On Tue, Oct 27, 2015 at 1:06 AM, Sebastian Moeller <moeller0@gmx.de> wrote:

> Hi Justin,
>
>
> On Oct 22, 2015, at 21:54 , Justin Uberti <juberti@google.com> wrote:
>
> > At present I'm not aware of any widely-deployed OS where an app can read
> the received ECN markings.
> >
> > iOS9 added support for this within the kernel, and it's used for TCP,
> but not exposed to userspace. There is an open Radar bug asking for this
> info to be exposed to userspace.
> >
> > FWIW, Chrome supports setting the DSCP markings if you set a magic
> parameter. But it's not on by default, mainly because we've never done the
> auditing necessary to ensure this doesn't randomly break in various
> dimly-lit parts of the internet.
>
>         Slightly related question, is this DSCP marking capability
> restricted to webrtc packets or is there a way to make chrome use
> (arbitrary) DSCP marks for all its packets? For exercising different
> priority banding schemes such an option would be perfect (say to test
> whether a aqm+qos system will allow snappy browsing even with heavy
> download/upload/bittorrent traffic in other priority bands; this test is
> especially interesting if all traffic sources can reside on the same host,
> as this is a quite common set-up in home networks, one computer that does
> everything concurrently and where the users still want a decent browsing
> experience).
>

The option that currently exists only works for WebRTC packets.