Re: how much traffic does an unthrottled middleman draw on 100 MBit/s?

[Roger Dingledine <arma@xxxxxxx>]

On Wed, Mar 21, 2007 at 05:19:35PM +0100, Eugen Leitl wrote:
> shrek2 is unthrottled, and the CPU and memory footprint is in
> low 2-10%, while the network throughput is around 3-5% 
> of a 100 MBit line (the switch has a Java applet which
> displays traffic bar over the ports). It doesn't seem to be getting any more 
> lately.
> 
> Does it take a long time until the server gets more traffic?
> I'd rather not go away on a long weekend, and come back to 4 days
> worth of full 100 MBit/s pipe.

It's unlikely to go past about 25Mbps sustained, even if there is no rate
limiting  -- the load balancing over the Tor network isn't good enough
to allocate more than that to you, because there are lots of slower Tor
servers that cause bottlenecks.

> > This adds up to a lot of bytes per month. :) And it looks like it's rate
> > limited by the default 3MB/6MB rate limiting, so it could be even higher
> 
> So the total hardcoded limit is 9 MByte/s?

The default BandwidthRate is 3 MB, and the default BandwidthBurst is 6 MB.

shrek2 appears to be using these defaults currently.

So it won't go past 24Mbps sustained (or 48Mbps if you're one of those
people who adds incoming traffic and outgoing traffic and calls that
the bandwidth use.)

(If you're using Tor 0.1.1.x, which you are, the BandwidthRate doesn't
do any rate limit on outgoing bytes -- so your directory writes could
exceed 24Mbps out. You should move to 0.1.2.12-rc or later if you don't
like this.)

Hope this helps,
--Roger