This test is destructive.
The Internal Looparound Test loops the transmitted DS1 bit stream back into the board receiver. The loop occurs just before the DS1 facility interface. The test is highly destructive and can only be initiated by a reset board location command.
All of the trunks on the DS1 must first be busied out using the busyout board location command before the Internal Looparound Test can be executed. If the transmitted and received bit patterns on a trunk are different, the test fails.
All trunks of the DS1 are restored to the in-service state after release board location is entered.
This test is run on the following maintenance object:
