ISDN Interfaces
RBSU/RBSS Interface Units
7-22 Strata CTX I&M 06/04
A cord of up to 10 meters connects the ISDN BRI RJ45 wall jack to the desktop TE-1 or TA RJ45
jack. Bellcore recommends that all TE-1 and TA devices be attached with the same standard cord
to ensure compatibility.
Figure 7-15 Modular ISDN Data Cable
The standard pinouts for ISDN jacks is the TIA-568A or TIA-568B jack as listed in Table 7-11.
The variants A and B to the TIA specification are electrically the same, only the wire colors are
different. However, you should only use one type TIA jack in a customer installation because
mixing the two may cause certain wire pairs to be swapped which would result in line faults.
Notes
• Pins are numbered left to right when looking into the jack cavity with the locking tab down.
• TIA-568A swaps pair two with pair three, changing only the color of the wires on the pins.
Electrical performance is the same.
Table 7-11 TIA-568B (RJ45) Jack – ISDN Standard Interface Modular Connector Pinout (RBSU-
NT mode
Pin Color Name Function
1 Green T2 Power 3 (not used on RBSU/RBSS)
2 Green/White R2 Power 3 (not used on RBSU/RBSS)
3 Orange/White R3 RX+
4 Blue/White R1 TX+
5Blue T1TX-
6 Orange T3 RX-
7 Brown T4 - Power 2 (not used on RBSU/RBSS)
8 Brown/White R4 + Power 2 (not used on RBSU/RBSS)
3039
Four-pair Wire
RJ-45
Eight-pole Plug
Locking Tab
