Say I have Peer A and Peer B. Peer B is a part of a P2P network with a DHT used for locating files. There are many other peers in the network.
Peer A and Peer B are behind NAT. Not the same NAT, two different ones. Assume Peer B starts magically in the DHT and is happily communicating with other peers.
Let's say that Peer B gives Peer A his public IP address and port that he found via some other peer (in the network) letting him know the address he was at publicly.
How does Peer A connect to the DHT and is it possible without using a server of some sort to facilitate the punch-through?