COMSPHERE 3550 Series Data Service Units
2-12 February 1995 3550-A2-GB20-10
Verifying DBM Operation
If a DBM is installed, test the tributary DBM for
dial tone, and verify that the DSU can place and receive
calls.
Procedure
1. Select Bckup (F2).
2. Select Dial to establish a dialed call to the
tributary.
(Refer to Chapter 4 for the procedure for entering
telephone numbers.)
3. Select Dial to switch to the dial circuit.
4. Perform a Digital Test following the DBM path
rather than the DSU path.
(No error message should appear.)
5. Select DrBU to drop the backup call.
6. Perform a Digital Test on the DBM. Follow the
Verifying the Network procedure, selecting DBM
instead of DSU (Step 2).
Verifying TDM/Flex Operation
If a TDM/Flex is installed, perform a Digital Test on
each port.
Other Tests
The following lists the tests available on your DSU.
Refer to the Test Branch section of Chapter 4 for further
test information, as well as more detail on how to
configure and operate the DSU. Refer to Appendix A to
determine how best to access each test.
•Device Test (Devic)
•Local Loopback (LL)
•DTE Loopback (DTE)
•Digital Loopback (DL)
•Remote Digital Loopback (RL)
•Bilateral Loopback
•Digital Test (DT)
•End-to-End Test (EE)
•Bit Error Rate Test (BERT)
•Lamp Test (Lamp)