Weird situation, we have an external location which if they originate the call we cannot hear them, but if we originate the call to them everything works fine. 

The configuration we have is Sense as firewall that sends and has all stipulated Freeswitch ports open and forwards incoming ports to the Freeswitch server (Ubuntu/Freeswitch/fusionpbx)

Internal  to internal call works

Internal call to the external location works  Both parties can talk without issues.

External location to Internal location:  we do not hear them, but they can hear us.

External location call to external location :  the originating caller cannot be heard, the second leg works perfectly. (This suggest that it is not a firewall issue but a configuration issue.)

External location calls to the voicemail and can record without problems a recording.

The problem seems to be limited to the first leg of the call, in that if it originates from an external location the first leg cannot be heard.

Any suggestions on how to fix would be appreciated.  Thanks!

Cjb