[tor-relays] New Test for Measuring the Accuracy of Tor Relays' Advertised Bandwidths

[Johnson, Aaron M CIV USN NRL (5543) Washington DC (USA)]

    >      Okay, I read that, but I do not see where you offer any method to
    > account for other traffic that the relay being tested may be dealing with
    > at the time you are testing it.  IOW, your testing procedure would be fine
    > if only the tor network, or at least each relay while it were being tested,
    > were entirely idle w.r.t. the traffic of other users.  This is the same
    > defect that the authorities' testing procedures suffer from.
    >      Do you have a solution to offer?

    I guess it depends on what your goal is as to whether calling it a
    defect or not. For the test at hand, sure, we can't test as if no user
    activity would be ongoing but that's not too important if we want to
    test whether the advertised bandwidth significantly underestimates the
    true capacity of Tor relays.

I do not believe there is a defect, or at least I don't understand the stated concern. If by "other users", you mean the Tor users other than the speedtest client, then there is no problem because the relay's advertised bandwidth takes into account all Tor traffic, regardless of user. If, however, by "other users" you mean users of other applications running on the same machine as the relay, then (1) if such other traffic is relatively constant, then the measurement is correct as we want to measure the maximum available capacity *for Tor users*; but (2) if such non-Tor traffic comes in infrequent bursts, then it is true that such a burst may occur during a speedtest measurement and inaccurately indicate low capacity, but given that such bursts are infrequent, this problem should occur infrequently among all Tor relays.

Best,
Aaron