[tor-bugs] #1855 [Tor Relay]: Project: design for UDP transport

[Tor Bug Tracker & Wiki]

#1855: Project: design for UDP transport
-------------------------+--------------------------------------------------
 Reporter:  arma         |       Owner:                     
     Type:  enhancement  |      Status:  new                
 Priority:  normal       |   Milestone:  Deliverable-Mar2011
Component:  Tor Relay    |     Version:                     
 Keywords:               |      Parent:                     
-------------------------+--------------------------------------------------
Description changed by arma:

Old description:

> A popular topic over the years has been moving from TCP transport between
> Tor relays to UDP transport, and then maybe switching to some congestion
> control approach that better recognizes the real endpoints in the
> communication.
>
> We've been talking to Robert Watson and BattleZ of the FreeBSD project
> about helping to fund them to port the FreeBSD network stack to user-
> space. Lately the user-space networking stack has seemed like the primary
> stumbling block.
>
> We really ought to have a better intuition about what we're going to
> actually *do* once that stumbling block is resolved.
>
> We should write a draft design doc and spec for a future version of Tor
> based on UDP transport. One main goal is to identify areas of uncertainty
> that need to be solved before such a system can be built and deployed.
> Another aspect of that goal is to identify and flesh out unsolved
> research questions, and pros and cons to various tradeoffs that designs
> like this have made. For example, should we do TCP-over-UDP pairwise, or
> end-to-end? Various research groups have very strong feelings, and often
> their recommendations conflict.
>
> We might draw on five pieces of background work for ideas:
>
> 1) Joel Reardon's thesis:
> http://freehaven.net/anonbib/#reardon-thesis
>
> 2) The old ZKS designs:
> http://freehaven.net/anonbib/#freedom2-arch
>
> 3) Zach Brown's Cebolla:
> http://freehaven.net/anonbib/#cebolla
> http://www.cypherspace.org/cebolla/
>
> 4) Camilo Viecco's UDP-Tor design:
> http://www.petsymposium.org/2008/hotpets/udp-tor.pdf
>
> 5) Csaba Kiraly's work:
> http://disi.unitn.it/locigno/preprints/TR-DISI-08-041.pdf
>
> The design should be sure to include a transition plan, and a plan for
> how to let clients who need blocking-resistance (e.g. they need to look
> like SSL on the wire) continue to use the network.

New description:

 A popular topic over the years has been moving from TCP transport between
 Tor relays to UDP transport, and then maybe switching to some congestion
 control approach that better recognizes the real endpoints in the
 communication.

 We've been talking to Robert Watson and BattleZ of the FreeBSD project
 about helping to fund them to port the FreeBSD network stack to user-
 space. Lately the user-space networking stack has seemed like the primary
 stumbling block.

 We really ought to have a better intuition about what we're going to
 actually *do* once that stumbling block is resolved.

 We should write a draft design doc and spec for a future version of Tor
 based on UDP transport. One main goal is to identify areas of uncertainty
 that need to be solved before such a system can be built and deployed.
 Another aspect of that goal is to identify and flesh out unsolved research
 questions, and pros and cons to various tradeoffs that designs like this
 have made. For example, should we do TCP-over-UDP pairwise, or end-to-end?
 Various research groups have very strong feelings, and often their
 recommendations conflict.

 We might draw on six pieces of background work for ideas:

 1) Joel Reardon's thesis:
 http://freehaven.net/anonbib/#reardon-thesis

 2) The old ZKS designs:
 http://freehaven.net/anonbib/#freedom2-arch

 3) Zach Brown's Cebolla:
 http://freehaven.net/anonbib/#cebolla
 http://www.cypherspace.org/cebolla/

 4) Camilo Viecco's UDP-Tor design:
 http://www.petsymposium.org/2008/hotpets/udp-tor.pdf

 5) Csaba Kiraly's work:
 http://disi.unitn.it/locigno/preprints/TR-DISI-08-041.pdf

 6) Marc Liberatore's proposal 100:
 https://gitweb.torproject.org/tor.git/blob/master:/doc/spec/proposals/100
 -tor-spec-udp.txt

 The design should be sure to include a transition plan, and a plan for how
 to let clients who need blocking-resistance (e.g. they need to look like
 SSL on the wire) continue to use the network.

--

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/1855#comment:1>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online