How can you intercept certain numbers on your system. For example, you don’t want to allow any international calls at all. You can create a Misc Application that traps a number or range of numbers and pleasantly informs the user they can not do that. For example:
011X. maybe the pattern (in North America) to recognize all international calls. So you would create a Misc App call StopInternational and as the feature code you would put ‘_011X.’ for that call. Next, point it to a pleasant announcement (using the annoucement module) that tells them they can’t do that and then as the destination of the annoucement, to the core destination of congestion or busy.
This will pleasantly stop all calls to that number. (of course you could always have created a password for the international calls - but you would not be presented with this annoucement then).
Another example you may want to use for this is a way to educate user they no longer need to dial 9 to place an outbound call. Just put the appropriate pattern for your numbers as Misc Apps and follow the same steps.