{
  "is": "experiment",
  "title": "Tor network with congestion control",
  "createdAt": "2022-05-03 16:00:00 +0000 UTC",
  "permalink": "https://torprojectstatus.org/experiments/2022-05-03-congestion-control/",
  "affected": ["Network Experiments"],
  "filename": "2022-05-03-congestion-control.md",
  "body": "\u003ch2 id=\"what-changed\"\u003eWhat changed?\u003c/h2\u003e\n\u003cp\u003eWe started deploying congestion control on the live Tor network.\u003c/p\u003e\n\u003cp\u003eUsers 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 \u003ca href=\"https://metrics.torproject.org/bandwidth-flags.html\"\u003eour network metrics\u003c/a\u003e.\u003c/p\u003e\n\u003cp\u003eAs 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.\u003c/p\u003e\n\u003cp\u003eOur \u003ca href=\"https://metrics.torproject.org/torperf.html\"\u003eperformance metrics\u003c/a\u003e will remain unchanged until we upgrade those onionperf instances to 0.4.7, which will likely also happen towards the end of May.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eUpdate, 2022-05-17 14:00UTC\u003c/strong\u003e: bastet has been running Tor 0.4.7.7 on its bandwidth authority since 2022-05-06 while we are still in the process of upgrading the network. While that won\u0026rsquo;t influence the stablitiy of the network itself, it might create noise in bastet\u0026rsquo;s votes.\u003c/p\u003e\n\u003ch2 id=\"when-did-it-start\"\u003eWhen did it start?\u003c/h2\u003e\n\u003cp\u003eAt 2022-04-25 19:00:00 UTC.\u003c/p\u003e\n\u003ch2 id=\"when-did-it-stop\"\u003eWhen did it stop?\u003c/h2\u003e\n\u003cp\u003eThere is no clear date when we transitioned away from the experiment phase.  At the time of writing this (06/09/2022 13:30 UTC) roughly 82% of exit relays (by consensus weight) have upgraded to Tor 0.4.7. Additionally, we have upgraded our onionperf instances and Tor Browser starting with 11.0.13 (released on 05/23/2022) is shipping with Tor 0.4.7 as well.\u003c/p\u003e\n\u003ch2 id=\"what-potential-problems-to-look-for-and-how-to-report-them\"\u003eWhat potential problems to look for, and how to report them?\u003c/h2\u003e\n\u003cp\u003eRelays might see \u003ca href=\"https://support.torproject.org/relay-operators/relay-bridge-overloaded/\"\u003eCPU overload\u003c/a\u003e in which case operators could consider to \u003ca href=\"https://support.torproject.org/relay-operators/bandwidth-shaping/\"\u003erate-limit bandwidth\u003c/a\u003e. Additionally, if operators pay for bandwidth by the gigabyte, they could \u003ca href=\"https://support.torproject.org/relay-operators/limit-total-bandwidth/\"\u003econsider hibernation\u003c/a\u003e if costs go up.\u003c/p\u003e\n\u003cp\u003eIf you think something has gone wrong with enabling congestion control feel free to start a discussion on the \u003ca href=\"https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays\"\u003etor-relays\u003c/a\u003e mailing list or a topic in our \u003ca href=\"https://forum.torproject.net/c/support/relay-operator/17\"\u003eforum\u003c/a\u003e.\u003c/p\u003e\n"
}