Opened 5 years ago

Closed 22 months ago

#13589 closed enhancement (wontfix)

bridge authority could do bandwidth test along with reachability test

Reported by: arma Owned by: isis
Priority: High Milestone: Tor: unspecified
Component: Core Tor/Tor Version:
Severity: Normal Keywords: tor-bridge, tor-bridgeauth, measuring bandwidth
Cc: aagbsn, mikeperry, isis, yawning Actual Points:
Parent ID: Points:
Reviewer: Sponsor:


It's increasingly clear we want to know which bridges are slow, so we can treat them differently (e.g. never give out the slow ones).

I heard Mike and Aaron talking about implementing a remote bwauth style thing to remotely measure how much throughput they could get from each bridge.

But I think we don't need an accurate bandwidth estimation -- we need to know if they're too slow or not too slow.

So it occurred to me that Tonga's reachability test is nearly doing the test we need. If it pushed some traffic down its reachability circuit, maybe in a way that triggered some traffic in response or maybe just by making a loop and sending the traffic back to itself, then it could see what it gets, and put that number as the bandwidth weight in the bridge networkstatus document, and bridgedb could just use it.

I'm normally not a fan of complexifying Tor when some outside service could be written to do the same thing. But we're so close! :)

Another argument in favor is that to limit blocking risks, we want to limit the number of points on the network that probe the whole set of bridges.

Child Tickets

Change History (8)

comment:1 Changed 5 years ago by arma

Cc: aagbsn mikeperry isis yawning added

comment:2 Changed 5 years ago by arma

Yawning points out that in the glorious future of pluggable transports and closed bridge ORPorts, all this reachability stuff is going to get messier. Last I checked we have no plan for that.

comment:3 Changed 4 years ago by isis

Keywords: 028-triage added
Owner: set to isis
Priority: normalmajor
Status: newassigned

Related to #5211; this should be taken into account in the discussions pertaining to that ticket. Whatever proposal we come up with should definitely address this.

comment:4 Changed 3 years ago by isis

Keywords: TorCoreTeam201608 added

Adding to my august tickets.

comment:5 Changed 2 years ago by nickm

Keywords: 028-triage removed

comment:6 Changed 2 years ago by nickm

Keywords: TorCoreTeam201608 removed

comment:7 Changed 2 years ago by nickm

Keywords: tor-bridgeauth measuring bandwidth added
Severity: Normal

comment:8 Changed 22 months ago by isis

Resolution: wontfix
Status: assignedclosed

This is currently being implemented as an external (Rust) program by an intern, which seems safer than doing more HTTP fetches and servers in C. Closing for now, but feel free to reopen if we really want the tor process on the BridgeAuth to do the bandwidth testing.

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