S0 bus
S0 bus (S/T or just S-bus) allows up to 8 ISDN devices. if one device is connected (I.E.: NT-1), the theoretical cable run is 1km, but is limited to 150m for 8 devices
RJ45 pinout should be
- power source or sink 3 +
- power source or sink 3 -
- transmit positive
- transmit negative
- receive positive
- receive negative
- power sink 2 -
- power sink 2 +