Need help about gxp phone use by openvpn on pfsense

[thanhtrung411]

Dear all,
I installed and configured pfsense already. When finish the outside phone can connect to openvpn server and make a call to inside phone, everything is ok but the inside phone cannot call to the outside phone. Is there anyone get this issue b4 ? I need your any help or advice about this.
Thanks for your reply in advance.