[Bloat] BitTorrent and IPv6 [was: tackling torrent...]

[Juliusz Chroboczek]

> It also appeared to show that transmission chose one and only one 
> of the ipv6 addresses available on this box.

Yes.  My code explicitly binds the UDPv6 socket to a single address.  
Anything else, and the IPv6 DHT gets confused since Kademlia requires 
having a single address for all peers.

We could in principle use the kernel's address selection for outgoing µTP 
connections.  We could even announce multiple addresses over Kademlia, but 
that would require a fair amount of work.

> This is me capturing the last 30 seconds of an ubuntu download:

> http://snapon.lab.bufferbloat.net/~d/withtorrents/last30secondsoftorrentvs1upload.png

Nice.  (Interesting how the "endgame" algorithm causes the download 
throughput to explode.)

> 6969 was the most common inbound port.

It's the default, but aficionados tend to choose a random high port, in 
case 6969 is blocked or throttled.

>> 4. Most importantly, I've implemented IPv6 support for the DHT (BEP-32) [1].  
>> BEP-32 is now implemented by Transmission, Vuze, Tixati, KTorrent and 
>> Shareaza.
> 
> In light of source specific routing, perhaps that BEP needs an addendum.

I'm no longer actively working on BitTorrent, just maintaining libdht in 
my copious free time.  Place aux jeunes.

-- Juliusz