We started deploying congestion control on the live Tor network.
Users of Tor versions 0.4.7.5-alpha and above will experience faster performance when using Exits or Onion Services that have upgraded to 0.4.7.5-alpha and above. This faster performance will also increase the Advertised Bandwidth of relays, similar to our previous flooding experiments. Thus, the overall capacity of the network will appear to increase on our network metrics.
As more clients upgrade, particularly after a Tor Browser Stable release with 0.4.7 is made, the consumed bandwidth of the network should also rise. We expect to make this Tor Browser Stable release on May 31st, 2022.
Our performance metrics will remain unchanged until we upgrade those onionperf instances to 0.4.7, which will likely also happen towards the end of May.
At 2022-04-25 19:00:00 UTC.
It is still ongoing. We will declare this experiment “concluded” once most of our Exit relays have upgraded to Tor 0.4.7 or later, have upgraded the onionperf instances, and released Tor Browser Stable with Tor 0.4.7.
Relays might see CPU overload in which case operators could consider to rate-limit bandwidth. Additionally, if operators pay for bandwidth by the gigabyte, they could consider hibernation if costs go up.