* [Flent-users] D* tcp looks pretty good, on paper @ 2021-01-07 18:35 Dave Taht 2021-01-07 19:20 ` [Flent-users] " Taran Lynn 2021-01-08 15:38 ` [Flent-users] Re: [bbr-dev] " Neal Cardwell 0 siblings, 2 replies; 10+ messages in thread From: Dave Taht @ 2021-01-07 18:35 UTC (permalink / raw) To: bloat, codel, ECN-Sane, Make-Wifi-fast, flent-users, BBR Development Cc: ghosal, tflynn See: https://arxiv.org/pdf/2012.14996.pdf Things I really like: * they used flent * Using "variance" as the principal signal. This is essentially one of the great unpublished and unanalyzed improvements on the minstrel algorithm as well * Conventional ecn response * outperforms bbr on variable links Only negative so far is I haven't found any published source to it. :( Otherwise a very promising start to a year. "The choice of feedback mechanism between delay and packet loss has long been a point of contention in TCP congestion control. This has partly been resolved, as it has become increasingly evident that delay based methods are needed to facilitate modern interactive web applications. However, what has not been resolved is what control should be used, with the two candidates being the congestion window and the pacing rate. BBR is a new delay based congestion control algorithm that uses a pacing rate as its primary control and the congestion window as a secondary control. We propose that a congestion window first algorithm might give more desirable performance characteristics in situations where latency must be minimized even at the expense of some loss in throughput. To evaluate this hypothesis we introduce a new congestion control algorithm called TCP D*, which is a congestion window first algorithm that adopts BBR's approach of maximizing delivery rate while minimizing latency. In this paper, we discuss the key features of this algorithm, discuss the differences and similarity to BBR, and present some preliminary results based on a real implementation." -- "For a successful technology, reality must take precedence over public relations, for Mother Nature cannot be fooled" - Richard Feynman dave@taht.net <Dave Täht> CTO, TekLibre, LLC Tel: 1-831-435-0729 ^ permalink raw reply [flat|nested] 10+ messages in thread
* [Flent-users] Re: D* tcp looks pretty good, on paper 2021-01-07 18:35 [Flent-users] D* tcp looks pretty good, on paper Dave Taht @ 2021-01-07 19:20 ` Taran Lynn 2021-01-07 20:25 ` [Flent-users] Re: [Make-wifi-fast] " Bob McMahon 2021-01-08 15:38 ` [Flent-users] Re: [bbr-dev] " Neal Cardwell 1 sibling, 1 reply; 10+ messages in thread From: Taran Lynn @ 2021-01-07 19:20 UTC (permalink / raw) To: Dave Taht Cc: bloat, codel, ECN-Sane, Make-Wifi-fast, flent-users, BBR Development, ghosal [-- Attachment #1: Type: text/plain, Size: 2227 bytes --] The source can be found at https://github.com/lambda-11235/tcp_davis . The code mentioned in the paper can be found under the tag "arxiv_2020". The current master branch has an additional stable mode that I was testing out. On Thu, Jan 7, 2021 at 10:35 AM Dave Taht <dave.taht@gmail.com> wrote: > See: https://arxiv.org/pdf/2012.14996.pdf > > Things I really like: > > * they used flent > * Using "variance" as the principal signal. This is essentially one of > the great unpublished and unanalyzed improvements on the minstrel > algorithm as well > * Conventional ecn response > * outperforms bbr on variable links > > Only negative so far is I haven't found any published source to it. :( > > Otherwise a very promising start to a year. > > "The choice of feedback mechanism between delay and packet loss has > long been a point of contention in TCP congestion control. This has > partly been resolved, as it has become increasingly evident that delay > based methods are needed to facilitate modern interactive web > applications. However, what has not been resolved is what control > should be used, with the two candidates being the congestion window > and the pacing rate. BBR is a new delay based congestion control > algorithm that uses a pacing rate as its primary control and the > congestion window as a secondary control. We propose that a congestion > window first algorithm might give more desirable performance > characteristics in situations where latency must be minimized even at > the expense of some loss in throughput. To evaluate this hypothesis we > introduce a new congestion control algorithm called TCP D*, which is a > congestion window first algorithm that adopts BBR's approach of > maximizing delivery rate while minimizing latency. In this paper, we > discuss the key features of this algorithm, discuss the differences > and similarity to BBR, and present some preliminary results based on a > real implementation." > > > > > -- > "For a successful technology, reality must take precedence over public > relations, for Mother Nature cannot be fooled" - Richard Feynman > > dave@taht.net <Dave Täht> CTO, TekLibre, LLC Tel: 1-831-435-0729 > [-- Attachment #2: Type: text/html, Size: 2855 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
* [Flent-users] Re: [Make-wifi-fast] D* tcp looks pretty good, on paper 2021-01-07 19:20 ` [Flent-users] " Taran Lynn @ 2021-01-07 20:25 ` Bob McMahon 2021-01-07 21:41 ` Dave Taht 0 siblings, 1 reply; 10+ messages in thread From: Bob McMahon @ 2021-01-07 20:25 UTC (permalink / raw) To: Taran Lynn Cc: Dave Taht, ghosal, BBR Development, Make-Wifi-fast, ECN-Sane, bloat, codel, flent-users [-- Attachment #1.1: Type: text/plain, Size: 12903 bytes --] FYI, one can try this out using iperf 2.1 <https://sourceforge.net/projects/iperf2/> with --trip-times <https://iperf2.sourceforge.io/iperf-manpage.html>. This gives end/end delay at the application level. One can use --trip-times when clocks are sync'd to get the write to read latencies which are the latencies at the application level. Note: I set up a Raspberry Pi 4 with a GPS hat from ubutronics for solderless pulse per second <https://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html>. Then configured it as a PTP grandmaster. This cost me around $200. I also added support for a very crude --near-congestion option that paces the writes based upon the weight of the RTT. The tcp_info struct is sampled and available for other experiments though one would have to modify the source a bit. This current technique used by iperf 2.1 is designed for test networks only where all traffic is under script control. We've had too many people measuring bloat as latency. We really need separate measurements between the two phenomena, bloat vs latency, because they require different eng actions for a semiconductor supplier. Below are examples over a 10G link, first with no write pacing then with it. The server output, shown first, has the latency data (as well as the net power and little's law calculation.) (Note: use --histograms for to get full distributions.) *No write pacing* [rjmcmahon@localhost iperf2-code]$ src/iperf -s -i 1 -e ------------------------------------------------------------ Server listening on TCP port 5001 with pid 24568 Read buffer size: 128 KByte (Dist bin width=16.0 KByte) TCP window size: 85.3 KByte (default) ------------------------------------------------------------ [ 1] local 192.168.1.10%enp2s0 port 5001 connected with 192.168.1.62 port 50056 (MSS=1448) (trip-times) (sock=4) (peer 2.1.0-rc) on 2021-01-07 12:11:04 (PST) [ ID] Interval Transfer Bandwidth Burst Latency avg/min/max/stdev (cnt/size) inP NetPwr Reads=Dist [ 1] 0.00-1.00 sec 1.09 GBytes 9.34 Gbits/sec 2.959/1.180/3.681/0.388 ms (8905/131072) 3.31 MByte 394522 18480=2459:2580:2475:2354:2203:2192:1974:2243 [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 2.993/2.302/3.703/0.359 ms (8978/131072) 3.36 MByte 393209 19482=2526:2850:3102:2622:2344:2297:1867:1874 [ 1] 2.00-3.00 sec 1.10 GBytes 9.42 Gbits/sec 3.010/2.302/3.692/0.347 ms (8978/131085) 3.38 MByte 391047 19387=2563:2757:2928:2708:2432:2244:1829:1926 [ 1] 3.00-4.00 sec 1.10 GBytes 9.41 Gbits/sec 3.009/2.301/3.668/0.348 ms (8979/131060) 3.38 MByte 391094 18821=2456:2585:2660:2545:2270:2239:1906:2160 [ 1] 4.00-5.00 sec 1.10 GBytes 9.42 Gbits/sec 2.985/2.299/3.696/0.359 ms (8979/131070) 3.35 MByte 394295 19441=2509:2886:2959:2728:2336:2200:1971:1852 [ 1] 5.00-6.00 sec 1.10 GBytes 9.41 Gbits/sec 2.977/2.258/3.671/0.363 ms (8978/131082) 3.34 MByte 395352 18509=2352:2602:2464:2380:2263:2142:2095:2211 [ 1] 6.00-7.00 sec 1.10 GBytes 9.41 Gbits/sec 2.980/2.290/3.680/0.363 ms (8978/131072) 3.34 MByte 394873 18522=2407:2499:2565:2334:2213:2268:1999:2237 [ 1] 7.00-8.00 sec 1.10 GBytes 9.42 Gbits/sec 2.980/2.253/3.702/0.362 ms (8979/131073) 3.35 MByte 394972 18615=2427:2592:2493:2460:2281:2057:2062:2243 [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 2.976/2.277/3.663/0.364 ms (8979/131065) 3.34 MByte 395443 18632=2338:2615:2647:2351:2192:2317:2063:2109 [ 1] 9.00-10.00 sec 1.10 GBytes 9.41 Gbits/sec 2.976/2.293/3.690/0.366 ms (8978/131076) 3.34 MByte 395416 18428=2281:2622:2497:2275:2178:2253:2129:2193 [ 1] 0.00-10.00 sec 11.0 GBytes 9.41 Gbits/sec 2.984/1.180/3.703/0.362 ms (89736/131072) 3.35 MByte 394014 188367=24320:26609:26793:24757:22712:22211:19916:21049 [rjmcmahon@localhost iperf2-code]src/iperf -c 192.168.1.10 --trip-times -i 1 -e ------------------------------------------------------------ Client connecting to 192.168.1.10, TCP port 5001 with pid 18961 (1 flows) Write buffer size: 131072 Byte TCP window size: 85.0 KByte (default) ------------------------------------------------------------ [ 1] local 192.168.1.62%enp2s0 port 50056 connected with 192.168.1.10 port 5001 (MSS=1448) (trip-times) (sock=3) (ct=0.41 ms) on 2021-01-07 12:11:04 (PST) [ ID] Interval Transfer Bandwidth Write/Err Rtry Cwnd/RTT NetPwr [ 1] 0.00-1.00 sec 1.09 GBytes 9.37 Gbits/sec 8937/0 0 1508K/1099 us 1065750 [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 1508K/1087 us 1082218 [ 1] 2.00-3.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 1508K/1081 us 1088225 [ 1] 3.00-4.00 sec 1.10 GBytes 9.42 Gbits/sec 8984/0 0 1508K/1085 us 1085300 [ 1] 4.00-5.00 sec 1.10 GBytes 9.42 Gbits/sec 8980/0 0 1508K/1105 us 1065182 [ 1] 5.00-6.