[tor-project] The tor network is constrained by.... (meek, exits, etc)

[Karsten Loesing]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

Hi Tom,

On 10/01/17 20:13, Tom Ritter wrote:
> I am continually getting asked this question and then asked to back
> it up. I'm hoping the metrics team might be able to guide me
> here....

I'll give this a try, but I wouldn't say that the metrics team is your
best bet here.  We're busy providing all the data, but we're spending
way less time on looking at it than you would expect.

> Firstly, while we don't have (public) datasets showing this, I am 
> fairly certain that the public meek bridges have their bandwidth 
> capped (to limit costs) and raising that cap would directly
> improve the speed of meek users. (Implying that the bottleneck the
> majority of the time is the meek transport.)  Right?

That's also my intuition, but I don't have the data you're looking
for.  David would know better.

> Secondly, I know it's too simplistic to say "Our exits are
> operating at 85% of capacity, our guards are 65% and our middles at
> 40%" (for a host of reasons, including guard/middle overlap) but
> how close can we get to something simple that demonstrates more
> exits will help the (non-bridge) network the most? (If that is in
> fact the case!)

I don't know an easy answer to this, but you could look at consensus
bandwidth weights for a start:

https://gitweb.torproject.org/torspec.git/tree/dir-spec.txt#n2699

The latest consensus bandwidth weights are:

bandwidth-weights Wbd=0 Wbe=0 Wbg=4127 Wbm=10000 Wdb=10000 Web=10000
Wed=10000 Wee=10000 Weg=10000 Wem=10000 Wgb=10000 Wgd=0 Wgg=5873
Wgm=5873 Wmb=10000 Wmd=0 Wme=0 Wmg=4127 Wmm=10000

If you go add many more guards or exits, you should observe how those
weights change.

You could also ask Mike for more details.

> I might have more questions to relay, but for now these seem to be
> the main ones.

Sounds good.  You should also ask relay operators on the tor-relays@
mailing list.  Though asking on this list is a good start, too.

All the best,
Karsten

-----BEGIN PGP SIGNATURE-----
Comment: GPGTools - http://gpgtools.org

iQEcBAEBCAAGBQJYfkIgAAoJEC3ESO/4X7XBnYoH/Rt4SO9vjY56oTPO77X3cUeI
r59L0aCU/8gaHxvdGecraJGrIYsIW/Nq8y+88NosZeONH8dSFU9FL2ifnKF88rFB
0CCp7+JHGb9M3nmSvyFXMgDsOlYEc/4EHyE7ykqp2F/FuxRV/0TkNz32kJNZNtV8
/sXIZ0BN7I3L6pT0YGAOh21MZ2mxb0rKd3Sm4QT45ZwPZQFXQXbPg9Xfls7dKc5g
dObhrLv9UO0od3/+FXEDf1MIG3pnTwJFEdGer02iGJAFYPkIghYGOCM9nIzI2BrJ
XA/fhAa2MgiEGJz8D3jLbbq9NKrrap5wAtsHWHhafRAtBUYBGdsYtjU3G7O+dRc=
=Fjqx
-----END PGP SIGNATURE-----