Screening can be set up by adding the unwanted caller’s phone number to a blacklist. All incoming calls from blacklisted phone numbers are automatically rejected.

Refer to our doc on screening an incoming call for instructions.

In addition, Plivo has taken precautions to prevent unwanted inbound calls. All Plivo phone  numbers are blocked for 30 days after it is unrented from another Plivo account. This prevents unwanted inbound calls for when these phone numbers are rented again. This precaution also ensures that the previous owner has enough time to transition all the traffic from the released number to another number.