Callsfree mobile or landlines though internet

Hello,
Respected friends, I want to know that we can make call absolute free on mobile or landlines though internet. I can try many website but it is not free or not good services. only in Indian services free. if you know about that please tell me friends. I have search many website but after installation the software they want money. and not in indian services. services is provide in Canada or America. and European country.