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 1582K/1100 us 1069428 [ 1] 6.00-7.00 sec 1.10 GBytes 9.42 Gbits/sec 8979/0 0 1582K/1121 us 1049862 [ 1] 7.00-8.00 sec 1.10 GBytes 9.41 Gbits/sec 8976/0 0 1582K/1133 us 1038396 [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 8978/0 0 1582K/1115 us 1055394 [ 1] 9.00-10.00 sec 1.10 GBytes 9.42 Gbits/sec 8986/0 0 1582K/1122 us 1049744 [ 1] 0.00-10.00 sec 11.0 GBytes 9.41 Gbits/sec 89748/0 0 1582K/1122 us 1048294 *With write pacing* [rjmcmahon@localhost iperf2-code]$ src/iperf -s -i 1 -e ------------------------------------------------------------ Server listening on TCP port 5001 with pid 24702 Read buffer size: 128 KByte (Dist bin width=16.0 KByte) TCP window size: 85.3 KByte (default) ------------------------------------------------------------ [ 1] local 192.168.1.10%enp2s0 port 5001 connected with 192.168.1.62 port 50072 (MSS=1448) (trip-times) (sock=4) (peer 2.1.0-rc) on 2021-01-07 12:14:59 (PST) [ ID] Interval Transfer Bandwidth Burst Latency avg/min/max/stdev (cnt/size) inP NetPwr Reads=Dist [ 1] 0.00-1.00 sec 1.08 GBytes 9.31 Gbits/sec 0.401/0.193/2.682/0.168 ms (8876/131084) 456 KByte 2904347 19868=3296:2404:2508:2797:3559:1778:1551:1975 [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 0.400/0.219/0.627/0.053 ms (8971/131071) 460 KByte 2937822 19117=3069:2267:2307:2510:3029:1824:1683:2428 [ 1] 2.00-3.00 sec 1.09 GBytes 9.39 Gbits/sec 0.374/0.193/0.541/0.055 ms (8958/131060) 428 KByte 3143030 18942=2846:2423:2304:2417:2927:1831:1856:2338 [ 1] 3.00-4.00 sec 1.09 GBytes 9.39 Gbits/sec 0.385/0.190/0.664/0.070 ms (8952/131072) 441 KByte 3050401 19248=3041:2175:2343:2749:3320:1805:1526:2289 [ 1] 4.00-5.00 sec 1.09 GBytes 9.40 Gbits/sec 0.380/0.197/0.546/0.057 ms (8965/131075) 436 KByte 3095915 19959=3321:2398:2551:2738:3500:1840:1532:2079 [ 1] 5.00-6.00 sec 1.09 GBytes 9.39 Gbits/sec 0.369/0.198/0.536/0.051 ms (8956/131072) 423 KByte 3177431 21060=3627:2456:2886:3189:4246:1813:1190:1653 [ 1] 6.00-7.00 sec 1.09 GBytes 9.39 Gbits/sec 0.380/0.202/0.562/0.054 ms (8959/131077) 436 KByte 3086914 19263=3044:2338:2424:2505:3155:1809:1636:2352 [ 1] 7.00-8.00 sec 1.09 GBytes 9.40 Gbits/sec 0.376/0.198/0.541/0.053 ms (8965/131061) 432 KByte 3122495 19137=3079:2303:2340:2455:3017:1822:1683:2438 [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 0.381/0.208/0.576/0.054 ms (8974/131073) 438 KByte 3083767 19162=3050:2269:2392:2486:3019:1891:1667:2388 [ 1] 9.00-10.00 sec 1.09 GBytes 9.40 Gbits/sec 0.371/0.194/0.582/0.057 ms (8964/131070) 425 KByte 3169244 19143=3006:2411:2303:2462:3067:1744:1760:2390 [ 1] 0.00-10.00 sec 10.9 GBytes 9.39 Gbits/sec 0.382/0.190/2.682/0.076 ms (89544/131072) 437 KByte 3074913 194908=31380:23444:24362:26308:32839:18161:16084:22330 [rjmcmahon@localhost iperf2-code]$ src/iperf -c 192.168.1.10 --near-congestion=0.05 --trip-times -i 1 -e ------------------------------------------------------------ Client connecting to 192.168.1.10, TCP port 5001 with pid 19320 (1 flows) Write buffer size: 131072 Byte TCP near-congestion delay weight set to 0.0500 TCP window size: 85.0 KByte (default) ------------------------------------------------------------ [ 1] local 192.168.1.62%enp2s0 port 50072 connected with 192.168.1.10 port 5001 (MSS=1448) (trip-times) (sock=3) (ct=0.40 ms) on 2021-01-07 12:14:59 (PST) [ ID] Interval Transfer Bandwidth Write/Err Rtry Cwnd/RTT NetPwr [ 1] 0.00-1.00 sec 1.08 GBytes 9.31 Gbits/sec 8881/0 0 1135K/373 us 3120427 [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 8971/0 0 1135K/391 us 3007281 [ 1] 2.00-3.00 sec 1.09 GBytes 9.39 Gbits/sec 8958/0 0 1135K/331 us 3547260 [ 1] 3.00-4.00 sec 1.09 GBytes 9.39 Gbits/sec 8952/0 0 1135K/288 us 4074155 [ 1] 4.00-5.00 sec 1.09 GBytes 9.40 Gbits/sec 8965/0 0 1135K/301 us 3903855 [ 1] 5.00-6.00 sec 1.09 GBytes 9.39 Gbits/sec 8955/0 0 1135K/414 us 2835144 [ 1] 6.00-7.00 sec 1.09 GBytes 9.40 Gbits/sec 8961/0 0 1135K/470 us 2499013 [ 1] 7.00-8.00 sec 1.09 GBytes 9.40 Gbits/sec 8964/0 0 1135K/350 us 3356941 [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 8973/0 0 1135K/472 us 2491756 [ 1] 9.00-10.00 sec 1.09 GBytes 9.40 Gbits/sec 8964/0 0 1135K/402 us 2922710 [ 1] 0.00-10.00 sec 10.9 GBytes 9.39 Gbits/sec 89547/0 0 1135K/402 us 2919642 Bob On Thu, Jan 7, 2021 at 11:22 AM Taran Lynn via Make-wifi-fast < make-wifi-fast@lists.bufferbloat.net> wrote: > The source can be found at https://github.com/lambda-11235/tcp_davis . > > The code mentioned in the paper can be found under the tag "arxiv_2020". > The current master branch has an additional stable mode that I was testing > out. > > On Thu, Jan 7, 2021 at 10:35 AM Dave Taht <dave.taht@gmail.com> wrote: > >> See: https://arxiv.org/pdf/2012.14996.pdf >> >> Things I really like: >> >> * they used flent >> * Using "variance" as the principal signal. This is essentially one of >> the great unpublished and unanalyzed improvements on the minstrel >> algorithm as well >> * Conventional ecn response >> * outperforms bbr on variable links >> >> Only negative so far is I haven't found any published source to it. :( >> >> Otherwise a very promising start to a year. >> >> "The choice of feedback mechanism between delay and packet loss has >> long been a point of contention in TCP congestion control. This has >> partly been resolved, as it has become increasingly evident that delay >> based methods are needed to facilitate modern interactive web >> applications. However, what has not been resolved is what control >> should be used, with the two candidates being the congestion window >> and the pacing rate. BBR is a new delay based congestion control >> algorithm that uses a pacing rate as its primary control and the >> congestion window as a secondary control. We propose that a congestion >> window first algorithm might give more desirable performance >> characteristics in situations where latency must be minimized even at >> the expense of some loss in throughput. To evaluate this hypothesis we >> introduce a new congestion control algorithm called TCP D*, which is a >> congestion window first algorithm that adopts BBR's approach of >> maximizing delivery rate while minimizing latency. In this paper, we >> discuss the key features of this algorithm, discuss the differences >> and similarity to BBR, and present some preliminary results based on a >> real implementation." >> >> >> >> >> -- >> "For a successful technology, reality must take precedence over public >> relations, for Mother Nature cannot be fooled" - Richard Feynman >> >> dave@taht.net <Dave Täht> CTO, TekLibre, LLC Tel: 1-831-435-0729 >> > _______________________________________________ > Make-wifi-fast mailing list > Make-wifi-fast@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/make-wifi-fast -- This electronic communication and the information and any files transmitted with it, or attached to it, are confidential and are intended solely for the use of the individual or entity to whom it is addressed and may contain information that is confidential, legally privileged, protected by privacy laws, or otherwise restricted from disclosure to anyone else. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, you are hereby notified that any use, copying, distributing, dissemination, forwarding, printing, or copying of this e-mail is strictly prohibited. If you received this e-mail in error, please return the e-mail to the sender, delete it from your computer, and destroy any printed copy of it. [-- Attachment #1.2: Type: text/html, Size: 15306 bytes --] [-- Attachment #2: S/MIME Cryptographic Signature --] [-- Type: application/pkcs7-signature, Size: 4163 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
* [Flent-users] Re: [Make-wifi-fast] D* tcp looks pretty good, on paper 2021-01-07 20:25 ` [Flent-users] Re: [Make-wifi-fast] " Bob McMahon @ 2021-01-07 21:41 ` Dave Taht 2021-01-07 22:22 ` Bob McMahon 2021-01-08 14:35 ` [Flent-users] Re: [Ecn-sane] " Rodney W. Grimes 0 siblings, 2 replies; 10+ messages in thread From: Dave Taht @ 2021-01-07 21:41 UTC (permalink / raw) To: Bob McMahon Cc: Taran Lynn, ghosal, BBR Development, Make-Wifi-fast, ECN-Sane, bloat, codel, flent-users [-- Attachment #1: Type: text/plain, Size: 13625 bytes --] This is through one of the last remaining cerowrt boxes in the world, running fq_codel. tcp-davis takes about a 20% single stream throughput hit vs bbr. I note, that I don't care one whit about throughput anymore. I care that nothing, NOTHING messes up my videoconference... and thus the tcp-rtt stats attached for davis are pleasing. On Thu, Jan 7, 2021 at 12:26 PM Bob McMahon <bob.mcmahon@broadcom.com> wrote: > > FYI, one can try this out using iperf 2.1 with --trip-times. This gives end/end delay at the application level. One can use --trip-times when clocks > are sync'd to get the write to read latencies which are the latencies at the application level. > > Note: I set up a Raspberry Pi 4 with a GPS hat from ubutronics for solderless pulse per second. Then configured it as a PTP grandmaster. This cost me around $200. > > I also added support for a very crude --near-congestion option that paces the writes based upon the weight of the RTT. The tcp_info struct is sampled and available > for other experiments though one would have to modify the source a bit. This current technique used by iperf 2.1 is designed for test networks only where all > traffic is under script control. We've had too many people measuring bloat as latency. We really need separate measurements between the two phenomena, > bloat vs latency, because they require different eng actions for a semiconductor supplier. > > Below are examples over a 10G link, first with no write pacing then with it. The server output, shown first, has the latency data (as well as the net power > and little's law calculation.) (Note: use --histograms for to get full distributions.) > > No write pacing > > [rjmcmahon@localhost iperf2-code]$ src/iperf -s -i 1 -e > ------------------------------------------------------------ > Server listening on TCP port 5001 with pid 24568 > Read buffer size: 128 KByte (Dist bin width=16.0 KByte) > TCP window size: 85.3 KByte (default) > ------------------------------------------------------------ > [ 1] local 192.168.1.10%enp2s0 port 5001 connected with 192.168.1.62 port 50056 (MSS=1448) (trip-times) (sock=4) (peer 2.1.0-rc) on 2021-01-07 12:11:04 (PST) > [ ID] Interval Transfer Bandwidth Burst Latency avg/min/max/stdev (cnt/size) inP NetPwr Reads=Dist > [ 1] 0.00-1.00 sec 1.09 GBytes 9.34 Gbits/sec 2.959/1.180/3.681/0.388 ms (8905/131072) 3.31 MByte 394522 18480=2459:2580:2475:2354:2203:2192:1974:2243 > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 2.993/2.302/3.703/0.359 ms (8978/131072) 3.36 MByte 393209 19482=2526:2850:3102:2622:2344:2297:1867:1874 > [ 1] 2.00-3.00 sec 1.10 GBytes 9.42 Gbits/sec 3.010/2.302/3.692/0.347 ms (8978/131085) 3.38 MByte 391047 19387=2563:2757:2928:2708:2432:2244:1829:1926 > [ 1] 3.00-4.00 sec 1.10 GBytes 9.41 Gbits/sec 3.009/2.301/3.668/0.348 ms (8979/131060) 3.38 MByte 391094 18821=2456:2585:2660:2545:2270:2239:1906:2160 > [ 1] 4.00-5.00 sec 