T1/E1 Csu/Dsu Connections - Cisco Catalyst 2000 Configuration Handbook

T1/E1 CSU/DSU Connections

You can also make back-to-back connections between two routers with integrated T1/E1
CSU/DSUs using a specially made cable. Again, the transmit and receive pairs are crossed
in the cable. Table A-5 lists the pinout connections of both RJ-48 (an RJ-45 will do) ends
of the cable.
Table A-5 RJ-48 Connector Pinouts for Back-to-Back T1/E1 CSU/DSU Connections
RJ-48 Pin
End A
1
2
3
4
5
6
7
8
Description
End A
RX (input)
RX (input)
–
TX (output)
TX (output)
–
–
–
Appendix A: Cabling Quick Reference 269
Description
End B
TX (input)
TX (input)
–
RX (output)
RX (output)
–
–
–
RJ-48 Pin
End B
4
5
3
1
2
6
7
8