Telephone User Manual

ISDN Interfaces
ISDN Testing and Troubleshooting
7-34 Strata CTX I&M 06/04
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.
Figure 7-30 Loop-back Test
CO ISDN
PRI Test
Signal
ISDN PRI
CSU
ISDN PRI
(RJ45)
JP1
(LB-ON)
JP2
(LB-ON)
1.5MHz
line
Interface
LSI
Demarcation Point
6689
BPTU or RPTU
Network
Jack
RJ48C
or RJ48X