I am currently experiencing some SIP trunk issue .
Here is some background information:
I have a UC520 version 8.0 , Port WAN are directly connected to Internet with a public IP address (no Firewall, no NAT) .
Have config.the system to make call and receive call from a SIP provider .
I can make call from UC to external via SIP and receive call from SIP to UC IP phone.
When try to redirect the inbound SIP to CUE call fails .
Have already config. the transcode option to permit G729>G711.
Attach the Output of debug CCSIP all .
Any help would be greatly appreciated.