Jonathan Morton <chromati...@gmail.com> writes: >> On 11 Aug, 2016, at 01:05, Toke Høiland-Jørgensen <t...@toke.dk> wrote: >> >> There are cwnd reductions, yes, but are they drops? My thought was >> that they were retransmissions caused by OOO packets? > > You should be able to find the retransmitted packets, in that case. > But FQ shouldn’t be reordering packets within the same flow.
No, but the WiFi retransmission logic might. Specifically, the ath9k will put packets in a retry buffer that takes precedence over new packets when building aggregates. But since it has one or two aggregates built already by the time it does this, reordering can occur that way. Now, digging in to the packet traces (looking at the single flow case, since that is easier to follow), there's a ~320k segment of the sequence space that is about 1.5MB and 200 ms late (sequence numbers 10044929 through 10370177 show up after sequence number 11617665 at around the 12k packet mark in the trace). This is nine full aggregates being reordered. I'm not really sure the reordering mechanism described above can account for this, unless there are some pretty serious hardware buffering going on that we are not aware of. Does anyone else have any ideas? -Toke _______________________________________________ Cerowrt-devel mailing list Cerowrt-devel@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/cerowrt-devel
