[tahoe-dev] Advertised invalid node port

[Brian Warner]

On 6/16/10 2:12 PM, slush wrote:
> Hi Brian,
> 
> Did you consider something like NAT punch [1]?
> 
> And did you consider uPnP?

Briefly. Those are some of our oldest enhancement-request tickets:

 STUNT: http://tahoe-lafs.org/trac/tahoe-lafs/ticket/50
 UPnP:  http://tahoe-lafs.org/trac/tahoe-lafs/ticket/169

Nobody's put much energy into them, though: they weren't on the top of
the use-case list (and still aren't, unfortunately).

The last paper I read (on one of the P2P lists, probably 5 years ago)
suggested that STUNT depended drastically on the particular router
firmware both parties were behind, so it recommended something like 5
different algorithms to be tried in series, and still only worked about
half the time. I also remember reading that something like 70% of home
routers that advertise UPnP functionality don't actually work.

But yeah, I agree that an Introducer (or some other globally-known
globally-visible server) could provide the important coordination
service for the STUN/holepunching techniques.

We've vaguely thought that moving to an HTTP-like protocol might make
this easier. Also, moving to a more UDP-based protocol would make it
easier (enabling STUN, which lots of bittorrent work has gone into,
rather than STUNT).

cheers,
 -Brian