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

[Jon Crowcroft]

so the problem with most the proposed solutions to workign around nats
is that they really assume there are only 2 realms - 
the great unwashed internet, and the poor deprived natted user. 

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

where one can infer the infernal internal algorithm used by a nat, use it. 

if the p2p service thus built (we might call it an InterNAT) has either dynamic DNS update, or
uses ipv6 itself, then to provide global reachability is quite simple...

 cheers

   jon