I have not had time to play with this much more, but it remains promising. Although you dismiss the ieas of not reducing the mss as not cost effective, I think for certain kinds of traffic it it worth pursuing.
Also, based on some tests on a busy wifi network elsewhere, doing packet pacing on a per packet (rather than two packets at a time) seems interesting. What are you working on these days? On Fri, Apr 8, 2022 at 11:56 PM Qian Li <biz.tina...@gmail.com> wrote: > > Hello again, > > I have uploaded the source code to GitHub. You can find it here: > > https://github.com/tinalee77/FlexiS > > I have done some editing to the original code that was used to produce the > results in the paper. First, I removed all debugging statements. Second, I > updated comments so that they are more readable. Third, I made variable names > consistent with the paper. And finally, I licensed it with Gnu GPL. > > Best regards, > Qian > > > > > > On Thu, Apr 7, 2022 at 10:35 PM Qian Li <biz.tina...@gmail.com> wrote: >> >> Hi Dave, >> >> I was just told that I am allowed to distribute the code freely. I will >> upload it to GitHub and will send you the link as soon as I am done with it. >> >> As for the AQM test, I set the QDisc to FQ-CoDel, CoDel, and CAKE, but none >> worked on CORE. In contrast, RED and PIE worked as expected. As far as I >> know, the major difference between these two groups of AQMs is the time when >> the packets are dropped. But I am not 100% sure it was the cause. I may >> somehow test FlexiS or FlexiR (FlexiS adapted to the receiver side) on a >> testbed with various AQMs. But it will be toward the end of the adaptation I >> guess :) >> >> Best regards, >> Qian >> >> On Thu, Apr 7, 2022 at 8:52 AM Dave Taht <dave.t...@gmail.com> wrote: >>> >>> On Tue, Apr 5, 2022 at 8:44 AM Qian Li <biz.tina...@gmail.com> wrote: >>> > >>> > Dear Dave, >>> > >>> > Thank you for your interest in my work. >>> > >>> > I have read another paper authored by D. Rossi at el. presenting the >>> > priority inversion problem of LEDBAT when it is used together with AQM. >>> > And it has become one of the factors that motivated me to devise a new >>> > LBE CC that can preserve low priority even when AQM is used. >>> >>> We'd given up hope circa 2014 as of the publication of the paper I >>> cited, and moved on. >>> >>> >However, I could not test FlexiS with CoDel on the CORE emulator probably >>> >because CoDel drops packets at the dequeue time. >>> >>> I don't really understand that statement. >>> >>> > More tests should be done to verify that FlexiS does preserve low >>> > priority in the presence of various AQM algorithms. >>> >>> Yes. until fairly recently I had had a testbed setup that allowed >>> testing of various tcps and aqm systems, but its been in storage since >>> covid. >>> >>> > I am now adapting FlexiS to the receiver side. The main motivation to do >>> > so is that there might be HTTP/TCP proxies between the sender and the >>> > receiver. A receiver side LBE CC and make the connection between the >>> > proxy and the receiver LBE. In this work, I am going to tackle some open >>> > issues with FlexiS. For example, I am going to test if trend analysis can >>> > be done based on one way delay so that the throughput is less affected by >>> > ack path congestion. And I am going to evaluate various techniques to >>> > reduce rate below 2 mss per RTT. This may include what you have suggested >>> > -- use small packets and sub-packet window. I am also interested in using >>> > pacing to slow down sending rate and maybe more alternative solutions. >>> >>> Cool! >>> >>> > >>> > I don't have a git tree for the source code mainly because I don't know >>> > if I am allowed to publish the code as open source. If you are interested >>> > in the source code, I can ask the University of Oslo if I am allowed to >>> > distribute it freely? >>> >>> I would hope they would allow publication. The world is full of half >>> baked projects that if only someones new also stepped in, were >>> completed. An example of this is BBR which originally was about half >>> what it is today, until source was released among the right people. >>> >>> > >>> > Best regards, >>> > Qian >>> > >>> > >>> > >>> > On Sun, Apr 3, 2022 at 6:38 AM Dave Taht <dave.t...@gmail.com> wrote: >>> >> >>> >> Dear Qian: >>> >> >>> >> Pretty promising paper. I liked that it tackled congestion on the ack >>> >> path, among other things. >>> >> >>> >> https://www.techrxiv.org/articles/preprint/TCP_FlexiS_A_New_Approach_To_Incipient_Congestion_Detection_and_Control/19077161/1/files/33905018.pdf >>> >> >>> >> I like also that you tackled, inter-rtt fairness, and, ledbat's >>> >> latecomer advantage problem, and in fig 9, the basic problem with >>> >> delay based LBE vs AQMs (in that ledbat degrades to reno)... [1] >>> >> >>> >> Towards your conclusion... >>> >> >>> >> I have always disagreed with the "don't reduce segment size" crowd, >>> >> btw. If you have a rate where you need to go below 2mss, it doesn't >>> >> hurt the network to reduce the size of the packet, and you can keep >>> >> the signal strength up by reducing that size and continuing to sample >>> >> rtt, to respond quickly. >>> >> >>> >> Even if you are only passing a single byte of data, by lowering this >>> >> below everyone else's 2mss noise floor, you still eventually win, and >>> >> also you occupy space in packet fifos, reducing overall latency, as >>> >> bytes=time. IMHO. >>> >> >>> >> elsewhere, sub-packet windows are being experimented in bbrv2, I'm >>> >> told, but not in LBE. >>> >> >>> >> I'm also a big believer in packet pacing, and I think this is the >>> >> first paper I've seen that attempted LBE with it. Thx! >>> >> >>> >> Got a git tree? >>> >> >>> >> [1] do wish you'd had cited >>> >> https://perso.telecom-paristech.fr/drossi/paper/rossi14comnet-b.pdf >>> >> >>> >> -- >>> >> I tried to build a better future, a few times: >>> >> https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org >>> >> >>> >> Dave Täht CEO, TekLibre, LLC >>> >>> >>> >>> -- >>> I tried to build a better future, a few times: >>> https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org >>> >>> Dave Täht CEO, TekLibre, LLC -- FQ World Domination pending: https://blog.cerowrt.org/post/state_of_fq_codel/ Dave Täht CEO, TekLibre, LLC _______________________________________________ Bloat mailing list Bloat@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/bloat
