If you want to run loopback tests or bit error rate tests on channelized T3 interfaces, you must enable testing at the T3 or T1 layer. See Interface Stack for a description of the layers.
For a list of the modules that support bit error rate tests (BERTs) and remote loopback, see ERX Module Guide, Appendix A, Module Protocol Support.
![]() |
Note: BERTs are supported on frame-based channelized T3 interfaces, with the exception of the CT3/T3 line module used with the 3-port CT3/T3 I/O module. |