... tone, DTMF, FSK Adjustable line gain PCI/PCI-E analog card for Freeswitch and Asterisksupport 4 to 16 FXS/FXO ports Applications: 1 ... Calls/VoIP Calls Conference Hardware and software requirements: 1, Interface: PCI 2.22, CPU 800+MHZ3, RAM 128+MB4, Linux kernel ... using: 1, Temperature Operation: 0 to 80°C2, Temperature Storage: -35°C to 120°C3, Humidity: 10% to 90% Non-condensing4, Voltage: 5V ...