[tor-bugs] #12752 [Tor]: stem: Microdescript bandwidth considered unmeasured by default

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#12752: stem: Microdescript bandwidth considered unmeasured by default
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     Reporter:  asn     |      Owner:  atagar
         Type:  defect  |     Status:  new
     Priority:  normal  |  Milestone:
    Component:  Tor     |    Version:
   Resolution:          |   Keywords:
Actual Points:          |  Parent ID:
       Points:          |
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Changes (by atagar):

 * component:  Stem => Tor


Comment:

 Hi George, really sorry about the long delay. I'm still catching up on
 tickets. According to [https://gitweb.torproject.org/torspec.git/blob/HEAD
 :/dir-spec.txt#l1651 the dir-spec on this]...

  * 'Bandwidth=INT' is 'an estimate of the bandwidth of this relay' though
 it's really nebulous about what that means.
  * 'Measured=INT' is the vote of a bandwidth authority.
  * 'Unmeasured=1' has a specific meaning, which is that the
 'Bandwidth=INT' isn't based on three or more measurements.

 Stem's docs on this are...

 {{{
 :var int bandwidth: bandwidth claimed by the relay (in kb/s)
 :var int measured: bandwidth measured to be available by the relay
 :var bool is_unmeasured: bandwidth measurement isn't based on three or
 more
   measurements
 }}}

 On reading this again I suspect the behavior is as follows...

  * Votes from bandwidth authorities have 'Measured=' values.
  * These votes are transformed into 'Bandwidth=' for the consensus, with
 the 'Unmeasured=1' if it's not coming from 3 or more authorities (though
 the wording on this is vague enough that it could mean 3 or more samplings
 by a single authority).

 Either way, I'm happy to revise Stem if the dir-spec is clarified. Sending
 this over to the Tor component.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/12752#comment:1>
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