i'm doing some research about the packets (c->s)that telling the server which game port the host is using.
i did logged 0x1C but i found no changes when i changed the game port.

Just look here: http://bnetdocs.valhallalegends.com/sequence.php

At the end of the WC3 Logon sequence the client sends a NETGAMEPORT Packet (0x45). I just checked it an when I change the port in warcraft, it also sends the new port.