FreeSwitch

Links

FreeSwitch

• Documentation: https://developer.signalwire.com/freeswitch/FreeSWITCH-Explained/  
• Github: https://github.com/signalwire/freeswitch 

FreeSwitch GUI

• FusionPBX - FusionPBX can be used as a highly available single or domain based multi-tenant PBX, carrier grade switch,...
• OV500 - OV500 is Open Source VoIP Billing switching and routing Solution.