... four extension modules Constitute,Expansion modules as needed, matching FXS and FXO interfaces,Uses the powerful performance processing IBM ... 16-32FXS ,16-32FXO, 16FXS +16 FXO Voice card;In short, FXS port and FXO ports can choose any combination!(Serial ... Interface: RJ11, CONSOLE port, baud rate 38400HzSignaling and controlSignalling: FXS, FXO Loop StartBand signaling: DTMF (TIA464A), the user can ...