How can I make communication between two host like torrent?

Question

Hi,

I want to communication between two host in different networks which are behind NAT and I want to use the torrent idea which is not a server and it is like a tracker that just get the basic information of two hosts then send these data to both of the hosts next the hosts have the data of each other and make a program to communicate and chat between two host which are behind NAT.

PLEASE GUIDE ME.

THANK YOU VERY MUCH.