sipxcom sip system setup

i have successfully set up this sipxcom, it can work perfectly in intranet network using [login to view URL], but i cannot setup outside domain, i want to use sip outside network, i know there are instructions but i cannot fix the problem. I know i just miss very little thing. i will give you teamviewer to setp up my pc. You need to do: 1)help me to set up sip system using sipxcom, i need the sip can be use in internal and external network. 2) tell me what i have miss or did it wrong. 3) i will follow your instructions and set up the system again, to make sure i can set up external network in the future on my own.