On the YBT1 my line coding is not stable. It keeps changing types from AMI to B8ZS. What could cause this? Is something wrong with the line I need to fix?

On the YBT1 my line coding is not stable. It keeps changing types from AMI to B8ZS. What could cause this? Is something wrong with the line I need to fix?

This is usually due to insufficient zeroes in the received data. B8ZS line coding needs 8 zeroes in a row to trigger the insertion of bipolar violations (BPV's). If the BPV's can't be inserted, the
YBT1 can't identify it as B8ZS.