1.10 GBytes 9.42 Gbits/sec 2.985/2.299/3.696/0.359 ms (8979/131070) 3.35 MByte 394295 19441=2509:2886:2959:2728:2336:2200:1971:1852 > [ 1] 5.00-6.00 sec 1.10 GBytes 9.41 Gbits/sec 2.977/2.258/3.671/0.363 ms (8978/131082) 3.34 MByte 395352 18509=2352:2602:2464:2380:2263:2142:2095:2211 > [ 1] 6.00-7.00 sec 1.10 GBytes 9.41 Gbits/sec 2.980/2.290/3.680/0.363 ms (8978/131072) 3.34 MByte 394873 18522=2407:2499:2565:2334:2213:2268:1999:2237 > [ 1] 7.00-8.00 sec 1.10 GBytes 9.42 Gbits/sec 2.980/2.253/3.702/0.362 ms (8979/131073) 3.35 MByte 394972 18615=2427:2592:2493:2460:2281:2057:2062:2243 > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 2.976/2.277/3.663/0.364 ms (8979/131065) 3.34 MByte 395443 18632=2338:2615:2647:2351:2192:2317:2063:2109 > [ 1] 9.00-10.00 sec 1.10 GBytes 9.41 Gbits/sec 2.976/2.293/3.690/0.366 ms (8978/131076) 3.34 MByte 395416 18428=2281:2622:2497:2275:2178:2253:2129:2193 > [ 1] 0.00-10.00 sec 11.0 GBytes 9.41 Gbits/sec 2.984/1.180/3.703/0.362 ms (89736/131072) 3.35 MByte 394014 188367=24320:26609:26793:24757:22712:22211:19916:21049 > > > [rjmcmahon@localhost iperf2-code]src/iperf -c 192.168.1.10 --trip-times -i 1 -e > ------------------------------------------------------------ > Client connecting to 192.168.1.10, TCP port 5001 with pid 18961 (1 flows) > Write buffer size: 131072 Byte > TCP window size: 85.0 KByte (default) > ------------------------------------------------------------ > [ 1] local 192.168.1.62%enp2s0 port 50056 connected with 192.168.1.10 port 5001 (MSS=1448) (trip-times) (sock=3) (ct=0.41 ms) on 2021-01-07 12:11:04 (PST) > [ ID] Interval Transfer Bandwidth Write/Err Rtry Cwnd/RTT NetPwr > [ 1] 0.00-1.00 sec 1.09 GBytes 9.37 Gbits/sec 8937/0 0 1508K/1099 us 1065750 > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 1508K/1087 us 1082218 > [ 1] 2.00-3.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 1508K/1081 us 1088225 > [ 1] 3.00-4.00 sec 1.10 GBytes 9.42 Gbits/sec 8984/0 0 1508K/1085 us 1085300 > [ 1] 4.00-5.00 sec 1.10 GBytes 9.42 Gbits/sec 8980/0 0 1508K/1105 us 1065182 > [ 1] 5.00-6.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 1582K/1100 us 1069428 > [ 1] 6.00-7.00 sec 1.10 GBytes 9.42 Gbits/sec 8979/0 0 1582K/1121 us 1049862 > [ 1] 7.00-8.00 sec 1.10 GBytes 9.41 Gbits/sec 8976/0 0 1582K/1133 us 1038396 > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 8978/0 0 1582K/1115 us 1055394 > [ 1] 9.00-10.00 sec 1.10 GBytes 9.42 Gbits/sec 8986/0 0 1582K/1122 us 1049744 > [ 1] 0.00-10.00 sec 11.0 GBytes 9.41 Gbits/sec 89748/0 0 1582K/1122 us 1048294 > > > With write pacing > > [rjmcmahon@localhost iperf2-code]$ src/iperf -s -i 1 -e > ------------------------------------------------------------ > Server listening on TCP port 5001 with pid 24702 > Read buffer size: 128 KByte (Dist bin width=16.0 KByte) > TCP window size: 85.3 KByte (default) > ------------------------------------------------------------ > [ 1] local 192.168.1.10%enp2s0 port 5001 connected with 192.168.1.62 port 50072 (MSS=1448) (trip-times) (sock=4) (peer 2.1.0-rc) on 2021-01-07 12:14:59 (PST) > [ ID] Interval Transfer Bandwidth Burst Latency avg/min/max/stdev (cnt/size) inP NetPwr Reads=Dist > [ 1] 0.00-1.00 sec 1.08 GBytes 9.31 Gbits/sec 0.401/0.193/2.682/0.168 ms (8876/131084) 456 KByte 2904347 19868=3296:2404:2508:2797:3559:1778:1551:1975 > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 0.400/0.219/0.627/0.053 ms (8971/131071) 460 KByte 2937822 19117=3069:2267:2307:2510:3029:1824:1683:2428 > [ 1] 2.00-3.00 sec 1.09 GBytes 9.39 Gbits/sec 0.374/0.193/0.541/0.055 ms (8958/131060) 428 KByte 3143030 18942=2846:2423:2304:2417:2927:1831:1856:2338 > [ 1] 3.00-4.00 sec 1.09 GBytes 9.39 Gbits/sec 0.385/0.190/0.664/0.070 ms (8952/131072) 441 KByte 3050401 19248=3041:2175:2343:2749:3320:1805:1526:2289 > [ 1] 4.00-5.00 sec 1.09 GBytes 9.40 Gbits/sec 0.380/0.197/0.546/0.057 ms (8965/131075) 436 KByte 3095915 19959=3321:2398:2551:2738:3500:1840:1532:2079 > [ 1] 5.00-6.00 sec 1.09 GBytes 9.39 Gbits/sec 0.369/0.198/0.536/0.051 ms (8956/131072) 423 KByte 3177431 21060=3627:2456:2886:3189:4246:1813:1190:1653 > [ 1] 6.00-7.00 sec 1.09 GBytes 9.39 Gbits/sec 0.380/0.202/0.562/0.054 ms (8959/131077) 436 KByte 3086914 19263=3044:2338:2424:2505:3155:1809:1636:2352 > [ 1] 7.00-8.00 sec 1.09 GBytes 9.40 Gbits/sec 0.376/0.198/0.541/0.053 ms (8965/131061) 432 KByte 3122495 19137=3079:2303:2340:2455:3017:1822:1683:2438 > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 0.381/0.208/0.576/0.054 ms (8974/131073) 438 KByte 3083767 19162=3050:2269:2392:2486:3019:1891:1667:2388 > [ 1] 9.00-10.00 sec 1.09 GBytes 9.40 Gbits/sec 0.371/0.194/0.582/0.057 ms (8964/131070) 425 KByte 3169244 19143=3006:2411:2303:2462:3067:1744:1760:2390 > [ 1] 0.00-10.00 sec 10.9 GBytes 9.39 Gbits/sec 0.382/0.190/2.682/0.076 ms (89544/131072) 437 KByte 3074913 194908=31380:23444:24362:26308:32839:18161:16084:22330 > > > [rjmcmahon@localhost iperf2-code]$ src/iperf -c 192.168.1.10 --near-congestion=0.05 --trip-times -i 1 -e > ------------------------------------------------------------ > Client connecting to 192.168.1.10, TCP port 5001 with pid 19320 (1 flows) > Write buffer size: 131072 Byte > TCP near-congestion delay weight set to 0.0500 > TCP window size: 85.0 KByte (default) > ------------------------------------------------------------ > [ 1] local 192.168.1.62%enp2s0 port 50072 connected with 192.168.1.10 port 5001 (MSS=1448) (trip-times) (sock=3) (ct=0.40 ms) on 2021-01-07 12:14:59 (PST) > [ ID] Interval Transfer Bandwidth Write/Err Rtry Cwnd/RTT NetPwr > [ 1] 0.00-1.00 sec 1.08 GBytes 9.31 Gbits/sec 8881/0 0 1135K/373 us 3120427 > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 8971/0 0 1135K/391 us 3007281 > [ 1] 2.00-3.00 sec 1.09 GBytes 9.39 Gbits/sec 8958/0 0 1135K/331 us 3547260 > [ 1] 3.00-4.00 sec 1.09 GBytes 9.39 Gbits/sec 8952/0 0 1135K/288 us 4074155 > [ 1] 4.00-5.00 sec 1.09 GBytes 9.40 Gbits/sec 8965/0 0 1135K/301 us 3903855 > [ 1] 5.00-6.00 sec 1.09 GBytes 9.39 Gbits/sec 8955/0 0 1135K/414 us 2835144 > [ 1] 6.00-7.00 sec 1.09 GBytes 9.40 Gbits/sec 8961/0 0 1135K/470 us 2499013 > [ 1] 7.00-8.00 sec 1.09 GBytes 9.40 Gbits/sec 8964/0 0 1135K/350 us 3356941 > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 8973/0 0 1135K/472 us 2491756 > [ 1] 9.00-10.00 sec 1.09 GBytes 9.40 Gbits/sec 8964/0 0 1135K/402 us 2922710 > [ 1] 0.00-10.00 sec 10.9 GBytes 9.39 Gbits/sec 89547/0 0 1135K/402 us 2919642 > > Bob > > > On Thu, Jan 7, 2021 at 11:22 AM Taran Lynn via Make-wifi-fast <make-wifi-fast@lists.bufferbloat.net> wrote: >> >> The source can be found at https://github.com/lambda-11235/tcp_davis . >> >> The code mentioned in the paper can be found under the tag "arxiv_2020". The current master branch has an additional stable mode that I was testing out. >> >> >> On Thu, Jan 7, 2021 at 10:35 AM Dave Taht <dave.taht@gmail.com> wrote: >>> >>> See: https://arxiv.org/pdf/2012.14996.pdf >>> >>> Things I really like: >>> >>> * they used flent >>> * Using "variance" as the principal signal. This is essentially one of >>> the great unpublished and unanalyzed improvements on the minstrel >>> algorithm as well >>> * Conventional ecn response >>> * outperforms bbr on variable links >>> >>> Only negative so far is I haven't found any published source to it. :( >>> >>> Otherwise a very promising start to a year. >>> >>> "The choice of feedback mechanism between delay and packet loss has >>> long been a point of contention in TCP congestion control. This has >>> partly been resolved, as it has become increasingly evident that delay >>> based methods are needed to facilitate modern interactive web >>> applications. However, what has not been resolved is what control >>> should be used, with the two candidates being the congestion window >>> and the pacing rate. BBR is a new delay based congestion control >>> algorithm that uses a pacing rate as its primary control and the >>> congestion window as a secondary control. We propose that a congestion >>> window first algorithm might give more desirable performance >>> characteristics in situations where latency must be minimized even at >>> the expense of some loss in throughput. To evaluate this hypothesis we >>> introduce a new congestion control algorithm called TCP D*, which is a >>> congestion window first algorithm that adopts BBR's approach of >>> maximizing delivery rate while minimizing latency. In this paper, we >>> discuss the key features of this algorithm, discuss the differences >>> and similarity to BBR, and present some preliminary results based on a >>> real implementation." >>> >>> >>> >>> >>> -- >>> "For a successful technology, reality must take precedence over public >>> relations, for Mother Nature cannot be fooled" - Richard Feynman >>> >>> dave@taht.net <Dave Täht> CTO, TekLibre, LLC Tel: 1-831-435-0729 >> >> _______________________________________________ >> Make-wifi-fast mailing list >> Make-wifi-fast@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/make-wifi-fast > > > This electronic communication and the information and any files transmitted with it, or attached to it, are confidential and are intended solely for the use of the individual or entity to whom it is addressed and may contain information that is confidential, legally privileged, protected by privacy laws, or otherwise restricted from disclosure to anyone else. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, you are hereby notified that any use, copying, distributing, dissemination, forwarding, printing, or copying of this e-mail is strictly prohibited. If you received this e-mail in error, please return the e-mail to the sender, delete it from your computer, and destroy any printed copy of it. -- "For a successful technology, reality must take precedence over public relations, for Mother Nature cannot be fooled" - Richard Feynman dave@taht.net <Dave Täht> CTO, TekLibre, LLC Tel: 1-831-435-0729 [-- Attachment #2: tcp_nup-2021-01-07T132650.356720.tcp-davis.flent.gz --] [-- Type: application/gzip, Size: 33148 bytes --] [-- Attachment #3: tcp_nup-2021-01-07T133304.619697.bbr.flent.gz --] [-- Type: application/gzip, Size: 42416 bytes --] [-- Attachment #4: bbrvsdavis_bw.png --] [-- Type: image/png, Size: 40027 bytes --] [-- Attachment #5: bbrvsdavis.png --] [-- Type: image/png, Size: 48191 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
