On Tue, Sep 16, 2014 at 05:43:45AM +0200, Karsten Loesing wrote:
On 16/09/14 03:36, David Fifield wrote:
In comparing the user graphs of pluggable transports, I found that there seems to be a correlation between the graphs of flashproxy and meek. [...]
To figure this out I'm thinking of i) counting bytes transferred on the flashproxy and meek external ports, or ii) moving one to a different bridge (or different tor instance), to see if the effect remains. Do you have any other ideas?
Hi David,
here's what I think might cause this: we're counting consensuses downloaded from a bridge via any supported transport, and then we're attributing those downloads to specific transports based on what fraction of IPs connected per transport.
I see! Thank you. I imagine it would make a big difference in this case, because flash proxy and meek are polar opposites: flash proxy gets connections from tons of random IPs (often different IPs for the same client), and meek is always getting connections from the same CDN edge servers (the same IP for many different clients). If I understand it right, we are over-counting flash proxy and over-counting meek.
What we should do instead is count consensus downloads by transport. There's a ticket for this, but nobody is currently working on it:
https://trac.torproject.org/projects/tor/ticket/8786
Your idea ii) should fix this.
Of course, you'd be in a good position to test a patch for #8786. Would you want to hack on that?
We'll see :) For the time being I'll try isolating the transports and see what effect it has.
David Fifield