(1500 segment*2)/5ms=4.8Mb/sec minimum per connection. 20 connections is 96Mb/sec On May 21, 2017 8:08 AM, "cloneman" wrote: > thanks for the info. This is a possibility, as I have 5ms latency to their > servers with 50mbit of bandwidth. > > On May 21, 2017 8:49 AM, "Benjamin Cronce" wrote: > >> All current TCP implementations have a minimum window size of two >> segments. If you have 20 open connections, then the minimum bandwidth TCP >> will attempt to consume is (2 segments * 20 connection)/latency. If you >> have very low latency relative to your bandwidth, the sender will not >> respond to congestion. >> >> On Thu, Apr 6, 2017 at 9:47 PM, cloneman wrote: >> >>> Hi, >>> >>> Appologies in advance if this is the wrong place to ask, I haven't been >>> able to locate an official discussion board. >>> >>> I'm looking for any comments on Steam's game distribution download >>> system - specifically how it defeats any bufferbloat mitigation system I've >>> used. >>> >>> It seems to push past inbound policers, exceeding them by about 40%. >>> That is to say, if you police steam traffic to half of your line rate, >>> enough capacity will remain to avoid packet loss, latency, jitter etc. >>> Obviously this is too much bandwidth to reserve. >>> >>> Without any inbound control, you can expect very heavy packet loss and >>> jitter. With fq_codel or sfq and taking the usual recommended 15% off the >>> table, you get improved, but still unacceptable performance in your small >>> flows / ping etc. >>> >>> The behavior can be observed by downloading any free game on their >>> platform. I'm trying to figure out how they've accomplished this and how to >>> mitigate this behavior. It operates with 20 http connections >>> simultaneously, which is normally not an issue (multiple web downloads >>> perform well under fq_codel) >>> >>> Note: in my testing cable and vdsl below 100mbit were vulnerable to this >>> behavior, while fiber was immune. >>> >>> Basically there are edge cases on the internet that like to push too >>> many bytes down a line that is dropping or delaying packets. I would like >>> to see more discussion on this issue. >>> >>> I haven't tried tweaking any of the parameters / latency targets in >>> fq_codel. >>> >>> >>> _______________________________________________ >>> Bloat mailing list >>> Bloat@lists.bufferbloat.net >>> https://lists.bufferbloat.net/listinfo/bloat >>> >>> >>