Toshiba CTX28 manual Loop-back Test

ISDN Interfaces

ISDN Testing and Troubleshooting

The above response indicates the test was passed and that the B1, B2 and D channels and the wire connections for the tested device are operating properly.

If the Strata CTX responds with:

TEST FAIL

The test failure could be caused by:

•U-terminal is in busy state when the test was started.

•U-terminal is in TQ/ACB/ACD mode when the test was started

•The Strata CTX BRI PCB slot or circuit number was not entered correctly.

•U-terminal can not support loop back testing U-terminal, BRI PCB, or wiring is defective.

If the Strata CTX responds with:

TEST EXIT

Test exit could be caused by:

•The Strata CTX processor did not get test results from the BRI circuit within five seconds from start of the test.

•U-terminal or BRI circuit was unplugged during the test.

•User made the exit request during testing

Loop-back Test

The BPTU and RPTU have loop-back test jumpers that enable physical connections (cables/jacks/ plugs) between the PCB, CSU, and the network PRI line to be tested (see Figure 7-30). The tests check that the CSU receives and transmits the PRI signal properly in both directions. The test signals, generated by the Network PRI provider, pass through the CSU and loop around the BPTU or RPTU. The BPTU or RPTU sends the received test signal back through the CSU to the Network and the Network detector checks for a valid signal.

CO ISDN	ISDN PRI
PRI Test
Signal

Network Jack RJ48C or RJ48X

Demarcation Point

CSU

BPTU or RPTU

ISDN PRI	JP1
(RJ45)	(LB-ON)

1.5MHz line Interface

LSI

JP2

(LB-ON)

6689

Figure 7-30 Loop-back Test

7-34 Strata CTX I&M 06/04