Draytek Router with 3CX Setup
Please ensure vi a the Open Port under NAT from the Draytek Portal that the following ports are open and forwarded to the correct local IP Address of your 3CX Server.
TCP / UDP 5060
TCP / UDP 5090
Disable SIP ALG
Sys sip_alg 0
Draytek Routers with Built-In VoIP
If your Draytek Router comes with the built-in VoIP Service using the Draytek Vigor 2830Vn please ensure you disable this. Ensure the firmware is on at least 3.6.3.
Login to the Router via SSH and run the following command voip sip misc –D 1
The router will then reboot and VoIP Services will be disabled.