Lucent Technologies DEFINITY Installation For Adjuncts And Peripherals page 148

DEFINITY ECS Release 8.2
Installation for Adjuncts and Peripherals 555-233-116
9 DS1/T1 CPE Loopback Jack
Loopback Testing Without a Smart Jack
Configurations Using Fiber Multiplexers
Use the loopback jack when customer premises DS1 wiring connects to an on-
site fiber multiplexer (MUX) and allows wiring to the network interface point on
the MUX to be remotely tested. This requires that ICSUs be used on DS1 wiring
to the MUX.
Fiber MUXs can take the place of Interface termination feeds as shown in
34, Figure
procedures as metallic spans. Note the following points:
1. Fiber MUXs may have loopback capabilities that can the service provider
can activate from the CO end. These may loop the signal back to the CO
or back to the DS1 board. If the MUX provides the equivalent of a line
The far-end ICSU's line loopback. Activate this test at the
management terminal by entering test DS1-loop location far-csu-
loopback-test-begin. Terminate this test by entering test DS1-loop
location end-loopback/span-test. Bit error counts are examined
as described in the "DS1 Span Test" section. This test only isolates
problems to Section 2 wiring if there are no problems in the wiring
between the far-end CO and the far-end ICSU. Coordinate this test
with the DS1 service provider.
Failure of any of the above tests (a, b, or c) indicate a problem in
Section 2. This could mean bad loopback jack -to-"dumb" block
cabling, but is more likely to indicate a problem somewhere
between the "dumb" block and the CO. This is the responsibility of
the DS1 service provider.
If the DS1 Span Test confirms that there are no problems in Section
1, the technician should proceed as follows to avoid unnecessary
dispatch.
1. Identify and contact the DS1 service provider.
2. Inform the DS1 provider that loopback tests of the CPE
wiring to the "dumb" block (section 1) showed no problems.
3. If the far-end ICSU line loopback test failed, inform the DS1
provider.
4. Request that the DS1 provider perform a loopback test of
their portion of the Section 2 wiring by sending someone out
to loop Section 2 back to the CO at the "dumb" block.
If this test fails, the problem is in the service provider's
wiring.
If the test passes, the problem is in the cable between the
loopback jack and the "dumb" block. Replace the loopback
jack.
35, Figure 36, and Figure 37. Test these spans using the same
Issue 1
April 2000
126
Figure