trouble with calls audio

I, too, am having this same problem. Any insight anyone can provide would be greatly appreciated!

I am using trixbox 2.8.0 and am having similar issues.

Started with a completely default install of trixbox 2.8.0. *not in a VM, running on hardware.
yum clean all
yum -y update
reboot
Added extension
Added IVR
Added 3 SIP trunks.
Added outbound rules.
Added inbound rule.
Rebooted and tested.

I have 3 trunks set up and can make and receive calls to these providers with no problems form a soft phone inside the LAN.\

When the soft phone is outside the LAN, it registers and I can dial the DID from my cell phone and I hear the IVR and make my choices. The soft phone will ring if I choose that option, but there is no voice once the connection is established. The same problem occurs when dialing out from the soft phone to my cell phone or any other number.

My internet service is AT&T's UVerse and the router is their standard 2wire UVerse router.

I have forwarded UPD ports 5060 - 5070 and UPD ports 10000 - 20000 through to the trixbox.

I have tried the soft phone from 3 different external networks with the same results every time.

For me, my sip_nat.conf shows (no header tags, it was blank when i first went here)

nat=yes
externhost=ssss.ddddddd.com
localnet=10.0.0.12/255.255.255.0
externrefresh=20

I have perfect functionality inside the local network. and my trunks with my inbound and outbound SIP providers work great. My only problem is getting a SIP device aka X-Lite to work outside the local network.

I feel I must be missing something really simple. X-Lite registers, makes calls and receives calls. There is simply no audio on said calls. Tried on 3 networks as noted above, and also on multiple computers on one of those networks. Same problem with every trial.

my localnet is 10.0.0.0/255.255.255.0 that was a typo when I made the post last night.

Now you know the internal IP at my house.

I am still having problems with this. Everything works fine inside the LAN of course. Everything seems to be working on the port forwarding because the soft phone registers, the web interface works and the SSH connects. All from the public IP/dns name from all 3 networks I have access to test on. I can make and receive phone calls. I hear the IVR on incoming calls. Just no audio on a connected call.

any suggestions on what I may have done wrong?

I've configured the port forwards in the router.

udp public:range 5060 - 5070 -> trixbox:range 5060 - 5070
udp public:range 10001 - 11000 -> trixbox:range 10001 - 11000
tcp public:81 -> trixbox:80
tcp public:22 -> trixbox:22

I've set the sip_nat.conf with

nat=yes
externhost=pbx.name.tld
localnet=10.0.0.0/255.255.255.0
externrefresh=20

I've set rtp.conf with

[general]
; RTP start and RTP end configure start and end addresses
rtpstart=10001
rtpend=11000

Problem solved. So this insinuates my trixbox is not resolving DNS correctly?

My IP address has not changed in over a year, but I am not paying for static, so it can change.
I have a dyndns setup and then my actual domain is aliased to the dyndns domain name (GoDaddy's full DNS controls are nice).

nslookup pbx.mydomain.tld from the CLI resolves correctly to the extrernal IP.
ping to www.google.com works.

The Public IP on the System Status page of the GUI shows a big bold Service Unavailable.

** Update **

I fixed this issue by simply replacing the default WRT54GS firmware on my Linksys router with the open-source DD-WRT. Works flawlessly, now! :)