* [Flent-users] Re: [Make-wifi-fast] D* tcp looks pretty good, on paper 2021-01-07 21:41 ` Dave Taht @ 2021-01-07 22:22 ` Bob McMahon 2021-01-08 14:35 ` [Flent-users] Re: [Ecn-sane] " Rodney W. Grimes 1 sibling, 0 replies; 10+ messages in thread From: Bob McMahon @ 2021-01-07 22:22 UTC (permalink / raw) To: Dave Taht Cc: Taran Lynn, ghosal, BBR Development, Make-Wifi-fast, ECN-Sane, bloat, codel, flent-users [-- Attachment #1.1: Type: text/plain, Size: 16204 bytes --] Could be interesting to use an isochronous traffic profile as well as take histograms, using the actual end/end frame latency instead of RTT. This does require clock sync. CLIENT SPECIFIC OPTIONS*--isochronous[=**fps*:*mean*,*stdev**]*send isochronous traffic with frequency frames per second and load defined by mean and standard deviation using a log normal distribution, defaults to 60:20m,0. (Note: Here the suffixes indicate bytes/sec or bits/sec per use of uppercase or lowercase, respectively. Also the p suffix is supported to set the burst size in packets, e.g. isochronous=2:25p will send two 25 packet bursts every second, or one 25 packet burst every 0.5 seconds.)SERVER SPECIFIC OPTIONS*--histograms[=**binwidth*[u],*bincount*,[*lowerci*],[ *upperci*]]enable latency histograms for udp packets (-u), for tcp writes (with --trip-times), or for either udp or tcp with --isochronous clients. The binning can be modified. Bin widths (default 1 millisecond, append u for microseconds,) bincount is total bins (default 1000), ci is confidence interval between 0-100% (default lower 5%, upper 95%, 3 stdev 99.7%)Bob On Thu, Jan 7, 2021 at 1:41 PM Dave Taht <dave.taht@gmail.com> wrote: > This is through one of the last remaining cerowrt boxes in the world, > running fq_codel. tcp-davis takes about a 20% single stream throughput > hit vs bbr. > > I note, that I don't care one whit about throughput anymore. I care > that nothing, NOTHING messes up my videoconference... > > and thus the tcp-rtt stats attached for davis are pleasing. > > On Thu, Jan 7, 2021 at 12:26 PM Bob McMahon <bob.mcmahon@broadcom.com> > wrote: > > > > FYI, one can try this out using iperf 2.1 with --trip-times. This gives > end/end delay at the application level. One can use --trip-times when clocks > > are sync'd to get the write to read latencies which are the latencies at > the application level. > > > > Note: I set up a Raspberry Pi 4 with a GPS hat from ubutronics for > solderless pulse per second. Then configured it as a PTP grandmaster. > This cost me around $200. > > > > I also added support for a very crude --near-congestion option that > paces the writes based upon the weight of the RTT. The tcp_info struct is > sampled and available > > for other experiments though one would have to modify the source a bit. > This current technique used by iperf 2.1 is designed for test networks only > where all > > traffic is under script control. We've had too many people measuring > bloat as latency. We really need separate measurements between the two > phenomena, > > bloat vs latency, because they require different eng actions for a > semiconductor supplier. > > > > Below are examples over a 10G link, first with no write pacing then with > it. The server output, shown first, has the latency data (as well as the > net power > > and little's law calculation.) (Note: use --histograms for to get full > distributions.) > > > > No write pacing > > > > [rjmcmahon@localhost iperf2-code]$ src/iperf -s -i 1 -e > > ------------------------------------------------------------ > > Server listening on TCP port 5001 with pid 24568 > > Read buffer size: 128 KByte (Dist bin width=16.0 KByte) > > TCP window size: 85.3 KByte (default) > > ------------------------------------------------------------ > > [ 1] local 192.168.1.10%enp2s0 port 5001 connected with 192.168.1.62 > port 50056 (MSS=1448) (trip-times) (sock=4) (peer 2.1.0-rc) on 2021-01-07 > 12:11:04 (PST) > > [ ID] Interval Transfer Bandwidth Burst Latency > avg/min/max/stdev (cnt/size) inP NetPwr Reads=Dist > > [ 1] 0.00-1.00 sec 1.09 GBytes 9.34 Gbits/sec > 2.959/1.180/3.681/0.388 ms (8905/131072) 3.31 MByte 394522 > 18480=2459:2580:2475:2354:2203:2192:1974:2243 > > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec > 2.993/2.302/3.703/0.359 ms (8978/131072) 3.36 MByte 393209 > 19482=2526:2850:3102:2622:2344:2297:1867:1874 > > [ 1] 2.00-3.00 sec 1.10 GBytes 9.42 Gbits/sec > 3.010/2.302/3.692/0.347 ms (8978/131085) 3.38 MByte 391047 > 19387=2563:2757:2928:2708:2432:2244:1829:1926 > > [ 1] 3.00-4.00 sec 1.10 GBytes 9.41 Gbits/sec > 3.009/2.301/3.668/0.348 ms (8979/131060) 3.38 MByte 391094 > 18821=2456:2585:2660:2545:2270:2239:1906:2160 > > [ 1] 4.00-5.00 sec 1.10 GBytes 9.42 Gbits/sec > 2.985/2.299/3.696/0.359 ms (8979/131070) 3.35 MByte 394295 > 19441=2509:2886:2959:2728:2336:2200:1971:1852 > > [ 1] 5.00-6.00 sec 1.10 GBytes 9.41 Gbits/sec > 2.977/2.258/3.671/0.363 ms (8978/131082) 3.34 MByte 395352 > 18509=2352:2602:2464:2380:2263:2142:2095:2211 > > [ 1] 6.00-7.00 sec 1.10 GBytes 9.41 Gbits/sec > 2.980/2.290/3.680/0.363 ms (8978/131072) 3.34 MByte 394873 > 18522=2407:2499:2565:2334:2213:2268:1999:2237 > > [ 1] 7.00-8.00 sec 1.10 GBytes 9.42 Gbits/sec > 2.980/2.253/3.702/0.362 ms (8979/131073) 3.35 MByte 394972 > 18615=2427:2592:2493:2460:2281:2057:2062:2243 > > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec > 2.976/2.277/3.663/0.364 ms (8979/131065) 3.34 MByte 395443 > 18632=2338:2615:2647:2351:2192:2317:2063:2109 > > [ 1] 9.00-10.00 sec 1.10 GBytes 9.41 Gbits/sec > 2.976/2.293/3.690/0.366 ms (8978/131076) 3.34 MByte 395416 > 18428=2281:2622:2497:2275:2178:2253:2129:2193 > > [ 1] 0.00-10.00 sec 11.0 GBytes 9.41 Gbits/sec > 2.984/1.180/3.703/0.362 ms (89736/131072) 3.35 MByte 394014 > 188367=24320:26609:26793:24757:22712:22211:19916:21049 > > > > > > [rjmcmahon@localhost iperf2-code]src/iperf -c 192.168.1.10 --trip-times > -i 1 -e > > ------------------------------------------------------------ > > Client connecting to 192.168.1.10, TCP port 5001 with pid 18961 (1 flows) > > Write buffer size: 131072 Byte > > TCP window size: 85.0 KByte (default) > > ------------------------------------------------------------ > > [ 1] local 192.168.1.62%enp2s0 port 50056 connected with 192.168.1.10 > port 5001 (MSS=1448) (trip-times) (sock=3) (ct=0.41 ms) on 2021-01-07 > 12:11:04 (PST) > > [ ID] Interval Transfer Bandwidth Write/Err Rtry > Cwnd/RTT NetPwr > > [ 1] 0.00-1.00 sec 1.09 GBytes 9.37 Gbits/sec 8937/0 0 > 1508K/1099 us 1065750 > > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 > 1508K/1087 us 1082218 > > [ 1] 2.00-3.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 > 1508K/1081 us 1088225 > > [ 1] 3.00-4.00 sec 1.10 GBytes 9.42 Gbits/sec 8984/0 0 > 1508K/1085 us 1085300 > > [ 1] 4.00-5.00 sec 1.10 GBytes 9.42 Gbits/sec 8980/0 0 > 1508K/1105 us 1065182 > > [ 1] 5.00-6.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 > 1582K/1100 us 1069428 > > [ 1] 6.00-7.00 sec 1.10 GBytes 9.42 Gbits/sec 8979/0 0 > 1582K/1121 us 1049862 > > [ 1] 7.00-8.00 sec 1.10 GBytes 9.41 Gbits/sec 8976/0 0 > 1582K/1133 us 1038396 > > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 8978/0 0 > 1582K/1115 us 1055394 > > [ 1] 9.00-10.00 sec 1.10 GBytes 9.42 Gbits/sec 8986/0 0 > 1582K/1122 us 1049744 > > [ 1] 0.00-10.00 sec 11.0 GBytes 9.41 Gbits/sec 89748/0 0 > 1582K/1122 us 1048294 > > > > > > With write pacing > > > > [rjmcmahon@localhost iperf2-code]$ src/iperf -s -i 1 -e > > ------------------------------------------------------------ > > Server listening on TCP port 5001 with pid 24702 > > Read buffer size: 128 KByte (Dist bin width=16.0 KByte) > > TCP window size: 85.3 KByte (default) > > ------------------------------------------------------------ > > [ 1] local 192.168.1.10%enp2s0 port 5001 connected with 192.168.1.62 > port 50072 (MSS=1448) (trip-times) (sock=4) (peer 2.1.0-rc) on 2021-01-07 > 12:14:59 (PST) > > [ ID] Interval Transfer Bandwidth Burst Latency > avg/min/max/stdev (cnt/size) inP NetPwr Reads=Dist > > [ 1] 0.00-1.00 sec 1.08 GBytes 9.31 Gbits/sec > 0.401/0.193/2.682/0.168 ms (8876/131084) 456 KByte 2904347 > 19868=3296:2404:2508:2797:3559:1778:1551:1975 > > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec > 0.400/0.219/0.627/0.053 ms (8971/131071) 460 KByte 2937822 > 19117=3069:2267:2307:2510:3029:1824:1683:2428 > > [ 1] 2.00-3.00 sec 1.09 GBytes 9.39 Gbits/sec > 0.374/0.193/0.541/0.055 ms (8958/131060) 428 KByte 3143030 > 18942=2846:2423:2304:2417:2927:1831:1856:2338 > > [ 1] 3.00-4.00 sec 1.09 GBytes 9.39 Gbits/sec > 0.385/0.190/0.664/0.070 ms (8952/131072) 441 KByte 3050401 > 19248=3041:2175:2343:2749:3320:1805:1526:2289 > > [ 1] 4.00-5.00 sec 1.09 GBytes 9.40 Gbits/sec > 0.380/0.197/0.546/0.057 ms (8965/131075) 436 KByte 3095915 > 19959=3321:2398:2551:2738:3500:1840:1532:2079 > > [ 1] 5.00-6.00 sec 1.09 GBytes 9.39 Gbits/sec > 0.369/0.198/0.536/0.051 ms (8956/131072) 423 KByte 3177431 > 21060=3627:2456:2886:3189:4246:1813:1190:1653 > > [ 1] 6.00-7.00 sec 1.09 GBytes 9.39 Gbits/sec > 0.380/0.202/0.562/0.054 ms (8959/131077) 436 KByte 3086914 > 19263=3044:2338:2424:2505:3155:1809:1636:2352 > > [ 1] 7.00-8.00 sec 1.09 GBytes 9.40 Gbits/sec > 0.376/0.198/0.541/0.053 ms (8965/131061) 432 KByte 3122495 > 19137=3079:2303:2340:2455:3017:1822:1683:2438 > > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec > 0.381/0.208/0.576/0.054 ms (8974/131073) 438 KByte 3083767 > 19162=3050:2269:2392:2486:3019:1891:1667:2388 > > [ 1] 9.00-10.00 sec 1.09 GBytes 9.40 Gbits/sec > 0.371/0.194/0.582/0.057 ms (8964/131070) 425 KByte 3169244 > 19143=3006:2411:2303:2462:3067:1744:1760:2390 > > [ 1] 0.00-10.00 sec 10.9 GBytes 9.39 Gbits/sec > 0.382/0.190/2.682/0.076 ms (89544/131072) 437 KByte 3074913 > 194908=31380:23444:24362:26308:32839:18161:16084:22330 > > > > > > [rjmcmahon@localhost iperf2-code]$ src/iperf -c 192.168.1.10 > --near-congestion=0.05 --trip-times -i 1 -e > > ------------------------------------------------------------ > > Client connecting to 192.168.1.10, TCP port 5001 with pid 19320 (1 flows) > > Write buffer size: 131072 Byte > > TCP near-congestion delay weight set to 0.0500 > > TCP window size: 85.0 KByte (default) > > ------------------------------------------------------------ > > [ 1] local 192.168.1.62%enp2s0 port 50072 connected with 192.168.1.10 > port 5001 (MSS=1448) (trip-times) (sock=3) (ct=0.40 ms) on 2021-01-07 > 12:14:59 (PST) > > [ ID] Interval Transfer Bandwidth Write/Err Rtry > Cwnd/RTT NetPwr > > [ 1] 0.00-1.00 sec 1.08 GBytes 9.31 Gbits/sec 8881/0 0 > 1135K/373 us 3120427 > > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 8971/0 0 > 1135K/391 us 3007281 > > [ 1] 2.00-3.00 sec 1.09 GBytes 9.39 Gbits/sec 8958/0 0 > 1135K/331 us 3547260 > > [ 1] 3.00-4.00 sec 1.09 GBytes 9.39 Gbits/sec 8952/0 0 > 1135K/288 us 4074155 > > [ 1] 4.00-5.00 sec 1.09 GBytes 9.40 Gbits/sec 8965/0 0 > 1135K/301 us 3903855 > > [ 1] 5.00-6.00 