WebConf Lync 2010

Hello There,

I have setup a lync environment on my network, so far is working internally, I can do video conference, voice conference, from the outside I can only sing-in but I cannot join a conference from the outside, for example, if I create an invite from my Lync account and send it to my Gmail account I cannot join the meeting, I am getting like the website that is pointing on is not available, I am using all the defaults from Microsoft.

I have the edge server on a DMZ, and I have 3 Private IPs and 3 Public, so I am NAT-ing.
for SIP i am using sip.mycompany.com, for Web Conf I am using webconf.mycompany.com and for A/V av.mycompany.com, the DMZ addresses are

sip = 192.168.168.130
webconf - 192.168.168.131
av = 192.168.168.132

from the outside they are being mapped as

6x.xx.xx.150 for sip
6x.xx.xx.151 for webconf
6x.xx.xx.152 for AV

and on the topology builder where its says to specified the NAT address I am using the external address for AV

so, when I create a meeting using Lync the address to joing the meeting is:

https://meet.mycompany.com/lynsusername/<RandomLetters>

so on my external DNS what address or ip should resolve meet.mycompany.com ?? everytjing is working internally as I can go to meet.mycompany.com using my .COM internal DNS and I get the lync web app page and if a user is on my network and tries to join the meeting it will work, so now, how can I make this work for the external people?

I dont have a reverse proxy, I have a firewall and I am opening and port forwarding the ports.

Any ideas?