A Class of Service will limit specific extensions from dialling certain numbers or prefixes. For example, you could stop selected extensions from calling international numbers.
To set this up, go to Classes of Service and press Add New. Give it an appropriate name something like ‘no international calls’ and press Save. By default, internal and external calls will be set to Allow but these can be changed to suit your needs, and exceptions can be added to override these default options.
Once saved, you will see the Exceptions tab at the top of the page. On this tab, click Add New to add a new exception.
To block all international calls, set the type to External Calls and enter ‘00’ in Number or Prefix and set to Forbid. If you want to allow one international code or number to be called, simply create another exception and enter Number or Prefix as 001 which will enable dialling America.
If it is only one area in America that you would like to allow, use a longer prefix like 001378400 which enables calling all 001378400 0000 – 9999 numbers.
The longest prefix is used/matched first.
To apply this to an extension, go to Extensions and there will be an option Class of Service. Choose the one you have just created and save this. The changes will take place immediately on the phone/extension.
You can also set a Time Group on the Details tab, where you can then select the allow option as Allow if Time Group is Active or Allow if Time Group is not Active. This will then follow the rules of the selected Time Group so you could allow international calls only during your working hours.