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

[Jan Engelhardt]

On Tuesday 2012-02-21 09:43, John A. Sullivan III wrote:

>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.

That too. All these reasons is why TOS is not a reliable characteristic 
to determine the question of bulk-or-interactive.

>PS - out of curiosity, now does one set the QoS type in OpenSSH?

ssh -o IPQoS={bulk|interactive|0x12345} ...

ssh -L 2000:localhost:22 foohost &
rsync -HPave 'ssh -p 2000' bulky.iso localhost:

and in fact, wouldn't the output `ls -Rl /` in an interactive shell also 
best be count as bulk...