When we have a device performing NAT between our TrixBox system and our providers, we can remedy this by making some changes to our configuration. We can manually change the configuration files from the web interface in order to make any changes for which we can find options. To reach this section, from the first page of the TrixBox web interface click the System Administration link as shown below:

Next, we should see the System Administration screen where we click on Config Edit.

Here, we can see all the notable configuration files involved with our TrixBox system that we can change manually.

We want to modify the sip_nat.conf file, so click on it to show us the file:

We want to add the following information as shown in the preceding screenshot:

[general]
externip=55.66.77.88 ; Change to match our external IP address
localnet=192.168.1.0/255.255.255.0; Change to match our network settings

The externip setting needs to be set to our public IP address. If we do not know...