Is anyone familiar with "Ventrilo" its a voice server software, i cant seem to host a server through my router

[Camofrog]

I have a Westell Modem/Router and a Microsoft standard 5 port hub. my couple of computers are hooked to the hub, which is hooked to my router. i have gone in and port forwarded the ports used by ventrilo, but.... for some reason i cant port forward to an IP on my router, so maybe its in my router? anyway i cant get it to alow people to connect from the internet, it does work across the LAN tho. can any one help with this? I do know others who have gotten it to work but they have different modem/routers?