Trying to use FreeBSD as a home router, how to setup VOIP to pass through?

[Lucas Holt]

My home network is currently setup with a lowend router from my phone  
company.  Its not very good and i have my only phone service through  
it using VOIP.  I've managed to get the rest of my network (3  
computers) behind the freebsd machine (computer 4).  The problem is  
that i'd like to move the voip router behind the freebsd machine.   
I'm assuming i need to do some sort of port forwarding to pull this  
off.  I've done some googling but can't seem to find good  
documentation on what ports to forward or how one would do port  
fowarding to another host.

I'm using FreeBSD 5.4 stable (week or two old), ipfw and natd with a  
divert rule in place and practically no other configuration.  Does  
anyone have any resources on forwarding voip traffic?

My long term goal is to get voip working and then setup an ip 6  
tunnel with HE.

I am not currently subscribed to questions so please CC me in replies.

Here's a rough idea what my network is like

cable modem
    +
    +
   voip router
   +
   +
   freebsd machine
   +      +         +
   pc    mac    mac

Everything is setup wtih IP4 at the moment.

Lucas Holt
Luke at FoolishGames.com
________________________________________________________
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Think PC.. in 2006 you can own an Apple PCintosh. Whats next, windows  
works?