[X2Go-Dev] Traffic shaping nightmare - missing SSH TOS bits

[John A. Sullivan III]

On Tue, 2012-02-21 at 09:30 +0100, Jan Engelhardt wrote:
> On Tuesday 2012-02-21 07:05, John A. Sullivan III wrote:
> 
> >I've been working on a project to implement traffic shaping
> >to conform to 95th percentile billing including our X2Go virtual
> >desktops. One of the challenges is prioritizing the interactive X2Go
> >traffic (screen, keyboard, mouse) differently from bulk traffic like
> >local share transfers, printing, and possibly sound.  I thought this
> >would be trivial because of the SSH transport since SSH sets the
> >minimize-delay bit for interactive traffic and the maximize-throughput
> >bit for bulk transfers.
> 
> If a user has his own machine, he can of course do whatever he wants.
> Second, if he can pass options to ssh, he can set the QOS type
> arbitrarily, and even where that is not available for control, one
> can still cause the openssh client to use interactive TOS marking for
> bulk transfers, since secondary ssh channels (e.g. tunnels) do not
> pass up the TOS mark.
<snip>
However, Windows and Mac clients may not be using OpenSSH.  Users may
not have control over their X2Go Server configurations; they certainly
do not in our environment.  We do need a way to distinguish between bulk
and interactive traffic to ensure adequate performance in any bandwidth
constrained environment.  Thanks - John

PS - out of curiosity, now does one set the QoS type in OpenSSH? Several
minutes of searching has not given me an answer.  That's far from an
exhaustive search but, if someone knows off hand, it would be helpful.
Thanks - John