sec 1.09 GBytes 9.39 Gbits/sec 8955/0 0 > 1135K/414 us 2835144 > > [ 1] 6.00-7.00 sec 1.09 GBytes 9.40 Gbits/sec 8961/0 0 > 1135K/470 us 2499013 > > [ 1] 7.00-8.00 sec 1.09 GBytes 9.40 Gbits/sec 8964/0 0 > 1135K/350 us 3356941 > > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 8973/0 0 > 1135K/472 us 2491756 > > [ 1] 9.00-10.00 sec 1.09 GBytes 9.40 Gbits/sec 8964/0 0 > 1135K/402 us 2922710 > > [ 1] 0.00-10.00 sec 10.9 GBytes 9.39 Gbits/sec 89547/0 0 > 1135K/402 us 2919642 > > > > Bob > > > > > > On Thu, Jan 7, 2021 at 11:22 AM Taran Lynn via Make-wifi-fast < > make-wifi-fast@lists.bufferbloat.net> wrote: > >> > >> The source can be found at https://github.com/lambda-11235/tcp_davis . > >> > >> The code mentioned in the paper can be found under the tag > "arxiv_2020". The current master branch has an additional stable mode that > I was testing out. > >> > >> > >> On Thu, Jan 7, 2021 at 10:35 AM Dave Taht <dave.taht@gmail.com> wrote: > >>> > >>> See: https://arxiv.org/pdf/2012.14996.pdf > >>> > >>> Things I really like: > >>> > >>> * they used flent > >>> * Using "variance" as the principal signal. This is essentially one of > >>> the great unpublished and unanalyzed improvements on the minstrel > >>> algorithm as well > >>> * Conventional ecn response > >>> * outperforms bbr on variable links > >>> > >>> Only negative so far is I haven't found any published source to it. :( > >>> > >>> Otherwise a very promising start to a year. > >>> > >>> "The choice of feedback mechanism between delay and packet loss has > >>> long been a point of contention in TCP congestion control. This has > >>> partly been resolved, as it has become increasingly evident that delay > >>> based methods are needed to facilitate modern interactive web > >>> applications. However, what has not been resolved is what control > >>> should be used, with the two candidates being the congestion window > >>> and the pacing rate. BBR is a new delay based congestion control > >>> algorithm that uses a pacing rate as its primary control and the > >>> congestion window as a secondary control. We propose that a congestion > >>> window first algorithm might give more desirable performance > >>> characteristics in situations where latency must be minimized even at > >>> the expense of some loss in throughput. To evaluate this hypothesis we > >>> introduce a new congestion control algorithm called TCP D*, which is a > >>> congestion window first algorithm that adopts BBR's approach of > >>> maximizing delivery rate while minimizing latency. In this paper, we > >>> discuss the key features of this algorithm, discuss the differences > >>> and similarity to BBR, and present some preliminary results based on a > >>> real implementation." > >>> > >>> > >>> > >>> > >>> -- > >>> "For a successful technology, reality must take precedence over public > >>> relations, for Mother Nature cannot be fooled" - Richard Feynman > >>> > >>> dave@taht.net <Dave Täht> CTO, TekLibre, LLC Tel: 1-831-435-0729 > >> > >> _______________________________________________ > >> Make-wifi-fast mailing list > >> Make-wifi-fast@lists.bufferbloat.net > >> https://lists.bufferbloat.net/listinfo/make-wifi-fast > > > > > > This electronic communication and the information and any files > transmitted with it, or attached to it, are confidential and are intended > solely for the use of the individual or entity to whom it is addressed and > may contain information that is confidential, legally privileged, protected > by privacy laws, or otherwise restricted from disclosure to anyone else. If > you are not the intended recipient or the person responsible for delivering > the e-mail to the intended recipient, you are hereby notified that any use, > copying, distributing, dissemination, forwarding, printing, or copying of > this e-mail is strictly prohibited. If you received this e-mail in error, > please return the e-mail to the sender, delete it from your computer, and > destroy any printed copy of it. > > > > -- > "For a successful technology, reality must take precedence over public > relations, for Mother Nature cannot be fooled" - Richard Feynman > > dave@taht.net <Dave Täht> CTO, TekLibre, LLC Tel: 1-831-435-0729 > -- This electronic communication and the information and any files transmitted with it, or attached to it, are confidential and are intended solely for the use of the individual or entity to whom it is addressed and may contain information that is confidential, legally privileged, protected by privacy laws, or otherwise restricted from disclosure to anyone else. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, you are hereby notified that any use, copying, distributing, dissemination, forwarding, printing, or copying of this e-mail is strictly prohibited. If you received this e-mail in error, please return the e-mail to the sender, delete it from your computer, and destroy any printed copy of it. [-- Attachment #1.2: Type: text/html, Size: 19120 bytes --] [-- Attachment #2: S/MIME Cryptographic Signature --] [-- Type: application/pkcs7-signature, Size: 4163 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
* [Flent-users] Re: [Ecn-sane] [Make-wifi-fast] D* tcp looks pretty good, on paper 2021-01-07 21:41 ` Dave Taht 2021-01-07 22:22 ` Bob McMahon @ 2021-01-08 14:35 ` Rodney W. Grimes 2021-01-08 17:52 ` Bob McMahon 1 sibling, 1 reply; 10+ messages in thread From: Rodney W. Grimes @ 2021-01-08 14:35 UTC (permalink / raw) To: Dave Taht Cc: Bob McMahon, ghosal, BBR Development, Taran Lynn, Make-Wifi-fast, ECN-Sane, bloat, codel, flent-users > This is through one of the last remaining cerowrt boxes in the world, > running fq_codel. tcp-davis takes about a 20% single stream throughput > hit vs bbr. > > I note, that I don't care one whit about throughput anymore. I care > that nothing, NOTHING messes up my videoconference... IMHO it is a fools errand to place all priorty on one of throughput or delay, but it is reasonable to slightly bias the situation to defer a bit over throughput if a stable lower delay is gained. The lost of some throughput can often be made up with additional capacity, but nothing can increase the speed of light. > and thus the tcp-rtt stats attached for davis are pleasing. A questions/comment inline below about this data. > > On Thu, Jan 7, 2021 at 12:26 PM Bob McMahon <bob.mcmahon@broadcom.com> wrote: > > > > FYI, one can try this out using iperf 2.1 with --trip-times. This gives end/end delay at the application level. One can use --trip-times when clocks > > are sync'd to get the write to read latencies which are the latencies at the application level. > > > > Note: I set up a Raspberry Pi 4 with a GPS hat from ubutronics for solderless pulse per second. Then configured it as a PTP grandmaster. This cost me around $200. Ok, so that is the clock source node, could we get a better description of the network topology and end node hardware? > > I also added support for a very crude --near-congestion option that paces the writes based upon the weight of the RTT. The tcp_info struct is sampled and available > > for other experiments though one would have to modify the source a bit. This current technique used by iperf 2.1 is designed for test networks only where all > > traffic is under script control. We've had too many people measuring bloat as latency. We really need separate measurements between the two phenomena, > > bloat vs latency, because they require different eng actions for a semiconductor supplier. > > > > Below are examples over a 10G link, first with no write pacing then with it. The server output, shown first, has the latency data (as well as the net power > > and little's law calculation.) (Note: use --histograms for to get full distributions.) Is this network a 3 node physical dumb-bell, or is this in Netem or is this something more complicated? What is the inherient delay path of this network? Aka, what is D in the BDP, given the near saturation and the small window my guess is this is a simple 3 node dumb bell, but would like confirmation of that. > > > > No write pacing > > > > [rjmcmahon@localhost iperf2-code]$ src/iperf -s -i 1 -e > > ------------------------------------------------------------ > > Server listening on TCP port 5001 with pid 24568 > > Read buffer size: 128 KByte (Dist bin width=16.0 KByte) > > TCP window size: 85.3 KByte (default) > > ------------------------------------------------------------ > > [ 1] local 192.168.1.10%enp2s0 port 5001 connected with 192.168.1.62 port 50056 (MSS=1448) (trip-times) (sock=4) (peer 2.1.0-rc) on 2021-01-07 12:11:04 (PST) > > [ ID] Interval Transfer Bandwidth Burst Latency avg/min/max/stdev (cnt/size) inP NetPwr Reads=Dist > > [ 1] 0.00-1.00 sec 1.09 GBytes 9.34 Gbits/sec 2.959/1.180/3.681/0.388 ms (8905/131072) 3.31 MByte 394522 18480=2459:2580:2475:2354:2203:2192:1974:2243 > > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 2.993/2.302/3.703/0.359 ms (8978/131072) 3.36 MByte 393209 19482=2526:2850:3102:2622:2344:2297:1867:1874 > > [ 1] 2.00-3.00 sec 1.10 GBytes 9.42 Gbits/sec 3.010/2.302/3.692/0.347 ms (8978/131085) 3.38 MByte 391047 19387=2563:2757:2928:2708:2432:2244:1829:1926 > > [ 1] 3.00-4.00 sec 1.10 GBytes 9.41 Gbits/sec 3.009/2.301/3.668/0.348 ms (8979/131060) 3.38 MByte 391094 18821=2456:2585:2660:2545:2270:2239:1906:2160 > > [ 1] 4.00-5.00 sec 1.10 GBytes 9.42 Gbits/sec 2.985/2.299/3.696/0.359 ms (8979/131070) 3.35 MByte 394295 19441=2509:2886:2959:2728:2336:2200:1971:1852 > > [ 1] 5.00-6.00 sec 1.10 GBytes 9.41 Gbits/sec 2.977/2.258/3.671/0.363 ms (8978/131082) 3.34 MByte 395352 18509=2352:2602:2464:2380:2263:2142:2095:2211 > > [ 1] 6.00-7.00 sec 1.10 GBytes 9.41 Gbits/sec 2.980/2.290/3.680/0.363 ms (8978/131072) 3.34 MByte 394873 18522=2407:2499:2565:2334:2213:2268:1999:2237 > > [ 1] 7.00-8.00 sec 1.10 GBytes 9.42 Gbits/sec 2.980/2.253/3.702/0.362 ms (8979/131073) 3.35 MByte 394972 18615=2427:2592:2493:2460:2281:2057:2062:2243 > > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 2.976/2.277/3.663/0.364 ms (8979/131065) 3.34 MByte 395443 18632=2338:2615:2647:2351:2192:2317:2063:2109 > > [ 1] 9.00-10.00 sec 1.10 GBytes 9.41 Gbits/sec 2.976/2.293/3.690/0.366 ms (8978/131076) 3.34 MByte 395416 18428=2281:2622:2497:2275:2178:2253:2129:2193 > > [ 1] 0.00-10.00 sec 11.0 GBytes 9.41 Gbits/sec 2.984/1.180/3.703/0.362 ms (89736/131072) 3.35 MByte 394014 188367=24320:26609:26793:24757:22712:22211:19916:21049 > > > > > > [rjmcmahon@localhost iperf2-code]src/iperf -c 192.168.1.10 --trip-times -i 1 -e > > ------------------------------------------------------------ > > Client connecting to 192.168.1.10, TCP port 5001 with pid 18961 (1 flows) > > Write buffer size: 131072 Byte > > TCP window size: 85.0 KByte (default) > > ------------------------------------------------------------ > > [ 1] local 192.168.1.62%enp2s0 port 50056 connected with 192.168.1.10 port 5001 (MSS=1448) (trip-times) (sock=3) (ct=0.41 ms) on 2021-01-07 12:11:04 (PST) > > [ ID] Interval Transfer Bandwidth Write/Err Rtry Cwnd/RTT NetPwr > > [ 1] 0.00-1.00 sec 1.09 GBytes 9.37 Gbits/sec 8937/0 0 1508K/1099 us 1065750 > > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 1508K/1087 us 1082218 > > [ 1] 2.00-3.