It is likely it is bloat-related, as even mild bloat (as in your case) seems to expose the issue. JLasher and I, with very low/no bloat, do not have the problem.
And Bloat (added latencies under load) can and will manifest in a transient manner. You do not need to fire up 12 connections and saturate them for >10 seconds, it can all happen in bursts that measure in <1 second.
Streaming is accomplished, ironically enough, not with a steady stream on one or two connections. It is done by sending bursts of traffic and then waiting for a second or two, then another burst for a second or two, etc.
These inbound bursts generate a burst of outbound ACKs, and those pile up in the outbound queues, and without effective traffic management, will potentially suffer delays of >200ms, which is where the bloat appears.
To the streaming service, it now looks like your line was not able to keep up with the rate of the last burst, so it downshifts either or both the send rate or the quality in the payloads.
BTW- The reason streaming is done with bursts is to combat bloated lines, as if they were to go steady-state on a bloated line, the bloat just grows until the connection fails. Using bursts, the build-up in the queues can drain.
Bloat will vary throughout the day, one of the patented features in an IQrouter is the ability to dynamically adapt the Traffic management settings throughout the day. And man has that feature been exercised this past year! Lines that used to be rock-solid now need adjustments at 3pm, then again at 7:30, maybe back up at 10, then back down at 11pm. It all depends on what not only your network is doing, but often what's happening in the neighborhood.
