The “Carriers” section allows you to add built-in and custom SIP trunks and assign them to users.
Click “+New Carrier” to create a new SIP trunk. If you are looking to add a custom SIP trunk to “Bring your own carrier” (BYOC), check the “Use your own carrier” checkbox, and extended SIP settings will appear.
After filling in the fields with the information provided by your SIP carrier, go to the “Routes” tab to configure the permitted destinations and prefixes.
For example, adding the United States to the “For calls to” column will permit calls to the United States for the users to whom the trunk is assigned.
If you are looking to automatically prepend a prefix to any phone number (for instance, to call the United States phone numbers without a 1 in front of the 10-digit number), you can do that by clicking the “New Destination” button, and entering a 1 into the “Use prefix” column. You will notice that if nothing is entered into the “For calls to” column, the system will automatically tag that column as the “Default” destination.