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

[Mike Gabriel]

Hi John,

On Di 21 Feb 2012 10:43:03 CET "John A. Sullivan III" wrote:

> On Tue, 2012-02-21 at 10:11 +0100, Jan Engelhardt wrote:
>> 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.
> Thanks.  I suppose we are saying the same thing in a different way.  I
> am saying we cannot rely upon libssh setting a TOS bit but we do need to
> do something within X2Go to allow admins to distinguish the traffic.  We
> need some method embedded in the traffic.  The obvious choice is to use
> either TOS bits or DSCP but we do need to set something - John

I guess we do not have the urgency here on the coders side, currently.  
Just a gut feeling. Best would be to directly come up with a patch or  
hire someone who comes up with a patch. Then inclusion in mainstream  
X2Go (Client) may become _very_ likely.

Greets,
Mike




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