[tor-relays] Tor bandwidth scanner "longclaw" slow to the US West Coast

[Felix]

Hi,

Am 16.08.2020 um 02:41 schrieb Neel Chauhan:
> Hi,
>
> I believe the Tor bandwidth scanner nicknamed "longclaw" is measuring
> relays in the US West Coast worse than other bandwidth scanners in North
> America. This happens on multiple ISPs, both ones I have and ones I don't.

The plots below can be a coincidence, but it shows at least there are
more parameters for unexpected observations:

The consensus of a relay in Germany shows:

moria1 Fast Guard  !HSDir Run Stab V2Dir Valid bw=17700
tor26  Fast Guard  HSDir  Run Stab V2Dir Valid
dizum  Fast Guard  HSDir  Run Stab V2Dir Valid
gabel. Fast Guard  HSDir  Run Stab V2Dir Valid bw=21800
danne. Fast Guard  HSDir  Run Stab V2Dir Valid
maatu. Fast Guard  HSDir  Run Stab V2Dir Valid bw=24000
farav. Fast Guard  HSDir  Run Stab V2Dir Valid bw=21500
longc. Fast !Guard HSDir  Run Stab V2Dir Valid bw=1800
bastet Fast Guard  HSDir  Run Stab V2Dir Valid bw=17300

The mtr plot for the same server shows the hop
"100ge1-1.core1.par2.he.net" is generating many packets losses.
Where "100ge14-1.core1.nyc4.he.net" puts milli seconds into the game:

                            Packets               Pings
  Host                    Loss%   Snt   Last   Avg  Best  Wrst StDev
  1. 91-143-90-251.gw.dsw-c6ka.as35366.net
                          0.0%    51    0.3   1.4   0.3  46.3   6.4
  2. po162.bbsw-h3-j1cr.as35366.net
                          0.0%    51    0.5   0.9   0.3   9.3   1.4
  3. po150.bbsw-h2-j1a.as35366.net
                          0.0%    51    0.4   4.5   0.3 189.5  26.4
  4. po205.bbsw-h4a-fra.as35366.net
                          0.0%    51    7.3   7.6   7.0  24.4   2.4
  5. 10gigabitethernet2-3.core1.fra1.he.net
                          0.0%    50    9.0  11.1   7.1  32.6   6.8
  6. 100ge16-2.core1.fra1.he.net
                          0.0%    50    7.7   7.6   7.3  13.9   0.9
  7. 100ge1-1.core1.par2.he.net
                         51.0%    50   17.0  20.2  16.7  39.2   6.6
  8. 100ge14-1.core1.nyc4.he.net
                          0.0%    50   87.1  90.1  87.1 102.7   4.3
  9. 100ge10-1.core1.ymq1.he.net
                          0.0%    50   99.4 101.3  99.2 109.7   3.2
10. estruxture-data-centers.10gigabitethernet1-1-40.switch3.ymq1.he.net
                          0.0%    50   99.3 101.0  99.1 136.5   6.2
11. 64.15.69.54          0.0%    50   98.2  98.1  97.8  99.0   0.2
12. anon.riseup.net      0.0%    50   98.4  98.4  98.0 100.3   0.5

Relays at other hosting locations choose for different routes and
longclaw sees them perfectly equal. It*s a case by case.

--
Cheers, Felix