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 1508K/1081 us 1088225 > > [ 1] 3.00-4.00 sec 1.10 GBytes 9.42 Gbits/sec 8984/0 0 1508K/1085 us 1085300 > > [ 1] 4.00-5.00 sec 1.10 GBytes 9.42 Gbits/sec 8980/0 0 1508K/1105 us 1065182 > > [ 1] 5.00-6.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 1582K/1100 us 1069428 > > [ 1] 6.00-7.00 sec 1.10 GBytes 9.42 Gbits/sec 8979/0 0 1582K/1121 us 1049862 > > [ 1] 7.00-8.00 sec 1.10 GBytes 9.41 Gbits/sec 8976/0 0 1582K/1133 us 1038396 > > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 8978/0 0 1582K/1115 us 1055394 > > [ 1] 9.00-10.00 sec 1.10 GBytes 9.42 Gbits/sec 8986/0 0 1582K/1122 us 1049744 > > [ 1] 0.00-10.00 sec 11.0 GBytes 9.41 Gbits/sec 89748/0 0 1582K/1122 us 1048294 > > > > > > With write pacing > > > > [rjmcmahon@localhost iperf2-code]$ src/iperf -s -i 1 -e > > ------------------------------------------------------------ > > Server listening on TCP port 5001 with pid 24702 > > Read buffer size: 128 KByte (Dist bin width=16.0 KByte) > > TCP window size: 85.3 KByte (default) > > ------------------------------------------------------------ > > [ 1] local 192.168.1.10%enp2s0 port 5001 connected with 192.168.1.62 port 50072 (MSS=1448) (trip-times) (sock=4) (peer 2.1.0-rc) on 2021-01-07 12:14:59 (PST) > > [ ID] Interval Transfer Bandwidth Burst Latency avg/min/max/stdev (cnt/size) inP NetPwr Reads=Dist > > [ 1] 0.00-1.00 sec 1.08 GBytes 9.31 Gbits/sec 0.401/0.193/2.682/0.168 ms (8876/131084) 456 KByte 2904347 19868=3296:2404:2508:2797:3559:1778:1551:1975 > > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 0.400/0.219/0.627/0.053 ms (8971/131071) 460 KByte 2937822 19117=3069:2267:2307:2510:3029:1824:1683:2428 > > [ 1] 2.00-3.00 sec 1.09 GBytes 9.39 Gbits/sec 0.374/0.193/0.541/0.055 ms (8958/131060) 428 KByte 3143030 18942=2846:2423:2304:2417:2927:1831:1856:2338 > > [ 1] 3.00-4.00 sec 1.09 GBytes 9.39 Gbits/sec 0.385/0.190/0.664/0.070 ms (8952/131072) 441 KByte 3050401 19248=3041:2175:2343:2749:3320:1805:1526:2289 > > [ 1] 4.00-5.00 sec 1.09 GBytes 9.40 Gbits/sec 0.380/0.197/0.546/0.057 ms (8965/131075) 436 KByte 3095915 19959=3321:2398:2551:2738:3500:1840:1532:2079 > > [ 1] 5.00-6.00 sec 1.09 GBytes 9.39 Gbits/sec 0.369/0.198/0.536/0.051 ms (8956/131072) 423 KByte 3177431 21060=3627:2456:2886:3189:4246:1813:1190:1653 > > [ 1] 6.00-7.00 sec 1.09 GBytes 9.39 Gbits/sec 0.380/0.202/0.562/0.054 ms (8959/131077) 436 KByte 3086914 19263=3044:2338:2424:2505:3155:1809:1636:2352 > > [ 1] 7.00-8.00 sec 1.09 GBytes 9.40 Gbits/sec 0.376/0.198/0.541/0.053 ms (8965/131061) 432 KByte 3122495 19137=3079:2303:2340:2455:3017:1822:1683:2438 > > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 0.381/0.208/0.576/0.054 ms (8974/131073) 438 KByte 3083767 19162=3050:2269:2392:2486:3019:1891:1667:2388 > > [ 1] 9.00-10.00 sec 1.09 GBytes 9.40 Gbits/sec 0.371/0.194/0.582/0.057 ms (8964/131070) 425 KByte 3169244 19143=3006:2411:2303:2462:3067:1744:1760:2390 > > [ 1] 0.00-10.00 sec 10.9 GBytes 9.39 Gbits/sec 0.382/0.190/2.682/0.076 ms (89544/131072) 437 KByte 3074913 194908=31380:23444:24362:26308:32839:18161:16084:22330 > > > > > > [rjmcmahon@localhost iperf2-code]$ src/iperf -c 192.168.1.10 --near-congestion=0.05 --trip-times -i 1 -e > > ------------------------------------------------------------ > > Client connecting to 192.168.1.10, TCP port 5001 with pid 19320 (1 flows) > > Write buffer size: 131072 Byte > > TCP near-congestion delay weight set to 0.0500 > > TCP window size: 85.0 KByte (default) > > ------------------------------------------------------------ > > [ 1] local 192.168.1.62%enp2s0 port 50072 connected with 192.168.1.10 port 5001 (MSS=1448) (trip-times) (sock=3) (ct=0.40 ms) on 2021-01-07 12:14:59 (PST) > > [ ID] Interval Transfer Bandwidth Write/Err Rtry Cwnd/RTT NetPwr > > [ 1] 0.00-1.00 sec 1.08 GBytes 9.31 Gbits/sec 8881/0 0 1135K/373 us 3120427 > > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 8971/0 0 1135K/391 us 3007281 > > [ 1] 2.00-3.00 sec 1.09 GBytes 9.39 Gbits/sec 8958/0 0 1135K/331 us 3547260 > > [ 1] 3.00-4.00 sec 1.09 GBytes 9.39 Gbits/sec 8952/0 0 1135K/288 us 4074155 > > [ 1] 4.00-5.00 sec 1.09 GBytes 9.40 Gbits/sec 8965/0 0 1135K/301 us 3903855 > > [ 1] 5.00-6.00 sec 1.09 GBytes 9.39 Gbits/sec 8955/0 0 1135K/414 us 2835144 > > [ 1] 6.00-7.00 sec 1.09 GBytes 9.40 Gbits/sec 8961/0 0 1135K/470 us 2499013 > > [ 1] 7.00-8.00 sec 1.09 GBytes 9.40 Gbits/sec 8964/0 0 1135K/350 us 3356941 > > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 8973/0 0 1135K/472 us 2491756 > > [ 1] 9.00-10.00 sec 1.09 GBytes 9.40 Gbits/sec 8964/0 0 1135K/402 us 2922710 > > [ 1] 0.00-10.00 sec 10.9 GBytes 9.39 Gbits/sec 89547/0 0 1135K/402 us 2919642 > > > > Bob > > > > > > On Thu, Jan 7, 2021 at 11:22 AM Taran Lynn via Make-wifi-fast <make-wifi-fast@lists.bufferbloat.net> wrote: > >> > >> The source can be found at https://github.com/lambda-11235/tcp_davis . > >> > >> The code mentioned in the paper can be found under the tag "arxiv_2020". The current master branch has an additional stable mode that I was testing out. > >> > >> > >> On Thu, Jan 7, 2021 at 10:35 AM Dave Taht <dave.taht@gmail.com> wrote: > >>> > >>> See: https://arxiv.org/pdf/2012.14996.pdf > >>> > >>> Things I really like: > >>> > >>> * they used flent > >>> * Using "variance" as the principal signal. This is essentially one of > >>> the great unpublished and unanalyzed improvements on the minstrel > >>> algorithm as well > >>> * Conventional ecn response > >>> * outperforms bbr on variable links > >>> > >>> Only negative so far is I haven't found any published source to it. :( > >>> > >>> Otherwise a very promising start to a year. > >>> > >>> "The choice of feedback mechanism between delay and packet loss has > >>> long been a point of contention in TCP congestion control. This has > >>> partly been resolved, as it has become increasingly evident that delay > >>> based methods are needed to facilitate modern interactive web > >>> applications. However, what has not been resolved is what control > >>> should be used, with the two candidates being the congestion window > >>> and the pacing rate. BBR is a new delay based congestion control > >>> algorithm that uses a pacing rate as its primary control and the > >>> congestion window as a secondary control. We propose that a congestion > >>> window first algorithm might give more desirable performance > >>> characteristics in situations where latency must be minimized even at > >>> the expense of some loss in throughput. To evaluate this hypothesis we > >>> introduce a new congestion control algorithm called TCP D*, which is a > >>> congestion window first algorithm that adopts BBR's approach of > >>> maximizing delivery rate while minimizing latency. In this paper, we > >>> discuss the key features of this algorithm, discuss the differences > >>> and similarity to BBR, and present some preliminary results based on a > >>> real implementation." > >>> > >>> > >>> > >>> > >>> -- > >>> "For a successful technology, reality must take precedence over public > >>> relations, for Mother Nature cannot be fooled" - Richard Feynman > >>> > >>> dave@taht.net <Dave T?ht> CTO, TekLibre, LLC Tel: 1-831-435-0729 > >> > >> _______________________________________________ > >> Make-wifi-fast mailing list > >> Make-wifi-fast@lists.bufferbloat.net > >> https://lists.bufferbloat.net/listinfo/make-wifi-fast > > > > > > This electronic communication and the information and any files transmitted with it, or attached to it, are confidential and are intended solely for the use of the individual or entity to whom it is addressed and may contain information that is confidential, legally privileged, protected by privacy laws, or otherwise restricted from disclosure to anyone else. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, you are hereby notified that any use, copying, distributing, dissemination, forwarding, printing, or copying of this e-mail is strictly prohibited. If you received this e-mail in error, please return the e-mail to the sender, delete it from your computer, and destroy any printed copy of it. > > > > -- > "For a successful technology, reality must take precedence over public > relations, for Mother Nature cannot be fooled" - Richard Feynman > > dave@taht.net <Dave T?ht> CTO, TekLibre, LLC Tel: 1-831-435-0729 [ Attachment, skipping... ] [ Attachment, skipping... ] [ Attachment, skipping... ] [ Attachment, skipping... ] > _______________________________________________ > Ecn-sane mailing list > Ecn-sane@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/ecn-sane > -- Rod Grimes rgrimes@freebsd.org ^ permalink raw reply [flat|nested] 10+ messages in thread
