Also, Windows XP is still significantly in use in the Internet (unfortunately). On Thu, Mar 21, 2013 at 3:25 PM, Mikael Abrahamsson wrote: > On Thu, 21 Mar 2013, Oliver Hohlfeld wrote: > > In summary, the question on how much of a problem buffer bloat currently >> is cannot be fully answered and still requires further research. >> > > Buffer bloat is a problem on basically all access forms apart from ETTH. > Usually ETTH is produced using L2 or L3 switches with very small buffers (5 > ms or so), and policing is used instead of buffering for limiting service > rate. This means high speed TCP flows will sawtooth their performance over > time because of large amount of consecutive drops, meaning low bw > interactive flows are less impacted. > > So it's my belief that your measurements means most people don't actually > put congestion pressure on their accesses, thus the large buffers are > seldom used and you're not seeing buffering. Due to the fact TCP window scaling is off by default in Windows XP, the most a single TCP connection will have in flight on Windows XP is 64K bytes. This both limits the ability of a Windows XP system to saturate a link in the first place (thereby sometimes avoiding filling buffers at the bottleneck at all), and limits the amount of latency a single TCP connection will inflict. Every more modern TCP can easily fill any sized buffer given time with a single TCP connection. - Jim > > > -- > Mikael Abrahamsson email: swmike@swm.pp.se > > ______________________________**_________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/**listinfo/bloat >