DISA combined with a Callback basically eliminates the issue of hacking by spoofing CID.
https://wiki.freepbx.org/display/FPG/Callback+Module+User+Guide
https://wiki.freepbx.org/display/FPG/DISA+User+Guide
DISA combined with a Callback basically eliminates the issue of hacking by spoofing CID.
https://wiki.freepbx.org/display/FPG/Callback+Module+User+Guide
https://wiki.freepbx.org/display/FPG/DISA+User+Guide