[techtalk] Download throttling?

[Conor Daly]

On Mon, Sep 04, 2000 at 12:26:10PM +0200 or so it is rumoured hereabouts, 
Harald Welte thought:
> On Sun, Sep 03, 2000 at 09:47:29PM +0100, Conor Daly wrote:
> > 
> > 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...
> 
> ? I don't understand. Is the tunnel a necessity? You really want to do
> traffic shaping for a tunnel? Which kind of tunnel are You talking about
> L2TP? PPTP? IPsec? cipe?

Oh, I don't know...  I'm just going on what I read in the ip-tunnels.ps in
the ip-route doc directory.  My printer ran out of ink before I got to
print out the ip-cref.ps to read in bed so I may have missed out on
something there.  I presume, therefore, that the talk of traffic control
on tunnels is simply about er...  Controlling traffic on tunnels.:-)  I
mistook that to imply that tunnels were necessary for any form of traffic
control.  Will know better next time.
 
> 
> You don't need to set up a tunnel for the scheduling / queuing stuff.
> 
> > 1.  Can multiple virtual devices map to a single real device (eg ppp0)?
> 
> of course.
> 
> > 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)?
> 
> Please can 
> 
> > 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?
> 
> Why do You want to setup tunnels for Your bandwidth control? I still don't
> understand. 
Well, I didn't understand either! :-)

> 
> The usual setup is to have some classifier, which divides the packets into
> different classes (let's say a "slow" class and a priorized "fast" class)
> 
> You can then treat each of these classes differently, let's say use
> different scheduling algorithms for each of the classes
> 
> > 5.  Does all this mean an 'orrible mess of a routing table?
> 
> no. and You can have 255 routing tables in 2.2, and have ip rules select
> which routing table to use for which packet class.
> 

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

Domestic Sysadmin :-)