Troubleshooting guide

Section 7, User Interface Guide - DLP-602, MUX Module Acceptance Test Procedure
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PROCEDURE
NOTE
Ensure that the DS3 timing is configured to LOCAL during these
tests.
Ensure that the STS-1 timing is configured to FREE-RUN or
EXTERNAL during these tests.
DS1 Daisy-chain to DS3 (Hard) Loopback
This test loads up all 28 ports of the MX2820 system with traffic at the same time.
1. At the DSX-3 cross connect, use a test cord to loop the DS3 from the MX2820 back to
itself.
2. At the DSX-1 cross connect, insert the TX OUTPUT of the DS1 test set into the INPUT of
the first DS1 channel on the MX2820 system.
3. At the DSX-1 cross connect, install a Bantam test cord from the OUTPUT of the first DS1
channel to the INPUT of the second DS1 channel. Then connect a second Bantam test
cord from the OUTPUT of the second DS1 channel to the INPUT of the third DS1 channel.
Repeat this procedure for all 28 DS1 channels.
4. Connect the OUTPUT of the 28th DS1 channel to the RX INPUT of the DS1 test set.
5. Set the test set options for ESF/B8ZS and run a standard BERT test per operating
company practices.
6. All alarms should clear, and the BERT test should run error free.
7. If problems are encountered, refer to the appropriate subsections in “Section 5, User
Interface Guide” to help in troubleshooting and isolating the problem.
8. This step completes the DS1 Daisy-chain to DS3 (hard) Loopback test. If other acceptance
tests are to be performed at this time, proceed to those tests within this procedure.
Otherwise this procedure is complete.
DS1 to DS3 “Head-to-Head” Test
This test tests one DS1 channel at a time by using a DS1 test set at the DSX-1 cross connect
and a DS3 test set at the DSX-3 cross connect.
1. At the DSX-3 cross connect bay, connect the DS3 test set to the DS3 coming from the
MX2820 system. Configure the test set to drop out DS1 #1 and to run a BERT on it in
ESF/B8ZS mode.
2. At the DSX-1 cross connect bay, connect the DS1 test set to the first DS1 channel of the
MX2820 system. Configure the test set for the same BERT pattern as the DS3 test set is
sending.
3. Verify data passes error free between the DS3 test set and the DS1 test set.