 100-150ms of bufferbloat at the very start and > end of the rrul graph (when rrul is idle, just pinging). > > Instead of a Steam download I started an iperf3 client on a remote machine > that opened 16 connections to a LAN machine. Same behavior as the Steam > download. > > At first I thought this was a bug with cake, but no matter how I tuned cake > (limiting my 400/40 connection to 50/20 for example), the behavior was > similar. > I tried fq_codel+htb, and got similar results to cake, high latency before > the rrul test kicked off, great latency while rrul was doing its up and > downloads. > > So I swapped out my self-compile LEDE router with an Edgerouter ER-X with > both stock and LEDE firmware, both with fq_codel and cake (on both stock and > LEDE firmware). Same results. > Even without any SQM active, the rrul test still improved the latency of my > connection when it's also downloading from 8+ connections at the same time. > > I managed to take the flent rrul test out of the equation by starting a > hping3 "flood" to the hop next of my cable modem. > >> hping3 -2 -d 0 -s 10080 -k -p 80 -i u100 >> first-hop-or-ISP-gateway-goes-here > > > This also fixed the latency while many downloads were running by sending > about 300KB/s of empty UDP packets to some unresponsive port on my ISPs > local gateway. > > I'm puzzled by this result, somehow sending 300KB/s of empty packets > upstream drastically improves the latency of my connection when it's > receiving many downloads. > > Equipment used: > Cisco EPC3212 cable modem (8x4 EuroDOCSIS 3.0) > Linksys WRT1900ACS router with LEDE > Ubiquiti Edgerouter ER-X with both EdgeOS (stock) and LEDE > > > > > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat >
-- Dave Täht CEO, TekLibre, LLC http://www.teklibre.com Tel: 1-669-226-2619 _______________________________________________ Bloat mailing list Bloat@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/bloat