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 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 wrote: > >> On Tue, Apr 5, 2022 at 8:44 AM Qian Li 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 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 >> >