[techtalk] Download throttling?

[Conor Daly]

On Sun, Sep 03, 2000 at 01:31:45PM +0000 or so it is rumoured hereabouts, 
jenn at simegen.com thought:
> Mary Gardiner wrote:
> 
> > Well we have a 56K. I actually consider this fairly good since my previous
> > experience with modems and the net was in regional Austrlia sharing a 28.8
> > with the rest of the school... :)
> 
> I'm in urban Australia. :) Melbourne, actually.
> 
> 
> > > Apparently in Linux 2.2 or later, 'quality of service and fair
> > > scheduling', under network options. All the facilities are
> > > implemented by that. The IProute package is used to configure it.
> > > And, to quote him, 'Good luck figuring out how'.
> > 
> > Oops. My flatmates regarded this as a challenge...
> 
> Good! Get them to document their results? Please? :)
> 
> 

Just had a look at some of the documentation...  Informative?  Hah!

Just half a page on traffic control but it raises some questions.  I'm
using a similar setup:
486/66 firewall/router/dial-on-demand with ipmasq for the net with clients
and server behind it.  

Now, one can set up a tunnel from a source IP to a destination 
IP through a device (real or virtual) and limit the bandwith, burst size
and queue size.  Queueing cannot be implemented on a virtual device so the
virtual must be mapped to a real device.  So, the questions arise...

1.  Can multiple virtual devices map to a single real device (eg ppp0)?

2.  If ipmasq changes all packets to an outbound ip address on the way to
ppp0, do you end up with all traffic going down a single tunnel?

3.  Do you end up having to do forwarding to different tunnels for each
client / protocol first and then ip masq the tunnels on their way to ppp0
(maybe bind the tunnels to eth0 rather than to ppp0)?

4.  Can you adjust the bandwidth parameters on the fly or only at setup of
the tunnel?  Can a single client on-line get the benefit of the full
bandwidth and get throttled back when another user goes on-line?

5.  Does all this mean an 'orrible mess of a routing table?

-- 
Conor Daly <conor.daly at oceanfree.net>

Domestic Sysadmin :-)