can not hear voice in two direction

[dwaik]

i configure 3cx and everything is okey ,i also configure goip gateway and it is fine.
i create sip trunck for local provider ,and the sip goes up and connected,when making call , the call is fine but no one hear anything in the two way .
what is the problem ?
my system admin confirm that no ports closed and the sip provider tell the same.
what is the problem ?

 

[leejor]

What is your set up? Is 3CX hosted on the local LAN? If not, do the sets use an SBC, STUN, or VPN? Does the 3CX Firewall test pass?