References

https://www.rapid7.com/blog/post/2018/05/24/how-to-build-your-own-caller-id-spoofer-part-1/
https://www.youtube.com/watch?v=DZ0czppbamo
https://i3forum.org/public_html/wp-content/uploads/2020/11/i3f-Technical-Report-CLI-spoofing-Technical-Report-final.pdf
https://www.rapid7.com/blog/post/2018/05/24/how-to-build-your-own-caller-id-spoofer-part-2/

https://www.youtube.com/watch?v=DZ0czppbamo

https://www.social-engineer.org/wiki/archives/CallerIDspoofing/CallerID-SpoofingWithAsterisk.html

https://support.voipcloud.online/hc/en-us/articles/201488150-Asterisk-SIP-Trunk-Guide

https://starcompartners.com/tollfree-termination

https://www.youtube.com/watch?v=F1Wv3I_OIds&list=LL&index=1

http://www.asteriskdocs.org/en/3rd_Edition/asterisk-book-html-chunk/DeviceConfig_id216341.html
https://www.voip-info.org/asterisk-firewall-rules/