The Banana Phone project was an attempt at creating a robocall blocking system from off-the-shelf, readily available components.
It was first written in the Winter of 2012 as a submission for the 2013 FTC Robocall Challenge.
The unique advantage of Banana Phone is that since it is a hardware-based solution, it can be used on any landline, whether the service line is VoIP or regular PSTN.
Add a dedicated user for Banana Phone, create a some directories and install Asterisk
Tell Asterisk to where to listen for calls in sip.conf
Configure the Obi110 ATA to pass calls to your Raspberry Pi
Learn some basic concepts in Asterisk for handling calls
Copy over all the Banana Phone scripts and the dialplan, and test your installation
Enhance Banana Phone by adding voicemail functionality