So you are having one way or two way audio issues? And do you have the PBX setup to do NAT? Because this is completely a networking configuration issue. With all the private LANs I'm seeing and the fact that all the debugs show "No NAT" this isn't going to work until you resolve your networking issues.
You do realize that the "Override External IP" is for an IP or FQDN that's on the WAN side of your router, not the LAN so having a private LAN IP will not work. You also cannot have two override IPs on the Chan_SIP trunk.