I am currently having two separate problems.
1) When i make calls from external to the grandstream there is no audio
2) All external SIp calls are terminated after 32 seconds
I am currently using NAT and NOT using the standard asterisk port of 5060 or standard RTP ports (currently using 10,000-11,000)
I need some help configuring the firewall to enable the SIP properly on the firewall.