If you get annoying telemarketing calls then it’s really simple to block the caller ID with FreePBX. First you need to ensure the caller ID module is installed, see here for more info – http://sysadminman.net/blog/2014/freepbx-2-11-guide-updating-and-installing-modules-5922
Blocking a caller via the Web GUI
First we need to go to the Blacklist menu option
Now we can block a caller based on their ID, or block all anonymous callers
Three things to note –
Blocking a caller via the phone
Probably a much more useful option is to block a caller after you receive a call from them on your extension. To do this, after hanging up on the caller, dial *32 and you should hear a messaging directing you to press 1 to block the last caller. The callers ID should be read to you.