How does Huawei p8 prohibit incoming calls that are not in its address book?

Set to intercept strangers and intercept all phone calls and text messages except contacts.

Set the method to intercept strangers:

Enter "mobile phone housekeeper >"; Harassment interception > settings, turn on "harassment interception" and turn on the "intercept strangers" switch in "interception rules".

Note: 1. By default, intelligent blocking spam messages, blocking number blacklists and blocking keyword blacklists are enabled.

2. Turn on the unknown number call interception switch to intercept calls with empty number, private number and unknown number.

3. Turn on all intercept switches to intercept all incoming calls and text messages.