<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><blockquote type="cite" class="">On 21 Dec, 2018, at 12:37 pm, Shefali Gupta <<a href="mailto:shefaligups11@gmail.com" class="">shefaligups11@gmail.com</a>> wrote:<br class=""><br class="">In the meantime, we have added the following plots to our wiki:<br class=""><br class="">1. Number of packet drops per time interval<br class=""><br class="">Link: <a href="https://github.com/Daipu/COBALT/wiki/Proactive-Drop-Count-per-time-interval-graphs" class="">https://github.com/Daipu/COBALT/wiki/Proactive-Drop-Count-per-time-interval-graphs</a><br class=""><br class="">2. A file showing the timestamp of each drop<br class=""><br class="">Link: https://github.com/Daipu/COBALT/wiki/Drop-Timestamp-Files<br class=""></blockquote><br class=""><div class="">Interesting - but very very odd. COBALT is apparently not behaving anything like as designed.</div><div class=""><br class=""></div><div class="">As an immediate point, the first drop occurs 2 whole seconds later than either Codel or PIE, which is completely at odds with the excellent control of the initial slow-start phase seen in other graphs.</div><div class=""><br class=""></div><div class="">I took the timestamp files, dumped them into a spreadsheet column each, and plotted 1/(T(n)-T(n-1)) for each drop event against the raw timestamps. This yields a view of the instantaneous drop frequency. Because PIE sometimes drops multiple packets at once, yielding very high values here, I truncated the Y-axis at 1000 Hz.</div><div class=""><br class=""></div><div class="">The Codel implementation shows the expected behaviour of a linear ramp of drop frequency over time during its dropping phases. The COBALT implementation does not. Indeed, during a single phase, COBALT's dropping frequency appears to vary chaotically, as if it is implementing random-drop instead of timed drops.</div><div class=""><br class=""></div><div class=""><img apple-inline="yes" id="E3694C01-3787-46D6-9B13-0861CA88195C" src="cid:0712D25E-0EDE-4765-89A6-3B586BC24D01@lan" class=""></div><div class=""><br class=""></div><div class=""> - Jonathan Morton</div><div class=""><br class=""></div></body></html>