Connection over Internet with DynDNS

Hey folks,

I wanted to test the connection over Internet with the Gamestudio multiplayer. I have an open port (1337) and a DynDNS Host. I thought clients can join me with str_cpy(server_name,"omneybus.no-ip.biz");
but that doesn't work if I test it outside of my system.
session_connect is just for Pro, what can I do?

I found some infos: Last question is

Does my open port has to be between 2300_2400?

dplay_port = 1337;