Yeastar P560 PBX 100user 30channels, Basic features. Upgradeable Yeastar P560 supports 1 expansion board. You can install either EX08 board or EX30 board according to your needs. Up to 4 modules and 8 RJ11 ports are supported on the expansion board. The 8 RJ11 ports can be used to connect to different objects: FXS port (green light): For the connection of analog phones or fax machines. BRI port (orange light): For the connection of BRI lines. FXO port(red light): For the connection of PSTN lines or FXS ports of traditional PBX.