[tor-bugs] #8494 [Core Tor/Tor]: Does MaxAdvertisedBandwidth do anything useful and if not, can we deprecate it?

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#8494: Does MaxAdvertisedBandwidth do anything useful and if not, can we deprecate
it?
-------------------------------------------------+-------------------------
 Reporter:  alphawolf                            |          Owner:  tom
     Type:  defect                               |         Status:  new
 Priority:  Low                                  |      Milestone:  Tor:
                                                 |  0.3.5.x-final
Component:  Core Tor/Tor                         |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  tor-spec, consensus, bandwidth,      |  Actual Points:
  MaxAdvertisedBandwidth tor-relay tor-dirauth   |
  needs-insight tor-bwauth                       |
Parent ID:                                       |         Points:
 Reviewer:                                       |        Sponsor:
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Comment (by juga):

 Bandwidth terms are different in `dir-spec.txt` and the code.
 If i'm not mistaken, what is called `bandwidthrate` [0] in the code when
 creating the descriptor, is called `bandwidth-avg` in `dir-spec.txt` [1].
 And it is calculated as the min(BandwidthRate, MaxAdvertisedBandwidth,
 RelayBandwidthRate) [2].
 If this is correct, the paragraph to add in `bandwidth-file-spec.txt`
 could be:

     sbws limits the relay's measured bandwidth to the bandwidth-avg
 advertised
     in the relay's descriptor, which is the minimum between BandwidthRate,
     MaxAdvertisedBandwidth and RelayBandwidthRate in the relay's
 configuration.

 Though probably the last sentence not needed.
 If Torflow is using also `bandwidth-avg`, then it could also be added in
 `bandwidth-file-spec.txt`:

     Torflow does not need to limit the relay's measured bandwidth since it
     partions relays to be measured by bandwidth-avg

 Is this correct?.

 [0] https://gitweb.torproject.org/tor.git/tree/src/or/router.c#n2370
 [1] https://gitweb.torproject.org/torspec.git/tree/dir-spec.txt#n427
 [2] https://gitweb.torproject.org/tor.git/tree/src/or/config.c#n1693

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/8494#comment:13>
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