[bittorrent] is there any linux command line bittorrent clientwhich support NAT traversal?

Andrew Brampton andrew at bramp.freeserve.co.uk
Fri Oct 21 04:44:31 EDT 2005


----- Original Message ----- 
From: "Brian Dessent" <brian at dessent.net>
To: <bittorrent at lists.ibiblio.org>
Sent: Friday, October 21, 2005 7:09 AM
Subject: Re: [bittorrent] is there any linux command line bittorrent 
clientwhich support NAT traversal?


>
> NAT traversal was never a part of the protocol design, other than the
> fact that NAT users can connect to non-NAT users but not other NAT users
> (unless ports are forwarded.)  BitTorrent uses TCP exclusively[*], and
> there's no way that I'm aware of to get around the requirement for at
> least one side to be able to receive incoming connections.  All the
> NAT-busting methods use UDP.  So don't get your hopes up.
>

Just to keep people on their toes, the inventor of NAT Paul Francis and his 
PhD Student S. Guha, have developed a way to do TCP NAT-NAT 85%-90% of the 
time depending on how the NAT boxes work, and if NAT vendors all stick to 
the exact same spec (which they hopes the IETF will forces them to do) then 
we will soon have 100% TCP NAT-NAT :)

Here is their paper (released not so long ago):
"Characterization and Measurement of TCP Traversal through NATs and 
Firewalls", S. Guha and P. Francis. IMC 2005.
http://nutss.net/pub/imc05-tcpnat.pdf

and their example source code (in java):
http://nutss.net/stunt.php faq: http://nutss.net/jstunt-faq.php library and 
example: http://nutss.net/jstunt-examples.php

Enjoy
Andrew 




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