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Re: CBQ question
On Mon, Sep 04, 2000 at 07:52:28PM +0200, Idan Sofer wrote:
> Hello.
>
> I have a linux system(2.2.16) connected to the internet using dial-up
> connection, And another two win98 systems connected to the linux system
> via ethernet.
>
> The linux machine is masquerading tcp packets from the win98 boxes to the
> internet. problem is that if the the linux machine is downloading
> something from a fast site(3-4kb/s), the win98 machines find the bandwidth
> very narrow.
.and it never happens the other way around? (i.e., windows
downloading fast and Linux slowly).
There can be a problem when you are downloading from two different
sites with different RTTs (round trip times - the delay to that site
and back). TCP favors low RTT connections and if the difference is
big enough the high RTT connection is starved.
I'm not sure if that is what you are experiencing, though. Can you
recreate the problem on *one* (Linux) machine?
There can be other reasons for this behavior, but it's hard to
tell.
Anyway, controlling the bandwidth a TCP connection uses in the
direction from the ISP to your home can only be done by controlling
the rate of ACK packets sent by your machine. CBQ or any queueing
discipline won't do the trick and, in fact, I'm not aware of any
free software that regulates bandwidth in the reverse direction.
Of course, you can always modify the source for the ftp program so
that it reads data from the socket at the desired rate. TCP flow
control will limit the sender from overflowing the receiver's
buffers so that should work.
--
Nimrod.
http://www.geocities.com/rodd_27
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