I'm trying to understand how the bandwidth
authorities work, and reading the spec [0] got me only partway to an
understanding, so I'm trying to use Stem to see what the bwauth
measurements look like in practice. I'm working off the "Votes by
Bandwidth Authorities" example on the Stem webpage [1].Â
The query there returns a RouterStatusEntryV3, so I've been looking at
the "bandwidth" and "measured" fields to try to understand what's going
on [2]. "Bandwidth" maxes out at 10,000 (kb/s??) but "measured" doesn't
seem
to have the same ceiling, which made me realize that they aren't in the
same units. Damian mentioned on IRC that "measured" might be returning
the
bwauth weight rather than a bandwidth, but what is the meaning of that
weight? Does a higher "measured" value mean a higher bandwidth, or a
higher bandwidth relative to what the relay advertises? In other words,
if I
sorted the descriptors by "measured" value, what would that order mean?
Separately,
is there a way (using Stem or some other tool) to see the raw bwauth
measurements rather than the weights? Is that a calculation I can
reverse? I haven't looked into the historical data on CollecTor yet,
but ideally, I would like to use the historical data to figure out how
effective the bwauth measurements seem to be in different situations
(for example, the misconfigured to very high bandwidth relay this past
February seems to have produced confusing bwauth measurements [3]). If
I'm looking for interesting events in the historical bwauth data, would I
be looking for high "measured" values, rapid changes, or ...?
Thanks!
Anna
PhD Student, University of Washington