External and NAT'd IP Addresses - using both on Asterisk?

Hi all,

First Asterisk installation nearly complete; just one final issue.

We’ve deployed our Asterisk box on a NAT’d address behind our firewall (say We have two SIP trunks sending inbound and outbound calls to and from handsets behind the firewall. Voice mail, MeetMe all works great.

What I’d like to be able to do now is configure a softphone to be able to log in to the PBX when I’m traveling, i.e. from anywhere. So our sysadmin configured our router to masquerade as one of our public (i.e. real IP) addresses, and forwarded ALL traffic (TCP and UDP) sent to that address to our internal IP’d Asterisk.

Now Softphones inside our firewall can happily connect to the external IP, and from the outside I can SSH, HTTP etc to the Asterisk server using the public address; however the softphones won’t connect (Asterisk cant even see them try from the console).

Our sysadmin swears that externally generated traffic to any port is hitting the Asterisk server. What I wanted to ask is if there is anything else I need to do to configure the Asterisk server to think it should respond to the external IP address?

Any advice appreciated!


Try to put in soft phone STUN server.