Site to Site VoIP Issues

Hi All,

I'm having issues with IPSec Site to Site and VoIP. 

Here is my setup.

I have a pbx server running on a network with a FortiWifi30D. The FW30D has a Site2Site connection with a FortiGate60E. I have an IP Phone in the FG60E network. The IP Phone is able to register with the pbx on the FW30D. I can call from my cellphone to the IP Phone on the FG60E, it will ring and can pickup. However, I cannot hear anything from the IP Phone on my cellphone but the IP Phone can hear everything I am saying.

SIP ALG is not enabled as I have the VoIP security profile disabled in the Features section. I assume that is how it works. I have tried disabling SIP Session helper, but after disabling it, i can no longer register any of my phones. 

The VoIP system works perfectly from the FW30D network and is able to take calls. It's only the IP Phone on the FG60E network that is giving me issues.

Both the FW and FG are running 5.4.5.

Help is greatly appreciated.

Thanks!