I hunted for that ‘whitelisting for fun and profit’ and found nothing, but while doing so found where he’d been woken up at 5 am on new year’s day by a spammer and wrote an IVR to prevent spam - he called that Of Robocalls and Whitelists . (Necessity really is the mother of all invention. 
) Unfortunately, I don’t see how this could be easily applied to this situation… we do not want to force people to press a button to be connected though.
It would not be difficult for me to code something in perl to accomplish exactly what is needed, but I do not know the asterisk system well enough to know if this could even be integrated with it or not. I’m that when a call comes in, asterisk presents the CID to my script, then routes the call based on the script’s response… is something like this possible? 