CTC Union ETU-01A - Page 60

Chapter 5.Loop Back & BERT Testing
60
May 2011
Data Port local analog loop back.
Data Port local analog loop back is performed by connecting the data channel transmit data
(TD) to the input of the receive path (RD) before the CSU, as shown in Figure 5-6. The test signal
is provided by the local DTE.
Figure 5-6. Data Port local analog loop back
Data Port local digital loop back.
Data Port local digital loop back is performed by connecting the local data channel receive
data (RD) to the data channel transmit input (TD), as shown in Figure 5-7. The test signal is then
provided by the local E1 or by the remote user DTE.
Figure 5-7. Data Port local digital loop back
User
DTE
Data
Port
E1
E1 LINE
LOCAL ETU-01A
DSU
CSU
User
DTE
Data
Port
E1
E1 LINE
LOCAL ETU-01A
DSU
CSU