Your Linux Distribution: (Redhat CentOS release 4.4 (Final))
Your FreePBX version: (2.2.1)
Your Kernel version: (Linux asterisk1.local 2.6.9-34.0.2.EL #1 Fri Jul 7 19:24:57 CDT 2006 i686 i686 i386 GNU/Linux)
I am running Trixbox and have several PAP2 adapters working fine internally, but I have one I'm trying to get to work externally. Both environments are nat'ed. I can get the pap2 adapter to register remotely and it can call internal extensions but it can't receive any calls nor can it make any external calls.