* [Flent-users] Re: [Ecn-sane] [Make-wifi-fast] D* tcp looks pretty good, on paper 2021-01-08 14:35 ` [Flent-users] Re: [Ecn-sane] " Rodney W. Grimes @ 2021-01-08 17:52 ` Bob McMahon 0 siblings, 0 replies; 10+ messages in thread From: Bob McMahon @ 2021-01-08 17:52 UTC (permalink / raw) To: Rodney W. Grimes Cc: Dave Taht, ghosal, BBR Development, Taran Lynn, Make-Wifi-fast, ECN-Sane, bloat, codel, flent-users [-- Attachment #1.1: Type: text/plain, Size: 17510 bytes --] For that run it was two nodes each using 8 core (16 hyperthreads) systems running Fedora 30 each with a spectracom GPS disciplined OCXO over pcie. The two nodes are connected via a single 10G switch with 10G copper. I use this rig as part of iperf 2 development. I haven't published any results with the raspberry pie as the PTP grandmaster. I just want to mention it because most people can't afford the spectracom based systems. We have many runs around WiFi with competitive traffic same stack, air compete, AIFS disadvantaged, etc. All these results are internal use only. Also, a side note and a reminder by Jaffe written in 1981, that flow control power is not decentralizeble per the below <https://ieeexplore.ieee.org/document/1095152>. "On the assumption that communication links behave like M/M/1 servers it is shown that no "decentralized flow control algorithm" can maximize network power. Power has been suggested in the literature as a network performance objective. It is also shown that no objective based only on the users' throughputs and average delay is decentralizable. Finally, a restricted class of algorithms cannot even approximate power. Bob On Fri, Jan 8, 2021 at 6:35 AM Rodney W. Grimes <4bone@gndrsh.dnsmgr.net> wrote: > > This is through one of the last remaining cerowrt boxes in the world, > > running fq_codel. tcp-davis takes about a 20% single stream throughput > > hit vs bbr. > > > > I note, that I don't care one whit about throughput anymore. I care > > that nothing, NOTHING messes up my videoconference... > > IMHO it is a fools errand to place all priorty on one of throughput > or delay, but it is reasonable to slightly bias the situation to > defer a bit over throughput if a stable lower delay is gained. The > lost of some throughput can often be made up with additional capacity, > but nothing can increase the speed of light. > > > and thus the tcp-rtt stats attached for davis are pleasing. > > A questions/comment inline below about this data. > > > > > On Thu, Jan 7, 2021 at 12:26 PM Bob McMahon <bob.mcmahon@broadcom.com> > wrote: > > > > > > FYI, one can try this out using iperf 2.1 with --trip-times. This > gives end/end delay at the application level. One can use --trip-times when > clocks > > > are sync'd to get the write to read latencies which are the latencies > at the application level. > > > > > > Note: I set up a Raspberry Pi 4 with a GPS hat from ubutronics for > solderless pulse per second. Then configured it as a PTP grandmaster. > This cost me around $200. > > Ok, so that is the clock source node, could we get a better description of > the network topology and end node hardware? > > > > I also added support for a very crude --near-congestion option that > paces the writes based upon the weight of the RTT. The tcp_info struct is > sampled and available > > > for other experiments though one would have to modify the source a > bit. This current technique used by iperf 2.1 is designed for test networks > only where all > > > traffic is under script control. We've had too many people measuring > bloat as latency. We really need separate measurements between the two > phenomena, > > > bloat vs latency, because they require different eng actions for a > semiconductor supplier. > > > > > > Below are examples over a 10G link, first with no write pacing then > with it. The server output, shown first, has the latency data (as well as > the net power > > > and little's law calculation.) (Note: use --histograms for to get > full distributions.) > > Is this network a 3 node physical dumb-bell, or is this in Netem or is > this something more complicated? > What is the inherient delay path of this network? Aka, what is D in the > BDP, given the near saturation and the small window my guess is this is a > simple 3 node dumb bell, but would like confirmation of that. > > > > > > > No write pacing > > > > > > [rjmcmahon@localhost iperf2-code]$ src/iperf -s -i 1 -e > > > ------------------------------------------------------------ > > > Server listening on TCP port 5001 with pid 24568 > > > Read buffer size: 128 KByte (Dist bin width=16.0 KByte) > > > TCP window size: 85.3 KByte (default) > > > ------------------------------------------------------------ > > > [ 1] local 192.168.1.10%enp2s0 port 5001 connected with 192.168.1.62 > port 50056 (MSS=1448) (trip-times) (sock=4) (peer 2.1.0-rc) on 2021-01-07 > 12:11:04 (PST) > > > [ ID] Interval Transfer Bandwidth Burst Latency > avg/min/max/stdev (cnt/size) inP NetPwr Reads=Dist > > > [ 1] 0.00-1.00 sec 1.09 GBytes 9.34 Gbits/sec > 2.959/1.180/3.681/0.388 ms (8905/131072) 3.31 MByte 394522 > 18480=2459:2580:2475:2354:2203:2192:1974:2243 > > > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec > 2.993/2.302/3.703/0.359 ms (8978/131072) 3.36 MByte 393209 > 19482=2526:2850:3102:2622:2344:2297:1867:1874 > > > [ 1] 2.00-3.00 sec 1.10 GBytes 9.42 Gbits/sec > 3.010/2.302/3.692/0.347 ms (8978/131085) 3.38 MByte 391047 > 19387=2563:2757:2928:2708:2432:2244:1829:1926 > > > [ 1] 3.00-4.00 sec 1.10 GBytes 9.41 Gbits/sec > 3.009/2.301/3.668/0.348 ms (8979/131060) 3.38 MByte 391094 > 18821=2456:2585:2660:2545:2270:2239:1906:2160 > > > [ 1] 4.00-5.00 sec 1.10 GBytes 9.42 Gbits/sec > 2.985/2.299/3.696/0.359 ms (8979/131070) 3.35 MByte 394295 > 19441=2509:2886:2959:2728:2336:2200:1971:1852 > > > [ 1] 5.00-6.00 sec 1.10 GBytes 9.41 Gbits/sec > 2.977/2.258/3.671/0.363 ms (8978/131082) 3.34 MByte 395352 > 18509=2352:2602:2464:2380:2263:2142:2095:2211 > > > [ 1] 6.00-7.00 sec 1.10 GBytes 9.41 Gbits/sec > 2.980/2.290/3.680/0.363 ms (8978/131072) 3.34 MByte 394873 > 18522=2407:2499:2565:2334:2213:2268:1999:2237 > > > [ 1] 7.00-8.00 sec 1.10 GBytes 9.42 Gbits/sec > 2.980/2.253/3.702/0.362 ms (8979/131073) 3.35 MByte 394972 > 18615=2427:2592:2493:2460:2281:2057:2062:2243 > > > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec > 2.976/2.277/3.663/0.364 ms (8979/131065) 3.34 MByte 395443 > 18632=2338:2615:2647:2351:2192:2317:2063:2109 > > > [ 1] 9.00-10.00 sec 1.10 GBytes 9.41 Gbits/sec > 2.976/2.293/3.690/0.366 ms (8978/131076) 3.34 MByte 395416 > 18428=2281:2622:2497:2275:2178:2253:2129:2193 > > > [ 1] 0.00-10.00 sec 11.0 GBytes 9.41 Gbits/sec > 2.984/1.180/3.703/0.362 ms (89736/131072) 3.35 MByte 394014 > 188367=24320:26609:26793:24757:22712:22211:19916:21049 > > > > > > > > > [rjmcmahon@localhost iperf2-code]src/iperf -c 192.168.1.10 > --trip-times -i 1 -e > > > ------------------------------------------------------------ > > > Client connecting to 192.168.1.10, TCP port 5001 with pid 18961 (1 > flows) > > > Write buffer size: 131072 Byte > > > TCP window size: 85.0 KByte (default) > > > ------------------------------------------------------------ > > > [ 1] local 192.168.1.62%enp2s0 port 50056 connected with 192.168.1.10 > port 5001 (MSS=1448) (trip-times) (sock=3) (ct=0.41 ms) on 2021-01-07 > 12:11:04 (PST) > > > [ ID] Interval Transfer Bandwidth Write/Err Rtry > Cwnd/RTT NetPwr > > > [ 1] 0.00-1.00 sec 1.09 GBytes 9.37 Gbits/sec 8937/0 0 > 1508K/1099 us 1065750 > > > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 > 1508K/1087 us 1082218 > > > [ 1] 2.00-3.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 > 1508K/1081 us 1088225 > > > [ 1] 3.00-4.00 sec 1.10 GBytes 9.42 Gbits/sec 8984/0 0 > 1508K/1085 us 1085300 > > > [ 1] 4.00-5.00 sec 1.10 GBytes 9.42 Gbits/sec 8980/0 0 > 1508K/1105 us 1065182 > > > [ 1] 5.00-6.00 sec 1.10 GBytes 9.41 Gbits/sec 8975/0 0 > 1582K/1100 us 1069428 > > > [ 1] 6.00-7.00 sec 1.10 GBytes 9.42 Gbits/sec 8979/0 0 > 1582K/1121 us 1049862 > > > [ 1] 7.00-8.00 sec 1.10 GBytes 9.41 Gbits/sec 8976/0 0 > 1582K/1133 us 1038396 > > > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 8978/0 0 > 1582K/1115 us 1055394 > > > [ 1] 9.00-10.00 sec 1.10 GBytes 9.42 Gbits/sec 8986/0 0 > 1582K/1122 us 1049744 > > > [ 1] 0.00-10.00 sec 11.0 GBytes 9.41 Gbits/sec 89748/0 0 > 1582K/1122 us 1048294 > > > > > > > > > With write pacing > > > > > > [rjmcmahon@localhost iperf2-code]$ src/iperf -s -i 1 -e > > > ------------------------------------------------------------ > > > Server listening on TCP port 5001 with pid 24702 > > > Read buffer size: 128 KByte (Dist bin width=16.0 KByte) > > > TCP window size: 85.3 KByte (default) > > > ------------------------------------------------------------ > > > [ 1] local 192.168.1.10%enp2s0 port 5001 connected with 192.168.1.62 > port 50072 (MSS=1448) (trip-times) (sock=4) (peer 2.1.0-rc) on 2021-01-07 > 12:14:59 (PST) > > > [ ID] Interval Transfer Bandwidth Burst Latency > avg/min/max/stdev (cnt/size) inP NetPwr Reads=Dist > > > [ 1] 0.00-1.00 sec 1.08 GBytes 9.31 Gbits/sec > 0.401/0.193/2.682/0.168 ms (8876/131084) 456 KByte 2904347 > 19868=3296:2404:2508:2797:3559:1778:1551:1975 > > > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec > 0.400/0.219/0.627/0.053 ms (8971/131071) 460 KByte 2937822 > 19117=3069:2267:2307:2510:3029:1824:1683:2428 > > > [ 1] 2.00-3.00 sec 1.09 GBytes 9.39 Gbits/sec > 0.374/0.193/0.541/0.055 ms (8958/131060) 428 KByte 3143030 > 18942=2846:2423:2304:2417:2927:1831:1856:2338 > > > [ 1] 3.00-4.00 sec 1.09 GBytes 9.39 Gbits/sec > 0.385/0.190/0.664/0.070 ms (8952/131072) 441 KByte 3050401 > 19248=3041:2175:2343:2749:3320:1805:1526:2289 > > > [ 1] 4.00-5.00 sec 1.09 GBytes 9.40 Gbits/sec > 0.380/0.197/0.546/0.057 ms (8965/131075) 436 KByte 3095915 > 19959=3321:2398:2551:2738:3500:1840:1532:2079 > > > [ 1] 5.00-6.00 sec 1.09 GBytes 9.39 Gbits/sec > 0.369/0.198/0.536/0.051 ms (8956/131072) 423 KByte 3177431 > 21060=3627:2456:2886:3189:4246:1813:1190:1653 > > > [ 1] 6.00-7.00 sec 1.09 GBytes 9.39 Gbits/sec > 0.380/0.202/0.562/0.054 ms (8959/131077) 436 KByte 3086914 > 19263=3044:2338:2424:2505:3155:1809:1636:2352 > > > [ 1] 7.00-8.00 sec 1.09 GBytes 9.40 Gbits/sec > 0.376/0.198/0.541/0.053 ms (8965/131061) 432 KByte 3122495 > 19137=3079:2303:2340:2455:3017:1822:1683:2438 > > > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec > 0.381/0.208/0.576/0.054 ms (8974/131073) 438 KByte 3083767 > 19162=3050:2269:2392:2486:3019:1891:1667:2388 > > > [ 1] 9.00-10.00 sec 1.09 GBytes 9.40 Gbits/sec > 0.371/0.194/0.582/0.057 ms (8964/131070) 425 KByte 3169244 > 19143=3006:2411:2303:2462:3067:1744:1760:2390 > > > [ 1] 0.00-10.00 sec 10.9 GBytes 9.39 Gbits/sec > 0.382/0.190/2.682/0.076 ms (89544/131072) 437 KByte 3074913 > 194908=31380:23444:24362:26308:32839:18161:16084:22330 > > > > > > > > > [rjmcmahon@localhost iperf2-code]$ src/iperf -c 192.168.1.10 > --near-congestion=0.05 --trip-times -i 1 -e > > > ------------------------------------------------------------ > > > Client connecting to 192.168.1.10, TCP port 5001 with pid 19320 (1 > flows) > > > Write buffer size: 131072 Byte > > > TCP near-congestion delay weight set to 0.0500 > > > TCP window size: 85.0 KByte (default) > > > ------------------------------------------------------------ > > > [ 1] local 192.168.1.62%enp2s0 port 50072 connected with 192.168.1.10 > port 5001 (MSS=1448) (trip-times) (sock=3) (ct=0.40 ms) on 2021-01-07 > 12:14:59 (PST) > > > [ ID] Interval Transfer Bandwidth Write/Err Rtry > Cwnd/RTT NetPwr > > > [ 1] 0.00-1.00 sec 1.08 GBytes 9.31 Gbits/sec 8881/0 0 > 1135K/373 us 3120427 > > > [ 1] 1.00-2.00 sec 1.10 GBytes 9.41 Gbits/sec 8971/0 0 > 1135K/391 us 3007281 > > > [ 1] 2.00-3.00 sec 1.09 GBytes 9.39 Gbits/sec 8958/0 0 > 1135K/331 us 3547260 > > > [ 1] 3.00-4.00 sec 1.09 GBytes 9.39 Gbits/sec 8952/0 0 > 1135K/288 us 4074155 > > > [ 1] 4.00-5.00 sec 1.09 GBytes 9.40 Gbits/sec 8965/0 0 > 1135K/301 us 3903855 > > > [ 1] 