On 21/09/16 10:39, Dave Taht wrote: > On Wed, Sep 21, 2016 at 2:06 AM, Alan Jenkins > wrote: >> are we sure - that's a fairly different algorithm and different expansion of >> the acronym... > Yes it is very different, My cryptic conclusion was a common group of names were involved in both projects (including "Neal" as well). If there wasn't _some_ connection, I think they'd have suggested changing the project name to avoid confusion. > but it appears to have had the germ of at > least one of the good ideas in the soon to be published BBR. > > "BBR detects bufferbloat by comparing its calculated correlation to a > configurable threshold (e.g., 90%) and declaring bufferbloat whenever > the value exceeds the threshold." > > "Upon detecting bufferbloat, BBR immediately sets the TCP cwnd to the > window estimate, rather than gradually reducing the sending rate as > in, for example, Proportional Rate Reduction [19]. Immediately > changing the cwnd has two advantages. 27 First, it stops packet > transmissions immediately and prevents further exacerbating the delay. > When the transmissions resume with the reduced cwnd, they should > experience shorter queuing delay. > > *Second, drastic changes in sending rate should result in sharp > differences in observed RTT, increasing the signal-to-noise ratio in > the observations and improving the correlation calculation*." > > I dunno, I'm just reading tea leaves here! I guess you're referring to PROBE_RTT. PROBE_RTT seems so obvious though, but I guess that's true of all the best ideas :). I thought I saw a few other technical links. The rate measurement is a similar idea. > can't wait for the paper! excite! Aside: just reading the code I think PROBE_RTT will synchronize with other BBR instances sharing the same bottleneck. Very cool if it works that way. (And after PROBE_RTT it randomizes the next PROBE_BW phase, to avoid the harmful kind of synchronization). > >>> video streaming experiments ran on a live, production CDN, where >>> clients included real mobile and desktop users >>> large, multinational production network >> hmm, I suppose... >> >>> ## Acknowledgments ## >>> >>> Van >>> ... >>> Eric >>> ... >> >> ok, there's clearly some overlap here :-D.