Incoming "fake" calls, how to block them?

[Chris57]

Hello, I´m running V18 on Windows 10.

I´m getting fake incoming calls looking like this (examples):
FROM:
*: PBX (100)
*:Asterisk (100)
*:Grandstream (100)
*: (546004591618)

while "real" calls look like this:
*:33684571128 (33684571128)

Is there a way to block calls without a "real" incoming number? Or any other ideas how to get rid of these calls?

Thanks!

 

[bitn2]

This will be blocked by 3cx automatically. In most cases you can adjust your firewall port 5060 to your sip trunk network to get rid of this calls.