DTMF issue with NAT issue

I am new to this forum and also new to the FREEPBX. I am trying last few days to figure out my issue. My scenario:

I am trying to learn before I rent a hosted server for FREEPBX.

Outside World (ISP) -->Netgear 150N Wifi Router(has a static real IP (example)) -->Windows 2008 R2 Server Box ( --> HyperV VM where I installed FREEPBX (

My Inbound route with DID: DID Number —>

My NAT settings (Settings–>Asterisk SIP Settings)

NAT Settings: no
IP Configuration: Static IP

External IP:
Local Network:

In my Netgear, I turn setup 2 port forwarding for 5060 port and 10000-20000 port both is pointing to (My FREEPBX Box)

So now my issue is:

  1. If I keep Local Network: Blank, DTMF signal detected but X-Lite or Yate Client (Softphone) does not work.
  2. If I keep Local Network to>DTMF signal NOT detected but X-Lite or Yate Client (Softphone) work.

For option 2: everything works like I call from my cell phone to DID number and my softphone ringing, I pickup the phone and I can hear everything except for IVR DTMF signal not detected.

“NAT Settings: Yes” does not help.