[Bloat] dslreports bufferbloat tests

[Jonathan Morton]

> On 7 Apr, 2016, at 05:06, jb <justin at dslr.net> wrote:
> 
> But am I just looking for "ECN capable" flags originating from a given
> public IP?
> or am I filtering just for CE marks (11), indicating there was some
> active queue management actually going on -- and only that would be
> worth mentioning?

The latter.  CE marks indicate that the bottleneck router is using AQM with ECN support.  ECT marks only indicate that the traffic supports ECN, not that it’s actually doing any good.

Beware however that one or two ISPs are known to set CE on all traffic, indiscriminately.  You should be able to detect this by looking for CE on SYN packets, which should never be there (ECN negotiation is initiated through TCP flags, not the IP TOS byte).  Report this to the user as a problem.

 - Jonathan Morton