... FXS/FXO ports PCI card Asterisk, FreeSwitch, Elastix Detecttion of busy tone, DTMF, FSK Adjustable line gain PCI/PCI-E analog card for Freeswitch and ... Centers7, Prepaid Calling Card System8, Callback Service9, Traditional Calls/VoIP Calls Conference Hardware and software requirements: 1, Interface: PCI 2.22, CPU 800 ...