This is an example of how a $40 Raspberry Pi 2 with installed Asterisk and FreePBX as GUI can be used as a home based PBX for extremely cheap international calls I made for myself in a couple of days:
This is an example of how a $40 Raspberry Pi 2 with installed Asterisk and FreePBX as GUI can be used as a home based PBX for extremely cheap international calls I made for myself in a couple of days: