Avaya 03-300430 User Manual
Communication Manager Maintenance-Object Repair Procedures
2460 Maintenance Procedures for Avaya Communication Manager 3.0, Media Gateways and Servers
Far CSU Loop-Back Test (#1213)
This test is destructive.
The Far CSU Loopback (R-LLB) test causes a loopback at the far-end CSU and tests all
circuitry and facilities from the local DS1 board to the far-end CSU.
The test is destructive and can only be initiated by test ds1-loop location
far-csu-loopback-test-begin
Each trunk or port on the UDS1 Interface circuit pack must be busied out using busyout
board location before running the Far CSU Loopback test.
If the DS1 is administered for ami-zcs line coding, and the far-end CSU is not a 120A1 CSU
module or the 401A T1 sync splitter, density protection must be disabled on the CSU/T1SS
during the test due to the large number of zero’s in the 3-in-24 test pattern.
The Far CSU Loopback test has the UDS1 Interface circuit pack transmit a loopback activation
code to the remote CSU, waits up to 15 seconds for return of the code to verify the loopback
has been established, transmits a framed 3-in-24 test pattern, begins counting bit errors in the
received test pattern, and returns a PASS result. If the loopback is not established within the 15
seconds, the test fails.
The status of the Far CSU Loopback test is available in the hardware error log via Error Type
3901. Several distinct Aux values give the user information about the status of the test.
The list measurements ds1 summary command shows the length of time the test has
The Far CSU Loopback (R-LLB) test causes a loopback at the far-end CSU and tests all
circuitry and facilities from the local DS1 board to the far-end CSU.
The test is destructive and can only be initiated by test ds1-loop location
far-csu-loopback-test-begin
Each trunk or port on the UDS1 Interface circuit pack must be busied out using busyout
board location before running the Far CSU Loopback test.
If the DS1 is administered for ami-zcs line coding, and the far-end CSU is not a 120A1 CSU
module or the 401A T1 sync splitter, density protection must be disabled on the CSU/T1SS
during the test due to the large number of zero’s in the 3-in-24 test pattern.
The Far CSU Loopback test has the UDS1 Interface circuit pack transmit a loopback activation
code to the remote CSU, waits up to 15 seconds for return of the code to verify the loopback
has been established, transmits a framed 3-in-24 test pattern, begins counting bit errors in the
received test pattern, and returns a PASS result. If the loopback is not established within the 15
seconds, the test fails.
The status of the Far CSU Loopback test is available in the hardware error log via Error Type
3901. Several distinct Aux values give the user information about the status of the test.
The list measurements ds1 summary command shows the length of time the test has
been running (Test Duration field) and number of bit errors detected (Loopback/Span Test
Bit-Error Count field). If the test pattern is being passed through the loopback cleanly, the
number of bit errors should be very low. The command will also display the type of Loopback/
Span test executing (Test field), the type of pattern generated for the type of Loopback/Span
test (Pattern field), and whether the pattern (i.e., 3-in-24 Pattern) is synchronized
(Synchronized field).
To terminate the test, enter test ds1-loop location end-loopback/span-test or
release board location. Using release board restores each trunk or port on the UDS1
Bit-Error Count field). If the test pattern is being passed through the loopback cleanly, the
number of bit errors should be very low. The command will also display the type of Loopback/
Span test executing (Test field), the type of pattern generated for the type of Loopback/Span
test (Pattern field), and whether the pattern (i.e., 3-in-24 Pattern) is synchronized
(Synchronized field).
To terminate the test, enter test ds1-loop location end-loopback/span-test or
release board location. Using release board restores each trunk or port on the UDS1
Interface circuit pack to the in-service state.
Table 871: Test #1213 Far CSU Loop-Back Test
Error
Code
Code
Test
Result
Result
Description / Recommendation
ABRT
Internal system error
1. Retry test ds1-loop location
far-csu-loopback-test-begin at 1-minute intervals up to 5
times.
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