[tor-relays] bandwidth authority algorithm is cracked

[starlight.2014q1 at binnacle.cx]

This helps tremendously--thank you.

For the most part then it appears the consensus
bandwidth values assigned to the relay here
are within reasonable expectation allowing
for the methodology.

Lately have been seeing fairly stable and
moderate number of 225k vs the local 495k
calculation.  Next time I see a wild swing
I'll pull the raw data and try to make sense
of it.  Will post if it's seems inexplicable
or as though a problem exists.



At 14:37 1/22/2014 -0500, Roger Dingledine wrote:
>On Wed, Jan 22, 2014 at 02:33:21PM -0500, Roger Dingledine wrote:
>> The consensus weight is computed using
>> a) the relay's self-advertised bandwidth in its descriptor:
>> https://gitweb.torproject.org/torspec.git/blob/HEAD:/dir-spec.txt#l389
>> b) the ratios of bandwidth weights for various types of relays:
>> https://gitweb.torproject.org/torspec.git/blob/HEAD:/dir-spec.txt#l2137
>> and
>> c) the result of the active measurements
>> from the bandwidth authorities:
>> 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
>
>I take it back -- the consensus weight is computed using 'a' and 'c'
>above, and then clients consider 'b' and the weights when 
>selecting
>relays.
>