RJ48 Wiring Schematic Pinout Diagram and Color Code. The RJ48 is a registered jack. It is used for T1 and ISDN termination and local area data channels/subrate digital services. The RJ48 use the 8P8C modular plug and 2 pairs of the wires, one pair for transmitting and one pair for receiving data. It uses the 8 position modular connector. RJ-48X is a variation of RJ-48C that contains shorting blocks in the jack so that a loopback is created for troubleshooting when unplugged.
RJ48 Wiring Schematic Pinout Diagram and Color Code