... 4,8,12,16 FXS/FXO ports PCI card Asterisk, FreeSwitch, Elastix Detecttion of busy tone, ... FSK Adjustable line gain PCI/PCI-E analog card for Freeswitch and Asterisksupport 4 to 16 FXS/ ... Demand5, Voice Mail Services6, Call Centers7, Prepaid Calling Card System8, Callback Service9, Traditional Calls/VoIP Calls Conference Hardware ... Interface: PCI 2.22, CPU 800+MHZ3, RAM 128+MB4, Linux kernel 2.4.x or 2.6 ...