[tor-bugs] #24499 [Core Tor/Torflow]: Bandwidth determination is flawed

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#24499: Bandwidth determination is flawed
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 Reporter:  Hassprediger      |          Owner:  tom
     Type:  defect            |         Status:  new
 Priority:  Medium            |      Milestone:
Component:  Core Tor/Torflow  |        Version:
 Severity:  Normal            |     Resolution:
 Keywords:  tor-bwauth        |  Actual Points:
Parent ID:                    |         Points:
 Reviewer:                    |        Sponsor:
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Comment (by starlight):

 Replying to [comment:3 teor]:
 > Replying to [comment:2 starlight]:
 > > Suggest you try removing the relay bandwidth limit.  Even in regions
 favored by the BWAuths, non-exit nodes rarely see more than 30% link
 utilization by Tor.  While the relay may still be rated lower than it
 should, it may acquire enough consensus weight to attract notable traffic.
 One megabit is not much.
 >
 > 30% is actually considered overloaded in most networks. 10% is good for
 low packet loss and low latency.

 My relay--with no `RelayBandwidthRate`--is currently loaded at 25%
 according to Blutmagie.  Nowhere near link saturation.  Ping-Plotter says
 packet loss is couple of packets every couple of hours and I never notice
 any QOS issues in my browsing as a result of the relay.

 > The last time I checked, the relay bandwidth limit was not active on the
 network. Please feel free to double-check, and if there is some limit,
 open another ticket to address that issue.

 I am not the reporter.  In the second sentence he states:  "I set
 RelayBandwidthRate to 1100, which is around 20% of my connection."  That
 would be the limit he explicitly set on just his relay.  I stand by my
 opinion that this is a very low limit, regardless of the continent one
 operates from.

 > > The path selection algorithm seems non-linear w/r/t low-end relays,
 where once one breaks above a certain level traffic goes up rapidly.
 >
 > This is probably due to the Guard and Fast flags. If you can find better
 settings, please open another ticket to tune those flags.

 At RelayBandwidthRate set to 1100 the reporter will never see the Guard
 flag.

 My observation is based on experience running on slower and faster speed
 connections regarding how much utilization comes at the relay--have years
 of experience running relays.  In particular, if you look at my namesake
 relay's history, you will notice much of that experience was with a
 painfully slow connection.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/24499#comment:4>
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