Inbound Route No Audio

I have the following scenario, Free Pbx & 2 Sip Extensions(100 y101) behind a NAT Router , the router connected to public static IP, ports 10000-20000 TCP/UDP and 5004-5062 TCP/UDP mapped to Free PBX Server (, No firewall in Pbx Server
Outgoing Calls works perfect, the problem is when the pbx receive a DID from outside provider , I have a Catch All route terminating the call the extension 100
The call ring at the extension 100, was answered but no audio is heard at the extension side,
I will apreciatted any help

Augusto M