nat server protocol tcp global X.X.X.X(public network address)15338 inside Y.Y.Y.Y(private network address) 15338（listening port）When PC at private network uses BIT to download files, it could initiate BIT connection via seed, and other BIT download operators could establish BIT connections with PC in private network via listening port mapped, so the more the number of BIT connections, the faster the download speed.
1. The principle of BIT download: the more the connections, the faster the download; additionally, you could upload files while downloading. BIT has two types of connections: one is that initiated by PC, and the other is connection with PC initiated by other download operators. BIT listening port functions as the port connecting with other download operators.
2. PC at public network could initiate connection with other BIT download operators via seed for download and upload of files, and other BIT download operators could establish connection with BIT listening