Chapter 6 Troubleshooting
T1/E1 CSU loop up & loop down codes
6-8
TC8518 Rev 2.2 User Manual
Figure 6-10 Loopback Test - T1/E1 Remote
6.8
T1/E1 CSU loop up & loop down codes
The TC8518 supports CSU up (10000) and CSU down (100) codes by automatically
enabling loopbacks. CSU line code monitoring is disabled by default and can be
configured using CLI by issuing the following command:
t1e1 loop_code_monitor_set
Alternatively one can go to the T1/E1 Diagnostic webpage and set it up there. The
options are Disabled, Enable Local and Enable Remote. By setting it to Enable
Local, the device will be monitoring the incoming T1/E1 signal going to the RJ48
port for loop codes and will enable/disable local loopback accordingly. Using the
Enable Remote setting will monitor the T1/E1 signal coming in from the remote unit
(over the OC/3 signal) and enable / disable the remote loopback accordingly.
The diagram below shows the T1/E1 signal flow and related loopbacks.