[tor-relays] Port-Based Best-Fit Circuit Selection

[Paritesh Boyeyoko]

Hello --

First of all, let me apologise if this has been covered before on this list.

A couple years ago I took more than a passing interest in Tor and decided to run a non-exit 
relay on a VPS, which lasted until an upstream provider complained.  I've recently set up another 
one, and while it settles into the network, it got me thinking about utilization.  Much has been 
made of the fact that Tor is circuit-based rather than packet-based, and also of the fact that 
faster relays attract more traffic.

So, I was thinking that in the same way that Tor relays have port-based exit policies, could they not 
also have port-based entrance policies?  In other words, cause deliberate selection of a "slow" path 
based on the protocol intended to be used.  So for example, HTTP would favour faster circuits, while 
the likes of email (POP, IMAP, SMTP), XMPP and IRC would favour slower circuits (being mostly text-based).

Perhaps the entrance policies could be maintained on-network (perhaps with "authority servers", with 
clients downloading the policies when they start up, rather than having them hard coded or configured 
client-side?

Just some ideas. :)

Best,
-- 
Paritesh Boyeyoko
parity.boy at gmail.com