Please follow the below step by step instructions to properly configure your SIP Trunk.
The AVOXI cloud is set to accept calls from the IP address directly associated with your IP address ONLY. AVOXI authenticates using the IP address from where we receive the calls. There is no need to authenticate against username and password.
Make sure to route calls to any of AVOXI’s IP addresses using the specified ports above.
As mentioned before, AVOXI authenticates against the IP address from where the calls are sent. If your public IP address changes, please make sure to click on the associated SIP trunk name and make the appropriate change to the IP address.