How to make phone calls from RasPI (RasberryPi) ? 

 NeuTrafiX is a platform that allows any SIP protocol enabled device to connect to its network and send calls to any destination in the world at wholesale rates and by billing per second not per minute, We have worked with IncrediblePBX open-source project to bring you a pre-configured  NeuTrafiX SIP Trunks so you can imitate calls from your IoT device or any RasberryPi based project in minutes.

Incredible PBX is a secure and feature-rich implementation of the terrific Asterisk ® PBX. By rethinking the PBX security model from the ground up, Incredible PBX was engineered to provide rock-solid security while delivering the most comprehensive collection of Asterisk utilities available on the planet. for more details on this open source project visit http://incrediblepbx.com .

Read this article to learn how to setup incrediblePBX with RasPi