[tor-bugs] #9574 [Tor]: Process ntor create cells before tap create cells?

[Tor Bug Tracker & Wiki]

#9574: Process ntor create cells before tap create cells?
---------------------------------------+------------------------------------
 Reporter:  arma                       |          Owner:                    
     Type:  enhancement                |         Status:  new               
 Priority:  normal                     |      Milestone:  Tor: 0.2.5.x-final
Component:  Tor                        |        Version:                    
 Keywords:  tor-relay, maybe-proposal  |         Parent:                    
   Points:                             |   Actualpoints:                    
---------------------------------------+------------------------------------
 Motivated by http://nsl.cs.columbia.edu/papers/2013/cellflood.raid13.pdf

 A) In the attack case: If we're under attack by somebody flooding us with
 tap create cells, it would be nice if the ntor creates get processed
 before this flood. If this strategy forces them to flood us with ntor
 create cells instead, that raises the expense.

 B) In the normal case: Since handling ntor create cells is faster than
 handling tap create cells anyway, we could get them out of the way earlier
 and improve performance even more for folks using ntor-based circuit
 handshakes.

 We already prioritize create-fast cells in exactly this way, though
 implementation-wise it'll probably be different. For the implementation
 here, maybe we'll be happiest just keeping two onionskin queues, one for
 each type.

 The only downside I can see is that it'll be harder to measure how much of
 a performance improvement we get from ntor creates, since now we speed it
 up in two ways that are hard to separate.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/9574>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online