Diagnostic Tests for DS3
- Kelli Higdon
The IMG 2020 has a suite of tests that can be run to check the Layer 1 signal integrity. Below are the tests that are supported on the IMG 2020.
DS3 Loopback Testing
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When a span is placed into loop-back mode, the span status within the Object Table Tab of the Bearer Spans Object will indicate it is Out Of Service. The spans must be manually put back in service by selecting the Span/Offset from within Object Table Tab, right click on the Offset/Span and select In Service from drop down menu.
BERT
Use Bit Error Rate Testing (BERT) to test the quality of DS3 links and to troubleshoot problems. You send out a known bit pattern and verify the received bits against the sent pattern. A high bit error rate indicates noise on the circuit. The IMG 2020 can be configured to run Bit Error Rate Tests (BERT) on a DS3 or on individual DS1s in a DS3, which includes:
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Generate a test pattern to be verified by a piece of external test equipment or another IMG 2020 |
Monitor a test pattern when configuring both the transmit and receive. |
Insert bit errors |
Starting and Stopping a BERT Test
Right-click on the desired DS3 entry and select New BERT Test.# Select options as required in the fields. See the BERT pane reference for more information.
Note: DS1’s do not need to be configured when testing the entire DS3 circuit.When finished configuring the options, commit the configuration. Testing starts as soon as the configuration has been committed. While in test mode, the span status LED for the DS3 or DS1s will flash orange.
Results of BERT Test
The results of the test are shown in the Status fields of the BERT pane. The following information is reported in table below.
Status | Description |
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Monitor Status | Displays the status of the object that is being monitored, since this is a BIT map these fields could be concatenated together. |
Bits Received | Displays the number of bits received in Megabits. |
Errors Received | Displays the number of bit errors received. |
Elapsed Time | Displays the time it took for test to complete. |
Error Mode | Displays whether error mode has been enabled or disabled in the BERT test. |