[e2e] using p2p overlays to overcome recursive NATs/realms

[Melinda Shore]

At 10:19 AM 2/8/02 +0000, Jon Crowcroft wrote:
>the real situation is that packets might traverse multiple natted realms (c.f. realm
>specific ip) - in this scenario, discovering the mapping involves discovering a path of
>several mappings-
>
>soluton might be to start a p2p service, which propgates mappings - take the ideas from
>stun, turn, rsip etc, and use them repeatedly...where multicast is available use it

I've proposed using an RSVP-like mechanism, which not only solves
the problem of finding the outermost address with respect to the
other guy, in the case of nested firewalls and NATs it also permits
the selection of the "correct" address for the firewall pinhole.
It generally gets around a number of sticky problems related to
discovery and topology.  See 
http://www.ietf.org/internet-drafts/draft-shore-friendly-midcom-00.txt

Melinda