... , Elastix Detecttion of busy tone, DTMF, FSK Adjustable line gain PCI/PCI-E analog card for Freeswitch and Asterisksupport 4 to 16 ... Calls/VoIP Calls Conference Hardware and software requirements: 1, Interface: PCI 2.22, CPU 800+MHZ3, RAM 128+MB4, Linux kernel ...