From inside of the office I can make voice calls from one user to another just fine. From outside of the firewall it does not work. I can chat but when I try voice it says Connecting Call.... then Call Ended. I can connect a vpn client from that same remote computer and it will work fine. My OCS server has a public ip nat with ports 80-65535 open just for good measure but it still doesn't work. There are no errors in the event log. What could my problem be?