Hey everyone, as far as I know, the DAs running the bwauth scripts conduct hourly bandwidth measurements. Depending on the advertised bandwidth of the relay node, a smaller/bigger file gets transmitted on a custom 2-hop-circuit and the transmission time determines the actual bandwidth. Now, here is my problem: Assuming that my relay node advertised 50MB/s, and is currently at 98% load (49 MB/s). To conduct the measurement, the bwauth script will send a 8MB file over my relay, but since it can only serve another 1MB/s, how will the bwauth script determine that my advertised 50MB/s is correct?
Hi, I think that in this case, every existing connection and transfers act as "best effort" (it means that used bandwidth for some connection aren't absolutely reserved), the new transfer is making a place by reducing just a little bit the others connection's available speed. If 50 active connection are using 1 MB/s each at the same time, with a total amount of 50 MB/s which is the maximum of a given server for example, then a new connection trying to get 1 MB/s will make the 50 Megabits divided by 51, then the usable bandwidth for all connection becomes 0,98 MB/s in the place of 1 MB/s When your relay is very overused and severe congestion occurs, then the bandwidth measurement will be very poor, this will reduce the weight of your relay in the consensus in order to reduce the congestion. The algorithm is designed to give the ideal consensus weight for your relay in order to be as close as possible of your maximum available bandwidth, without placing too much users on it (with too much users on it, the total used bandwidth will be at the maximum, but each user get a painful browsing experience because the available bandwidth per user becomes too weak) Bye ! Julien PS : if the advertised bandwidth is incorrect then congestion will occur and the consensus weight of your relay will be decreased because of poor performance during measurements, that's how possible cheating/disturbance is avoided in this case, I think. I think there is some documentation on this subject, by searching if you have some time and want to know more on this subject. Le 20/02/2017 à 18:39, Marcobr a écrit :
Hey everyone,
as far as I know, the DAs running the bwauth scripts conduct hourly bandwidth measurements. Depending on the advertised bandwidth of the relay node, a smaller/bigger file gets transmitted on a custom 2-hop-circuit and the transmission time determines the actual bandwidth.
Now, here is my problem: Assuming that my relay node advertised 50MB/s, and is currently at 98% load (49 MB/s). To conduct the measurement, the bwauth script will send a 8MB file over my relay, but since it can only serve another 1MB/s, how will the bwauth script determine that my advertised 50MB/s is correct?
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On 21 Feb 2017, at 04:39, Marcobr <marcobr@protonmail.com> wrote:
as far as I know, the DAs running the bwauth scripts conduct hourly bandwidth measurements.
Measurements occur on a random basis, I think every bandwidth authority tries to measure every relay at least once or twice every week. Every hour, recent measurements are averaged to produce a bandwidth weight for every relay. Then the directory authorities vote on these bandwidths, and produce a consensus containing the low-median. T -- Tim Wilson-Brown (teor) teor2345 at gmail dot com PGP C855 6CED 5D90 A0C5 29F6 4D43 450C BA7F 968F 094B ricochet:ekmygaiu4rzgsk6n xmpp: teor at torproject dot org ------------------------------------------------------------------------
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Julien ROBIN -
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teor