User guide

August 2001 141
Troubleshooting
Test individual regions of the cabling using a cable to connect
transmit and receive leads at points along a trunk. This mode
loops data back to either the board or CO depending on which
end transmits the data and how you set up the loopback.
Figure 23 shows a loopback using a cable to physically connect
the transmit and receive leads along trunk A.
Figure 23. Cabling Loopbacks in E1
Board
Data stream to trunk A
Data stream from trunk A
CO