[tor-talk] Calculation of Bandwidth weights

[Roger Dingledine]

On Thu, Jun 19, 2014 at 02:58:12PM +0900, saurav dahal wrote:
> Hello,
> 
> I studied about computing bandwidth from
> 
> https://gitweb.torproject.org/torspec.git/blob/HEAD:/dir-spec.txt#l2157
> 
> But I could not understand the procedure. Can anyone please explain me
> about calculating the bandwidth weights in simple way.

The bandwidth weight in the consensus is calculated in a simple way:
it's the median of the bandwidth weights in each vote.

So now you should ask how each directory authority calculates the weight
it will use for its vote.

These two documents are good starts there:
https://gitweb.torproject.org/torflow.git/blob/HEAD:/NetworkScanners/BwAuthority/README.BwAuthorities
https://gitweb.torproject.org/torflow.git/blob/HEAD:/NetworkScanners/BwAuthority/README.spec.txt
and for distant history, you might like Mike's hotpets paper:
https://blog.torproject.org/blog/torflow-node-capacity-integrity-and-reliability-measurements-hotpets

Or if you want the simpler answer: "Sorry, there is no simple way to
explain it. It is all a pile of hacks stacked on top of each other. It's
a great research area where somebody could improve it. Please do."

--Roger