... FXS/FXO ports PCI card Asterisk, FreeSwitch, Elastix Detecttion of busy tone, DTMF, FSK Adjustable line gain PCI/PCI-E analog card for Freeswitch ... , Prepaid Calling Card System8, Callback Service9, Traditional Calls/VoIP Calls Conference Hardware and software requirements: 1, Interface: PCI 2.22, CPU ... 800+MHZ3, RAM 128+MB4, Linux kernel 2.4.x or 2.6.xSize and Weight5 ...