The FRM220-FXO/FXS is a POTS (Plain Old Telephone System) over fiber converter/extender. The POTS connection uses a standard RJ-11Cmodular connector for one copper pair connection. A pair of FRM220-FXO/FXS is required to implement an end to end system. FXOmode connects to a telephone line (PSTN) or PBX station line and has ability to detect ringing voltages and to act as a telephone. FXSmode is the reciprocal unit and has ability to act as PSTN and connects to a telephone device. When the FRM220-FXO/FXS card is placedin the FRM220 rack with NMC management, in-band management allows configuring and viewing the card and remote converter'sstatus, type, version, fiber link status, on hook status and alarms. Both card and remote can be configured to enable or disable the port,reset the port and set the FXO or FXS mode. When configured in an FXS to FXS fashion, a private "hot line" or direct line is created. Whenplaced in a single slot chassis and used standalone without management, the card may be configured by DIP switch.