5.00-6.00 sec 1.09 GBytes 9.39 Gbits/sec 8955/0 0 > 1135K/414 us 2835144 > > > [ 1] 6.00-7.00 sec 1.09 GBytes 9.40 Gbits/sec 8961/0 0 > 1135K/470 us 2499013 > > > [ 1] 7.00-8.00 sec 1.09 GBytes 9.40 Gbits/sec 8964/0 0 > 1135K/350 us 3356941 > > > [ 1] 8.00-9.00 sec 1.10 GBytes 9.41 Gbits/sec 8973/0 0 > 1135K/472 us 2491756 > > > [ 1] 9.00-10.00 sec 1.09 GBytes 9.40 Gbits/sec 8964/0 0 > 1135K/402 us 2922710 > > > [ 1] 0.00-10.00 sec 10.9 GBytes 9.39 Gbits/sec 89547/0 0 > 1135K/402 us 2919642 > > > > > > Bob > > > > > > > > > On Thu, Jan 7, 2021 at 11:22 AM Taran Lynn via Make-wifi-fast < > make-wifi-fast@lists.bufferbloat.net> wrote: > > >> > > >> The source can be found at https://github.com/lambda-11235/tcp_davis > . > > >> > > >> The code mentioned in the paper can be found under the tag > "arxiv_2020". The current master branch has an additional stable mode that > I was testing out. > > >> > > >> > > >> On Thu, Jan 7, 2021 at 10:35 AM Dave Taht <dave.taht@gmail.com> > wrote: > > >>> > > >>> See: https://arxiv.org/pdf/2012.14996.pdf > > >>> > > >>> Things I really like: > > >>> > > >>> * they used flent > > >>> * Using "variance" as the principal signal. This is essentially one > of > > >>> the great unpublished and unanalyzed improvements on the minstrel > > >>> algorithm as well > > >>> * Conventional ecn response > > >>> * outperforms bbr on variable links > > >>> > > >>> Only negative so far is I haven't found any published source to it. > :( > > >>> > > >>> Otherwise a very promising start to a year. > > >>> > > >>> "The choice of feedback mechanism between delay and packet loss has > > >>> long been a point of contention in TCP congestion control. This has > > >>> partly been resolved, as it has become increasingly evident that > delay > > >>> based methods are needed to facilitate modern interactive web > > >>> applications. However, what has not been resolved is what control > > >>> should be used, with the two candidates being the congestion window > > >>> and the pacing rate. BBR is a new delay based congestion control > > >>> algorithm that uses a pacing rate as its primary control and the > > >>> congestion window as a secondary control. We propose that a > congestion > > >>> window first algorithm might give more desirable performance > > >>> characteristics in situations where latency must be minimized even at > > >>> the expense of some loss in throughput. To evaluate this hypothesis > we > > >>> introduce a new congestion control algorithm called TCP D*, which is > a > > >>> congestion window first algorithm that adopts BBR's approach of > > >>> maximizing delivery rate while minimizing latency. In this paper, we > > >>> discuss the key features of this algorithm, discuss the differences > > >>> and similarity to BBR, and present some preliminary results based on > a > > >>> real implementation." > > >>> > > >>> > > >>> > > >>> > > >>> -- > > >>> "For a successful technology, reality must take precedence over > public > > >>> relations, for Mother Nature cannot be fooled" - Richard Feynman > > >>> > > >>> dave@taht.net <Dave T?ht> CTO, TekLibre, LLC Tel: 1-831-435-0729 > > >> > > >> _______________________________________________ > > >> Make-wifi-fast mailing list > > >> Make-wifi-fast@lists.bufferbloat.net > > >> https://lists.bufferbloat.net/listinfo/make-wifi-fast > > > > > > > > > This electronic communication and the information and any files > transmitted with it, or attached to it, are confidential and are intended > solely for the use of the individual or entity to whom it is addressed and > may contain information that is confidential, legally privileged, protected > by privacy laws, or otherwise restricted from disclosure to anyone else. If > you are not the intended recipient or the person responsible for delivering > the e-mail to the intended recipient, you are hereby notified that any use, > copying, distributing, dissemination, forwarding, printing, or copying of > this e-mail is strictly prohibited. If you received this e-mail in error, > please return the e-mail to the sender, delete it from your computer, and > destroy any printed copy of it. > > > > > > > > -- > > "For a successful technology, reality must take precedence over public > > relations, for Mother Nature cannot be fooled" - Richard Feynman > > > > dave@taht.net <Dave T?ht> CTO, TekLibre, LLC Tel: 1-831-435-0729 > > [ Attachment, skipping... ] > > [ Attachment, skipping... ] > > [ Attachment, skipping... ] > > [ Attachment, skipping... ] > > > _______________________________________________ > > Ecn-sane mailing list > > Ecn-sane@lists.bufferbloat.net > > https://lists.bufferbloat.net/listinfo/ecn-sane > > > -- > Rod Grimes > rgrimes@freebsd.org > -- This electronic communication and the information and any files transmitted with it, or attached to it, are confidential and are intended solely for the use of the individual or entity to whom it is addressed and may contain information that is confidential, legally privileged, protected by privacy laws, or otherwise restricted from disclosure to anyone else. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, you are hereby notified that any use, copying, distributing, dissemination, forwarding, printing, or copying of this e-mail is strictly prohibited. If you received this e-mail in error, please return the e-mail to the sender, delete it from your computer, and destroy any printed copy of it. [-- Attachment #1.2: Type: text/html, Size: 21363 bytes --] [-- Attachment #2: S/MIME Cryptographic Signature --] [-- Type: application/pkcs7-signature, Size: 4163 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
* [Flent-users] Re: [bbr-dev] D* tcp looks pretty good, on paper 2021-01-07 18:35 [Flent-users] D* tcp looks pretty good, on paper Dave Taht 2021-01-07 19:20 ` [Flent-users] " Taran Lynn @ 2021-01-08 15:38 ` Neal Cardwell 2021-01-08 16:13 ` [Flent-users] Re: [Make-wifi-fast] " Jonathan Morton 1 sibling, 1 reply; 10+ messages in thread From: Neal Cardwell @ 2021-01-08 15:38 UTC (permalink / raw) To: Dave Taht Cc: bloat, codel, ECN-Sane, Make-Wifi-fast, flent-users, BBR Development, ghosal, tflynn [-- Attachment #1: Type: text/plain, Size: 1592 bytes --] On Thu, Jan 7, 2021 at 1:35 PM Dave Taht <dave.taht@gmail.com> wrote: > See: https://arxiv.org/pdf/2012.14996.pdf Thanks for the link! > > Things I really like: > > * they used flent > * Using "variance" as the principal signal. This is essentially one of > the great unpublished and unanalyzed improvements on the minstrel > algorithm as well > * Conventional ecn response > * outperforms bbr on variable links > What did you have in mind by "variable links" here? (I did not see that term in the paper.) Rather than characterizing the algorithm as using "variance" as the principal signal, my sense is that the estimated BDP is the primary signal, and the algorithm uses variance as a secondary signal to adapt the gain. I would be interested to hear how the algorithm performs in real-world paths with high degrees of aggregation and RTT variance, including wifi, cellular, and 10Gbps+ Ethernet LANs. The paper mentions "TCP D* sets the window to its estimated BDP," and our experience is that setting cwnd to the estimated BDP produces unusably low throughput over these kinds of paths. In these paths the min_rtt is very different from the typical RTT, so setting the cwnd purely using the min_rtt can lead to very significant underutilization: https://datatracker.ietf.org/meeting/101/materials/slides-101-iccrg-an-update-on-bbr-work-at-google-00#page=5 Another interesting aspect is that it seems completely agnostic to packet losses. It would be interesting to see how the algorithm behaves in shallow or mid-sized buffers with a highly dynamic mix of traffic. best, neal [-- Attachment #2: Type: text/html, Size: 2504 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
* [Flent-users] Re: [Make-wifi-fast] [bbr-dev] D* tcp looks pretty good, on paper 2021-01-08 15:38 ` [Flent-users] Re: [bbr-dev] " Neal Cardwell @ 2021-01-08 16:13 ` Jonathan Morton 2021-01-08 16:24 ` Bryson Richard 0 siblings, 1 reply; 10+ messages in thread From: Jonathan Morton @ 2021-01-08 16:13 UTC (permalink / raw) To: Neal Cardwell Cc: Dave Taht, ghosal, BBR Development, tflynn, Make-Wifi-fast, ECN-Sane, bloat, codel, flent-users > On 8 Jan, 2021, at 5:38 pm, Neal Cardwell via Make-wifi-fast <make-wifi-fast@lists.bufferbloat.net> wrote: > > What did you have in mind by "variable links" here? (I did not see that term in the paper.) Wifi and LTE tend to vary their link characteristics a lot over time. - Jonathan Morton ^ permalink raw reply [flat|nested] 10+ messages in thread
* [Flent-users] Re: [Make-wifi-fast] [bbr-dev] D* tcp looks pretty good, on paper 2021-01-08 16:13 ` [Flent-users] Re: [Make-wifi-fast] " Jonathan Morton @ 2021-01-08 16:24 ` Bryson Richard 0 siblings, 0 replies; 10+ messages in thread From: Bryson Richard @ 2021-01-08 16:24 UTC (permalink / raw) To: Jonathan Morton Cc: Neal Cardwell, Dave Taht, ghosal, BBR Development, tflynn, Make-Wifi-fast, ECN-Sane, bloat, codel, flent-users [-- Attachment #1: Type: text/plain, Size: 794 bytes --] STOP ALL NOW AND FOREVER On Fri, Jan 8, 2021, 10:13 AM Jonathan Morton <chromatix99@gmail.com> wrote: > > On 8 Jan, 2021, at 5:38 pm, Neal Cardwell via Make-wifi-fast < > make-wifi-fast@lists.bufferbloat.net> wrote: > > > > What did you have in mind by "variable links" here? (I did not see that > term in the paper.) > > Wifi and LTE tend to vary their link characteristics a lot over time. > > - Jonathan Morton > > -- > You received this message because you are subscribed to the Google Groups > "BBR Development" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to bbr-dev+unsubscribe@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/bbr-dev/98CABC94-0E85-4981-85D2-52C7F02F3B9E%40gmail.com > . > [-- Attachment #2: Type: text/html, Size: 1451 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2021-01-08 17:52 UTC | newest] Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-01-07 18:35 [Flent-users] D* tcp looks pretty good, on paper Dave Taht 2021-01-07 19:20 ` [Flent-users] " Taran Lynn 2021-01-07 20:25 ` [Flent-users] Re: [Make-wifi-fast] " Bob McMahon 2021-01-07 21:41 ` Dave Taht 2021-01-07 22:22 ` Bob McMahon 2021-01-08 14:35 ` [Flent-users] Re: [Ecn-sane] " Rodney W. Grimes 2021-01-08 17:52 ` Bob McMahon 2021-01-08 15:38 ` [Flent-users] Re: [bbr-dev] " Neal Cardwell 2021-01-08 16:13 ` [Flent-users] Re: [Make-wifi-fast] " Jonathan Morton 2021-01-08 16:24 ` Bryson Richard
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