Vpanel shows my external IP address.
In your sip.conf did you set your externip= or externhost= information? Also, my sip.conf has nat=yes in it. You also need to set the localnet=. If you are using PBX In a flash, trixbox, etc you might need to edit a custom config file since the standard ones get overwritten. I am running AstLinux so it is a basic Asterisk install.
Code:
externhost=fully qualified domain name of my outside IP
localnet=192.168.1.0/255.255.255.0
externrefresh=300
nat=yes
externhost can also be externip=xx.xx.xx.xx if you have a static IP.