3
Section 61150279L1-5, Issue 1
61150279L1-5A
Figure 2. BR1/10 E1 LIU and BCU
DB-9 Connector
The DB-9 female connector provides access to the
8␣ kHz and 64 kHz clock reference for DS0 logic test
equipment.
Figure 3
illustrates the DB-9 connector.
3. TESTING
Although ISDN is designed to be tested from the CO
ISDN switch it may be necessary during fault
isolation or equipment malfunction to conduct remote
testing from the local E1 LIU. The E1 LIU provides
access for both E1 loopback and BRI testing.
E1 loopback testing has two loopback modes: local
loopback and remote loopback. E1 loopbacks include:
• Providing a loopback for the local E1 data
stream.
• Providing a loopback for the remote E1 data
stream.
Table 1. Rotary Test Switch Options
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b
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L
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1
R
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2
R
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3
R
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A
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4
R
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A
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5
R
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6
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K
B
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1
T
N
.
1
T
N
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f
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d
A
SW3
DB-9
Bantam jacks
DSL selection
Loopback address
E1 BCU test DIP switch
TEST pushbutton
Figure 3. DB-9 Connector
TEST
+5 V
GND
64 kHz
8 kHz
1
2
3
4
5
6
7
8
9
NOTE
Front panel rotary switches and bantam test access
apply to TDM U-BR1TE application of BR1/10. In
FramePort application, rotary switches have no
effect, and use of bantam test access will cause
disruption of service.