Hello Jonathan, Thanks for your feedback.
As suggested, we have produced CoDel and PIE graphs with small NIC buffer and uploaded the corresponding graphs. Link: https://github.com/Daipu/COBALT/wiki/Link-Utilization-Graphs-with-Different-NetDeviceQueue-size We have also uploaded one way end-to-end dela*y* graphs in Light traffic scenario for CoDel, COBALT and PIE. Link: https://github.com/Daipu/COBALT/wiki/End-To-End-Delay-Graphs Thanks a lot for your help. We really appreciate it. Regards, Shefali Gupta Jendaipou Palme On Mon, Dec 10, 2018 at 8:45 PM Jonathan Morton <chromati...@gmail.com> wrote: > > On 10 Dec, 2018, at 2:30 pm, Jendaipou Palmei <jendaipoupal...@gmail.com> > wrote: > > > > As suggested, we changed the NIC buffer size to 1 packet for the > simulation and also tried these different buffer sizes: 10, 50 and 75. > > > > The default NIC buffer size in ns-3 is 100 packets. > > > > Additionally, we also enabled BQL and tried. > > > > We see that the link utilization gets significantly affected when we > keep the NIC buffer size small. > > Yes, that's what I'd expect to see from Reno-type congestion control, and > is one good reason why alternatives to Reno were developed (eg. Compound, > CUBIC, BBR). You may wish to explore what happens with Compound and CUBIC, > once your basic measurement methodology has matured. > > I would suggest using BQL, since it's available and represents a realistic > deployment. > > If you were to add TCP (or parallel UDP/ICMP) RTT measurements, you'd see > that the peak latency was correspondingly improved by removing the dumb > FIFO hidden within the NIC. I estimate that a 100-packet buffer accounts > for about 120ms of latency at 10Mbps, which should definitely be visible on > such a graph (being almost 250% of your baseline 50ms latency). > > Since latency is the main point of adding AQM, I'm a little surprised that > you haven't already produced graphs of that sort. They would have > identified this problem much earlier. > > At present you only have COBALT graphs with the small NIC buffer. For a > fair comparison, Codel and PIE graphs should be (re-)produced with the same > conditions. The older graphs made with the large NIC buffer are > potentially misleading, especially with respect to throughput. > > - Jonathan Morton > > _______________________________________________ > Cake mailing list > Cake@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/cake >
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